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Biomedical subjects

C Berthelin

Publications and source records attributed to C Berthelin.

9 recordsLinked to original sources
PubMed2000

Histological Characterization and Glucose Incorporation into Glycogen of the Pacific Oyster Crassostrea gigas Storage Cells.

In order to investigate glycogen metabolism in the oyster Crassostrea gigas, the distribution of storage cells in the whole animal was studied before histological and biochemical characterization. These cells were found mainly in the labial palps, the mantle, and gonadal area and also in gills and the digestive area. Storage cells from palps, mantle, and gonad presented the same morphological features and the same seasonal glycogen variations. Storage cells were isolated from the labial palps and the mantle plus gonadal area of the oyster by enzymatic dispersion and centrifugation through discontinuous Percoll gradient. These cells have a modal density of 1.043 g/ml. An ultrastructural study confirmed that glycogen is present in the cytoplasm either as fine particles or sequestered within vesicles. Glucose incorporation into glycogen was evaluated in vitro using [U-(14)C]glucose: the incorporation in isolated cells increased linearly for at least 8 hours, was proportional to the cell concentration, and showed saturation kinetics with respect to the exogenous glucose concentration.

Journal Article↗
PubMed2000

Storage metabolism in the Pacific oyster (Crassostrea gigas) in relation to summer mortalities and reproductive cycle (west coast of France).

We describe seasonal changes in the biochemical composition of digestive gland, adductor muscle and gonad and surrounding mantle area in Crassostrea gigas from the Western Atlantic coast of France. Seasonality in histology of storage tissues and glycogen storage capacity in isolated vesicular cells were also studied. Proteins, the main muscle components did not contribute to the gametogenetic effort. Glycogen and lipids were stored in the digestive gland, gonad and surrounding mantle area during the wintering period and the gonad and surrounding mantle area represented the main storage compartment supplying the reproductive effort. Gametogenesis in spring and summer was associated with an increase in lipid and protein contents and took place at the expense of glycogen reserves. Histological study of storage tissue in the gonad led us to define four seasonal stages of storage tissue development. In vitro, glycogen storage capacity in isolated vesicular cells was high from November to March and markedly reduced during gametogenesis, decreasing below detectable levels after spawning. This physiological state should be taken into account with relation to summer mortalities occurring in commercial growing areas.

Animals↗
PubMed1991

[Accidental poisoning with podophyllin: a case with study of peripheral nerve].

A 53 year-old veterinary surgeon accidentally ingested 0.8 g of podophyllin. Twelve hours later, he was deeply comatose, with clinical and EMG signs of extensive axonal sensorimotor and autonomic peripheral neuropathy. In addition, transient bone marrow and hepatic toxicity occurred. The coma lasted 2 weeks. Systemic and neurological disturbances started to improve at 3 months post-onset, but the patient died four months later from gastro-intestinal bleeding. Sural nerve biopsy showed loss of myelinated fibers and signs of axonal degeneration with type E teased fibers. The cytoplasm of Schwann and endothelial cells was vacuolated and swelled. Diffuse interstitial aedema was noted. Podophyllin acts as a spindle poison, binds microtubular proteins and inhibits axoplasmic flow.

Accidents↗
PubMed1989

[Familial myopathy with "cytoplasmic body" (or "spheroid") type inclusions, disclosed by respiratory insufficiency].

Three patients, 72, 45 and 18 years old belonging to 3 successive generations presented with respiratory insufficiency. The clinical onset was at about 40 years of age in the two older patients and at 18 years in the youngest one. Serum enzymes of muscle origin were within normal range as well as leucocyte maltase activity. The muscle biopsy in all three patients showed numerous cytoplasmic (spheroid) bodies within type I muscle fibers. Familial cytoplasmic body myopathy with familial incidence has rarely been reported and still more rarely has been revealed by respiratory insufficiency in adult life.

Adolescent↗
PubMed1985

Prilocaine in arthroscopy: clinical pharmacokinetics and rational use.

Prilocaine pharmacokinetics were determined in 60 patients receiving the drug by two different routes of administration (intra-articular and subcutaneous) during arthroscopy under local anesthesia with controlled pressure irrigation. Resorption of prilocaine by subcutaneous tissues was slow and did not lead to high serum levels. On the contrary, prilocaine resorption by the synovium was fast and induced a sharp serum peak (265.8 +/- 163.5 ng/ml) in the hour after the end of the examination. The drug was completely eliminated from the blood after 24 hours, as the prilocaine t1/2 is about 5 hours. The first procedure was perfected to reduce the risk of methemoglobinemia, which occurred in four of 105 patients. Applied pressure was lowered to 100 mm Hg to prevent the escape of anesthetic solution into the soft tissue of the leg, the prilocaine concentration was reduced to 1 gm/L, and the arthroscope was only set up after a delay to allow the intra-articular anesthetic effect of prilocaine to become established. So far, 200 arthroscopies have been performed with this improved protocol without any problem.

Adolescent↗
PubMed1984

[Peripheral nerves in a case of lead neuropathy].

A patient developed lead neuropathy with an asymmetrical distal weakness of the four limbs and sensory signs. Tap water contained high amounts of lead and biopsy confirmed the intoxication. The electromyogram was altered from the onset of the disorder and was still abnormal one year after treatment with EDTA, which however brought frank improvement. Biopsies were taken from nerves of the upper and lower limbs. Examination of teased nerve fibers showed the predominance of fibers of small diameter and segmental demyelinization with signs of remyelination in the lower limbs. Semi-thin sections demonstrated depopulation of large myelinated fibers, regeneration clusters and Schwann cells with globular nuclei. Electron microscopy showed myelin sheath alterations and neuritic lesions, some hyperactive Schwann cells. Main alterations were seen in basal membranes of Schwann cells of unmyelinated fibers and endoneuronal capillaries. Such alterations to our knowledge have never been reported in human peripheral lead neuropathy, but have been described after experimental intoxication. These findings together with recent experimental studies allow a discussion about the site of entry of lead into the nerve and about its site of action on the various constituents of the peripheral nerve.

Adult↗
PubMedDate not supplied

Inclusions in familial cytoplasmic body myopathy are stained by anti-dystrophin antibodies.

We report here for the first time positive anti-dystrophin labelling of inclusions in three cases belonging to the same family affected by familial cytoplasmic body myopathy (CBM). Inclusions are also stained, as reported previously, by anti-actin antibodies. The anti-desmin reaction was negative in the centre of cytoplasmic bodies (CB) but showed an enhancement of staining in the peripheral part. Abnormal sarcoplasmic staining of fibres with CB was also observed with that antibody. Anti-vimentin antibody labelling was negative. At present, the significance of this labelling by anti-dystrophin antibodies is unknown, but will open new fields for further investigations in an attempt to understand CB pathogenesis.

Actins↗