Neurological complications in AIDS patients: the 1-year retrospective study in Chiang Mai University, Thailand

The first case of AIDS patient in the northern part of Thailand was reported in 1987 (Vithayasai et al., 1996), marking the outbreak of an epidemic. In our experience, the neurological involvement in AIDS patients seems to have changed in pattern and incidence during the last 8 years. We have conducted a retrospective study to review the incidence of AIDS-defining diseases in the patients admitted to Chiang Mai University Hospital, Thailand during the period September 2001 to August 2002. There were 155 AIDS patients admitted during this specified period, 118 of which were male and 37 female, aged between 16 and 60. The incidence of neurological complications was 50.3 per 100 person-years, in which central nervous system involvement account for 46.5 per 100 person-years and peripheral nervous system involvement account for 3.8 per 100 person-years. The incidence of cryptococcal meningitis appeared to be decreasing since 1994 whereas the incidence of cerebral toxoplasmosis appeared to be increasing. The incidence of cryptococcal meningitis, cerebral toxoplasmosis and cytomegalovirus (CMV) infection was 18.0, 14.8 and 7.0 per 100 person-years, respectively. Other common non-neurological AIDS-defining illnesses in northern Thailand include pulmonary tuberculosis (15.4 per 100 person-years), extra-pulmonary tuberculosis (9.6 per 100 person-years), and disseminated penicilliosis (12.2 per 100 person-years). In this way and summarizing, in northern Thailand, the three most common neurological involvements before the era of highly active anti-retroviral therapy are cryptococcal meningitis, cerebral toxoplasmosis and CMV infection. The incidence of cryptococcal meningitis appeared to be decreasing whereas the incidence of cerebral toxoplasmosis seemed to be increasing.     

A convenient immunochromatographic test strip for rapid diagnosis of yellow head virus infection in shrimp

A simple yellow head virus (YHV) “strip test” was developed using monoclonal antibody Y19 (against the p20 structural protein) conjugated with colloidal gold as the detector antibody. Rabbit anti-recombinant p20 (rp20) protein antibody was used as a capture antibody at the test line (T) and goat anti-mouse IgG antibody (GAM) was used as the capture antibody at the control line (C). The ready-to-use strip was housed in a plastic case for convenient application and stored in the desiccated plastic bag. A sample volume of 100 μl of either haemolymph or gill or appendage homogenates in application buffer was applied to the sample chamber at one end of the strip and allowed to flow by chromatography through the nitrocellulose membrane to the other end. In test samples containing YHV, the virus would bind to colloidal gold conjugated monoclonal antibody and the resulting complex would be captured by the rabbit anti-rp20 antibody at the test line to give a reddish-purple band. Any unbound monoclonal antibody conjugated with colloidal gold moved across the test line to be captured by the GAM to form a band at the control line (C). In the sample without YHV or below the limit of detection for the kit, only the control line was demonstrated. This method was about 500 times less sensitive than that of one-step RT-PCR, but slightly more sensitive than dot blotting. Therefore, it could be used for primary screening of individual shrimp or pooled shrimp samples to confirm high levels of YHV infection or YHV disease outbreaks. This kit can be used to detect gill associated virus (GAV) infection as well since the monoclonal antibody used in this kit cross-reacted well with GAV. The beneficial features of this kit are that simple, convenient, and rapid results that can be obtained without the requirement of sophisticated tools or special skills.     

Effects of an n-butanol extract from the stem of Tinospora crispa on blood pressure and heart rate in anesthetized rats

Ethnopharmacological relevance

Tinospora crispa has been used in folkloric medicine for control of blood pressure, as an antipyretic, for cooling down the body temperature and for maintaining good health.

Aim of the study

To investigate the effects and mechanisms of action of an n-butanol extract from the stems of Tinospora crispa (T. crispa extract) on blood pressure and heart rate in anesthetized rats.

Materials and methods

Air-dried stems of T. crispa were extracted with water, followed by partitioned extract with chloroform, ethyl acetate, and finally by n-butanol. The n-butanol soluble part was evaporated under reduced pressure and lyophilization to obtain a crude dried powder (T. crispa extract). The effects and mechanisms of the T. crispa extract on blood pressure and heart rate were studied in anesthetized normal and reserpinized rats in vivo in the presence of different antagonists.

Results

T. crispa extract (1-100 mg/kg, i.v.) caused a decrease in mean arterial blood pressure (MAP) and this effect was inhibited by propranolol, phentolamine, atenolol and/or the β₂-antagonist ICI-118,551, but not by atropine or hexamethonium. In reserpinized rats, the T. crispa extract had a dual effect: reduction in hypotensive activity, followed by a small increase in blood pressure. The decrease in MAP in reserpinized rat was slightly potentiated by phentolamine, but inhibited by propranolol or ICI-118,551 only if atenolol and phentolamine were also present. The increase in MAP was potentiated by propranolol and ICI-118,551, but was inhibited by phentolamine. The T. crispa extract had a dual effect on heart rate in the normal rat: a small transient decrease, followed by an increase in heart rate. The positive chronotropic effect of T. crispa extract was inhibited by propranolol, phentolamine and atenolol, but not by ICI-118,551, atropine or hexamethonium. Reserpine potentiated the positive chronotropic effect of the T. crispa extract and this effect was inhibited by propranolol, atenolol and ICI-118,551, but not by phentolamine.

Conclusions

From these results we suggest that T. crispa extract possesses at least three different cardiovascular-active components that act directly via (1) β₂-adrenergic receptors to cause a decrease in blood pressure, and β₁- and β₂-adrenergic receptors to cause an increase in heart rate, (2) α-adrenergic receptors to cause an increase in blood pressure and heart rate, and (3) a non-adrenergic and non-cholinergic pathway to cause a decrease in MAP and heart rate. These findings provide scientific support for the tradition of using this plant to modify the actions of the human cardiovascular system.     

Neurological complications in AIDS patients receiving HAART: a 2-year retrospective study

The positive role of highly active anti-retroviral therapy (HAART) in reducing opportunistic infections in acquired immunodeficiency syndrome (AIDS) patients is well known. However, case reports from around the world have demonstrated that some patients seem to suffer a paradoxical deterioration of health as their immune function improves with treatment. This phenomenon has been called immune restoration inflammatory syndrome (IRIS). In northern Thailand, GPO-vir (Stavudine-D4T + Lamivudine-3TC + Nevirapine-NVP) has been promoted for the treatment of AIDS patients since April 2002, in accordance with the Government Pharmaceutical Organization's guidelines. However, the incidence rates of IRIS affecting nervous system (NIRIS) and non-NIRIS in comparison with the previous incidence of AIDS-defining disease have not been reported. We conducted a retrospective study to review the incidence of NIRIS and non-NIRIS in AIDS patients treated with GPO-vir in Chiang Mai University Hospital, Thailand, between May 2002 and April 2004. We compare these incidence rates with the incidence rates of neurological complications in the pre-HAART era. Altogether 506 AIDS patients were treated with GPO-vir during the specified period. The overall incidence of NIRIS, including progressive multifocal leukoencephalopathy (PML), cerebral toxoplasmosis and cytomegalovirus (CMV) retinitis, was lower than the previous incidence of AIDS-defining disease in the pre-HAART era. However, the incidence of ischemic stroke, hemorrhagic stroke and primary central nervous system (CNS) lymphoma had increased.     

Penaeus monodon nucleopolyhedrovirus detection using an immunochromatographic strip test

An immunochromatographic strip test is described for detection of the polyhedrin protein of Penaeus monodon nucleopolyhedrovirus (PemoNPV). The test employs one monoclonal antibody (MAb MBV5) conjugated to colloidal gold to bind to polyhedrin protein and a 1:1:1 mixture of 3 other MAbs (MBV8, 14 and 21) to capture colloidal-gold MAb-protein complexes at a test (T) line on the nitrocellulose strip. A downstream control (C) line of goat anti-mouse immunoglobulin G (GAM) antibody is used to capture excess free colloidal-gold conjugated MBV5 to validate test performance. Heating of homogenates of PemoNPV-infected P. monodon postlarvae prepared in PBS for 30min was necessary to maximize T line color intensity, and homogenates of infected postlarvae could still be scored as PemoNPV-positive when diluted 1:64. A strip test result was obtained within 15min of sample application, and although about 200-fold lower than a one-step PCR test for PemoNPV, its detection sensitivity was comparable to a dot blot. Due to its simplicity not reliant on sophisticated equipment or specialized skills, the strip test could be adopted to screen easily for PemoNPV infections at shrimp hatcheries and farms.     

Molecular isolation and characterization of a novel occlusion body protein gene from Penaeus monodon nucleopolyhedrovirus

The full-length of the occlusion body (OB) protein gene of Penaeus monodon nucleopolyhedrovirus (PemoNPV) was successfully isolated. The OB gene sequence contained an open reading frame (ORF) of 1359 nucleotides encoding a protein of 452 amino acid residues with a predicted molecular mass of 50.6 kDa. A putative late promoter element, TAAG, was identified 72 nt upstream of the translation start site. The amino acid sequences of tryptic digested peptides of PemoNPV OB protein obtained from LC-MS analysis matched quite well with various regions of deduced amino acid sequences. Recombinant PemoNPV OB proteins specifically reacted with monoclonal antibodies to PemoNPV OB protein. After comparison with nucleotide database, the PemoNPV OB ORF demonstrated 67% identity to an uncharacterized ORF of a baculovirus pathogenic for Penaeus vannamei. However, comparison against protein databases revealed no significant homology to other known proteins.To our knowledge, this PemoNPV OB gene is the first isolated and characterized gene of nucleopolyhedrovirus from shrimp.     

Performance of the CRAFTi portable fluorometer comparing with the HPLC method for determining serum retinol

Objective

To determine the performance of a portable fluorometer for measuring serum retinol (SR) concentration.

Design and methods

Serum samples were obtained from 75 factory worker women and 143 school children. SR concentration was quantified using a portable fluorometer (‘CRAFTi’) and HPLC analysis.

Results

SR by HPLC (1.23 ± 0.43 μmol/L) and CRAFTi (1.16 ± 0.46 μmol/L) was significantly correlated. Sensitivity and specificity were 85.3% and 78.0% (cutoff of 1.05 μmol/L). Kappa statistics showed moderate agreement.

Conclusions

CRAFTi portable fluorometer is a promising field-friendly tool for screening vitamin A deficiency.     

Immunological-based assays for specific detection of shrimp viruses

Among shrimp viral pathogens, white spot syndrome virus (WSSV) and yellow head virus (YHV) are the most lethal agents, causing serious problems for both the whiteleg shrimp, Penaeus (Litopenaeus) vannamei, and the black tiger shrimp, Penaeus (Penaeus) monodon. Another important virus that infects P. vannamei is infectious myonecrosis virus (IMNV), which induces the white discoloration of affected muscle. In the cases of taura syndrome virus and Penaeus stylirostris densovirus (PstDNV; formerly known as infectious hypodermal and hematopoietic necrosis virus), their impacts were greatly diminished after the introduction of tolerant stocks of P. vannamei. Less important viruses are Penaeus monodon densovirus (PmDNV; formerly called hepatopancreatic parvovirus), and Penaeus monodon nucleopolyhedrovirus (PemoNPV; previously called monodon baculovirus). For freshwater prawn, Macrobrachium rosenbergii nodavirus and extra small virus are considered important viral pathogens. Monoclonal antibodies (MAbs) specific to the shrimp viruses described above have been generated and used as an alternative tool in various immunoassays such as enzyme-linked immunosorbent assay, dot blotting, Western blotting and immunohistochemistry. Some of these MAbs were further developed into immunochromatographic strip tests for the detection of WSSV, YHV, IMNV and PemoNPV and into a dual strip test for the simultaneous detection of WSSV/YHV. The strip test has the advantages of speed, as the result can be obtained within 15 min, and simplicity, as laboratory equipment and specialized skills are not required. Therefore, strip tests can be used by shrimp farmers for the pond-side monitoring of viral infection.     

Disclosure challenges among people living with HIV in Thailand

One of the main challenges facing people living with HIV (PLH) in Thailand is HIV disclosure. The goal of this study was to examine HIV disclosure barriers and motivators in Northeastern Thailand. Focus groups were conducted with 40 PLH to explore the barriers and motivators. To confirm the themes identified in the focus groups, face‐face interviews were conducted with 50 PLH. Focus group findings revealed barriers to HIV disclosure in three domains: perceived stigma, shame and fear of rejection. Motivators to HIV disclosure consisted of the following: coping with illness, seeking help and common experiences. Findings from the face‐to‐face interviews included the following barriers: fear of privacy breach, fear of rejection and communication difficulties. The motivators to HIV disclosure included seeking supportive relationship, duty to inform and catharsis. Based on these findings, we are currently developing family‐focused HIV disclosure intervention in Northeastern Thailand.