Sentinel surveillance on poliomyelitis and neonatal tetanus: a report

A 5 year sentinel surveillance (1989-93) of paralytic poliomyelitis and neonatal tetanus was undertaken at a rural Medical College Hospital at Burdwan, West Bengal. Poliomyelitis incidence showed an overall declining trend, which corroborated with the increased OPV coverage over the years. Incidence was more in males than females. Male:female ratio varied between 2.31:1 to 1.2:1. From 1989 to 1992, age-shift in poliomyelitis was observed when more cases were occurring above 1 year subjects. Cases were reported to be high during the months June to September every year. Incidence of neonatal tetanus (NNT) also showed a declining trend during the 5 year study period. A male preponderance was observed. NNT cases were more prevalent during the months between August and November. In an attempt for eradication of paralytic poliomyelitis and elimination of NNT, containment and other public health measures were undertaken a part of surveillance activities. The obstacles encountered in the surveillance system, as well as lacunae identified in undertaking appropriate health measures was discussed.

Genetic uncoupling of the dsRNA-binding and RNA cleavage activities of the Escherichia coli endoribonuclease RNase III--the effect of dsRNA binding on gene expression

RNase III, a double-stranded RNA-specific endonuclease, is proposed to be one of Escherichia coli's global regulators because of its ability to affect the expression of a large number of unrelated genes by influencing post-transcriptional control of mRNA stability or mRNA translational efficiency. Here, we describe the phenotypes of bacteria carrying point mutations in rnc, the gene encoding RNase III. The substrate recognition and RNA-processing properties of mutant proteins were analysed in vivo by measuring expression from known RNase III-modulated genes and in vitro from the proteins' binding and cleavage activities on known double-stranded RNA substrates. Our results show that although the point mutation rnc70 exhibited all the usual rnc null-like phenotypes, unlike other mutations, it was dominant over the wild-type allele. Multicopy expression of rnc70 could suppress a lethal phenotype of the wild-type rnc allele in a certain genetic background; it could also inhibit the RNase III-mediated activation of lambdaN gene translation by competing for the RNA-binding site of the wild-type endonuclease. The mutant protein failed to cleave the standard RNase III substrates in vitro but exhibited an affinity for double-stranded RNA when passed through poly(rI):poly(rC) columns. Filter binding and gel-shift assays with purified Rnc70 showed that the mutant protein binds to known RNase III mRNA substrates in a site-specific manner. In vitro processing reactions with purified enzyme and labelled RNA showed that the in vivo dominant effect of the mutant enzyme over the wild-type was not necessarily caused by formation of mixed dimers. Thus, the rnc70 mutation generates a mutant RNase III with impaired endonucleolytic activity but without blocking its ability to recognize and bind double-stranded RNA substrates.

Experience in running a Diarrhoeal Training cum Treatment Unit (DTTU) in a state teaching hospital in Calcutta

The performance of the Diarrhoeal Training cum Treatment Unit (DTTU) of NRS Medical College and Hospital, Calcutta, in a 2-year period was evaluated by record analysis. The study revealed that 73.6% cases out of a total 4349 could be successfully managed at the oral rehydration therapy (ORT) area and only 16.5% cases required indoor admission. Rest of the cases (9.9%) with "no dehydration" were sent home with advice. There were 84.7% cases out 3919 dehydration cases who could be successfully treated by ORT and only 15.3% required intravenous (i.v.) therapy. A definite decline was also evident in the proportion of diarrhoea cases requiring antibiotic therapy (13.5% in 1991 to 6.8% in 1992). The case fatality rate due to diarrhoea was 1.7% in 1992. Had all cases of diarrhoea with dehydration being admitted and treated with i.v. fluids and antibiotics, the estimated cost would have been Rs 14.2 lakhs, which with ORT, actually cost Rs 2.4 lakhs. Thus estimated total cost reduction was to the extent of Rs 11.8 lakhs in a 2-year period.

Cell cycle arrest in Era GTPase mutants: a potential growth rate-regulated checkpoint in Escherichia coli

Era is a low-molecular-weight GTPase essential for Escherichia coli viability. The gene encoding Era is found in the rnc operon, and the synthesis of both RNase III and Era increases with growth rate. Mutants that are partially defective in Era GTPase activity or that are reduced in the synthesis of wild-type Era become arrested in the cell cycle at the predivisional two-cell stage. The partially defective Era GTPase mutation (era1) suppresses several temperature-sensitive lethal alleles that affect chromosome replication and chromosome partitioning but not cell division. Our results suggest that Era plays an important role in cell cycle progression at a specific point in the cycle, after chromosome partitioning but before cytokinesis. Possible functions for Era in cell cycle progression and the initiation of cell division are discussed.

Physiological, biochemical and histological changes due to physostigmine in monkeys

Physostigmine (Phy), a short-acting reversible anticholinesterase agent is considered to be a potent prophylactic antidote for the highly toxic organophosphorous (OP) compounds. The toxic effects, if any, of the probable prophylactic doses of Phy have been evaluated by studying its physiological, biochemical and histological effects in monkeys. Phy only at 100 micrograms/kg resulted in certain cholinergic signs such as salivation, lacrymation and muscular faciculations; physiological changes such as mild tachycardia, tachypnea, higher amplitude in electrical activity of the brain, clinico-chemical effects like fall in PO2, PCO2 and alkalosis and histologically an inflammatory reaction in the lungs. On the other hand, the lower dose, i.e. 50 micrograms/kg appeared to be devoid of cholinergic signs and symptoms. However, we observed a significant inhibition of both plasma and erythrocyte ChE and increase in the rectal temperature in both the Phy treated groups. From this study, Phy at a dose of 50 micrograms/kg could be inferred as a safe, sign free intramuscular dose and may probably be used in pretreatment regimen against nerve agents.

Alteration of testicular biochemistry during protein restriction in nickel treated rats

Nickel sulfate (2.0 mg/100 g.b.wt) dissolved in double-distilled water was administered (i.p.) on alternate days for ten doses to normal protein-fed and protein-restricted Wister strain albino rats (b.wt. 160 +/- 5 g). Two groups were used: one with normal protein diet, whereas the other with protein-restricted diet served as control. Twenty-four hours after the last treatment, the animals were sacrificed by decapitation. Tissues such as the testes, seminal vesicles, epididymis (Cauda and Caput) and prostate were dissected out, wiped clean, and stored at -20 degrees C until analysis. Lactate dehydrogenase (LDH) activities, glutamate oxaloacetate transaminase (GOT) activities, glycogen content, cholesterol content, and total protein content of the testes were estimated. Nickel sulfate administration significantly decreased the body weight of both normal protein-fed and protein-restricted groups of animals; the organ weights were also decreased. Significant decrease of LDH activity was observed, but GOT activity was not altered significantly. Testicular glycogen and cholesterol increased significantly in both experimental groups, but total protein content decreased. Nickel sulfate seems to have an adverse effect on the male reproductive system in both groups of animals fed with normal protein (18% casein) diet and protein restricted (5% casein) diet.

Influence of ascorbic acid on acid and alkaline phosphatase activities in some metabolically active tissues of aspirin treated rats

ACP and ALP activities in plasma were increased in aspirin treated groups for a period of seven days. Ascorbic acid supplemented groups showed no significant change in plasma ACP activity, but a significant change in ALP activity was found. ACP and ALP activities in liver and kidney were decreased significantly in aspirin treated animals. ACP activities in liver and kidney in ascorbic acid supplemented groups showed no significant changes. No significant alteration of ALP activity in liver was found in ascorbic acid supplemented group but a significant changes was observed in kidney. Supplementation of ascorbic acid in high doses to rats fed aspirin can restore enzyme activities almost to the normal level.

L-myo-lnositol 1-Phosphate Synthase from Plant Sources (Characteristics of the Chloroplastic and Cytosolic Enzymes)

L-myo-inositol 1-phosphate synthase (EC 5.5.1.4) from cyanobacterial (Spirulina platensis), algal (Euglena gracilis), and higher plant (Oryza sativa, Vigna radiata) sources was purified to electrophoretic homogeneity, biochemically characterized, and compared. Both chloroplastic and cytosolic forms of the enzyme were detected in E. gracilis, O. sativa, and V. radiata, whereas only the cytosolic form was detected in streptomycin-bleached or chloroplastic mutants of E. gracilis and in S. platensis. Both the chloroplastic and cytosolic forms from different sources could be purified following the same three-step chromatographic protocol. L-myo-inositol 1-phosphate synthases purified from these different sources do not differ significantly with respect to biochemical and kinetic parameters except for the molecular mass of the chloroplastic and cytosolic native holoenzymes, which appear to be homotetrameric and homotrimeric associations of their constituent subunits, respectively. Monovalent and divalent cations, sugar alcohols, and sugar phosphates are inhibitory to the enzyme activity. N-ethylmaleimide inhibition of synthase activity could be protected by the combined presence of the substrate glucose-6-phosphate and cofactor NAD+. Antibody raised against the cytosolic enzyme from E. gracilis immunoprecipitates and cross-reacts with both chloroplastic and cytosolic forms from the other sources studied.

A modification of split-skin graft

A modification of the conventional split-skin graft is presented. This modification provides a gain in the length of the donor skin up to a maximum of 1:1.92. The gain in length is achieved in a very short period during an emergency operation. No special instrument is required. This technique has been proved to be useful in burn cases having much less donor site than recipient area. Earlier recovery, shortened hospital stay, earlier rehabilitation, less scar contracture and less morbidity could be achieved with this type of simple modification of a sheet graft.

A comparative study of silver binding nucleolar organiser regions (AgNORs) of breast lesions in histological sections and fine needle aspiration smears

The study presents a comparative profile of AgNOR dot counting in different types of breast lesions in histopathological (HP) sections and fine needle aspiration cytology (FNAC) smears. The breast lesions chosen were non-neoplastic lesion like fibroadenosis, benign neoplastic lesion like fibroadenoma and malignant neoplastic lesion like infiltrating duct carcinoma-grade 2. The AgNOR counts of non-neoplastic lesion were significantly less in number than the neoplastic lesions--both benign and malignant, in both the HP section and FNAC smear. But the counts did not show significant difference in the two neoplastic lesions eg, fibroadenoma and infiltrating duct carcinoma-grade 2, in both the HP section and FNAC smear. The appearance of the dots, as felt by the observers, were more discriminating between the three lesions, eg, uniform small compact centrally placed in fibroadenosis; mostly uniform small compact but occasional large irregular in fibroadenoma and large irregular marginally located in infiltrating duct carcinoma. Counting was easier and the appearance of the dots more easily discernible in FNAC smear than the HP section as the smear was monolayer and the malignant cells were easily detected from macrophages and stromal cells. But the tissue fluid or secretions or blood when present in the smear gave the smear a dirty background which was disturbing to the observers. Thus this AgNOR technique, when applied in HP section or FNAC smear, appears cost ineffective, lengthy and tedious procedure; did not offer absolute histochemical discriminant for malignancy from benignancy. But the shape and size distribution and appearance of the dots showing much variability in FNAC smear than the HP section, might be of some help in the diagnosis of malignancy and discriminating from benignancy.

Anti-steroidogenic activity of the petroleum ether extract and fraction 5 (fatty acids) of carrot (Daucus carota L.) seeds in mouse ovary

The petroleum ether extract and fraction 5 (fatty acids) of carrot seeds arrested the normal estrus cycle of adult mouse and reduced the weight of ovaries significantly. The cholesterol and ascorbic acid content in ovaries were significantly elevated due to the treatment with extract and fraction 5 (fatty acids) of carrot seeds. The significant inhibition of delta 5,3-beta-hydroxy steroid dehydrogenase and glucose-6-phosphate dehydrogenase, the two key enzymes involved in ovarian steroidogenesis, were also observed in mouse ovaries after 15 days of treatment. Results of this study revealed that the fraction 5 (fatty acids) present in carrot seeds acts as an antisteroidogenic agent.

Extent and nature of contacts between protein molecules in crystal lattices and between subunits of protein oligomers

A survey was compiled of several characteristics of the intersubunit contacts in 58 oligomeric proteins, and of the intermolecular contracts in the lattice for 223 protein crystal structures. The total number of atoms in contact and the secondary structure elements involved are similar in the two types of interfaces. Crystal contact patches are frequently smaller than patches involved in oligomer interfaces. Crystal contacts result from more numerous interactions by polar residues, compared with a tendency toward nonpolar amino acids at oligomer interfaces. Arginine is the only amino acid prominent in both types of interfaces. Potentials of mean force for residue-residue contacts at both crystal and oligomer interfaces were derived from comparison of the number of observed residue-residue interactions with the number expected by mass action. They show that hydrophobic interactions at oligomer interfaces favor aromatic amino acids and methionine over aliphatic amino acids; and that crystal contacts form in such a way as to avoid inclusion of hydrophobic interactions. They also suggest that complex salt bridges with certain amino acid compositions might be important in oligomer formation. For a protein that is recalcitrant to crystallization, substitution of lysine residues with arginine or glutamine is a recommended strategy.

Study of myopathies by histological and histochemical methods with special reference to staining for desmin expression

An attempt was made to study the histological and histochemical changes as well as immunohistochemical changes in desmin expression occurring in four types of clinical myopathies e.g. Chronic ischaemic myopathy due to Buerger's disease (Group I), Carcinomatous myopathy (Group II), Metabolic myopathy (Group III) and Muscular dystrophy (Group IV). The number of cases studied were 16 cases, 15 cases, 4 cases and 5 cases respectively. The study revealed: (i) a combination of normal, degenerated, necrotic and regenerating fibres in different proportions in all the four groups having maximum number of degenerated fibres in Group I and Group IV, relatively more number of regenerating fibres in groups III and absence of necrotic fibres in Group I. (ii) Altered tinctorial property in most of the fibres indicating degenerated and regenerating fibres in all the groups with Masson's trichrome staining against inconstant staining with PTAH appear to be a good indicator for myopathy. (iii) The Desmin expression was week and irregular in most of the cases with most of the fibres probably due to reduction of desmin content probably indicating degenerated fibres, appear to be a good indicator for myopathy. (iv) Chronic ischaemic myopathy showed close resemblance with muscular dystrophy though no typical or distinct distinguishing feature could be identified in these four groups.

A study on profile of stillbirths

The incidence of stillbirths in "one year period" was studied by record analysis in a teaching hospital. A stillbirth rate of 38.4 per 1000 live births was observed. On admission 96.3% cases had some adverse foetal conditions detected readily. Leading factor detected was intra-uterine growth retardation (45.4%). Other major conditions observed were intra-uterine hypoxia (18.4%), malpresentation (11.9%), multiple pregnancy (8.3%). Birth weight was below 2000 g in 53.1% cases. Records showed 78.5% mothers had not received antenatal care.

A study of perinatal mortality and associated maternal profile in a medical college hospital

Study of perinatal mortality in a Medical College Hospital revealed stillbirth rate as 38.4, early neonatal death rate as 29.3 and overall perinatal morality rate as 67.7 per 1000 live births. More than half (53.6%) of the perinatal deaths were in primipara and another 22.8% in mothers of parity more than 3. Most mothers (85.9%) did not receive adequate antenatal care services. On admission 35.1% mothers presented with some risk factors. The major risk factors identified were toxaemia of pregnancy (14.8%), severe anaemia (13%) and antepartum haemorrhage (2.6%).

Developmental and topographic expression of neutral glycosphingolipids in vertebrate brain

We have examined neutral glycosphingolipid (Ngsl) expression in embryonic (E), post-natal (P) and adult rodent brain employing digoxigenin immunostaining (DIG-IS) and anti-Ngsl antisera (both monospecific polyclonal and monoclonal) directed toward specific carbohydrates. Several previously unknown long-chain (-CHO = or > 4) Ngsls have been identified. Four Ngsls have been purified and characterized as GgOse4Cer or GA1, Galactosyl beta 1-3globoside, Fuc alpha 1-3nLcOse4Cer or Lewis X (Le(x)) and a novel GalNAc beta 1-4GA1. A few transient bands appear at different developmental ages. Several fast migrating cerebrosides have also been identified during the early phase of active myelination and tentatively characterized as derivatives of galactosylceramide. Immunohistochemical localization of GA1, Le(x) and GalNAc-GA1 in adult rodent brain shows unique and specific cellular topographies of these carbohydrate antigens.

Conformational changes in plant Ins(1,4,5)P3 receptor on interaction with different myo-inositol trisphosphates and its effect on Ca2+ release from microsomal fraction and liposomes

The interaction of the only reported plant inositol trisphosphate receptor with different myo-inositol trisphosphates (InsP3 species), namely Ins(1,4,5)P3, Ins(1,3,4)P3, Ins(1,5,6)P3, and Ins(2,4,5)P3, were studied to assess the extent of Ca2+ mobilization from microsomes/vacuoles as well as liposomes in vitro. Ins(1,4,5)P3 and Ins(2,4,5)P3 bind with the receptor with comparable affinities, as evidenced from their dissociation constants (Kd approx. 100 nM at 5 degrees C), whereas the interaction between Ins(1,3,4)P3/Ins(1,5,6)P3 and the receptor was not detected even with these ligands at 5 microM. Ins(1,3,4)P3/Ins(1,5,6)P3 isomers also do not elicit Ca2+ release from liposomes or microsomes/ vacuoles. The ability of any InsP3 to bind the receptor for Ins(1,4,5)P3 is a prime requirement for Ca2+ release. However, the comparison of binding affinities at a single temperature does not help to correlate it directly with the extent of Ca2+ release from the intracellular stores because the concentration of Ca2+ released by Ins(1,4,5)P3 as estimated over a period of 20 s is 3500 +/- 200 nM/mg of protein and is about 4-fold higher than that by Ins(2,4,5)P3 under identical conditions. To understand the role of the receptor conformation in Ca2+ release by different isomers, we have probed the conformational change of the receptor when the different isomers bind to it. Accessibility of the tryptophan residues in the free and Ins(1,4,5)P3/Ins(2,4,5)P3-bound receptor was monitored by a neutral fluorescence quencher, acrylamide. The resulting Stern-Volmer-type quenching plots of the internal fluorescence indicate a change in the conformation of the receptor on binding to Ins(1,4,5)P3 and Ins(2,4,5)P3. It is also detected when far-UV CD spectra (205-250 nm) of the free and ligand [Ins(1,4,5)P3/Ins(2,4,5)P3]-bound receptor are compared. The results from CD spectroscopic studies further indicate that the conformational changes induced by the two isomers are different in nature. When thermodynamic parameters, such as enthalpy (delta H), entropy (delta S) and free energy (delta G), for the formation of the two InsP3-receptor complexes are compared, a major difference in the extent of changes in enthalpy and entropy is noted. All these findings taken together support the proposition that it is the overall interaction leading to the requisite conformational change in the receptor that determines the potency of the InsP3 isomers in their abilities of Ca2+ mobilization from the intracellular stores or reconstituted liposomes.

Neutral monoglycosylceramides in rat brain: occurrence, molecular expression and developmental variation

Developmental expression of neutral monoglycosylceramides (MGCs) has been examined in rat brain from embryonic day 15 (E15) to postnatal day 30 (P30) and adulthood. To this point, glucosylceramide (GlcCer) is the only MGC that has been characterized in embryonic brain. Galactosylceramide (GalCer) appears at P1, increases with age until P25 and remains constant thereafter. The developmental occurrence of GlcCer and GalCer agrees well with their respective glucosyl- and galactosyltransferase activities. Cerebroside fatty-acid and base compositions, examined by gas chromatography, also change during development. Several alkali-labile fast-migrating cerebrosides (FMCs) with a higher thin-layer chromatography RF than GalCer/ GlcCer are expressed early at P10, increase in concentration with age (P25-P30) and are unchanged until maturity. They are derivatives of GalCer. By employing a newly developed neutral methylation procedure, we have confirmed the structure of one of the FMCs as 6-acylGalCer. A reduction in brain FMC concentrations along with GalCer in murine genetic dysmyelinating disorders (jimpy and quaking) further supports the conclusion that they are myelin constituents.

Adenosine A2A receptors modulate the binding characteristics of dopamine D2 receptors in stably cotransfected fibroblast cells

In membrane preparations from rat striatum, where adenosine A2A and dopamine D2 receptors are coexpressed, stimulation of adenosine A2A receptors was found to decrease the affinity of dopamine D2 receptors for dopamine agonists. We now demonstrate the existence of this antagonistic interaction in a fibroblast cell line (Ltk-) stably transfected with the human dopamine D2 (long-form) receptor and the dog adenosine A2A receptor cDNAs (A2A-D2 cells). In A2A-D2 cells, but not in control cells only containing dopamine D2 receptors (D2 cells), the selective adenosine A2A agonist 2-[p-(2-carboxyethyl)-phenethylamino]-5'-N-ethyl-carboxamido adenosine (CGS 21680) induced a 2-3-fold decrease in the affinity of dopamine D2 receptors for dopamine, as shown in competition experiments with dopamine versus the selective dopamine D2 antagonist [3H]raclopride. By contrast, activation of the constitutively expressed adenosine A2B receptors with 5'-N-ethyl-carboxamidoadenosine (NECA) did not modify dopamine D2 receptor binding. In A2A-D2 cells CGS 21680 failed to induce or induced only a small increase in adenosine-3',5'-cyclic-monophosphate (cAMP) accumulation. In D2 cells NECA- or forskolin-induced adenylyl cyclase activation was not associated with any change in dopamine D2 receptor binding. These results indicate that adenylyl cyclase activation is not involved in the adenosine A2A receptor-mediated modulation of the binding characteristics of the dopamine D2 (long-form) receptor.

Stage-specific expression of fuco-neolacto- (Lewis X) and ganglio-series neutral glycosphingolipids during brain development: characterization of Lewis X and related glycosphingolipids in bovine, human and rat brain

We have purified and characterized a bovine brain pentaglycosylceramide as Lewis X and identified it in human and rat brain using anti-Lewis X (anti-SSEA 1) monoclonal antibody. Neutral glycosphingolipid expression in developing rat brain has been examined by digoxigenin immunostaining and TLC-immunostaining using anti-SSEA 1 and anti-GgOse4Cer (GA1) monoclonal antibodies. Five transient Lewis X-series bands were identified in brain at embryonic day 15 that disappear by postnatal day 5 (one disappears at embryonic day 18). Gangliotetraosylceramide (GA1) first appears at embryonic day 21 and increases in concentration with age until postnatal day 21. In addition, we have purified another minor brain neutral glycosphingolipid and tentatively identified it as a Lewis X-series glycolipid by gas chromatography-mass spectrometry analysis followed by TLC-immunostaining with anti-SSEA 1 antibody.

Regulation of brain m calpain Ca2+ sensitivity by mixtures of membrane lipids: activation at intracellular Ca2+ level

Combinations of certain phospholipids and gangliosides increase the specific activity of m calpain and can activate m calpain at 1 to 10 microM Ca2+ concentration. However, this level of calcium is still greater than the normal intracellular calcium level. We have used combinations of lipids to demonstrate the m calpain activity at the physiological Ca2+ level. GD1a (100 microM) and cerebroside (Cerb; 750 microM; 1:7.5) mixture was the most effective. At 0.5 microM to 1.0 microM Ca2+ concentrations, 15-20% of the maximal activity was detected for the purified myelin and cytosolic m calpains. Other combinations were GD1a (100 microM), GM1 (100 microM), Cerb (750 microM), sulfatide (Sulf; 750 microM), and phosphatidylinositol (PI; 300 microM) at a ratio of 1:1: 7.5:7.5:3, respectively. These lipid mixtures stimulated calpain activity at three- to tenfold less calcium concentration than control. The other mixtures, including GD1a:Sulf (1:9) > GD1a:PI (1:4) > PI:Sulf (1:5) > Cerb:Sulf (1:5) and PI:Cerb (1:2.5), also stimulated calpain activity at 1.0 microM Ca2+ concentration. Triton X-100, oxidized glutathione (GSSG), and calpain activator did not affect the Ca2+ requirement. Liposomes containing GD1a, Cerb, and m calpain also showed recognizable calpain activity at a significantly reduced Ca2+ concentration (0.4 microM), confirming the glycolipid-mediated enzyme modulation. These studies indicate that specific lipid mixtures can stimulate m calpain activity at an intracellular level of Ca2+.

Interaction of myoinositoltrisphosphate-phytase complex with the receptor for intercellular Ca2+ mobilization in plants

One of the myoinositol trisphosphates produced by the phytase-myoinositol hexakisphosphate (InsP6) reaction is Ins(2,4,5)P3. That Ins(2,4,5)P3 can elicit Ca2+ mobilization from intracellular stores in plants [Samanta, S., Dalal, B., Biswas, S., & Biswas, B.B.(1993) Biochem. Biophys. Res. Commun. 191,427] prompted us to elucidate the mechanism. The InsP3 [Ins(1,4,5)P3/Ins(2,4,5)P3]-phytase complex has been found to interact with the receptor for InsP3 in vitro forming a ternary complex, and a nanomolar concentration of InsP3 is required. For enzymatic cleavage of InsP3 by phytase, micromolar concentrations are needed, and the affinities of the phytase for different myoinositol phosphates have been found to depend upon the number of phosphate groups present in the substrate. Fraction accessibility of tryptophan residues to a neutral fluorescence quencher, acrylamide in free and myoinositol phosphates bound phytase, as determined by Stern-Volmer plot, records a progressive decrease starting from InsP6 to InsP with the notable exceptions of both Ins (1,4,5)P3 and Ins(2,4,5)P3. This deviation from the trend of change in the accessibility of tryptophan residues in myoinositol phosphate bound phytase is recorded from the fact that there is a high affinity (dissociation constant of the nanomolar order) and noncatalytic binding site in phytase for the two isomers of InsP3. In the nanomolar range of concentrations, both isomers of InsP3 bind to a second site of phytase having about 40-fold higher affinity than the normal substrate binding site. InsP3, when bound to noncatalytic site in phytase is not hydrolyzed but induces a significant change in the conformation of phytase as assayed from the relative accessibility of tryptophan residues. This conformational change in phytase is recognized by the receptor for InsP3, because in absence of InsP3 no interaction between the receptor and phytase is detected. However, InsP3-phytase complex is a better elicitor of Ca2+ efflux from microsomal/vacuolar fractions than free InsP3. This is further confirmed by the fact that when Ins(1,3,4)P3-phytase complex can elicit Ca2+ efflux from intracellular stores, Ins(1,3,4)P3 per se is minimally effective.

Some host factors and seasonal variations in the fatal road traffic accidents occurring in eastern suburban Calcutta

An extensive study of road traffic accident cases occurring within eastern suburban Calcutta during April 1992 to March 1993 was done. Of which 276 fatal cases having minimum medical aids were taken into consideration to avoid erroneous interpretation. Male pedestrians of age group of 50 years and above were mostly involved during the time period of 5 A.M. to 12 Noon. Fatal Accidents mostly occurred during winter and on the broader roads (Highways) and in majority of cases victims were at fault.

Regulation of dopamine D2 receptor affinity by cholecystokinin octapeptide in fibroblast cells cotransfected with human CCKB and D2L receptor cDNAs

Alteration in dopamine (DA) and/or cholecystokinin (CCK) transmission in the CNS may be of relevance for schizophrenia. Previous findings in striatal membranes give indications of a modulation of DA D2 receptor affinity by CCKB receptor activation. In the present study receptor binding studies were performed in a mouse fibroblast cell line (L-hD2l/CCK), expressing both human D2 receptors (long form, D2L) and human CCKB receptors, and binding sites for [3H]CCK-8S (sulfated CCK octapeptide), the D2 agonist [3H]NPA and the D2 antagonist [3H]raclopride were found and characterized in saturation and competition experiments. 1 nM of CCK-8 caused a significant 38% increase in the KD value of the D2 agonist [3H]NPA binding sites in the L-hD2l/CCK cell membranes. This change was blocked by the CCKB receptor antagonist PD 134308 (50 nM). Furthermore, 1 nM of CCK-8 increased the KD value of the D2 antagonist [3H]raclopride binding sites by 34% (P < 0.05) in the L-hD2l/CCK cell membranes. Control cells (L-hD2l cells) expressing D2L receptors showed no specific [3H]CCK-8S binding sites and no modulation by CCK-8 of the D2L receptors. These findings indicate a modulation of the D2L receptor affinity by activation of the CCKB receptor also when they are coexpressed in a fibroblast cell line. One possible explanation of these data may include a receptor-receptor interaction between the CCKB and D2L receptors.

Fine needle aspiration cytology of ophthalmic lesions

Forty cases of ophthalmic lesions were subjected to fine needle aspiration cytology for pre-operative diagnosis which included retinoblastomas (5 cases), inflammatory and neoplastic lesions of the eyelid and lacrimal glands (29 cases) and extra-ocular orbital lesions (6 cases) inclusive of 3 cases of rhabdomyosarcomas. The lesions were distributed in both the eyes almost in equal proportions. Histological confirmation was obtained in 85% of cases; false positive in only one case with malignant neoplasm of the eyelid and false negative also in only one case with inflammatory pseudotumour which were, histologically, proved to be adenoma of tarsal gland and lymphocytic lymphoma respectively.

Isoform expression of the voltage-dependent calcium channel alpha 1E

The alpha 1E voltage-dependent calcium channel has not been clearly identified with a specific neuronal calcium current. To help identify the role of alpha 1E, we examined differential expression of alpha 1E splice variants in mouse brain and cultured cell lines and examined the gene structure of the region encoding the amino terminal. Three splice variants were analyzed by a ribonuclease protection assay, and a fourth variant reported previously in a fetal human alpha 1E sequence was also detected in mouse brain and a pituitary cell line. Whole brain, telencephalon, and olfactory bulb contained predominantly the splice variant corresponding to alpha 1E-1 although other known variants could be detected. Neuroendocrine cells in vitro (beta TC3 insulinoma cells and AtT-20 pituitary cell lines) expressed predominantly one alpha 1E isoform. The existence of a 5' exon accounting for the origin of variant 5' ends reported in different species was suggested by the sequence of the mouse alpha 1E gene in the region encoding the amino terminal.

Cardiovascular and respiratory changes following exposure to a synthetic toxin of Ptychodiscus brevis

The present study demonstrated cardiorespiratory effects of a synthetic phosphorus-containing ichthyotoxic metabolite elaborated by the marine dinoflagellate Ptychodiscus brevis in anaesthetised cats. The metabolite at a dose of 0.25-1.5 mg/kg i.v., resulted in a dose-dependent fall in blood pressure and such vasodepressor effect was associated with bradycardia. There is initial respiratory apnoea followed by increased rate and depth of respiration (hyperapnoea) following the administration of the toxin. The hypotensive response was accompanied by a decrease in aortic baroreceptor activity. The ECG showed atrioventricular conduction block, arrhythmia and depression of S-T segment and T wave which indicated coronary insufficiency. Vasodepressive property of the toxin is presumably muscarinic in nature as atropine counteracted the vasodepression.

Deduced amino acid sequence of 2S storage protein from Brassica species and their conserved structural features

2S seed storage albumin coding regions from five Brassica species, namely Brassica campestris, B. oleracea, B. nigra, B. juncea, and B. carinata have been cloned by PCR amplification of genomic DNA using oligonucleotide primers and their nucleotide sequences have been determined. These sequences showed more than 85% homology amongst themselves and considerable homology with some other crucifer 2S protein coding sequences. The deduced amino acid sequences showed more homology due to some inconsequential mutations in codons without changing the amino acids. Computer analysis of the protein sequences for possible secondary structure revealed a high degree of conservation of hydrophilic and hydrophobic domains and the invariant positions of cysteine residues. Unrooted phylogenic tree based on the coding region of 2S albumin from different Brassica species cloned by us and published sequences from other Cruciferae indicated that these genes originated before the evolutionary divergence of different Brassica species and were conserved due to some stringent structural and functional features required for seed metabolism.

Additivity and non-additivity between dopamine-, norepinephrine-, carbachol- and GABA-stimulated GTPase activity

The mode of coupling between neurotransmitter receptors and G proteins was investigated by agonist-induced high-affinity GTPase activity in rat striatal membranes. There was a simple additive relationship among dopamine-, carbachol-, and gamma-aminobutyric acid (GABA)-sensitive high-affinity GTPase activity in any combination, indicating that the respective receptors stimulated by these agonists (i.e., dopamine D2, pirenzepine-insensitive muscarinic, and GABAB receptors) interact independently with distinct pools of G proteins. Unexpectedly non-additivity was observed between dopamine- and norepinephrine-stimulation. This lack of additivity was apparently due to stimulation of the same dopamine D2 receptors by both dopamine and norepinephrine, since norepinephrine-stimulated high-affinity GTPase activity could be inhibited by dopaminergic but not adrenergic antagonists. The same non-additivity as seen in rat striatum was confirmed in the membranes prepared from cultured mouse fibroblast cells co-transfected with dopamine D2 and adenosine A2A receptors. The implication of the (non-)additivity between receptor-mediated high-affinity GTPase activity was discussed with a consideration of the possible underlying molecular mechanism.

Determination of brequinar in rat plasma by direct deproteinization and reversed-phase high-performance liquid chromatography with ultraviolet absorbance detection

A direct deproteinization method for the determination of brequinar in rat plasma by high-performance liquid chromatography (HPLC) has been developed. This assay avoids the use of dichloromethane, a known carcinogen, in an existing extraction method. Acetonitrile was used to denature plasma proteins and the supernatant was injected onto the HPLC column. Chromatographic separation of brequinar was conducted on a Biophase octyl column using a mixture of acetonitrile and 0.1 M phosphoric acid (50:50, v/v) as the mobile phase and detection of brequinar was by UV absorbance at 254 nm. The method has been validated in rat plasma over the concentration range of 0.05-50.00 micrograms/ml which is adequate for the determination of pharmacokinetics of brequinar in animals.

Chemical and immunological characterization of galactosyl-beta 1-3-globoside in bovine, human, and rat brain

Our studies of bovine brain neutral glycosphingolipids (Ngsls) have revealed the presence of several short-chain (containing -CHO 1-4) and previously uncharacterized long-chain (-CHO > 4-5) Ngsls. We reported the structural characterization of brain GgOse4Cer (GA1) and have now purified another brain Ngsl to homogeneity. The purified Ngsl migrated close to standard GgOse4Cer and nLcOse5Cer on a TLC plate employing two different solvent systems. The carbohydrate molar composition indicated the presence of Gal/Glc/GalNAc in a ratio of 2.8:1.0:0.9. Five permethylated alditol acetate peaks were characterized as 2,3,4,6-OMe4Gal, 2,4,6-OMe3Gal, 2,3,6-OMe3Gal, 2,3,6-OMe3Glc, and 4,6-OMe2GalNAcMe by gas chromatography-mass spectrometry. The anomeric carbohydrate sequence has been determined by specific exoglycosidase digestion. Six-hundred megahertz 1H NMR spectroscopy of the oligosaccharide released by ceramide glycanase hydrolysis confirmed the structure of the Ngsl as Gal beta 1-3GalNAc beta 1-3Gal alpha 1-4Gal beta 1-4Glc beta 1-1Cer or IV3GalGbOse4Cer. Using the immunooverlay technique with anti-stage-specific embryonic antigen 3 antibody, it was found in bovine, rat, and normal adult human brain and bovine myelin, but not in human or rat myelin.

Waardenburg syndrome with anisocoria and exotropia

A case of Waardenburg syndrome with unusual features such as anisocoria, exotropia is reported.

Reduction of dopamine D2 receptor transduction by activation of adenosine A2a receptors in stably A2a/D2 (long-form) receptor co-transfected mouse fibroblast cell lines: studies on intracellular calcium levels

A stably co-transfected mouse fibroblast cell line, which expresses the long form of the human dopamine D2 receptor and the dog adenosine A2a receptor, was used to analyse the mechanism underlying changes in the cytosolic free calcium concentration ([Ca2+]i) induced by activation of D2 (long-form) receptors and its modulation by the A2a receptor agonist CGS 21680 by means of fura-2 imaging. Quinpirole (1-1000 nM), a D2 receptor agonist, caused a concentration-dependent increase in [Ca2+]i. Haloperidol, a preferential D2 receptor antagonist, completely blocked this [Ca2+]i response to quinpirole. Preincubation with Ca(2+)-free medium containing 2 mM EGTA or a medium containing 320 mM ethanol, an inositol 1,4,5-triphosphate receptor antagonist, substantially diminished the increase in [Ca2+]i evoked by quinpirole. Furthermore, quinpirole totally failed to elevate [Ca2+]i in a medium containing both 2 mM EGTA and 320 mM ethanol. CGS 21680 (1-500 nM) did not, by itself, exert any significant effect on [Ca2+]i. However, 100 nM of CGS 21680 substantially counteracted the [Ca2+]i responses to quinpirole (10-1000 nM). Moreover, this counteraction still occurred after blocking Ca2+ mobilization from intracellular stores with ethanol, but disappeared when the cells were pretreated with the Ca(2+)-free medium containing 2 mM EGTA. Our findings imply that the D2 (long-form) receptors in the present fibroblast cell line can raise [Ca2+]i both via Ca2+ influx from the extracellular medium and Ca2+ release from intracellular stores via activation of inositol 1,4,5-triphosphate receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Fine needle aspiration cytology of bone and joint lesions: an assessment

Fine needle aspiration cytology and subsequent correlation with histology and therapeutic follow-up was done in 198 cases of bone and joint lesions. Overall accuracy was found to be 87.34%; false diagnosis was recorded in 4.5% of cases; 8.08% cases were excluded from correlation as they did not turn up for further treatment or follow-up after the diagnosis. False diagnosis was encountered mostly with inflammatory lesions and primary neoplasms, diagnosing osteosarcoma and Ewing's sarcoma as chronic inflammatory lesion, chondroma as chondrosarcoma and vice versa. The possible cause of default has been discussed. The benign cystic lesions could be diagnosed with almost 100% accuracy by fine needle aspiration cytology where 10% cases were excluded as they could not be followed up.

An assessment of AIDS awareness program--for I.C.D.S. functionaries

An assessment of the "One Day AIDS Awareness Program" for I.C.D.S. functionaries was done. The pre-training knowledge level scores were 55.3%, 39.3% and 60.4% of the total score, in 24-Parganas (S), Burdwan and Calcutta districts respectively. However, the post-training assessment scores were observed to be 91.9%, 84.9% and 94.8% in 24-Parganas (S), Burdwan and Calcutta districts respectively. The percentage increase in mean scores was found to be 66.5%, 115.8% and 57.1% in 24-Parganas (S), Burdwan and Calcutta districts respectively.

Immunoglobulin G subclass-specific antileishmanial antibody responses in Indian kala-azar and post-kala-azar dermal leishmaniasis

Antileishmanial antibody responses in the sera of Indian kala-azar (KA) and post-KA dermal leishmaniasis (PKADL) patients were analyzed by enzyme-linked immunosorbent assay (ELISA) and immunoblot experiments using immunoglobulin G (IgG) class- and subclass-specific reagents. All sera showed antileishmanial reactivities in IgG ELISA which followed the order IgG1 > IgG2 > IgG3, with very little IgG4. Immunoblot analysis with IgG class-specific reagents revealed variable patterns of reactivity by KA and PKADL sera, although certain common bands around the 60- to 63-kDa regions were discernible. Sera from antimony-unresponsive KA cases, on the other hand, strongly recognized two bands at around 20 to 22 kDa, in addition to other bands in the high-molecular-mass region. Further analysis showed that the 28-kDa band was preferentially recognized by the IgG2 isotype, while 20- to 22-kDa and 60- to 63-kDa bands were recognized by the IgG1 isotype. Antibodies belonging to the IgG3 isotype reacted to antigens primarily in the region of 14 to 34 kDa and persisted in patients even several months after cure. Immunoblot studies also revealed the presence of a nonspecific band which arose as a result of binding between a 66-kDa leishmanial antigen and streptavidin. Finally, the results presented in this study suggest that certain leishmanial antigens preferentially stimulate the synthesis of a particular IgG subclass(es), depending on the nature of such antigens or their epitopes.

Study of benign superficial cysts by fine needle aspiration cytology

Fine needle aspiration cytology of 213 cases of different cystic lesions from various regions of body and different superficial organs was analysed in an attempt to present the experience of the authors in the diagnosis of such lesions. The predominant lesion diagnosed by fine needle aspiration cytology was adnexal cyst/sebaceous cyst (41 cases) followed by vascular hamartoma (40 cases) and thyroglossal cyst (9 cases). One hundred fifty-eight (74.2%) out 213 cases were confirmed histopathologically. There was false negative diagnosis in 14 cases (6.6%). The remaining 41 (19.2%) cases did not turn up for further treatment. The fallacies that have been recorded in the diagnosis of thyroid cysts, salivary gland cysts and breast cysts in respect of papillary cystic thyroid carcinoma, muco-epidermoid carcinoma of salivary gland and intraductal carcinoma with fibrocystic disease of breast respectively have been highlighted in the present study.

The role of initial 5-fluorouracil trabeculectomy in primary glaucoma

Sixty-eight patients with primary glaucoma involving 68 eyes were divided into two groups: Group I eyes were subjected to trabeculectomy (n = 38) and Group II eyes underwent trabeculectomy followed by subconjunctival injections of 5-fluorouracil (35 mg) (n = 30). After one year follow-up, Group I eyes exhibited reduction of mean intra-ocular tension from 45.7 mm Hg (pre-operative) to 16 mm Hg; optic disc cupping remained unchanged and 24/38 eyes (63%) were found to have field defects (19/38 i.e. 50% had preoperative field defects.) Group II eyes showed a reduction of mean intra-ocular pressure from 47.3 mmHg to 9.3 mmHg after one year. Mean cup disc ratio was lowered from 0.50:1 to 0.46:1 and 17/30 eyes (57%) which had field defects initially continued to exhibit the same. Complications in Group I and II eyes were shallow anterior chamber [8/38 eyes (21%) from Group I and 8/30 eyes (26%) from Group II], posterior synechiae formation in 10/38 eyes (26%) and 8/30 eyes (26%) and cataract progression in 13/38 eyes (34%) and 12/30 eyes (40%) respectively; only Group II eyes had transient superficial keratitis in 9/30 eyes (30%) and thin blebs in 6/30 eyes (20%). The use of 5-fluorouracil after trabeculectomy for primary glaucoma resulted in lowering of intra-ocular pressure, eliminated the need for antiglaucoma medications post-operatively, reduced the galucomatous cup size, and prevented progression of field loss without having a significantly increased complication rate.

Fallacies of the fine needle aspiration cytology of surgical lesions of liver

Seventy-six cases of surgical hepatomegaly were subjected to fine needle aspiration cytology (FNAC) for initial diagnosis. Primary malignancies, as suspected clinically with adjunction of other investigative procedures, were 29 cases of whom 25 were confirmed by biopsy or therapy. Secondary deposits in liver were 27 of whom 15 were confirmed by therapy. Inflammatory lesions were 9 of whom 6 were confirmed by therapeutic response with specific therapy. Benign lesions were 10 of whom 5 were confirmed by surgery. Diagnosis of malignancies of liver is rather easier than that of benign lesions like hydatid cysts of liver which were Casoni's test negative; and hepatocellular adenoma, as the aspirate in the former is clear fluid and that of the latter is only normal looking liver cells. Thus, in respect of benign lesions of liver, FNAC diagnosis may be clinched after due consideration to the clinical findings, radiological and ultrasonographic findings and ultimately confirmed by exploration. Thus the fallacy lies in aspiration of normal looking liver cells whereby the histology may prove it to be hepatocellular adenoma, well differentiated hepatocellular carcinoma and secondary deposits where the exact site has not been hit. Ultrasonogram (USG) guidance helps in these cases where the same facility is available. This fallacy can again be avoided, where USG guidance is not available, by imparting due importance to clinical findings, USG findings and also by repeat smear.

A revised structure for the disialosyl globo-series gangliosides of human erythrocytes and chicken skeletal muscle

Disialosyl globo-series gangliosides have previously been isolated from chicken skeletal muscle (E. L. Hogan, R. D. Happel, and J.-L. Chien (1982) Adv. Exp. Med. Biol. 152, 273-278; S. Dasgupta, J.-L. Chien, E. L. Hogan, and H. van Halbeek (1991) J. Lipid Res. 32, 499-506) and human erythrocytes (S. K. Kundu, B. E. Samuelsson, I. Pascher, and D. Marcus (1983) J. Biol. Chem. 258, 13857-13866). In both cases, the structure of this ganglioside was proposed to be NeuAc alpha 2-->3(NeuAc alpha 2-->6)Gal beta 1-->3GalNAc beta 1-->3Gal alpha 1-->Gal alpha 1-->4Gal beta 1-->1Cer (V3NeuAcV6NeuAcGb5Cer). We have reinvestigated the human erythrocyte antigen and now propose an alternative structure differing in the location of the NeuAc alpha 2-->6 residue: NeuAc alpha 2-->3Gal beta 1-->3 (NeuAc alpha 2-->6)GalNAc beta 1-->3Gal alpha 1-->4Gal beta 1-->4Glc beta 1-->1 Cer (V3NeuAcIV6NeuAcGb5Cer). This novel structure is supported by results of 1H-NMR spectroscopy, negative ion fast atom bombardment mass spectrometry, and methylation linkage analysis with capillary gas chromatography--mass spectrometry in both electron impact and chemical ionization modes. Furthermore, based on new results from negative ion fast atom bombardment mass spectrometry and linkage analysis, we propose that the chicken skeletal muscle antigen also has this revised structure, differing only in ceramide composition. The terminal tetrasaccharide of these gangliosides is identical to that of GD1 alpha, NeuAc alpha 2-->3Gal beta 1-->3(NeuAc alpha 2-->6)GalNAc beta 1-->4Gal beta 1-->4Glc beta 1-->1 Cer(IV3NeuAcIII6NeuAcGg4Cer), previously identified in a rat ascites hepatoma cell line (T. Taki, Y. Hirabayashi, H. Ishikawa, S. Ando, K. Kon, Y. Tanaka, and M. Matsumoto (1986) J. Biol. Chem. 261, 3075-3078) and a murine lymphoma cell line with low metastatic potential (K. Murayama, S. B. Levery, V. Schirrmacher, and S. Hakomori (1986) Cancer Res. 46, 1395-1402), although they appear to be immunologically distinct.

Branched monosialo gangliosides of the lacto-series isolated from bovine erythrocytes: characterization of a novel ganglioside, NeuGc-isooctaosylceramide

We report the isolation, purification, and structural characterization of three monosialo gangliosides (G-1, G-2, and G-3) from bovine erythrocytes. Each of the purified compounds migrates as a single band on thin-layer chromatography in three solvent systems. All three gangliosides contain ceramide (Cer) as the lipid protein, with d18:1 sphingosine as the predominant long-chain base and with C18:0, C18:1, C20:0, C20:1, and C22:1 fatty acids, as determined by gas chromatography. The structural characterization of the carbohydrate moieties of G-1, G-2, and G-3 involved glycosyl composition analysis, methylation studies, sequential exoglycosidase hydrolysis, and one-dimensional 1H NMR spectroscopy of the native gangliosides. Furthermore, the oligosaccharides were released from the sphingolipids by endoglycoceramidase and fully sequenced by one- and two-dimensional 1H NMR spectroscopy in conjunction with fast-atom-bombardment mass spectrometry and exoglycosidase treatment. The structures are as follows: [formula: see text] Gangliosides such as G-1, G-2, and G-3, with branched oligosaccharide chains comprising a number of N-acetyllactosamine (Gal-GlcNAc) moieties, are abundant in erythrocytes from various mammalian species. The simultaneous occurrence of sialic acid and alpha-galactose as terminal sugars in these gangliosides, however, is relatively rare. Specifically, G-1 represents a ganglioside with a novel structure.

Utilisation of ORT during diarrhoea in three districts of West Bengal

Use of ORT is saving 1 million diarrhoeal deaths each year among children. C.S.S.M. programme aims at preventing 70% diarrhoeal deaths, through widespread use of ORT. The present study was carried out to find out the extent of the problem of diarrhoea and utilisation of ORT in three districts of West Bengal. The results showed that the utilisation of ORT was 80.8%, 70.7% and 65% in Howrah, Hooghly and 24-Parganas (South) respectively, during attacks of diarrhoea. The continuing feeding rates were 60.1%, 62.7% and 55.5% in Howrah, Hooghly and 24-Parganas (South) respectively.

Vaccination with the immediate-early protein ICP47 of herpes simplex virus-type 1 (HSV-1) induces virus-specific lymphoproliferation, but fails to protect against lethal challenge

Assessing the immunobiological function of the individual proteins of herpes simplex virus-type 1 (HSV-1) continues to be important in elucidating virus-host interactions and for the rational design of subunit vaccines. In this report, the non-structural, immediate-early protein ICP47 of HSV-1 was examined for its ability to induce virus-specific immune responses. The ICP47 protein, when expressed from a recombinant vaccinia virus or when produced by cell-free, in vitro translation, induced a vigorous HSV-1-specific lymphoproliferative response. However, other common parameters of immunity such as neutralizing antibody, delayed-type hypersensitivity, and class I major histocompatibility complex (MHC)-restricted cytotoxic T lymphocytes (CTL) were not induced by ICP47. Moreover, mice immunized with vaccinia-expressed ICP47 were unable to survive lethal challenge with virulent HSV, indicating that in spite of its ability to induce significant HSV-1-specific lymphoproliferation, ICP47 appears unable to afford protective immunity in vivo. Possible reasons for this failure and the implications of these results in terms of vaccine design are discussed.

Molecular characterization of gangliotetraosylceramide (GA1) in normal human brain and its developmental change

Several neutral glycosphingolipids have recently been purified from normal human brain to the criterion of migration as homogeneous bands in two different solvent systems. One of these has been permethylated and analyzed by gas chromatography. Stepwise specific exoglycosidase hydrolysis confirms its structure as GAl or Gal beta 1-->3GalNAc beta 1-->4Gal beta 1-->4Glc beta 1-->1Cer. The neutral glycosphingolipids of rat CNS have been examined in order to investigate changes in GA1 during critical ages of brain development. Employing the highly sensitive techniques of digoxigenin (DIG) immunostaining and Fluorescence Assisted Carbohydrate Electrophoresis (FACE), we have identified several previously uncharacterized long chain neutral glycosphingolipids in brain and myelin. A major band with Rf close to that of nLcOse5Cer purified from bovine erythrocytes has been identified as GA1 by immuno-TLC using mono-specific polyclonal anti-GA1 antisera. It appears in 5 day-postpartum (P5) developing brain, increases until 21 days (P21) and subsequently declines. This phasic change along with changes in other nonsialylated glycosphingolipids of the developing brain strongly suggests that GA1 and other neutral glycosphingolipids may play a mediator role(s) in brain development and/or myelinogenesis.