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Biomedical subjects

R Michiels

Publications and source records attributed to R Michiels.

At least 109 records · Page 6Linked to original sources
PubMedDate not supplied

Enhancement by secretin of the apparently maximal hepatic transport of bilirubin in the rat.

The effect of secretin (0.4 C.U. per hr per 100 gm body weight) on bile flow and the apparent maximal hepatic transport of bilirubin (Tm) was investigated in the rat. When secretin was administered during an already established bilirubin-Tm condition, it increased bile flow and bilirubin-Tm by 15 to 20% over a 30- to 50-min period. Enhancement of bilirubin output correlated with augmented flow and was sustained by an increased rate of excretion of monoglucuronides. When secretin was given for 90 min before bilirubin loading, it enhanced biliary bilirubin concentration and output, largely as diglucuronides. Bilirubin-Tm correlated positively with glururonyltransferase activity in liver homogenates. In the isolated perfused rat liver, injection of secretin in the portal cannula failed to produce choleresis. Bilirubin uridine diphosphate-glucuronyltransferase activity was lower than in intact rats and higher after treatment than in controls. The effect of secretin had an early effect on hepatocytic bile flow and a later effect on conjugation. Maximal hepatic bilirubin output was modulated both by flow and conjugation rate; the two mechanism may act independently.

Animals↗
PubMedDate not supplied

An uncommon apudoma: a functional chemodectoma of the larynx. Report of a case and review of the literature.

The authors report a case of laryngeal chemodectoma in a 53-year-old man who died from general dissemination and lymphatic and subcutaneous metastases. This functional neoplasm secreted calcitonin revealed by fluorescence and biochemical tests and perhaps adrenaline-like substances. Its cells looked like the light chief cells of the human carotid body; they contained secretory granules and lysosomal formations. Thirty similar cases had been previously reported. The superior laryngeal glomi and more occasionally the inferior ones were the seat of these tumours which occurred with an equal frequency in both sexes. A hoarseness was often the unique symptom noticed during the several months or years preceding the first examination of this slow growing neoplasm. Nevertheless among the chemodectomas of the head and the neck region those arising in the larynx had the highest incidence of malignant evolution. Five of the patients presented a general dissemination, two had lymphatic metastases and one a local recurrence. The ultra-structural features and sometimes the rarely detected functional activity of these chemodectomas are those of apudomas whose cells might originate from the cephalic portion of the neural crests.

Age Factors↗
PubMedDate not supplied

Ciliated bodies in gynecologic cytopathology: parasite or cellular debris?

Ciliated bodies, similar to the ones described originally by Gaudefroy and Coliche, were discovered in fluid from an ovarian cyst and fluid in the Douglas pouch. These were reproduced experimentally by mucosal scraping of Fallopian tubes. In fact, they were of cellular origin from desquamation of the ciliated apical portion of columnar cells.

Adult↗
PubMedDate not supplied

[Neonatal hepatitis with alpha-1-antitrypsin deficit. Apropos of a personal case].

The authors report a case of neonatal hepatitis with alpha-1-antitrypsin occuring in a child of ZZ phenotype. The anatomopathological study carried out on two liver biopsies showed changes of common cholestatic hepatitis developing into cirrhosis, as well as intrahepatocytary globulins. Moreover, these globulins, P.A.S. positive after treatment by alphaamylase, fix an antialpha-1-antitrypsine antiserum. Ultrastructural analysis shows them to be masses of amorphous material, feebly osmiophilic, outlined by a unitary membrane the moniliform aspect of which recalls the ergastoplasmic membrane. These findings are identical to those already made in cases of cirrhogenous neonatal hepatitis by alpha-1-antitrypsine deficit reported in the literature. They point out the irreversibility of the affection which, after a stage of cholestatic hepatitis with or without inflammatory portal fibrosis, develops into cirrhosis. At this stage cholestasis has regressed or disappeared whereas portal sclerosis, often infiltrated with free elements, surrounds hepatic lobules and biliary neocanaliculi. But the globulins are still present and appear to be the specific feature of this deficit. By their ultrastructural and immuno-histochemical features, these globulins would represent a form of accumulation of alpha-1-antitrypsin in the hepatocytes which normally carry out the synthesis of this antienzyme. Accumulation in the hepatocytes proves excretory disturbance of hypothetical mechanism: structural anomaly, changes in the permeability of the membrane. Its role in the occurrence of hepatitis or cirrhosis lesions is still to be demonstrated but one may think that it consists in absence of inhibition of the enzymatic factors discharged during agressions.

Cholestasis↗
PubMedDate not supplied

Glucagon enhances bile flow, bilirubin uridine diphosphate-glucuronyltransferase activity and biliary bilirubin monoconjugate excretion in the rat.

Intravenous infusion of glucagon (100 micrograms/hr/100 g body weight) in rats produces a 20 to 35% increase in bile flow and enhances the activity of hepatic bilirubin uridine diphosphate-glucuronyltransferase to 132% after a 90 min infusion. When a bilirubin load is given to produce a constant and apparently maximal biliary bilirubin excretion rate (or transport maximum) the administration of glucagon increased the bilirubin transport maximum. The excretion rate of bilirubin monoglucuronides was more enhanced than that of diglucuronide. The enhanced rate of glucuronidation, assayed in vitro, correlated with the augmented biliary output and inversely with the plasma unconjugated bilirubin levels. It is concluded that glucagon, at the dosage used, leads to a higher formation rate of bilirubin monoconjugates and that the choleresis, also induced by the hormone, enhances the biliary secretion of the monoconjugates formed. The enhanced conjugation results in a decreased plasma concentration of unconjugated bile pigment and the associated choleresis leads to a decreased di- to monoconjugate ratio, opposite to what has been observed during bilirubinostasis and cholestasis. The secretory efficacy, as assessed from the bile-to-plasma concentration ratio, is enhanced for all bilirubin pigments after glucagon administration.

Animals↗
PubMedDate not supplied

[Anatomo-clinical features of Castleman tumour. Report of a case with a membrano-proliferative glomerulonephritis (author's transl)].

A case of retro-peritoneal lymphoid angio-follicular hyperplasia or Castleman's pseudo-tumour with normochromic hormocytic anemia and membrano-proliferative glomerulonephritis is reported in a 53 year-old man. Since the first description by Castleman in 1954, 259 other cases have been published. The anatomo-clinical study of our observation and of 198 cases collected in the literature bears out 3 types of clinical forms, according to the location of the pseudo-tumour: mediastinal, superficial and abdominal. The first ones generally asymptomatic are the most frequent whereas the last ones, less common, are often associated with biological abnormalities. In spite of these differences such neoformations present the same morphologic features. They are round or ovoid and well delimited by a capsule. Under this capsule a lymphoid vascular tissue surrounds follicules with central capillaries or arterioles. When plasma cells infiltrate the stroma, perturbations such as anemia or hypoalbunemia appear. Besides a nephrotic syndrome has been discovered in our observation and in that of Humpherys. In all the cases the removal of the pseudo-tumour induces the retrogression of the biological abnormalities and of the nephrotic syndrome. Neither a recidive nor another location of the disease are noticed later on. This evolution is probably the fact of a benign hyperplatic process which grows after an antigenic stimulation.

Abdomen↗