Multiple gastrointestinal atresias in three consecutive siblings: observations on pathogenesis

Three consecutive siblings with innumerable membranous gastrointestinal atresias, beginning at the prepyloric region and ending in the rectum, are reported. Microscopic examination of the small and large intestine showed multiple, tiny lumina each surrounded by a separate mucosa and muscularis mucosae but by a single muscular layer at the periphery. The pathological findings and hereditary character of these atresias suggest that a defect in recanalization during a solid stage of development involving the whole of the gastrointestinal tract may be the cause of these atresias.

Golgi/granule processing of peptide hormone and neuropeptide precursors: a minireview

Proteolytic processing of precursor proteins is a phylogenetically ancient and widely used mechanism for producing biologically active peptides. Proteolytic cleavage of proproteins begins only after transport to the Golgi apparatus has been completed and in most systems may continue for many hours within newly formed secretory vesicles as these are stored in the cytosol or transported along axons to more peripheral sites of release. Paired basic residues are required for efficient proteolysis in most precursors, suggesting that a small number of specialized tryptic proteases exist that have great site selectivity but can process many sites within the same precursor or in different precursors within the same cell, or in different cells or tissues. Cleavage-site choice may be strongly influenced by other factors, such as secondary and tertiary structure, but definitive structural information on precursor proteins is lacking. Modifications such as glycosylation, phosphorylation, and sulfation also are Golgi associated but are not known to influence proteolytic processing patterns. Golgi/granule processing also rarely occurs at sites other than pairs of basic amino acids, including single basic residues ( trypsinlike ), Leu-Ala, Leu-Ser, or Tyr-Ala bonds ( chymotrysinlike ) as well as other specialized nontryptic cleavages, suggesting that mixtures of proteases coexist in the Golgi/granule system. Cathepsin B-like thiol proteases, or their precursors, have been implicated as the major processing endopeptidases in several systems. Carboxypeptidase B-like enzymes also have been identified in secretion granules in several tissues and appear to be metalloenzymes similar in mechanism to the pancreatic carboxypeptidases, but with a lower pH optimum. The role of the Golgi apparatus in sorting newly formed secreted products from lysosomal hydrolases may have permitted the development in evolution of an intimate relationship between certain of the lysosomal degradative enzymes, such as cathepsin B or its precursors, and the Golgi/granule processing systems. The sequestration of the proteolytic products of precursors within secretion granules leads to the coordinate discharge of highly complex mixtures of peptides having related or overlapping biological activities. The cosecretion of nonfunctional peptide " leftovers ," such as the proinsulin C-peptide, can serve as useful markers of secretion or cellular localization, as well as of evolutionary relation ships. Errors in cleavage due to point mutations in precursors have been identified in several systems, leading to the accumulation of incorrectly processed materials in the circulation. These and/or defects (ABSTRACT TRUNCATED AT 400 WORDS)

Identification of a 31,500 molecular weight islet cell protease as cathepsin B

A method for the preparation of a radioisotopically labeled active-site directed reagent for proteases (125I-Tyr-Ala-Lys-ArgCH2Cl) is described, and an example of its use as a sensitive method for identifying trypsin-like proteases is provided. This high specific activity reagent was then used in an attempt to identify proteases in rat islets of Langerhans involved in the conversion of proinsulin to insulin. Previous studies have indicated that the endoprotease involved in proinsulin conversion is a cysteine proteinase and that 125I-Tyr-Ala-Lys-ArgCH2Cl affinity labels an islet crude granule fraction protein having a molecular weight of 31,500. Here we demonstrate, using a probe of higher specific activity, that the major affinity-labeled proteins of the islet crude granule fraction, when displayed by sodium dodecyl sulfate gel electrophoresis, have molecular weights of approximately 39,000 (5%), 31,500 (53%), and 5,000-6,000 (37%), with several other minor proteins (less than 5%) also labeled. The two predominant labeled proteins were mainly soluble rather than membrane bound, and they exhibited patterns of competition with various inhibitors that were similar to the pattern shown by the conversion of proinsulin to insulin in vitro. A rabbit antibody to rat liver cathepsin B immunoprecipitated both affinity-labeled 31,500 and 5,000-6,000 molecular weight proteins, and on the basis of this and structural considerations the 31,500 molecular weight cysteine protease is identified as cathepsin B. The 5,000-6,000 molecular weight peptide is an NH2-terminal, active site cysteine-containing, proteolytic fragment of the 31,500 molecular weight protein. Because cathepsin B is not per se a candidate for the proinsulin convertase because of its excessively broad substrate specificity, these studies suggest that a similar enzyme or a modified form of this enzyme is active within the secretory progranules, whereas the more typical cathepsin B may be largely confined to lysosomal contaminants in our granule preparations.

Cortical bone senescence and mineral bone density of the humerus

Study of the humeral cortex of 89 acute cadavers showed that an important factor contributing to the physiologic bone loss of aging is increasing bone porosity. Mean cortical porosity increases in both sexes with age, from 4.6% in men and 4% in women at 40 years of age to 10% and more at age 80. In the population studied, no significant difference of porosity was observed between men and women. Apparent mineral density is linked to porosity, and decreases markedly with age in women. Changes in men are lesser in magnitude and show a larger difference of density values. Correction of the apparent mineral density, by a factor reflecting the proportion of vascular and resorption spaces in the cortical bone, produces a true mineral density which does not vary significantly with age in either sex. The density values obtained for the proximal humerus differ from those in the literature which represent the femur. However, they are more readily compared with the results of clinical densitometry and may have greater clinical applications.

Tennis elbow: incidence in local league players

Seventy-four local league players were surveyed through a questionnaire and interview to establish the incidence of tennis elbow, the perceived causes, preventive measures taken and their perceived effectiveness. Of these 35% suffered from tennis elbow, 77% of those critically. The tennis racquet used, technique and timing and the condition of the court were perceived as the main causes, whilst playing tennis frequently was seen as the main contributory factor. The effectiveness of both medical treatment and non-medical measures are noted, but only 5 cases of complete recovery from the injury are reported. Medical help was not sought in almost 50% of the cases, and lack of faith in the GP's interest or advice was noted. Information about tennis elbow did not appear to be easily accessible. More sports injury clinics and wider dissemination of information are suggested. The American research is reviewed.

Sleep disturbances in a series of elderly patients: polysomnographic findings

A group of 27 elderly patients with complaints of either chronic insomnia or excessive daytime sleepiness were studied in the Sleep Evaluation Center of Western Psychiatric Institute and Clinic during the period January 1977-June 1979. On the basis of anamnestic data from patients and bedroom partners, together with polysomnographic findings, sleep disturbances were classified according to the nosology of the Association of Sleep Disorders Centers. Of the 27 patients, 19 had disorders of initiating or maintaining sleep (DIMS), 7 had disorders of excessive somnolence (DOES), and 1 had parasomnia (episodic nocturnal wandering). Of the 19 DIMS patients, two-thirds had either a primary affective disorder (depression) or a persistent psychophysiologic disturbance. Of the 7 DOES patients, 6 had a primary sleep disorder such as a sleep apnea syndrome or narcolepsy-cataplexy. Additional electroencephalographic sleep data are presented on elderly patients with primary nonpsychotic depression. The latency of rapid eye movements (REM) in the depressed patients was shorter (p less than 0.05) than in patients with a persistent psychophysiologic disturbance. The percentage of REM sleep was significantly elevated (p less than 0.05) in the depressed group, and intermittent wakefulness was decreased (p less than 0.01). The causes of sleep disturbance in the elderly are both heterogeneous and complex. The need for accurate differential diagnosis and a multiaxial approach is stressed.

[Ultrasonography of the pancreas. Diagnostic problems and findings in cases of solid pancreatic masses (author's transl)]

By using rigourous examination techniques and interpretive criteria, ultrasonography of the pancreas can, in many cases, confirm the etiological diagnosis of solid pancreatic masses. Factors influencing diagnosis are the volume and shape of the pancreas, the ultrasound structure, the attenuation of ultrasounds, the outline of the pancreas, and the effect on neighbouring structures. The association of signs is often characteristic and can differentiate benign from malignant masses.

A comparison of depression and physical illness in men and women

A limited self-rating depression scale given to male and female factory workers indicated that subclinical depressive symptoms were correlated with visits to the factory health service for females and with absenteeism from work for males. In general, the females acknowledged more depression symptoms.

Promotion of monolayer formation in cultured whole pancreatic islets by 3-isobutyl-1-methylxanthine

Normal adult rat islets usually remained intact and encapsulated, even after many days in culture. In contrast, islets cultured in the presence of the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (0.1 mM) attached more readily to the surface of plastic culture dishes and almost uniformly formed monolayers of endocrine cells. The mechanism of this effect is not known but presumably involves increases in cellular cyclic AMP content. Fibroblast growth did not appear to be stimulated by the inhibitor. These adult pancreatic endocrine monolayer cultures can be produced readily and provide useful preparations for further morphological and biochemical studies of factors affecting the differentiation, growth, and regenerative capacity of islet cells.

Proceedings: Obstructive uropathy due to unusual pelvic swellings

Images

Oestrogen and the early stages of hexadimethrine necrosis of the anterior pituitary and adrenal cortex

Infarction of the anterior pituitary and adrenal cortex caused by hexadimethrine in experimental animals was found to be variable in incidence and extent. Pretreatment with oestrogen made the lesions more severe and almost of constant occurrence.

The early stages of the lesions were studied in rats from 1 to 6 hr. after the administration of hexadimethrine. The local vasospasm which caused the infarction in the adrenal cortex seemed to pass off in 2 or 3 hr. and to be followed by a failed reflow which produced much haemorrhage. On the other hand, it appears that there was little or no reflow into the dead anterior pituitary during the first 6 hr. Necrotic changes did not develop within that period in animals pretreated with oestrogen but secondary thrombosis occurred in vessels of the marginal zones of the necrotic anterior pituitary after about 12 to 24 hr.

Tetracycline fluorescence in experimental tumours

Images