Varicella-Zoster Virus Reactivation and Increased Vascular Risk in People Living with HIV: Data from a Retrospective Cohort Study

BACKGROUND

The increased vascular risk associated with varicella-zoster virus (VZV) reactivation is extensively established in the general population. This retrospective cohort study investigates whether this observation holds for People Living with HIV (PLWH), a group already confronting heightened cardiovascular risk.

METHODS

Among PLWH who initiated antiretroviral therapy (ART) at our center and have been under our care for >24 months since 1st January 2005, individuals with a history of herpes zoster (HZ) were identified, and their features were compared with those of PLWH with no history of HZ. The prevalence of ischemic events (deep venous thrombosis, stroke, and acute myocardial infarction) was calculated and compared using the chi-square test. An odds ratio (O.R.) and a 95% confidence interval (C.I.) for ischemic events following HZ were evaluated through univariate and multivariate logistic regression.

RESULTS

Overall, 45/581 PLWH reported HZ. Ischemic events followed HZ significantly more often than not (13% vs. 5%, p = 0.01). Positive serology for both VZV and HZ correlated with increased ischemic risk (O.R. 4.01, 95% C.I. 1.38-11.6, p = 0.01 and O.R. 3.14, 95% C.I. 1.12-7.68, p = 0.02, respectively), though chronic heart disease demonstrated stronger predictive value in multivariate analysis(O.R. 8.68, 95% C.I. 2.49-29.50, p = 0.001).

CONCLUSIONS

VZV potentially exacerbates vascular risk in PLWH, particularly in the presence of other predisposing factors. Further research is needed to confirm our data.

Characterisation of Zea mays L. plastidial transglutaminase: interactions with thylakoid membrane proteins

Chloroplast transglutaminase (chlTGase) activity is considered to play a significant role in response to a light stimulus and photo-adaptation of plants, but its precise function in the chloroplast is unclear. The characterisation, at the proteomic level, of the chlTGase interaction with thylakoid proteins and demonstration of its association with photosystem II (PSII) protein complexes was accomplished with experiments using maize thylakoid protein extracts. By means of a specific antibody designed against the C-terminal sequence of the maize TGase gene product, different chlTGase forms were immunodetected in thylakoid membrane extracts from three different stages of maize chloroplast differentiation. These bands co-localised with those of lhcb 1, 2 and 3 antenna proteins. The most significant, a 58 kDa form present in mature chloroplasts, was characterised using biochemical and proteomic approaches. Sequential fractionation of thylakoid proteins from light-induced mature chloroplasts showed that the 58 kDa form was associated with the thylakoid membrane, behaving as a soluble or peripheral membrane protein. Two-dimensional gel electrophoresis discriminated, for the first time, the 58-kDa band in two different forms, probably corresponding to the two different TGase cDNAs previously cloned. Electrophoretic separation of thylakoid proteins in native gels, followed by LC-MS mass spectrometry identification of protein complexes indicated that maize chlTGase forms part of a specific PSII protein complex, which includes LHCII, ATPase and pSbS proteins. The results are discussed in relation to the interaction between these proteins and the suggested role of the enzyme in thylakoid membrane organisation and photoprotection.

Surface effects and desorption of tetracycline supramolecular complex on bovine dentine

The aim of this in vitro study was to evaluate the antimicrobial activity, the substantivity, and surface effects of the inclusion compound tetracycline: beta-cyclodextrin on bovine roots. The antimicrobial activity was assessed by dentine slabs which had been immersed in the inclusion complex in concentrations 8.0%, 4.0%, 2.0%, 1.0%, 0.5% and 0.25% for 5min compared to a control of tetracycline hydrochloride. Each slab was tested in a broth of overnight culture of Actinobacillus actinomycetemcomitans (Y4-FDC). The inclusion complex significantly inhibited the A. actinomycetemcomitans (p<0.01) verified at concentrations from 1.0% to 8.0%. The substantivity of tetracycline was evaluated by the measure of desorption from the slabs previously immersed in solution samples and removed at 24h intervals. The tetracycline encapsulated in beta-cyclodextrin showed a flow rate near to zero order in comparison to free tetracycline. The surface morphology determined by SEM showed a more homogeneous and integrated layer with the complex compared to the effect of free tetracycline. We concluded that the root surfaces treated with tetracycline: beta-cyclodextrin release lower concentrations of active drug over 5 days at inhibitory concentrations against A. actinomycetemcomitans with enhanced disponibility in comparison to tetracycline.

Coffee Leaf Scorch Caused by a Strain of Xylella fastidiosa from Citrus

Citrus variegated chlorosis (CVC) and coffee leaf scorch (CLS) are two economically important diseases in Brazil caused by the bacterium Xylella fastidiosa. Strains of the bacterium isolated from the two plant hosts are very closely related, and the two diseases share sharpshooter insect vectors. In order to determine if citrus strains of X. fastidiosa could infect coffee and induce CLS disease, plant inoculations were performed. Plants of coffee, Coffea arabica 'Mundo Novo', grafted on Coffea canephora var. robusta 'Apuatão 2258' were mechanically inoculated with triply cloned strains of X. fastidiosa isolated from diseased coffee and citrus. Three months postinoculation, 5 of the 10 plants inoculated with CLS-X. fastidiosa and 1 of the 10 plants inoculated with CVC-X. fastidiosa gave positive enzyme-linked immunosorbent assay (ELISA) and/or polymerase chain reaction (PCR). Eight months postinoculation, another six plants inoculated with CVC-X. fastidiosa gave positive PCR results. The two X. fastidiosa strains were isolated from the inoculated plants and showed the same characteristics as the original clones by microscopy, ELISA, and PCR. None of the plants inoculated with sterile periwinkle wilt (PW) medium as controls gave positive reactions in diagnostic tests, and none developed disease symptoms. Six months postinoculation, seven plants inoculated with CLS-X. fastidiosa and eight inoculated with CVC-X. fastidiosa began to develop characteristic CLS symptoms, including apical and marginal leaf scorch, defoliation, and reductions of internode length, leaf size, and plant height, terminal clusters of small chlorotic and deformed leaves, and lateral shoot dieback. We have demonstrated that X. fastidiosa from citrus plants is pathogenic for coffee plants. This has important consequences for the management of CLS disease and has implications for the origin of citrus variegated chlorosis disease.

Strains of Xylella fastidiosa rapidly distinguished by arbitrarily primed-PCR

Genomic DNAs isolated from strains of Xylella fastidiosa that caused citrus variegated chlorosis, coffee leaf scorch, Pierce's Disease of grapevine, and plum leaf scorch were analyzed by arbitrarily primed polymerase chain reaction. Purified DNA was amplified under nonstringent conditions with single primers 21 nucleotides (nt) long. Thirty-nine amplification products were observed that were useful to distinguish among the strains and to derive a similarity matrix and construct a phenogram showing possible relationships among the strains. Strains isolated from diseased coffee and citrus in Brazil were closely related to each other (coefficient of similarity of 0. 872), but only distantly related to a strain isolated from diseased grapevine in the USA (coefficient of similarity of 0.650). Strains of Xylella fastidiosa isolated from diseased plums in the USA and Brazil clustered with strains from different hosts isolated from their respective countries of origin. Thus, there may be two quite dissimilar clusters of strains of Xylella fastidiosa, one in North America and the other in South America. Each cluster contains strains that can cause disease in plum. The methods described provide a convenient and rapid method to distinguish between strains of Xylella fastidiosa that cause diseases of coffee and citrus in the same region of Brazil. This has not been possible previously. This will potentially enable the two strains to be distinguished in alternate hosts or in insect vectors.

Supraceliac clamping in the surgical treatment of abdominal aortic aneurysm. An experimental study in dogs

Previous reports have suggested the use of supraceliac aortic clamping in the surgical treatment of abdominal aortic aneurysm of difficult approach. The objective of the present report was to study the hepatic and renal metabolic changes of three groups of dogs submitted to temporary clamping (30 minutes) of the abdominal aorta at three different levels: below the renal arteries, infrarenal group (8 dogs); above the renal arteries, suprarenal group (9 dogs); above the celiac artery, supraceliac group (9 dogs). Blood bilirubin, alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea nitrogen, and creatinine levels were measured before clamping and 5 minutes and 24 hours after reperfusion of the aorta. Bilirubin levels remained unchanged 5 minutes and 24 hours after reperfusion in all three groups. Alkaline phosphatase levels were significantly increased in all three groups 24 hours after reperfusion. ALT levels increased significantly in the supraceliac group and AST levels increased significantly in the infrarenal and supraceliac groups 24 hours after reperfusion of the aorta. However, despite these significant increases after reperfusion, the levels of these hepatic enzymes were still within the normal range for dogs. Urea nitrogen and creatinine levels showed that renal function did not change in any of the three groups. We conclude that supraceliac, infrarenal or suprarenal aortic clamping for 30 minutes do not promote any important changes in the hepatic or renal function of dogs.

Epidemiological aspects of acute viral hepatitis in São Paulo, Brazil

As few reports on the prevalence of each type of viral hepatitis have been published in our country, we studied 154 patients with acute viral hepatitis consecutively seen at the Liver Unit from November 1980 to November 1984. The frequency of hepatitis A, B and non-A, non-B was 52.6%, 27.3% and 20.1% respectively. Greater frequency in young people, previous contact with infected patients and ingestion of suspected foods were the predominant epidemiological features in the hepatitis A group. Hepatitis B was characterized by the parenteral, non-transfusional exposure, previous contact and a high occurence in health-care workers. A history of blood transfusion was a significant finding in the hepatitis non-A, non-B group. Finally, the routes of transmission were unknown in 30-40% of the three groups of patients.