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Biomedical subjects

I Sarov

Publications and source records attributed to I Sarov.

At least 37 records · Page 2Linked to original sources

Rotavirus diarrhea in Jewish and Bedouin children in the Negev region of Israel: epidemiology, clinical aspects and possible role of malnutrition in severity of illness.

We conducted a 1-year prospective study in the Negev region of southern Israel to determine the epidemiologic and clinical patterns of rotavirus diarrhea. A total of 605 patients were studied, 392 Bedouins and 213 Jews, 441 of whom had diarrhea (449 episodes) and 164 did not. Rotavirus was the most common organism detected in children with diarrhea (63 of 444; 14%) but was rarely found in controls (3 of 163; 2%) (P less than 0.001). In 22% (12 of 54) of the rotavirus-positive patients, at least one other organism was also detected. The rate of rotavirus detection decreased as age increased, from 18% in the first year to 8% in the third year of life. Hospitalization with rotavirus diarrhea occurred more frequently in the summer. However, during winter, when diarrhea was less prevalent in the community, the proportion of cases associated with rotavirus was higher. Compared with controls, malnourished children were more likely to be hospitalized. However, rotavirus was detected in similar proportions among well-nourished and malnourished cases with diarrhea. The most prevalent rotavirus serotype was type 1 (in 69%), followed by types 4 and 2 (18 and 13%, respectively). We estimated that during the study period, approximately 2% of all Bedouin infants vs. only 0.2% of Jewish infants were hospitalized with rotavirus disease in their first year of life. Clinical signs and symptoms and stool appearance were not useful in predicting rotavirus detection. Malnutrition seems to be an important indicator of disease severity, which may explain why the toll of rotavirus-associated morbidity and mortality is particularly high among children in developing countries.

Acute Disease↗

Leishmania major: inhibition of the chemiluminescent response of human polymorphonuclear leukocytes by promastigotes and their excreted factors.

The effect of various leishmanial preparations on the chemiluminescent response (CR) of human polymorphonuclear leukocytes (PMN) was studied. Almost no CR was observed with PMN stimulated with either Leishmania promastigotes or their excreted factors (EFs). Promastigotes added to PMN stimulated with phorbol myristate acetate (PMA), at a proportion of 20 to 1, respectively inhibited approximately 80-83% of the CR activity. Leishmanial promastigotes, whether live or dead, infective or non-infective as well as whole parasite homogenates, soluble and insoluble fractions, all decreased the CR of the PMN (PMN-CR). A similar effect was also observed with leishmanial EFs. The degree of inhibition was dose dependent and increasing the amount of EFs in the reaction mixture resulted in decrease of the PMN-CR. More than 80% of the total activity of the PMN-CR was inhibited by 500 micrograms EFs added at zero time to the reaction mixture. The inhibition of PMN-CR obtained from a patient suffering from a chronic infection caused by L. major was not significantly different from that observed with PMN from normal donors. The present study suggests that the PMN-CR is impaired by the Leishmania parasites and their EFs and thus may allow a greater survival of the parasites within these cells.

Animals↗

Tumor necrosis factor alpha and prostaglandin E2 production by human monocyte-derived macrophages infected with spotted fever group rickettsiae.

Infection of macrophages by intracellular parasites might modulate production of tumor necrosis factor (TNF) and prostaglandin E2 (PGE2), which, in turn, might have a profound effect on the outcome of the infection in vivo. In this study we examined in an in vitro system, the rickettsial yield in human monocyte-derived macrophages (MdM) and the PGE2 and TNF production by MdM infected with Rickettsia conorii RC, Casablanca strain) or Israeli spotted fever (ISF, G-212 strain). TNF and PGE2 were determined in the media of MdM infected with RC or ISF. TNF reached maximum levels 24 h post-infection and then declined, while PGE2 levels increased continuously during the infection up to 96 h post-infection. Addition of dexamethasone inhibited both TNF and PGE2 production and enhanced rickettsial yield in MdM. Inhibition of PGE2 production by indomethacin resulted in increased production of TNF from rickettsial-infected MdM, while addition of PGE2 caused partial inhibition of TNF production from infected MdM.

Dexamethasone↗

Inhibition of growth of Chlamydia trachomatis by tumor necrosis factor is accompanied by increased prostaglandin synthesis.

Development of Chlamydia trachomatis (L2/434/Bu) in HEp-2 cells was inhibited by treatment of the cells with recombinant human alpha tumor necrosis factor (TNF). In the infected cultures that were treated with TNF, high concentrations of prostaglandin E2(PGE2) were detected, exceeding by far the concentrations found in TNF-treated but uninfected cells or in infected cells that were not treated with TNF. PGE2 levels increased gradually for 2 days after infection. Raising the tryptophan concentration in the culture medium, which reversed the inhibition of chlamydial replication by TNF, also blocked the increase in PGE2 formation. However, neutralizing antibodies to beta interferon, which also interfered with the antichlamydial effect of TNF, did not decrease PGE2 formation. Excessive formation of PGE2 by cells infected with chlamydiae and treated by TNF might be related to some of the complications associated with chlamydial infection.

Chlamydia trachomatis↗

Inhibition of Rickettsia conorii growth by recombinant tumor necrosis factor alpha: enhancement of inhibition by gamma interferon.

Purified human recombinant tumor necrosis factor alpha (rTNF-alpha) inhibited the growth of Rickettsia conorii (Casablanca strain) in HEp-2 cell culture. The effect was observed when the cells were pretreated with rTNF-alpha or when rTNF-alpha was added after adsorption of the rickettsiae. The inhibitory effect of rTNF-alpha on rickettsial growth was enhanced by gamma interferon. Cycloheximide had no effect on inhibition of the rickettsial yield, suggesting that de novo protein synthesis is not required for the inhibitory effect of rTNF-alpha. The addition of tryptophan partially abolished the inhibitory effect of rTNF-alpha and rTNF-alpha plus gamma interferon.

Cell Line↗

Antinuclear autoantibodies in sera of patients with IgA nephropathy.

IgA nephropathy (IgAN), assumed to be a chronic immune complex glomerulonephritis, has been sometimes associated with various autoimmune diseases and autoimmune phenomena including autoantibody production. The current study was aimed at thoroughly investigating the frequency of raised autoantibody titers against five common nuclear autoantigens in a large number of patients with IgAN as well as patients with other primary immune complex glomerulopathies and normal controls. The incidence of autoantibodies (greater than 2 SD less than 3 SD of controls) in the IgAN group ranged between 13% in the case of anticardiolipin antibodies, and 19% in the case of antiribonucleoprotein antibodies, yet was not found to be significantly different from the incidence observed in the other control groups. In none of the subjects a titer above 3 SD of the means of controls was found. Our study clearly points to the fact that IgAN, while being an immune-mediated disease, is not a clear-cut autoimmune condition. The finding of autoantibodies in these patients may be merely incidental.

Antibodies, Antinuclear↗

Serum-specific antibodies for Chlamydia trachomatis in preterm premature rupture of the membranes.

A case control study was performed to examine possible morbidity associated with Chlamydia trachomatis in 15 pregnant women with idiopathic preterm premature rupture of the membranes (PROM; group A), and in two control groups, 35 healthy preterm pregnant women (group B), and 43 healthy pregnant women at term (group C). Serum C. trachomatis IgG and IgA specific antibodies were determined using the single serovar (L2) inclusion immunoperoxidase assay. There were no significant differences in the prevalence rate of elevated levels of chlamydia IgG specific antibodies (titer greater than or equal to 1:128) between pregnant women suffering from idiopathic preterm PROM, as compared to healthy preterm and term pregnant women (20, 28 and 26%, respectively). Nor were there any significant differences in the prevalence rate of elevated levels of chlamydia IgA specific antibodies (titer greater than or equal to 1:16) between pregnant women with idiopathic preterm PROM, as compared to healthy preterm and term pregnant women (20, 20 and 17%, respectively). These findings do not support the assumption that C. trachomatis may play role in preterm PROM.

Adult↗

Detection of specific IgA antibodies to varicella zoster virus in serum of patients with Ramsay Hunt syndrome.

Varicella zoster virus (VZV)-specific IgG and IgA antibody titers were determined in serial serum samples of 23 patients with Ramsay Hunt syndrome by the immunoperoxidase assay. Varicella zoster virus-specific IgG antibodies were found in the first serum samples of all the patients. In 80% of 20 patients in whom a serum sample was available within 5 days after the onset of the disease. VZV-specific IgA antibodies were detected. The second serum sample was VZV-specific IgA-positive in all of the patients. While all the healthy age- and sex-matched control subjects had VZV-specific IgG antibodies, VZV-specific IgA antibodies were detected in a low titer (dilution = 2) in only three of the subjects. By using VZV-specific IgA antibody titers greater than or equal to 2 and greater than or equal to 4 by the immunoperoxidase assay as a "cutoff" for younger and older patients with Ramsay Hunt syndrome, respectively, an early diagnosis of the disease can be obtained in 89% of the younger and in 64% of the older patients by a single serum sample.

Adolescent↗

The prevalence of IgG antibodies to spotted-fever group rickettsiae among urban and rural dwelling children in southern Israel.

The prevalence of IgG antibodies to spotted-fever group rickettsiae was studied in a sample of 1,055 healthy children aged 2-17 years, residents of the desert Negev region of southern Israel. Groups of children from 5 different places of residency were tested: (1) urban children from the city of Beer-Sheva; (2) children from Omer, a suburb of the city; (3) children from rural communes ("kibbutz"); (4) children from small agricultural settlements ("moshav"); and (5) seminomadic bedouin children. Overall 40 sera (3.8%) were positive by the indirect immunofluorescent antibody assay at a titer of 40. The prevalence rate was 3.6% in males and 4.0% in females. Age-specific prevalence rates for the 2-5, 6-9, 10-13 and 14-17 year old groups were 2.0, 5.4, 4.1 and 3.6% respectively. The prevalence rates by place of residency were: urban 3.3%, suburban 3.3%, "kibbutz" 3.8%, "moshav" 5.1% and seminomadic children 3.3%, and did not differ by socio-economic status as measured by degree of crowding. The results indicate that spotted fever is endemic in all human habitats in the Negev region. Our data do not support association to sex or socio-economic status of the children tested. Lack of cumulative prevalence rates with increasing age suggests that antibodies may wane to undetectable levels in the years following the infection.

Adolescent↗

Cutaneous leishmaniasis serodiagnosis by immunoperoxidase assay.

Immunoperoxidase assay was used for the determination of serum-specific anti-leishmanial IgG antibodies in 65 patients with cutaneous leishmaniasis (CL), in 5 with visceral leishmaniasis (VL) and in 84 controls. A significant difference was observed between CL and VL sera and the control sera when either Leishmania major, L. donovani or L. aethiopica intact promastigotes were used as antigens. CL patients showed similar activity against L. major and L. donovani antigen (titers 4-64 and less than 2-64 respectively), whereas VL patients showed a higher activity with the homologous antigen L. donovani (titers 128-2,048). A high and significant correlation was demonstrated between immunoperoxidase assay, immunofluorescent assay and radioimmunoassay. No cross-reactivity was found with sera from malaria patients.

Adult↗

[IgA and IgG antibodies to Chlamydia in IgA nephropathy as well as in mesangiocapillary and membranous glomerulonephritis].

It might be supposed that, among the antigens causing chronic immune complex glomerulonephritis (IC GN), there are foreign materials, e.g. bacterial antigens penetrating the mucosal barrier. To put this hypothesis to the test, the presence and titres of IgA and IgG antibodies against Chlamydia (C., one of the most frequent bacteria causing mucosal inflammation) have been studied in the sera of 70 patients with IgA nephropathy (IgA NP), of 25 with mesangiocapillary GN (MCGN) and of 27 with membranous GN (MGN) using a single serovar (L2) inclusion immunoperoxidase assay. Significantly more IgA (titres greater than or equal to 8) and IgG (titres greater than or equal to 32) antibodies were found in the sera of IgA NP and MCGN patients than in healthy controls. These results are compatible with the hypothesis that there are some similarities between the clinical and morphological picture of IgA NP and MCGN. Furthermore, it may be assumed that in renal patients with an active C. infection (high IgG titres with IgA seropositivity) C. antigens may play a role in the production of nephropathogenic IC developing in antibody excess.

Adult↗

[Beta-interferon for labial and genital herpes virus infection].

19 women and 9 men, aged 15-59 (mean, 35.1), who had had recurrent lip or genital infections with herpes virus (HSV) for from 1-38 years, were treated with beta-interferon gel (100,000 IU/g), self-administered 4 times daily to the affected areas. In half the patients the drug and a placebo were given in a double-blind, cross-over study. The trial lasted 30 months. Frequency of attacks, length of each attack and its severity, and the presence of itching were noted. If there was improvement in at least 2 parameters treatment was considered successful. This was the case in about 75% of the patients. The mean number of attacks per year before and during treatment with interferon was 6.8 and 3.0, respectively (p less than 0.003) and the mean length of attacks 8.2 and 4.7 days, respectively (p less than 0.001). Results of the double-blind, cross-over test were also significant, and were similar to those for the total group. These results clearly indicate that local interferon is effective treatment for genital and labial HSV infections.

Administration, Topical↗

The association between chlamydial-specific IgG and IgA antibodies and pregnancy outcome in an in vitro fertilization program.

Chlamydial-specific IgG and IgA antibodies were determined by a single serovar (L2) immunoperoxidase assay (IPA) in the serum of all patients that have conceived in an in vitro fertilization and embryo transfer (IVF & ET) program (n = 106) and in a group of patients that went through the program at the same period of time and did not conceive (n = 94). The prevalence rate of elevated IPA IgG (titers greater than or equal to 1:128) and IPA IgA (titers greater than or equal to 1:16) specific to chlamydiae was significantly higher (P less than 0.001) in the IVF & ET pregnancy loss and nonconception groups ("failures") versus the IVF & ET term pregnancy group ("successes") (74 vs 47%, odds ratio = 4.1, and 34 vs 14%, odds ratio = 4.3, respectively). Stepwise discriminant analysis revealed that elevated specific chlamydial IgG had the greatest effect on the variance between successes and failures in this study group. Our study indicates the possible role of past or chronic active chlamydiae infection on the "take-home baby rate" in an IVF & ET program.

Adult↗

Serum IgG and IgA antibodies to Chlamydia in ectopic pregnancies.

The possible association of Chlamydia trachomatis with ectopic pregnancies was evaluated in a case-control study, comprising 35 women with ectopic pregnancy and 294 apparently healthy women who served as controls. Chlamydia-specific IgG and IgA antibodies were determined by single serovar (L2) inclusion immunoperoxidase assay (IPA). Socio-demographic characteristics, gynecological history and contraceptive methods were also evaluated. An inverse relationship was found between the educational levels and the prevalence of IgG and IgA antibodies to chlamydia. The prevalence rate of elevated IPA IgG (titer greater than or equal to 128) and IPA IgA (titer greater than or equal to 16) specific to chlamydia was significantly higher in women with ectopic pregnancy versus controls (32% vs 8%, respectively, for IgG: odds ratio = 4.9; and 26% vs 4% for IgA: odds ratio = 7.5). Chlamydia trachomatis was not isolated in cell cultures in 10 specimens available from fallopian tubes of women with ectopic pregnancy. Only 9% of the women recall having pelvic inflammatory disease (PID) indicating that most of the infections were asymptomatic. Women who did not use IUD had a higher proportion of chlamydia-specific IgG and IgA seropositives, though not statistically significant, as compared to IUD users. This study further supports the hypothesis that subclinical infection of the tube with C. trachomatis may underlie ectopic pregnancies.

Adolescent↗