Effects of partial hepatectomy on organ-specific toxic response to 1,2-dibromo-3-chloropropane (DBCP)

The organ-specific toxic potency of subcutaneously administered 1,2-dibromo-3-chloropropane (DBCP) was compared in partially hepatectomized and sham-operated rats over a dose range of 20--80 mg kg-1 to assess the roles of hepatic and extrahepatic metabolism in protection against acute renal and gonadal injury. Relative kidney weight and the severity of DBCP-induced renal proximal tubular cell necrosis were increased in rats subjected to a partial (70%) surgical hepatectomy 48 h prior to treatment with DBCP at 80 mg kg-1. Relative liver weight was reduced by DBCP in the hepatectomized, but not in the sham-operated rats. The severity of DBCP-induced (80 mg kg-1) hepatocellular centrilobular necrosis was greater in hepatectomized than in sham rats. DBCP reduced the relative weights of the testis and epididymis in a progressive manner and produced dose-dependent seminiferous tubular atrophy within 12 days of treatment. The morphologically apparent lesions of the testis and epididymis were enhanced by hepatectomy. The concentration of non-protein sulfhydryl groups (NPS) in rat liver was increased by partial hepatectomy. Because of the resulting decrease in liver size, however, the total amount of hepatic NPS per kg body weight 48 h post-surgery was lower than in sham rats. The surgery had no effect on renal, testicular or epididymal NPS concentrations of organ weights. Partial hepatectomy greatly increased pentobarbital and ethanol sleeping times, while sleep induction time for pentobarbital was decreased.(ABSTRACT TRUNCATED AT 250 WORDS)     

HLA-DR typing in identical twins with insulin-dependent diabetes: difference between concordant and discordant pairs

A total of 106 pairs of identical twins, of whom 56 were concordant and 50 discordant for insulin-dependent diabetes, were typed for HLA-DR. In both the concordant and discordant groups there was a high prevalence of the antigens DR3 and DR4, a low prevalence of DR5 and DR7, and a virtual absence of DR2. The heterozygous phenotype DR3,DR4 was more prevalent in concordant than discordant pairs. This was therefore the first demonstration of a genetic difference between concordant and discordant identical twin pairs. These findings suggest that possession of both DR3 and DR4 antigens confers a greater genetic predisposition to insulin-dependent diabetes than does the possession of either antigen alone.     

Distribution of organic matrix in calcium oxalate renal calculi

Summary The quantity of protein and carbohydrate comprising the matrix of calcium oxalate monohydrate (COM) renal stones was found to decrease with distance from the surface of the stone. The average organic concentration of stones 3 to 30 mm in diameter ranged from 5.7% at the surface to 2.7% at the core. This concentration gradient suggests matrix involvement in a “growth front” on stone surfaces with migration of organic material from the “older” interior. The matrix distribution was not readily correlated with density variations or with the presence of hydroxyapatite or calcium oxalate dihydrate. Surface matrix concentrations were greater than amounts predicted by physical adsorption. Electron microscopy confirmed the presence of the organic-rich surface layer and also suggested that increase in stone size occurs predominantly by crystal growth with microcrystal aggregates as growth centers.     

MR imaging of the labral-capsular complex: normal variations

Understanding the normal anatomy of the shoulder and its variations is important for the proper interpretation of MR images. This study was performed to describe variations in the normal labral-capsular complex as seen on MR images. MR images of 52 shoulders in 30 asymptomatic volunteers and 27 shoulders of symptomatic patients who had subsequent arthroscopy and/or reconstructive surgery were obtained with 1.5-T MR. The 52 scans of the asymptomatic group were reviewed by three radiologists in conference, and the assessment of labral shapes and capsular insertions was done by consensus. The 27 MR scans of the shoulders in the symptomatic group were reviewed by one radiologist before and after the asymptomatic cases were interpreted. Differences in these two interpretations were shown on receiver-operating-characteristic curves by using the results of subsequent arthroscopy and surgery as the gold standard. The anterior and posterior parts of the labra, respectively, varied in shape but showed several dominant features: triangular (45%, 73%), round (19%, 12%), cleaved (15%, 0%), notched (8%, 0%), flat (7%, 6%), and absent (6%, 8%). Most capsules inserted anteriorly on the labrum (47%) or glenoid rim (49%). All posterior insertions were on the labrum (100%). Intrinsic labral signal was noted on proton density-weighted images, but never on T2-weighted images. Receiver-operating-characteristic curves from interpretations of the symptomatic and clinical cases made before and after evaluation of the asymptomatic shoulders showed the interpretations improved considerably after scans of asymptomatic volunteers were studied. Our study reveals a wide variability in the MR appearance of the labral-capsular complex in asymptomatic shoulders.     

Hemangioma of the nasal vault: MR and CT features

Six patients with a history of epistaxis (five patients) or nasal obstruction (one patient) were found to have a capillary hemangioma of the nasal vault that involved one or more nasal turbinates. Four patients underwent computed tomographic (CT) examination; two of these also underwent magnetic resonance (MR) imaging. Four others underwent only MR imaging. At CT and MR, all of the lesions were well circumscribed and intensely enhancing, with contralateral deviation of the nasal septum. Remodeling of the surrounding bone was present in three patients. On T1-weighted MR images, the masses were intermediate in signal intensity. Varying degrees of T2 shortening were shown on T2-weighted MR images, with an appearance that suggested the presence of blood products surrounding an inner matrix of higher-signal-intensity tumor. Intense enhancement at CT and MR assisted differentiation of tumor from retained sinonasal secretions. In two patients, external carotid arteriography revealed small foci of pooling contrast material; in one of these patients, arteriovenous shunting was also present. Pathologic examination in all patients demonstrated capillary hemangiomas with varying degrees of fibrosis and hemosiderin deposition.     

Sphincter injury after anal dilatation demonstrated by anal endosonography.

Anal dilatation is still used in the treatment of anal fissure and haemorrhoids. Using anorectal physiology and anal endosonography we have studied 12 men presenting with faecal incontinence following anal dilatation. Resting anal pressures were low, pudendal nerve latencies were normal; 11 men had a disrupted internal anal sphincter and in ten this was extensively fragmented. Three also had defects of the external anal sphincter. These findings demonstrate for the first time the nature of the structural injury which may be caused by anal dilatation.     

The brain/mind complex. An epistemological approach.

It is stressed that the brain/mind complex constitutes a monolithic system that functions with emergent properties at several levels of hierarchical organization. These hierarchical levels are non-reducible to one another; they are at least three (neuronal, functional, and semantic), and they function within an interactional plan. From the epistemological view-point, the brain/mind complex uses logical and non-logical mechanisms to deal with day-to-day problems. Logic is necessary for the thinking process, but it is not sufficient. Emphasis is given to non-logical mechanisms; fuzzy logic and heuristics, which allow the mind to develop strategies to find solutions, are analysed.     

Protein-calorie malnutrition impairs host defense against Candida albicans.

Protein-calorie malnutrition (PCM) impairs immune responsiveness predisposing to Candida albicans sepsis, but mechanisms are unclear. This study examined the effect of PCM on enteric-derived C. albicans intestinal translocation and the ability of in vivo interferon-gamma (IFN-gamma) to upregulate macrophage (MO) candidacidal mechanisms in PCM mice. Control (24% casein) and low protein (2.5%) diets were given for 4 weeks. Mice (n = 160) were fed C. albicans in their drinking water for 3 days and C. albicans translocation (mean colony-forming units (CFU)/g tissue +/- SEM) to the GI tract, liver, spleen, and kidney was assessed at 1 and 5 days following endotoxin challenge of 1, 5, and 10 mg/kg body wt. In a separate study (n = 100 mice), IFN-gamma (1000-10,000 U/day ip) vs saline was given for 3 days prior to harvesting peritoneal macrophages for assay of superoxide anion (O2-), percentage macrophage phagocytosis of C. albicans, and percentage killing of C. albicans. On Day 1, fungal translocation to the intestinal wall and systemic organs in the PCM group was significantly higher. On Day 5, mean CFU were significantly higher in the PCM group, indicating impaired organ clearance. Mean O2-, phagocytosis, and killing were significantly impaired in the PCM group (P less than 0.05), but IFN-gamma improved all functions. PCM significantly depressed host responses to C. albicans. IFN-gamma treatment enhanced candidacidal mechanisms, suggesting a therapeutic role in the malnourished host predisposed to C. albicans sepsis.     

The effect of sodium fluoride on trabecular architecture.

The effect of sodium fluoride therapy on iliac trabecular bone has been studied in 15 patients with primary osteoporosis by comparing bone biopsies taken before and after two years of treatment. A marked increase in bone volume (43%) was observed, which was attributable to an increase in trabecular thickness (46%) rather than their number. Because the trabecular bone surface, the trabecular number, the bone volume/trabecular width ratio, and the trabecular terminus number do not change significantly after fluoride treatment, we conclude that fluoride does not induce the de novo generation of trabeculae, nor does it restore trabecular connectivity despite the restoration of bone mass. These data suggest that the restoration of skeletal mass with fluoride may not lead to a comparable decrease in the risk of future fracture.     

Studies of pickled vegetables and cause of esophageal cancer in Linxian. II. Determination of nitrosamines and their precursors]

Pickled vegetables are daily food consumed in the high-risk areas for esophageal cancer in China. We analyzed the nitrosamine content of Linxian pickles by GC/TEA and found that trace amounts of six nitrosamines (NDMA, NDEA, NMBA, NMAMBA, NDPA, NPYR) were present, with the highest concentrations being NDMA and NDEA (1.7 and 1.9 micrograms/kg wet weight respectively). The average level of nitrosamine precursors, such as nitrate (111.22 mg/L), nitrite (0.152 mg/L) and secondary amines (4.223 mg/L), in pickled vegetables were determined, and their pH values ranged from 3 to 5.