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Biomedical subjects

J Petit

Publications and source records attributed to J Petit.

At least 109 records · Page 6Linked to original sources
PubMed1995

[Respective indications of enteral or parenteral nutrition during pre- and post-operative periods].

Denutrition is often associated with poor postoperative outcome. However, a large body of evidence, from studies comparing perioperative parenteral (PN) or enteral (EN) nutrition to the absence of perioperative nutrition, suggests that perioperative nutritional support provides significant improvements in both nutritional status and postoperative clinical outcome in selected patients who are or will become malnourished. The aim of this study was to select and review all relevant articles comparing perioperative parenteral and enteral nutritional support, either in terms of clinical outcome, or risks and costs, or in pathophysiological terms. Twelve clinical reports were reviewed. All contained methodological flaws, mainly type II statistical error due to an insufficient number of patients, inaccurate primary diagnosis, absence of blinding, and lack of objective criteria of judgement. These concerns warrant caution in interpreting the results. Moderately strong (grade B) recommendations can only be drawn from these studies: PN (compared to early EN) is associated with a higher rate of sepsis in patients following abdominal trauma; EN is as efficient as PN in patients following surgery; EN is safe and cheaper than PN. PN formulae lack many important nutrients (glutamine, arginine, cysteine, peptides, fibers, n-3 polyunsaturated fatty acids, and nucleotides). Many experimental (animal) and some clinical (in non surgical patients) studies showed that PN (compared to EN) induces gut mucosal atrophy, liver dysfunction, gut bacterial translocation and immune dysfunction. The final aim of PN and EN would therefore strikingly differ. The qualitatively imperfect PN would only supply the fasting patient with quantitative amounts of calories and proteins. Due to initially limited digestive tolerance, EN provides less nutrition than PN does, but would finally lead to the same or even better outcome, due to its ability to counteract stress induced gut and immune dysfunction. Current evidence therefore suggests that early EN is superior to PN in trauma patients, and not different from but cheaper (and therefore more cost-effective) than PN in surgical patients. Further controlled, randomised, and blinded studies including sufficient sizes of groups are required, especially in the surgical setting, to address a large number of still unanswered questions.

Enteral Nutrition↗
PubMed1995

Failure of cefotaxime treatment in two children with meningitis caused by highly penicillin-resistant Streptococcus pneumoniae.

Two infants, aged 8.5 and 11 months, were admitted for meningitis caused by Streptococcus pneumoniae. Failure of cefotaxime led to the identification of highly penicillin-G-resistant strains. Minimum inhibitory concentrations (MICs) for penicillin were > 2 micrograms/ml, and cefotaxime MICs were 2 micrograms/ml. Both patients rapidly responded to a combination of i.v. imipenem and rifampicin. It is now mandatory to test in-vitro susceptibilities of Streptococcus pneumoniae to penicillin G and other beta-lactam agents when meningitis is diagnosed in infants.

Anti-Bacterial Agents↗
PubMed1995

Seeding of YACs over regions 1q41-q42.3 and 11q14.3-q23 with microdissection clones.

We describe the use of pooled, region-specific hybridisation probes to screen high-density replica filters of a human genome YAC library. The probes were derived by microdissection of an approximately 30-Mbp region subtending the translocation breakpoint on a der(1)(1;11)(q42.1;q14.3) chromosome. Of 70 microdissection clones used in pools of 4-10, 47 identified a total of 77 YAC recombinants, representing over 50% of the microdissected region. This strategy can easily be adapted to other poorly mapped subchromosomal regions of the human or other mammalian genomes and will provide a solid framework for detailed contig map constructions.

Chromosomes, Artificial, Yeast↗
PubMed1995

Influence of antibiotics and food intake on liver glutathione and cytochrome P-450 in septic rats.

Experimental sepsis in rats induces a restriction in spontaneous food intake and a drop in liver glutathione, cytochrome P-450 (P-450) and aminopyrine demethylase (AD) activity. The present study was designed to assess the effects of antibiotics alone or when combined with food deprivation on these variables. Eighty-nine male Sprague-Dawley rats were assigned to six groups: control (C), acute infection (experimental pyelonephritis, I), acute infection with antibiotics and food given ad lib. (IA), control with antibiotics (CA), acute infection with antibiotics pair-fed to I (IAR), and sham-operated pair-fed to I (SR). Liver glutathione, P-450 and AD activities were reduced by 45.2, 79.8 and 41.2% respectively in group I. Glutathione and AD significantly increased only in those infected rats given antibiotics and allowed free access to food. P-450 did not normalize within the study period in infected rats receiving antibiotics and food repletion. The risk of drug hepatotoxicity in acute septic states is therefore closely related to the nutritional status. From this point of view, nutritional support is almost as important as treatment of infection.

Aminopyrine N-Demethylase↗
PubMed1995

[Percutaneous closure of patent ductus arteriosus: results and costs compared to surgical closure].

The comparison of the clinical results and costs of the two methods of closure of patient ductus arteriosus was undertaken in two comparable groups of 40 patients treated in the same period in the same hospital. After transcatheter closure there was a 9% residual shunt rate at 3 years, the 2 patients with a residual continuous murmur being operated secondarily. The only complication was severe haemolysis which regressed after transcatheter ablation of the prosthesis. After surgical closure, there were no residual shunt. Some postoperative complications were observed in 20% of cases, usually benign (ventilatory problems, dysphonia or urinary infection), but occasionally more serious (peroperative lesion of the pulmonary artery). Morbidity, inherent to the technique of closure, was very different and much less in catheter closure. The average cost (daily cost x average length of hospital stay) was much less with transcatheter closure 38,558 francs versus 11,240 francs. On the other hand, the direct cost of transcatheter closure was greater than that of surgery: 32,798 francs versus 20,903 francs, the difference being related to the actual price of the prosthesis. The authors conclude that the 3 year results of transcatheter closure of patent ductus arterious make this technique a reasonable therapeutic alternative to surgery. From the safety point of view, the two techniques are comparable bu patient confort is greater with transcatheter closure for an increase in cost of the initial procedure which should decrease in relation to the types and prices of the prosthesis used.

Angioplasty, Balloon↗
PubMed1994

Static sensitivity of tendon organs to tetanic contraction of in-series motor units in feline peroneus tertius muscle.

1. The results of several studies have indicated an absence of any consistent relationship between the discharge of Ib Golgi tendon organ afferents and the steady-state tetanic tension generated by activating motor units. This question has been re-examined by recording the responses of individual tendon organs to tetanic, isometric contractions of one or more motor units from the peroneus tertius muscle of anaesthetized cats. 2. In three experiments, seventy-three individual tendon organ-motor unit interactions were recorded. The motor units were stimulated at 30-150 s-1 and for each tendon organ-motor unit pair a linear relationship was found between steady-state tetanic tension and Ib afferent discharge. The slopes of these relationships (the static sensitivities) were steepest for the weakest units. 3. When motor units were stimulated in combination, the relationship between discharge frequency and plateau tension was again linear but the static sensitivities were generally much lower than for single units and approached 1 impulse s-1 g-1. 4. Expression of these relationships in terms of the relative tensions generated revealed that the tendon organs were activated most strongly by the IIb muscle fibres, the static sensitivities being reduced by unloading effects. 5. The linear relationships observed during stimulation of single, and groups of, motor units suggest that the patterns of discharge from the tendon organs can mirror the steady-state contractile tensions within the muscle.

Animals↗
PubMed1994

Pulmonary circulation evaluation before cavopulmonary connections: the cavopulmonary bypass.

The outcome of Fontan-type procedures is dependent on several risk factors, among which pulmonary vascular resistances (PVRs) are an important component. Preoperative calculation of PVR entails several potential sources of error, particularly in patients with pulmonary atresia or multiple sources of pulmonary blood flow. In an attempt to develop a reliable test that accurately assesses the hemodynamic patterns of the pulmonary vascular bed before a Fontan procedure, a simulation of Fontan-type circulation was achieved in 13 patients by a partial cardiopulmonary bypass between the main pulmonary artery and both venae cavae (cavopulmonary bypass). During cavopulmonary bypass, pressures and resistances were recorded. Immediately after cavopulmonary bypass, the circulation was converted to standard cardiopulmonary bypass and the cavopulmonary connection was carried out. Preoperative pulmonary vascular resistance indexes were assessed roughly by the arteriovenous oxygen difference in systemic and pulmonary beds. There was no correlation between preoperative and perioperative calculations of pulmonary vascular resistance indexes (r = 0.24; p = not significant). Hemodynamic data available for all patients then were correlated to the early postoperative outcome assessed by a subjective four-point scale. A positive, significant correlation was found with intraoperative PVR (r = 0.90; p < 0.001), indexed PVR (r = 0.90; p < 0.001), and the pulmonary to systemic vascular resistance ratio (r = 0.98; p < 0.0001). Two of 13 patients had a 4-mm fenestration in the atrial baffle. No mortality or morbidity was related to the procedure. The absolute values of PVR and pulmonary vascular resistance indexes were strikingly higher than generally admitted for this type of procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Primary and secondary afferent discharges from the same spindle during chain fibre contraction in cat tenuissimus muscle.

Pairs of Ia and II afferent fibres supplying primary and secondary endings lying in the same tenuissimus spindles were prepared in barbiturate anaesthetized cats in order to compare the variability in the rhythm of discharge of the two endings during responses elicited by the contraction of different intrafusal muscle fibres, especially by chain fibres. In these spindles, the intrafusal muscle fibres supplied by single static gamma-axons were identified with a recently developed technique based on the types of primary ending activation observed during gamma stimulation at 30 and 100 stimuli/s. The responses of the secondary endings to contraction of chain fibres either alone or with bag2 fibres were smaller and much more regular than the responses of the primary endings lying in the same spindles. This difference is probably related to the position of secondary endings along the intrafusal muscle fibres and to the mechanical properties of the muscle fibre regions on which the terminals lie. The dynamic properties of the encoding site of primary afferent impulses probably contribute to the difference. The different degrees of variability observed among secondary ending responses elicited either by chain fibres alone or by chain and bag2 fibres are not related to the type of activated intrafusal muscle fibres.

Animals↗
PubMed1994

Distribution of static gamma axons in cat peroneus tertius spindles determined by exclusively physiological criteria.

1. The intrafusal muscle fiber(s) activated in cat peroneus tertius spindles by single static gamma (gamma s) axons were identified by exclusively physiological criteria based on the different contractile properties of chain and bag2 fibers. 2. The identification rested both on the features of primary ending discharges observed during gamma s electrical stimulation at a rate of 30 pulses per second (stimulation at 30/s) and on cross-correlograms constructed during stimulation at 100/s. Three types of primary ending activation could be distinguished. 3. Type F (fast) activations are characterized, at 30/s, by either a 1-to-1 driving or a very irregular increase in firing arising from a level close to the frequency of stimulation and by the presence in cross-correlograms of significant peaks. They are ascribed to chain fibers whose contractions, at 30/s, present large oscillations and, at 100/s, are still incompletely fused. 4. Type S (slow) activations are characterized, at 30/s, by a sustained and generally regular increase in firing and by the absence of significant peaks in cross-correlograms constructed during stimulation at 100/s. They are ascribed to bag2 fibers whose contractions are nearly fused at 30/s and completely fused beyond 60-70/s. 5. Type M (mixed) activations are characterized, at 30/s, by an irregular increase of discharge above a level distinctly higher than the frequency of stimulation and by the presence of significant peaks in cross-correlograms. They are ascribed to the coactivation of chain and bag2 fibers for two reasons: first, they have some features of both type F and type S activations; and second, they are readily reproduced by stimulating together two axons supplying the same spindle, one exerting a type F activation, the other a type S activation. 6. In seven experiments the distribution of 42 single gamma s axons was determined by observing the type of activation they exerted on several spindles (from 3 to 6). Thirty-five axons (83%) were classified "nonspecific" because the type of activation (F, S, or M) varied from one spindle to the other. Seven axons (17%) were classified "specific" because the type of activation was the same in all spindles: either type F for five axons (12%) or type S for two axons (5%). A statistical analysis of the distribution of all activations showed that the proportions of specific axons were not significantly different from those predicted by chance.

Animals↗
PubMed1994

Surgery for tetralogy of Fallot at less than six months of age.

Absence of consensus persists regarding the optimal procedure and timing for the surgical treatment of young infants with symptomatic tetralogy of Fallot. From 1987 through 1992, 56 patients with tetralogy of Fallot were operated on at less than 6 months of age. Forty-one patients (median age 2.9 months) underwent primary repair and 15 (median age 2.4 months) underwent initial palliation. Mean follow-up was 24.2 +/- 16.4 months. No strict protocol was used but patients who received initial palliation were younger, had a smaller pulmonary arterial tree, or had anomalous coronary artery. Two patients died (overall mortality 3.6%; 95% confidence limits 0% to 11%), one after initial palliation (6.7%), and one after primary repair (2.4%) (P = 0.47). Eight of the 15 patients who received initial palliation underwent repair and had an increase in pulmonary anulus size at the time of definitive repair (mean difference Z-value = 2.2 +/- 1.6 standard deviation; p = 0.006). Transannular patch was required in 50% of patients who underwent repair (56% among patients having primary repair versus 13% for patients having initial palliation; P = 0.03). Five patients underwent reoperation. Early primary repair of symptomatic tetralogy of Fallot was achieved with a low mortality rate and is the preferred protocol. Initial palliation remains indicated in case of associated cardiac anomaly, very low weight, or severely hypoplastic pulmonary artery tree.

Age Factors↗
PubMed1994

[Cardiac transplantation for old congenital heart diseases after multiple surgery].

Of the 100 consecutive patients undergoing cardiac transplantation between January 1988 and October 1993, 4 patients had terminal cardiac failure related to congenital heart disease after multiple prior palliative procedures (transposition of the great arteries, N = 1, tricuspid atresia, N = 1, single ventricle, N = 2). The prior palliative or curative operations (average 3.75 procedures per patient) modified essentially the systemic venous return and the pulmonary arteries. The technique of "subtotal" cardiac transplantation enabled anatomical reconstruction without prosthetic material in all cases by extensive usage of the donor tissue. There was no hospital mortality. There were no specific postoperative complications. The long-term results were comparable to those of the rest of the transplanted population. Patients with congenital heart disease in a terminal condition should be considered as candidates for cardiac transplantation. The difficulties related to anatomical abnormalities caused by prior surgery may be overcome and should not be considered a contra-indication to transplantation, providing pulmonary arterial resistances are taken into consideration.

Adolescent↗
PubMed1994

[Paraplegia and dissection of the abdominal aorta after closed trauma. Apropos of a case. Current review of the literature (1982-1993)].

A case of dissection with thrombosis of the subrenal abdominal aorta after blunt trauma led to paraplegia and bilateral ischaemia of the lower limbs in addition to acute abdominal signs. A review of the recent literature (1982-1993) revealed 32 reported cases. The patients were predominantly male and most often victims of an automobile accident (18 cases) or crushing trauma (6 cases). The clinical picture associated diverse degrees of abdominal signs, ischaemia and sensorial-motor impairment of the lower limbs. The diagnosis was established immediately on D0 in only 18 cases, early on days 1 to 7 in 4 cases and was late (day 8 to day 30) in 5 cases or very late (beyond day 30) in 6 cases. The difficulty in immediate diagnosis was related to the absent or incomplete vascular symptomatology or the late onset of the first signs. When a lesion of the aorta was suspected, an arteriography, angioscanner or peroperative exploration led to diagnosis. Neurological signs were frequent (10 cases including 8 with paraplegia) and generally related to ischaemia of the peripheral nerves. They may lead to denate from the diagnosis of vascular lesions. Fractures of the intima (17 cases) was the most frequent aortic lesion which also involved fracture of the media in a number of cases. Dissection was associated in 7 cases and complete or partial thrombosis of the aorta in 7. False aneurysms observed in 6 cases are the usual pathological form in cases of late diagnosis. Nearly all of the lesions were subrenal. Damage to abdominal organs was frequently observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Injuries↗
PubMed1994

[The treatment of sterility due to retrograde ejaculation, using implantation of a pericervical sphincter prosthesis. Apropos of a case].

The authors report the case of a 26 year old man consulting for primary sterility due to retrograde ejaculation, which was associated with urinary incontinence secondary to repeated surgery to the bladder neck for neurogenic bladder in a patient with incomplete spina bifida. Pericervical implantation of an AMS 800 artificial sphincter restored perfect continence and normal ejaculation followed by a pregnancy for his wife.

Adult↗
PubMed1993

[Alfa-2b interferon in the treatment of thrombocytosis associated to chronic non leukemic myeloproliferative syndromes].

BACKGROUND: The effect of interferons in the correction of thrombocytosis in chronic myeloproliferative syndromes is well known. In this study the efficacy of alpha-2b interferon in a regimen of induction followed by a phase of sequential maintenance to progressively decreasing doses was evaluated with the aim of knowing the minimum doses necessary to maintain response. METHODS: The response to treatment with alpha-2b interferon was prospectively studied in a group of 37 patients with chronic myeloproliferative syndromes with associated thrombocytosis (excluding chronic myeloid leukemia). Likewise, the toxicity of the treatment was analyzed. RESULTS: Sixty-seven percent of the patients responded (platelets lower than 600 x 10(9)/1) to the daily administration of 3 or 5 MU of interferon. Forty percent of the patients who responded to the daily schedule of administration maintained the response upon receiving 3 doses weekly for 4 months. Half of the 8 patients who received 2 weekly doses of interferon for 4 months continued maintaining the responses. Only two of the 4 patients who received one sole weekly dose during the following 4 months maintained the response. Only one of the 37 patients who initiated treatment underwent progression of the symptoms present at the beginning of the study. Toxicity was high and was the cause of 12 discontinuations of treatment (32% of the patients) during the daily treatment phase (9 patients) or during maintenance of 3 weekly doses (3 patients). No toxicity was observed in the schedule of one or two weekly doses. CONCLUSIONS: Alpha-2b interferon is effective in the treatment of thrombocytosis of the chronic myeloproliferative syndromes (excluding chronic myeloid leukemia) when administered daily and is ever less so when the doses are spaced at 3, 2 or 1 week. The toxicity of interferon treatment is high when administered at affective doses.

Adolescent↗