The rapid and extensive spread of the human immunodeficiency virus (HIV) epidemic provides a rare opportunity to witness host-pathogen co-evolution involving humans. A focal point is the interaction between genes encoding human leukocyte antigen (HLA) and those encoding HIV proteins. HLA molecules present fragments (epitopes) of HIV proteins on the surface of infected cells to enable immune recognition and killing by CD8(+) T cells; particular HLA molecules, such as HLA-B*57, HLA-B*27 and HLA-B*51, are more likely to mediate successful control of HIV infection. Mutation within these epitopes can allow viral escape from CD8(+) T-cell recognition. Here we analysed viral sequences and HLA alleles from >2,800 subjects, drawn from 9 distinct study cohorts spanning 5 continents. Initial analysis of the HLA-B*51-restricted epitope, TAFTIPSI (reverse transcriptase residues 128-135), showed a strong correlation between the frequency of the escape mutation I135X and HLA-B*51 prevalence in the 9 study cohorts (P = 0.0001). Extending these analyses to incorporate other well-defined CD8(+) T-cell epitopes, including those restricted by HLA-B*57 and HLA-B*27, showed that the frequency of these epitope variants (n = 14) was consistently correlated with the prevalence of the restricting HLA allele in the different cohorts (together, P < 0.0001), demonstrating strong evidence of HIV adaptation to HLA at a population level. This process of viral adaptation may dismantle the well-established HLA associations with control of HIV infection that are linked to the availability of key epitopes, and highlights the challenge for a vaccine to keep pace with the changing immunological landscape presented by HIV.

OBJECTIVES: To estimate the prevalence of urogenital infection with Chlamydia trachomatis and Neisseria gonorrhoeae in persons 18 to 35 years of age in Barbados, and to examine factors associated with infection. METHODS: Cross-sectional survey of randomly selected persons from the voters' register of one electoral district, with the collection of urine samples for testing by polymerase chain reaction. RESULTS: The response rate was 82%, with 408 persons (195 males and 213 females) having questionnaires completed and urine collected. 397 urine samples were satisfactorily tested. Prevalence of C. trachomatis (CT) and N. gonorrhoeae (NG) urogenital infection was 11.3%(95% confidence interval [CI]+2.9), and 1.8%(95%CI +1.2) respectively, with 12.6%(95%CI +3.1) having either or both infections. The difference in prevalence by gender was not significant. Multivariate logistic regression showed that prevalence of CT and/or NG decreased with increasing age (per year odds ratio [OR] 0.89, 95%CI 0.84-0.96, p=0.001), and decreasing time (<6 months vs.>6months) since last medical consultation (OR 0.44, 95%CI 0.22-0.88, p=0.02). Most (76%) infected persons were asymptomatic. Condom use at last intercourse with a partner not being lived with was (reported by 52%) was not protective (p=0.617). The usual source of health care was evenly distributed between the public and private sectors and was not associated with infection. Only 30% of persons had ever heard of chlamydia, while 92% were aware of gonorrhoea. CONCLUSIONS: Asymptomatic infection with C. trachomatis is an important reservoir of infection, which will remain undetected unless physicians and young persons are aware of this, and screening is introduced.

OBJECTIVE:: To compare the Panleucogating (PLG) protocol with the routinely used four-color protocol for CD4(+) T cell count enumeration. DESIGN AND METHODS:: One hundred fifty-three blood samples were randomly selected from samples received at the National HIV Laboratory for routine immunological monitoring. Samples were prepared using Coulter CYTO-STAT(R) tetraCHROME monoclonal antibodies and FlowCAREtrade mark PLG CD4 reagent for four-color and PLG, respectively, and analyzed on the Beckman Coulter EPICS XL flow cytometer. The PLG protocol used a sequential gating strategy where CD4(+) T cells were identified using side scatter properties of cells and CD45 staining. The four-color protocol used CD45 and CD3 to identify CD4(+) T cells. RESULTS:: Absolute CD4(+) T cell counts and percentages ranged from 4 to 1,285 cells/muL and 0.9 to 46.7%, respectively. Linear regression analyses revealed good correlation of PLG with the four-color protocol (absolute counts, R(2)= 0.95; percentages, R(2)= 0.98) over the entire range including the clinically relevant range. Bland Altman statistics revealed no bias for CD4 counts <500 cells/muL and a slight underestimation by PLG for counts >500 cells/muL (Bias =-32.7 cells/muL; 95% agreement limits =-151.3-+86.0). CD4(+) T cell percentages were the similar over the entire range (Bias = 0.6%; 95% agreement limits =-1.97 +/- 3.18). CONCLUSIONS:: PLG is an accurate method for enumerating CD4(+) T cells and has resulted in major cost savings to the Government of Barbados. This has implications for the sustainability of the National HIV containment program in Barbados and the other resource limited Caribbean countries. The PLG technique is now being routinely used in Barbados.(c) 2008 Clinical Cytometry SocietyHow to cite this article: Sippy-Chatrani N, Marshall S, Branch S, Carmichael-Simmons K, Clive Landis R, Abayomi A. Performance of the Panleucogating Protocol for CD4(+) T Cell Enumeration in an HIV Dedicated Laboratory Facility in Barbados. Cytometry Part B 2008; 74B (Suppl.): 000-000.

The Caribbean relies on normal lymphocyte subsets ranges established in other geographical locations and from different racial ethnic groups for the basis of the clinical management of HIV and AIDS with Highly Active Anti Retroviral Therapy (HAART). Normal ranges of these parameters have not been previously established in an Afro-Caribbean population. So we set out to determine how the normal lymphocyte subset ranges compare to those reported in other, races and geographical locations. A prospective study was done on 112 healthy Afro-Caribbean clients who attended the Blood Collection Unit, Queen Elizabeth Hospital, Barbados from July 15th to November 12th 2004. Analysis for lymphocyte subsets was done by flow cytometry, which allows simultaneous identification and enumeration of total T Helper, cytotoxic T, natural killer and B lymphocyte cells. HIV-1, Hepatitis B and C, HTLV-1 and full blood count test were done as part of the normal screening routine of all blood donors. Absolute white blood cell counts and percentage lymphocytes for males and females were not significantly different, and the absolute and percentage of the T-Helper CD4 positive lymphocyte cells were not significantly higher in females than in males. Absolute Cytotoxic T cell CD8 positive lymphocyte cells were higher in males than in females. CD56 Natural Killer cells absolute and percentage counts were higher in males than females however CD19 B Lympocyte absolute and percentage counts were not different between the two sexes in this sample population. Compared to published normal ranges published by the WHO and CDC, there were no significantly differences observed in any of the lymphocyte subsets. These finding are very similar to what has been reported in previous studies. We conclude that WHO/CDC recommendations established for the treatment and monitoring of HIV/AIDS patients based on CD4 levels can be safely utilized in our population.

Posner-Schlossman syndrome is a rare eye condition involving mild anterior chamber inflammation and extreme intermittent intraocular pressure elevations. Symptoms are mild and not incapacitating, but aviators need proper diagnosis and treatment to ensure that visual acuity and visual fields are not affected.

The (1)H NMR characteristics of the majority of penicillin and cephalosporin beta-lactam antibiotics in world-wide clinical use are presented. Some of the data are novel and include several high resolution (220, 400 MHz) spectra. The influence of solvent and ionisation state upon spectral parameters is discussed and a scheme of analysis proposed for identifying an unknown beta-lactam sample. Spectral features of common degradation products of benzylpenicillin and other penicillins are provided and the use of (1)H NMR spectroscopy in monitoring the breakdown of penicillin antibiotics described. Other aspects discussed are NMR studies of the stereochemistry, association and protein binding of beta-lactam antibiotics.

Leptospirosis is a febrile zoonosis of worldwide distribution. A latex agglutination assay was evaluated in two studies, the first using a panel of well-characterized sera from patients with leptospirosis and from patients with other disease states and the second, a prospective hospital-based study, evaluating sera from 186 consecutive patients admitted to hospital with acute febrile illness. The confirmed leptospirosis serum panel included paired acute- and convalescent-phase specimens from 40 cases, of which 34 gave positive latex tests (case sensitivity, 85%; 95% confidence interval [95% CI], 70 to 94%). The other diseases represented in the panel of 112 specimens from nonleptospirosis patients included autoimmune diseases, brucellosis, dengue, melioidosis, malaria, syphilis, toxoplasmosis, viral hepatitis, and a number of other viral infections. The specificity of latex agglutination using this panel was 81%(95% CI, 73 to 87%). Among the patients with acute febrile illness, there were 25 cases of leptospirosis and 161 patients with other diagnoses. The sensitivity and specificity of latex agglutination in this group were 88%(95% CI, 72 to 97%) and 98%(95% CI, 95 to 100%), respectively. In this evaluation, the two distinct groups of specimens gave similar results for sensitivity, but specificity was different in each study. The sensitivity and specificity observed for the hospital study were similar to those obtained in evaluations of other rapid tests in the same population. The results of this study suggest that multiple evaluations of new diagnostic assays should be performed, because performance characteristics may vary in different populations.

5-Aza-2'-deoxycytidine (d-AZA) causes temporally-related defects in the mouse. At 1.0 mg/kg on gestational day (GD) 10, d-AZA causes hindlimb phocomelia. Sonic hedgehog (Shh) plays a significant role in the normal development of limbs in rodent species. Sonic hedgehog peptides, found in the posterior mesenchyme of limb buds, are involved in patterning functions and in the regulation of both anterior-posterior polarity and proximal-distal outgrowth of the limb. The objective of the present study was to analyze alterations in Shh expression subsequent to d-AZA exposure. Pregnant mice were treated with d-AZA via intraperitonlal injection on GD 10. Controls were untreated. The reverse transcription-polymerase chain reaction (RT-PCR), whole mount in situ hybridization (ISH), and whole mount immunohistochemistry (WMI) were used to analyze expression patterns of Shh . For RT-PCR, embryonic hindlimb buds (buds) were taken 0, 4, 8, 12, or 24 hr after exposure. Cyclophilin was used as the baseline monitor. RNA was transcribed to cDNA and used as template with Shh specific primers for amplification. Whole embryos were collected 12 and 24 hr posttreatment for ISH. An antisense primer specific for Shh was used in an oligo-based ISH protocol. Whole embryos were collected 36 and 48 hr posttreatment for WMI. The antibody corresponding to the amino terminal subunit of the Shh peptide was used. There was a treatment related up-regulation of Shh transcripts by 12 and 24 hr posttreatment. The protein response of up-regulation was detectable by 36 and 48 hr posttreatment. Our data suggest that 5-aza-2'-deoxycytidine-induced hindlimb defects may be associated with alterations in the level of Shh expression. This may be part of a cascade of signaling events involved in d-AZA-induced hindlimb defects. Work is ongoing to determine the relationship of other gene species that may cooperate with Shh in the induction of the hindlimb defects.

This article describes the development of international guidance on registration of technical dossiers supporting applications to market medicinal products. Aspects of guidance of particular relevance to the use of NMR spectroscopy in drug development and control are discussed.

CONTEXT: Pancreatic stents may be placed during therapeutic ERCP for a variety of indications. One such indication is to prophylax against the development of pancreatitis following sphincterotomy of the minor papilla in patients with recurrent acute pancreatitis and pancreas divisum. Increasingly, endoscopists that perform pancreatic ERCP are placing small caliber (3 Fr), unflanged, single pigtail stents into the long axis of the pancreatic duct with the expectation that these stents will only stay in place for a few days and the majority will pass spontaneously on their own without the need for follow-up endoscopic retrieval. As such, these stents are generally regarded as safer and associated with a lower rare of complication than larger (5 and 7 Fr), double flanged pancreatic stents. CASE REPORT: We present the case of a 3 Fr stent that migrated proximally into the dorsal duct in a patient with recurrent pancreatitis and pancreas divisum. Due to the small size of the patient's dorsal duct, it was difficult to pass appliances alongside the stent to facilitate retrieval and a variety of appliances were used before success was achieved. DISCUSSION: The medical literature contains series of proximally migrated larger caliber flanged, pancreatic stents but proximal migration of small caliber, unflanged, pigtail stents has not yet been reported. As the use of these small stents increases, we feel that it is important to highlight the potential for this complication and discuss how we successfully treated our patient.