Biomedical subjects
Publications and source records attributed to J J Houben.
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We report five cases in which anorectal stenosis was associated with chronic administration of suppositories containing paracetamol and acetylsalicylic acid. All patients were females taking suppositories for chronic migraine. Patients experienced anal pain, tenesmus, fecal incontinence, and, in two cases, intestinal obstruction. Lesions were characterized by a severe circular narrowing of the distal rectum with superficial ulcerations. Radiographs demonstrated the presence of sinus-tract-like formations in the diseased segment and thickening of the rectal wall. Histologic examination showed signs of chronic inflammation with deep ulcerations associated with obliteration of the lamina propria by a fibromuscular proliferation, as was described in the solitary ulcer syndrome of the rectum. Rectal administration of suppositories was discontinued in all the patients. Two patients were improved by anorectal dilatation, but the remaining three required a left proctocolectomy with subsequent coloanal anastomosis. The use of such suppositories must be restricted.
Non-parasitic solitary liver cysts are rare in children. Yet they should be included in the differential diagnosis of superior abdominal masses. We report one case in a 7-year-old boy that illustrates the difficulties of the diagnosis.
The pharmacokinetics of epidural clonidine 150 micrograms was studied in 13 patients who had undergone abdominal hysterectomy. Plasma clonidine concentrations were measured up to 19 h in eight patients. In another five patients frequent blood sampling was performed only during the first 20 min to define early vascular uptake better. Peak plasma clonidine concentrations of 1.08 +/- 0.35 ng ml-1 (mean +/- s.d.) were reached between 5 and 10 min after injection. Plasma elimination half-life was 829 +/- 157 min and plasma clearance was 177 +/- 28 ml min-1. There was a significant decrease in arterial blood pressure within 10 min of the injection of clonidine. The maximum decrease in systolic blood pressure, from a pre-injection value of 135 +/- 24.7 to 99 +/- 14.4 mmHg (18.0 +/- 3.3 to 13.2 +/- 1.9 kPa), occurred at 60 min. Blood pressure remained significantly lower than the pre-injection value for 4 h. There was no change in heart rate. Verbal analogue pain scores, on a scale 0-10, decreased from a median of 7.6 before clonidine to 5.0 after 30 min (P less than 0.05). The median score at 60 min was 4.3. Thereafter, pain scores were not significantly different from the control score. We conclude that epidural clonidine 150 micrograms produces only moderate and short-lived postoperative analgesia. Absorption of clonidine from the epidural space into the blood is very rapid and may contribute to the hypotension that occurs.
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In the rat, the development of the limb bud can be impaired by amniotic puncture. Selective haemorrhages are observed within 1 hour of the treatment. An ultrastructural analysis was undertaken to uncover the cytological changes associated with these haemorrhages. The earliest effect of oligohydramnios is the appearance of a periendothelial oedema which separates the mesodermal cellular processes from the endothelial basal lamina. The loosening of the latter and the distortion of the endothelial cells occur almost simultaneously. Subsequent damage of the mesodermal cells ensues, the ectoderm and the preskeletal condensations remaining unaffected. Only general damage of the embryo affecting all tissues will lead to the complete necrosis of the limb bud and even to foetal death. The great variability of skeletal defects observed in amniocentesis syndrome can be accounted for by the higher resistance of the differentiating cells to a decrease in blood supply.
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Diaminobenzidine (DAB) histochemistry was used to determine enzymatic or non enzymatic peroxidase activity in the rat limb bud on days 12 and 13 of gestation. The optimal technical conditions were determined. Light microscopy revealed the presence of positive intracellular granules in the apical ectodermal ridge (A.E.R.) and in the condensed mesoderm. Their distribution in the A.E.R. shows a caudo-cephalic gradient. Electron microscopy, red oil red, and supravital Nile blue staining suggest the lipidic nature of these granules. The hypothesis of an endogenous pseudo- or peroxidase activity are discussed.
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Experimental oligohydramnios has been induced in pregnant rats on the 15th gestational day. Characteristic features of the amniocentesis syndrome can be observed in the posterior limbs and tail early after the amniotic puncture. Histological studies of the affected limb buds reveal immediate endothelial rupture of the marginal vein in the interdigital areas. General and nonspecific effects of the syndrome appear after 30 minutes: venous congestion, blebs, and periendothelial oedema. Such vascular disturbances can be either reversible or lethal. Proper regulation of the haemorrhagic effects does not occur. Growth and differentiation of the condensed digital rays are often unimpaired. Since the condensed preskeletal rudiments are spared by the haemorrhage, resorption of the hematoma results in limb defects which may be limited to the soft tissues. The haemorrhagic sites are selectively dependent on the vascular pattern of the developing limb at the time of experiment. Current hypotheses formulated to explain the amniocentesis syndrome are reviewed on the basis of the new descriptive data. Congenital constriction band syndrome and amniotic ruptures have been observed in rare cases.
Oral contraceptive steroids increased the residence time of caffeine in 9 young women by a factor of 2. The effect was already manifested during the first cycle 2 weeks after starting oral contraceptive steroids (OCS) and was slightly increased in the second cycle, after 6 weeks on OCS. Toxic effects attributed to oral contraceptive steroids may in part be indirect and due to prolonged retention of absorbed toxic agents to which women are exposed.
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In a series of 388 kidney transplantations performed in 328 patients, aseptic bone necrosis was diagnosed in 27 patients. Forty seven lesions were detected. The femoral head was most often involved (33 cases) followed by the femoral condyle (10 cases), the head of the humerus (3 cases) and the carpal navicular bone (1 case). Sixteen patients had multiple lesions. The first symptoms occurred between the fifth month and the sixth year post-transplantation. With our immunosuppressive protocol, the probability of developing aseptic bone necrosis is 5.2% at one year, 11.3% at two years and 16.3% at six years. The incidence of steroid diabetes is higher in patients with aseptic bone necrosis (26%) than in patients without bone lesions (11%). Conservative treatment was successful in 60% of the cases.
The effects of the topical application of beclomethasone dipropionate (a corticosteroid) on the aryl hydrocarbon hydroxylase (AHH) activity in epithelial tissue (lung and skin) were studied. To evaluate the results of the pre-treatment with beclomethasone dipropionate a comparison was made with the effects of the topical application of benzanthracene (a polycyclic aromatic hydrocarbon and a known inducer of AHH activity). AHH activities were increased 2.5 to 5-fold in lung and about 20-fold in skin of mice after topical application of benzanthracene. However, after pre-treatment with beclomethasone dipropionate no induction of AHH activity could be observed, either in lung or in skin. The implications of these findings are discussed.