Growth patterns reflect response to antiretroviral therapy in HIV-positive infants: potential utility in resource-poor settings

Laboratory monitoring of HIV-infected children is the current standard of care in the United States to guide the appropriate use of antiretroviral therapy (ART). Although ART is becoming a reality in some developing countries, laboratory monitoring of ART is costly, necessitating creative approaches to monitoring. As an initial step to guide monitoring of HIV progression in low resource settings, we assessed the utility of the physical examination to predict clinical progression of HIV. We conducted a retrospective cohort study of HIV-infected children using data from Pediatric AIDS Clinical Trials Group Protocol 300. We developed a clinical predictive model, and compared the utility of the clinical model to the change in HIV RNA viral load as diagnostic tests of ART failure. The clinical model incorporated treatment regimen, age, and height velocity: a three-level clinical predictive model provided likelihood ratios of 0.3, 3.9, and 14. For decline in RNA the likelihood ratios were 0.2 (> 1 log decline), 1.4, and 3.5 (> log increase). We developed a simple clinical predictive model that was able to predict clinical progression of HIV after initiation of new ART. The clinical model performed similarly to using changes in HIV RNA viral load. These data should be validated internationally and prospectively, because the test subjects were from a resource rich environment and growth patterns in undernourished children may be impacted differently by HIV and its treatment. The model was most pertinent to children 36 months of age or younger, and was conducted in children receiving monotherapy and dual therapy.     

HLA associations in insulin-dependent diabetes: search for heterogeneity in different groups of patients from a homogeneous population

A total of 317 unrelated Danish patients with insulin-dependent diabetes mellitus (IDDM) have been HLA-DR typed and the antigen and phenotype frequencies compared with those in 1177 unrelated Danish controls. The strong positive associations with DR3 and 4 and the strong negative one with DR2 were confirmed, and the remaining antigens showed a hierarchy from weakly positive to strongly negative associations: DRw9, w8, 1, 5, w6, 7. The study population included various special groups of patients selected in order to study heterogeneity: very early (less than 5 years) and very late (greater than 40 years) onset IDDM, pregnancy-induced IDDM, IDDM nephropathy, and long-term (greater than 40 years) survivors without complications. When comparing these groups, the following minor differences were seen: the DR3,4 phenotype is significantly (p = .02) more frequent in IDDM with onset before age 20 (35%) than in other cases (24%), and in familial IDDM (48%) than in other cases (28%); the frequency of the DR4 antigen was significantly (p = .008) more frequent in long-term survivors (86%) than in other patients (69%), while it was significantly (p = .02) less frequent in IDDM nephropathy (63%) than in long-term survivors. However, apart from the age-at-onset heterogeneity, which was suspected a priori, these differences may be due to chance, and the main conclusion of this study is that the HLA-DR associations in IDDM are indeed extraordinarily homogeneous irrespective of the clinical characteristics at onset and course of the disease.     

HLA-DP and bonemarrow transplantation: DP-incompatibility and severe acute graft versus host disease

Thirteen recipients of HLA-haploidentical, DR compatible bone marrow (BM) and the corresponding BM donors were HLA-DP typed using primed lymphocyte typing (PLT). Severe acute GVHD (greater than or equal to grade 2) developed within 3 months after BM-transplantation in all of eight recipients of DP incompatible BM, but in none of five recipients of DP-compatible BM. This difference was highly significant (p less than 0.001, Fisher's exact test). Moreover, severe acute GVHD was significantly increased in recipients of haploidentical, DR compatible, but DP incompatible BM as compared to severe acute GVHD in 88 recipients of HLA-identical BM (p less than 0.0001). In contrast, there was no difference in acute GVHD between recipients of haploidentical, DR and DP compatible BM and recipients of HLA-identical BM. The data presented here provide strong evidence for the first time that HLA-DP antigens play a role as transplantation antigens.     

A controlled trial of treatment of acquired immunodeficiency in severe measles with thymic humoral factor.

A randomized controlled trial of treatment with thymic humoral factor (THF) in 20 children with severe complicated acute measles infection, resulted in objective benefit as evidenced by improvement in the ESR and a fall in C-reactive protein, fewer complications and a reduced incidence of secondary herpes infection. An increased ratio of helper to suppressor T cells (OKT4/OKT8 ratio) and a greater lymphocyte transformation response to phytohaemagglutin was seen in those children receiving THF. We conclude that THF treatment helps to prevent the development of complications particularly secondary viral infections possibly by enhancing cell-mediated immune responses.     

The western Australian court diversion service: Client profile and predictors of program completion,sentencing and re‐offending

The Western Australian Court Diversion Service (CDS) is a post‐conviction / pre‐sentence program that aims to divert substance‐using offenders from the prison system and into treatment programs. It has been in operation since 1988, though a formal evaluation has not been conducted. The present study evaluated the outcomes for offenders referred to the program in relation to program completion, sentencing and re‐offending. It utilised a quasi‐experimental within groups design using data from client files from January 1998 to June 1999. Offenders who had higher motivation, attended treatment regularly and had less than 20 prior convictions were more likely to complete the program. A custodial sentence was more likely if the offender was male, had committed a serious offence, had more than 30 prior convictions, had lower motivation and had not completed the CDS program. Predictors of re‐offending included lower motivation and a previous custodial sentence. The offender's level of motivation to change and number of prior convictions were significant predictors of all three outcomes: program completion, sentencing and re‐offending. The findings highlight the importance of considering offender characteristics when assessing eligibility for diversion programs, addressing offender motivation within diversion programs and considering issues of which offenders are most likely to benefit from which programs.     

Histamine receptors in the isolated human middle meningeal artery. A comparison with cerebral and temporal arteries

The subtypes of histamine receptors mediating dilatation of human meningeal arteries have been tested in vitro, using "selective" antagonists, and compared with cerebral and temporal arteries previously examined. Dilatory responses were tested after preconstriction with prostaglandin F2 alpha. Both mepyramine and cimetidine caused a parallel shift to the right of the histamine concentration-response curve, suggesting the presence of both H1- and H2-receptors. Combined treatment with mepyramine and cimetidine caused further displacement of the concentration-response curve to the right. Schild analysis indicated pA2 values of 6.3 for cimetidine and 9.8 for mepyramine in situations of near complete blockade of either of the receptors. Both H1- and H2-receptors seem of importance for the histamine-induced dilatation in meningeal arteries and neither appear to dominate. The data considered in conjunction with our previous findings support the finding that experimental histamine-induced headache due to vasodilatation is intracranial of origin.     

Tufted puffin reproduction reveals ocean climate variability

Anomalously warm sea-surface temperatures (SSTs) are associated with interannual and decadal variability as well as with long-term climate changes indicative of global warming. Such oscillations could precipitate changes in a variety of oceanic processes to affect marine species worldwide. As global temperatures continue to rise, it will be critically important to be able to predict the effects of such changes on species' abundance, distribution, and ecological relationships so as to identify vulnerable populations. Off the coast of British Columbia, warm SSTs have persisted through the last two decades. Based on 16 years of reproductive data collected between 1975 and 2002, we show that the extreme variation in reproductive performance exhibited by tufted puffins (Fratercula cirrhata) was related to changes in SST both within and among seasons. Especially warm SSTs corresponded with drastically decreased growth rates and fledging success of puffin nestlings. Puffins may partially compensate for within-season changes associated with SST by adjusting their breeding phenology, yet our data also suggest that they are highly vulnerable to the effects of climate change at this site and may serve as a valuable indicator of biological change in the North Pacific. Further and prolonged increases in ocean temperature could make Triangle Island, which contains the largest tufted puffin colony in Canada, unsuitable as a breeding site for this species.     

A hybrid form of myeloid/NK-cell acute leukemia and myeloid/NK-cell precursor acute leukemia

Natural killer (NK)-cell leukemia/lymphoma is a rare entity that has been defined only in recent years. In the Revised European-American Lymphoma and World Health Organization classifications, only the mature NK-cell malignancies are included. However, at least 3 types of precursor NK-cell neoplasms have been reported in the literature. These include myeloid/NK-cell acute leukemia, myeloid/NK-cell precursor acute leukemia, and blastic NK-cell lymphoma/leukemia. These leukemias are characterized by the presence of blasts, which express CD56, in the peripheral blood, bone marrow, lymph nodes, and/or extranodal tissues. We report a case that is morphologically consistent with myeloid/NK-cell acute leukemia but immunologically is myeloid/NK-cell precursor acute leukemia. This case is unique in its cutaneous presentation without involvement of the peripheral blood. Extensive flow cytometric studies were performed on the skin biopsy and bone marrow aspirate specimens, which included many markers that had not been tested before in these entities. The clinical implications of these findings are discussed.     

Assessment of Clostridium difficile Infections by Quantitative Detection of tcdB Toxin by Use of a Real-Time Cell Analysis System

We explored the use of a real-time cell analysis (RTCA) system for the assessment of Clostridium difficile toxins in human stool specimens by monitoring the dynamic responses of the HS27 cells to tcdB toxins. The C. difficile toxin caused cytotoxic effects on the cells, which resulted in a dose-dependent and time-dependent decrease in cell impedance. The RTCA assay possessed an analytical sensitivity of 0.2 ng/ml for C. difficile toxin B with no cross-reactions with other enterotoxins, nontoxigenic C. difficile, or other Clostridum species. Clinical validation was performed on 300 consecutively collected stool specimens from patients with suspected C. difficile infection (CDI). Each stool specimen was tested in parallel by a real-time PCR assay (PCR), a dual glutamate dehydrogenase and toxin A/B enzyme immunoassay (EIA), and the RTCA assay. In comparison to a reference standard in a combination of the three assays, the RTCA had a specificity of 99.6% and a sensitivity of 87.5% (28 of 32), which was higher than the EIA result (P = 0.005) but lower than the PCR result (P = 0.057). In addition, the RTCA assay allowed for quantification of toxin protein concentration in a given specimen. Among RTCA-positive specimens collected prior to treatment with metronidazole and/or vancomycin, a significant correlation between toxin protein concentrations and clinical CDI severities was observed (R² = 0.732, P = 0.0004). Toxin concentrations after treatment (0.89 ng/ml) were significantly lower than those prior to the treatment (15.68 ng/ml, Wilcoxon P = 0.01). The study demonstrates that the RTCA assay provides a functional tool for the potential assessment of C. difficile infections.Clostridium difficile is recognized as the leading cause of infectious diarrhea that develops in patients after hospitalization and/or in patients receiving antibiotic treatment (3, 12). Moreover, the recently emerged, highly virulent strain BI-NAP1-027 has been associated with increased morbidity and mortality (14, 16). A definitive diagnosis depends on the detection of C. difficile-specific toxin B production in the laboratory, which allows for prompt treatment and isolation procedures to prevent further nosocomial spread of infection (12, 19). There are a number of methods available that have been used for the laboratory diagnosis of C. difficile infection (CDI). The well-accepted standard is cytotoxigenic culture, which is conducted by culturing C. difficile from the stool and then performing a cytotoxin assay on the isolate (21). This standard is labor-intensive, subjective, and time-consuming and therefore is not widely used in the clinical setting. Several enzyme immunoassays (EIAs) detect C. difficile antigens in stool, including glutamate dehydrogenase (GDH), as well as toxins A and B (7, 19, 20, 22-24, 28, 29). PCR-based molecular assays that detect toxin A or B, or both, have shown promising performance (4, 10, 18, 24, 30).Currently, recommended therapies for CDI include oral administration of metronidazole and/or vancomycin for 10 to 14 days (6). However, increased percentages of patients experience infection relapse after completion of treatment (3, 12, 17). The emergence and spread of resistance in C. difficile are complicating treatment and prevention (9). While new antibiotics and therapeutic methods are available, providing a rapid and accurate laboratory tool for monitoring disease severity and therapy efficacy is clinically desirable. The C. difficile toxin assay, which detects cell toxicity caused by toxin B, is a direct determination of whether a functional C. difficile toxin exists in stool. However, this assay is labor- and time-intensive and provides only qualitative results.A real-time cell analysis (RTCA) assay (ACEA Biosciences, San Diego, CA) was developed for monitoring the cell status using electronic impedance technology. Utilizing a dimensionless parameter called the cell index (CI), the RTCA system detects the changes to the cell layers cultured on gold microelectrodes on the glass substrates integrated in the bottom of the microelectronic plates (25). This technology has been applied in a number of cell-based assays, including cytotoxicity, cell adhesion and spreading, functional monitoring of receptor-mediated signaling, and cell invasion and migration (2, 11, 31, 32). In this study, we adapt the system for assessment of C. difficile toxin directly from stool specimens. Analytical and diagnostic sensitivities and specificities of this system for the diagnosis and monitoring of CDI were determined. We also explored the assessment of clinical CDI severities and therapeutic efficacies by using toxin concentrations in stool specimens as determined by the RTCA assay.(This study was presented in part at the 110th American Society for Microbiology Annual Meeting, San Diego, CA, 23 to 27 May 2010.)