摘要:

Recent studies have supported the possibility that mechanisms other than alterations in transcapillary oncotic pressure may contribute to edema formation in nephrotic syndrome. In a patient with a discrete, partial obstruction to lymphatic flow in the left upper extremity, the authors determined the transcapillary oncotic pressure differential in the obstructed, more edematous extremity and the contralateral, unobstructed extremity. The results demonstrate a normal transcapillary oncotic pressure gradient in the unobstructed extremity, while in contrast, the gradient in the obstructed extremity, was reduced. Clinically, the edema resolved completely in conjunction with resolution of the nephrotic syndrome. The authors conclude, therefore, that the obstructed extremity may be more susceptible to edema formation because of inability to increase lymphatic flow during periods of hypoalbuminemia to levels sufficient to reduce the interstitial oncotic pressure gradient. Furthermore, the normal gradient in the unobstructed extremity supports the view that other mechanisms, such as intrinsic alterations in renal sodium reabsorption, may be involved in edema formation because edema was present without demonstrable alterations in the transcapillary oncotic pressure differential and plasma volume was increased in this patient.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The present study investigated the integrity of the rat gastric mucosa after 6 hours of vagotomy without drainage. Transection vagotomy was employed to ensure complete gastric vagal denervation. Vagotomy without drainage produced gastric distension and mucosal injury confined to the glandular part. Anterior truncal vagotomy produced in jury in 70% of rats, whereas truncal or transection vagotomy produced injury in all rats. The injury score with transection vagotomy was significantly higher than that with anterior truncal (21.2mm2± 1.6 vs. 8 mm2± 2.7, mean ± SEM, n = 10, p <.05). Histologic examination of the mucosal injury revealed necrosis involving the epithelium and lamina propria. Cholestyramine, pyloroplasty, or gastrtric diversion protected the stomach against the vagotomy-in-duced mucosal injury. The results demonstrate in the rat that vagotomy without drainage produces within 6 hours injury of the gastric mucosa, which increases as vagal denervation is rendered more complete. Because cholestyramine protects the rat stomach against vagotomy-induced acute gastric mucosal injury, reflux of duodenal contents appears to be the principal factor behind this injury. Pyloroplasty prevents gastric distension but probably not duodenal contents refluxing, suggesting that this distention also may have a role in the mechanism of the said injury.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Various studies have shown that a high protein (HP) diet, compared to a low protein (LP) diet, leads to hypercalciuria and alterations in renal and systemic hemodynamics. The authors compared the effects of HP diet to those of normal protein diet (NP) to determine the possible mechanisms by which changes in systemic hemodynamics and hypercalciuria occurred. The studies were conducted in awake rats; the effects of dietary sodium content on the changes induced by HP also were evaluated. The relationship of prostaglandins (PG), renin (PRA), and aldosterone (PA) to changes in blood pressure (BP) was assessed. Two weeks after HP and normal sodium feeding (40%), glomerular filtration rate (GFR) and urine flow (V) were not different from the same values in a group on an NP diet (23%). When HP was fed with low sodium, there was a rise in V as a consequence of greater fluid intake. Although plasma calcium remained constant, the hypercalciuria correlated with high protein and sodium content. Alterations in 1,25 (OH)2vitamin D3 or PTH (cyclic AMP exeretion) function did not explain the hypercalciuria induced by HP. This suggests that HP leads to inhibition of tubular calcium reabsorption by mechanism(s) yet to be elucidated. Although HP did not alter GFR, it led to an increase in BP, a fall in renal vascular resistance, and an increase in RPF, regardless of sodium intake. PRA and urine PGE2excretion were significantly higher in the rats on HP diet, whereas PA remained unchanged. The results suggest that elevation of PRA by HP feeding of 2 weeks' duration in young, awake rats may be mediated by increased renal PG's production. The studies also suggest that BP elevation induced by HP may be related to increased renin secretion.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Changes in self-reported functional status during pregnancy were studied in 100 women. The baseline interview at 20 weeks was used for assessing subsequent change in maximal physical mental, and emotional function as well as in global function and global sense of health. although the transition instruments were only tested at three points during pregnancy (30, 35, and 40 weeks), they succeeded in detecting changes. In particular, both maximal physical function and global function tended to deteriorat as pregnancy progressed toward term, although few women considered themselves to be sick. The authors suggest that changes in functional status should be considered an important “outcome” of pregnancy. Patient-specific measures of change in self-reported maximal function might be used in future trials to help assess the impact of interventions on individual patient's maximal function. The timing of the baseline interview and frequency of the transition assessments should depend on the specific clinical problem under study.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

First trimester prenatal diagnosis of I-cell disease (1 case) was based on demonstration of profound deficiency of N-acetylglucosamine 1-phosphotransferase in chorionic villi and in cultured trophoblasts derived from the chorionic villus specimen. Deficiency of this enzyme in cultured amniotic fluid cells obtained via amniocentesis was the basis for prenatal diagnosis of I-cell disease in the second trimester (2 cases). In both procedures, the diagnosis was corroborated by the finding of intracellular deficiency and extracellular elevation of multiple lysosomal enzymes in the fetal cell cultures (trophoblasts and amniotic fluid cells), as well as a significant increase in several lysosomal enzyme activities in the maternal serum.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The authors describe the abnormalities of gonadal function developing in a patient with prostate cancer who had received estrogen therapy continuously for 6 years. The pretreatment prostate biopsy showed well developed acini consistent with normal androgenization and adenocarcinoma. Twelve years later, 6 years after discontinuation of estrogen treatment, the patient presented with severe hypogonadism, gynecomastia, and primary hypothyroidism. Testicular biopsies showed ghosts of seminiferous tubules with absence of Leydig cells, and prostatic biopsies showed atrophic acini without evidence of malignancy. Despite undetectable serum testosterone levels, serum gonadotropins were inappropriately normal and responded minimally to gonadotropin-releasing hormone (GnRH) administration. Replacement therapy with levothyroxine did not correct gonadal dysfunction. Thus, prolonged estrogen therapy may result in irreversible testicular destruction and loss of the feed-back response of the hypothalamic pituitary gonadal axis.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Ranitidine, and H2receptor antagonist, has been associated with hematotoxicity. The mechanism(s) underlying this toxicity is not well understood. The authors studied the mechanism of anemia in a patient with ranitidine associated anemia and thrombocytopenia. Clinical evaluation suggested drug-induced Coombs' positive reticulocytopenic hemolysis. In vitro, with the patient off ranitidine, the authors were able to induce Coombs' positivity by incubating patient's red cells with ranitidine and his serum. This process was inhibited by prior exposure of his red cells to histamine. In vitro studies using clonal assays for hematopoietic progenitors revealed that while the patient's serum or ranitidine alone did not affect the patient's or normal bone marrow hematopoiesis, the simultaneous presence of both agents significantly suppressed both patient's and normal erythroid progenitor (BFU-E) colony development. This suppressive effect was prevented by the prior exposure of marrow to histamine and was not observed when the patient's serum was heat inactivated. These studies suggest that the anemia may have resulted from complement-dependent autoimmune destruction/inhibition of progenitor/mature erythroid cells by a process critically dependent on the presence of ranitidine and possibly acting at or near the histamine receptor.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

The streptozotocin diabetic rat (STZ-DM) has been the best animal model for the study of insulin-deficient diabetes. A spontaneous diabetic BB Wistar Rat (SDR) has now been evaluated as a model for insulin-dependent diabetes that more closely reflects this disease in humans. The authors assessed the ability of insulin to stimulate the Vmax of a low Km cAMP phosphodiesterase (PDE) in adipose tissue of control, streptozotocin diabetic (STZ-DM) rats, and spontaneous diabetic BB rats (SDR). In addition, the authors examined the effect of streptozotocin on the nondiabetic littermates of the SDR animal, the NDR rat. Insulin stimulated Vmax of low Km cAMP phosphodiesterse (PDE) in adipose tissue of control, streptozotocin diabetic (STZ-DM) rats, and spontaneous diabetic BB rats (SDR). In addition, the authors examined the effect of streptozotocin on the nondiabetic littermates of the SDR animal, the NDR rat. Insulin stimulated Vmax of low km cAMP PDE in control rat adipose tissue by 20% at 5 minutes. Insulin also stimulated Vmax of both SDR and NDR by 50% at 5 minutes. In contrast to control and both subgroups of the BB rat (SDR and NDR), Insulin stimulated adipose tissue from STZ-DM less than 10% at 5 minutes. NDR animals rendered diabetic with streptozotocin were more responsive to insulin. The data demonstrate some similarities and differences between Streptozotocin-induced diabetes and spontaneous diabetes in the BB rat. Reduced responsiveness to insulin appears to be more a part characteristic of streptozotocin diabetes than diabetes in the BB rat. The absence of significant insulin resistance in the spontaneous diabetic BB rat also is more consistent with the pathophysiological mechanisms usually seem both in other insulin-dependent diabetic rat models and insulin-dependent diabetes in man. However, both animal models of diabetes, ie, STZ-DM and BB, like man, respond to insulin therapy.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

Bacterial respiratory infections are common in patients undergoing prolonged mechanical ventilation, and antibiotic selection often is based upon the results of smears and cultures of tracheal aspirates (TA). This study was designed to determine the reliability of gram stains, cultures and antibody-coating of bacteria in TA by comparing them with the results of quantitative cultures of specimens obtained by protected brush catheters (PBC) inserted into involved areas of lung parenchyma. Twenty-two patients on mechanical ventilation for at least 72 hours, with new radiographic infiltrates and fever, were studied. Tracheal aspiration was performed in the usual manner using sterile disposable kits. Immediately thereafter, patients underwent fiberoptic bronchoscopy, and PBC specimens were obtained from the areas of new radiographic infiltrates. Tracheal aspirates were gram stained and cultured aerobically, and antibody coating of bacteria was determined by fluorescence microscopy. Quantitative culture of PBC specimens contained ≥ 103colony forming units per brush in 16 of the 22 patients; a smaller number of organisms was present in two additional patients. In TA from all 22 patients, gram stains revealed polymorphonuclear neutrophils and bacteria. Cultures of TA revealed potential pathogens in 20 patients, and in 15, multiple pathogens were present. The bacteria isolated from PBC also were present in 14 of the 16 patients with ≥ 103CFU in PBC cultures (88%). Antibody coating was present in TA from 12 patients, and antibody coating correlated poorly with cultures of PBC specimens. The authors conclude that while gram stains and cultures of TA are often nonspecific, organisms cultured from lung parenchyma using PBC usually also are present in TA. The presence of antibody-coating does not improve the specificity of gram stain results.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID

摘要:

A 32-year-old woman with Hutchinson-Gilford disease (progeria) is described. The absence of complete sexual maturation has been considered characteristic of the syndrome, but this woman delivered a normal child at the age of 23.

ISSN:0002-9629    

出版商:OVID    

年代:1989

数据来源: OVID