ELAM-1 mediates cell adhesion by recognition of a carbohydrate ligand, sialyl-Lex

Recruitment of neutrophils to sites of inflammation is mediated in part by endothelial leukocyte adhesion molecule-1 (ELAM-1), which is expressed on activated endothelial cells of the blood vessel walls. ELAM-1 is a member of the LEC-CAM or selectin family of adhesion molecules that contain a lectin motif thought to recognize carbohydrate ligands. In this report, cell adhesion by ELAM-1 is shown to be mediated by a carbohydrate ligand, sialyl-Lewis X (SLex; NeuAc alpha 2,3Gal beta 1,4(Fuc alpha 1,3)-GlcNAc-), a terminal structure found on cell-surface glycoprotein and glycolipid carbohydrate groups of neutrophils.

cDNA cloning and immunological characterization of the rye grass allergen Lol p I

The complete amino acid sequence of two "isoallergenic" forms of Lol p I, the major rye grass (Lolium perenne) pollen allergen, was deduced from cDNA sequence analysis. cDNA clones isolated from a Lolium perenne pollen library contained an open reading frame coding for a 240-amino acid protein. Comparison of the nucleotide and deduced amino acid sequence of two of these clones revealed four changes at the amino acid level and numerous nucleotide differences. Both clones contained one possible asparagine-linked glycosylation site. Northern blot analysis shows one RNA species of 1.2 kilobases. Based on the complete amino acid sequence of Lol p I, overlapping peptides covering the entire molecule were synthesized. Utilizing these peptides we have identified a determinant within the Lol p I molecule that is recognized by human leukocyte antigen class II-restricted T cells obtained from persons allergic to rye grass pollen.

Serodiagnosis of leprosy in patients' contacts by enzyme-linked immunosorbent assay

Serum samples from 3336 contacts of leprosy patients were tested for antiphenolic glycolipid I antibodies by enzyme-linked immunosorbent assay with the albumin coupled synthetic disaccharide antigen. The overall positivity rate was 9.3%. No significant differences were seen between a group of household contacts of lepromatous patients and those of the other types of the disease. The proportion of ELISA positives was slightly higher in the relatives as compared to workplace contacts and neighbours but significantly different only between the two former (p less than 0.05). Among those contacts with absorbance values higher than 0.100, 5 new leprosy patients were diagnosed, 2 of them with positive skin smears. A sixth contact was detected with a very high absorbance value in whom no single skin lesion was found but whose lepromin reaction was 0 mm and the skin smear showed a bacteriological index of 3+.

Probability of cardiac disease: Framingham revisited

A study was undertaken to test the utility of a strict Bayesian formulation for the diagnosis of coronary disease. Using known probabilities of the disease for men and women in four different age groups and by estimating the probabilities of disease in patients with four important risk factors, we were able to estimate the probability of coronary disease in 512 different subsets of patients. We found that it was not possible to rigourously apply Bayes formula because neither the probability of the risk factor given the disease nor in patients without disease was obtainable in the medical literature. We conclude that to use Bayes formula without equivocation in coronary diagnosis does not appear possible in the present state of statistical knowledge. Rather, an expert system in the form of a knowledge-base would appear to be more achievable.

Prospective study of diarrheal diseases in Venezuelan children to evaluate the efficacy of rhesus rotavirus vaccine

The efficacy of a rhesus rotavirus vaccine (MMU 18006, serotype 3) against infantile diarrhea was evaluated by active home surveillance of a group of 320 children 1-10 months of age in Caracas, Venezuela. During a 1 year period following oral administration of vaccine or placebo under a double-masked code, over 600 diarrheal episodes were detected. Etiologic studies revealed that heat-stable toxin (ST) producing enterotoxigenic E. coli (ETEC) was the most common diarrheal agent detected (34%) followed by enteropathogenic E. coli (EPEC, 10.9%), heat-labile toxin (LT) producing ETEC (7.6%), rotavirus (6.9%), Cryptosporidium (4.8%) and Campylobacter (1.3%). ST-producing ETEC were also recovered from over 20% of control stool specimens obtained during diarrhea-free periods, whereas EPEC, rotavirus, Cryptosporidium, and Campylobacter were rarely detected in such control specimens. Rotavirus was responsible for about one-half of the more severe cases of diarrhea. Twenty-two of 151 infants who received placebo (14.6%) and eight of 151 receiving a 10(4) PFU dose of vaccine (5.3%) had rotavirus diarrhea during the follow-up period for an efficacy level of 64% against any rotavirus diarrhea. However, vaccine efficacy reached 90% against the more severe cases of rotavirus diarrhea and was noticeably high in the 1-4 month age group. Serotypic analysis of the rotaviruses detected suggests that the resistance induced by the vaccine was type specific since significant protection was only evident against serotype 3 rotaviruses. A 10(3) PFU dose tested initially in 18 children did not appear to protect against rotavirus diarrhea.

Inhibition of autoimmune disease in a murine model of systemic lupus erythematosus induced by exposure to syngeneic photoinactivated lymphocytes

MRL/l mice develop progressive, virulent autoimmune disease that has many of the features of systemic lupus erythematosus. Prophylactic treatment of MRL/l mice with syngeneic photoinactivated autoimmune splenocytes improves survival and inhibits the fulminant hyperproliferation of abnormal T cells and the production of high titer anti-DNA antibody invariably found in untreated mice. The proliferation of Thy 1+ splenic T cells was significantly decreased, and prolonged retention of the response to T-cell mitogen was found in treated mice. Treatment with unmodified cells induced a partial inhibition of disease features which did not prolong survival rates. These results suggest that phototherapy potentiates a normal immunoregulatory process which enables suppression of the development of abnormal cell populations in young MRL/l mice with relatively intact immune systems.

NK sensitivity and lung clearance of MHC-class-I-deficient cells within a heterogeneous fibrosarcoma

The present study examines clonal variations in NK sensitivity in a methylcholanthrene-induced fibrosarcoma. Previous studies of clones from this tumor have shown considerable heterogeneity in H-2 expression, and an association between deleted or low levels of class-I products and increased tumorigenicity after subcutaneous implantation in immunocompetent syngeneic mice. Here, fibrosarcoma clones with no or low expression of MHC-class-I products were found to be sensitive to NK-mediated lysis, while clones with high levels of MHC-class-I expression were relatively resistant. One H-2+ (G2) and one H-2- (B9) clone were chosen for more detailed studies. Cold-target competition assays and conjugate cytotoxicity assays in agarose showed that splenic effector cells bound equally well to the H-2+ and H-2- tumor clone, although only the latter was sensitive to NK cell lysis. Treatment with 50 U/ml of rIFN-gamma for 48 hr increased the levels of H-2 expression and made both clones more resistant to NK-mediated lysis. In vivo studies with radiolabelled tumor cells showed that cells from the H-2+ clone survived better than cells from the H-2- clone in the pulmonary capillary bed after i.v. inoculation. This difference disappeared in mice treated with anti-asialo GM1 serum, known to deplete NK cell activity.

Generation of syngeneic anti-tumour double negative cells (CD4- CD8-), with cytotoxic activity against clones of different MHC class I expression

In vivo immunization and secondary culture techniques were used to generate cytotoxic T lymphocytes against a tumour cell clone obtained from a methylcholantrene-induced fibrosarcoma. Our CTLs differed from classical CTLs (Ly2+ and MHC restricted) in that our lymphocytes exhibited a non-MHC restricted cytotoxic activity directed to the original tumour and to other MCA-induced tumours, but have failed to demonstrate any killing activity against a wide range of tumour cell lines of diverse origin (including NK sensitive targets). Depletion and phenotypic studies demonstrated that these cells bear the Thyl.2 antigen but are negative for both Ly2 and L3T4 antigens. These CTLs may belong to a double negative subset (CD4-, CD8-) involved in the anti-tumour response.

Population pharmacokinetic study of gentamicin and a Bayesian approach in patients with renal impairment

A population pharmacokinetic study was conducted on a total of 70 patients receiving gentamicin therapy. The patients included those with normal renal function and those with varying degrees of renal impairment. The parameters studied were the apparent volume of distribution and the plasma clearance of gentamicin. The interindividual variability and the residual variability of those parameters in the different subpopulations were studied according to a statistical model that assumed log normal distribution. Use of the one-way ANOVA test revealed statistically significant differences (P = 0.004) in the population plasma clearance of gentamicin in patients below and above 50 years of age. A linear relationship was established between the plasma clearance of gentamicin and the creatinine clearance in those patients. At the same time, the coefficient of variation of the Clp increased progressively in patients with renal impairment, varying between 28.98% in patients with a ClCR greater than 100 ml/min and 76.53% in patients with a ClCR between 20 and 60 ml/min. The results obtained in the population study were later applied to drug monitoring in 23 patients with varying degrees of renal function and who received gentamicin therapy with different doses. The residual variability of the population allowed us to calculate a weighting factor (FF) between the experimental and the population data using Bayesian fitting. The weighting factor was 0.89 in patients with normal renal function and 0.80 in patients with renal impairment. Statistical comparison of the pharmacokinetic parameters obtained from the populational data, non-linear regression and the Bayesian method using revealed differences in the values for the apparent volume of distribution obtained with the two methods.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of antiskin allograft immunity by infusions with syngeneic photoinactivated effector lymphocytes

Induction of tolerance for skin allotransplantation requires selective suppression of the host response to foreign histocompatibility antigens. This report describes a new approach that employs pretreatment of effector cells with 8-methoxy-psoralen (8-MOP) and ultraviolet A light (UVA) to render the effector cells of graft rejection immunogenic for the syngeneic recipient. Reinfusion of photodamaged cells resulted in an immunosuppressive host response that permitted prolonged retention of histoincompatible skin grafts and specifically inhibited in vitro and in vivo responses that correlate with allograft rejection. Eight days after BALB/c mice received CBA/j skin grafts, their splenocytes served as a source of alloreactive effector cells. The splenocytes were treated with 100 ng/ml 8-MOP and 1 J/cm2 UVA before reinfusion into naive BALB/c recipients. Recipient mice were tested for tolerance to alloantigens in mixed leukocyte culture (MLC), cytotoxicity (CTL), delayed type hypersensitivity assays (DTH), and challenge with a fresh CBA/j graft. Splenocytes from BALB/c recipients of photoinactivated splenocytes containing the effector cells of CBA/j alloantigen rejection proliferated poorly in MLC and generated lower cytotoxic T cell responses to CBA/j alloantigens in comparison with sensitized and naive controls. Splenocytes from these hyporesponsive mice suppressed the MLC and CTL response to alloantigen from sensitized and naive BALB/c mice. In vivo the DTH response was specifically suppressed to the relevant alloantigen in comparison with controls. Moreover, BALB/c mice treated in this fashion retained a CBA/j skin graft for up to 42 d posttransplantation without visual evidence of rejection. These results indicate that the in vivo and in vitro response to alloantigen can be attenuated by pretreating the host with photoinactivated splenocytes containing the effector cells of alloantigen rejection.

Effect of timing of hepatitis B vaccine doses on response to vaccine in Yucpa Indians

In a large hepatitis B prevention programme, hepatitis B vaccine was given in standard doses to greater than 1000 susceptible Yucpa Indians between 1983 and 1985. Thirteen months after the programme began, 373 vaccine recipients were tested using commercial radioimmunoassay to titre antibody response to the vaccine. Because of logistic difficulties, only 32% had received vaccine by the recommended schedule (second and third doses at one and six months after the first, respectively). The second and third doses were received early by 4 and 31%, respectively, and 27 and 16% received these doses later than intended. Overall response to vaccine was excellent: 98% of vaccinees developed anti-HBs greater than 10 mIU (geometric mean titre 688 mIU). Multivariate analysis showed that the response to vaccination was inversely related to the age of the vaccinee and directly related to the timing of the third vaccine dose. In particular, those receiving the third vaccine dose late (greater than 7 months after the first dose) developed antibody titres two-fold higher than those receiving the third dose on schedule (p less than 0.01). The response to vaccination was not significantly related to the timing of the second dose. A satisfactory response was obtained with various schedules of dose timing, including early second and third doses, late second and third doses and late second but normal third doses. These findings suggest that the response to hepatitis B vaccine is not highly dependent on timing of vaccine doses and that modest alterations in timing of doses, such as those necessary to integrate hepatitis B vaccine with other childhood vaccines, do not affect the excellent response to this vaccine.

Reactions to and antigenicity of two human-rhesus rotavirus reassortant vaccine candidates of serotypes 1 and 2 in Venezuelan infants

The reactions to and antigenicity of two human-rhesus rotavirus (RRV) reassortants (human rotavirus strain D x RRV and human rotavirus strain DS1 x RRV) with the VP7 neutralization specificity of a serotype 1 or serotype 2 rotavirus were evaluated in a placebo-controlled double-blind trial in 116 1- to 5-month-old infants in Caracas, Venezuela. The children were randomly divided into five groups to receive orally the following inocula: (i) 10(4) PFU of D x RRV reassortant; (ii) 10(4) PFU of DS1 x RRV reassortant; (iii) 10(4) PFU of RRV; (iv) 5 x 10(3) PFU of D x RRV and 5 x 10(3) PFU of RRV; and (v) placebo. The children were examined daily for 7 days following vaccine administration; 8 to 26% of the vaccinated infants developed a mild febrile reaction which in most cases lasted only 1 day. Seroresponses to rotavirus were observed in 39 to 65% of the vaccinees by plaque neutralization assay and in 57 to 88% by an immunoglobulin A enzyme-linked immunosorbent assay. Vaccine shedding was detected in 53 to 86% of the vaccinees. Analysis of neutralization antibody responses indicates that the VP4 protein represents an important component of the response induced by the vaccines.

Computer-assisted diagnosis of acute abdominal pain

An acute abdominal pain program run on a microcomputer is described and the experiences tabulated for a series of 194 patients seen in a general hospital setting. The initial diagnostic accuracy of the program compared favorably with that of attending physicians and house staff, and suggests that improvements in the program can lead to a more effective and more accurate abdominal pain program. The possibilities for developing other programs, particularly chest pain, fever, and other global categories, are obvious. We are presently working on a chest pain program and a diagnostic strategy program. Based on the results reported here, we believe that several factors could improve program accuracy. For example, with additional clinical studies and refinement of the program structure, with more expert knowledge, and with further algorithmic development, the program could be made to outperform the average clinician and possibly approach the level of true clinical experts in abdominal pain diagnosis by mimicking their analysis. Indeed, since a program of this type is capable of incorporating the expertise of many different clinicians, it has the potential of outperforming any given expert in specific cases.

Developmental changes in rat hepatic casein kinases 1 and 2

Cytosolic histone kinase and casein kinase activities varied considerably in the late fetal and postnatal periods of liver development. Both activities showed a maximum at day 21 of gestation and decreased at birth to values close to those of adult rats. The changes in total casein kinase activity were due to variations of casein kinase 1 and casein kinase 2. Similarly the activities of both the cyclic-AMP-dependent protein (histone) kinase and the cyclic-AMP-independent histone kinase varied during development. Besides the changes in total activity, the affinity of casein kinases 1 and 2 for casein also varied in fetal and postnatal development. The Km values of casein kinase 2 increased from day 18, reached a maximum at day 20 of gestation and then started to decrease until one day after birth. In contrast the Km values of casein kinase 1 decreased from day 18, reached its lowest value at day 21 of gestation and attained values similar to those in the adult at the day of birth. Changes in this parameter were also observed when insulin (3 IU/kg) was administered by intraperitoneal injection to one-day-old rats. The Km values of casein kinase 1 decreased while those of casein kinase 2 increased after administration of this hormone. On the other hand, the Km values for ATP of casein kinases 1 and 2 as well as their apparent molecular masses and sensitivity to heparin and GTP did not significantly change during ontogeny of rat liver.

Low affinity binding sites for 1,4-dihydropyridines in mitochondria and in guinea pig ventricular membranes

In this paper, we describe the occurrence of both high and low affinity sites for dihydropyridines in crude membrane preparations from guinea pig ventricular tissue. The physiological significance of the low affinity site (apparent dissociation constant = 76 +/- 9 nM) is not currently known; it has, however, a binding capacity which was 300-1000 times that of the high affinity site and was resistant to heat denaturation. The magnitude of the binding to the low affinity site was affected by both the ionic strength of the medium and by the presence of divalent ions. Both unlabeled nitrendipine and nimodipine inhibited [3H]nitrendipine binding at both sites, but verapamil and diltiazem only affected binding at the high affinity site. We also characterized, both kinetically and by equilibrium binding, a low affinity, heat-stable nitrendipine binding site in purified mitochondria. The Bmax for this site was also dependent on ionic strength. This suggests the possibility that the low affinity site in crude membranes is due to mitochondrial contaminants and hence not directly related to voltage-dependent calcium channels.

Toxins that affect voltage-dependent calcium channels

At this time, there are five potential candidates for calcium channel specific toxins. All five of these toxins appear to affect the function of voltage-dependent calcium channels. Atrotoxin, beta-leptinotarsin-h and maitotoxin activate channels, whereas both taicatoxin and omega-conotoxin are inhibitors. Neither maitotoxin nor omega-conotoxin alters the binding of dihydropyridines to membranes derived from the cells upon which the toxins exert their effects. In contrast, both atrotoxin and taicatoxin inhibit the binding of dihydropyridines to ventricular membranes. It is not currently known whether beta-leptinotarsin-h affects the binding. The effects of maitotoxin and atrotoxin are blocked by dihydropyridines and verapamil. Direct binding studies with radiolabeled toxins have been performed only with omega-conotoxin, and the binding site density for this toxin appears to be at least one order of magnitude greater than the density of dihydropyridine binding sites in synaptosomes. Studies to examine the third and fourth criteria which we have listed (i.e. that the effects are not via a second messenger, or an enzyme activity) have not been reported for either beta-leptinotarsin-h or omega-conotoxin. Atrotoxin and taicatoxin, added outside a patch pipette, have no effects on calcium channels within the patch and are, therefore, probably not affecting calcium channels via a second messenger. Maitotoxin, however, affects the formation of inositol phosphates and, hence, could be affecting the channel indirectly. The fractions containing the toxic components atrotoxin and taicatoxin have no phospholipase or protease activity, and this is presumably true also for omega-conotoxin since it has been purified to homogeneity. Although all of the toxins have the potential to be important tools with which to study calcium channel structure and function, a number of experiments remain to be done in order to establish conclusively that these five toxins bind specifically to the voltage-dependent calcium channel. In conclusion, we would like to briefly mention why so much effort is being devoted to the search for these calcium channel specific toxins. Such a toxin would provide a very valuable tool in the study of calcium channels for a number of reasons. First, the toxin would be another ligand for the channel and, as such, would provide an alternative to organic ligands such as the dihydropyridines which are lipophilic and, in many tissues, have more than one binding site.(ABSTRACT TRUNCATED AT 400 WORDS)

Protection against severe rotavirus diarrhoea by rhesus rotavirus vaccine in Venezuelan infants

The efficacy of the rhesus rotavirus vaccine candidate MMU-18006 was evaluated in a longitudinal double-blind field trial in Caracas, Venezuela. 247 infants aged 1-10 months were studied and followed for up to 1 year (201 completed the 1-year surveillance): 123 received a dose of 10(4) plaque-forming units of the vaccine orally and 124 received placebo. 21 episodes of rotavirus diarrhoea were detected, 16 in the controls and 5 in the vaccines: vaccine efficacy against any rotavirus diarrhoea was thus 68%. In the 1-5-month-old group the vaccine efficacy was 93%; only 1 episode of rotavirus diarrhoea was detected in 68 vaccinees and 15 such illnesses were observed in 65 controls (p less than 0.0001). For the entire study group vaccine efficacy was 100% against the most severe rotavirus diarrhoeal episodes.

Topography of glycosylation reactions in the rough endoplasmic reticulum membrane

The translocation of UDP-glucose and GDP-mannose from an external to a luminal compartment has been examined in rat liver vesicles derived from the rough endoplasmic reticulum (RER). RER vesicles with the same topographical orientation as in vivo were incubated with a mixture of [3H]UDP-glucose and UDP-[14C]glucose to demonstrate that the intact sugar nucleotide was translocated into the lumen of the vesicles. The translocation of UDP-glucose was dependent on temperature and was saturable at high concentrations of the sugar nucleotide. The transfer of glucose to endogenous acceptors was dependent on the translocation of UDP-glucose into the lumen of the RER since leaky vesicles resulted in both a decrease in transport and transfer of glucose to endogenous acceptors. Preliminary results suggest that the mechanism of UDP-glucose transport into RER-derived vesicles is via a coupled exchange with luminal UMP. Using the same experimental approach to detect translocation of UDP-glucose into the lumen of RER vesicles, we were unable to detect transport of GDP-mannose. Incubation of leaky vesicles with GDP-mannose resulted in stimulation of the amount of mannose transferred to endogenous acceptors, in marked contrast to that observed for UDP-glucose and UDP-N-acetylglucosamine. These results suggest that whereas UDP-glucose is translocated across the RER membrane in vitro, GDP-mannose is not transported. In addition, these results tentatively suggest that there is asymmetric synthesis of the lipid-linked oligosaccharides within the membrane of the RER.

Anti-SSA(Ro) antibody: a connective tissue disease marker

The characteristics of 100 patients with anti-SSA(Ro) antibody were studied. By accepted criteria 34 patients had systemic lupus erythematosus, 25 had other known connective tissue diseases (CTD) and 9 had no significant evidence of a CTD. Thirty-two patients had an unclassified CTD characterized in most instances by arthritis, dermatitis, and a positive fluorescent antinuclear antibody test. The results support the concept of a continuous spectrum of autoimmune disease in which anti-SSA(Ro) antibody may be a marker and in which a variety of disorders may be found that cannot be classified by accepted criteria.

Genetic relatedness among human rotaviruses

The genetic relatedness of 81 clinical rotavirus isolates to the human rotavirus prototype strains Wa (subgroup 2, serotype 1) and DS-1 (subgroup 1, serotype 2) was examined by RNA hybridization techniques. Labeled single-stranded (+) transcripts of Wa or DS-1 virus were incubated with denatured genomic rotaviral RNAs, and the resulting hybrids were subjected to gel electrophoresis and autoradiography. Nineteen of the specimens contained subgroup 1 rotavirus with a "short" RNA migration pattern. These viruses were found to be closely related to the DS-1 strain and were associated with illness of short duration. The remaining 62 isolates belonged to subgroup 2 and exhibited a "long" RNA migration pattern. Fifty-four of these isolates exhibited significant hybridization with the Wa strain probe. Four isolates yielded multiple hybrid bands with the Wa probe but also possessed at least one gene segment homologous to the DS-1 strain. The remaining four subgroup 2 rotaviruses did not exhibit significant homology in the form of labeled hybrid bands when tested with either the Wa or DS-1 probe. These findings suggest that most clinical rotavirus isolates belong to one of two human rotavirus "families" defined as Wa-like or DS-1-like. Our observations also suggest that reassortment occurs in vivo between rotaviruses belonging to the two human rotavirus "families" and that there are one or more additional families of human rotavirus.

Cryptosporidiosis in Venezuelan children with acute diarrhea

Thirteen of 120 Venezuelan children with acute diarrhea were found to be excreting Cryptosporidium oocysts in their stools. This confirms that Cryptosporidium can infect immunocompetent children, and the relatively high frequency found suggests that this protozoan may be an important cause of diarrhea in Venezuela.

Translocation of UDP-N-acetylglucosamine into vesicles derived from rat liver rough endoplasmic reticulum and Golgi apparatus

A mixture of UDP-N-acetylglucosamine labeled with different radioisotopes in the uridine and glucosamine was used to show that the intact sugar nucleotide was translocated across the membrane of vesicles derived from rat liver rough endoplasmic reticulum (RER) and Golgi apparatus. Translocation was dependent on temperature, saturable at high concentrations of sugar nucleotide, and inhibited by treatment of vesicles with proteases, suggesting protein carrier mediated transport. Translocation of UDP-GlcNAc by RER-derived vesicles appeared to be specific since these vesicles were unable to translocate UDP-galactose, in contrast to those derived from the Golgi apparatus. Preliminary results suggest that the mechanism of UDP-GlcNAc translocation into RER-derived vesicles is via a coupled exchange with lumenal nucleoside monophosphate. This is similar to the recently postulated mechanism for translocation of sugar nucleotides into vesicles derived from the Golgi apparatus.

Leukopenia in Still's disease

Two patients, one a 14-year-old girl and the other a 20-year-old man, with typical manifestations of juvenile rheumatoid arthritis had leukopenia and thrombocytopenia, two heretofore unreported findings. The presence of leukopenia should not be used to exclude a diagnosis of Still's disease.

High out-put congestive heart failure as first manifestation of Osler-Weber-Rendu disease

We present two cases of hemorrhagic hereditary telangiectasia (HHT) or Osler-Weber-Rendu disease which started as heart failure. Both had multiple arteriovenous fistulas, one of them in a rare localization in this disease, a lower extremity. We conclude stressing the importance of thinking of HHT in the presence of obscure heart failure or arteriovenous fistulas and of looking for internal fistulas when faced by a HHT.

Relative frequency of rotavirus subgroups 1 and 2 in Venezuelan children with gastroenteritis as assayed with monoclonal antibodies

Monoclonal antibodies recently developed against the 42,000-dalton protein of two rotavirus strains were used in an enzyme-linked immunosorbent assay to determine the subgroup specificity of 252 specimens collected during a 45-month period from Venezuelan children with rotavirus gastroenteritis. Subgroup 2 rotavirus was shed by 85% of the children, whereas only 14% shed subgroup 1 rotavirus (one-half of them in a 3-month period). No differences were found in the occurrence of fever and vomiting between children shedding either rotavirus subgroup, but it appeared that the syndrome tended to last longer in children shedding subgroup 2 rotavirus. The monoclonal subgrouping enzyme-linked immunosorbent assay seemed to be more sensitive than an immune adherence hemagglutination assay, an enzyme-linked immunosorbent assay with polyclonal antibodies, or the electrophoretic analysis of RNA extracted from the virus. Overall, 99% of the specimens could be subgrouped by this assay.

Rotavirus shedding by newborn children

We studied the shedding of rotavirus by newborn children in the nurseries of a large maternity hospital in Caracas, Venezuela, throughout the year 1982. Sixty-two (57%) of 108 children examined shed the virus within the first few days of life. Four (6%) of the 62 children who shed rotavirus had diarrhea but only one of them required oral rehydration therapy. The rotavirus specimens were identified as subgroup 2 in an ELISA subgrouping assay that employs monoclonal antibodies. Analysis of the RNA extracted from 52 of the samples by electrophoresis revealed a similar migration pattern in all the specimens; their identity was confirmed by crosshybridization analyses which revealed a strong degree of genomic homology among the strains studied.

Inhibition of brain adenylate cyclase by A1 adenosine receptors: pharmacological characteristics and locations

When tested under conditions reducing the endogenous production of adenosine (presence of adenosine deaminase (ADA) 1.6 IU/ml; and deoxyadenosine triphosphate (d-ATP), and in the presence of both NaCl and GTP, the ADA-resistant analog phenylisopropyladenosine (PIA) inhibited the adenylate cyclase of several brain tissues. These tissues included: (1) 5 brain areas of adult rats (frontal and parietal cortex, cerebellum cortex, hippocampus and striatum)--hypothalamus and mid-brain adenylate cyclases were not inhibited by PIA; (2) astrocytes in primary cultures prepared from cerebral cortex of newborn mice; and (3) neurons in primary cultures prepared from striata of 15-day-old mouse embryos. The specificity profile of the adenosine receptor involved in the inhibition was determined in astrocytes. It was typical of an A1 adenosine receptor (high affinity of PIA; Ka app: 9 +/- 5 X 10(-9) M (n = 4) compared to the affinity of 5'-N-ethylcarboxamide adenosine (NECA); Ka app: 1.3 +/- 0.6 X 10(-7) M (n = 3). There was an excellent correlation between the affinities of several adenosine agonists and antagonists for A1 receptors coupled with an adenylate cyclase in astrocytes and for the receptors labeled with N6-cyclohexyl-[3H]adenosine in brain cortex. In adult rat striatum as well as in astrocytes and striatal neurons in culture the adenylate cyclase was inhibited by low PIA concentrations through A1 receptors and stimulated by higher concentrations through A2 receptors. In contrast, A2 receptors were not detected in adult rat cerebral cortex. In adult rat striatum, A1 and dopamine receptors coupled with an adenylate cyclase seemed to be located on different cell populations. In contrast, in astrocytes A1 and beta-adrenergic receptors coupled with adenylate cyclase were apparently located on the same cells.

Preliminary crystallographic data on cytochrome P-450CAM

The cytochrome P-450CAM monooxygenase from Pseudomonas putida has been crystallized in three forms designated orthorhombic I, tetragonal I, and orthorhombic II. Conditions and parameters of crystal growth are presented along with the preliminary x-ray diffraction data including heavy atom derivatives.

Genetic relatedness among human rotaviruses as determined by RNA hybridization

Viral RNAs from human rotaviruses were compared by gel electrophoresis and by hybridization to probes prepared by in vitro transcription of two well-characterized laboratory strains (Wa and DS-1). Also, the viral RNAs were compared by hybridization to probes prepared from three of the test viruses. Thirteen specimens (diarrheal stools) were obtained from infants and children 5 to 21 months old on a single day at the emergency ward of the Caracas Children's Hospital, and an additional specimen was obtained from the same hospital 6 months before. When the electrophoresed viral RNAs were stained with ethidium bromide and examined by UV light, five different migration patterns (electropherotypes) were distinguished on the basis of differences in mobility of the RNA segments. The hybridization technique that was employed permitted only qualitative comparisons of corresponding genes of different human rotaviruses. Ten of the specimens contained enough virus to yield sufficient RNA for hybridization studies. Eight of the viruses studied by hybridization contained 4 to 11 genes that reacted specifically with the Wa probe to yield double-stranded RNA segments with a mobility similar to that of Wa viral RNA or test virus RNA. The other two viruses contained 11 genes that reacted specifically with the DS-1 hybridization probe to yield double-stranded RNA segments with a mobility similar to DS-1 viral RNA or test virus RNA. A more complex picture emerged when hybridization probes were prepared from three of the test viruses and used to compare the different electropherotypes. Corresponding genes that exhibited similar migration did not necessarily exhibit homology when studied by hybridization. Also, some corresponding genes that exhibited homology did not have the same mobility by gel electrophoresis.

Autoradiographic detection and characterization of a Chinese hamster ovary cell mutant deficient in fucoproteins

Autoradiography of colony replicas immobilized on filter paper was used to isolate a Chinese hamster ovary cell line deficient in incorporation of radiolabeled fucose into a trichloroacetic acid-insoluble fraction. This cell line, called 62.1, has the same growth rate at 37 degrees C as wild-type cells, but incorporates five times less fucose into acid-insoluble radioactivity. Chemical analysis of fucose bound to macromolecules also showed a fivefold reduction in the mutant. The fucoproteins of the mutant cell line differ qualitatively from those of wild-type cells as visualized by SDS gel electrophoresis fluorography; no differences were detected between total proteins as visualized by coomassie blue staining. The macromolecular sialic acid content of the mutant was somewhat higher than the wild type (20%). Studies of the synthesis of the glycoprotein of vesicular stomatitis virus in mutant and wild-type cells showed that the mutant is unable to synthesize complex-type N-linked oligosaccharides. Enzyme assays show that ths defect in the mutant is due to reduction in UDP-N-acetylglucosamine-glycoprotein N-acetyl-glucosaminyltransferase, a key enzyme in the assembly of complex glycopeptides. Hybridization studies have shown that mutant 62.1 has common mutations belonging to the same complementation group as mutant PhaR1-1. This latter mutant was previously isolated using lectin resistance by Stanley et al. (1975) and was also deficient in the above N-acetyl-glucosaminyltransferase.

[Syndromic diversities in Creutzfeldt-Jakob disease: neurophysiological and histopathological correlates]

Two syndromatic forms of Creutzfeldt-Jakob disease are illustrated with data from two cases confirmed by necropsy and studied by means of electroencephalogram, evoked potential recording and neuropathological techniques. One of the cases presented the typical hypersynchronous periodic discharges through to be characteristic of this disease. The other did not exhibit epileptiform discharges, showing an evolution in which progressive diffuse slowing was the prominent feature. Cortical spongyosis, gliosis, and neuronal lose were intense in the case showing spikes, and moderate in the one without spikes. Subcortical involvement was similar in both cases. This different topography of pathological involvement might explain, in addition to electroencephalographic findings, the different behavior of somatosensory evoked potentials, which were of larger amplitude in the case showing epileptiform discharges, although in both cases deterioration of clinical state was accompanied by a progressive amplitude decrement in the evoked potential. Sleep induced by barbiturates was disrupted in the case with spikes, its pattern being closer to normal in the case with less severe cortical involvement. A Wada test demonstrated that discharges in the hemispheres were independent. Spike periodicity is discussed. It is postulated that the heavier involvement of cortical layers II to IV deprive the remaining pyramidal cells of inhibitory influences, a condition which might explain the generation of periodic spike discharges.

Selection of mutant Chinese hamster ovary cells altered glycoproteins by means of tritiated fucose suicide

Mutant Chinese hamster ovary cells altered in glycoproteins have been isolated by selecting for ability to survive exposure to [6-3H]fucose. Mutagenized wild-type cells were permitted to incorporate [3H]fucose to approximately 1 cpm of trichloroacetic acid-insoluble radioactivity per cell and then frozen for several days to accumulate radiation damage. The overall viability of the population was reduced by 5- to 50-fold. Four consecutive selection cycles were carried out. The surviving cells were screened by replica plating-fluorography for clones showing decreased incorporation of fucose into trichloroacetic acid-insoluble macromolecules. Considerable enrichment for cells deficient in fucose uptake or incorporation into proteins (or both) was found in populations surviving the later selection cycles. Two mutant clones isolated after the fourth selection cycle had the same doubling time as the wild type, but contained only 30 to 40% as much fucose bound to proteins as the wild type. Sialic acid contents of the mutants and the wild type were similar. The mutants differed quantitatively and qualitatively from the wild type and from each other with respect to total glycoprotein profiles as visualized by sodium dodecyl sulfate gel electrophoresis. Differences were also found in resistances to cytotoxicity of lectins such as concanavalin A and wheat germ agglutinin.