Treatment Result of the Mucopexy-Recto Anal Lifting Method for Hemorrhoids in Comparison with Ligation and Excision, and Aluminum Potassium Sulfate and Tannic Acid Sclerotherapy

The outcomes of Mucopexy-Recto Anal Lifting (MuRAL) in hemorrhoid surgery were compared with ligation and excision (LE), and aluminum potassium sulfate and tannic acid sclerotherapy (ALTA). In this study, we conducted a 3-year follow-up study of MuRAL (380 cases) and compared it with LE (1417 cases) and ALTA (541 cases) performed at the same period. Operative time, mean hospital stay, postoperative pain, postoperative complications, and recurrence were compared and examined retrospectively. The mean operative time was the longest for MuRAL, followed by LE, and then ALTA at 29.1, 21.5, and 12.4 minutes, and the mean length of hospital stay was 6.2, 10.6, and 1.3, days, respectively. Based on the frequency of injectable analgesic use, postoperative pain was clearly milder in MuRAL and ALTA than in LE. The recurrence rates were 3.2% with MuRAL, 1.1% with LE, and 12.4% with ALTA. Early postoperative low-grade fever and bowel movement urgency were observed in all surgeries, but these were minor and did not pose a safety problem. LE is painful and requires prolonged hospitalization but is the most curative; ALTA is simple and can be performed as a day surgery but has a high recurrence rate. MuRAL was less painful than LE and had a lower recurrence rate than ALTA. In recent years, there have been various innovations in the surgical treatment of hemorrhoids, and choosing a technique that is appropriate for the condition of the hemorrhoid and patient's needs is necessary. MuRAL can be one of the options for hemorrhoid treatment as a “cure without cutting” method.

The Japan-Multimodal Intervention Trial for Prevention of Dementia (J-MINT): The Study Protocol for an 18-Month, Multicenter, Randomized, Controlled Trial

Background/Objectives

The Japan-multimodal intervention trial for prevention of dementia (J-MINT) is intended to verify the effectiveness of multi-domain interventions and to clarify the mechanism of cognitive improvement and deterioration by carrying out assessment of dementia-related biomarkers, omics analysis and brain imaging analysis among older adults at high risk of dementia. Moreover, the J-MINT trial collaborates with partnering private enterprises in the implementation of relevant interventional measures. This manuscript describes the study protocol.

Design/Setting

Eighteen-month, multi-centered, randomized controlled trial.

Participants

We plan to recruit 500 older adults aged 65–85 years with mild cognitive impairment. Subjects will be centrally randomized into intervention and control groups at a 1:1 allocation ratio using the dynamic allocation method with all subjects stratified by age, sex, and cognition.

Intervention

The multi-domain intervention program includes: (1) management of vascular risk factors; (2) group-based physical exercise and self-monitoring of physical activity; (3) nutritional counseling; and (4) cognitive training. Health-related information will be provided to the control group every two months.

Measurements

The primary and secondary outcomes will be assessed at baseline, 6-, 12-, and 18-month follow-up. The primary outcome is the change from baseline to 18 months in a global composite score combining several neuropsychological domains. Secondary outcomes include: cognitive change in each neuropsychological test, incident dementia, changes in blood and dementia-related biomarkers, changes in geriatric assessment including activities of daily living, frailty status and neuroimaging, and number of medications taken.

Conclusions

This trial that enlist the support of private enterprises will lead to the creation of new services for dementia prevention as well as to verify the effectiveness of multi-domain interventions for dementia prevention.

Electronic Supplementary Material

Supplementary material is available for this article at 10.14283/jpad.2021.29 and is accessible for authorized users.

Efficacy of neuromuscular electro stimulation on muscle strength in elderly patients with diabetes mellitus underwent cardiovascular surgery – a multicenter randomized controlled trial

Introduction

Cardiovascular surgery causes muscle weakness probably due to a postoperative increase in inflammatory cytokine production, and diabetes mellitus (DM) may promote the postoperative muscle weakness because of increased insulin resistance.

Purpose

A multicenter randomized controlled trial was conducted to examine the effects of postoperative neuromuscular electrical stimulation (NMES) on muscle strength for elderly patients with DM after cardiovascular surgery (UMIN000029940).

Methods

Patients underwent cardiovascular surgery were consecutive screened for eligibility (With DM and age ≥65 years) as study subjects. If eligible, patients were randomly assigned either to the NMES or the sham group. Both of group underwent NMES or sham stimulation (60 minutes / 5 times) and usual postoperative early mobilization program until postoperative day (POD) 7. The primary outcome was the percent change in knee extensor isometric muscle strength (%ΔKEIS) between preoperative to POD 7. Secondary outcomes were the percent change in usual (%ΔUsual walking speed) and maximum walking speed (%ΔMaximum walking speed) and grip strength (%ΔGS). Assessors for physical function were blinded to the outcomes. The statistician who was blinded to the allocation analyzed the data using preoperative value adjusted ANCOVA.

Results

Of 1151 consecutive patients screened for eligibility from February 2018 to January 2020, 158 participants (NMES group, n=79; sham group, n=79) were enrolled. NMES group demonstrated significantly lower %ΔKEIS compared with those in the sham group (Table). Among secondary outcomes, NMES group showed significantly lower %ΔMaximum walking speed and tendency of lower %ΔUsual walking speed and %ΔGS (Table).

Conclusion

NMES prevented postoperative muscle weakness in the elderly patients with DM, indicating that NMES along with early mobilization could be implicated as specific intervention to those populations.

Funding Acknowledgement

Type of funding source: None

A dose-finding approach for genomic patterns in phase I trials

Precision medicine is an emerging approach for disease treatment and prevention that accounts for individual variability in genes, environment, and lifestyle. Cancer is a genomic disease; therefore, the dose-efficacy and dose-toxicity relationships for molecularly targeted agents in cancer most likely differ, based on the genomic mutation pattern. The individualized optimal dose - the maximal efficacious dose with a clinically acceptable safety profile - may vary depending on the genomic mutation patterns and should be determined prior to the use of these agents in precision medicine. In addition, genes that influence the individualized optimal doses should be identified in early-phase development. In this study, we propose a novel dose-finding approach to identify the individualized optimal dose for molecularly targeted agents in phase I cancer trials. Individualized optimal dose determination and gene selection were conducted simultaneously based on L ₁ and L ₂ penalized regression. Similar to most reported dose-finding approaches, this study considers non-monotonic patterns for dose-efficacy and dose-toxicity relationships, as well as correlations between efficacy and toxicity outcomes based on multinomial distribution. Our dose-finding algorithm is based on the predictive probability calculated with an estimated penalized regression model. We compare the operating characteristics between the proposed and existing methods by simulation studies under various scenarios.

Pathological Features of Complete Atrioventricular Block in Dogs with Lymphocytic Myocarditis

The cardiac conduction system was examined histologically in 12 canine cases of lymphocytic myocarditis with complete atrioventricular (AV) block. Histological analysis showed active myocarditis characterized by intense infiltration of mononuclear cells, primarily lymphoid, associated with degeneration and necrosis of the adjacent cardiomyocytes. Additionally, there was healing or healed myocarditis manifested by disappearance of cardiomyocytes and replacement fibrosis. This destructive inflammatory process of lymphocytic myocarditis involved the whole of the AV conduction system, resulting in loss and deletion of the conduction fibres, as well as the myocardium of all chambers. Such total or subtotal destruction of the AV conduction system caused by the inflammatory changes was thought to have set the stage for blocking AV conduction of cardiac impulses, but the aetiology of the lymphocytic myocarditis was not elucidated.

Post-occlusional hyperemia for fractional flow reserve assessment and pull-back curve analysis

Balloon occlusion is a potential method for inducing hyperemia to measure post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR). The objective of this study was to determine the clinical usefulness of post-occlusional hyperemia. FFRs measured using post-occlusional hyperemia caused by 30 (FFR_occl30) and 60 s (FFR_occl60) of balloon occlusion after PCI were compared in 60 lesions from 60 patients. The duration of hyperemia was also measured. There was a strong correlation between FFR_occl30 and FFR_occl60 (r = 0.969, p < 0.01). The duration of hyperemia was significantly longer with FFR_occl60 than with FFR_occl30 (68 ± 23 vs. 37 ± 15 s, p < 0.01). The time required for pullback curve analysis was around 45 s. However, in 7 (12%) cases, the duration of hyperemia with FFR_occl60 was < 45 s, which was not enough for pull-back curve analysis. To predict the duration of hyperemia with FFR_occl60 ≥ 45 s, the receiver operating characteristic curve analysis revealed a cut-off value of 25 s of hyperemia with FFR_occl30. FFR_occl30 is sufficient for diagnostic purposes. FFR_occl60 is suitable for pull-back curve analysis in select cases based on predictions made using the duration of hyperemia with FFR_occl30.

Development and analysis of patient-derived xenograft mouse models in intravascular large B-cell lymphoma

Intravascular large B-cell lymphoma (IVLBCL) is a distinct disease entity with the peculiar characteristic that tumor cells proliferate within vessels. Despite recent advances in understanding the disease from clinical aspects, the underlying pathogenesis remains unknown. Here we demonstrate analyses of IVLBCL biology using four xenograft mouse models established from primary IVLBCL samples. In all four models, the main characteristic of IVLBCL tumor cell proliferation within vessels was retained. Time-lapse engraftment analyses revealed that the tumor cells initially engrafted and proliferated in the sinusoids and vessels in the liver and then engrafted and proliferated in multiple organs. Intriguingly, serial passage of tumor cells from the adrenal gland of a transplanted mouse developed from primary patient bone marrow cells into a second mouse showed that the tumor cells mainly distributed into the adrenal gland in the second mouse, implying the existence of clonal selection and/or evolution at engraftment of a specific organ. Gene expression profiling analyses demonstrated that the gene set associated with cell migration was enriched for normal peripheral blood B cells, indicating that inhibition of cell migration might be involved in IVLBCL pathogenesis. In conclusion, the mouse xenograft models described here are essential tools for uncovering IVLBCL biology.

The features of clearance in recombinant factor IX (BeneFIX(®) )

INTRODUCTION

Dosage adjustment is very important to perform continuous infusion (CI) of recombinant factor IX (rFIX) concentrates more effectively and economically, and clearance (CL) is strongly related to the infusion rate. However, previous reports have shown that the CL of rFIX concentrates varies widely (4.2-11.4 mL kg(-1) h(-1) ).

AIM

The goal of this study was to gain a better understanding of the CL of the rFIX concentrate (BeneFIX(®) ) to precisely set the infusion rate of rFIX concentrates.

METHODS

We estimated CLs by five different calculation approaches: from area under the blood concentration-time curve (AUC), from in vivo recovery (IVR) and half-life, from actual FIX activity value during CI, and from the simulation by one-compartment model in seven patients with haemophilia B.

RESULTS

The mean CL calculated from AUC was 3.8 ± 0.4 mL kg(-1) h(-1) (range = 3.3-4.3 mL kg(-1) h(-1) ).

CONCLUSION

The mean CL calculated from IVR and distribution half-life was 4.4 ± 0.4 mL kg(-1) h(-1) (range = 4.0-5.1 mL kg(-1) h(-1) ). The mean CL calculated from IVR and terminal half-life was 2.1 ± 0.5 mL kg(-1) h(-1) (range = 1.7-2.8 mL kg(-1) h(-1) ). The mean CL during CI was 4.9 ± 0.6 mL kg(-1) h(-1) (range = 4.2-5.6 mL kg(-1) h(-1) ). In addition, when we simulated the theoretical CL using a one-compartment model, the adjusted mean CL during CI was 4.8 ± 0.5 mL kg(-1) h(-1) (range = 4.0-5.4 mL kg(-1) h(-1) ). The CL obtained from distribution half-life was comparable to the CL during CI, while the CL calculated from terminal half-life did not reflect actual CL. Further, the rFIX concentrate was characterized by a one-compartment model under certain conditions.

Can oncologists predict survival for patients with progressive disease after standard chemotherapies?

BACKGROUND

Prediction of prognosis is important for patients so that they can make the most of the rest of their lives. Oncologists could predict survival, but the accuracy of such predictions is unclear.

METHODS

In this observational prospective cohort study, 14 oncologists treating 9 major adult solid malignancies were asked to complete questionnaires predicting survival based on performance status, oral intake, and other clinical factors when patients experienced progressive disease after standard chemotherapies. Clinically predicted survival (cps) was calculated by the oncologists from the date of progressive disease to the predicted date of death. Actual survival (as) was compared with cps using Kaplan-Meier survival curves, and factors affecting inaccurate prediction were determined by logistic regression analysis. The prediction of survival time was considered accurate when the cps/as ratio was between 0.67 and 1.33.

RESULTS

The study cohort consisted of 75 patients. Median cps was 120 days (interquartile range: 60-180 days), and median as was 121 days (interquartile range: 40-234 days). The participating oncologists accurately predicted as within a 33% range 36% of the time; the survival time was overestimated 36% of time and underestimated 28% of the time. The factors affecting the accuracy of the survival estimate were the experience of the oncologist, patient age, and information given about the palliative care unit.

CONCLUSIONS

Prediction of cps was accurate for just slightly more than one third of all patients in this study. Additional investigation of putative prognostic factors with a larger sample size is warranted.

Pneumomediastinum and Subcutaneous Emphysema after High Pressure Air and Sand Injection Injury to the Upper Arm

We present a rare case of a 47-year-old man who developed pneumomediastinum and subcutaneous emphysema after a high pressure hose accidentally injected air and sand particles into his right upper arm. On presentation, he complained of dyspnoea and chest pain. He had palpable subcutaneous emphysema extending from the upper arm to his neck, face, and trunk. Plain X-ray films and computed tomography showed pneumomediastinum and subcutaneous emphysema, but no sand particles. Conservative treatment was done with close observation, and serial radiographs were obtained. There was complete resolution of the mediastinal and subcutaneous air after about two weeks with no evidence of infection. This was an extremely rare case of pneumomediastinum and severe subcutaneous emphysema occurring after accidental air injection injury to the upper arm. With regard to how air entered the mediastinal cavity, possible pathways are discussed. (Hong Kong j.emerg.med. 2014;21:51-54)

Usefulness and Problems of Intraosseous Infusion with the Bone Injection Gun™ Using Simulators Under Confined Space Conditions

Introduction

It is important to have a venous line for infusion as an emergency treatment for patients suffering from crush syndrome or bleeding under confined space (CS) conditions in disaster medicine. However, it is not easy to for Emergency Life-Saving Technicians (ELSTs) to establish a venous line in such settings. Although previous studies have described the use of mechanical intraosseous (IO) devices and IO access while wearing chemical protection gears, problems for the use of IO devices under CS conditions have not been considered. This study aimed to investigate usefulness and problems of using a Bone Injection Gun™ (BIG) for IO infusion by ELSTs and rescue workers in CS conditions.

Methods

The time required and success rate for IO infusion using a BIG in a manikin leg were measured, and for administering intravenous infusion in a manikin arm using either rescue gloves or plastic gloves by ELSTs or rescue workers under CS conditions.

Results

Wearing rescue gloves, ELSTs were significantly faster in placing intraosseous infusion (IOI) compared with rescue workers. The success rate of the placement was not significantly different between ELSTs and rescue workers whether or not they wore rescue or plastic gloves.

Conclusions

Although the finite usefulness of IOI with BIG under CS conditions is indicated, some problems such as the timing of removal of the IOI and difficulty in finding the location of the trocar needle after activating BIG are pointed out. Therefore, there are rooms to consider using IOI with BIG under CS condition. (Hong Kong j.emerg. med. 2014;21:23-30)

Histopathological and immunohistochemical evaluation of malignant potential in canine aortic body tumours

In order to verify the malignant potential of aortic body tumours (ABTs) in dogs, 13 cases of canine ABT were studied histopathologically and immunohistochemically. The cases were divided into two groups according to the presence or absence of metastases to other organs at necropsy examination (metastasis group [n = 9] and non-metastasis group [n = 4]). The mean tumour weight:body weight ratio (TW:BW; g/kg) in the metastasis group (9.3 ± 6.7) was significantly higher than that in the non-metastasis group (1.5 ± 1.7) (P <0.05). In both groups, the neoplastic cells had malignant features including pleomorphism, anisocytosis and anisokaryosis, and mononuclear giant cells were present, showing invasion through the capsule and into the vascular lumen and other adjacent tissues. The mitotic index (MI), mean nuclear area (NA) for size value and coefficient of variation of the nuclear area (CVNA) for anisonucleosis did not differ significantly between the two groups. These findings show that anaplastic characteristics are present regardless of the tumour size or the presence or absence of metastases, suggesting that these tumours are generally malignant or potentially malignant. Immunohistochemical analysis using neuroendocrine markers including neuron-specific enolase, chromogranin A and S100 revealed no obvious differences in labelling intensity of neoplastic cells related to the presence or absence of metastases or associated with the mean TW:BW, MI, NA or CVNA value, indicating that immunohistochemistry has no practical value for determining the tumour grade of canine ABTs.

Minocycline selectively inhibits M1 polarization of microglia

Minocycline is commonly used to inhibit microglial activation. It is widely accepted that activated microglia exert dual functions, that is, pro-inflammatory (M1) and anti-inflammatory (M2) functions. The in vivo status of activated microglia is probably on a continuum between these two extreme states. However, the mechanisms regulating microglial polarity remain elusive. Here, we addressed this question focusing on minocycline. We used SOD1^G93A mice as a model, which exhibit the motor neuron-specific neurodegenerative disease, amyotrophic lateral sclerosis. Administration of minocycline attenuated the induction of the expression of M1 microglia markers during the progressive phase, whereas it did not affect the transient enhancement of expression of M2 microglia markers during the early pathogenesis phase. This selective inhibitory effect was confirmed using primary cultured microglia stimulated by lipopolysaccharide (LPS) or interleukin (IL)-4, which induced M1 or M2 polarization, respectively. Furthermore, minocycline inhibited the upregulation of NF-κB in the LPS-stimulated primary cultured microglia and in the spinal cord of SOD1^G93A mice. On the other hand, IL-4 did not induce upregulation of NF-κB. This study indicates that minocycline selectively inhibits the microglia polarization to a proinflammatory state, and provides a basis for understanding pathogeneses of many diseases accompanied by microglial activation.

Compliance with Good Clinical Practice in oncology registration trials in Japan

BACKGROUND

This study aimed to examine the quality in oncology registration trials for new drug application (NDA) or supplemental new drug application (sNDA) as extensions of the indications for use in Japan based on Good Clinical Practice (GCP) audit findings.

MATERIALS AND METHODS

We collected audit reports of on-site GCP inspections for registration trials in 383 NDAs or sNDAs that were reviewed by the Pharmaceuticals and Medical Devices Agency between the fiscal years 2004 and 2009.

RESULTS

Among the 40 audits for oncology drug applications, the frequencies at which one or more deficiencies ascribed to institution, investigator, sponsor, and institutional review board were found to be 15 (37.5%), 13 (32.5%), 21 (52.5%), and 10 (25.0%), respectively. The exclusion of patients from the review objective due to serious violations of GCP in 40 audits for oncology drug applications was observed in 2 (5.0%) cases, whereas that in the remaining 343 audits for other drug applications was observed in 40 (11.7%) cases.

CONCLUSION

The overall compliance of GCP in oncology registration trials was moderately better than that in registration trials for other diseases, although there was no statistically significant difference between them.

Prediction of progressive disease using tumor markers in metastatic breast cancer patients without target lesions in first-line chemotherapy

BACKGROUND

The aim of this study was to develop a prediction model of progressive disease (PD) in breast cancer patients without measurable disease in first-line chemotherapy.

METHODS

We developed a model to predict PD using carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 15-3 in metastatic breast cancer patients who were enrolled in a phase III trial. The model was determined using the area under the receiver operating characteristic curve (AUC) calculated by the bootstrap method as internal validation. We verified the model for those who received first-line chemotherapy in a clinical setting as external validation. We categorized patients without measurable disease into PD and non-PD groups and compared the time to progression (TTP).

RESULTS

The model consisted of percent changes in CEA and CA 15-3 levels from second to third chemotherapy course and baseline abnormality of them. The AUC after external validation was 0.90. Patients without measurable disease were categorized into PD (N = 10) and non-PD groups (N = 53) by the model. The difference in TTP between the two groups was statistically significant (hazard ratio, 0.437; P = 0.021).

CONCLUSION

The model may be useful to determine PD in metastatic breast cancer patients without measurable disease.

Participation of elderly patients in registration trials for oncology drug applications in Japan

BACKGROUND

The objective of this study was to evaluate the age-based enrollment of cancer patients into registration trials of new drug applications or expanding the indications for use.

MATERIALS AND METHODS

The data from 234 registration trials in Japan and overseas of 43 drugs, which were reviewed by the Pharmaceuticals and Medical Devices Agency and approved by the Ministry of Health, Labour and Welfare in Japan between 1999 and 2008, were retrospectively analyzed according to the age distribution of enrolled patients. The age distribution of the Japanese cancer population was derived from Cancer Statistics in Japan 2003 and Annual Report on Health, Labour and Welfare 2003-2004.

RESULTS

In the Japanese cancer population, the estimated median age of cancer patients is 70 years, and 66% of cancer patients are aged 65 years or more. The estimated median age of cancer patients in all registration trials conducted in Japan was 59 years, whereas it was 55 years in the registration trials conducted overseas. The proportion of patients aged 65 years or more enrolled in registration trials conducted in Japan was 35%; this number was 28% in registration trials conducted overseas.

CONCLUSION

Elderly patients are underrepresented in oncology registration trials in Japan.

Irinotecan plus carboplatin for patients with carcinoma of unknown primary site

Carcinoma of unknown primary site (CUP) is rarely encountered in clinical practice and optimal chemotherapy has not yet been established. This phase II study was conducted to evaluate the efficacy and toxicity of combined irinotecan+carboplatin therapy in chemotherapy-naive patients with CUP. Irinotecan was administered at 60 mg m(-2) as a 90-min intravenous infusion on days 1, 8 and 15. Carboplatin was administered at an area-under-the curve of 5 mg ml(-1) min as a 60-min intravenous infusion on day 1. This cycle was repeated every 28 days for up to six cycles. Forty-five patients were enrolled in the study. An intent-to-treat analysis revealed an objective response rate to the treatment of 41.9% (95% confidence interval, 27.0-57.9%). The median time to progression was 4.8 months and the median survival was 12.2 months. The 1- and 2-year survival rates were 44 and 27%, respectively. The most frequent grade 3 or more severe adverse events were leukopaenia (21%), neutropaenia (33%), anaemia (25%) and thrombocytopaenia (20%). Thus, the combination of irinotecan plus carboplatin was found to be active in patients with CUP. Therefore, the regimen may be one of the potentially available chemotherapeutic options for community standard of care in patients with a good performance status.

Role of the mitochondrial permeability transition and cytochrome C release in hydrogen peroxide-induced apoptosis

We investigated the role of the mitochondrial inner membrane permeability transition and subsequent release of cytochrome c into the cytosol during oxidative stress-evoked apoptosis. Sublethal oxidative stress was applied by treating L929 cells with 0.5 mM H2O2 for 90 min. Then the cellular localization of cytochrome c was examined by immunofluorescent staining and Western blotting. H2O2 treatment caused the permeability transition and pore formation, resulting in membrane depolarization and translocation of cytochrome c from the mitochondria into the cytosol. Pretreatment with cyclosporin A and aristolochic acid (to inhibit pore formation) significantly attenuated a reduction of the mitochondrial membrane potential, as well as signs of apoptosis such as DNA fragmentation, increased plasma membrane permeability, and chromatin condensation. Therefore, exposure to H2O2 caused the opening of permeability transition pores in the inner mitochondrial membrane. An essential role of cytosolic cytochrome c in the execution of apoptosis was demonstrated by its direct microinjection into the cytosol, thus bypassing the need for cytochrome c release from the mitochondrial intermembrane space. Microinjection of cytochrome c caused caspase-dependent apoptosis.

Hypertension and impairment of endothelium-dependent relaxation of arteries from spontaneously hypertensive and L-NAME-treated Wistar rats

Effects of chronic treatment of normotensive Wistar rats with N(omega)-nitro-L-arginine methyl ester (L-NAME) on blood pressure and on endothelium-dependent relaxation of the aorta, carotid and iliac arteries were studied. The endothelium-dependent relaxation was compared in arteries from normotensive Wistar Kyoto rats (WKY) and genetically hypertensive rats (stroke-prone spontaneously hypertensive rats, SHRSP). Chronic treatment of normotensive Wistar rats with L-NAME caused an elevation of blood pressure. The elevated blood pressure at 15 weeks of age was significantly higher in these animals than that of untreated Wistar rats, but lower than that of SHRSP. Endothelium-dependent relaxation of the arteries induced by acetylcholine (ACh) was almost abolished by chronic treatment with L-NAME. The remaining small relaxation in arteries from L-NAME-treated rats was completely inhibited by application of L-NAME (10(-4) M). In such preparations, higher concentrations of ACh induced a contraction, which was abolished by removal of the endothelium or by an application of indomethacin (10(-5) M). Endothelium-independent relaxation induced by sodium nitroprusside was similar between preparations from untreated and L-NAME-treated Wistar rats. Endothelium-dependent relaxation was significantly impaired in preparations from SHRSP, when compared with that in those from WKY. However, the impairment was less prominent in preparations from SHRSP than in those from L-NAME-treated rats. These results suggest that the impairment of endothelium-dependent relaxation in the arteries from L-NAME-treated rats is not due to the elevated blood pressure resulting from the chronic treatment, and that impairment of NO synthesis by the endothelium does not play a major role in the initiation of hypertension in SHRSP.

Evaluation of pulmonary vasodilatory capacity with inhaled nitric oxide in a dog with patent ductus arteriosus

A female Maltese dog with patent ductus arteriosus (PDA) showing left congestive heart failure and moderate pulmonary hypertension was evaluated for pulmonary vasodilatory capacity using low concentrations of inhaled nitric oxide (NO) in comparison with oxygen during preoperative cardiac catheterization. Increasing the inspired oxygen concentration (FiO2) to 1.0 without adding NO did not reduce the mean pulmonary arterial pressure (mPAP). However, inhalation of NO at FiO2 1.0 reduced mPAP rapidly without changing other hemodynamic and gas exchange parameters. From these results, inhaled NO caused selective pulmonary vasodilation without producing systemic vasodilation, which may provide a safe and effective mean of evaluating the pulmonary vasodilatory capacity of dogs with PDA.

Effects of inhaled nitric oxide on hypoxic pulmonary vasoconstriction in dogs and a case report of venae cavae syndrome

We investigated the effect of inhaled nitric oxide (NO) on hypoxic pulmonary vasoconstriction (HPV) in dogs, by treating a dog suffering from venae cavea syndrome (VCS) and pulmonary hypertension (PH) with NO inhalation. The increasing mean pulmonary arterial pressure (mPAP) induced by hypoxia was lessened significantly by NO inhalation. High PAP in VCS also declined as a result of NO inhalation. These results suggested that inhaled NO can reverse HPV in dogs and prevent worsening PH during surgical extraction of heartworm in VCS.

Effect of positive end-expiratory pressure on extravascular lung water and cardiopulmonary function in dogs with experimental severe hydrostatic pulmonary edema

The effects of ventilation at positive end-expiratory pressure (PEEP) on extravascular lung water (EVLW) and cardiopulmonary function were studied in dogs with experimental severe hydrostatic pulmonary edema, which was generated by inflating a left atrial balloon and simultaneously injecting warm 5% glucose solution into the pulmonary artery. The EVLW was measured by the double indicator dilution method using heat and sodium ions. All the dogs were ventilated at zero end-expiratory pressure (ZEEP) until the EVLW had increased by 200-300% (maximal edema), when they were divided into two groups, one of which (n = 6) was ventilated at a PEEP of 10 cm H2O throughout the 4 hr study period (PEEP group) and the other (n = 6) was maintained at ZEEP during their survival period (ZEEP group). All the dogs in the PEEP group survived ventilation for 4 hr, whereas all those in the ZEEP group died within 3 hr, (2 within 1 hr, 1 between 1 and 2 hr and 3 between 2 and 3 hr). The EVLW of the PEEP group remained unchanged throughout the 4 hr study period, whereas that of the ZEEP group showed a tendency to increase. The arterial oxygen tension (PaO2) increased significantly throughout the 4 hr period of ventilation in the PEEP group but tended to decrease in the ZEEP group. In conclusion, PEEP improves gaseous exchange, but does not decrease the EVLW in dogs with experimental severe hydrostatic edema.

Principal component analysis, using the measurements during running and swimming test, in thoroughbred horses

To investigate whether the running exercise fitness of individual horses could be assessed by a standardized swimming exercise test, the results of multivariate analysis of the exercise parameters measured during incremental running and swimming tests were compared. Ten thoroughbred horses were subjected to different types of exercise tests on a track or in a pool, and the maximum heart rate during and the blood lactate concentration immediately after the exercise were examined. Serial exercise parameters (VLA2, VLA4, LA0, V150, V200, HRS, HRLA2, HRLA4) referred to as the indices related to the adaptation of cardiovascular or metabolic systems were computed using the relationships between these measurements and velocity during each test, and were analyzed by a multivariate procedure, i.e. the principal component analysis. The correlation diagram between the exercise parameters on the first two component axes in running were similar to that in swimming. When the exercise fitness in each horse was compared between running and swimming, three horses trained by short-term endurance exercise were statistically distinguished in both tests and differed as a group from the other horses. Therefore, it is thought that evaluation of the exercise fitness in swimming using the multivariate analysis is useful for predicting poor performing horses on a track.