Effects of inhaled low-concentration xenon gas on naltrexone-precipitated withdrawal symptoms in morphine-dependent mice

BACKGROUND

Opioid withdrawal symptoms (OWS) are highly aversive and prompt unprescribed opioid use, which increases morbidity, mortality, and, among individuals being treated for opioid use disorder (OUD), recurrence. OWS are driven by sympathetic nervous system (SNS) hyperactivity that occurs when blood opioid levels wane. We tested whether brief inhalation of xenon gas, which inhibits SNS activity and is used clinically for anesthesia and diagnostic imaging, attenuates naltrexone-precipitated withdrawal-like signs in morphine-dependent mice.

METHODS

Adult CD-1 mice were implanted with morphine sulfate-loaded (60 mg/ml) minipumps and maintained for 6 days to establish morphine dependence. On day 7, mice were given subcutaneous naltrexone (0.3 mg/kg) and placed in a sealed exposure chamber containing either 21% oxygen/balance nitrogen (controls) or 21% oxygen/added xenon peaking at 30%/balance nitrogen. After 10 minutes, mice were transferred to observation chambers and videorecorded for 45 minutes. Videos were scored in a blind manner for morphine withdrawal behaviors. Data were analyzed using 2-way ANOVAs testing for treatment and sex effects.

RESULTS AND CONCLUSIONS

Xenon-exposed mice exhibited fewer jumps (P = 0.010) and jumping suppression was detectible within the first 10-minute video segment, but no sex differences were detected. Brief inhalation of low concentration xenon rapidly and substantially attenuated naltrexone-precipitated jumping in morphine-dependent mice, suggesting that it can inhibit OWS. If xenon effects translate to humans with OUD, xenon inhalation may be effective for reducing OWS, unprescribed opioid use, and for easing OUD treatment initiation, which could help lower excess morbidity and mortality associated with OUD.

Perioperative complications of using freezing nitrogen ethanol composite to treat bone tumors: Clinical experience from a single center

BACKGROUND

The cryoablation efficacy of semisolid freezing nitrogen ethanol composite (FNEC) has been demonstrated. We aimed to investigate the feasibility of adjuvant FNEC-assisted cryoablation in different bone cavity types by assessing the perioperative complication rates.

METHODS

The medical charts of patients who received intraoperative adjuvant cryoablation using semisolid FNEC for bone tumors from December 2013 to January 2018 were reviewed. The bone cavities were categorized into three types according to liquid spill potential (type 1, able to hold liquid without limb manipulation; type 2, required extensive limb manipulation to retain liquid; type 3, unable to retain liquid). The overall complication rate and the complication rates stratified by bone cavity type were determined.

RESULTS

Among the 76 patients, 30.3%, 57.9%, and 11.8% had type 1, 2, and 3 bone cavities, respectively. The mean follow-up time for perioperative complications was 43.5 ± 24.1 days. Five patients experienced complications, including two cases of skin damage, two cases of skin infection, and one case of fracture, yielding an overall perioperative complication rate of 6.4%. All cases of skin damage and skin infection were superficial and manageable by oral antibiotics. The patient with a pathologic fracture recovered well after being treated with open reduction and plate fixation. No neuropraxia was noted within the first few days postsurgery in any patient. The complication rates in type 1, 2, and 3 bone cavities were 13%, 4.6%, and 0%, respectively.

CONCLUSION

All bone cavity types had a low incidence of perioperative complications after treatment with adjuvant FNEC-assisted cryoablation. Semisolid FNEC-assisted cryoablation is a feasible alternative to overcome the liquid spill potential in bone cavities resulting from tumor resection and intralesional curettage.

Ammonia scavenger and glutamine synthetase inhibitors cocktail in targeting mTOR/β-catenin and MMP-14 for nitrogen homeostasis and liver cancer

The glutamine synthetase (GS) facilitates cancer cell growth by catalyzing de novo glutamine synthesis. This enzyme removes ammonia waste from the liver following the urea cycle. Since cancer development is associated with dysregulated urea cycles, there has been no investigation of GS's role in ammonia clearance. Here, we demonstrate that, although GS expression is increased in the setting of β-catenin oncogenic activation, it is insufficient to clear the ammonia waste burden due to the dysregulated urea cycle and may thus be unable to prevent cancer formation. In vivo study, a total of 165 male Swiss albino mice allocated in 11 groups were used, and liver cancer was induced by p-DAB. The activity of GS was evaluated along with the relative expression of mTOR, β-catenin, MMP-14, and GS genes in liver samples and HepG2 cells using qRT-PCR. Moreover, the cytotoxicity of the NH3 scavenger phenyl acetate (PA) and/or GS-inhibitor L-methionine sulfoximine (MSO) and the migratory potential of cells was assessed by MTT and wound healing assays, respectively. The Swiss target prediction algorithm was used to screen the mentioned compounds for probable targets. The treatment of the HepG2 cell line with PA plus MSO demonstrated strong cytotoxicity. The post-scratch remaining wound area (%) in the untreated HepG2 cells was 2.0%. In contrast, the remaining wound area (%) in the cells treated with PA, MSO, and PA + MSO for 48 h was 61.1, 55.8, and 78.5%, respectively. The combination of the two drugs had the greatest effect, resulting in the greatest decrease in the GS activity, β-catenin, and mTOR expression. MSO and PA are both capable of suppressing mTOR, a key player in the development of HCC, and MMP-14, a key player in the development of HCC. PA inhibited the MMP-14 enzyme more effectively than MSO, implying that PA might be a better way to target HCC as it inhibited MMP-14 more effectively than MSO. A large number of abnormal hepatocytes (5%) were found to be present in the HCC mice compared to mice in the control group as determined by the histopathological lesions scores. In contrast, PA, MSO, and PA + MSO showed a significant reduction in the hepatic lesions score either when protecting the liver or when treating the liver. The molecular docking study indicated that PA and MSO form a three-dimensional structure with NF-κB and COX-II, blocking their ability to promote cancer and cause gene mutations. PA and MSO could be used to manipulate GS activities to modulate ammonia levels, thus providing a potential treatment for ammonia homeostasis.

Skin thermal recovery following cryotherapy: a comparison of liquid nitrogen and liquid nitrous oxide

Cryotherapy is a common technique used in the management of superficial skin lesions, with current advice on the correct timing for freeze-thaw cycles based on nonscientific visual skin appearances. We investigated the effect of cryotherapy on thermal thawing times by creating a porcine skin model in a laboratory setting maintained at normal skin temperature and comparing liquid nitrogen and liquid nitrous oxide. Thermal assessment was performed using a thermal camera attached to an iPhone 11Pro® smartphone. Liquid nitrogen reduced skin temperature to -60 °C after 5 s of application, recovering to 0 °C after 70 s. Liquid nitrous oxide reduced skin temperature to -34.8 °C after 5 s but had a faster recovery to 0 °C after only 20 s. Both cryogens required a thawing period of 5 min to recover to normal skin temperature. We therefore suggest that optimum cellular degradation should allow for 5-min freeze-thaw cryotherapy cycles; a slower thawing period than is in current common practice.

Exhaled breath condensate profiles of U.S. Navy divers following prolonged hyperbaric oxygen (HBO) and nitrogen-oxygen (Nitrox) chamber exposures

Prolonged exposure to hyperbaric hyperoxia can lead to pulmonary oxygen toxicity (PO2tox). PO2tox is a mission limiting factor for special operations forces divers using closed-circuit rebreathing apparatus and a potential side effect for patients undergoing hyperbaric oxygen (HBO) treatment. In this study, we aim to determine if there is a specific breath profile of compounds in exhaled breath condensate (EBC) that is indicative of the early stages of pulmonary hyperoxic stress/PO2tox. Using a double-blind, randomized 'sham' controlled, cross-over design 14 U.S. Navy trained diver volunteers breathed two different gas mixtures at an ambient pressure of 2 ATA (33 fsw, 10 msw) for 6.5 h. One test gas consisted of 100% O2(HBO) and the other was a gas mixture containing 30.6% O2with the balance N2(Nitrox). The high O2stress dive (HBO) and low O2stress dive (Nitrox) were separated by at least seven days and were conducted dry and at rest inside a hyperbaric chamber. EBC samples were taken immediately before and after each dive and subsequently underwent a targeted and untargeted metabolomics analysis using liquid chromatography coupled to mass spectrometry (LC-MS). Following the HBO dive, 10 out of 14 subjects reported symptoms of the early stages of PO2tox and one subject terminated the dive early due to severe symptoms of PO2tox. No symptoms of PO2tox were reported following the nitrox dive. A partial least-squares discriminant analysis of the normalized (relative to pre-dive) untargeted data gave good classification abilities between the HBO and nitrox EBC with an AUC of 0.99 (±2%) and sensitivity and specificity of 0.93 (±10%) and 0.94 (±10%), respectively. The resulting classifications identified specific biomarkers that included human metabolites and lipids and their derivatives from different metabolic pathways that may explain metabolomic changes resulting from prolonged HBO exposure.

Protective mechanism of traditional Chinese medicine guizhi fuling pills against carbon tetrachloride-induced kidney damage is through inhibiting oxidative stress, inflammation and regulating the intestinal flora

BACKGROUND

Chemical or drug-induced kidney damage has been recognized as a critical cause of kidney failure. The oxidative stress, inflammation, and imbalance of intestinal flora caused by carbon tetrachloride (CCl₄) play a fundamental role in chronic kidney damage. Guizhi Fuling pills (GZFL) is a traditional formula consisting of five traditional Chinese medicinal herbs, which can promote blood circulation and improve kidney function. The underlying mechanisms of GZFL improving kidney damage are not fully understood yet.

AIM

The current study aimed to explore the effects of GZFL on CCl₄-induced kidney damage and intestinal microbiota in mice.

METHODS

Male ICR mice were intraperitoneally administered with 20% CCl₄ (mixed in a ratio of 1:4 in soybean oil) twice a week, for 4 weeks to induce kidney damage. Creatinine (CRE), urea nitrogen, antioxidant enzymes, and inflammatory cytokines were measured and the histology of the kidney, jejunum, and colon examination to assess kidney and intestinal damage. The expressions of nuclear factor-erythroid 2-related factor 2 (Nrf2) family members, nucleotide-binding domain and leucine-rich repeat protein 3 (NLRP3) inflammasome in kidney tissues, and the tight junction proteins in colonic tissues were detected by Western blot. The gut microbiota was analyzed through 16S rRNA gene sequencing.

RESULTS

GZFL treatment decreased the serum CRE and urea nitrogen levels. Moreover, GZFL reduced the levels of pro-inflammatory cytokines and increased antioxidant enzyme activities in kidney and colonic tissues. GZFL improved the kidney, jejunum, and colon histology. Furthermore, GZFL inhibited the expressions of NLRP3, ASC, and cleaved-Caspase-1, while Nrf2, HO-1, NQO1, GCLM, and tight junction proteins were increased. The dysbiosis of intestinal microbiota improved after GZFL treatment.

CONCLUSIONS

This study showed that GZFL could improve kidney damage, which might be mainly via the integrated regulations of the Nrf2 pathway, NLRP3 inflammasome, and composition of intestinal microbiota.

Bone defect reconstruction with autologous bone inactivated with liquid nitrogen after resection of primary limb malignant tumors: An observational study

Surgical treatment of malignant bone tumors comprises tumor resection and reconstruction. The most commonly used reconstruction method is prosthesis replacement, which achieves good early function, but has a high long-term incidence of complications. Another reconstruction option is autologous bone replantation, which has the advantages of anatomical matching and no need for large bone bank support. Few studies have evaluated reconstruction with liquid nitrogen-inactivated autogenous bone.The present study aimed to evaluate the oncological results, bone healing results, complications, and indications of reconstruction with liquid nitrogen-inactivated autogenous bone grafts.The study population comprised 21 consecutive patients. The tumor site was the tibia in 9 cases, femur in 8, and humerus in 4. There were 37 osteotomy ends in total. After freezing and rewarming, the medullary cavity of the autogenous bone was filled with antibiotic bone cement. Seventeen patients received bilateral plate fixation, 2 received intramedullary nail and distal plate fixation, and 2 received single plate fixation.The average follow-up was 31 ± 6 months. Eighteen patients survived without tumors, and the 3-year survival rate was 80.4%. All cases had adequate surgical margins, but recurrence developed in 1 patient. Metastasis occurred in 3 patients, who all died of metastasis. Intraoperative inactivated bone fracture occurred in 1 patient, and screw breakage was found in 1 patient. Nonunion occurred at 1 humeral diaphysis osteotomy site, and 1 patient was lost to follow-up; the average healing time of the other 35 ends was 13 ± 6 months, and the bone healing rate was 97.2%. The average bone healing times in the metaphysis and diaphysis were 9 ± 3 months and 15 ± 6 months (P = .003). The average bone healing times in the upper and lower limbs were 16.6 ± 7.4 months and 12.3 ± 5.8 months (P = .020). The average Muscle and Skeletal Tumor Society score was 28 ± 3 (21-30) in the 18 survivors.Liquid nitrogen-inactivated autologous bone replantation for primary malignant limb tumor was safe and effective, as shown by the relatively low complication rate, high bone healing rate, and satisfactory postoperative function. This is a reliable biological reconstruction method for malignant bone tumors with specific site and bone destruction characteristics.

Regeneration of Osteonecrosis of Canine Scapho-lunate Using Bone Marrow Stromal Cells: Possible Therapeutic Approach for Kienböck Disease

We evaluated the ability of canine bone marrow stromal cells (cBMSCs) to regenerate bone in a cavity of the scapholunate created by curretage and freeze–thawing with liquid nitrogen (LN). Autologous BMSCs were harvested from the iliac crest and expanded in vitro. Their potential to differentiate into osteo-, chondro-, and adipogenic lineages was confirmed using a standard differentiation induction assay. LN-treated scapholunates showed no regeneration of bone tissue when the cavity was left alone, demonstrating severe collapse and deformity as observed in human Kienböck disease. A combination of β-tri-calcium phosphate and a vascularized bone graft with autologous fibroblasts failed to regenerate bone in the LN-treated cavity. When the same procedure was performed using BMSCs, however, LN-treated scapholunates showed no collapse and deformity, and the cavity was completely filled with normal cancerous bone within 4 weeks. These results suggested the potential of using BMSCs to treat Kienböck disease.

Objective vs. Subjective Evaluation of Cognitive Performance During 0.4-MPa Dives Breathing Air or Nitrox

BACKGROUND

Divers try to limit risks associated with their sport, for instance by breathing enriched air nitrox (EANx) instead of air. This double blinded, randomized trial was designed to see if the use of EANx could effectively improve cognitive performance while diving.

METHODS

Eight volunteers performed two no-decompression dry dives breathing air or EANx for 20 min at 0.4 MPa. Cognitive functions were assessed with a computerized test battery, including MathProc and Ptrail. Measurements were taken before the dive, upon arrival and after 15 min at depth, upon surfacing, and at 30 min postdive. After each dive subjects were asked to identify the gas they had just breathed.

RESULTS

Identification of the breathing gas was not possible on subjective assessment alone, while cognitive assessments showed significantly better performance while breathing EANx. Before the dives, breathing air, mean time to complete the task was 1795 ms for MathProc and 1905 ms for Ptrail. When arriving at depth MathProc took 1616 ms on air and 1523 ms on EANx, and Ptrail took 1318 ms on air and and 1356 ms on EANx, followed 15 min later by significant performance inhibition while breathing air during the ascent and the postdive phase, supporting the concept of late dive/postdive impairment.

DISCUSSION

The results suggest that EANx could protect against decreased neuro-cognitive performance induced by inert gas narcosis. It was not possible for blinded divers to identify which gas they were breathing and differences in postdive fatigue between air and EANx diving deserve further investigation.Germonpré P, Balestra C, Hemelryck W, Buzzacott P, Lafère P. Objective vs. subjective evaluation of cognitive performance during 0.4-MPa dives breathing air or nitrox. Aerosp Med Hum Perform. 2017; 88(5):469-475.

Optimising cryosurgery technique

BACKGROUND

Cryosurgery is an effective, simple and inexpensive treatment used extensively in general practice and dermatology. It is used most commonly for actinic keratoses and warts; however, a large number of benign, premalignant and malignant skin diseases can also be treated.

OBJECTIVE

The objective of this article is to help readers improve their cryosurgery technique.

DISCUSSION

Application of the cryogenic agent (most commonly liquid nitrogen) to the skin induces rapid freezing followed by slow thawing. This produces cell injury, vascular stasis and occlusion, and inflammation. The quantity of cryogen delivered onto the skin (dose), technique, duration of thawing and amount of surrounding tissue frozen are dependent on the body region and type of lesion. If clinical diagnosis is not possible, either a skin biopsy or referral to a dermatologist is recommended. We strongly discourage blind treatment of undiagnosed skin lesions.

Indications for prophylactic osteosynthesis associated with curettage in benign and low-grade malignant primitive bone tumors of the distal femur in adult patients: a case series

BACKGROUND

The aim of the study was to evaluate whether the use of preventive osteosynthesis after curettage in benign and primitive low-grade malignant bone tumor localized in the distal femur in adult patients provides sufficient mechanical stability to the system as to allow weight-bearing and reduce the risk of postoperative fracture. Additionally, lower limb function after curettage and preventive osteosynthesis was evaluated.

MATERIALS AND METHODS

We analyzed twelve cases of benign and low-grade malignant bone lesions of the distal femur in adult patients treated in our orthopedic department between 2008 and 2011 with curettage, bone filling and preventive osteosynthesis. All patients were treated with curettage with the use of high-speed cutters, plus liquid nitrogen as local adjuvant in low-grade malignant lesions, and filling of the lesion with bone graft or allograft or acrylic cement, followed by osteosynthesis.

RESULTS

No fractures or major complications were observed; good function of the knee was observed.

CONCLUSION

We recommend preventive osteosynthesis after curettage in patients with very large lesions (>5 cm, >60 cm³) or high functional requirements, in obese patients, and when local adjuvants are used.

LEVEL OF EVIDENCE

Level IV retrospective case-series study.

The cryoablation of lung tissue using liquid nitrogen in gel and in the ex vivo pig lung

PURPOSES

To examine the efficiency of cryoablation using liquid nitrogen in lung tissue, we measured the size and temperature distribution of the frozen area (iceball) in gel and in the ex vivo pig lungs.

METHODS

Cryoprobes with diameters of 2.4 and 3.4 mm (2.4D and 3.4D, respectively) were used. Three temperature sensors were positioned at the surface of the cryoprobe and at distances of 0.5 and 1.5 cm from the cryoprobe. The ex vivo pig lungs were perfused with 37 °C saline and inflated using ventilator to simulate in vivo lung conditions.

RESULTS

In gel, the 2.4D and 3.4D probes made iceballs of 3.9 ± 0.1 and 4.8 ± 0.3 cm in diameter, respectively, and the temperature at 1.5 cm from those probes reached -32 ± 8 and -53 ± 5 °C, respectively. In the pig lung, the 2.4D and 3.4D probes made iceballs of 5.2 ± 0.1 and 5.5 ± 0.4 cm in diameter, respectively, and the temperature at 1.5 cm from these probes reached -49 ± 5 and -58 ± 3 °C, respectively.

CONCLUSION

Liquid nitrogen cryoablation using both 2.4D and 3.4D probes made iceballs that were of sufficient size, and effective temperatures were reached in both gel and the ex vivo pig lung.

Enriched Air Nitrox Breathing Reduces Venous Gas Bubbles after Simulated SCUBA Diving: A Double-Blind Cross-Over Randomized Trial

Objective

To test the hypothesis whether enriched air nitrox (EAN) breathing during simulated diving reduces decompression stress when compared to compressed air breathing as assessed by intravascular bubble formation after decompression.

Methods

Human volunteers underwent a first simulated dive breathing compressed air to include subjects prone to post-decompression venous gas bubbling. Twelve subjects prone to bubbling underwent a double-blind, randomized, cross-over trial including one simulated dive breathing compressed air, and one dive breathing EAN (36% O₂) in a hyperbaric chamber, with identical diving profiles (28 msw for 55 minutes). Intravascular bubble formation was assessed after decompression using pulmonary artery pulsed Doppler.

Results

Twelve subjects showing high bubble production were included for the cross-over trial, and all completed the experimental protocol. In the randomized protocol, EAN significantly reduced the bubble score at all time points (cumulative bubble scores: 1 [0–3.5] vs. 8 [4.5–10]; P < 0.001). Three decompression incidents, all presenting as cutaneous itching, occurred in the air versus zero in the EAN group (P = 0.217). Weak correlations were observed between bubble scores and age or body mass index, respectively.

Conclusion

EAN breathing markedly reduces venous gas bubble emboli after decompression in volunteers selected for susceptibility for intravascular bubble formation. When using similar diving profiles and avoiding oxygen toxicity limits, EAN increases safety of diving as compared to compressed air breathing.

Trial Registration

ISRCTN 31681480

Nitrogen-bisphosphonate therapy is linked to compromised coenzyme Q10 and vitamin E status in postmenopausal women

BACKGROUND

Nitrogen-bisphosphonates (N-BPs) are the most widely used drugs for bone fragility disorders. Long-term or high-dose N-BP use is associated with unusual serious side effects such as osteonecrosis of the jaw, musculoskeletal pain, and atypical fractures of long bones. It has escaped notice that the pathway N-BPs block is central for the endogenous synthesis of coenzyme Q10, an integral enzyme of the mitochondrial respiratory chain and an important lipid-soluble antioxidant. Our objective was to assess the coenzyme Q10 and antioxidant status in relation to N-BP exposure in women with postmenopausal osteoporosis.

METHODS

Seventy-one postmenopausal women (age, 73.5 ± 5.5 y) with osteoporosis and no other malignancy were included in this cross-sectional study. Seventeen were treatment naive, 27 were on oral N-BP, and 27 were on i.v. N-BP.

RESULTS

Vitamin E γ-tocopherol levels (μmol/mL) were significantly reduced in N-BP users [oral, H(2) = 18.5, P = .02; i.v., H(2) = 25.2, P < .001; mean rank comparisons after Kruskal-Wallis test). Length of time (days) of N-BP exposure, but not age, was inversely associated with the coenzyme Q10/cholesterol ratio (μmol/mol) (β = -0.27; P = .025), which was particularly low for those on i.v. N-BP (mean difference = -35.0 ± 16.9; 95% confidence interval, -65.2 to -4.9; P = .02).

CONCLUSION

The degree of N-BP exposure appears related to compromised coenzyme Q10 status and vitamin E γ-tocopherol levels in postmenopausal women with osteoporosis. This phenomenon may link to certain adverse N-BP-associated effects. Confirmation of this would suggest that therapeutic supplementation could prevent or reverse certain complications of long-term N-BP therapy for at-risk individuals.

Aspects épidemiocliniques et évolutifs chez 157 cas de leishmaniose cutanée au Maroc

Connue au Maroc depuis la fin du XIX siècle, la leishmaniose cutanée (LC) constitue un problème de santé publique dans notre pays. Le but de notre travail est de décrire le profil épidémioclinique et l’évolution post thérapeutique chez les patients ayant une leishmaniose cutanée dans notre contexte. Nous avons effectué une étude rétrospective, basée sur l'exploitation des dossiers de malades ayant présenté une leishmaniose cutanée confirmée entre janvier 2003 et décembre 2012. Nous avons colligés 157 cas de leishmaniose cutanée. L’âge moyen des patients était de 34.5 ans avec des extrêmes de 6 ans à 63 ans. Le sex-ratio était de 2.34 H/F. La durée d’évolution moyenne des lésions était de 3,6 mois avec des extrêmes de 2 semaines à 10 mois. Les lésions étaient uniques dans 29.5% des cas. Les lésions siégeaient sur membres dans 63%. La forme ulcèro- croûteuse touchait plus de 48%. Le Glucantime était utilisé dans 29.3% des cas, l'azote liquide était utilisé chez 111 autres. L’évolution post-thérapeutique était favorable avec disparition quasi-complète des lésions dans un délai variant de 6 à 10 semaines, au prix de cicatrices inesthétiques chez 14 patients. La leishmaniose cutanée continue à poser un vrai problème de santé publique dans notre pays. L’émergence de formes sévères et résistantes à travers le monde doit inciter à multiplier et renforcer les mesures prophylactiques.

Liquid nitrogen spray cryotherapy in Barrett's esophagus with high-grade dysplasia: long-term results

BACKGROUND

Liquid nitrogen endoscopic spray cryotherapy can safely and effectively eradicate high-grade dysplasia in Barrett's esophagus (BE-HGD). Long-term data on treatment success and safety are lacking.

OBJECTIVE

To assess the long-term safety and efficacy of spray cryotherapy in patients with BE-HGD.

DESIGN

Single-center, retrospective study.

SETTING

Tertiary-care referral center.

PATIENTS

A total of 32 patients with BE-HGD of any length.

INTERVENTION

Patients were treated with liquid nitrogen spray cryotherapy every 8 weeks until complete eradication of HGD (CE-HGD) and intestinal metaplasia (CE-IM) was found by endoscopic biopsy. Surveillance endoscopy with biopsies was performed for at least 2 years.

MAIN OUTCOME MEASUREMENTS

CE-HGD, CE-IM, durability of response, disease progression, and adverse events.

RESULTS

CE-HGD was 100% (32/32), and CE-IM was 84% (27/32) at 2-year follow-up. At last follow-up (range 24-57 months), CE-HGD was 31/32 (97%), and CE-IM was 26/32 (81%). Recurrent HGD was found in 6 (18%), with CE-HGD in 5 after repeat treatment. One patient progressed to adenocarcinoma, downgraded to HGD after repeat cryotherapy. BE segment length ≥3 cm was associated with a higher recurrence of IM (P = .004; odds ratio 22.6) but not HGD. No serious adverse events occurred. Stricture was seen in 3 patients (9%), all successfully dilated.

LIMITATIONS

Retrospective study design, small sample size.

CONCLUSION

In patients with BE-HGD, liquid nitrogen spray cryotherapy has an acceptable safety profile and success rate for eliminating HGD and IM and is associated with a low rate of recurrence or progression to cancer with long-term follow-up.

[A woman with an itchy skin rash on her buttock]

A 24-year-old pregnant woman presented with a severely itchy skin rash on her left buttock after a journey to Thailand. The erythematous lesion appeared as 'cutaneous larva migrans', a skin disease in humans, caused by the larvae of various nematode parasites of the hookworm family (Ancylostomatidae). Due to her pregnancy, the patient was treated with local application of liquid nitrogen instead of oral anthelmintic therapy.

Cryosurgical treatment of warts: dimethyl ether and propane versus liquid nitrogen - case report and review of the literature

For years, dermatologists have relied on cryotherapy with liquid nitrogen as a safe and effective treatment for warts. More recently, several over-the-counter (OTC) wart-freezing therapies have become available. Manufacturers have substituted liquid nitrogen with dimethyl ether and propane (DMEP), and marketed these new preparations to be safe and effective alternatives to in-office cryotherapy with liquid nitrogen. However, data from in vitro studies and comparative studies in humans refute manufacturers' claims that these products reproduce in-office cryotherapy.

Fluence correction factors and stopping power ratios for clinical ion beams

BACKGROUND

In radiation therapy, the principal dosimetric quantity of interest is the absorbed dose to water. Therefore, a dose conversion to dose to water is required for dose deposited by ion beams in other media. This is in particular necessary for dose measurements in plastic phantoms for increased positioning accuracy, graphite calorimetry being developed as a primary standard for dose to water dosimetry, but also for the comparison of dose distributions from Monte Carlo simulations with those of pencil beam algorithms.

MATERIAL AND METHODS

In the conversion of absorbed dose to phantom material to absorbed dose to water the water-to-material stopping power ratios (STPR) and the fluence correction factors (FCF) for the full charged particle spectra are needed. We determined STPR as well as FCF for water to graphite, bone (compact), and PMMA as a function of water equivalent depth, z(w), with the Monte Carlo code SHIELD-HIT10A. Simulations considering all secondary ions were performed for primary protons as well as carbon, nitrogen and oxygen ions with a total range of 3 cm, 14.5 cm and 27 cm as well as for two spread-out Bragg-peaks (SOBP). STPR as a function of depth are also compared to a recently proposed analytical formula.

RESULTS

The STPR are of the order of 1.022, 1.070, and 1.112 for PMMA, bone, and graphite, respectively. STPR vary only little with depth except close to the total range of the ion and they can be accurately approximated with an analytical formula. The amplitude of the FCF depends on the non-elastic nuclear interactions and it is unity if these interactions are turned off in the simulation. Fluence corrections are of the order of a percent becoming more pronounced for larger depths resulting in dose difference of the order of 5% around 25 cm. The same order of magnitude is observed for SOBP.

CONCLUSIONS

We conclude that for ions with small total range (z(w-eq) ≤3 cm) dosimetry without applying FCF could in principle be performed in phantoms of materials other than water without a significant loss of accuracy. However, in clinical high-energy ion beams with penetration depths z(w-eq) ≥3 cm, where accurate positioning in water is not an issue, absorbed dose measurements should be directly performed in water or accurate values of FCF need to be established.

Advanced cancer of the extremities treated by cryosurgery

AIM

Cryosurgery with liquid nitrogen (LN) is a safe and effective method to treat skin cancer. With the correct protocol, its efficacy is extended to advanced and inoperable tumors. The aim of this study was to report the author's experience in the treatment of advanced squamous-cell carcinomas of the extremities.

METHODS

Forty-eight patients (31 women and 17 men; mean age of 79 years) with 50 advanced squamous-cell carcinomas (SCC) of the extremities were treated with open and thick LN spray--two freeze-thaw cycles--reaching a temperature around -50 ºC inside the tumor, but not less than -20 ºC in the tumor limits and the underlying structures. Temperature monitoring was made by thermocouples. All cases in this series were treated by the author.

RESULTS

The overall cure rate was 88%, with follow-up between 1 and 8 years (mean of 2.64 years).

CONCLUSION

This cryosurgical method is an effective treatment for advanced cancers of the extremities, yielding a high cure rate and, in many cases, preventing amputation.

[Theoretical analysis of recompression-based therapies of decompression illness]

Theoretical analysis is concerned with the benefits of oxygen, air and nitrogen-helium-oxygen recompression schedules used to treat decompression illness in divers. Mathematical modeling of tissue bubbles dynamics during diving shows that one-hour oxygen recompression to 200 kPa does not diminish essentially the size of bubble enclosed in a layer that reduces tenfold the intensity of gas diffusion from bubbles. However, these bubbles dissolve fully in all the body tissues equally after 2-hr. air compression to 800 kPa and ensuing 2-d decompression by the Russian navy tables, and 1.5-hr. N-He-O2 compression to this pressure followed by 5-day decompression. The overriding advantage of the gas mixture recompression is that it obviates the narcotic action of nitrogen at the peak of chamber pressure and does not create dangerous tissue supersaturation and conditions for emergence of large bubbles at the end of decompression.

Positron emission tomography in ARDS: a new look at an old syndrome

This is a review of some of the main findings obtained by positron emission tomography (PET) concerning the pathophysiology of acute respiratory distress syndrome (ARDS) and acute lung injury. PET (which is nowadays often combined with computed tomography) is a functional imaging technique based on the detection of a labeled molecule administered to a subject. Based on the molecule used, different lung functions can be imaged. Examples include inhaled, labeled nitrogen, which allows us to visualize regional aeration and ventilation, whereas lung perfusion has been studied by means of labeled water or by injected nitrogen dissolved in saline. With this latter technique, a global assessment of regional gas exchange is possible. Administration of [18F]FDG facilitates the imaging of cellular metabolic activity, reflecting an acute neutrophil-sustained inflammatory process. This technique has been used in experimental ARDS and, more recently, in patients. It showed, for example, that inflammatory activity of the lungs is markedly increased even in "normally aerated" regions at levels that are, in some cases, even higher than in the non-aerated regions.

[Dynamics of characteristics of the immune, cardiovascular, and autonomic nervous systems during aerocryotherapy in patients with different "immune health" status]

This study has demonstrated that subjects of different "immune health" status also differ in the activity of the vegetative nervous system. Aerocryotherapy was shown to have stimulatory effect on the immune system and decreased the hyperactivity of the parasympathetic nervous system especially in people suffering immune insufficiency.

Revising concepts of artificial nutrition in contemporary surgery: from energy and nitrogen to immuno-metabolic support

Profound changes in perioperative management, namely "fast track surgery" have been recently proposed. This is a bundle of various techniques used for subjects undergoing elective operations that allows an improved well-being, faster recovery, shorter hospitalization and better outcome. From a nutritional point of view this new approach translates into a more rapid return of bowel function and thus to safely tolerate oral re-feeding within 1-3 days even after major operations. Nevertheless, the classic indications for perioperative artificial nutritional support remain valid but they should now apply only to a minority of patients. Extensive research in the last 20 years has clearly shown that modifying the composition of standard nutritional feeds by adding supernormal doses of specific substrates that have immuno-modulatory, anti-inflammatory, anabolic, and tissue protective ability often translates into improved surgical outcome. The most convincing and reproducible results were obtained on the reduction of infectious complication by the perioperative use of enteral formulas enriched with arginine and omega-3 fatty acids.

Nitrogen sparing therapy revisited 2009

Although the protocol that most experienced metabolic centers in the United States follow for treating acute hyperammonemia in urea cycle disorders (UCDs) is similar to that proposed by Brusilow and Batshaw in the early 1980s, over the years a steady evolution has taken place. Continued developments in intensive care, surgical and hemodialysis techniques, fluid and electrolyte management, cardiovascular support, and emergency transport have contributed to improved management of acute hyperammonemia. Compared to historical data, survival of urea cycle patients has also improved following treatment with alternative pathway therapy, in addition to appropriate supportive care, including the provision of adequate calories to prevent catabolism and promote anabolism and hemodialysis if needed. However, overall neurological outcomes have been suboptimal. There are currently a number of exciting prospective new therapies on the horizon, including novel medications or cell-based treatments. Nevertheless, the therapeutic expertise that is currently in place at centers specializing in management of metabolic emergencies already has the potential to improve survival and outcome in these children significantly. The early identification of UCD patients so that transport to a metabolic treatment center may be carried out without delay continues to be a major area of focus and challenge.

Guiding principles in choosing a therapeutic table for DCI hyperbaric therapy

Hyperbaric therapy is the basis of treatment for pervasive development disorders. For this reason, the choice of the right therapeutic table for each case is critical. Above all, the delay in recompression time with respect to the first symptoms and to the severity of the case must be considered. In our experience, the use of low-pressure oxygen tables resolves almost all cases if recompression takes place within a short time. When recompression is possible almost immediately, the mechanical effect of reduction on bubble volume due to pressure is of remarkable importance. In these cases, high-pressure tables can be considered. These tables can also be used in severe spinal-cord decompression sickness. The preferred breathing mixture is still disputed. Heliox seems to be favored because it causes fewer problems during the recompression of divers, and above all, because nitrox can cause narcosis and contributes nitrogen. Saturation treatment should be avoided or at least used only in special cases. In cases of arterial gas embolism cerebral injury, it is recommended to start with an initial 6 ATA recompression only if the time between symptom onset and the beginning of recompression is less than a few hours.

An in vitro study comparing temperatures of over-the-counter wart preparations with liquid nitrogen

BACKGROUND

Over-the-counter (OTC) wart-freezing therapies have appeared on the market claiming that they reproduce in-office cryotherapy.

OBJECTIVE

We sought to determine whether these OTC home wart removal products are as cold as liquid nitrogen.

METHODS

The coldness obtained by 3 representative commercial wart products, and liquid nitrogen, was assessed using a thermometer calibrated from -100 degrees C to 50 degrees C. Temperatures of the commercial wart products used were measured and compared with those obtained with liquid nitrogen.

RESULTS

None of the OTC coolants were as cold as liquid nitrogen, and they did not lower temperature as quickly as liquid nitrogen.

LIMITATIONS

This study did not evaluate the clinical efficacy of any of the agents studied.

CONCLUSIONS

Despite advertising messages, OTC refrigerants do not achieve freezing equivalent to liquid nitrogen.

Plasma skin regeneration technology

Plasma skin regeneration is a novel type of skin rejuvenation technology developed over the last 3 years. Plasma is the fourth state of matter in which electrons are stripped from atoms to form an ionized gas. Although high temperature plasmas have been used in surgery for over a decade, plasma had previously been used as a conduction medium for electric current. Unlike lasers which rely on the principle of selective photothermolysis to deliver heat to specific targets in the skin, plasma technology delivers heat energy directly to tissue upon contact without reliance on skin chromophores. The plasma itself produces controlled thermal damage to the skin surface to elicit changes such as new collagen formation and improvement in photodamaged skin. The technology can be used at varying energies for different depths of effect, from superficial epidermal effects to deeper dermal heating.

Cryospray ablation (CSA) in the palliative treatment of squamous cell carcinoma of the esophagus

Background

Esophageal carcinoma is the ninth most prevalent cancer worldwide with squamous cell carcinoma (SCCA) and adenocarcinoma accounting for the vast majority of new cases (13,900 in 2003). Cure rates in the U.S. are less than 10%, similar to lung cancer. More than 50% of patients with esophageal carcinoma present with unresectable or metastatic disease, are not surgical candidates, or display disease progression despite the addition of neoadjuvant chemoradiotherapy to surgery. Need for improved palliation exits.

Case presentation

This case describes a 73-year-old African American male who presented with recurrent squamous cell carcinoma (SCCA) of the esophagus who has a achieved complete remission for 24 months via endoscopic cryospray ablation.

Conclusion

Endoscopic cryo spray ablation warrants further investigation as a palliative treatment modality for esophageal cancer. This is the first reported case in the medical literature.

Balloon angioplasty for ductus arteriosus in infant with ductal origin of the left pulmonary artery: combination with nitrogen inhalation therapy

An infant with truncus arteriosus (Van Praagh A3; isolated left pulmonary artery (LPA) and ductal origin of the LPA) had an extremely stenotic ductus arteriosus (DA) and the LPA could not be demonstrated. As a salvage operation, balloon angioplasty was performed for the stenotic DA at 8 days of age. The minimum lumen diameter of the DA increased from 0.7 to 2.7 mm. After the procedure, the LPA tree was well demonstrated and total pulmonary blood flow increased. Nitrogen inhalation was begun with a nasal positive airway pressure system in order to regulate pulmonary blood flow. Repeat balloon angioplasty was performed at 33 days of age for the restenosed DA. The infant's general condition was stabilized until undergoing pulmonary artery reconstruction and modified Blalock-Taussig shunt at 4 months of age, and definitive repair at 11 months of age. The combination of balloon angioplasty and nitrogen inhalation therapy enabled simultaneous growth of the LPA tree and regulation of total pulmonary blood flow, which could be a useful strategy for complex congenital heart diseases with unbalanced pulmonary blood flow.

Plasma skin regeneration technology

Plasma skin regeneration (PSR) technology uses energy delivered from plasma rather than light or radiofrequency. Plasma is the fourth state of matter in which electrons are stripped from atoms to form an ionized gas. The plasma is emitted in a millisecond pulse to deliver energy to target tissue upon contact without reliance on skin chromophores. The technology can be used at varying energies for different depths of effect, from superficial epidermal sloughing to deeper dermal heating. With the Portrait PSR device (Rhytec, Inc.) there are three treatment guidelines termed PSR1, PSR2, and PSR3. The PSR1 protocol uses a series of low-energy treatments (1.0,1.2 Joules) spaced 3 weeks apart. The PSR2 protocol uses one high-energy pass (3.0, 4.0 Joules) performed in a single treatment, and the PSR3 protocol uses two high-energy passes (3.0 4.0 Joules) performed in a single treatment. All protocols improve fine lines, textural irregularities, and dyspigmentation; however, skin tightening is probably more pronounced with the high-energy treatments.

Liquid Nitrogen Cryotherapy of Advancing Wavelike Epitheliopathy

PURPOSE

To describe a method for treating advancing wavelike epitheliopathy (AWE) with liquid nitrogen cryotherapy spray.

METHODS

A Brymill liquid nitrogen cryotherapy canister with a "D" tip was used to freeze AWE in 5 cases in 4 patients. Freezing time was approximately 1-2 seconds and was performed twice. The affected limbus and corneal epithelium were treated in this manner.

RESULTS

In each case, AWE resolved within 2 weeks, with no recurrence at 1 year.

CONCLUSION

Liquid nitrogen cryotherapy is a safe and effective treatment of advancing wavelike epithelopathy.

A prospective randomized controlled trial to determine if cryotherapy can reduce the pain of patients with minor form of recurrent aphthous stomatitis

BACKGROUND

Tissue cooling has long been used in the management of both acute and chronic pain.

OBJECTIVE

To determine whether the application of cryotherapy can reduce the pain of patients with minor form of recurrent aphthous stomatitis.

STUDY DESIGN

Twenty adult patients who had 2 discrete aphthous stomatitides in the labial mucosa at the same time were included in this prospective, randomized, and placebo-controlled study. One of the 2 aphthous stomatitides was treated with cryotherapy, the other serving as a control. The pain of aphthous stomatitis was scored by the patient on a 6-point scale (from 0 to 5). The size of the aphthous stomatitis was also measured.

RESULTS

At any interval, no statistical difference was found between the cryotherapy-treated aphthous stomatitis and the control in the change in the value of pain severity, nor was any statistical difference found in the change in the size of the aphthous stomatitis. However, a trend toward less pain in the aphthous stomatitis receiving cryotherapy was noted.

CONCLUSION

These results suggest that application of cryotherapy on minor form of recurrent oral aphthous stomatitis has no beneficial analgesic effect compared to placebo.

Multifocal epithelial hyperplasia. Report of nine cases

Multifocal epithelial hyperplasia (MEH) is also known as focal epithelial hyperplasia, Heck's disease or multifocal papillomavirus-induced epithelial hyperplasia. It is characterised by the presence of multiple lesions in the oral mucosa of children and it has been associated with the presence of the human papillomavirus. The aim of this study was to determine the clinico-pathological features of the cases diagnosed as MEH in the Service of Dermatology of the Hospital Manuel Gea González (SDHMGG). The files of the SDHMGG were reviewed and all cases diagnosed as MEH were retrieved. Nine MEH cases were found. Most of the patients were 20 year-old or younger (67%) and females were more commonly affected (78%). All patients presented multiple lesions and always, close relatives with similar lesions were found. Lesions were located most commonly in the buccal mucosa, lower lip and commissures. MEH is a soft tissue intraoral condition that needs treatment solely of the traumatised lesions or those with cosmetic problems. Remaining lesions will disappear with the age of the patients. It is suggested that this entity should be named multifocal epithelial hyperplasia since this name describes better the clinico-pathological and microscopic features of the disease.

Supplemental nitrogen inhalation therapy in very low-birth-weight infants with patent ductus arteriosus

Very low-birth weight infants with patent ductus arteriosus (PDA) accompanied by severe heart failure do not respond to indomethacine therapy. It is essential to stabilize the general condition of these infants until surgical intervention. We tried to regulate the pulmonary blood flow to control congestive heart failure by administering supplemental nitrogen inhalation therapy to six very low-birth-weight infants with PDA. After the inhalation of supplemental nitrogen gas was begun, the arterial oxygen saturation and partial oxygen pressure immediately decreased. Furthermore, the blood pH, systolic pressure, and urine output significantly increased. The infants were well stabilized. Furthermore, there were no complications related to nitrogen gas inhalation. Supplemental nitrogen inhalation therapy is an effective and feasible therapy for severe congestive heart failure in very low-birth-weight infants with PDA.

Reconstruction using an autograft containing tumour treated by liquid nitrogen

We describe a method of reconstruction using tumour-bearing autograft treated by liquid nitrogen in 28 patients. The operative technique consisted of en bloc excision of the tumour, removal of soft tissue, curettage of the tumour, drilling and preparation for internal fixation or prosthetic replacement before incubation for 20 minutes in liquid nitrogen, thawing at room temperature for 15 minutes, thawing in distilled water for ten minutes, and internal fixation with an intramedullary nail, plate or composite use of prosthetic replacement. Bone graft or cement was used to augment bone strength when necessary. The limb function was rated as excellent in 20 patients (71.4%), good in three (10.7%), fair in three (10.7%), and poor in two (7.1%). At the final follow-up six patients had died at a mean of 19.8 months after the operation, while 21 remained free from disease with a mean follow-up of 28.1 months (10 to 54). One patient is alive with disease. Bony union was seen at a mean of 6.7 months after the operation in 26 patients. Complications were encountered in seven patients, including three deep infections, two fractures, and two local recurrences. All were managed successfully. Our results suggest that this is a simple and effective method of biological reconstruction.

The cyclooxygenase-2 inhibitor GW406381X [2-(4-ethoxyphenyl)-3-[4-(methylsulfonyl)phenyl]-pyrazolo[1,5-b]pyridazine] is effective in animal models of neuropathic pain and central sensitization

The pathogenic form of the cyclooxygenase (COX) enzyme, COX-2, is also constitutively present in the spinal cord and has been implicated in chronic pain states in rat and man. A number of COX-2 inhibitors, including celecoxib and rofecoxib, are already used in man for the treatment of inflammatory pain. Preclinically, the dual-acting COX-2 inhibitor, GW406381X [2-(4-ethoxyphenyl)-3-[4-(methylsulfonyl)phenyl]-pyrazolo[1,5-b]pyridazine, where X denotes the free base], is as effective as rofecoxib and celecoxib in the rat established Freund's Complete Adjuvant model with an ED(50) of 1.5 mg/kg p.o. compared with 1.0 mg/kg p.o. for rofecoxib and 6.6 mg/kg p.o. for celecoxib. However, in contrast to celecoxib (5 mg/kg p.o. b.i.d.) and rofecoxib (5 mg/kg p.o. b.i.d.), which were without significant effect, GW406381X (5 mg/kg p.o. b.i.d.) fully reversed mechanical allodynia in the chronic constriction injury model and reversed thermal hyperalgesia in the mouse partial ligation model, both models of neuropathic pain. GW406381X, was also effective in a rat model of capsaicin-induced central sensitization, when given intrathecally (ED(50) = 0.07 mug) and after chronic but not acute oral dosing. Celecoxib and rofecoxib had no effect in this model. Several hypotheses have been proposed to try to explain these differences in efficacy, including central nervous system penetration, enzyme kinetics, and potency. The novel finding of effectiveness of GW406381X in these models of neuropathic pain/central sensitization, in addition to activity in inflammatory pain models and together with its central efficacy, suggests dual activity of GW406381X compared with celecoxib and rofecoxib, which may translate into greater efficacy in a broader spectrum of pain states in the clinic.