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Biomedical subjects

J Petit

Publications and source records attributed to J Petit.

At least 181 records · Page 10Linked to original sources
PubMed1990

Hypoplastic transverse arch and coarctation in neonates. Surgical reconstruction of the aortic arch: a study of sixty-six patients.

From Jan. 1, 1983, to Jan. 1, 1988, 66 consecutive neonates with coarctation and severe hypoplasia of the transverse arch underwent coarctation repair by resection of the coarctation and reconstruction of the aortic arch. Mean age at operation was 14 +/- 8 days, ranging from 2 to 30 days; 63% of the newborn infants were less than 2 weeks of age. The coarctation was isolated in 23%, associated with a ventricular septal defect in 39%, and associated with complex anomalies in 38%, including 16 cases of transposition of the great arteries or doublet-outlet right ventricle plus ventricular septal defect, two cases of simple transposition, two of corrected transposition plus ventricular septal defect, and five cases of "hypoplastic" left ventricle. The surgical technique comprises a wide resection of the coarctation extended to the contiguous ductal tissue followed by the reconstruction of the aortic arch in bringing the descending aorta into the concavity of the aortic arch. This technique is able to relieve the obstruction of the aortic arch provided that (1) the descending aorta is widely dissected to allow mobilization and (2) the incision of the transverse arch is extended proximal to the ostium of the left carotid artery. The operation was performed through a left thoracotomy in 62 patients and through a sternotomy in four additional neonates with transposition and ventricular septal defect who underwent a one-stage repair with aortic reconstruction, closure of the defect, and arterial switch. The overall early mortality rate (less than 30 days) was 14% (9/66; 95% confidence limits = 5% to 22%), including four deaths occurring within the first month, at a concomitant or subsequent repair of the associated anomaly. There were six late deaths, all related to the associated lesions. The overall mortality rate was 23% (15/66; 95% confidence limits = 13% to 33%). The mean follow-up was 21 +/- 10 months, ranging from 6 to 66 months. Actuarial survival rates at 5 years are 72% +/- 10% for the overall group; 87% +/- 17% for simple coarctation; 88% +/- 12% for coarctation and ventricular septal defect; and 52% +/- 18% for complex coarctation. The rate of recurrent coarctation was 12.5% (95% confidence limits = 2% to 23%), leading to five reoperations with no deaths. Freedom from reoperation was 89.5% +/- 9% at 5 years. This technique of coarctation repair offers several advantages: low operative mortality, complete relief of the left ventricular obstruction, wide resection of the ductus tissue, absence of prosthetic material, and preservation of the left subclavian artery.

Aorta, Thoracic↗
PubMed1990

[Renal parenchymal malakoplakia. A case report].

A case of renal parenchymal malakoplakia, with tumoral appearance is reported here. The clinical, pathological, and imaging (including US, CT and arteriography) findings of this unusual site of the disease, whose diagnosis requires necessarily a biopsy, are presented.

Angiography↗
PubMed1989

Does stimulation of sympathetic axons elicit an increase in cat spindle afferent discharge detectable by the antidromic collision technique?

Averaged antidromic action potentials of Group I and Group II fibres elicited in cats by stimulation of L7 and S1 dorsal roots were recorded from intact tibial nerves (near the ankle) either in absence of or during repetitive stimulation of the ipsilateral lumbar sympathetic chain. This was done to test the suggestion that stimulation of noradrenergic sympathetic axons may elicit, in spindles of foot muscles, a substantial increase in the firing rate of secondary endings, capable of reducing the size of afferent antidromic volleys by collision with orthodromic impulses. We found that potentials recorded during sympathetic stimulation were identical to those recorded in absence of stimulation. The reduction in size of a component of the compound action potentials led from the intact tibial nerve during stimulation at 10-20 Hz of the sciatic nerve with C strength pulses, as described by Grassi, Filippi and Passatore (Brain Research, 435 (1987) 15-23), was observed in certain conditions of stimulation. However this reduction cannot be ascribed to antidromic collision, because it is still observed after severing the tibial nerve distal to the recording electrode.

Action Potentials↗
PubMed1989

Activation of Golgi tendon organs by asynchronous contractions of motor units in cat leg muscles.

Discharges from individual tendon organs of peroneus tertius muscle activated by the isometric contractions of single motor units were recorded in anaesthetized cats. Pairs of motor units acting on the same tendon organ were stimulated asynchronously at frequencies eliciting unfused contractions. Tendon organ responses to such contractions did not display a linear relation between discharge frequency and contractile force recorded at the muscle tendon. In several instances, one of the motor units exerted a predominant influence on the response of the tendon organ, even though this unit did not produce the strongest activation of the receptor when stimulated on its own.

Action Potentials↗
PubMed1989

Chronic nonspherocytic hemolytic anemia (CNSHA) and glucose 6 phosphate dehydrogenase (G6PD) deficiency in a patient with familial amyloidotic polyneuropathy (FAP). Molecular study of a new variant (G6PD Clinic) with markedly acidic pH optimum.

A new glucose-6-phosphate dehydrogenase (G6PD) variant with severe erythrocytic G6PD deficiency and a unique pH optimum is described in a young patient with chronic nonspherocytic hemolytic anemia (CNSHA) and familial amyloidotic polyneuropathy (FAP). Chronic hemolysis was present in the absence of infections, oxidant drugs or ingestion of faba beans. Residual enzyme activity was about 2.6% and 63% of normal activity in erythrocytes and leucocytes, respectively. A molecular study using standard methods showed G6PD in the patient to have normal electrophoretic mobility (at pH 7.0, 8.0 and 8.8), normal apparent affinity for substrates (Km, G6P and NADP) and a slightly abnormal utilization of substrate analogues (decreased deamino-NADP and increased 2-deoxyglucose-6-phosphate utilization). Heat stability was found to be markedly decreased (8% of residual activity after 20 min of incubation at 46 degrees C) and a particular characteristic of this enzyme was a biphasic pH curve with a greatly increased activity at low pH. Although molecular characteristics of this variant closely resemble those of G6PD Bangkok and G6PD Duarte, it can be distinguished from these and all other previously reported variants by virtue of its unusual pH curve. Therefore the present variant has been designated G6PD Clinic to distinguish it from other G6PD variants previously described.

Adult↗
PubMed1989

Pharmacokinetics of metapramine and its demethylated metabolites in plasma and brain of mice.

Previous studies on pharmacokinetic parameters of tricyclic antidepressants (TCAs) in rodents have shown different results from those obtained for the same drugs in man. The kinetics of metapramine (META) and its major demethylated metabolites (METs) were studied in the SWISS CD 1 mouse after acute administration in order to establish the pharmacokinetic parameters in plasma and brain. The plasma half-life (T1/2) was very short (87 min) compared with the half-life (7 h) in man. The metabolism of META was intensive as was the transfer of META and its metabolites into the brain. The kinetic profiles of the substances were quite similar both in plasma and in brain, namely a bicompartment open model. META was rapidly absorbed (Tmax = 10 min) into and quickly eliminated (T 1/2 = 40 min) from the brain. These parameters were used to schedule sampling (blood and brain) at the appropriate time after acute administration of increased doses. The administered doses were significantly correlated to firstly the plasma or brain levels of META, secondly the plasma levels of the main monodemethylated metabolite (MET I), and thirdly the plasma or brain levels of META + METs. Finally, the evolution of plasma and brain levels of the substances was studied after repeated injections (i.e. every 40 min) and confirmed the high affinity of META and its metabolites for the brain regions.

Animals↗
PubMed1989

Unloading of tendon organ discharges by in-series motor units in cat peroneal muscles.

1. The discharges from individual Golgi tendon organs of peroneus tertius and brevis muscles were recorded in anaesthetized cats during the isometric contractions of single motor units. Upon combined contractions of several motor units, two sorts of unloading effects were observed. 2. First, the contraction of a motor unit which, by itself, was without action on a tendon organ could produce a reduction in the response of the receptor to one of its activating motor units. Unloading effects exerted by such in-parallel motor units could effectively interfere with the actions of in-series motor units on the receptor. 3. Second, the contraction of a motor unit activating a tendon organ could reduce the response of this tendon organ to the contraction of another of its activating units. This new type of unloading effect, exerted by in-series motor units, was demonstrated by the fact that the simultaneous contraction of both units elicited less discharge from the receptor than the contraction of a single unit. 4. Unfused contractions of a fast-type motor unit eliciting a response in which the tendon organ discharge was driven 1:1 at the frequency of stimulation of the motor unit, could exert unloading actions on the response of the receptor to another motor unit eliciting a higher discharge frequency. 5. In-series unloading actions were exerted not only by fast-type motor units developing large forces, but also by relatively small slow-type motor units. 6. The high incidence of in-parallel and in-series unloading effects suggests that their consequences may be functionally significant. When large numbers of motor units are being recruited in a muscle, unloading effects might result in a limitation of the Ib afferent discharges from this muscle, preventing an excessive increase of autogenetic inhibition.

Action Potentials↗
PubMed1989

Metastatic cancer spread at the laparoscopic puncture site. Report of a case in a patient with carcinoma of the ovary. Case report.

The aim of this study is to draw attention to the possibility of the occurrence of a metastatic spread at the laparoscopic entrance site in patients suffering from a carcinoma of the ovary. This event has rarely been mentioned in medical literature before. A case is presented here in which a localized tumoral lesion appeared after a laparoscopic staging study in the abdominal wall, exactly at the site used for the introduction of the accessory laparoscopic trocar in a patient suffering from a carcinoma of the ovary.

Abdominal Muscles↗
PubMed1989

[Hypothenar aneurysm of the ulnar artery. Apropos of a case treated by excision and anastomosis].

A case of aneurysm of the ulnar artery, located in the region of the hypothenar eminence is reported. This true traumatic aneurysm had a reconstructive treatment, considering the arterial anatomy of the patient's hand. A resection followed by an end to end anastomosis has been done with a good post-operative result at two years and a half. The unusualness of this pathology, the predominance of its traumatic and occupational etiology are emphasized. True and false traumatic aneurysms are described. The diagnosis of aneurysm is primarily clinical. Arteriography is interesting in the preoperative check-up. Reconstructive surgery is now preferred.

Anastomosis, Surgical↗
PubMed1989

[Cancer of the anus arising within condylomata acuminata. Apropos of 2 cases. Review of the literature].

Two cases of squamous carcinoma of the anus developing from condylomata acuminata are reported. The general characteristics of condylomata acuminata are reviewed: viral etiology due to HPV virus, histological appearance and role in the the genesis of certain cancers. The association of condylomata acuminata and cancer of the anus is more particularly studied in a review of the literature: etiology, anatomoclinical aspects, treatment and current state of knowledge concerning the oncogenic role of HPV virus at this site.

Adult↗
PubMed1989

[Müllerian cyst. Apropos of a case of the prostatic region].

One case of the unusual entity, prostatic müllerian duct cyst, is reported. Depending on their volume, they may, like in our case-report, or may not be symptomatic. Ultrasonography, C.T. scan and vasoseminal vesiculogram precised its midline location and its relationships with other adjacent anatomic structures. The endo-uretral approach to drainage was used successfully.

Aged↗
PubMed1989

[Leptospirosis caused by Leptospira icterohaemorrhagiae of the pseudo-surgical type: a case].

The authors report a case of fatal leptospirosis due to Leptospira icterohaemorrhagiae revealed by typical signs of acute cholecystitis and associated with pancreatitis in a 73 year old patient presenting with gallstones. The initial clinical findings were highly suggestive of severe but typical cholecystitis and the final diagnosis was only considered when the patient's condition worsened despite surgery, with increasing obstructive jaundice and multiple organ failure. Pancreatitis was an autopsy finding. Misleading, especially gastrointestinal symptoms are frequent in leptospirosis. Hence an early diagnosis is an essential condition for a successful antibiotic management in severe cases of leptospirosis. This possibility should be considered whenever a patient presents with infectious obstructive jaundice. The patient has to be questioned concerning possible contact with contaminated animals and, when in doubt, the presence of specific antibodies should be investigated.

Acute Disease↗
PubMed1989

[Vindesine, CCNU, high-dosage ara-C, and prednisolone (VINAP regimen) in the treatment of relapsing or refractory non-Hodgkin's lymphomas].

Results of second line chemotherapy schedules to treat refractory lymphoma have usually been poor. In this study we have treated 21 patients with advanced non-Hodgkin's lymphoma, usually heavily pretreated, with VINAP regimen. This original four drug chemotherapy combination included: Vindesine, 2 mg/m2 iv on days 1 and 2; CCNU, 40 mg/m2 oral on days 3 and 4; Cytosine arabinoside, 2.4 g/m2 iv on day 3 to 6 and methyl-Prednisolone, 80 mg/m2 on days 1 to 6. Sixteen patients (76%) showed response, including 5 (23%) who achieved a complete remission (CR). Eight patients achieved a partial remission (PR), and two patients obtained an objective response. Although the responses to VINAP regimen were dramatic and rapid in onset, usually they were of short duration except in cases of lymphosarcoma cell leukaemia. The median duration of response for patients with CR was 42 weeks and for PR 11 weeks. Toxicity was acceptable, including predictable myelosuppression, frequent mucositis and occasional polyneuritis. Neither central nervous problems nor conjunctivitis or dermatitis had been seen.

Adolescent↗
PubMed1988

[Cardiac involvement in Behçet's disease. 12 cases].

Fifteen cardiac manifestations observed in 12 of a series of 196 patients with Behçet's disease are reported. In this retrospective study conducted in an internal medicine department, 5 cases of pericarditis and 4 cases of myocardial infarction were encountered. The other cardiac manifestations were observed only once. They included ventricular aneurysm, endomyocardial fibrosis of the right heart, aortic insufficiency, mitral valve insufficiency, mitral valve prolapse, and right heart failure consecutive to pulmonary arterial hypertension. There was no relationship between the severity of cardiac lesions and that of the extracardiac manifestations of the disease. Comparison of these data with those found in the literature showed that pericarditis is the most frequent pathology, but it usually regresses rapidly. Lesions of the coronary arteries, with or without myocardial infarction, consist of stenosis, occlusion or pseudoaneurysm requiring surgical treatment. Myocardial lesions (with the possibility of pseudoaneurysm) and endomyocardial right heart fibrosis are exceptional but fairly characteristic of Behçet's disease which they should suggest. Hughes-Stovin's syndrome may be complicated by pulmonary arterial hypertension, although death is generally caused by massive haemoptysis.

Adult↗