Feeding induced by pharmacological blockade of fatty acid metabolism is selectively attenuated by hindbrain injections of the galanin receptor antagonist, M40

Distal transcutaneous oxygen pressure measurement (TcPo2) is a noninvasive method of evaluating tissular hypoxemia in peripheral arterial disease. The poststress area of hypoxemia is a usefull technique for globally quantifying different parameters represented by TcPo2 curves during exercise. Although its use is increasingly widespread, the reproducibility of this method is poorly documented. TcPo2 was monitored three times at twenty-four hour intervals in 5 patients with stage II obliterative arterial disease during a treadmill walking test. In order to get uniform measurement conditions, each patient remained lying and then stood until TcPo2 became stable. The stress duration was calculated so that the pain step could not be reached. TcPo2 curves were digitized and a specific image analyzer was used to make replicate measurements. The area under the curve was computed, the horizontal axis determining the mean TcPo2 value at rest, the vertical axis representing the end of the exercise period. The corresponding areas under the curves ranged from 34 to 2212 mm2 (573.60; SD 826). Significant correlation coefficients were obtained among replicate measurements (first-second day, first-third day). However, owing to the wide range of area values, the authors decided to compute and use the coefficient of variation (STD/mean), since it was more representative of reproducibility. The mean of its value for 5 patients was 21%. Observation of the examination conditions resulted in several findings, especially the ability of certain patients to adapt their efforts to the exercise. These results indicate that TcPo2 poststress area measurements are reproducible, but the conditions of the exercise have to be rigorously defined and may still be improved.     

Development of seven new human prostate tumor xenograft models and their histopathological characterization

Seven human prostate tumor models were established by transplanting tumor fragments in NMRI athymic nude mice. Once established, the tumors were serially transplantable in both NMRI and BALB/c nude mice. The xenografts originated from primary prostatic carcinomas (prostatectomy specimens), transurethral resection material, and metastatic lesions (pelvic lymph nodes and scrotal skin). Histological examination revealed that, in the course of several mouse passages (8 to 23), tumors retained their resemblance to the original patient material. The PC-295, PC-310, PC-329, and PC-346 tumors are dependent on androgens for their growth. The PC-324, PC-339, and PC-374 tumors are androgen independent, although growth of PC-374 tumors still seemed androgen sensitive. All tumors are diploid, except for the PC-374, which is tetraploid. The diploid PC-295 tumor has an additional small population of tetraploid cells. All xenografts displayed a heterogeneous expression pattern of the androgen receptor except for the PC-324 and PC-339 tumors in which the androgen receptor could not be detected. Prostatic acid phosphatase and prostate-specific antigen were retained during serial transplantation in all tumors but the PC-324 and PC-339. This panel of permanent human prostate tumor models comprises tumors representing both the androgen-dependent and -independent stages of human prostate cancer with various degrees of differentiation and, therefore, is of great value for the study of many aspects of growth and progression of human prostate cancer.     

Pathological and immunocytochemical changes in chronic calcium oxalate nephrolithiasis in the rat

In the present study, we exposed rats to a crystal-inducing diet (CID) consisting of vitamin D3 and 0.5% ethylene glycol (EG), and we investigated histologically the kidney damage induced by the deposition of calcium oxalate (CaOx) crystals. After 28 days, 50% of the animals had renal CaOx crystals, of which 60% also had small papillary stones. Most crystals were present in the cortex. The occurrence of these crystals coincided with morphological and cytochemical changes: glomerular damage, tubular dilatation and necrosis, and an enlargement of the interstitium. The number of epithelial and interstitial cells positive for the proliferating cell nuclear antigen (PCNA) was increased. Tamm-Horsfall protein (THP) was not only demonstrable in the thick ascending limb of the loop of Henle (TAL), but also frequently in glomeruli, in the proximal tubular epithelium, and in the papilla. In the lumen of the tubular system, it was associated with urinary casts. Reflection contrast microscopy (RCM) showed that the crystals were coated with a thin layer of THP. In spite of the high urinary oxalate concentrations, the above described cellular changes were not observed in CID-fed rats without renal crystals. We conclude, therefore, that in the kidney, the retained CaOx crystals rather than the urinary oxalate ions are responsible for the observed morphological and immunocytochemical changes.     

Device to limit inflation of a pulmonary artery catheter balloon

OBJECTIVE: The most serious complication seen with pulmonary artery catheters is rupture of the pulmonary artery. The effectiveness of an external safety balloon added to the pulmonary artery balloon inflation port was tested. DESIGN: The external balloon is designed to inflate and absorb excess volume from the inflation syringe after the internal balloon contacts the vessel wall. When the catheter tip is in a small pulmonary artery, expansion of the external balloon indicates that the catheter tip is in a noncompliant or small vessel. SETTING: The external balloon was tested in a bench simulation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The pulmonary artery balloon was slowly inflated inside 2.6-, 3.0-, 4.7-, 8.6-, and 11.6-mm internal diameter polyvinyl chloride tubes, with and without the external safety device in place. Without the external balloon, the average balloon pressure was 1647 +/- 145 (SD) mm Hg in the 2.6-mm vessel. With the external balloon in use, the maximum pulmonary artery balloon pressure was 473 +/- 7.2 mm Hg in the 2.6-mm vessel. CONCLUSIONS: The external balloon can limit balloon pressures within the pulmonary artery and identify when excessive volumes are being forced into the pulmonary artery balloon.     

Anterior cruciate ligament reconstruction: endoscopic versus two-incision technique

The purpose of this study was to compare the single-incision, "endoscopic" (ENDO) anterior cruciate ligament (ACL) reconstruction technique with the two-incision, "rear-entry" technique (RE). Sixty patients were entered into a prospective study. Thirty patients underwent ACL reconstruction by the RE technique, followed by 30 consecutive patients using the ENDO procedure. Postoperatively all patients followed a standardized rehabilitation protocol. Follow-up evaluation consisted of a detailed physical examination, range of motion, thigh girth, vertical leap, hop test, KT-1000 testing, and patient interview. They were scored according to the International Knee Documentation Committee (IKDC) protocol, which takes objective and subjective data into account. Patients were also assessed for level of sports activity including frequency and type. Finally, anteroposterior and lateral x-ray films were evaluated with a scoring system for tunnel location. Of the initial 60 patients entered into the study, 50 were available for a detailed clinical and functional review (83%). Demographic comparisons revealed 24 RE patients and 26 ENDO patients. There were 16 men and 8 women in the RE group. The ENDO group comprised 16 men and 10 women. There were 14 right knees and 10 left knees in the RE group. In the ENDO group there were 13 right knees and 13 left knees. The average age in the RE group was 24 years and 25 years in the ENDO group. The average follow-up was 35 months (range 31-40 months) in the RE group and 29 months (range 24-35 months) in the ENDO group. Complications included two patients with loss of motion in the RE group and three in the ENDO group. There were no significant differences between the two groups tested with respect to the overall IKDC rating scale. Anteroposterior and lateral x-ray films revealed no significant differences in femoral and tibial tunnel placement. In conclusion, no significant functional or radiographic differences at a minimum 2-year follow-up could be identified when comparing the two ACL reconstructive techniques.     

Gastroduodenal resistance and neural mechanisms involved in saline flow decrease elicited by acute blood volume expansion in anesthetized rats

We have previously demonstrated that blood volume (BV) expansion decreases saline flow through the gastroduodenal (GD) segment in anesthetized rats (Xavier-Neto J, dos Santos AA & Rola FH (1990) Gut, 31: 1006-1010). The present study attempts to identify the site(s) of resistance and neural mechanisms involved in this phenomenon. Male Wistar rats (N = 97, 200-300 g) were surgically manipulated to create four gut circuits: GD, gastric, pyloric and duodenal. These circuits were perfused under barostatically controlled pressure (4 cmH2O). Steady-state changes in flow were taken to reflect modifications in circuit resistances during three periods of time: normovolemic control (20 min), expansion (10-15 min), and expanded (30 min). Perfusion flow rates did not change in normovolemic control animals over a period of 60 min. BV expansion (Ringer bicarbonate, 1 ml/min up to 5% body weight) significantly (P < 0.05) reduced perfusion flow in the GD (10.3 +/- 0.5 to 7.6 +/- 0.6 ml/min), pyloric (9.0 +/- 0.6 to 5.6 +/- 1.2 ml/min) and duodenal (10.8 +/- 0.4 to 9.0 +/- 0.6 ml/min) circuits, but not in the gastric circuit (11.9 +/- 0.4 to 10.4 +/- 0.6 ml/min). Prazosin (1 mg/kg) and yohimbine (3 mg/kg) prevented the expansion effect on the duodenal but not on the pyloric circuit. Bilateral cervical vagotomy prevented the expansion effect on the pylorus during the expansion but not during the expanded period and had no effect on the duodenum. Atropine (0.5 mg/kg), hexamethonium (10 mg/kg) and propranolol (2 mg/kg) were ineffective on both circuits. These results indicate that 1) BV expansion increases the GD resistance to liquid flow, 2) pylorus and duodenum are important sites of resistance, and, 3) yohimbine and prazosin prevented the increase in duodenal resistance and vagotomy prevented it partially in the pylorus.     

A computer-based method for cause of death classification in stillbirths and neonatal deaths

BACKGROUND: In large-scale epidemiological studies of stillbirths and neonatal deaths a method is needed to replace detailed medical record audits in order to determine the cause of death. METHODS: A computer-based method is presented for determination of the cause of death in stillbirths and in neonatal deaths. It utilizes information in the Swedish medical registries. The study comprises 6044 dead infants born in Sweden from 1983-1990. For each infant the program determines 31 basic characteristics which are important in deciding the cause of death. Based on these characteristics a modified Wigglesworth's classification is used to find the cause of death. The validity of the method was checked by comparing the computer generated information with information obtained by scrutinizing medical records for a 10% representative sample (603 infants). RESULTS: Specificity and sensitivity for each basic characteristic varied, but for the modified Wigglesworth cause of death classification the concordance was 88%. The weakest data refer to intrauterine deaths, where pertinent information was often missing in the medical registries. CONCLUSION: The method can be used for large-scale epidemiological studies.     

Experimental leukocyte-induced pulmonary vasculitis with inquiry into mechanism

Intravenous transfusions of washed allogeneic or autologous leukocytes in rabbits resulted in lesions of pulmonary periarteritis 48 hours later. Intact leukocytes were required. Systemic anaphylaxis, generalized Shwartzman reaction, alternate pathway complement activation and inert particle microembolism failed to produce identical lesions. Leukocytes tagged with radioactive chromium were found within arterial thromboses with proximal vasculitis. Generation or release of inflammatory factors plus thromboembolism would explain the pathogenesis of the lesions described. Specific mechanisms may be quite complex. Similar lesions have not been described in studies of pulmonary leukocyte entrapment or experimental microembolism of the lung. This model may be useful for studying pathogenetic mechanisms in pulmonary vasculitis and may have clinical implications.