Use of antiherpes drugs and the risk of Kaposi's sarcoma: data from the Multicenter AIDS Cohort Study

To determine if use of antiherpes drugs protects against the development of AIDS-associated Kaposi's sarcoma (KS), data from 935 homosexual men with AIDS from the Multicenter AIDS Cohort Study were analyzed. In nested case-control analysis, neither acyclovir use for human immunodeficiency virus infection (odds ratio [OR], 0.84; 95% confidence interval [CI], 0.56-1.26; P = .39) nor acyclovir use for any indication (OR, 1.02; 95% CI, 0.76-1.38; P = .89) was associated with a reduced risk of KS as initial AIDS diagnosis. In longitudinal analysis, acyclovir was also not protective against developing KS as a late manifestation of AIDS (after initial non-KS AIDS diagnosis). Among men with cytomegalovirus disease, ganciclovir use (relative risk [RR], 0.56; 95% CI, 0.22-1.44; P = .23) and foscarnet use (RR, 0.40; 95% CI, 0.051-3.10; P = .38) were associated (although not significantly) with a reduced risk of KS. Thus, acyclovir use does not appear to reduce the risk of KS, but further study of other antiherpes drugs such as ganciclovir and foscarnet is warranted.

Gender and race differences in bone mass during infancy

The purpose of this study was to determine whether race or gender differences in total body bone mineral content (BMC) are evident within the first 18 months of age. Total body bone mineral measurements were obtained on 64 healthy infants 1-18 months of age. There were no significant differences in age, weight, or height between race and gender groups. Taking into account weight and age, both bone mineral density (BMD) and BMC were greater in male infants compared with female infants (both, P = 0.02) and BMD was slightly higher in black infants compared with white infants (P = 0.07).

Neurodevelopmental outcome of infants with viral meningitis in the first three months of life

We prospectively evaluated the neurodevelopmental outcome of infants with documented viral meningitis to determine (1) whether deficits in physical growth, development, speech and language, hearing, or intelligence occur; and (2) if so, at what age these deficits can be detected. Sixteen infants with documented enteroviral meningitis under the age of 90 days and a control group of 13 patients matched for age, race, sex, and socioeconomic status were followed up prospectively for 3 years with annual evaluations, which included a developmental evaluation by a pediatric developmentalist, articulation and language tests by a speech-language pathologist (Sequenced Inventory of Communication Development, Receptive-Expressive Emergent Language Scale (REEL), Preschool Language Scale (PLS), Revised Peabody Picture Vocabulary Test (PPVT-R), Photo Articulation Test, audiometric screening), and intelligence tests by a psychometrist (Bayley Scales of Infant Development [BSID] and Stanford-Binet). No deficits were demonstrated in growth, development, hearing, BSID, articulation, and expressive language. Subtle but significant (P < 0.05) deficits were documented in the study group compared with the control group in the receptive component of the REEL, all subsections of the PLS, the PPVT-R, and the verbal comprehension/language-processing section (Factor II) of the Stanford-Binet. These differences could be reliably detected by 3 years of age. We conclude that viral meningitis in young infants may cause subtle deficits in language skills, particularly receptive language. We recommend that children who have had enteroviral meningitis during early infancy be monitored carefully for language development and, perhaps, receive increased language stimulation in the home prior to school entry in order to optimize their learning potential.

Expression of p53 in conjunctival melanocytic nevi. An immunohistochemical study

The objective of this study was to evaluate conjunctival nevi for p53 gene mutations. We studied 11 conjunctival nevi by immunohistochemistry with the DO7 monoclonal p53 antibody as well as the cell proliferation marker, MIB1. Of the 11 cases, 2 were negative, 2 had less than 1%, and 7 had more than 2% p53 immunopositive nuclei with no direct correlation with MIB1 positivity. Our results suggest altered expression of p53 in conjunctival nevi.

The effect of blood transfusion on tumor growth in sarcoma-bearing rats

BACKGROUND

The effect of blood transfusion on tumor growth is controversial. Under experimental conditions, even similar animal models can give varied results. This study was undertaken to characterize the nature of the effect of blood transfusion on tumor growth.

METHODS

Sixty-five Fischer 344 rats subcutaneously implanted with a methylcholanthrene-induced sarcoma were studied with additive blood transfusion at 1% tumor burden in two separate experiments. In experiment 1, the effects of syngeneic fresh whole blood transfusion (5, 10, and 15 ml/kg) and allogeneic (5 ml/kg) were tested. To determine if stored blood influenced the results, experiment 2 was performed with syngeneic blood transfusion (15 ml/kg) and allogeneic blood transfusion at 5 ml/kg. Tumor dimensions were determined daily by external measurement, and tumor weight and growth rate were calculated.

RESULTS

No significant differences in final tumor weights or tumor growth rates were found in transfused rats compared with controls. This held true for syngeneic blood transfusion regardless of dose, allogeneic blood transfusion, and regardless of whether the blood was fresh or stored.

CONCLUSIONS

Additive blood transfusion does not affect tumor growth in this animal model. This finding, together with the general inconclusiveness in the reported literature on this topic, speaks against a dominant role for the effect of blood transfusion on tumor behavior.

Interleukin-10 inhibits tumor necrosis factor production but not antigen-specific lymphoproliferation in acute Plasmodium falciparum malaria

In vivo interleukin (IL)-2, IL-4, IL-10, and interferon (IFN)-gamma production was measured at the mRNA transcript and protein levels in patients acutely infected with Plasmodium falciparum and during convalescence. Both IL-10 and IFN-gamma but not IL-2 were produced regardless of the patients' clinical severity. IL-4 production was variable. Circulating IFN-gamma and IL-10 were significantly higher in patients with severe disease (P < .01 and .001, respectively). In vitro stimulation of peripheral blood mononuclear cells (PBMC) by malarial antigens during acute infection showed that although there was no lymphoproliferation, the cells could produce IL-10 and IFN-gamma. Recombinant human IL-10 completely abolished in vitro tumor necrosis factor (TNF)-alpha production in response to malarial antigens, as well as the antigen-specific proliferative response of convalescent patients. However, anti-IL-10 was insufficient to restore proliferation of PBMC from acutely infected patients. These findings suggest that IL-10 may have an important negative feedback action on the production of inflammatory cytokines in acute falciparum malaria without contributing to the defect in antigen-specific proliferation.

Structural characterization of the lipopolysaccharide O antigens of Burkholderia pseudomallei

A serologically typical strain of Burkholderia pseudomallei (strain 304b) was found to produce two S-type lipopolysaccharides (LPS) differing in the chemical structures of their O-polysaccharide (O-PS) components. Structural analysis revealed that one O-antigenic polysaccharide (O-PS I) is an unbranched high-molecular-weight polymer of 1,3-linked 2-O-acetyl-6-deoxy-beta-D-manno-heptopyranose residues. The other LPS O antigen (O-PS II) is an unbranched polymer of repeating disaccharide units having the structure -3)-beta-D-glucopyranose-(1-3)-6-deoxy-alpha-L-talopyranose-(1- in which ca. 33% of the L-6dTalp residues bear 2-O-methyl and 4-O-acetyl substituents while the other L-6dTalp residues carry only 2-O-acetyl substituents. Analysis of a serologically atypical strain of B. pseudomallei (strain 824a) produced a single LPS O-PS which was chemically identical to the 6-deoxy-D-manno-hepan O-PS I. The production of two distinct LPS raises the interesting question of their relative immunogenicities and consequently their relative importance for diagnostic serology and for the possible development of conjugate vaccines.

Pharmacokinetics of zidovudine and didanosine during combination therapy

While the combination of zidovudine and didanosine is used in HIV-infected patients with more advanced disease, the possibility of a pharmacokinetic interaction between these two drugs remains controversial. Zidovudine doses of 50, 100, and 200 mg, combined with 67, 167, and 250 mg of didanosine were evaluated in 11 asymptomatic HIV-infected patients after receiving 24 weeks of combination therapy in AIDS Clinical Trials Group protocol 143. The pharmacokinetic parameters of zidovudine and didanosine were similar to those obtained with each drug given as monotherapy in other previously published studies. The renal clearance and urinary recovery of glucuronidated zidovudine was reduced when zidovudine was given in combination with didanosine, possibly due to competition for renal tubular secretion. These data suggest that no clinically important pharmacokinetic interaction occurs when zidovudine and didanosine are given together.

Sequence analysis and comparison of ribosomal DNA from bovine Neospora to similar coccidial parasites

The nuclear small subunit ribosomal RNA (nss-rRNA) gene sequence of Neospora spp. isolated from cattle was analyzed and compared to the sequences from several closely related cyst-forming coccidial parasites. Double-stranded DNA sequencing of 5 bovine Neospora spp. isolates (BPA1-4), 2 Neospora caninum isolates (NC-1 and NC-3), and 3 Toxoplasma gondii isolates (RH, GT-1, CT-1) were performed and compared to each other, as well as to other sequences available in GenBank for the NC-1 isolate, Sarcocystis muris, and Cryptosporidium parvum. There were no nucleotide differences detected between the Neospora spp. isolates from cattle and dogs. Four nucleotide differences were consistently detected when sequences of Neospora spp. isolates were compared to those of the T. gondii isolates. These results indicate that Neospora spp. and T. gondii are closely related, but distinct, species.

High-resolution comparative mapping of the proximal region of the mouse X chromosome

The murine homologues of the loci for McLeod syndrome (XK), Dent's disease (CICN5), and synaptophysin (SYP) have been mapped to the proximal region of the mouse X chromosome and positioned with respect to other conserved loci in this region using a total of 948 progeny from two separate Mus musculus x Mus spretus backcrosses. In the mouse, the order of loci and evolutionary breakpoints (EB) has been established as centromere-(DXWas70, DXHXF34h)-EB-Clcn5-(Syp, DXMit55, DXMit26)-Tfe3-Gata1-EB-Xk-Cybb-telomere. In the proximal region of the human X chromosome short arm, the position of evolutionary breakpoints with respect to key loci has been established as DMD-EB-XK-PFC-EB-GATA1-C1CN5-EB-DXS1272E-ALAS2-E B-DXF34-centromere. These data have enabled us to construct a high-resolution genetic map for the approximately 3-cM interval between DXWas70 and Cybb on the mouse X chromosome, which encompasses 10 loci. This detailed map demonstrates the power of high-resolution genetic mapping in the mouse as a means of determining locus order in a small chromosomal region and of providing an accurate framework for the construction of physical maps.

Randomized study of didanosine monotherapy and combination therapy with zidovudine in hemophilic and nonhemophilic subjects with asymptomatic human immunodeficiency virus-1 infection. AIDS Clinical Trial Groups

To evaluate the safety and efficacy of didanosine (ddl) monotherapy and three different combinations of zidovudine (ZDV) and ddl in asymptomatic human immunodeficiency virus-1 (HIV-1) infection, we conducted an open-label, phase I/II study in 126 asymptomatic HIV-1-infected hemophilic and nonhemophilic subjects with a CD4 count of 200 to 500/mm3 stratified for prior zidovudine treatment and baseline CD4 count. Study arms included arm A, low-dose combination (ZDV 150 mg and ddl 134 mg, daily); arm B, moderate-dose combination (ZDV 300 mg and ddI 334 mg, daily); arm C, high-dose combination (ZDV 600 mg and ddl 500 mg, daily), and arm D, ddl monotherapy (ddl 500 mg, daily). Earlier, more frequent hepatotoxicity was experienced by hemophilic subjects (P = .008), but there were no differences in toxicity between treatment arms (P = .51), nor were there any differences in the rate of development of clinical endpoints by treatment (P = .41). Smaller median CD4 increases occurred over the first 12 weeks for arms A and D, 44/mm3 and 42/mm3, than arms B and C, 105/mm3 and 114/mm3, respectively, (P = .015). Hemophilia status (P = .0004) and prior ZDV experience (P = .044) independently predicted weaker CD4 responses during the first 12 weeks of treatment. Using a regression model and adjusting for hemophilia status, prior ZDV treatment, and baseline CD4, there was a significant reduction in quantitative viral load from baseline by week 12 for all treatment arms combined (P = .0001), with significantly lower median percent reduction for arm A (56.3%) than arms B, C, and D (94.6%, 98.5%, and 91.9%, respectively, P = .015). Although greater hepatoxicity and weaker CD4 responses occur in hemophilic subjects, didanosine monotherapy and combination therapy with zidovudine are safe and effective in asymptomatic HIV-1-infected patients.

Sulphasalazine-induced lupus in psoriatic arthritis

Lupus syndromes have been described in rheumatoid arthritis and inflammatory bowel diseases treated with sulphasalazine. We describe two cases of lupus with clinical and serological disease, developing in seronegative, immunologically nude psoriatic arthritis following sulphasalazine treatment. On cessation of sulphasalazine the clinical and serologic features of lupus disappeared. This suggests that the lupus syndrome was induced by sulphasalazine rather than unmasked by it.

Treatment of typhoid fever: randomized trial of a three-day course of ceftriaxone versus a fourteen-day course of chloramphenicol

To compare the efficacy of a short course of ceftriaxone with a standard course of chloramphenicol for typhoid fever, a randomized trial was conducted in 46 patients (30 adults and 16 children) who were blood culture-positive for Salmonella typhi or S. paratyphi. Ceftriaxone was given intravenously once a day for three days to 15 adults at a dose of 2 g/day and to eight children at a dose of 50 mg/kg/day. Chloramphenicol was given orally four times a day to an equal number of patients at a dose of 60 mg/kg/day until defervescence, followed by 40 mg/kg/day for a total of 14 days. Clinical cure without complications or relapse occurred in 19 patients (83%) treated with ceftriaxone and in 20 patients (87%) treated with chloramphenicol (P > 0.05). Four patients with clinical failures in the ceftriaxone group included two with fever lasting six days or more, one with altered sensorium, and one with relapse; three patients treated with chloramphenicol developed leukopenia and thrombocytopenia and were switched to amoxicillin therapy. Bacteriologically, blood cultures of all 46 patients were sterile three days after the start of treatment, and remained so through day 15 of follow-up. These results extend previous observations on the efficacy of ceftriaxone in short courses for both adults and children with typhoid fever.

Regulation of insulin-like growth factor binding protein-1 during the 24-hour metabolic clock and in response to hypoinsulinemia induced by fasting and Sandostatin in normal women

OBJECTIVE

To establish the relation of insulin-like growth factor-I (IGF-I) and IGF-binding protein-1 (IGFBP-1) with 24-hour metabolic excursions in normal healthy women and in response to acute interruption of metabolic homeostasis by hypoinsulinemia.

METHODS

Hourly blood samples during the 24-hour metabolic clock were obtained from seven normally cycling women. Uniform dietary composition (50% carbohydrate, 35% fat, and 15% protein) and timing of meals (8 AM, 12 PM, and 6 PM) were prescribed. Daytime hypoinsulinemia was induced by omitting meals and by Sandostatin (100 micrograms) administration. Changes in serum levels of glucose, insulin, cortisol, IGF-I, and IGFBP-1 were measured.

RESULTS

The diurnal pattern of serum IGFBP-1 levels during the 24-hour metabolic clock was characterized by a rapid fall during the feeding phase of the day and a progressive 3.5-fold rise during nocturnal fasting; IGF-I levels were unchanged. Changes in IGFBP-1 levels were in parallel to those of cortisol and were inversely related to increases in glucose (80%) and insulin (tenfold) levels after each meal and to their decline during nocturnal fasting. Daytime fasting and administration of Sandostatin were accompanied by rapid and sustained increases in IGFBP-1 when insulin levels declined to 54 +/- 20 pmol/L.

CONCLUSIONS

With constant levels of IGF-I, the diurnal rhythm of IGFBP-1 may subserve a physiologic function by coordinating insulin and IGF-I action with substrate availability. Fluctuations of insulin levels during the 24-hour metabolic clock in normal women appear to serve as a signal, with an inhibitory effect on IGFBP-1 production when levels are above 70 pmol/L and a stimulatory effect at levels below 70 pmol/L. These findings provide a basis for future investigations in women with nutritionally related reproductive disorders.

Hepatitis E in a Canadian traveller

Hepatitis E is clinically indistinguishable from hepatitis A and is caused by an enterically transmitted rna virus that is endemic in developing countries of Asia, Africa, the Middle East and North America. This report describes a Canadian traveller to Nepal, Thailand and India with one of the first confirmed cases of hepatitis E reported in Canada. Although this disease is usually self-limited with no known sequelae, it may produce fulminant hepatitis with a high case fatality rate in pregnancy. Diagnosis can be confirmed by serological tests. Apart from strict food and beverage hygiene, there are presently no prophylactic measures against this disease, and pregnant women in the third trimester should avoid travel to endemic areas.

Diagnosis of cytomegalovirus infections by shell vial assay and conventional cell culture during antiviral prophylaxis

A total of 3,552 specimens for conventional cytomegalovirus (CMV) culture and shell vial assay for CMV immediate-early antigen were obtained during a prospective randomized trial for prophylaxis of CMV disease after liver transplantation. Prophylaxis with ganciclovir for 2 weeks and then high-dose acyclovir for 2.5 months was compared with high-dose acyclovir alone for 3 months. During the first 12 weeks after transplantation, when the patients were on prophylaxis, there were significantly more clinical samples positive by the shell vial assay and negative by standard culture in comparison with the number of samples obtained from weeks 13 to 24, after prophylaxis was discontinued, that were positive by the shell vial assay and negative by standard culture. In contrast, significantly fewer samples were positive by both the shell vial assay and standard culture during the first 12 weeks compared with the number obtained 13 to 24 weeks after transplantation that were positive by both methods. Samples positive by the shell vial assay only were obtained significantly more frequently from patients with asymptomatic than symptomatic CMV infections, while samples positive by both methods were obtained significantly more often from patients with symptomatic CMV infection. It was concluded that antiviral prophylaxis with high-dose acyclovir or ganciclovir and then high-dose acyclovir and asymptomatic CMV infection are associated with a decrease in the level of CMV isolation by standard cell culture in comparison with that by the shell vial assay.

Investigation of cytomegalovirus infection as a risk factor for coronary atherosclerosis in the explanted hearts of patients undergoing heart transplantation

Infection with a human herpes virus, particularly cytomegalovirus (CMV), has been hypothesized to be a cofactor in the development of atherosclerosis in humans. We investigated the association of prior CMV infection with the presence of atherosclerosis in the coronary arteries of the native heart of 314 individuals undergoing heart transplantation. Age, male gender, race, tobacco use, and previous general and cardiac surgery were also studied as covariables. Factors associated with the presence of coronary atherosclerosis by univariate analysis were age greater than the median of 48 years (odds ratio [OR] = 5.9, 95% confidence intervals [CI] 3.0-11.6; P < 0.0001), tobacco use (OR = 3.8, 95% CI 2.1-7.0; P < 0.005), CMV seropositivity (OR = 3.1, 95% CI 1.8-5.5; P < 0.001), and male gender (OR = 3.0, 95% CI 1.6-5.4; P < 0.0005). When patients were divided into quartiles based on age, coronary atherosclerosis was shown to be associated with CMV seropositive status only in the youngest quartile of patients (OR = 3.6, 95% CI 1.4-8.9; P < 0.01) but not in the older three quartiles of patients (OR = 0.9, 95% CI = 0.3-2.4; P > 0.5). In multiple logistic regression analyses, CMV seropositivity was not a significant independent variable in the whole group of patients (P = 0.13) but remained a significant variable in the youngest quartile of patients (P = 0.01). However, 43% of these younger patients and 29% of all patients with coronary atherosclerosis were seronegative for CMV.(ABSTRACT TRUNCATED AT 250 WORDS)

Advances in understanding cytomegalovirus infection after transplantation

Susceptibility to infection and disease caused by CMV varies with the degree of immunosuppression, the antecedent immunity to CMV, the source of the virus, and a complex set of host responses. These responses include the development of humoral and cellular immunity and also immunopathologic responses. HLA-restricted responses may facilitate CMV disease by facilitating the survival and activation of latently infected cells, or by facilitating MHC-class I or class II cellular immune responses underlying both protective effects and pathologic inflammation.

Pharmacokinetics of ceftriaxone in patients with typhoid fever

Ceftriaxone in short courses has emerged as an effective alternative to chloramphenicol for the treatment of typhoid fever. To study the pharmacokinetics of ceftriaxone in acute typhoid fever, 10 febrile Nepalese adolescents and young adults with blood culture-positive illness were treated with 3 g of ceftriaxone (intravenous infusion for 30 min) daily for 3 days. On the 1st and 3rd day of treatment, blood and urine samples were collected at defined intervals for measurements of drug concentrations. Kinetic parameters including concentrations at the end of infusion (Cmax) and 24 h after the end of infusion (Cmin), elimination half-life (t1/2), area under the plasma concentration-time curve (AUC), total plasma clearance, renal clearance, percentage excreted in urine, and volume of distribution were estimated. On day 1, mean values were as follows: Cmax, 291 micrograms/ml; Cmin, 21.7 micrograms/ml; plasma t1/2, 5.2 h; AUC, 1,428 micrograms.h/ml; total plasma clearance, 37 ml/min; renal clearance, 19 ml/min; percentage excreted in urine, 49.7%; and volume of distribution, 16.1 liters. Mean values on day 3 were not significantly different from those on day 1. Compared with published values for healthy volunteers who received the same dose, our mean t1/2s and AUCs were lower and our mean total plasma clearances, renal clearances, and volumes of distribution were higher. The good clinical responses of these patients to therapy and the adequate Cmins support the use of ceftriaxone once daily for the treatment of typhoid fever.

EBV gene expression, EBNA antibody responses and EBV+ peripheral blood lymphocytes in post-transplant lymphoproliferative disease

Epstein-Barr virus (EBV) is associated with the development of several B cell malignancies including Burkitt's lymphoma (BL), post-transplant lymphoproliferative disease (PTLD), and AIDS-related lymphomas. The latter two diseases result from EBV-driven B cell proliferation in the absence of normal immunosurveillance and as such, represent a heterogenous family of lymphoproliferative disorders. This article reviews studies on EBV gene expression and antibody development in PTLD and introduces recent information on the levels of EBV+ peripheral blood lymphocytes to discuss possible mechanisms of pathogenesis under varying conditions of immunosuppression.