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Biomedical subjects

J Perrin

Publications and source records attributed to J Perrin.

At least 55 records · Page 3Linked to original sources
PubMed1986

Hepatitis B immunization of newborns according to a two dose protocol.

Experimental hepatitis B immunization trial in newborns was carried out in Burundi. Newborns were randomly divided into vaccine and control groups. Vaccinated newborns were given two injections of hepatitis B vaccine: one at birth and another 2 months later. A booster dose was given at 12 months of age. Results obtained show that two months after the second dose of HB vaccine, 96.8% of the vaccinated babies had anti-HBs; at the age of one year this figure had fallen to 83.8%. Six months after the booster dose, 95.6% were anti-HBs positive, with a geometric mean titre of 214 mIU ml-1. The anti-HBs responses in these infants was compared to those observed in previous studies performed in Senegal in infants (same protocol) or in newborns (3 dose protocol). The anti-HBs responses were lower in terms of mean titre values in neonates who received the two dose protocol than in older children and in neonates who received three doses at one month intervals. Vaccine efficacy was monitored during a two year period in neonates both immunized and nonimmunized. Protective efficacy was found to be 100% if considering HBsAg positive events and 75% if considering all HBV events (HBsAg and/or anti-HBc positive).

Clinical Trials as Topic↗
PubMed1986

Effect of concomitant antacid administration on plasma cimetidine concentrations during repetitive dosing.

Previous research has suggested that concurrent administration of antacid and cimetidine results in lower than expected plasma levels of cimetidine. Because these studies were all of single-dose design, this study was undertaken to determine the nature of the interaction after repeated administration of both drugs. There was no statistically significant difference demonstrated for any of the pharmacokinetic parameters evaluated in the study. Based on these findings, the previous recommendation that administration of antacid and cimetidine be separated in time may not be necessary.

Adult↗
PubMed1986

[Female transmitters of Duchenne's myopathy: detection by quantitative ultrasonography combined with blood creatine kinase].

Duchenne muscular dystrophy (DMD) is a disease inherited in an X-linked recessive manner. Nothing is yet known about the gene defect involved. The problem of DMD carrier detection is very important and now without satisfactory solution. Presently the best method, for this detection, is the determination of the serum creatine-kinase (CK) level. However about 30% of DMD children's mothers have normal CK levels. In this study we associated CK determination and a new echographic method. This physical investigation is based on the muscle attenuation measurements through the evolution of the running spectral moments. The parameter expressed is the slope of the ultrasound attenuation signal (in decibels by centimetre and by megahertz; dB . cm-1 . MHz-1). We measured this parameter in vivo on the vastus medialis. The use of the chemical technique and of the physical one improves largely the detection of obligate carriers of Duchenne muscular dystrophy than when one of these methods is employed alone. One such combination recognizes 17 out of the 19 obligate carriers in our series. The difference of the results obtained by these two unrelated methods cannot be yet interpreted, but can reflect genetic heterogeneity in DMD and the inactivation of the X chromosomes.

Creatine Kinase↗
PubMed1985

Specular reflector noise: effect and correction for in vivo attenuation estimation.

After reviewing the usual models proposed for the echographic response of soft tissues, we discuss the interaction between the ultrasonic wave and large size obstacles. Structures of this size, specular reflectors, can be found in tissues. The influence of such reflectors on in vivo attenuation measurements is detailed. We point out the importance of the specular echo noise originating from two kinds of reflectors: plane-like and vessel-like reflectors. We present a complete study of their influence on two different algorithms for attenuation estimates: the spectral centroid shift and the narrow band methods. Results are presented on stimulated data, a tissue-mimicking phantom and in vivo muscle data. Different procedures for minimizing the specular echo noise are also discussed.

Humans↗
PubMed1985

[Hepatitis B and primary cancer of the liver in intertropical Africa].

During the past 15 years, a growing body of evidence incriminates hepatitis B virus as the major factor in the etiology of primary liver cancer. Epidemiological studies throughout the world reported a striking correspondence between areas where the frequency of primary liver cancer is high and where HBV infection is hyperendemic. Moreover, primary liver cancer is commonly associated with cirrhosis of the postnecrotic macronodular type. Such data suggested a sequence hepatitis-cirrhosis-PLC. Such sequence was confirmed by extensive serologic testing studies which reported a high frequency of HBV markers in PLC patients compared to matched control groups. Data collected in Senegal, Mali and Burundi on 12,000 individuals stress the importance of HBV infections in these countries, as the high rate of chronic carrier state in patients suffering from liver cirrhosis or primary liver cancer (62-63%) compared to the general population (12-17%). Other HBV markers including anti-HBs, anti-HBc, HBeAg and anti-HBe had no prognostic value in the sequence hepatitis-cirrhosis-PLC. A new HBV seric marker, the HBsAg/IgM complexes, observed in HBsAg positive individuals, is more frequently detected in PLC patients (50%) and cirrhosis (40%) than in healthy HBsAg carriers (14%). These results would indicate that HBsAg carriers are more likely to develop cirrhosis or primary liver cancer when they evidence HBsAg/IgM complexes. In conclusion, the seric markers of evolution towards primary liver cancer are: HBsAg (the highest known risk factor), the presence in such individuals of HBsAg/IgM complexes, and increased values of alphafoetoprotein.

Adolescent↗
PubMed1984

[Vaccination of the newborn against hepatitis B in Burundi].

Vaccination against hepatitis B is carried out at birth in the Bujumbura Hospital in Burundi. The vaccination protocol comprises only two injections, the first being given during the first 48 hours after birth and the second two months later. A booster is given at the age of one year. The results of this vaccination programme are compared with those obtained in a control population. At the time of the booster, 82% of vaccinated subjects had anti-HBs antibodies, compared with 3% of control subjects. Six months after the second injection, all vaccinated subjects had anti-HBs antibodies.

Burundi↗
PubMed1983

Contribution of intercellular links to ultrasonic absorption of liver tissue.

The method discussed aims to characterize the ultrasonic absorption of liver tissues between 3 and 8.75 MHz by the slope of its linear variation with frequency. A transmission measuring device has been used and a data processing system has directly calculated this slope, which is reduced when the strength of intercellular links are lessened by mild treatment with trypsin, although the cells are left intact. This was performed on three batches of Wistar rats and the effect is explained mainly by reduction of the amplitude of relaxation processes dissipating energy in the cells.

Animals↗
PubMed1983

Splanchnic afferent input to the lateral reticular nucleus of the cat.

The afferent input from splanchnic nerves to the lateral reticular nucleus (LRN) was studied in anesthetized cats. The activity of neurons of the parvi- and magnocellular regions of the nucleus was recorded by means of extracellular microelectrodes. The LRN neurons were stereotaxically located and identified by their response to antidromic stimulation of the cerebellar cortex. Activity of the LRN neurons studied was modified by electrical stimulation of the ipsi- and contralateral splanchnic nerves, and by mechanical stimulation of peritoneal receptors. Response latencies to stimulation of the splanchnic nerves were measured, and conduction velocities of peripheral fibers were determined; most of them were myelinated fibers with a small diameter (sub-groups of A- A gamma delta) and were connected with 'peritoneal movement mechanoreceptors'. Numerous convergences were observed. All of the tested neurons which responded to stimulation of the homolateral splanchnic nerve also responded to stimulation of the contralateral splanchnic and to diverse somatic stimulations. In 90% of the neurons tested, a splanchno-cortical convergence (sensory-somatic cortex) was observed. Two possible roles of splanchnic afferents that activate neurons of the LRN were considered: (1) they might, like other spinal inputs, influence LRN and cerebellar control of motor activity; and (2) they might also participate in cardiovascular regulations in which the LRN is involved.

Animals↗
PubMed1982

A lethal, Larsen-like multiple joint dislocation syndrome.

We describe here two isolated cases of lethal, Larsen-like multiple joint dislocation syndrome. Death occurred shortly after birth with pulmonary insufficiency due to tracheomalacia and/or lung hypoplasia. Both had abnormal dermal collagen bundles. In one case, histochemical studies showed abnormal cartilagenous matrix and striking deficiency in the dense collagen bundles of joint capsules; electronmicroscopic studies of the hyaline cartilage of the trachea documented a relative increase of the small, short fibers with decrease of the matrix collagen fibers. This study confirms that this Larsen-like syndrome is a disorder of connective tissue, possibly involving dysmaturity of the collagen fibers, with a predilection for joint capsules and tracheal cartilage. This lethal condition is characterized by pulmonary insufficiency, tracheomalacia, and collagen fiber dysmaturity.

Collagen Diseases↗