Lectin histochemistry on the dorsal epidermis of the Breton dog

Expression of sugar residues and the nature of oligosaccharide linkage during keratinocyte maturation in the epidermis of the Breton dog were studied with the use of lectin histochemistry. Thirteen lectins were used. Labelling was not observed with GSA I-B4, GSA II, UEA-I, and LTA. The cytoplasm of keratinocytes reacted with PNA, HPA, Con A, and WGA from the basal layer to the granular layer. PNA and Con A showed highest reactivity in the granular cell layer. The cell surface showed increased reactivity with PNA, HPA, and WGA with maturation of keratinocytes. KOH-neuraminidase treatment (KOH-Neu) increased PNA and RCA120 staining during keratinocyte differentiation thus indicating an increase in oligosaccharides terminating with sialic acid-Galbeta(1,3)GalNAc and sialic acid-Galbeta(1,4)GlcNAc, respectively. Labelling of the glycocalyx of basal and spinous keratinocytes with SNA and MAA revealed terminal Neu5acalpha(2,6)Gal/GalNAc and Neu5acalpha(2,3)Galbeta(1,4)GlcNAc. KOH-Neu-DBA showed oligosaccharides terminating with sialic acid-GalNAcalpha(1,3)GalNAc in the spinous and granular layers. A selective glycocalyx labelling of granular keratinocytes was observed with DBA and SBA. Reactions with MAA, PNA, DBA, RCA120, SBA, HPA, and WGA disappeared after the beta-elimination reaction. Our findings indicate that Breton dog epidermis contains more O-linked than N-linked oligosaccharides and confirm that different subpopulations of keratinocytes can be distinguished by lectin histochemistry.     

Interaction between a peroxisome proliferator-activated receptor gamma gene polymorphism and dietary fat intake in relation to body mass

The peroxisome proliferator-activated receptor gamma (PPAR gamma) is a critical regulator of adipogenesis. PPAR gamma+/- mice are resistant to high-fat diet-induced obesity and thus PPAR gamma may mediate physiological responses to dietary fat in other mammals. The aim of this study was to determine whether the human PPAR gamma proline to alanine substitution polymorphism (Pro12Ala) modifies the association between dietary fat and adiposity and plasma lipids. Subjects (n=2141) were controls selected for three case-control studies nested within the Nurses' Health Study, a large ongoing prospective cohort study. Associations between intake of total fat, fat subtypes and BMI were different in PPAR gamma 12Ala variant allele-carriers compared with non-carriers. Among homozygous wild-type Pro/Pro individuals, those in the highest quintile of total fat intake, had significantly higher mean body mass index (BMI) compared with those in the lowest quintile (27.3 versus 25.4 kg/m2, respectively; P-trend<0.0001) whereas among 12Ala variant allele-carriers there was no significant trend observed between dietary fat intake and BMI (P-trend=0.99; P-interaction=0.003). In contrast, intake of monounsaturated fat was not associated with BMI among homozygous wild-type women but was inversely associated with BMI among 12Ala variant allele-carriers (mean in lowest quintile=27.6 versus mean in highest quintile=25.5 kg/m2; P-trend=0.006; P-interaction=0.003). The relationship between dietary fat intake and plasma lipid concentrations also differed according to PPAR gamma genotype. These data suggest that PPAR gamma genotype is an important factor in physiological responses to dietary fat in humans.     

Clinical,immunological, and molecular analysis in a large cohort of patients with X-linked agammaglobulinemia: an Italian multicenter study

A questionnaire-based retrospective clinical and immunological survey was conducted in 73 males with a definite diagnosis of X-linked agammaglobulinemia based on BTK sequence analysis. Forty-four were sporadic and 29 familial cases. At December 2000, the patients' ages ranged from 2 to 33 years; mean age at diagnosis and mean duration of follow-up were 3.5 and 10 years respectively. After the mid-1980s all but 2 were on intravenous immunoglobulin (IVIG) substitution therapy, with residual IgG >500 mg/dl in 94% of the patients at the time of enrollment. Respiratory infections were the most frequent manifestation both prior to diagnosis and over follow-up. Chronic lung disease (CLD) was present in 24 patients, in 15 already at diagnosis and in 9 more by 2000. The cumulative risk to present at diagnosis with CLD increased from 0.17 to 0.40 and 0.78 when the diagnosis was made at the ages of 5, 10, and 15 years respectively. For the 9 patients who developed CLD during follow-up, the duration of follow-up, rather than age at diagnosis; previous administration of intramuscular immunoglobulin; and residual IgG levels had a significant effect on the development of CLD. Chronic sinusitis was present in 35 patients (48%), in 15 already at diagnosis and in 20 by 2000. Sistemic infections such as sepsis and meningitis/meningoencephalitis decreased over follow-up, probably due to optimal protection provided by high circulating IgG levels reached with IVIG.     

Assay method for the perfluorooctyl bromide (perflubron) in rat blood by gas chromatography-mass spectrometry

This paper describes a GC-MS method (SIM mode) for the analysis of perfluorooctyl bromide (perflubron, I) in rat blood. The chromatographic separation was performed by injection in the split mode using a CP-select 624 CB capillary column. Following destruction of the emulsion by addition of ethanol, the analytical procedure involves a liquid-liquid extraction with 1,1,2-trichlorotrifluoroethane. The bis(F-butyl)ethene (II) was used as internal standard. Observed retention times were 3.22 min for I and 2.32 min for II. Two calibration curves were used; linear detection responses were obtained for concentrations ranging from 0.009 to 0.9 mg/ml and from 0.9 to 13.5 mg/ml. The extraction efficiency averaged 50% for I and 93% for II. Precision ranged from 0.7 to 14%, and accuracy was between 91 and 109%. The limit of quantification was 9 microg/ml. The method validation results indicate that the performance characteristics of the method fulfilled the requirements for assay method for use in pharmacokinetic studies.     

Fertility in myotonic dystrophy in Saguenay-Lac-St-Jean: a historical perspective

Myotonic dystrophy (MD) is an autosomal dominant disorder that has a high prevalence in Saguenay-Lac-St-Jean. A case-control study, based on a population register, of 373 MD patients who married in this region between 1855 and 1971 was conducted to determine whether their fertility was affected by the disorder. Six demographic parameters, that is the number of children, the age at marriage, the ages at the time of birth of the first and the last child, the interval between the marriage and the birth of the first child, and the interval between consecutive births, were analyzed. The mean number of children born to MD and control individuals was not different (P > 0.05). However, MD males had more children than MD females although they have started delaying their marriage since 1921. Fertility fell significantly in both the MD and control groups during the period of observation. This change reflects the decline in fertility of French Canadians in general during this period, but mainly after 1940.     

B lymphocyte differentiation in the rat: production and characterization of monoclonal antibodies to B lineage-associated antigens

Three mouse monoclonal antibodies (mAb) directed against rat B lineage antigens were produced. The mAb, designated HIS14 (IgG1), HIS22 (IgM) and HIS24 (IgG2b), were characterized for binding to lymphoid and nonlymphoid tissues by immunoperoxidase staining of frozen sections and by (double-) immunofluorescence staining of single cell suspensions from lymphoid organs. HIS14 recognized a pan B cell determinant: it reacted with virtually all cells of each anatomic B cell compartment and with about 95% of surface (s)Ig+ cells in thoracic duct lymph and in suspensions of spleen and lymph nodes. HIS22 and HIS24 detected B lineage-associated antigens expressed by major subpopulations of B cells. HIS22 predominantly stained the lymphocyte corona, but not (or weakly) the germinal centers and splenic marginal zones, whereas HIS24 reacted with both corona and germinal center and not (or weakly) with marginal zone. In accordance with this, substantial proportions of sIg+ cells in spleen cell suspensions did not express HIS22 or HIS24 determinants (20% and 27%, respectively). In bone marrow the vast majority of cytomplasmic mu+ pre-B cells were HIS14+ and HIS24+, and up to one third also HIS22+, indicating an appearance of the determinants early in B lymphocytopoiesis. The antigens recognized by HIS14, HIS22 and HIS24 are lost during the final stage of B cell differentiation: none of the mAb bound to plasma cells. As far as detectable, neither cells of myeloid and erythroid lineages in bone marrow nor thymocytes were stained by HIS14, HIS22, or HIS24. In suspensions of peripheral lymphoid organs (spleen and lymph nodes) but not in thoracic duct lymph, HIS14 and HIS24 labeled a small proportion (12% and 14%, respectively) of Ig- cells. HIS22 did not bind to Ig- peripheral lymphocytes. Reactivity of HIS14, HIS22 and HIS24 with nonlymphoid tissues was virtually absent; HIS22 stained the high endothelial venules in lymph nodes and Peyer's patches. As determined by immunoblotting, the antigenic determinants on lymph node cells recognized by HIS14, HIS22 and HIS24 were present on molecules with an apparent molecular mass of 205 kDa, 210 (and 175) kDa and 205 kDa, respectively, which is similar to the molecular mass of the B cell form of the rat leukocyte common antigen. In addition, the antigens recognized by HIS14, HIS22 and HIS24 co-capped with the leukocyte common antigen. This suggests that each of the three mAb recognize determinants present on the B cell form of the leukocyte common antigen.     

镁对在体兔缺血—再灌心脏的电生理效应

本实验通过结扎兔冠状动脉左室支复制动脉缺血－再灌注模型，应用心外膜接触电极记录单相动作电位，观察后除极电位在再灌注性心律失常中及镁离子的拮抗作用。结果表明，再灌性心律失常的５２．６％与早期后去极化有关。硫酸镁可终止及预防ＲＡ，对再灌中出现触发活动有抑制作用。     

Amino acid release from the cerebral cortex of the rabbit, its relationship with the electrocorticogram

The rate of release of five amino acids (alanine, glutamine, glutamic acid, glycine, GABA) from the surface of the sensorimotor cortex has been determined in rabbits under local anesthesia immobilized with gallamine. Concomitant recording of the electroencephalogram and of blood pressure has been carried out. The scope of the research was to determine if a difference in the release of these aminoacids could be correlated with variations in cerebral electrical activity. Two open-ended silver cylinders were adapted to the cortex and filled with saline. Every 10 min, the liquid was removed and assayed using a dansylating procedure followed by thin layer chromatographic separation and fluorimetric determination of the amino acids. The EEG of non treated animals, followed for a period of 100 min, remained synchronized for the majority of the recording; the biochemical determinations indicated a slight but constant fall in the rate of release of all the amino acids. A significant increase in the release accompanied the EEG desynchronisation induced either with eserine (0.2 mg/kg), amphetamine (2 mg/kg), or with electrical stimulation of the reticular formation.