Cyclodextrin nephrosis in the rat.

The renal toxicity of the Schardinger dextrins, alpha and beta-cyclodextrin, is manifested as a series of alterations in the vacuolar organelles of the proximal convoluted tubule. These changes begin as an increase of apical vacuoles and the appearance of giant lysosomes. The giant lysosomes characteristic of cyclodextrin nephrosis are notable because of the prominent acicular microcrystals embedded in the lysosomal matrix. Giant vacuoles devoid of acid phosphatase reaction product are found in advanced lesions. The vacuolar apparatus shows advanced changes prior to manifestation of lesions in mitochondria and other organelles. These observations indicate a role of the vacuologenic apparatus in the nephrotic process. Intracellular concentration of toxin via the lysosomal pathway represents a perversion of the physiologic function of the proximal tubule which ultimately leads to cell death.     

Expanding cerebellar lacunes due to dilatation of the perivascular space associated with Binswanger's subcortical arteriosclerotic encephalopathy

An 80-year-old hypertensive woman developed right hemiplegia and died 24 hours after admission. Neuropathologic examination revealed multiple cerebral infarcts of various ages and diffuse subcortical arteriosclerotic encephalopathy. Clusters of asymptomatic "expanding" lacunes, due to dilatation of the perivascular spaces, were found in both dentate nuclei. These cavities, which presented as space-occupying lesions, were surrounded by a single layer of flattened cells and contained 1 or more sections of normal-looking arterioles. Such a topographic grouping of lacunes in the dentate nucleus has not been described previously. The mechanism of widening of the perivascular compartment remains unclear; its occurrence in a hypertensive patient and its association with typical Binswanger's subcortical arteriosclerotic encephalopathy and severe atherosclerosis with multiple infarcts suggest a common pathophysiologic mechanism possibly including an alteration of the blood-brain barrier.     

Alterations in dopamine and 5-hydroxytryptamine (5-HT) function during barbiturate dependence and withdrawal in mice

Mice were rendered barbiturate-dependent by chronic feeding with barbital-con taining food. Brain dopamine turnover was significantly increased in barbital withdrawal, whereas 5-hydroxytryptamine (5-HT) turnover was significantly decreased. Severity of with drawal was assessed by measuring the convulsions following a dose of 33 mg/kg mer captopropionate (MPA). The neurotoxins 6-hydroxydopamine and 5,6-dihydroxytryptamine as well as metergoline (5 mg/kg) increased the severity of MPA convulsions. Quipazine (20 mg/ kg) attenuated the convulsions. The results are consistent with the hypothesis that diminished 5-HT function may contribute to the barbital withdrawal syndrome. Behavioural responses to serotonergic drugs were enhanced in barbital-dependent mice compared to controls, but [(3)H]- 5-HT binding to crude membrane fractions was similar in both groups with a single high affinity site.     

Accessory septum transversum. The first case report

Duplication of the septum transversum occurred in a newborn with respiratory distress thought clinically to be due to diaphragmatic paralysis. Surgical plication of the "floppy" diaphragm was attempted via a transabdominal approach. The anomalous septum transversum was perceived to be the diaphragm and was plicated. The central tendon of the diaphragm was redundant and surgical plication may have improved respiratory function. In this first case report, embryology of the diaphragm is reviewed and correlated with autopsy findings. A surgical approach to possible correction is proposed.     

The effect of hyperglycemia on isolated rodent islets transplanted to the kidney capsule site

The effect of hyperglycemia on transplanted rat pancreatic islets was studied using a new technique for transplanting a defined number of islets in a blood clot. Normal or streptozotocin-diabetic DA rats were given 400 DA islets under the left kidney capsule (a number shown to be insufficient to reverse diabetes). After 2 weeks the diabetic rats were given a further 1000 islets under the right kidney capsule to reverse diabetes. Kidneys from both groups were examined at 2 weeks after the initial islet implant and at 3 months for both gross and histological appearance and for insulin content. After 2 weeks left kidneys from nondiabetic rats showed abundant islet tissue, with an insulin content of 116 (+/- 14 SEM) milliunits, compared to 1 +/- 0.5 milliunits in the right kidney. Kidneys from diabetic rats showed no islets recognizable grossly. Histological examination showed vacuolated tissue scarcely recognizable as islet tissue, and the insulin content of the left kidney was reduced to 18 +/- 5 milliunits. However, 3 months after reversal of diabetes by transplantation of 1000 islets to the right kidney, histologically "normal" islet tissue was again visible on the left kidney, and the insulin content was 160 +/- 36 milliunits. Islets left in normal animals for 3 months contained 195 +/- 50 milliunits. These experiments show that islets implanted beneath the kidney capsule in diabetic rats are not destroyed by two weeks hyperglycemia. This suggests that protection of islets after implantation by insulin treatment is unnecessary, even in the presence of a persistently raised blood sugar.     

Quality control in diagnostic radiology at Mayo Clinic

During the past five years in the department of diagnostic radiology at Mayo Clinic, a quantitative quality control program has been developed and expanded. Its goal is to assure consistent image quality while minimizing exposure to radiation and reducing costs wherever possible. The key to the program is the collection of quantitative data, ie, each parameter is evaluated by an objective, not a subjective, measure which is accurate and repeatable even if the measurement is made by various persons. Operating levels and control limits have been established for all measurements, with the control limits set so changes are quantitatively noted before changes occur in the images presented to the diagnostic radiologists.     

Capital financing techniques for health care facilities: an historical overview

Realizing that a thorough discussion of capital financing techniques for health care facilities would fill several volumes, this article presents an overview of the techniques currently used in the industry. Included is an outline of the basic features, applications, and costs of the various techniques. Because financing techniques in current use evolved from earlier forms, the chronological format adds a measure of clarity and logic to the development of health care financing. The primary focus will be on private, voluntary hospitals since they comprise the majority of the health care financing volume. A particular technique's applicability to public facilities, nursing homes, retirement centers, for-profit facilities, and freestanding facilities is noted, however, when appropriate.