Clinical implications of local impedance measurement using the IntellaNav MiFi OI ablation catheter: an ex vivo study

Journal of Interventional Cardiac Electrophysiology - Clinical implication of local impedance (LI) for radiofrequency (RF) ablation has not been fully established. This study aimed to investigate...     

A single multiplex assay to identify major malaria vectors within the African Anopheles funestus and the Oriental An. minimus groups

The African Anopheles funestus and the Oriental An. minimus groups are closely related and composed of major malaria vectors in Africa and Southeast Asia, respectively. None of the species of either the An. funestus or the An. minimus group can be identified with absolute certainty using the adult morphology. Polymorphisms present on the internal transcribed spacer 2 (ITS2) of ribosomal DNA allowed the development of 10 primers that combined with an universal forward primer lead to a simple and sensitive multiplex allele-specific polymerase chain reaction (AS-PCR). Moreover, the possible additional amplification of the entire ITS2 allows one to detect other anopheline species in sympatry with members of both groups not included in this assay and serves as a control band. This universal PCR method permits the discrimination of 10 species within the subgenus Cellia, among which figure three major malaria vectors, and constitutes a very efficient and powerful tool to improve our knowledge on these species distribution and biology. Not only restricted to anophelines, this AS-PCR could also be developed and applied to other insect groups.     

Age related changes in the pituitary-testicular axis in normal men; lower serum testosterone results from decreased bioactive LH drive

OBJECTIVE The mechanism underlying the slight hypoandrogenism associated with normal ageing remains unclear. We have therefore examined age related changes in the activity of the pituitary-testicular axis In healthy normal males. DESIGN Random blood samples were obtained from 219 normal men whose ages ranged from 20 to 79 years. At the time of the study, none of the men had received treatment or had ever had any endocrine dysfunction diagnosed. MEASUREMENTS Luteinizing hormone was measured In the subjects' plasma using a commercially available immunoradiometric assay (IRMA, Serono Malaclone) and a fully validated In-vitro bioassay. Testosterone and FSH were measured using standard radioimmunoassays (RIA) whilst sex hormone binding globulin was assayed by an IRMA. RESULTS Levels of total testosterone (total-T) and bioactive LH fell with age (r=?0.231 and ?0.189 respectively) by 5.9nmol/l and 2.3IU/I respectively between grouped patients aged 20-39 years (Group A) and 60–79 years (Group C). In contrast, immunoreactlve LH remained unchanged. The LH B:I ratio also fell with age (P<0.0001) being 5.0±0.3 (group A) and 3.3±0.2 (group C), representing a fall of 33%. Since Immunoreactivlty remained constant, this fall primarily represented the decline in LH bioactivity. Bioactive, but not immunoreactlve LH correlated to total-T (P=0.009, n=209) and the total-T:LH ratios fell by over 30% between groups A and C using the IRMA, but remained unchanged by bioassay. CONCLUSIONS There Is an underlying decline In both total-testosterone and free-testosterone index, and bioactive LH levels with advancing age, suggestive of a hypothalamo-pituitary defect which leads to lower bioactive LH levels which in turn are responsible for the diminished gonadal steroidogenesis. Elucidation of the mechanism underlying this slight decline in hypothalamo-pituitary testicular activity Is complicated by differences between the data obtained by immunoassay or bioassay.     

The molecular epidemiology of HIV type 1 among Vietnamese Australian injecting drug users in Melbourne, Australia

The proportion of human immunodeficiency virus type 1 (HIV-1) among Vietnamese injecting drug users (IDUs) in Melbourne, Australia exceeds that of the background population. To investigate the molecular epidemiology of HIV-1 among this group, the C2-V4 region of the HIV-1 envelope was directly sequenced from 11 Vietnamese Australians and 19 non-Vietnamese Australian controls. A significant difference in the distribution of the HIV-1 subtypes was demonstrated, with greater than 50% of Vietnamese Australian IDU shown to be infected with CRF01_AE-the predominant subtype in Southeast Asia, rather than subtype B, which dominates the Australian epidemic and which was found in 89.5% of the non-Vietnamese controls. The genetic diversity of the CRF01_AE epidemic in Vietnamese Australian IDUs was substantially lower that that of the background subtype B, consistent with a more recent introduction of a limited number of viral strains from Vietnam. These results support public health policy targeting Australian IDUs of Vietnamese ethnicity as a distinct vulnerable population.     

A proof-of-concept study of short-cycle intermittent antiretroviral therapy with a once-daily regimen of didanosine, lamivudine, and efavirenz for the treatment of chronic HIV infection

BACKGROUND: We previously demonstrated that short-cycle structured intermittent therapy (SIT; 7 days without therapy followed by 7 days with antiretroviral therapy [ART]) with a ritonavir-boosted, indinavir-based, twice-daily regimen maintained suppression of plasma HIV viremia while reducing serum levels of lipids. Adherence to such a regimen may be problematic for certain patients. METHODS: Eight patients with a history of receiving combination ART that maintained suppression of plasma HIV RNA to <50 copies/mL received a once-daily SIT regimen of didanosine, lamivudine, and efavirenz. RESULTS: For 7 patients, suppression of plasma HIV RNA to <50 copies/mL was maintained for 60-84 weeks. Four patients with adequate samples had no evidence for an increase in plasma viremia for up to 72 weeks, by use of an assay with a limit of detection of <1 copy/mL. The lack of rebound viremia may be the result of the persistence of efavirenz in plasma on day 7 of the no-therapy period, as was detected in 7 of 7 patients. There was no significant change in CD4(+) T cell counts or serum hepatic transaminase or lipid levels. CONCLUSION: A once-daily short-cycle SIT regimen maintained suppression of plasma HIV RNA while preserving CD4(+) T cell counts. Such a regimen may have importance in resource-limited settings where the monetary cost of continuous ART is prohibitive.     

Toward the development of a test for growth hormone (GH) abuse: a study of extreme physiological ranges of GH-dependent markers in 813 elite athletes in the postcompetition setting

There is a need to develop a test to detect GH abuse by elite athletes. Measured levels of GH in blood or urine, however, provide little information on the GH-IGF-I axis. Previous studies have identified a series of indirect markers of GH action that are markedly altered by the administration of GH, but to a lesser degree by acute exercise. This study was undertaken to determine the physiological range of these GH-dependent variables in elite athletes after a competitive event to determine whether such values differ from resting values in normal and athletic subjects and to establish whether any adjustments to this range are required on the basis of age, gender, demographic characteristics, or the nature of the exercise performed. Serum samples were collected from 813 elite athletes (537 males and 276 females; age range, 17-64 yr) from 15 sporting disciplines within 2 h of completion of a major competitive event. IGF-I, IGF-binding protein 2 (IGFBP-2), IGFBP-3, acid-labile subunit, and the bone and soft tissue markers, osteocalcin, carboxyl-terminal propeptide of type I procollagen, carboxyl-terminal cross-linked telopeptide of type I collagen, and procollagen type III were measured. Sporting category, gender, age, height, weight, body mass index (BMI), and racial group of the athlete were documented, and results were compared both to normative data and to values obtained from elite athletes under resting conditions. Forty-one percent of IGF-I values in male athletes and 41% of values in female athletes were above the upper limits of 99% reference ranges derived from resting values in a normal population. Postcompetition levels of all variables except carboxyl-terminal propeptide of type I procollagen and carboxyl-terminal cross-linked telopeptide of type I collagen differed from resting values. There was a consistent age-dependent fall in measured levels of all variables (P < 0.0001) with the exception of IGFBP-2, which increased with age (P < 0.0001). BMI, but not height, exerted a small, but significant, influence on several variables. After adjustment for age, there were no significant differences in the levels of any of the measured variables between sporting categories. IGFBP-2 and IGFBP-3 were lower in 35 black athletes compared with those in 35 white athletes matched for age, gender, height, BMI, and sporting category. We have demonstrated that there are predictable age-dependent levels of GH-dependent markers in elite athletes that are consistent even at the extremes of physical exertion and that these are independent of sporting category. Normative data applicable to white athletes are provided. This provides important groundwork for the development of a test for GH abuse, although these values may be specific for the reagents and assays used.     

Coagulation disorders in patients with cirrhosis and severe sepsis

Background: In patients with cirrhosis, severe sepsis may stimulate the extrinsic coagulation pathway resulting in thrombin generation and fibrin formation. Aims: To compare 23 patients with severe sepsis to 13 infected patients without severe sepsis and 18 patients without infection. Methods: Zymogen forms of clotting factors involved in the extrinsic pathway (i.e., factors VII+X, V, prothrombin), and the presence of soluble fibrin were assessed. Results: Zymogen forms of clotting factors were significantly lower, while Child–Pugh score and the proportion of patients with soluble fibrin were higher in the severe‐sepsis group than in the other groups. Decreased zymogen levels were independently correlated with an elevated Child–Pugh score and the presence of severe sepsis. In the severe‐sepsis group, after adjustment for the severity of cirrhosis, decreased zymogen levels were associated with significant increases in the relative risk ratios of in‐hospital death. Conclusions: Cirrhotic patients with severe sepsis have decreased blood levels of zymogen forms of factors VII+X, V, and prothrombin, which may be due not only to the severity of cirrhosis but also, at least in part, to the consumption of these zymogens by the extrinsic coagulation pathway.