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Biomedical subjects

J Petit

Publications and source records attributed to J Petit.

At least 217 records · Page 12Linked to original sources
PubMed1987

[Summation of maximal tetanic tensions developed by slow or fast motor units of the peroneus longus muscle in the cat].

The maximal tetanic tension developed by the simultaneous contraction of several slow motor units (measured tension) is always greater than the sum of the tensions developed by each unit individually (cumulated tension). Generally, the same holds true for fast units but, for measured tensions of same value, the difference between measured tensions and cumulated tensions is much smaller. It is sometimes negligible or even negative.

Animals↗
PubMed1987

[Comparison of the increase of stiffness produced during sinusoidal stretch of the long fibula muscle in the cat by the contraction of slow or fast motor units].

The increase in stiffness of cat peroneus longus muscle elicited by the contraction of homogeneous groups of motor units (slow, fast fatigue-resistant and fast fatigable) was measured during sinusoidal stretches (20-80 Hz) of small amplitude (40-100 micron). For comparable tetanic tensions, slow units increase muscle stiffness more than fast unit.

Animals↗
PubMed1987

[Maternal administration of indomethacin and neonatal tricuspid insufficiency].

The authors report the case of a neonate who presented since birth with refractory hypoxemia, peripheral edemas, ascites and pleural effusions. The mother had been given indomethacin for the 10 preceding days, in order to avoid premature labour. Echocardiography showed a tricuspid valve dysfunction with important regurgitation in the neonate. Under symptomatic treatment, clinical symptoms disappeared within 10 days. Echocardiography was normal by age 3 months. The responsibility of administration of indomethacin to the mother is discussed.

Female↗
PubMed1986

[Rheumatic mitral stenosis. The medical solution].

The first case of balloon catheter valvular dilatation for rheumatic mitral stenosis is reported in a 13 year-old child. The technique, under local anesthesia, required a transseptal access, then the introduction of one, then simultaneously 2 balloon catheters through the mitral valve. A perfect opening of the valve, without mitral insufficiency was obtained. This technique, even if difficult, seems to be adaptable to most children with rheumatic mitral stenosis.

Adolescent↗
PubMed1986

[Hemodynamic development of the auricular communication of the ostium secundum and sinus venosus type. Study of 1189 patients].

The haemodynamic data of 1,189 subjects with an atrial septal defect catheterised between 1953 and 1983 at the Marie Lannelongue Surgical Center and at Broussais Hospital was reviewed. Sixty per cent were under 20 years of age and 40 per cent were 21 to 75 years of age. The defect was an ostium secundum type in 89 per cent and sinus venosus in 11 per cent of patients. The commonest associated cardiac malformation was a partial anomalous pulmonary venous drainage which was present in 125 patients. Systolic and mean pulmonary arterial pressures decreased from a value slightly higher than normal between birth and 5 years of age to normal values between 5 and 20 years of age and then increased progressively to maximal values attained after 50 years of age (p less than 0.001). The proportion of patients with raised systolic and mean pulmonary arterial pressures increased with age after 20 years of age (p less than 0.001). A parallel increase in pulmonary blood flow was observed after 20 years of age, which was less marked than the increase in pressures, but nevertheless statistically significant (p less than 0.05). This increase in left to right shunt disappeared after 50 years of age. An increase in pulmonary resistances was observed after 20 years of age and persisted all through life (p less than 0.001). Two successive preoperative catheter studies were performed in 34 patients after a 6.4 +/- 4.7 years interval. In each patient, systolic pulmonary arterial pressures had increased and were significantly higher at the time of the second study (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1986

[Hemorrhagic Meckel's diverticulum. The place of abdominal scintigraphy with technetium 99m. Apropos of a case with gastric and pancreatic heterotopia].

A 12 year old child presented with a hemorrhagic Meckel's diverticulum, gastric heterotopia without identifiable ulceration and a totally aberrant pancreas. The diagnostic value of 99m-technetium abdominal scintigraphy in patients with Meckel's diverticula and gastric heterotopia, as well as the limits of this investigation, are discussed.

Child↗
PubMed1986

[Synovial cysts of unusual localization. 2 cases and review of the literature].

Two patients with true synovial cysts in atypical sites (internal compartment of knee and inguinal hollow) were investigated by radioarthrography, ultrasound and computed tomography imaging. The cyst in the hip region originated from a dilated serous bursa of the iliopsoas muscle that did not communicate or was no longer in communication with the joint. In contrast, the cyst of the knee appeared to be a lateral synovial capsule hernia. Positive diagnosis in both cases was dependent on combined ultrasound-CT scan imaging, this eliminating a tumor (sarcoma) of soft tissues. However, affirmation of the synovial origin (mesothelial covering of the wall) of the lesion was obtained by histology only, this allowing differentiation from a "capsular" (fibrous wall) cyst, which probably provokes similar ultrasound and CT scan images.

Aged↗
PubMed1986

Metastatic calcification in the thyroid gland demonstrated on bone scan in a patient with primary hyperparathyroidism.

Bone scanning agents are known to accumulate in extraskeletal sites. We report the case of a patient with primary hyperparathyroidism whose bone scan performed with [99mTc]HMDP revealed not only the classic pattern described in hyperparathyroidism, but also a striking visceral uptake in the lungs, heart, stomach, and thyroid gland. Metastatic calcification was found on histologic examination of the thyroid.

Aged↗
PubMed1986

[Emphysematous pyelonephritis. Review of the literature apropos of 4 new cases].

Based on four new cases of emphysematous pyelonephritis, the authors review a total or 59 interpretable cases of this rare disease reported in the literature. The general features of this condition are as follows: diabetic women are most frequently affected, the clinical context is generally very serious, the diagnosis is based on X-ray findings, radiating or crescent-shaped radiolucent gas images are observed with a non-functioning kidney on intravenous pyelography. CT scan was performed in two cases and confirmed the presence of air in the renal parenchyma and provided a better evaluation of the extension into the perirenal space. The only effective treatment is nephrectomy which has been able to improve the prognosis of this very serious disease, especially as the characteristic necrosis observed on histology leaves no hope of functional recovery.

Adult↗
PubMed1986

[Can diminished bladder compliance favor spontaneous bladder rupture?].

A case of spontaneous rupture of the bladder was observed in a 53-year-old woman. Physical evaluation and diagnostic investigations showed the following findings: initial urinary retention presumed to be psychogenic as the patient had a confusional state and was free of anatomic or neurologic complications; low bladder compliance observed upon urodynamic investigation on the 21st postoperative day and one year later; repeated coughing fits due to chronic bronchitis at the time of the accident. Rupture of the bladder requires the coexistence of an obstacle to urinary outflow and decreased parietal resistance to distension upon filling. According to the Laplace rule, the tension of the bladder wall (T) needed to resist distension is T = KPR, where P is the endovesical pressure and R the bladder sphere radius. Low bladder compliance therefore induces a disproportionate increase in intravesical pressure during filling and may be a significant etiologic parietal factor in the occurrence of spontaneous rupture of the bladder.

Compliance↗
PubMed1985

Simultaneous determination of metapramine and its demethylated metabolites in plasma by gas chromatography-mass spectrometry.

A capillary column gas chromatography--mass fragmentographic method for metapramine and its three major demethylated metabolites is described. Compounds are extracted from plasma using a double-extraction procedure and transformed into N-trifluoroacetyl derivatives. The detection is performed by monitoring specific ions for metapramine and for its metabolites with a mass detector. In spite of extensive metabolism in the liver and rapid elimination of metapramine, plasma concentrations of both metapramine and its metabolites can be simultaneously followed over 24 h after a single 150-mg oral dose, because of the sensitivity and selectivity of the method. This method has been successfully applied to the analysis of samples obtained from patients who were at steady state with metapramine and to a pharmacokinetic study in a healthy volunteer.

Biotransformation↗