Antitumor Effect and Gut Microbiota Modulation by Quercetin, Luteolin, and Xanthohumol in a Rat Model for Colorectal Cancer Prevention

Colorectal cancer stands as the third most prevalent form of cancer worldwide, with a notable increase in incidence in Western countries, mainly attributable to unhealthy dietary habits and other factors, such as smoking or reduced physical activity. Greater consumption of vegetables and fruits has been associated with a lower incidence of colorectal cancer, which is attributed to their high content of fiber and bioactive compounds, such as flavonoids. In this study, we have tested the flavonoids quercetin, luteolin, and xanthohumol as potential antitumor agents in an animal model of colorectal cancer induced by azoxymethane and dodecyl sodium sulphate. Forty rats were divided into four cohorts: Cohort 1 (control cohort), Cohort 2 (quercetin cohort), Cohort 3 (luteolin cohort), and Cohort 4 (xanthohumol cohort). These flavonoids were administered intraperitoneally to evaluate their antitumor potential as pharmaceutical agents. At the end of the experiment, after euthanasia, different physical parameters and the intestinal microbiota populations were analyzed. Luteolin was effective in significantly reducing the number of tumors compared to the control cohort. Furthermore, the main significant differences at the microbiota level were observed between the control cohort and the cohort treated with luteolin, which experienced a significant reduction in the abundance of genera associated with disease or inflammatory conditions, such as Clostridia UCG-014 or Turicibacter. On the other hand, genera associated with a healthy state, such as Muribaculum, showed a significant increase in the luteolin cohort. These results underline the anti-colorectal cancer potential of luteolin, manifested through a modulation of the intestinal microbiota and a reduction in the number of tumors.

The impact of timing, type, and method of instillation of intraperitoneal local anaesthetic in laparoscopic abdominal surgery: a systematic review and network meta-analysis

BACKGROUND

Pain is common after laparoscopic abdominal surgery. Intraperitoneal local anaesthetic (IPLA) is effective in reducing pain and opioid use after laparoscopic surgery, although the optimum type, timing, and method of administration remains uncertain. We aimed to determine the optimal approach for delivering IPLA which minimises opioid consumption and pain after laparoscopic abdominal surgery.

METHODS

MEDLINE, Embase, Scopus, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were systematically searched for randomised controlled trials comparing different combinations of the type (bupivacaine vs lidocaine vs levobupivacaine vs ropivacaine), timing (pre-vs post-pneumoperitoneum at the beginning or end of surgery), and method (aerosol vs liquid) of IPLA instillation in patients undergoing any laparoscopic abdominal surgery. A network meta-analysis was conducted to ascertain the optimum approach for delivering IPLA resulting in the least cumulative opioid consumption and pain (overall and localising to the shoulder) 24 h after surgery. Certainty of evidence was evaluated using Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) assessments (PROSPERO ID: CRD42022307595).

RESULTS

Twenty-five RCTs were included, among which 15 different combinations of delivering IPLA were analysed across 2401 participants. Aerosolised bupivacaine instilled at the end of surgery, before deflation of the pneumoperitoneum, was associated with significantly less postoperative opioid consumption compared with all other approaches for delivering IPLA (98.7% of comparisons; moderate certainty), aside from liquid levobupivacaine instilled before surgery and during or after creation of the pneumoperitoneum (mean difference -11.6, 95% credible interval: -26.1 to 2.5 i.v. morphine equivalent doses). There were no significant differences between different IPLA approaches regarding overall pain scores and incidence of shoulder pain up to 24 h after surgery.

CONCLUSIONS

There are limited studies and low-quality evidence to conclude on the optimum method of delivering IPLA in laparoscopic abdominal surgery. While aerosolised bupivacaine instilled at the end of surgery but before deflation of the pneumoperitoneum minimises postoperative opioid consumption, pain scores up to 24 h did not differ between the different modalities of delivering IPLA. The generalisability of these results is limited by the lack of utilisation of non-opioid analgesics in most trials.

SYSTEMATIC REVIEW PROTOCOL REGISTRATION

PROSPERO CRD42022307595.

Clinical experience with intraperitoneal sodium thiosulphate for calciphylaxis in peritoneal dialysis: A case series

Calciphylaxis is an uncommon but life-threatening syndrome in end-stage kidney disease, characterised by painful medial and intimal calcification of the arterioles in the deep dermis and subcutaneous tissues. Intravenous sodium thiosulfate serves as an off-label but effective treatment in haemodialysis patients. However, this approach confers considerable logistical challenges for affected peritoneal dialysis patients. In this case series, we demonstrate that intraperitoneal administration can be a safe, convenient and long-term alternative.

Systemic and Brain Pharmacokinetics of Milnacipran in Mice: Comparison of Intraperitoneal and Intravenous Administration

Milnacipran is a dual serotonin and norepinephrine reuptake inhibitor, clinically used for the treatment of major depression or fibromyalgia. Currently, there are no studies reporting the pharmacokinetics (PK) of milnacipran after intraperitoneal (IP) injection, despite this being the primary administration route in numerous experimental studies using the drug. Therefore, the present study was designed to investigate the PK profile of IP-administered milnacipran in mice and compare it to the intravenous (IV) route. First a liquid chromatography-mass spectrometry (LC-MS/MS) method was developed and validated to accurately quantify milnacipran in biological samples. The method was used to quantify milnacipran in blood and brain samples collected at various time-points post-administration. Non-compartmental and PK analyses were employed to determine key PK parameters. The maximum concentration (Cmax) of the drug in plasma was at 5 min after IP administration, whereas in the brain, it was at 60 min for both routes of administration. Curiously, the majority of PK parameters were similar irrespective of the administration route, and the bioavailability was 92.5% after the IP injection. These findings provide insight into milnacipran's absorption, distribution, and elimination characteristics in mice after IP administration for the first time and should be valuable for future pharmacological studies.

Sterility of antibiotic-admixed peritoneal dialysis solution over time

BACKGROUND

Intraperitoneal antibiotics may be required daily for up to three weeks to treat peritoneal dialysis (PD)-related peritonitis. In some jurisdictions, antibiotic-admixed PD solutions are required to be used within 24 h due to concerns regarding microbial contamination and growth. This requires patients to attend the PD unit daily or alternatively for staff to perform home delivery with associated transport, staffing and cost implications.

OBJECTIVE

The aim of this study was to determine if significant microbial growth occurs in PD solutions following their injection with antibiotic or sterile water.

METHODS

Twelve PD solution bags were admixed with cefazolin sodium 1 g, diluted in 10 mL sterile water, while a further 12 PD solution bags were admixed with 10 mL sterile water using aseptic technique (AT) under supervision. All bags were stored at room temperature. Three bags from each experimental group were sampled for microbiologic culture at 0-, 24-, 48- and 72-h intervals.

RESULTS

One sterile water admixed bag sampled at 24 h yielded a Corynebacterium spp. after microbiologic culture. A repeat specimen from the same bag at day nine returned a negative culture result. All other sterile water and cefazolin admixed bags returned negative culture results at all time points.

CONCLUSIONS

Antibiotic-admixed PD solutions prepared using AT and stored at room temperature remained sterile for up to 72 h. This suggests that patients can be safely issued with a supply of antibiotic-admixed PD bags for up to three days at a time.

The Association Between Serum Vancomycin Level and Clinical Outcome in Patients With Peritoneal Dialysis Associated Peritonitis

Introduction

Intraperitoneal (IP) vancomycin is often first-line empiric therapy and then maintenance therapy for peritoneal dialysis (PD) peritonitis. However, how vancomycin serum levels correlate with clinical outcomes remains unclear.

Methods

We conducted a retrospective single-center adult cohort study of 98 patients with PD peritonitis treated with IP vancomycin between January 2016 and May 2022. The association between nadir vancomycin level and cure was evaluated in a logistic regression model, first unadjusted and then adjusted for age, sex, weight, glomerular filtration rate (GFR), and total number of days on PD. Vancomycin was assessed both as a continuous exposure (per 1 mg/l increase) and as a categorical exposure (<15 mg/l vs. ≥15 mg/l). A receiver operating characteristic curve (ROC) was created to explore nadir vancomycin level thresholds in an attempt to identify an optimal target level during treatment.

Results

Of the patients, 81% achieved cure, and patients with nadir vancomycin level ≥15 mg/l were 7.5 times more likely to experience cure compared to those with a nadir level <15 mg/l (odds ratio [OR] 7.58, 95% confidence interval [CI] 1.71-33.57, P = 0.008). Weight, GFR, days on PD, sex, and age were not independently associated with outcome. The vancomycin level with the greatest discriminatory capacity for cure on the ROC analysis was 14.4 mg/l.

Conclusion

Increasing IP vancomycin serum levels are associated with increased odds of cure; and maintaining vancomycin serum levels above 14-15 mg/l throughout the course of PD peritonitis treatment is likely to improve clinical outcomes.

Unique cases of large and small bowel obstruction in intraperitoneal renal transplantations: a case series and review of literature

Bowel obstruction is a common cause for the acute abdomen with different aetiologies that shapes subsequent management plans. Small bowel obstruction often develop due to intra-abdominal adhesions in patients with prior abdominal surgery and for large bowel obstructions, more commonly due to tumours and lesions. Disruptions to normal intra-abdominal anatomy as seen in pancreatic-kidney transplantation or kidney transplant alone can result in increased risk of bowel obstruction-especially if the donor graft is implanted within the intraperitoneal plane. We present two patients from separate institutions with history of simultaneous pancreas-kidney (SPK) transplantation (Patient 1) and intraperitoneal renal (Patient 2) transplant whom both presented with bowel obstruction requiring surgical intervention. Given the specificity and operative intricacies of our cases, we aim to present our findings and surgical management of these rare presentations in hopes of increasing awareness to this uncommon but significant cause of bowel obstruction in a transplant patient.

Stability and compatibility of intraperitoneal antimicrobials in peritoneal dialysate solutions

To optimise antimicrobial administration in patients with peritoneal dialysis (PD)-related peritonitis, healthcare providers need literature-based information to develop patient-centred pharmacotherapeutic plans. Traditional PD solutions promote osmosis using dextrose or icodextrin with a lactate buffer. Newer PD solutions have modified the osmotic vehicle and buffer. Knowledge of antimicrobial compatibility and stability with newer PD solutions will assist with determining the route of antimicrobial administration as compatible and stable solutions could be delivered directly to the peritoneum using intraperitoneal administration. This review updates the compatibility and stability of antimicrobial additives in newer PD solutions for PD-related peritonitis.

Acute and sub-acute toxicity study reveals no dentrimental effect of formononetin in mice upon repeated i.p. dosing

AIM

Formononetin is a phytoestrogen which possess different pharmacological activities. The intraperitoneal route permits the identification of target organs involved in toxicity without compromising the molecule's bioavailability. The current study investigated the safety profile of intraperitoneal formononetin in Swiss albino mice.

MATERIAL AND METHODS

For acute toxicity study, formononetin administered intraperitoneally to mice at the doses of 5, 50, 100, 150, 200, and 300 mg/kg for 14 days. For the subacute toxicity study, mice were intraperitoneally administered with formononetin (12.5, 25, and 50 mg/kg) daily for 28 days.

RESULTS

During the acute study, no deteriorating effect was observed on body weight, food and water intake, no behavioral changes were observed in animals. The lethal dose 50% (LD50) of formononetin was determined to be 103.6 mg/kg of BW, with a no observed adverse effect level (NOAEL) of 50 mg/kg of BW. Mortality was observed in the 300 mg/kg dose group and histopathological changes such as a mild degree of diffuse granular degeneration in the liver but for rest all doses did not have any adverse effect. In subacute study, no signs of adverse effects, mortality, no changes in body weight, food and water intake, and hematological and biochemical parameters were observed. Histopathology of subacute study indicates, formononetin did not have any noxious effect on organs.

CONCLUSION

Formononetin shows mortality at acute dose 300 mg/kg and LD50 at 103.6 mg/kg of BW, with a NOAEL of 50 mg/kg of BW, rest all doses for acute and sub-acute are safe when given intraperitoneally.

Isolated free intraperitoneal fluid in young male after blunt abdominal sport trauma: two case reports from the World Cup 2022

The presence of isolated intraperitoneal free fluid (IFIPF) indicates the presence of mesenteric, organ, or bowel injury, which necessitates surgical exploration. The advances in computerized tomographic scanning (CT scan) allow even smaller amounts of IFIPF being detected. However, the clinical significance of IFIPF following blunt abdominal trauma remains not well-studied. Moreover, IFIPF is an unexpected condition in healthy male in the absence of mesenteric or organ injury on abdominal imaging. Herein, we presented two cases with IFIPF detected by CT scan in two healthy football male players during the World Cup 2022. The two players were managed conservatively and rejoined safely their football team during the same competition.

Idiopathic Spontaneous Intraperitoneal Haemorrhage (ISIH): A Diagnostic Dilemma and Its Conservative Management

Idiopathic spontaneous intraperitoneal haemorrhage (ISIH) is a rare cause of acute abdominal pain. It refers to haemoperitoneum resulting from the rupture of an intra-abdominal vessel without the preceding trauma or underlying pathology. Here, we present the case of a 17-year-old boy with acute abdominal pain. Initially, acute appendicitis was the primary differential diagnosis. Imaging demonstrated a significant volume of intra-abdominal fluid that was haemorrhagic in nature, but no active bleeding or source was identified. A conservative management approach was adopted due to the patient's clinical improvement during his admission. This case highlights the high index of clinical suspicion required to diagnose and investigate ISIH. In contrast to the historical opinion that stipulates management with a surgical intervention, this case demonstrates the possibility of conservative management in stable patients.

The Role of Hyperthermic Intraperitoneal Chemotherapy in Uterine Cancer Therapy

Endometrial cancer and uterine sarcoma represent the two major types of uterine cancer. In advanced stages, both cancer entities are challenging to treat and correlate with a meagre survival and prognosis. Hyperthermic Intraperitoneal Chemotherapy (HIPEC) is a form of localized chemotherapy that is heated to improve the chemotherapeutic effect on peritoneal metastases. The aim of the current review is to study the role of HIPEC in the treatment of uterine cancer. A literature review was conducted using the MEDLINE and LIVIVO databases with a view to identifying relevant studies. By employing the search terms "hyperthermic intraperitoneal chemotherapy", "uterine cancer", "endometrial cancer", and/or "uterine sarcoma", we managed to identify 26 studies published between 2004 and 2023. The present work embodies the most up-to-date, comprehensive review of the literature centering on the particular role of HIPEC as treatment modality for peritoneally metastasized uterine cancer. Patients treated with cytoreductive surgery, alongside HIPEC, seem to profit from not only higher survival but also lower recurrence rates. Factors such as the completeness of cytoreductive surgery, the peritoneal cancer index, the histologic subtype, or the applied chemotherapeutic agent, all influence HIPEC therapy effectiveness. In summary, HIPEC seems to represent a promising treatment alternative for aggressive uterine cancer.

[The effect of intraperitoneal administration of dexamethasone on postoperative analgesia after laparoscopic cholecystectomy: a prospective randomized controlled double-blind study]

Introduction

the effect of intravenous corticosteroids on postoperative pain has been well demonstrated; however, few studies have focused on the efficacy of intraperitoneal corticosteroid use after laparoscopic surgery. The purpose of this study was to evaluate the effect of intraperitoneal administration of dexamethasone on postoperative analgesia after laparoscopic cholecystectomy.

Methods

we conducted a prospective, randomised, double-blind, controlled study, including patients scheduled for laparoscopic cholecystectomy and randomised into two groups: the group D (receiving 16 ml: 12 ml saline and 4 ml solution containing 16mg dexamethasone) and the group T (receiving 16 ml saline). The primary endpoint was: Visual Analogue Scale (VAS) for abdominal pain during the first 24 hours after surgery. The secondary endpoints were the incidence of shoulder pain, time to first request for analgesia, the consumption of morphine in the post-intervention surveillance room (PACU), the consumption of non-opioid analgesics and the incidence of nausea and vomiting during the first 24 hours after surgery as well as the presence of complications.

Results

sixty patients were included in the study and divided into two groups of 30. Demographic parameters, duration of surgical and anesthesia procedures, as well as intraoperative fentanyl consumption were comparable between the two groups. Abdominal pain VAS values (p≤0.001), the incidence of shoulder pain (p<0.001), opioid and analgesic consumption (p<0.001) and the incidence of nausea (p=0.002) and vomiting (p=0.012) during the first 24 hours after surgery were significantly lower in group D. No complications related to dexamethasone administration were noted.

Conclusion

intraperitoneal dexamethasone reduces postoperative pain after laparoscopic cholecystectomy.

Quiet wakefulness: The influence of intraperitoneal and intranasal oxytocin on sleep-wake behaviour and neurophysiology in rats

STUDY OBJECTIVES

Exogenous administration of the neuropeptide oxytocin exerts diverse effects on various neurobehavioural processes, including sleep and wakefulness. Since oxytocin can enhance attention to social and fear-related environmental cues, it should promote arousal and wakefulness. However, as oxytocin can attenuate stress, reduce activity, and elicit anxiolysis, oxytocin might also prime the brain for rest and promote sleep. At present, little research has comprehensively characterised the neuropsychopharmacology of oxytocin-induced effects on sleep-wake behaviour and no reconciliation of these two competing hypotheses has been proposed.

METHODS

This study explored the effects of oxytocin on sleep-wake outcomes using radiotelemetry-based polysomnography in adult male and female Wistar rats. Oxytocin was administered via intraperitoneal (i.p.; 0.1, 0.3 and 1 mg·kg -1) and intranasal (i.n.; 0.06, 1, 3 mg·kg -1) routes. Caffeine (i.p. and i.n.; 10 mg·kg -1) was administered as a wake-promoting positive control. To ascertain mechanism of action, pre-treatment experiments with the oxytocin receptor (OXTR) antagonist L-368,899 (i.p.; 5 mg·kg -1) followed by oxytocin (i.p.; 1 mg·kg -1) were also conducted.

RESULTS

In both male and female rats, i.p. oxytocin promoted quiet wakefulness at the cost of suppressing active wakefulness, NREM and REM sleep. Several i.p. oxytocin-induced sleep-wake effects were mediated by OXTR binding. In contrast, i.n. oxytocin did not alter most sleep-wake outcomes at any dose tested. Both i.p. and i.n. caffeine demonstrated wake-promoting effects.

CONCLUSIONS

These findings help reconcile competing hypotheses of oxytocin-induced effects on sleep-wake behaviour: i.p. oxytocin promotes quiet wakefulness-a state of restful environmental awareness compatible with both oxytocin's anxiolytic effects and its enhancement of processing complex stimuli.

Efficacy of Intraperitoneal 0.2% Ropivacaine With Dexmedetomidine Versus 0.2% Ropivacaine With Ketamine in Laparoscopic Surgeries: A Randomized Controlled Trial

BACKGROUND

Effective pain management modalities are the armamentarium for enhanced recovery in laparoscopic surgeries. Intraperitoneal instillation of local anaesthetics with adjuvants is advantageous in minimizing pain. So, we designed this study with the aim to compare the analgesic effectiveness of intraperitoneal ropivacaine with adjuvants like dexmedetomidine versus ketamine for postoperative analgesia.

OBJECTIVE

 The objective of this study is to assess the total duration of analgesia and total rescue analgesic dose requirements in the first 24 hours postoperatively.

MATERIALS AND METHODS

A total of 105 consenting patients for elective laparoscopic surgeries were enrolled and divided into three groups by computer-generated randomization as follows: Group 1: 30 ml of 0.2% ropivacaine with ketamine 0.5 mg/kg diluted to 1 ml; Group 2: 30 ml of 0.2% ropivacaine with dexmedetomidine 0.5 mcg/kg diluted to 1 ml; Group 3: 30 ml of 0.2% ropivacaine with 1 ml of normal saline. The postoperative visual analogue scale (VAS) score, total duration of analgesia, and total analgesic dose were calculated and compared among the three groups.

RESULTS

The postoperative analgesic duration after intraperitoneal instillation of Group 2 was longer as compared to Group 1. The total analgesic requirement was lower in Group 2 as compared to Group 1, and the p-value was significant (p ≤ 0.001) for both parameters. Demographic parameters and VAS scores among the three groups were not statistically significant.

CONCLUSION

We conclude that intraperitoneal instillation of local anaesthetics with adjuvants is effective for postoperative analgesia in laparoscopic surgeries, and ropivacaine 0.2% with dexmedetomidine 0.5 mcg/kg is more effective when compared to ropivacaine 0.2% with ketamine 0.5 mg/kg.

Effects of Chronically Exogenous Oxytocin on Ovary and Uterus: A Comparison of Intraperitoneal and Intranasal Administration

Oxytocin (OT) has been studied as a therapeutic neuropeptide in various diseases, but its effect on the ovary and uterus is not fully known. This study investigates the effects of intranasal and intraperitoneal OT administration on ovaries and uterus in rats. Four experimental groups were created using 7-week-old Sprague Dawley-type female rats: Control (Ctrl), oxytocin-intraperitoneal (0.1µg/day) (OT-IP), oxytocin-intranasal (0.05µg/day) (OT-IN1), and oxytocin-intranasal (0.1µg/day) (OT-IN2). The blood, the ovarian, and the uterus were collected at the end of the 28th day of OT administration. Afterward, histological and biochemical analyses were performed. We observed that the Graaf follicles were higher in both OT-IN2 and OT-IP groups compared to the Ctrl group. Moreover, the corpus luteum was increased only in the OT-IN2 group. Ki-67, CD31, VEGF, and TGF-ß immunostaining showed no significant change in the ovary. In contrast, Ki-67, VEGF, and OTR expressions demonstrated significant alterations in the uterus. Furthermore, TGF-ß immunohistochemistry and the histopathologic score did not reveal the statistical change in the uterus. Serum hormone levels showed that the anti-Müllerian hormone increased in all OT groups vs. the Ctrl. OT-IP showed an increment of follicle-stimulating hormone and estradiol decrement. There was a decrease in serum E2 levels, although the Graafian follicle number increased in OT-IP groups compared to the Ctrl group. However, luteinizing hormone, gonadotropin-releasing hormone, progesterone, testosterone, OT levels, and oxidative stress index did not reveal any statistical difference. Accordingly, the intranasal route may have beneficial effects compared to the intraperitoneal route regarding exogenous OT administration-related studies. In conclusion, we reported that exogenous OT increases the follicle reserve and may cause histological changes in the reproductive system of female rats.

Experimental Chemotherapy-Induced Mucositis: A Scoping Review Guiding the Design of Suitable Preclinical Models

Mucositis is a common and most debilitating complication associated with the cytotoxicity of chemotherapy. The condition affects the entire alimentary canal from the mouth to the anus and has a significant clinical and economic impact. Although oral and intestinal mucositis can occur concurrently in the same individual, these conditions are often studied independently using organ-specific models that do not mimic human disease. Hence, the purpose of this scoping review was to provide a comprehensive yet systematic overview of the animal models that are utilised in the study of chemotherapy-induced mucositis. A search of PubMed/MEDLINE and Scopus databases was conducted to identify all relevant studies. Multiple phases of filtering were conducted, including deduplication, title/abstract screening, full-text screening, and data extraction. Studies were reported according to the updated Preferred Reporting Items for Systematic reviews and Meta-Analyses Extension for Scoping Reviews (PRISMA-ScR) guidelines. An inter-rater reliability test was conducted using Cohen's Kappa score. After title, abstract, and full-text screening, 251 articles met the inclusion criteria. Seven articles investigated both chemotherapy-induced intestinal and oral mucositis, 198 articles investigated chemotherapy-induced intestinal mucositis, and 46 studies investigated chemotherapy-induced oral mucositis. Among a total of 205 articles on chemotherapy-induced intestinal mucositis, 103 utilised 5-fluorouracil, 34 irinotecan, 16 platinum-based drugs, 33 methotrexate, and 32 other chemotherapeutic agents. Thirteen articles reported the use of a combination of 5-fluorouracil, irinotecan, platinum-based drugs, or methotrexate to induce intestinal mucositis. Among a total of 53 articles on chemotherapy-induced oral mucositis, 50 utilised 5-fluorouracil, 2 irinotecan, 2 methotrexate, 1 topotecan and 1 with other chemotherapeutic drugs. Three articles used a combination of these drugs to induce oral mucositis. Various animal models such as mice, rats, hamsters, piglets, rabbits, and zebrafish were used. The chemotherapeutic agents were introduced at various dosages via three routes of administration. Animals were mainly mice and rats. Unlike intestinal mucositis, most oral mucositis models combined mechanical or chemical irritation with chemotherapy. In conclusion, this extensive assessment of the literature revealed that there was a large variation among studies that reproduce oral and intestinal mucositis in animals. To assist with the design of a suitable preclinical model of chemotherapy-induced alimentary tract mucositis, animal types, routes of administration, dosages, and types of drugs were reported in this study. Further research is required to define an optimal protocol that improves the translatability of findings to humans.

Evaluating the concept of gas‑based intraperitoneal hyperthermia beyond 43˚C in the treatment of peritoneal metastasis: A pilot study

While hyperthermic intraperitoneal applications have demonstrated high efficacy in treating peritoneal metastases (PM), these applications are limited to temperatures of 41-43˚C to prevent a harmful increase in core temperature. However, since gaseous substances display low specific heat capacities, gas-based hyperthermia could potentially increase surface temperatures without affecting the body's core temperature. To the best of our knowledge, the present study is the first to explore the in vivo feasibility of gas-based hyperthermia via spatial and time-based distribution. In the present study, a temperature-isolated, abdominal box model was created with fresh peritoneal tissue exposed to continuous high-volume airflow temperatures ranging between 47 and 69˚C. Heat conduction within the peritoneal tissues was measured using temperature microsensors. Temperature build-up at different time points during the procedure was calculated and the safest option to perform gas-based intraperitoneal hyperthermia beyond 43˚C was identified using an in vivo swine model. In subsequent experiments, viability and cytotoxicity of HT-29 colon cancer cells were measured following short-term hyperthermia. The present study demonstrated that the application of gas-based intraperitoneal hyperthermia with temperatures up to 50˚C is possible without increasing the core temperature to harmful levels. Gas-based intraperitoneal hyperthermia can induce a histological reaction on the peritoneal surface, and it can also result in decreased viability and increased cytotoxicity of HT-29 cells. The concept of extreme hyperthermia may be of great clinical importance as it could significantly increase local cytotoxicity in PM without increasing the body's core temperature. Further studies are required to investigate the benefits, as well as the restrictions, of this novel concept.

Safety, feasibility, and application of intraperitoneal gas-based hyperthermia beyond 43°C in the treatment of peritoneal metastasis: An in-vivo pilot study

BACKGROUND

43°Celsius (C) is currently the highest temperature used in the treatment of peritoneal metastasis (PM). Despite sufficient data on water- based hyperthermic solutions in PM treatment, there is currently no information on gas-based hyperthermia extending beyond 43°C. This study is the first to provide in-vivo data on different organ systems during and after intraperitoneal gas-based hyperthermia beyond 43°C. The aim of this study is to explore in-vivo feasibility, safety, and efficacy of this novel concept from a biological perspective.

METHODS

For this study, three swine were subjected to laparoscopy and subsequent gas-based intraperitoneal hyperthermia at 48°, 49° and 50°C under a high-flow air stream. Intraoperative data from multiple temperature sensors were analysed. Additionally, intraoperative anaesthesiologic and gasometrical data was analysed. Postoperatively, swine were monitored for one week and laboratory work-up was performed on postoperative days 1, 3 and 7.

RESULTS

During gas-based intraperitoneal hyperthermia, anesthesiologic parameters did not exhibit critical values. No intra- or postoperative complications were observed. Distinct temperature measurements on the skin, cystohepatic triangle and esophagus did not display any temperature increase. Postoperative laboratory workup did not show any changes in hemoglobin, white blood cell count, platelets, or kidney function.

DISCUSSION

Based on our data, there are no safety concerns for the application of gas-based hyperthermia between 48 - 50°C. In fact, no critical systemic temperature increase was observed. With respect to possible limitations, further in-vivo studies are required to evaluate whether gas-based intraperitoneal hyperthermia may be a therapeutic option for PM patients.

Good outcomes after pediatric intraperitoneal kidney transplant

BACKGROUND

Kidney transplantation in small children is technically challenging. Consideration of whether to use intraperitoneal versus extraperitoneal placement of the graft depends on patient size, clinical history, anatomy, and surgical preference. We report a large single-center experience of intraperitoneal kidney transplantation and their outcomes.

METHODS

We conducted a retrospective review of pediatric patients who underwent kidney transplantation from April 2011 to March 2018 at a single large volume center. We identified those with intraperitoneal placement and assessed their outcomes, including graft and patient survival, rejection episodes, and surgical or non-surgical complications.

RESULTS

Forty-six of 168 pediatric kidney transplants (27%) were placed intraperitoneally in children mean age 5.5 ± 2.3 years (range 1.6-10 years) with median body weight 18.2 ± 5 kg (range 11.4-28.6 kg) during the study period. Two patients (4%) had vascular complications; 10 (22%) had urologic complications requiring intervention; all retained graft function. Thirteen patients (28%) had prolonged post-operative ileus. Eight (17%) patients had rejection episodes ≤6 months post-transplant. Only one case resulted in graft loss and was associated with recurrent focal segmental glomerular sclerosis (FSGS). Two patients (4%) had chronic rejection and subsequent graft loss by 5-year follow-up. At 7-year follow-up, graft survival was 93% and patient survival was 98%.

CONCLUSIONS

The intraperitoneal approach offers access to the great vessels, which allows greater inflow and outflow and more abdominal capacity for an adult donor kidney, which is beneficial in very small patients. Risk of graft failure and surgical complications were not increased when compared to other published data on pediatric kidney transplants.

Testing oxygenated microbubbles via intraperitoneal and intrathoracic routes on a large pig model of LPS-induced acute respiratory distress syndrome

With a mortality rate of 46% before the onset of COVID-19, acute respiratory distress syndrome (ARDS) affected 200,000 people in the US, causing 75,000 deaths. Mortality rates in COVID-19 ARDS patients are currently at 39%. Extrapulmonary support for ARDS aims to supplement mechanical ventilation by providing life-sustaining oxygen to the patient. A new rapid-onset, human-sized pig ARDS model in a porcine intensive care unit (ICU) was developed. The pigs were nebulized intratracheally with a high dose (4 mg/kg) of the endotoxin lipopolysaccharide (LPS) over a 2 h duration to induce rapid-onset moderate-to-severe ARDS. They were then catheterized to monitor vitals and to evaluate the therapeutic effect of oxygenated microbubble (OMB) therapy delivered by intrathoracic (IT) or intraperitoneal (IP) administration. Post-LPS administration, the PaO2 value dropped below 70 mmHg, the PaO2 /FiO2 ratio dropped below 200 mmHg, and the heart rate increased, indicating rapidly developing (within 4 h) moderate-to-severe ARDS with tachycardia. The SpO2 and PaO2 of these LPS-injured pigs did not show significant improvement after OMB administration, as they did in our previous studies of the therapy on small animal models of ARDS injury. Furthermore, pigs receiving OMB or saline infusions had slightly lower survival than their ARDS counterparts. The OMB administration did not induce a statistically significant or clinically relevant therapeutic effect in this model; instead, both saline and OMB infusion appeared to lower survival rates slightly. This result is significant because it contradicts positive results from our previous small animal studies and places a limit on the efficacy of such treatments for larger animals under more severe respiratory distress. While OMB did not prove efficacious in this rapid-onset ARDS pig model, it may retain potential as a novel therapy for the usual presentation of ARDS in humans, which develops and progresses over days to weeks.

Development and Characterization of a Luciferase Labeled, Syngeneic Murine Model of Ovarian Cancer

Despite advances in surgery and targeted therapies, the prognosis for women with high-grade serous ovarian cancer remains poor. Moreover, unlike other cancers, immunotherapy has minimally impacted outcomes in patients with ovarian cancer. Progress in this regard has been hindered by the lack of relevant syngeneic ovarian cancer models to study tumor immunity and evaluate immunotherapies. To address this problem, we developed a luciferase labeled murine model of high-grade serous ovarian cancer, STOSE.M1 luc. We defined its growth characteristics, immune cell repertoire, and response to anti PD-L1 immunotherapy. As with human ovarian cancer, we demonstrated that this model is poorly sensitive to immune checkpoint modulators. By developing the STOSE.M1 luc model, it will be possible to probe the mechanisms underlying resistance to immunotherapies and evaluate new therapeutic approaches to treat ovarian cancer.

Biodistribution and Radiation Dosimetry of Intraperitoneally Administered 124I-Omburtamab in Patients with Desmoplastic Small Round Cell Tumors

The aim of this study was to assess the pharmacokinetics, biodistribution, and radiation dosimetry of ¹²⁴I-omburtamab administered intraperitoneally in patients with desmoplastic small round cell tumor. Methods: Eligible patients diagnosed with desmoplastic small round cell tumor with peritoneal involvement were enrolled in a phase I trial of intraperitoneal radioimmunotherapy with ¹³¹I-omburtamab. After thyroid blockade and before radioimmunotherapy, patients received approximately 74 MBq of ¹²⁴I-omburtamab intraperitoneally. Five serial PET/CT scans were obtained up to 144 h after injection. Multiple blood samples were obtained up to 120 h after injection. Organ-absorbed doses were calculated with OLINDA/EXM. Results: Thirty-one patients were studied. Blood pharmacokinetics exhibited a biphasic pattern consisting of an initial rising phase with a median half-time (±SD) of 23 ± 15 h and a subsequent falling phase with a median half-time of 56 ± 34 h. Peritoneal distribution was heterogeneous and diffuse in most patients. Self-dose to the peritoneal cavity was 0.58 ± 0.19 mGy/MBq. Systemic distribution and activity in major organs were low. The median absorbed doses were 0.72 ± 0.23 mGy/MBq for liver, 0.48 ± 0.17 mGy/MBq for spleen, and 0.57 ± 0.12 mGy/MBq for kidneys. The mean effective dose was 0.31 ± 0.10 mSv/MBq. Whole-body and peritoneal cavity biologic half-times were 45 ± 9 and 24 ± 5 h, respectively. Conclusion: PET/CT imaging with intraperitoneally administered ¹²⁴I-omburtamab enables assessment of intraperitoneal distribution and estimation of absorbed dose to peritoneal space and normal organs before therapy.

In Vivo Partial Oxygen Pressure Assessment in Subcutaneous and Intraperitoneal Sites Using Imaging of Solid Oxygen Probe

The purpose of this study was to assess the natural partial oxygen pressure (pO₂) of subcutaneous (SC) and intraperitoneal (IP) sites in mice to determine their relative suitability as sites for placement of implants. The pO₂ measurements were performed using oxygen imaging of solid probes using lithium phthalocyanine (LiPc) as the oxygen sensitive material. LiPc is a water-insoluble crystalline probe whose spin-lattice and spin-spin relaxation rates (R₁ and R₂) are sensitive to the local oxygen concentration. To facilitate direct in vivo oxygen imaging, we prepared a solid probe containing encapsulated LiPc crystals in polydimethylsiloxane (PDMS), an oxygen-permeable and bioinert polymer. Although LiPc-PDMS or similar probes have been used in repeated spectroscopic or average oxygen measurements using continuous wave electron paramagnetic resonance (EPR) since the late 1990s and now have advanced to clinical applications, they have not been used for pulse EPR oxygen imaging. One LiPc-PDMS probe of 2 mm diameter and 10 mm length was implanted in SC or IP sites (left or right side) in each animal. The pO₂ imaging of implanted LiPc-PDMS probes was performed weekly for 6 weeks using O2M preclinical 25 mT oxygen imager, JIVA-25™, using the pulse inversion recovery electron spin echo method. At week 6, the probes were recovered, and histological examinations were performed. We report in this study, first-ever solid probe oxygen imaging of implanted devices and pO₂ assessment of SC and IP sites.

Stability and compatibility of antibiotics in peritoneal dialysis solutions

Intraperitoneal (IP) administration of antibiotics is a preferred treatment of peritoneal dialysis (PD)-related peritonitis. Given the treatment duration of up to 2-3 weeks, it is important that robust data on antibiotic stability and compatibility are available to achieve notable treatment success. This article provides a comprehensive review of recent stability and compatibility studies pertaining to a wide range of antibiotics admixed in various PD solutions.

Neonatal Piglet Temperature Changes: Effect of Intraperitoneal Warm Saline Injection

Piglets are poor at thermoregulation immediately following birth and take up to 24 h to recover from their initial temperature drop. The present study aimed to determine if providing piglets with a 15 mL intraperitoneal injection of warm (45 °C) saline at birth would improve their internal temperature recovery to 24 h of age, and how the treatment interacted with birth weight (BWC = 1; ≤0.80 kg, BWC = 2; 0.81 kg to 1.10 kg, and BWC = 3; >1.10 kg), rectal temperature at 1.5 h (RC = 1; ≤32.0 °C, RC = 2; 32.10 °C to 35.0 °C, and RC = 3; ≥35.10 °C), and colostrum intake (CI = 1; <200 g and CI = 2, ≥200 g) to affect preweaning survival. Treated BWC1 piglets had improved rectal temperatures from 2 to 24 h. BWC3 piglets who consumed insufficient colostrum also had improved rectal temperature between 1 and 24 h post-birth. Colostrum intake was improved with saline injection in BWC2 piglets of RC1 and RC3 (p < 0.001) and BWC3-RC3 piglets (p < 0.001). Treated BWC1 improved survival to 20 d (p < 0.001). Irrespective of BWC, piglets from all RC had greater survival when injected with saline. The greatest difference was for piglets in RC1, likely due to all BWC1 piglets falling within this category. The results suggest that an intraperitoneal injection of warmed saline is an effective way to improve piglet temperature recovery to 24 h, colostrum intake, and survival in low-birth-weight piglets. These findings will be helpful for producers who have large numbers of low-birth-weight piglets born and are able to provide individual care.

Late renal allograft torsion in a pediatric transplant recipient

BACKGROUND

Kidney allograft torsion is a rare complication of kidney transplant that can lead to allograft loss from prolonged ischemia if not quickly corrected with detorsion and nephropexy. We report a case of late intraperitoneal renal allograft torsion in a pediatric transplant recipient.

CASE REPORT

The patient is a 7-year-old male with a history of end-stage renal disease secondary to renal dysplasia in the setting of bilateral high-grade vesicoureteral reflux. He underwent bilateral native nephrectomies for recurrent pyelonephritis and right ureteral kink with urinary tract obstruction. Torsion occurred 3 years after transplant in the setting of one day of emesis, loose stool, severe abdominal pain, and decreased urine output. Diagnosis of transplant torsion was suspected on non-contrast CT scan done after transplant Doppler ultrasound showed no flow to the allograft. The CT scan showed that the kidney had been medialized and renal hilum was flipped from the expected orientation. The patient required a transplant nephrectomy.

CONCLUSIONS

Renal transplant torsion is a rare event but should be suspected in any renal transplant recipient with acute onset of abdominal pain, acute kidney injury, and decreased urine output, regardless of length of time from transplantation. Patients suspected to have renal torsion should be evaluated emergently with a transplant ultrasound Doppler.

Practice variations in antibiotic administration for the management of peritonitis in patients on automated peritoneal dialysis in Australia and New Zealand

In the absence of guidelines on the management of peritoneal dialysis (PD)-associated peritonitis in patients on automated peritoneal dialysis (APD), variations in clinical practice potentially exist between PD units that could affect clinical outcomes. This study aimed to document the current practices of treating PD-associated peritonitis in patients on APD across Australia and New Zealand and the reasons for practice variations using a cross-sectional online survey. Of the 62 PD units, 34 medical leads (55%) responded to the survey. When treating APD-associated peritonitis, 21 units (62%) continued patients on APD and administered intraperitoneal (IP) antibiotics in manual daytime exchanges; of these, 17 (81%) considered allowing at least 6 h dwell time for adequate absorption of the IP antibiotics as an important reason for adding manual daytime exchange. Nine units (26%) temporarily switched patients from APD to continuous ambulatory peritoneal dialysis (CAPD); of these, five (55%) reported a lack of pharmacokinetic (PK) data for IP antibiotics in APD, four (44%) reported a shortage of APD-trained nursing staff to perform APD exchanges during hospitalisation and three (33%) reported inadequate time for absorption of IP antibiotics on APD as important reasons for their practice. Four units (12%) continued patients on APD and administered IP antibiotics during APD exchanges; of these, three (75%) believed that PK data available in CAPD could be extrapolated to APD. This study demonstrates wide variations in the management of APD-associated peritonitis in Australia and New Zealand; it points towards the lack of PK on antibiotics used to treat peritonitis as an important reason underpinning practice variations.

Pharmacokinetics, tissue distribution and peritoneal retention of Ag2S quantum dots following intraperitoneal administration to mice

OBJECTIVES

To investigate the pharmacokinetics, biodistribution and peritoneal retention of Ag2S quantum dots (Qds) after intraperitoneal (IP) injection into mice and to compare the results with those reported for the intravenous (IV) injection of these particles.

METHODS

Ag2S Qds was prepared by a simple one-step co-precipitation method and was injected intraperitoneally into mice. Six animals were sacrificed at predetermined time points, and blood, peritoneal content and tissue samples were collected. Ag concentration that represents the concentration of Qds was analysed by atomic absorption spectrophotometry.

KEY FINDINGS

Detectability of Qds in the peritoneal sample up to 2 h indicated that, compared with small drug molecules, the absorption of Ag2S Qds from the peritoneal cavity occurred at a slower rate. The AUC tissue/AUC blood ratio in the liver and intestine after IP injection (0.55 and 0.98, respectively) was considerably lower than those for the bolus injection (217 and 94, respectively), while this ratio in the spleen and lungs was markedly higher than the IV route.

CONCLUSIONS

Overall, the obtained results suggest that IP injection of Ag2S Qds could be more effective for drug delivery to/imaging of the spleen and lungs, whereas the IV injection for the drug delivery to/imaging of the liver and intestine.

Evaluation of intraperitoneal administration of morphine on post-operative pain management after ovariohysterectomy in dogs

The present prospective randomized experimental study was designed to assess pain control with intraperitoneal morphine following ovariohysterectomy in dogs. A group of 12 mixed breed female dogs, aged 1-2 years, weighing 19.95 ± 0.95 kg were included. Forty minutes after sedation with 0.05 mg/kg intramuscular acepromazine 1%, anaesthesia was induced with propofol (4 mg/kg). The dogs were connected to the inhalation anaesthesia circuit using isoflurane. Ovariohysterectomy was performed, and before the closure of linea alba, the animals received intraperitoneal morphine (0.5 mg/kg) (in group M) and saline (0.2 ml/kg) (in group S). No significant difference was detected in total protein and glucose levels between the groups, while the cortisol level in group M was significantly lower than group S 1, 3 and 6 h after surgery. Furthermore, the comparison of the rectal temperature, heart rates and respiratory rates showed no major differences. Additionally, no significant alterations were detected between the groups considering the changes in the pain scores with simple descriptive score, Glasgow, University of Melbourne pain scale, sedation status and Sammarco methods. Finally, three cases in group S and two cases in group M were given an intramuscular analgesic rescue dose of morphine. Although a significant decline was observed in cortisol levels following intraperitoneal morphine administration, there were no beneficial changes in the efficiency of post-operative analgesia in status and clinical signs compared to the control group. Further studies are required to investigate intraperitoneal morphine effectiveness in post-operative pain management.

Acute intraperitoneal rupture of hydatid cysts of the liver: Case series

Hydatid cyst is a parasitic infection caused mainly by Echinococcus granulosus, which is generally considered benign. However, the hepatic hydatid cyst rupture in the abdominal cavity is a life-threatening incident that requires urgent and multidisciplinary management (emergency physicians, radiologists, anesthetists, and surgeons). This study describes clinical and paraclinical liver hydatid cyst rupture in the peritoneal cavity and details the appropriate treatment.A retrospective review of clinical records of patients hospitalized in Jendouba Hospital for liver hydatid cyst was performed over 8 years, from January 1, 2012 to December 31, 2019. Fifteen cases of liver hydatid cyst complicated with acute rupture into the abdominal cavity were collected out of 625 hydatid liver cysts. All patients underwent emergency laparotomy allowing conservative unroofing procedure associated with peritoneal lavage and external drainage combined with necessary intensive care measures. Clinical features, therapeutic procedures' details as well as postoperative outcomes are reported. Statistical analysis was performed using the Statistical Package for the Social Sciences for Windows version 20.There were 9 men and 6 women. Patients' age ranged from 14 to 59 years, with an average of 38 years. Two patients were admitted with abdominal trauma. Acute abdominal pain was the most common complaint. Only 1 patient had an anaphylactic shock. Abdominal ultrasonography and computed tomography scan showed discontinuous cyst wall associated to intraperitoneal fluid in all cases. Intraoperatively, the intraperitoneal effusion was clear in 13 cases and purulent in 2. All patients underwent unroofing procedures associated with intra-operative peritoneal lavage and external drainage. The mean hospital stay was 6.11 days, and the mean follow-up was 19 months. No case of recurrence was reported among the patients.In endemic areas, rupture of a hepatic hydatid cyst in the abdominal cavity should be considered in every case of acute abdominal pain, especially if associated with anaphylaxis signs. Early management starting in the emergency room is needed to ensure good outcome.

A Modified Intraperitoneal Chemotherapy Regimen for Ovarian Cancer: Technique and Treatment Outcomes

Simple Summary

To overcome the limitations of intraperitoneal chemotherapy (IP), which include a low completion rate and port-related toxicities, we modified three institutional procedures concerning IP chemotherapy in patients with ovarian cancer: (i) insertion of an IP port in a neutral abdominal position, (ii) daily irrigation of the peritoneal cavity with warmed dextrose fluid (5%) for IP port patency and to prevent adhesion, and (iii) intravenous infusion of cisplatin on Day 2 after left colonic surgery. Among patients who underwent left colonic surgery, including low anterior resection, 27 were investigated to identify the rate of completion of six planned cycles and the feasibility of IP chemotherapy. With modifications in IP chemotherapy, the completion rate improved even after patients underwent left colonic surgery during cytoreduction with enhanced feasibility.

Abstract

This study aimed to investigate treatment outcomes concerning three institutional modifications to intraperitoneal (IP) chemotherapy for patients with ovarian cancer. The medical records of 27 patients treated with IP chemotherapy were retrospectively reviewed. All patients had three IP chemotherapy institutional modifications; modified Gynecologic Oncology Group 172 regimen was used for the chemotherapy regimen. With institutional modifications, 63.0% (17/27) completed all six cycles of IP chemotherapy. Of the 17 and 10 patients with primary and recurrent ovarian cancer, respectively, 55.6% (15/27) underwent left colonic surgery, including low anterior resection. In patients with primary ovarian cancer, the IP chemotherapy completion rate was 76.5% (13/17). In patients with and without left colonic surgery, the IP chemotherapy completion rates were 53.3% (8/15) and 75.0% (9/12), respectively. No complications related to left colonic surgery during IP chemotherapy were identified. The most frequent grade 3–4 toxicities were gastrointestinal toxicities (33.3%) and neutropenia (29.6%). The median progression-free survival was 19.5 months in all patients and 25.2 months in patients with primary ovarian cancer. Three institutional modifications to IP chemotherapy increased the completion rate for planned IP chemotherapy, even after left colonic surgery. Further studies involving a larger study cohort are required to confirm survival outcomes using these modifications.

Calcium Carbonate Microparticles as Carriers of 224Ra: Impact of Specific Activity in Mice with Intraperitoneal Ovarian Cancer

BACKGROUND

Patients with advanced-stage ovarian cancer face a poor prognosis because of recurrent peritoneal cavity metastases following surgery and chemotherapy. Alpha-emitters may enable the efficient treatment of such disseminated diseases because of their short range and highly energetic radiation. Radium-224 is a candidate α-emitter due to its convenient 3.6-day half-life, with more than 90% of the decay energy originating from α-particles. However, its inherent skeletal accumulation must be overcome to facilitate intraperitoneal delivery of the radiation dose. Therefore, ²²⁴Ra-labeled CaCO₃ microparticles have been developed.

OBJECTIVE

The antitumor effect of CaCO₃ microparticles as a carrier for ²²⁴Ra was investigated, with an emphasis on the ratio of activity to mass dose of CaCO₃, that is, specific activity.

METHODS

Nude athymic mice were inoculated intraperitoneally with human ovarian cancer cells (ES-2) and treated with a single intraperitoneal injection of ²²⁴Ra-labeled CaCO₃ microparticles with varying combinations of mass and activity dose, or cationic ²²⁴Ra in solution. Survival and ascites volume at sacrifice were evaluated.

RESULTS

Significant therapeutic effect was achieved for all tested specific activities ranging from 0.4 to 4.6 kBq/mg. Although treatment with a mean activity dose of 1305 kBq/kg of cationic ²²⁴Ra prolonged the survival compared with the control, equivalent median survival could be achieved with ²²⁴Ra-labeled microparticles with a mean dose of only 420 kBq/kg. The best outcome was achieved with the highest specific activities (2.6 and 4.6 kBq/mg).

CONCLUSION

Radium-224-labeled CaCO₃ microparticles present a promising therapy against cancer dissemination in body cavities.

Endothelial Nox2 Limits Systemic Inflammation and Hypotension in Endotoxemia by Controlling Expression of Toll-Like Receptor 4

ABSTRACT

Leukocyte Nox2 is recognized to have a fundamental microbicidal function in sepsis but the specific role of Nox2 in endothelial cells (EC) remains poorly elucidated. Here, we tested the hypothesis that endothelial Nox2 participates in the pathogenesis of systemic inflammation and hypotension induced by LPS. LPS was injected intravenously in mice with Tie2-targeted deficiency or transgenic overexpression of Nox2. Mice with Tie2-targeted Nox2 deficiency had increased circulating levels of TNF-α, enhanced numbers of neutrophils trapped in lungs, and aggravated hypotension after LPS injection, as compared to control LPS-injected animals. In contrast, Tie2-driven Nox2 overexpression attenuated inflammation and prevented the hypotension induced by LPS. Because Tie2-Cre targets both EC and myeloid cells we generated bone marrow chimeric mice with Nox2 deletion restricted to leukocytes or ECs. Mice deficient in Nox2 either in leukocytes or ECs had reduced LPS-induced neutrophil trapping in the lungs and lower plasma TNF-α levels as compared to control LPS-injected mice. However, the pronounced hypotensive response to LPS was present only in mice with EC-specific Nox2 deletion. Experiments in vitro with human vein or aortic endothelial cells (HUVEC and HAEC, respectively) treated with LPS revealed that EC Nox2 controls NF-κB activation and the transcription of toll-like receptor 4 (TLR4), which is the recognition receptor for LPS. In conclusion, these results suggest that endothelial Nox2 limits NF-κB activation and TLR4 expression, which in turn attenuates the severity of hypotension and systemic inflammation induced by LPS.

Varying clinical presentations of umbilical venous catheter extravasation: A case series

Umbilical venous catheter insertion is a common procedure in the neonatal units performed for rapid vascular access. Though relatively safe and easy to perform, suboptimal position of the catheter tip is frequently encountered and can lead to wide range of complications from venous thrombosis, catheter extravasation with extravasation of infusate to intraperitoneal or intrapericardial space, liver injury and cardiac arrhythmias. Identification of catheter extravasation may be difficult and often confused with catheter related infection or necrotising enterocolitis. We present a series of three cases of intraperitoneal extravasation of umbilical venous catheter in the premature neonate with widely varying presentation from subtle biochemical changes to critical clinical signs with rapid and progressive deterioration.

Hyperthermic Intraperitoneal Chemotherapy: A Critical Review

Simple Summary

Patients with cancer of the digestive system or ovarian cancer are at risk of developing peritoneal metastases (PM). In some patients with PM, surgery followed by intraperitoneal (IP) chemotherapy has emerged as a valid treatment option. The addition of hyperthermia is thought to further enhance the efficacy of IP chemotherapy. However, the results of recent clinical trials in large bowel cancer have put into question the use of hyperthermic intraperitoneal chemotherapy (HIPEC). Here, we review the rationale and current results of HIPEC for PM and propose a roadmap to further progress.

Abstract

With increasing awareness amongst physicians and improved radiological imaging techniques, the peritoneal cavity is increasingly recognized as an important metastatic site in various malignancies. Prognosis of these patients is usually poor as traditional treatment including surgical resection or systemic treatment is relatively ineffective. Intraperitoneal delivery of chemotherapeutic agents is thought to be an attractive alternative as this results in high tumor tissue concentrations with limited systemic exposure. The addition of hyperthermia aims to potentiate the anti-tumor effects of chemotherapy, resulting in the concept of heated intraperitoneal chemotherapy (HIPEC) for the treatment of peritoneal metastases as it was developed about 3 decades ago. With increasing experience, HIPEC has become a safe and accepted treatment offered in many centers around the world. However, standardization of the technique has been poor and results from clinical trials have been equivocal. As a result, the true value of HIPEC in the treatment of peritoneal metastases remains a matter of debate. The current review aims to provide a critical overview of the theoretical concept and preclinical and clinical study results, to outline areas of persisting uncertainty, and to propose a framework to better define the role of HIPEC in the treatment of peritoneal malignancies.

The functional morphology of the postpulmonary septum of the American alligator (Alligator mississippiensis)

The American alligator (Alligator mississippiensis) has a postpulmonary septum (PPS) that partitions the intracoelomic cavity. The PPS adheres to the capsule of the liver caudally and to the visceral pleura of the lung cranially; the ventrolateral portions of the PPS are invested with smooth muscle, the remainder is tendinous. Differential pressure transducers were used to record the intrathoracic (ITP) and intraperitoneal (IPP) pressures, and determine the transdiaphragmatic pressure (TDP). Each ventilatory pulse resulted in a pulse in ITP and a significantly lower pulse in IPP; meaning that a TDP was established, and that the pleural and peritoneal cavities were functionally isolated. The anesthetized alligators were tilted 30° head-up or head-down in order to displace the liver. Head-up rotations caused a significant increase in IPP, and a significant decrease in ITP (which became negative); head-down rotations produced the opposite effect. During these rotations, the PPS maintained opposite pressures (positive or negative) in the pleural and peritoneal cavities, and established TDPs greater than have been reported for some mammals. Two types of "breaths" were recorded during these experiments. The first was interpreted as a contraction of the diaphragmaticus muscle, which displaces the liver caudally; these breaths had the same effect as the head-up rotations. The second type of breath was interpreted as constriction of the thoracic and abdominal body walls; this type of breath produced pronounced, long-duration, roughly parallel, increases in ITP and IPP. The smooth muscle within the PPS is suggestive of higher-order adjustment or tuning of the PPS's tensile state.

Biodistribution of Transplanted Hematopoietic Precursor Cells Injected Through Different Administration Routes in Newborn Mice

Hematopoietic stem cell transplantation has been studied for several decades now, mostly as a treatment for malignancies and hematological diseases but also for genetic metabolic disorders. Since many diseases that could be potentially treated with this approach develop early in life, studies of cell transplantation in newborn mice are needed, especially for gene therapy protocols. However, the small size of pups restricts the possibilities for routes of administration, and those available are normally technically challenging. Our goal was to test different routes of administration of Lin^- cells in 2-day-old mice: intraperitoneal, intravenous through temporal vein (TV), and intravenous through retro-orbital (RO) sinus. Routes were evaluated by their easiness of execution and their influence in the biodistribution of cells in the short (48 h) and medium (30 days) term. In either 48 h or 30 days, all three routes presented similar results, with cells going mostly to bone marrow, liver, and spleen in roughly the same number. RO injection resulted in quick distribution of cells to the brain, suggesting better performance than the others. Rate of failure was higher for the TV route, which was also the hardest to execute, whereas the other two were considered easier. In conclusion, TV was the hardest to perform and all routes seemed to demonstrate similar results for cell biodistribution. In particular, the RO injection results in quicker biodistribution of cells to the brain, which is particularly important in the study of genetic metabolic disorders with a neurological component.

A Comparative Study on the Postoperative Analgesic Effects of the Intraperitoneal Instillation of Bupivacaine Versus Normal Saline Following Laparoscopic Cholecystectomy

Background Laparoscopic cholecystectomy is widely performed, and postoperative pain is an important factor in patient morbidity during recovery. Various modalities for postoperative pain relief have been proposed, with varying levels of success such as intravenous or intramuscular non-steroidal anti-inflammatory drugs (NSAIDs) and opioids, infiltration at the incision site with local anesthetics, intraperitoneal infiltration of local anesthetics, intraperitoneal infiltration of local anesthetics with adjuvants, regional anesthesia techniques such as epidurals and nerve blocks. The study was aimed to evaluate the efficacy of intraperitoneal instillation of bupivacaine and normal saline on postoperative analgesia, postoperative nausea, and vomiting after laparoscopic cholecystectomy. Methods This prospective, controlled, and randomized study included 60 American Society of Anesthesiologists (ASA) I and ASA II patients, aged 18-50 years, who were scheduled for laparoscopic cholecystectomy under general anesthesia. The patients were classified randomly into two groups with an equal number of participants: Group B received intraperitoneal instillation of 30 ml of plain bupivacaine 0.5% and Group N received 30 ml of normal saline. Postoperative pain was recorded using the visual analog scale (VAS) for 24 hours after surgery. Postoperative shoulder pain, nausea, vomiting, and the time taken to request rescue analgesia were noted. Results Patients receiving intraperitoneal bupivacaine showed a significant reduction in postoperative pain for the first six hours postoperatively (P = 0.04); moreover, the time taken to request rescue analgesia requirement was prolonged (P = 0.04). Side effects, such as nausea and vomiting, were similar between the two groups (P = 0.1 and p = 0.09, respectively) while shoulder pain was significantly lower in the bupivacaine group (P = 0.04). Conclusion Bupivacaine is effective in reducing postoperative pain, and it prolongs the requirement time for rescue analgesia. It also reduces the incidence of shoulder pain but does not decrease postoperative nausea and vomiting.

Efficient Treatment of Experimental Cerebral Malaria by an Artemisone-SMEDDS System: Impact of Application Route and Dosing Frequency

Artemisone (ART) has been successfully tested in vitro and in animal models against several diseases. However, its poor aqueous solubility and limited chemical stability are serious challenges. We developed a self-microemulsifying drug delivery system (SMEDDS) that overcomes these limitations. Here, we demonstrate the efficacy of this formulation against experimental cerebral malaria in mice and the impact of its administration using different routes (gavage, intranasal delivery, and parenteral injections) and frequency on the efficacy of the treatment. The minimal effective daily oral dose was 20 mg/kg. We found that splitting a dose of 20 mg/kg ART given every 24 h, by administering two doses of 10 mg/kg each every 12 h, was highly effective and gave far superior results compared to 20 mg/kg once daily. We obtained the best results with nasal treatment; oral treatment was ranked second, and the least effective route of administration was intraperitoneal injection. A complete cure of experimental cerebral malaria could be achieved through choosing the optimal route of application, dose, and dosing interval. Altogether, the developed formulation combines easy manufacturing with high stability and could be a successful and very versatile carrier for the delivery of ART in the treatment of human severe malaria.

Intravenous Administration is the Best Route of Mesenchymal Stem Cells Migration in Improving Liver Function Enzyme of Acute Liver Failure

BACKGROUND

Mesenchymal stem cells (MSCs) migrate and transmigrate to acute liver failure (ALF) area due to vascular endothelial growth factor (VEGF) stimulation as an attractant molecule then actively giving the paracrine signaling and or differentiating into primary hepatocytes, however the best route of MSCs transplanted to liver injury area remains unclear.

AIM

In this study we compare intravenous (IV) and intraperitoneal (IP) route of MSCs administration by analyzing serum glutamic pyruvic transaminase (SGPT), serum glutamic-oxaloacetic transaminase (SGOT) and bilirubin level as improvement markers of liver function and VEGF as attractant-proliferation molecule on days 2 and 5.

MATERIALS AND METHODS

Eighteen male Sprague-Dawley rats weighting 200 g were used in this study. They were divided in three study groups: vehicle control, IP and IV groups. The IV group was treated by MSCs at dose 1&times;106 by lateral tail vein injection and IP group received 1&times;106 MSCs via IP injection. The level of SGPT, SGOT and bilirubin were measured by an automatic analyzer, the VEGF level using enzyme-linked immunosorbent assay (ELISA), while the CD73 expression was evaluated using immunohistochemistry.

RESULTS

This study showed that IV injection of MSCs was more efficient for increasing liver function than IP treatment group that confirmed by the observed significant decrease in SGPT, SGOT and bilirubin level on days 2 and 5 (p&lt;0.001). This effect was most likely mediated by the significant increase of VEGF level (p&lt;0.05) on days 2 and 5.

CONCLUSION

Our result conclude that an IV administration of MSCs was more efficacious than the IP administration for liver injury regeneration.

Pharmacokinetics of culture-directed antibiotics for the treatment of peritonitis in automated peritoneal dialysis: A systematic narrative review

The objectives of this study were to provide a summary of the pharmacokinetic data of some intraperitoneal (IP) antibiotics that could be used for both empirical and culture-directed therapy, as per the ISPD recommendations, and examine factors to consider when using IP antibiotics for the management of automated peritoneal dialysis (APD)-associated peritonitis. A literature search of PubMed, EMBASE, Scopus, MEDLINE and Google Scholar for articles published between 1998 and 2020 was conducted. To be eligible, articles had to describe the use of antibiotics via the IP route in adult patients ≥18 years old on APD in the context of pharmacokinetic studies or case reports/series. Articles describing the use of IP antibiotics that had been recently reviewed (cefazolin, vancomycin, gentamicin and ceftazidime) or administered for non-APD-associated peritonitis were excluded. A total of 1119 articles were identified, of which 983 abstracts were screened. Seventy-three full-text articles were assessed for eligibility. Eight records were included in the final study. Three reports had pharmacokinetic data in patients on APD without peritonitis. Each of cefepime 15 mg/kg IP, meropenem 0.5 g IP and fosfomycin 4 g IP given in single doses achieved drug plasma concentrations above the minimum inhibitory concentration for treating the susceptible organisms. The remaining five records were case series or reports in patients on APD with peritonitis. While pharmacokinetic data support intermittent cefepime 15 mg/kg IP daily, only meropenem 0.5 g IP and fosfomycin 4 g IP are likely to be effective if given in APD exchanges with dwell times of 15 h. Higher doses may be required in APD with shorter dwell times. Information on therapeutic efficacy was derived from case reports/series in individual patients and without therapeutic drug monitoring. Until more pharmacokinetic data are available on these antibiotics, it would be prudent to shift patients who develop peritonitis on APD to continuous ambulatory peritoneal dialysis, where pharmacokinetic information is more readily available.

Intraperitoneal administration of lidocaine or tramadol alone or in combination on postoperative pain after ovariohysterectomy in dogs

The present prospective randomized experimental study aimed to assess the intraperitoneal (ip) administration of lidocaine or tramadol, alone or in combination, on postoperative pain management following ovariohysterectomy in dogs. Eighteen healthy female mixed‐breed dogs, aged 1–2 years, weighed 16.7 ± 3.8 kg, were used. Animals were sedated with acepromazine (0.1 mg/kg, intramuscular). Forty minutes later, anaesthesia was induced through intravenous titration with diazepam (0.5 mg/kg) and ketamine (10 mg/kg) and maintained with isoflurane 1.5%. Afterwards, ovariohysterectomy was performed, and prior to the closure of the linea alba, animals received lidocaine containing epinephrine (8.8 mg/kg, ip) in group L, tramadol (4 mg/kg, ip) in group T and lidocaine containing epinephrine (8.8 mg/kg, ip) plus tramadol (4 mg/kg, ip) in the LT group. Cortisol, vital signs and pain scoring systems were evaluated at different time points. Vital signs did not change among the groups. Cortisol level in the LT group significantly decreased compared to the L and T groups one, three and six hours after surgery. Pain scores also did not change among the groups based on Sammarco and Simple descriptive (SDS) scoring method. However, pain scores in the LT group were higher than the two other groups according to the University of Melbourne pain scale (UMPS) and the short form of Glasgow pain scale (CMPS‐SF). According to the obtained results, the combination of lidocaine and tramadol seemed to be able to provide better analgesia compared with their separate administration. Therefore, combined intraperitoneal administration of lidocaine (8.8 mg/kg) and tramadol (4 mg/kg) with a final volume of (0.2 ml/kg) following ovariohysterectomy is recommended.

An investigation of the effects of dexmedetomidine and fentanyl as an adjuvant to ropivacaine on pain scores and hemodynamic changes following laparoscopic cholecystectomy

Postoperative pain control is recognized as a challenging surgical issue receiving high priority in the healthcare system, and opioids are routinely prescribed for anesthesia and pain relief. This study aimed to investigate the effects of ropivacaine administered intraperitoneally alone or combined with dexmedetomidine or fentanyl on postoperative pain control following laparoscopic cholecystectomy. This randomized double-blind clinical trial recruited three equal-size block-randomized groups of patients (n = 138) scheduled for elective laparoscopic cholecystectomy at Valiasr Hospital, Arak, Iran, in 2019–2020 who received ropivacaine (40 mL/0.5%), ropivacaine (40 mL/0.5%) + dexmedetomidine (1 μg/kg), and ropivacaine (40 mL/0.5%) + fentanyl (1 μg/kg). No significant differences were observed among the three groups according to the vital signs (mean arterial pressure/heart-rate/oxygen saturation) in the study period and during surgery (P > 0.05). Lower pain was revealed in the ropivacaine + dexmedetomidine group (P = 0.001), with the lowest opioid dose in postoperative 24 hours (P = 0.001). Moreover, no clinically significant differences were observed in complications among the three groups (P = 0.483), and no patient developed ileus. Intraperitoneal ropivacaine administered with dexmedetomidine could relieve pain and reduce opioid use in postoperative 24 hours, without any complication and ileus. Therefore, intraperitoneal ropivacaine administered with dexmedetomidine is recommended for postoperative pain control in patients undergoing laparoscopic cholecystectomy. This study was approved by the Ethical Committee of Arak University of Medical Sciences (approval No. IR.ARAKMU.REC.1397.267) on December 30, 2018 and was registered in the Iranian Registry of Clinical Trials (No. IRCT 20141209020258N117) on July 13, 2019.

Establishment of a Mouse Ovarian Cancer and Peritoneal Metastasis Model to Study Intraperitoneal Chemotherapy

Simple Summary

Intraperitoneal chemotherapy (IPC) is a locoregional treatment option in patients with peritoneal metastases (PM). Small animal models are valuable research tools allowing for rapid, reproducible, and inexpensive study and optimization of different forms of IPC. Here, we present a mouse model of ovarian cancer-derived PM and demonstrate its suitability for various modes of IPC, including pressurized intraperitoneal chemotherapy (PIPAC) using a micro-nozzle for aerosolized drug delivery.

Abstract

Intraperitoneal chemotherapy (IPC) is a locoregional treatment option in patients with peritoneal metastases (PM). Here, we present an ovarian cancer (OC)-derived PM mouse model for the study of different forms of IPC. Xenograft cell proliferation (luciferase-transfected OVCAR3 and SKOV3 clones) and growth kinetics were assessed using PET scan, bioluminescence imaging (BLI), and histological tumor analysis. Liquid IPC was achieved by intraperitoneal injection with/without capnoperitoneum (6–7 mmHg). Pressurized intraperitoneal aerosol chemotherapy (PIPAC) was mimicked using an intratracheal drug aerosol administration system (micro-nozzle), which, as demonstrated by ex vivo granulometric analysis using laser diffraction spectrometry, produced a polydisperse, bimodal aerosol with a volume-weighted median diameter of (26.49 ± 2.76) µm. Distribution of Tc-99m-labeled doxorubicin in mice was characterized using SPECT and was dependent on the delivery mode and most homogeneous when the micro-nozzle was used. A total of 2 mg doxorubicin per kg body weight was determined to be the optimally effective and tolerable dose to achieve at least 50% tumor reduction. Repeated PIPAC (four times at seven-day-intervals) with doxorubicin in SKOV3-luc tumor-bearing mice resulted in halted tumor proliferation and tumor load reduced after the second round of PIPAC versus controls and the number of tumor nodules was significantly reduced (27.7 ± 9.5 vs. 57.3 ± 9.5; p = 0.0003). Thus, we established the first mouse model of OC PM for the study of IPC using a human xenograft with SKOV3 cells and an experimental IPC setup with a miniaturized nozzle. Repeated IPC was feasible and demonstrated time-dependent anti-tumor activity.

Intravenous Clonidine versus Intraperitoneal Clonidine for Postoperative Analgesia After Total Abdominal Hysterectomy: A Randomised Controlled Trial

Objective

This prospective randomised double-blind study was conducted to compare the effect of intravenous (IV) with intraperitoneal (IP) administration of clonidine with respect to analgesic efficacy and side effects.

Methods

A total of 60 American Society of Anaesthesiologists (ASA) physical status class I and II patients, aged 35–60 years, undergoing total abdominal hysterectomy, were randomly divided into 2 groups. Standard general anaesthesia technique was used. All the patients in group IV received 3 μg kg⁻¹ of IV clonidine after resection of the uterus along with 0.25% bupivacaine (20 mL intraperitoneally and 10 mL as wound infiltration), whereas patients in group IP received 10 mL of normal saline intravenously and 3 μg kg⁻¹ of clonidine mixed with 0.25% bupivacaine (20 mL intraperitoneally and 10 mL as wound infiltration). Postoperative analgesia was provided with IV diclofenac every 8 hours and IV fentanyl (1 μg kg⁻¹) on demand. Pain at rest, opioid consumption, level of sedation and severity of nausea were recorded for 24 hours. The heart rate (HR) and blood pressure (BP) were recorded at an interval of 15 minutes for 2 hours followed by routine hourly monitoring.

Results

Both the groups were found to be similar with respect to demography and ASA physical status. The maximum pain was felt at 6 hours in both the groups. The mean visual analogue scale score at 6 hours (p=0.47) was comparable. However, patients in group IV had significantly higher sedation (p<0.001) and nausea (p=0.013) scores on arrival at post-anaesthesia care unit along with a significant reduction in HR (p=0.001) and BP (p=0001) for the first 2 hours postoperatively.

Conclusion

Although IP clonidine is comparable with IV clonidine with respect to postoperative pain scores and supplementary opioid requirement, the side effects are significantly less with IP clonidine.

Idiopathic Spontaneous Intraperitoneal Hemorrhage due to Rupture of Short Gastric Artery Presenting as Massive Gastrointestinal Bleeding: A Rare Case Presentation and Literature Review

Idiopathic spontaneous intraperitoneal hemorrhage (ISIH) or abdominal apoplexy is due to the tear of an intra-abdominal visceral vessel spontaneously where no cause can be identified. It is an uncommon but potentially life-threatening condition that generally shows up as a diagnostic dilemma as well as is related to formidable mortality. Among all the reported cases, the extemporaneous tear of short gastric arteries is extremely rare, but it has never been reported to present with massive gastrointestinal bleeding. We report a rare instance of idiopathic spontaneous intraperitoneal hematoma eroding the stomach wall, causing massive gastrointestinal bleeding.

LOPH: a novel chemotherapeutic protocol for feline high-grade multicentric or mediastinal lymphoma, developed in an area endemic for feline leukemia virus

OBJECTIVES

The aim of this study was to establish the safety and efficacy of a novel multidrug lomustine-based chemotherapeutic protocol for cats with high-grade multicentric or mediastinal lymphoma, in an area endemic for feline leukemia virus (FeLV).

METHODS

This prospective study included owned cats, diagnosed (cytologically) with multicentric or mediastinal lymphoma and treated with the LOPH (lomustine, vincristine [Oncovin; Antibióticos do Brasil], prednisolone and hydroxydaunorubicin [doxorubicin]) protocol. A complete blood count was performed before every chemotherapy session and any significant abnormalities recorded as possible related toxicities. Median survival time (MST) and disease-free interval were estimated by Kaplan-Meier curves.

RESULTS

Twenty-one cats were included in this study. Nineteen (90.5%) tested positive for FeLV and were therefore considered to have persistent viremia. Complete response was reported in 81% (n = 17/21), while three had partial remission and one had no response. Seven cats finished the induction protocol within 20-31 weeks (23.1 ± 4.5; median 20) and all seven received a maintenance protocol. The MST (lymphoma-related survival) for the 21 cats was 214 days. The MST was 214 days for cats with mediastinal lymphoma (n = 13), but it was not reached for multicentric lymphoma (n = 8; P = 0.9). The MST of cats with persistent FeLV antigenemia was 171 days. Grade I anorexia and vomiting occurred in 19% of the cats (n = 4/21). Hematologic toxicity was found in 100% of the cats at some point during their treatment, but it was mostly grade I or II. Neutropenia, thrombocytopenia and anemia occurred in 16/21, 21/21 and 15/21 cats, respectively.

CONCLUSIONS AND RELEVANCE

The LOPH protocol was well tolerated by cats with lymphoma and persistent FeLV viremia, and resulted in a better MST than similar studies with other protocols. Novel studies and controlled trials are necessary in order to evaluate the efficacy of different protocols according to the lymphoma subtype, anatomic form and FeLV status.