Biomedical subjects
Publications and source records attributed to C Allal.
The titration of haemolytic complement in biological liquid cause inconvenient in calculating concentration, it was long and fastidious. We report a fast technic based on measure of hemolysis in microplate++ method, which exploitation of results, it does with an appropriate algorithm.
Detection of oligoclonal immunoglobulins in multiple sclerosis cerebrospinal fluid (MS-CSF) seems to be an important test in the biological diagnosis of the disease. In our laboratory, the classical agarose gel electrophoretic technic allowed the detection of CSF oligoclonal bands in only 40% of the MS patients. This relatively low percentage in comparison with those obtained by other investigators led us to develop a much more resolving electrophoretic technic: an agarose gel isoelectric focusing (IEF) with silver staining. By this method, we detected oligoclonal immunoglobulins in 43 (43%) of 100 MS-CSF exhibiting only polyclonal patterns on classical electrophoresis. Oligoclonal banding appeared particularly in patients with inflammatory type profile (36/60) according to Schuller's classification, but also in those with normal (5/26) or inflammatory transudative (2/8) type profiles. MS-CSF with oligoclonal immunoglobulins on IEF had a higher IgG/Albumin ratio (p = 0.01) than those with polyclonal immunoglobulins, while the mean IgG levels were not significantly different (p = 0.07). These results support the diagnostic usefulness of the IgG/Albumin ratio. Agarose IEF appears to be a useful technic in the detection of oligoclonal immunoglobulins and may be applied at least to CSF of patients with clinical signs of multiple sclerosis.
The Coomassie blue method of proteins quantitation initially reported by Bradford and modified by Macart et al. appears to be simple, fast, sensitive and of low cost. In this study, we report an improved micromethod derived from the technic described by Macart. Applied to the protein quantitation of 100 cerebrospinal fluid (CSF) specimens and 50 serum specimens our method showed a very good correlation with the macromethod of Macart (r = 0.985 for CSF proteins, r = 0.944 for serum proteins) and also with the Lowry technic (r = 0.986 for CSF proteins, r = 0.898 for serum proteins). Our technic may be used with various biological fluids (urines, tears, saliva...) and seems to be of particular interest for low protein level fluids and for little volume samples (it needs only 20 mcl).
Based on previous data on free immunoglobulin light chains in the cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS), we evaluated free kappa and lambda light chains in the CSF from 3 patients groups: (a) 42 with MS, (b) 16 with other neurological inflammatory diseases (ONID) and (c) 42 with non inflammatory neurological diseases (NIND) used as control. The kappa and lambda light chains contents were evaluated using a specific and sensitive (0.5 mcg/ml) enzyme linked immunosorbent assay (ELISA). Whole CSF immunoglobulins G (CSF-IgG) concentrations were determined by an immuno-nephelometric method and CSF oligoclonal banding was assessed by agarose gel electrophoresis. Elevated free kappa light chains levels were found in 36 of the 42 (85.7%) MS-CSF, and only in 2 of the 16 (12.5%) ONID-CSF. Moreover, all MS-CSF with oligoclonal banding (21/42) exhibited detectable free kappa light chains. In contrast, elevated free lambda light chains or whole CSF-IgG concentrations were found not so specific. These results suggest that free kappa light chains measurement in MS-CSF may have an important diagnostic usefulness. This assay offers a reliable alternative to other available procedures and may constitute complementary technique in routine investigation of MS-CSF.
Inhibition of the cyclical contractions of the reticulum and the rumen by detomidine (10-40 micrograms/kg, i.v.), xylazine (20-80 micrograms/kg, i.v.) and clonidine (2.5-10 micrograms/kg, i.v.) were compared in sheep and cattle housed individually in box stalls. Two alpha 2-adrenergic receptor blocking agents, tolazoline and yohimbine, were administered intravenously for prevention (0.1-0.4 mg/kg) or reversal (0.4-1.2 mg/kg) of these effects. Continuous recording of the reticuloruminal contractions and measurement of the volume of ruminal gas eliminated through the upper respiratory tract indicated that the three alpha 2-agonists inhibited the primary ruminal contractions associated with the reticular contractions. The occurrence of secondary ruminal contractions was also blocked in sheep, but only suppressed in cattle. The inhibition of reticulo-ruminal contractions was prevented or reversed competitively by the two alpha 2-blocking agents, suggesting an alpha 2-adrenoceptor mediation of the inhibition of cyclical motor activity of the reticulo-rumen. In contrast with tolazoline, yohimbine was unable to alleviate the accumulation of gas resulting from inhibition of the secondary ruminal contractions.
The relationships between forestomach motility and eructation rate were studied in sheep and cattle. Three ewes and 2 heifers were implanted with strain gauges on the reticulo-rumen and fitted with a cannula in the dorsal sac of the rumen. Studies were performed in sheep after induction of hypocalcemia by Na2EDTA infusion and cattle were studied after ruminal distension. Experiments were performed by measuring the rate and volume of eructated ruminal gases, using a technique by which the trachea is transected. The frequency of reticulo-ruminal contractions decreased 40% within 30 minutes of Na2EDTA infusion to the sheep. The volume of eructated gas (for 30-minute periods) decreased from 10.7 L to 5.5 L at the end of the 60-minute infusion period. Pretreatment with ritanserin (0.1 mg/kg, subcutaneously) not only prevented bloating during the ruminal stasis induced by hypocalcemia, but also significantly increased the eructated volume of gas. In cattle, ritanserin given at the same dose level (0.1 mg/kg, subcutaneously) significantly increased the volume of eructated gas after ruminal distension. This study supports the hypothesis that the caudal esophageal sphincter has a role in the rate of ruminal gas eructation and indicates that its relaxation may be due to a 5-hydroxytryptamine antagonist.