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Biomedical subjects

C Boisseau

Publications and source records attributed to C Boisseau.

At least 19 recordsLinked to original sources

Long-range molecular resonances in a cold Rydberg gas.

We present evidence for molecular resonances in a cold dense gas of rubidium Rydberg atoms. Single UV photon excitation from the 5s ground state to np Rydberg states (n=50-90) reveals resonances at energies corresponding to excited atom pairs (n-1)d+ns. We attribute these normally forbidden transitions to avoided crossings between the long-range molecular potentials of two Rydberg atoms. These strong van der Waals interactions result in avoided crossings at extremely long range, e.g., approximately 58 000 times the Bohr radius (a(0)) for n=70.

Journal Article↗

Chronic inflammatory demyelinating polyneuropathy associated with dysglobulinemia: a peripheral nerve biopsy study in 18 cases.

The possible occurrence of chronic inflammatory demyelinating polyneuropathy (CIDP) in association with an identified dysglobulinemic status is recognized and a causal relationship between the two has been suggested. We had the opportunity to study 18 patients presenting with CIDP and dysglobulinemia. This was an IgG monoclonal gammopathy (IgG MG) in 8 cases, an IgM monoclonal gammopathy (IgM MG) in 8, an IgG-IgM biclonal gammopathy in 1 case and an IgM monoclonal cryoglobulinemia in another. A peripheral nerve biopsy specimen was available for all patients and the morphological findings in these specimens in the cases of CIDP with IgG MG or cryoglobulin did not differ from those without, whereas characteristic features were observed in the cases of CIDP with IgM MG and anti-myelin associated glycoprotein activity.

Aged↗

[Abdominal paraesophageal bronchogenic cyst].

We report a case of abdominal paraesophageal bronchogenic cyst in a 19 year-old patient who complained of dysphagia. Based on this exceptional finding, the authors state overview the pathogenic theories and the histologic features which distinguish para-esophageal bronchogenic cysts from duplications. Preoperative diagnosis is difficult, but endoscopic ultrasound seems to be the imaging method of choice.

Adult↗

Expression of RNA isolated from the water-shunting complex of a sap-sucking insect increases the membrane permeability for water in Xenopus oocytes.

The highly specialized membranes of the filter chamber found in the digestive tract of some homopteran insects could represent a favorable material for characterizing water channels. In order to demonstrate that membrane proteins of this epithelial complex serve as water channels, we have investigated the membrane permeability for water in Xenopus oocytes injected with RNA isolated from the filter chamber. Volumes of oocytes injected with filter chamber RNA were increased by 15% following a 16-min osmotic shock, while volumes of oocytes injected with RNA from midgut not of filter chamber or with water were increased only by 8.5 and 10%, respectively. This significant difference in oocyte swelling leads us to conclude that RNA isolated from the filter chamber contains mRNA coding for water channel proteins.

Animals↗

Experimental reduction of portal hypertension by mechanical increase of liver portal flow.

Studies on the isolated perfused rat liver demonstrated that an increase in portal pressure is associated with an increase in the portal blood flow in normal and in cirrhotic livers. In two pigs with portal hypertension mesenteric portal pressure was lowered by mechanically increasing the liver portal blood flow by means of a balloon pump around the portal vein.

Animals↗

Observations on the intestinal colonization by Pseudomonas aeruginosa in newborn infants.

We studied the intestinal flora of 23 newborns, whose meconium had yielded a pure culture of Pseudomonas aeruginosa on blood agar medium. Twelve infants had a single serotype of P. aeruginosa in their meconium, 10 had a second serotype and the last infant was carrying three distinct ones. The maximum levels of P. aeruginosa observed during the first week of life were variable among the infants: 1 x 10(3) to 1 x 10(10) CFU/g of stools. The levels diminished progressively afterwards, and after 1 year of age only 1 of the 13 infants examined remained a carrier of P. aeruginosa. In 11 infants a second or a third serotype occurred during the course of the study. The serotypes that appeared secondarily always disappeared before the initial ones. Antibiotics: ampicillin + gentamicin or cefotaxime + netilmicin and colistin which were given to 8 infants had no clear effect on P. aeruginosa levels. Four infants had delayed colonization by Escherichia coli of greater than or equal to 10 days. All 4 had high levels of P. aeruginosa: 1 x 10(7) to 1 x 10(10) CFU/g stool, and antibiotic therapy, rendering it impossible to assess which was the cause of this delay. This colonization by P. aeruginosa did not lead to any clinical trouble.

Cefotaxime↗

Reproductive effects of the anti-cancer drug procarbazine in male rats at different ages.

Rats aged 10 days (Exp. A), 45 days (Exp. B) and 70-90 days (Exp. C) were given procarbazine intraperitoneally at doses of 30 mg/kg/day for 5 or 9 weeks (Exps A, B, C), or by gavage at doses of 5 mg/kg/day (equivalent to the therapeutic dose in man) and 50 mg/kg/day, for 9 weeks (Exp. B). A significant mortality rate was noted in immature rats (Exp. A) and in animals receiving 50 mg/kg/day orally (Exp. B). In all groups the rate of body weight gain and the weights of the testes and epididymides were reduced. Procarbazine produced disruption of the normal spermatogenetic architecture that was very severe or total in immature rats (Exp. A) and in rats given the drug at 30 mg/kg/day for 9 weeks and the highest dose (50 mg/kg) in Exp. B. Disruption of spermatogenesis was only partial in the other experimental groups. The number of Sertoli cells was not affected by the different treatments, but a Sertoli cell dysfunction (vacuolization, decreased ABP and elevated FSH concentrations), most probably secondary to germ cell degeneration, was demonstrated in those rats presenting the most severe disruption of spermatogenesis (Exp. B: i.p. and gavage, 50 mg/kg for 9 weeks). Leydig cells, always present in the interstitium, were moderately affected (decrease in serum testosterone values) in some groups at all ages whereas epididymal sperm reserves were decreased after 9 weeks (Exp. B: 30 mg/kg, i.p.; 5 and 50 mg/kg, gavage). Moreover, there was a marked fall in the number of fetuses per female mated by males in all experimental groups. We conclude that the effects of procarbazine on male reproductive function were independent of the route of administration, greater before puberty and proportional to the dose administered as well as to the duration of the treatment.

Animals↗

[Study of erythrocyte bilirubin. Evaluation of the risk of kernicterus].

351 analysis of bilirubin binding by erythrocytes (BE) and of non conjugated bilirubin (NCB) are realised. 15 analysis have an increasing of the value: 6 with NCB and BE high with EST; 3 with NCB high and BE normal with EST; 6 with NCB high and BE normal without EST and any complication.

Bilirubin↗

Amyloid neuropathy and multiple myeloma. Ultrastructural and immunopathological study of two cases.

Report of 2 patients suffering from sensory peripheral neuropathy and multiple myeloma. In 1 case, peripheral neuropathy occurred several months before the appearance of multiple myeloma. A peripheral nerve biopsy exhibited numerous amyloid deposits within the endoneurium. Amyloid deposits have been estimated to occur in 15% of cases of multiple myeloma, but only 4 other detailed observations of amyloid deposits within the endoneurium have been reported in the literature. Other mechanisms might be involved since most peripheral neuropathies associated with multiple myeloma do not exhibit any amyloid deposits.

Amyloidosis↗

[Giant diverticulum of the sigmoid colon. A rare complication of colonic diverticulosis. Review of the literature apropos of a case].

The authors report a case of giant diverticulum of the sigmoid colon, a very rare complication of diverticulosis of the colon, since only 38 cases have been reported in the literature. The diverticulum was seen at barium enema in a 66-year-old man complaining of digestive symptoms consisting of lower abdominal pain, tenesmus, diarrhea and fever. Segmental resection of the sigmoid colon including the site of implantation of the diverticulum with end-to-end anastomosis at the same operative stage led to definitive cure. On the basis of a study of the literature, the authors define the clinical, diagnostic and pathogenic characteristics of the condition.

Aged↗

[Amphibian jelly envelopes (proteins secreted by the oviduct) and their role in fertilization].

The jelly envelopes, surrounding amphibian eggs and playing a major part in the initial steps of fertilization, are deposited around the eggs as they traverse the different parts of the oviduct. These envelopes form 5 to 8 morphologically distinct layers according to the species, i.e. in Anura and Caudata they are organized differently, and are composed of about ten different macromolecular components (glycoproteins). The innermost layer is rich in sulfate and poor in fucose, a carbohydrate abundant in the other layers. This is due to a fucosyltransferase deficit in the cranial part of the oviduct secreting this layer. The cranial and the medial oviduct secretory products show a lectin carbohydrate-like reaction which is pH-dependent and can be inhibited by carbohydrates like glucuronolactone. This reaction has made it possible to isolate, by affinity chromatography, the main secretory component of the cranial oviduct (Spop). This paper discusses the main functions of the jelly layers of the egg, with particular reference to fertilization. The role of their macromolecular components in sperm capacitation is clear in Anura; experimental investigation in Urodeles is more difficult. We propose several hypotheses to explain the molecular interactions leading to capacitation. Block to polyspermy in amphibians is discussed.

Amphibians↗