Search PubMed⌕ Search

Biomedical subjects

J Petit

Publications and source records attributed to J Petit.

At least 199 records · Page 11Linked to original sources
PubMed1988

Tunnelling of two central venous catheters inserted via a single venipuncture.

Two central venous catheters were inserted into the subclavian or internal jugular vein using a single puncture and tunnelled with two different subcutaneous pathways in 32 critically ill patients; 15 of them underwent this procedure immediately after a tracheostomy. The procedure was carried out without significant technical difficulties. Separate removal of one of the catheters was performed easily in 5 cases. Cultures were positive in 21% of 42 catheters from 21 patients; Staphylococcus epidermidis was isolated from 7 catheters. Separate tunnelling of two central venous lines inserted via a single venipuncture can be used in critically ill patients needing multiple central venous access.

Adult↗
PubMed1988

[Epidural analgesia after thoracic surgery: morphine versus buprenorphine].

A double-blind study was carried out to assess the efficiency and possible side-effects of a single epidural injection of either morphine or buprenorphine at equipotent doses after elective thoracic surgery. The series included 24 patients aged 53.7 +/- 11.4 years; 13 underwent a lobectomy and 11 a pneumonectomy. 6 h after the last intravenous injection of fentanyl, the patients were randomly allocated to one of three equal groups. They received an epidural injection at T8-9 or T9-10 level of either 100 micrograms.kg-1 morphine (group M) or 6.6 micrograms.kg-1 buprenorphine (group B) or a subcutaneous injection of 0.1 ml.kg-1 normal saline placebo at the same level (group T). The following parameters were measured 20 and 60 min, and every 6 h up to 48 h after the injection: patient wakefulness, respiratory rate, blood gases, pain (according to a verbal scale), FVC and FEV1, adverse effects (euphoria, hallucinations, sweating, facial pruritus, nausea) and atelectasis. The duration of surgery, the anaesthetic protocol, the age, weight and height, as well as all the parameters before injection were similar in all three groups. There was a fall in pain intensity from the 20th min to the 24th hour in group M and from the 20th min to the 36th hour in group B, significant for both groups when compared with group T. Similarly, there was a prolonged increase in FEV1 in both groups M and B. There was no case of severe respiratory depression; PaCO2 was increased at the 1st hour (+0.3 +/- 0.6 kPa) in group B and at the 6th hour (+0.5 +/- 0.7 kPa) in group M.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Proportion of fatigue-resistant motor units in hindlimb muscles of cat and their relation to axonal conduction velocity.

1. A study of motor units to hindlimb muscles of cat has been made, with as complete a sample as possible of the motor axons to an individual muscle. In single experiments as much as 95% of the motor supply to a muscle has been examined. 2. The following muscles have been studied: peroneus brevis, peroneus tertius, peroneus longus, plantaris, gastrocnemius medialis, soleus, tenuissimus and lumbricalis superficialis. 3. Units were identified as slow resistant (S), fast resistant (FR), fast fatigable (FF) and fast intermediate (FI). The proportion of various motor unit types differs from one muscle to another. There is also some variation in the proportions to a given muscle from one animal to another. With the exceptions of soleus, which is entirely slow resistant, and gastrocnemius, which has relatively fewer resistant units, most muscles contain 60% or more of resistant (S and FR) units. 4. The conduction velocity ranges of FF, FR and FI units overlapped. There was little overlap between the conduction velocity ranges of these F units and of S units. 5. In individual experiments there was a strong and significant positive correlation between the logarithm of maximal tetanic tension and axonal conduction velocity in S and in S+FR units. In terms of contractile response the total fatigue-resistant population appeared to be a continuum. The correlation coefficient between maximal tetanic tension and conduction velocity was also high in the totality of units of all types, although within the FF group there appeared to be little or no correlation. In pooled data there was much more scatter and these relations were less clear. This resulted largely from differences in the ranges of axonal conduction velocity for a given motor unit type from one animal to another. 6. There was a highly significant negative correlation between isometric twitch contraction time and axonal conduction velocity in individual experiments. This relationship could also be seen, but less clearly, in pooled data. 7. The possible bases for these relationships are discussed.

Animals↗
PubMed1988

Effects of muscle shortening on the responses of cat tendon organs to unfused contractions.

1. The discharges from individual Golgi tendon organs of peroneus tertius and brevis muscles were recorded in anesthetized cats. Responses to unfused isometric contractions of single motor units and combinations of motor units were compared with responses to contractions eliciting muscle shortening (i.e., shortening contractions). 2. In 75% of the examined instances, the effect of muscle shortening during unfused contractions was a slight decrease in tendon organ activation, in keeping with the reduction of contractile tension recorded at the muscle tendon. In other instances there was either no change in tendon organ response or, in less than 10% of instances, a slight increase For two motor units eliciting similar activation of a given tendon organ under isometric conditions, the effect of shortening contraction was not necessarily the same. 3. The reductions observed in tendon organ discharges upon muscle shortening were less than proportional to the reductions of contractile tension and difficult to correlate with the properties of motor units, as determined under isometric conditions. The present observations suggest three main reasons for this lack of relation. 4. The first reason depended on the properties of motor units, in that the relation between length changes and tension changes was not the same for all units. Two motor units developing similar isometric tensions did not necessarily produce the same degree of muscle shortening. Some units produced relatively significant shortening without much loss of tension. 5. Second, the dynamic sensitivity of tendon organs is known to exert a major influence on their responses to isometric unfused contractions, accounting for 1:1 driving of discharge during tension oscillations and high frequency bursts upon abrupt increase of tension. Although less tension was produced and the rate of tension development was slower in shortening contractions, similar manifestations of the dynamic sensitivity of tendon organs were observed. In such cases, the responses of tendon organs were the same whether or not the muscle shortened during contraction. 6. Third, when several motor units were stimulated in combination, the unloading influences of in-parallel units were facilitated by muscle shortening so that unloading effects, which were hardly visible under isometric conditions became evident during shortening contractions.

Animals↗
PubMed1988

[Surgery for incomplete atrioventricular canal. Mid-term follow-up apropos of 128 patients].

Among 128 consecutive patients operated upon between 1972 and 1984 at the Marie-Lannelongue Surgical Centre for incomplete persistent atrioventricular canal, 102 could be followed up for periods ranging from 18 months to 11 years. Of the 23 patients lost sight of, 19 were foreigners. One patient died during the first postoperative month and two died during the following five months; there was no death thereafter. One patient developed complete atrioventricular block immediately after surgery. At the end of the follow-up period, three patients had been reoperated upon for disinsertion of the patch on the ostium primum associated in one case with massive mitral regurgitation; two complete atrioventricular blocks requiring permanent pacing had occurred some time after surgery; five patients had presented with late atrial dysrhythmia, and only six patients had signs of heart failure primarily due to residual mitral regurgitation. At radiography, the cardiothoracic ratio was reduced in 74 p. 100 of the cases from 0.60 +/- 0.08 to 0.53 +/- 0.05 (p less than 0.001), and the earlier the operation had been performed, the greater the reduction in cardiothoracic ratio (p less than 0.05). A mitral regurgitation murmur was observed in 72 p. 100 of patients immediately after surgery and in 82 p. 100 of patients at the end of the follow-up period. The murmur was usually weak (79 p. 100) with a tendency to remain stable (44 p. 100) or to increase in intensity (43 p. 100, but reoperation was necessary in only one case.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1988

Pharmacokinetics of cyclophosphamide administered alone or in combination with vindesin or cisplatin in 5 patients with bronchial adenocarcinoma.

The pharmacokinetics of cyclophosphamide (CPH) administered intravenously at doses between 200-400 mg alone or in combination with vindesin (VDS) or cisplatin (cisPt) were studied in 5 patients who had bronchial adenocarcinoma, with normal liver and kidney functions. The linearity and the reproducibility of CPH kinetics were confirmed and its pharmacokinetic parameters were found to be unaffected by simultaneous or sequential administration of either vindesin or cisplatin. Total clearance was 7.69 +/- 3.53 1.hr-1 for CPH administered alone and 6.76 +/- 1.63 1.hr-1 for CPH administered with vindesin. Biological half-life was 4.3 +/- 1.5 hr (CPH alone) and 5.1 +/- 2.2 hr (CPH + VDS).

Adenocarcinoma↗
PubMed1987

[Disclosure of a fatal pheochromocytoma during general anesthesia].

A case is reported of a phaeochromocytoma revealed during a general anaesthesia by a sudden hypertensive crisis associated with acute pulmonary oedema and signs of extreme sympathetic stimulation (bilateral mydriasis, piloerection, peripheral vasoconstriction). Aortic angiography revealed the tumour lying in an ectopic retroperitoneal situation and spasm in the superior mesenteric arterial territory. The patient died at the thirtieth hour from septic shock due to necrotizing colitis.

Adrenal Gland Neoplasms↗
PubMed1987

[Effects of intravenous naloxone on the secondary effects and analgesia after epidural injection of fentanyl].

On demand intravenous naloxone reverses respiratory depression following epidural morphine but does not have any effect on analgesia. This study aimed to assess the action of a preventive naloxone infusion on the side-effects and analgesia induced by epidural fentanyl. Sixteen patients were studied. Three had isolated uncomplicated flail chest. The thirteen others had undergone thoracotomy, and were included in the protocol at least 6 h after extubation. All patients had two epidural injections, they received an intravenous infusion of either 10 micrograms.kg-1.h-1 naloxone after a 400 micrograms bolus (group F + N) or 5% dextrose (group F), which was randomly allocated. In group F, but not in group F + N PaCO2 increased from the 15th min to the 4th, and sedation occurred from the 15th min to the 6th h. A significant and similar pain relief was noted in both groups. Duration of analgesia was not statistically different in the two groups. This preventive action of intravenous naloxone on the supraspinal adverse effects of epidural fentanyl was not accompanied by a reduction in analgesia. This could lead to widespread use of this analgesic technique.

Adult↗
PubMed1987

Collagen IV staining pattern in bladder carcinomas: relationship to prognosis.

A prospective study of type IV collagen in urothelial tissues was undertaken using an immunoperoxidase method on 125 ethanol fixed specimens. In normal and non cancerous urothelium, the basement membrane was continuously stained and the same pattern was seen in the 27 superficial carcinomas. In the 48 invasive bladder carcinomas, we observed two patterns of staining for collagen IV: in the first one, the staining line was conserved or partially fragmented (28 tumours), while in the second one the staining line was widely fragmented or absent in more than 5% of the tumour area (20 tumours). We found a highly significant statistical correlation between the pattern of staining and short term prognosis. Twenty-nine patients had an assessable follow-up of three years at least. All 16 patients with pattern I staining were alive at two years while only two out of 13 patients with pattern II staining survived two years (P less than 0.0001). At three years, all the patients with pattern II staining died while 11 patients with pattern I were still alive (P less than 0.001). These data provisionally indicate that the type IV collagen staining pattern may be of prognostic value in assessing the short term behaviour of invasive bladder carcinomas. It is thus logical to envisage that the treatment decisions may be influenced by the results of collagen IV staining.

Basement Membrane↗
PubMed1987

Physical and aerodynamic features of the Bordeaux voice prosthesis.

Performance of a voice prosthesis, used to restore speech in patients following total laryngectomy, was evaluated by measuring in vitro, as well as in vivo, airflow resistances. The pressure-flow characteristics of the device were analyzed using the standard pressure-flow diagram (to calculate airway resistance) and a Moody plot (to determine the different flow patterns). The flow rate and the pressure drop were measured with a Fleisch pneumotachograph and a variable reluctance transducer, respectively. Total device resistances were found in the range of 34-50 cm H2O/L/s when the flow-rates ranged from 0.05 to 0.35 L/s. Comparison of these resistances with those of other commercially available devices showed that our voice prosthesis had the lowest resistance.

Airway Resistance↗
PubMed1987

Activation of cat motor units by paired stimuli at short intervals.

1. In adult cats, paired stimulations at short intervals were applied in ventral root filaments to single motor axons innervating the peroneus tertius muscle. Paired impulses were recorded from the muscle nerve simultaneously with the electrical and mechanical responses of the muscle portion of the motor unit (muscle unit). The interstimulus interval was gradually reduced in order to determine the minimum compatible with a full activation of the muscle unit by the second impulse. 2. For motor units of all physiological types, this minimum stimulus interval was the shortest interval allowing initiation and conduction of two impulses in the axon, that is, the absolute refractory period for conduction. Its duration ranged between 0.58 and 0.88 ms, displaying no correlation with the axonal conduction velocity. 3. The amount of tension enhancement produced by paired stimulations at the shortest interval varied with the type of the motor unit: it was largest for fast-fatigable units, intermediate for fast-resistant units and smallest for slow units. 4. Paired impulses elicited by paired stimulations at the shortest possible interval arrived near the muscle at a longer interval because the second impulse was conducted at a slower velocity. The minimum interval between arrival of impulses at the muscle depended on conduction velocity and on conduction distance. 5. In motor axons to peroneus tertius, paired impulses leaving the spinal cord at a mean interval of 0.78 ms arrived near the muscle separated by a mean interval of 1.90 ms. Since such an interval always allowed full activation of the muscle unit by the second impulse, this interval is longer than the refractory period of motor units in this muscle.

Action Potentials↗
PubMed1987

[Endoluminal mitral valvuloplasty in young adults and children. Apropos of 10 cases].

Between April 1 and May 15, 1986, transluminal dilatation of the mitral valve was performed at the Marie-Lannelongue Hospital, near Paris, in 10 patients aged from 12 to 48 years (mean 25,3 years) suffering from rheumatic mitral stenosis with supple valve leaflets. The procedure, carried out under local anaesthesia, included trans-septal catheterization followed by installation of one, then usually two balloons opposite the mitral orifice. The total diameter of the balloons was often greater than that of the mitral annulus. No haemorrhage, embolism or arrhythmia was observed. A significant left-to-right shunt, evaluated by radioisotope exploration with technetium pyrophosphate performed on the 8th day, was present in only one patient. The LV-LA end-diastolic gradient fell from 14.4 +/- 9.8 to 4.6 +/- 3.4 mmHg (p less than 0.01). The mean pulmonary arterial pressure was reduced less significantly from 39.9 +/- 18.4 to 27.2 +/- 11.3 mmHg (p less than 0.02). The cardiac output was only moderately increased from 2.52 +/- 0.48 to 2.88 +/- 0.66 l/min/m2. The mitral valve area, measured from the smaller axis on 2-dimensional echocardiography, more than doubled, reaching a mean value of 1.99 +/- 0.56 cm2. This figure was confirmed by the reduction, at Doppler velocimetry, of the gradient half-regression time from 267 +/- 62 to 118 +/- 46 ms (p less than 0.01). Similarly, the end-systolic gradient evaluated by Doppler, fell from 17.5 +/- 8.9 to 5.3 +/- 4.7 mmHg (p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

[Congenital diverticulum of the lower choledochus. Apropos of a case with intraduodenal development].

The onset of subicterus in a patient revealed the presence of a congenital diverticulum of lower common bile duct of intraduodenal development. A part from the rarity of this lesion this case is of interest due to the complete range of ultrasound, endoscopic and CT scan imaging performed, the association of a common mesentery and the surgical technique employed. The latter comprised exeresis by transduodenal approach and a side-to-side choledocho-duodenal anastomosis through the intermediary of the diverticular sleeve. The nosology and differential diagnosis of diverticulum of lower common bile duct are discussed and data from a literature review used to describe diagnostic, etiopathogenic and histopathologic aspects as well as complications and treatment of this type of congenital dilatation of lower biliary tract.

Common Bile Duct Diseases↗