Sampling Males Who Inject Drugs in Haiphong,Vietnam: Comparison of Time-Location and Respondent-Driven Sampling Methods

Accurate measurements of HIV prevalence and associated risk factors among hidden and high-risk groups are vital for program planning and implementation. However, only two sampling methods are purported to provide representative estimates for populations without sampling frames: time-location sampling (TLS) and respondent-driven sampling (RDS). Each method is subject to potential biases and questionable reliability. In this paper, we evaluate surveys designed to estimate HIV prevalence and associated risk factors among people who inject drugs (PWID) sampled through TLS versus RDS. In 2012, males aged ≥16 years who reported injecting drugs in the previous month and living in Haiphong, Vietnam, were sampled using TLS or RDS. Data from each survey were analyzed to compare HIV prevalence, related risk factors, socio-demographic characteristics, refusal estimates, and time and expenditures for field implementation. TLS (n = 432) and RDS (n = 415) produced similarly high estimates for HIV prevalence. Significantly lower proportions of PWID sampled through RDS received methadone treatment or met an outreach worker. Refusal estimates were lower for TLS than for RDS. Total expenditures per sample collected and number of person-days of staff effort were higher for TLS than for RDS. Both survey methods were successful in recruiting a diverse sample of PWID in Haiphong. In Vietnam, surveys of PWID are conducted throughout the country; although the refusal estimate was calculated to be much higher for RDS than TLS, RDS in Haiphong appeared to sample PWID with less exposure to services and required fewer financial and staff resources compared with TLS.     

Pre-cut papillotomy with a new papillotome

BACKGROUND: A new papillotome has been developed, an isolated-tip needle-knife papillotome (Iso-Tome) that has a semi-oval-shaped tip of epoxide adhesive to prevent electric leakage from the tip of the incising needle. The coated tip aids in keeping the papillotome tightly in the orifice of the ampulla of Vater and is believed to prevent unintentional deep cuts or perforations. This study was done to evaluate the clinical usefulness of the new papillotome for pre-cut papillotomy. METHODS: From June 2003 to November 2003, 115 patients underwent attempted ERCP. If biliary cannulation failed by the conventional method, pre-cut papillotomy was performed by using the Iso-Tome in the direction of the bile duct. After successful bile-duct cannulation, papillotomy was extended for therapeutic procedures, such as stone removal or stent insertion, in the majority of the cases. Post-ERCP complications were classified according to consensus guidelines. OBSERVATIONS: Pre-cut papillotomy with the Iso-Tome was done in 25 patients (21.7% of cases). Protective pancreatic stents were not used. Of these patients, 11 had common bile duct stones, 7 had pancreatitis, 5 had malignancies, one had sphincter of Oddi dysfunction, and one had bile-duct leak. After pre-cut papillotomy with the Iso-Tome, bile-duct cannulation was successfully achieved in 23 of 25 (92%) patients. Complications occurred in 7 of 25 patients (28%) and consisted of mild pancreatitis in 5 (20%), moderate bleeding in one (4%), and biliary pain in one (4%). All 7 patients with complications were managed medically, and there was no death. CONCLUSIONS: In this pilot study, the isolated-tip needle knife was found to be a clinically useful papillotome for pre-cut papillotomy. Further large comparative studies (with and without pancreatic protective stents) are needed to determine improved efficacy and safety compared with standard techniques.     

Impairment in cognitive and exercise performance during prolonged antarctic residence: effect of thyroxine supplementation in the polar triiodothyronine syndrome

Humans who work in Antarctica display deficits in cognition, disturbances in mood, increased energy requirements, a decline of thyroid hormone products, and an increase of serum TSH. We compared measurements in 12 subjects, before deployment (baseline), with 11 monthly studies during Antarctic residence (AR). After 4 months of AR (period 1), half of the subjects (T(4) group) received L-thyroxine [64 nmol.day(-)(1) (0.05 mg.day(-)(1))]; and the other half, a placebo (placebo group) for the next 7 months of AR (period 2). During period 1, there was a 12.3 +/- 5.1% (P < 0.03) decline on the matching-to-sample (M-t-S) cognitive task and an increase in depressive symptoms, compared with baseline. During the intervention in period 2, M-t-S scores for the T(4)-treated group returned to baseline values; whereas the placebo group, in contrast, showed a reduced M-t-S score (11.2 +/- 1.3%; P < 0.0003) and serum free T(4) (5.9 +/- 2.4%; P < 0.02), compared with baseline. The change in M-t-S score was correlated with the change in free T(4) (P < 0.0003) during both periods, and increases in serum TSH preceded worsening scores in depression, tension, anger, lack of vigor, and total mood disturbance (P < 0.001) during period 2. Additionally, the submaximal work rate for a fixed O(2) use decreased 22.5 +/- 4.9% in period 1 and remained below baseline in period 2 (25.2 +/- 2.3%; P < 0.005) for both groups. After 4 months of AR, the L-thyroxine supplement was associated with improved cognition, which seems related to circulating T(4). Submaximal exercise performance decrements, observed during AR, were not changed with this L-thyroxine dose.     

Seroprevalence of tetanus immunity among noninsulin-dependent diabetes mellitus patients

Tetanus is a preventable disease that continues to affect people in both developing and developed countries. The aim of the present study was to evaluate the immunity profile to tetanus in patients with Type II diabetes mellitus (DM) and to compare them with healthy controls. The tetanus antitoxin levels in 310 diabetic patients (104 males and 206 females) and in 200 healthy controls (72 males and 128 females) were measured by ELISA (Virotech, Germany). The mean antitoxin concentration in patient and control groups were 0.8238+/-1.61 and 0.9978+/-1.49 IU/ml, respectively. There was a statistically significant difference between the two groups (z=-3.520, P=.0001 and odds ratio was 2.367). There was a definitive inverse correlation between the duration of diabetes and tetanus antibody titers (Spearman's correlation analysis, r=-.155, P=.006). A gender-dependent difference in the susceptibility to tetanus was present in the diabetic group with antibody titers being significantly higher in males compared with females (z=-2.267, P=.023). For both of control (chi(2)=20.207, P=.003) and patient (chi(2)=43.532, P=.0001) groups, there was a significant inverse correlation between the tetanus immunity levels and age. Statistically, a significant drop in antibody titers of both groups was found as the period past from the last immunization increased (Pearson correlation analysis: for patient group r=-.364, P=.0001; for control group r=-.143, P=.044). The tetanus antitoxin levels were significantly increased in individuals who had primary immunization during childhood (for patient group chi(2)=17.191, P=.0001; for control group chi(2)=9.911, P=.007). A significant reduction in the level of antitoxin immunity to tetanus in association with an increased susceptibility to infections in patients with diabetes may implicate the need for improving vaccination rates in this patient group.     

Mitral valve surgery in the presence of pulmonary hypertension.

Mitral valve surgery was performed in 59 patients with severe pulmonary hypertension (average systolic pulmonary artery pressure 77.1 +/- 18.6 mmHg; range 50-115 mmHg) between 1983 and 1990. Thirty-eight patients had been subjected to mitral valve replacement, 16 patients both mitral and aortic valve replacement, and 5 patients had open mitral commissurotomy, with an operative (30 day) mortality of 5.0%. These 3 deaths happened during the early postoperative period. Survivors were followed up for a period ranging from 6 months to 7 years with a mean of 36 months. Four late deaths (7.1%) occurred in patients with valve replacement. Actuarial survival was 93 +/- 3% at 5 years, and 90.7 +/- 4.4% at 7 years. Right ventricular catheterization was performed on 14 patients a mean of 38 months following operation. Systolic pulmonary artery pressure had decreased from a mean of 77.1 +/- 18.6 to 39.7 +/- 14.0 mmHg (p less than 0.001) and 90% of the survivors were in New York Heart Association Class 1 or II compared to 23.7% preoperatively. The clinical and hemodynamic findings in this series suggest that severe pulmonary hypertension is not a contraindication, and pulmonary hypertension decreases significantly after mitral valve surgery.     

Periprocedural embolic events related to carotid artery stenting detected by diffusion-weighted MRI: comparison between proximal and distal embolus protection devices.

PURPOSE: To evaluate and compare the efficacy of proximal versus distal embolus protection devices (EPD) during carotid artery angioplasty/stenting (CAS) based on diffusion-weighted magnetic resonance imaging (DW-MRI). METHODS: Forty-four patients (31 men; mean age 68 years, range 48-85) underwent protected CAS and had DW-MRI before and after the intervention. The cohort was analyzed according to the type of EPD used: a proximal EPD was deployed in 25 (56.8%) patients (17 men; mean age 66 years, range 48-85) and a distal filter in 19 (14 men; mean age 70 years, range 58-79). Fifteen (60.0%) patients with proximal protection were symptomatic of the target lesion; in the distal protection group, 10 (52.6%) were symptomatic. RESULTS: New lesions were seen on the postinterventional DW-MRI in 28.0% (7/25) of the proximal EPD group versus 32.6% (6/19) of those with a distal filter (p = NS). The majority were clinically silent. The new lesions in the vascular territory of the stented carotid artery in the group as a whole and per patient were fewer in the proximal EPD group (p = NS). No significant differences were noted in the T(2) appearance of the new lesions or the number of new lesions observed away from the vascular territory of the stented artery. CONCLUSION: Proximal embolus protection devices show a nonsignificant trend toward fewer embolic events, which warrants large-scale studies. Furthermore, proximal protection devices can be useful to control and treat acute in-stent thrombosis.     

Involvement of Oxygen-Derived Free Radicals in L-Arginine-Induced Acute Pancreatitis

This study was aimed at an assessment of the role of oxygen-derived free radicals in the pathogenesis of L-arginine (Arg)-induced acute pancreatitis in rat, by measuring the levels of malonyl dialdehyde (MDA), glutathione peroxidase (GPx), catalase, and superoxide dismutase (Mn- and Cu,Zn-SOD) in the pancreatic tissue, and evaluating the protective effect of the xanthine oxidase inhibitor allopurinol. Acute pancreatitis was induced in male Wistar rats by injecting 2 × 250 mg/100 g body weight of Arg intraperitoneally in a 1-hr interval, as a 20% solution in 0.15 M NaCl. Control rats received the same quantity of glycine. Allopurinol, 100 or 200 mg/kg, was administered subcutaneously 30 min before the first Arg injection. Rats were killed at 6, 12, 24, and 48 hr following Arg administration, and acute pancreatitis was confirmed by a serum amylase level elevation and typical inflammatory features observed microscopically. The serum level of amylase reached the peak level at 24 hr after the Arg injection (30,800 ± 3813 vs 6382 ± 184 units/liter in the control) and normalized at 48 hr. The tissue concentration of MDA was significantly elevated at 24 hr and reached the peak value at 48 hr (5.00 ± 1.75 vs 0.28 ± 0.05 nM/mg protein in the control). The catalase and Mn-SOD activities were significantly decreased throughout the study, while the GPx activity was significantly reduced at 6 and 12 hr, and the Cu,Zn-SOD activity was significantly lower at 12 hr after the Arg injection as compared with the controls. Allopurinol treatment markedly reduced the serum amylase elevation (12.631 ± 2.257 units/liter at 24 hr) and prevented the increase in tissue MDA concentration (0.55 ± 0.09 nM/mg protein at 48 hr). Both doses of allopurinol significantly ameliorated the pancreatic edema, necrosis, and inflammation at 48 hr after Arg administration. Oxygen-derived free radicals are generated at an early stage of Arg-induced acute pancreatitis. Prophylactic allopurinol treatment prevents the generation of reactive oxygen metabolites, reduces the serum amylase concentration, and exerts a beneficial effect on the development of histopathological changes.     

A new technique: Right ventriculography using a preshaped catheter

Right ventriculography with a preshaped catheter (J- or L-shaped) was evaluated in make the diagnosis of tricuspid regurgitation. Thirty normal subjects who did not have valvular disease showed no evidence of tricuspid regurgitation or premature ventricular contractions during injection except in one case. On the other hand, 24 patients with combined aortic and mitral valve disease showed mild to moderate tricuspid regurgitation in 11 patients and severe tricuspid regurgitation in eight patients. Only two patients developed frequent run of premature ventricular contraction during injection. Seven patients with severe tricuspid regurgitation were found to have severe tricuspid regurgitation during surgery. No evidence of tricuspid regurgitation was found In all six patients with isolated aortic valve disease. We can conclude that right ventriculography by the preshaped catheter improves the diagnostic accuracy of tricuspid regurgitation and a grading system of tricuspid regurgitation by angiography is proposed.     

Amphotropic or Gibbon Ape Leukemia Virus Retrovirus Binding and Transduction Correlates with the Level of Receptor mRNA in Human Hematopoietic Cell Lines

ABSTRACT: The low level of amphotropic retrovirus mediated gene transfer into human hematopoietic stem cells (HSC) has been an impediment to gene therapy for hematopoietic diseases (1). We have previously shown that mouse and human HSC have low levels of the mRNA encoding PiT-2, the amphotropic retrovirus receptor. We hypothesized that the low level of PiT-2 mRNA was responsible for the low frequency of transduction of HSC by amphotropic retroviral vectors (2). In this study we compared the level of PiT-2 and PiT-1, the Gibbon Ape Leukemia Virus receptor (GaLV), in 5 human tissue culture cell lines. PiT-2 and PiT-1 mRNA levels were highest in K562 cells and lowest in HL60 cells. In hematopoietic cell lines, the level of PiT-2 or PiT-1 mRNA correlated directly with retrovirus binding and transduction with the appropriate (amphotropic or GaLV) retrovirus vector. The level of expression of PiT-2 and PiT-1 mRNA could be increased by treatment of HL60 cells with either PMA or Interleukin-1α. The increase in the level of PiT-2 and PiT-1 mRNA correlated with increased transduction with both amphotropic and GaLV retroviral vectors. We conclude that the improved transduction was a direct effect of the increased levels of receptor mRNA and unrelated to changes in the cell cycle status.