Molecular epidemiology demonstrated three emerging clusters of human immunodeficiency virus type 1 subtype B infection in Hong Kong

We conducted a molecular epidemiological study on newly diagnosed human immunodeficiency virus type 1 (HIV-1)-infected patients in Hong Kong to identify the epidemiological linkage of HIV-1 infection in the locality. Reverse transcription polymerase chain reaction (RT-PCR) for HIV-1 was performed on newly diagnosed HIV-1-positive sera collected from January 2002 to December 2006. PCR products correspond to the env C2V3V4 region and gag p17/p24 junction of the HIV-1 genome were nucleotide sequenced. Phylogenetic analyses performed on the acquired nucleotide sequences revealed that CRF01_AE and subtype B were the two dominant HIV-1 subtypes. Analyses also demonstrated the presence of three emerging HIV-1 clusters among the subtype B sequences in Hong Kong. Individual cluster possesses a unique cluster-specific amino acid signature for identification. Data show that one of the clusters (Cluster I) is rapidly expanding. In addition to the unique cluster-specific amino acid signature, the majority of sequences in Cluster I harbor a 6-amino acid insertion at the gag p17/p24 junction in a region that is thought to be closely associated with HIV-1 infectivity.

Cytokine gene polymorphism and progression of renal and cardiovascular diseases

Cytokines are important modulators of inflammation. The balance between pro- and anti-inflammatory cytokines determines whether the intensity of inflammatory response is within physiological limits or in the pathological range. The cytokine network is highly complex, containing interactive cascades of gene activation and suppression. Both chronic kidney disease (CKD) and end-stage renal disease (ESRD) are characterized by elevated levels of proinflammatory cytokines and markers of inflammation. Cytokines may modulate the risk for progression of renal disease and the susceptibility to cardiovascular disease (CVD). Polymorphisms of cytokine genes may influence gene transcription and cytokine secretion and thereby modulate the risk of progression of renal and CVDs. The observed inconsistencies in the data regarding associations between single-nucleotide gene polymorphisms (SNPs) and their presumed phenotypic expression emphasize the need to recognize several conceptual and methodological aspects such as haplotypic rather than single SNP variations and the influence of pathway genes with synergistic or antagonistic effects that ultimately determine the phenotype. It is conceivable that when a patient with a high-risk cytokine genotype develops CKD, the risk for CVD is increased. Early interventions in CKD patients with high-risk genotypes may slow the progression of renal disease and also decrease CV mortality and morbidity.

Detection of circulating tumor cells (CTCs) in patients with hepatocellular carcinoma (HCC)

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Background: Allard et al. (2004) has established the accuracy, sensitivity, reliability and linearity of circulating tumor cells (CTCs) detection using the CellSearch System. 57% prostate cancers, 37% breast cancers, 37% ovarian cancers, 30% colorectal cancers, and 20% lung cancers specimens had >= 2 CTCs per 7.5 mL of blood. Only 0.3% healthy non-malignant disease subjects had >= 2 CTCs per 7.5 mL of blood. Cristofanilli et al.(2004,2005) have shown that CTCs at baseline and first follow-up were a significant prognostic factor for survival in metastatic breast cancer patients. However, HCC data on CTCs are not available. Methods: 20 locally advance or metastatic HCC patients who had not received prior treatment had been recruited after informed consent and 7.5 mL of blood were collected using the CellSave Preservative tubes (Veridex LLC, Raritan, NJ) that prevents CTCs degradation. The CellSearch system (Veridex LLC) similar to the previous studies was used to analyze the specimen. The CellSearch system consists the CellPrep system, the CellSearch Epithelial Cell Kit, and the CellSpotter Analyzer. All the procedures and interpretation of results followed closely with the quality control procedure of Veridex LLC including accreditation of trained laboratory personnel. Results: 13/20 (65%) had locally advanced disease and the rest had metastatic HCC. All patients had multiple lesions. 9/20 (45%) patients had detectable CTCs, 7/20 (35%) had >= 2 CTCs, and about 5/20 (20%) had 5 or more CTCs. For locally advanced HCC 4/13 (31%) patients had >= 2 CTCs per 7.5 mL of blood. For HCC patients with metastatic diseases 3/7 (43%) patients had >= 2 CTCs per 7.5 mL of blood. Conclusions: HCC patients with locally advance or metastatic disease had detectable CTCs in 7.5 mL of blood. We expected that the performance of CTCs in HCC is similar to that of breast cancer. Future study of using CTCs as prognostic factor at baseline and during treatment for HCC is being planned.

No significant financial relationships to disclose.

Mode of inactivation of probiotic bacteria affects interleukin 6 and interleukin 8 production in human intestinal epithelial-like Caco-2 cells

Five lactic acid bacteria and two bifidobacteria strains were heat or irradiation inactivated. Inactivated cultures were evaluated for their effects on cytokines interleukin (IL) 6 and IL-8 production in human intestinal-like Caco-2 cells. For both heat- and irradiation-inactivated cultures, production of IL-6 and IL-8 was dependent on the specific microorganism. However, with all of the cultures, both IL-6 and IL-8 production was significantly higher (P < 0.05) in Caco-2 cells that were treated with heat-inactivated probiotic bacteria compare to the irradiation-inactivated bacteria. In the majority of the cases, heat-inactivated bacteria induced IL-6 and IL-8 production, whereas irradiation-inactivated bacteria attenuated both cytokine production. Our results indicate that the same probiotic bacteria used in the same cell culture could provide opposite cytokine production and immune modulation results based on its mode of inactivation; therefore, it is important to describe inactivation methods and conditions in detail when characterizing probiotic effects.

Nutritional status and prognosis in cirrhotic patients

BACKGROUND AND AIM

The potential prognostic value for survival of nutritional status in cirrhotics after adjusting Child-Pugh classification and Model for End-Stage Liver Disease has not been evaluated.

METHODS

We used Kaplan-Meier and Cox proportional hazards regression models to identify factors associated with mortality in a cohort of 222 cirrhotics [M/F:145/77 median age 52 (18-68) years] with prospectively collected nutritional parameters as well as modified subjective global nutritional assessment, Royal Free Hospital-Subjective Global Assessment index. Follow-up was censored at the time of transplantation. Other variables were ones in Child-Pugh and Model for End-Stage Liver Disease scores, age, aetiology of cirrhosis and renal function.

RESULTS

Pretransplant mortality (Kaplan-Meier) was 21% by 2 years (135 patients were transplanted). Among the nutritional parameters, only Royal Free Hospital-Subjective Global Assessment remained significantly associated with mortality in multivariable models (P = 0.0006). The final model included the following variables: urea (P = 0.0001), Royal Free Hospital-Subjective Global Assessment (P = 0.003), age (P = 0.0001), Child-Pugh grade (P = 0.009) and prothrombin time (P = 0.003). The results were similar when the Child-Pugh grade was replaced by the Model for End-Stage Liver Disease score in the model, and whether a competing risks model was used.

CONCLUSIONS

Nutritional indices add significantly to both Child-Pugh grade and Model for End-Stage Liver Disease scores when assessing the patient prognosis.

A radiological diary of gallstone migration in a patient with acute pancreatitis

This case report is interesting in radiologically showing migration of stones from the gallbladder via the biliary tree and into the gastrointestinal tract.

Spectrum of EGFR mutations associated with non-small cell lung cancer in an Asian Chinese population

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Background: Somatic mutations in tyrosine kinase (TK) domain of the EGFR gene, predicting for sensitivity to TK inhibition therapy, are over-represented in lung cancer with adenocarcinoma or bronchioloalveolar histology, non-smokers, female gender and East Asian ethnicity. Methods: We prospectively screened for EGFR mutations at exons 19–21 on micro-dissected specimen enriched for tumor cells by direct nucleotide sequencing in Hong Kong Chinese patients. Results: From May 2005 onwards, a total of 27 patients were analyzed. They comprised 11 males and 16 females with a median age of 67 years. Histological diagnoses were adenocarcinoma (n = 22), bronchioloalveolar carcinoma (n = 4) and squamous cell carcinoma (n = 1). Samples included primary tumor (n = 20) as well as metastatic lesions (n = 7). EGFR mutations were detected in 17 patients (63%), the most common being L858R at exon 21 (n = 7) followed by exon 19 deletions (del(746–750) = 3, del(747–751) = 1, del(747–753) = 3) and G719C at exon 18 (n = 1). Two patients showed novel EGFR mutations, namely 4-base pair insertion deletion at exon 19 leading to substitution of Glu746-Leu747 by Val746-Pro747 and three base pair deletion at exon 18 leading to replacement of Glu709-Thr710 by Asp. Furthermore, two patients showed double mutations, including novel S768I at exon 20 in combination with G719C, and novel K860I at exon 21 in combination with L858R. Finally, one patient showed homozygous del(747–753) as detected by sequencing in both primary lung tumor and brain secondary, which might represent loss of heterozygosity. Conclusions: Similar to other series, two hotspots i.e. exon 19 deletion and L858 account for the majority (82%) of detectable EGFR mutations in our patient population. For the rare and novel variants, it would be of interest to document the clinical responsiveness to TK inhibitors gefitinib and erlotinib, so that a more complete picture of cancer genotype phenotype correlation can be achieved.

No significant financial relationships to disclose.

Analysis of purified gp96 preparations from rat and mouse livers using 2-D gel electrophoresis and tandem mass spectrometry

The stress protein gp96 exhibits a number of immunological activities, the majority of studies into which have used gp96 purified from a variety of tissues. On the basis of 1-D gel electrophoresis, the purity of these preparations has been reported to range between 70% and 99%. This study analyzed gp96 preparations from rat and mouse livers using 2-D gel electrophoresis and liquid chromatography electrospray ionization tandem mass spectrometry (MS-MS). The procedure for purifying gp96 was reproducible, as similar protein profiles were observed in replicate gels of gp96 preparations. The purity of the preparations was typically around 70%, with minor co-purified proteins of varying molecular weights and mobilities being present. Dominant bands at 95-100 kDa in preparations from Wistar rats and C57BL/6 mice were identified as gp96 by ECL Western blotting. Multiple bands having similar, yet distinct molecular weights and differing pI mobility on ECL Western blots were confirmed as being gp96 in preparations from Wistar rats using MS-MS. The most striking feature of the 2-D gel analysis was the presence of additional dominant bands at 55 kDa in preparations from Wistar rats, and at 75-90 kDa in preparations from C57BL/6 mice. These were identified as gp96 by ECL Western blotting and, in the case of preparations from Wistar rats, by MS-MS. Although the lower molecular weight, gp96-related molecules might be partially degraded gp96, their reproducible presence, definition and characteristics suggest that they are alternative, species-specific isoforms of the molecule. A 55 kDa protein which exhibited a lower pI value than gp96 was present in all preparations and this was identified as calreticulin, another putative immunoregulatory molecule. This study confirms the reproducibility of the gp96 purification protocol and reveals the presence of multiple gp96 isoforms, some of which likely result from post-translational modifications such as differential glycosylation and phosphorylation.

Hypocalcaemia and Parathyroid Hormone Assay Following Total Thyroidectomy: Predicting the Future

BACKGROUND

Ambulatory surgery (23:59-hour hospital stay) is gaining popularity in endocrine surgery. Hypocalcaemia is common following total thyroidectomy. Identifying patients with low risk of hypocalcaemia may facilitate early discharge (24-hour stay).

METHODS

We conducted a prospective study including all patients undergoing total thyroidectomy. Blood samples were taken immediately following skin closure and the following morning for parathyroid hormone (PTH) and calcium measurement. Calcium supplements were routinely given when serum calcium was below 2.0 mmol/l.

RESULTS

Thirty patients (27 females, 3 males) underwent total thyroidectomy (including 4 nodal dissection) for multinodular goitre (14), Graves' disease (11), papillary (4) and follicular (1) thyroid carcinoma. Twelve patients developed symptomatic transient hypocalcaemia. Based on morning calcium of < 2.0 mmol/l as trigger for calcium supplementation, 8 patients received calcium supplement with 4 false negatives, resulting in a specificity of 94.4%, sensitivity of 66.7%, positive predictive value (PPV) of 88.9% and negative predictive value (NPV) of 81%. Based on PTH levels (< 1.5 pmol/l) immediately following skin closure, 11 patients would receive calcium supplement, with 1 false negative resulting in a specificity of 83.3%, sensitivity of 91.7%, PPV of 78.6% and NPV of 93.8%. If supplementation is based on PTH levels (< 1.5 pmol/l) immediately following skin closure and morning calcium level (< 2.0 mmol/l), all 12 symptomatic patients will be correctly treated, with 4 false positives resulting in a combined specificity of 77.8%, sensitivity of 100%, PPV of 75% and NPV of 100%.

CONCLUSIONS

Combining the immediate postoperation PTH levels (< 1.5 pmol/l) and morning serum calcium (< 2.0 mmol/l) can accurately identify patients at risk of hypocalcaemia following total thyroidectomy, allowing safe, early discharge.

Relationship between myocardial perfusion and dysfunction in diabetic cardiomyopathy: a study of quantitative contrast echocardiography and strain rate imaging

OBJECTIVE

To use quantitative myocardial contrast echocardiography (MCE) and strain rate imaging (SRI) to assess the role of microvascular disease in subclinical diabetic cardiomyopathy.

METHODS

Stress MCE and SRI were performed in 48 patients (22 with type II diabetes mellitus (DM) and 26 controls), all with normal left ventricular systolic function and no obstructive coronary disease by quantitative coronary angiography. Real-time MCE was acquired in three apical views at rest and after combined dipyridamole-exercise stress. Myocardial blood flow (MBF) was quantified in the 10 mid- and apical cardiac segments at rest and after stress. Resting peak systolic strain rate (SR) and peak systolic strain (epsilon) were calculated in the same 10 myocardial segments.

RESULTS

The DM and control groups were matched for age, sex and other risk factors, including hypertension. The DM group had higher body mass index and left ventricular mass index. Quantitative SRI analysis was possible in all patients and quantitative MCE in 46 (96%). The mean epsilon, SR and MBF reserve were all significantly lower in the DM group than in controls, with diabetes the only independent predictor of each parameter. No correlation was seen between MBF and SR (r = -0.01, p = 0.54) or between MBF and epsilon (r = -0.20, p = 0.20).

CONCLUSIONS

Quantitative MCE shows that patients with diabetes but no evidence of obstructive coronary artery disease have impaired MBF reserve, but abnormal transmural flow and subclinical longitudinal myocardial dysfunction are not related.

Mercury concentrations in gonad, liver, and muscle of white sturgeon Acipenser transmontanus in the lower Columbia River

This study determined the partitioning of total mercury in liver, gonad, and cheek muscle of white sturgeon (Acipenser transmonatus) in the lower Columbia River. The relationship between tissue mercury concentrations and various physiologic parameters was assessed. White sturgeon were captured in commercial fisheries in the estuary and Bonneville, The Dalles, and John Day Reservoirs. Condition factor (CF), relative weight (Wr), and gonadosomatic index (GSI) were determined for each fish (n = 57). Gonadal tissue was examined histologically to determine sex and stage of maturity. Liver (n = 49), gonad (n = 49), and cheek muscle (n = 57) were analyzed for total mercury using cold-vapor atomic fluorescence spectrophotometry. Tissue protein concentrations were measured by ultraviolet-visible spectroscopy. Plasma was analyzed for testosterone (T), 11-ketotestosterone (KT), and 17ss-estradiol (E2) using radioimmunoassay. Mean tissue mercury concentrations were higher in muscle compared with liver and gonad at all sampling locations, except Bonneville Reservoir where mean liver mercury content was the highest tissue concentration observed in the study. Significant negative correlations between plasma androgens (T and KT) and muscle mercury content and plasma E2 and liver mercury content were found. A significant positive linear relationship between white sturgeon age and liver mercury concentrations was evident. Significant negative correlations between CF and relative weight and gonad and liver mercury content were found. In addition, immature male sturgeon with increased gonad mercury content had decreased GSIs. These results suggest that mercury, in the form of methylmercury, may have an effect on the reproductive potential of white sturgeon.

Increased expression of type 2 3alpha-hydroxysteroid dehydrogenase/type 5 17beta-hydroxysteroid dehydrogenase (AKR1C3) and its relationship with androgen receptor in prostate carcinoma

Type 2 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD) is a multi-functional enzyme that possesses 3alpha-, 17beta- and 20alpha-HSD, as well as prostaglandin (PG) F synthase activities and catalyzes androgen, estrogen, progestin and PG metabolism. Type 2 3alpha-HSD was cloned from human prostate, is a member of the aldo-keto reductase (AKR) superfamily and was named AKR1C3. In androgen target tissues such as the prostate, AKR1C3 catalyzes the conversion of Delta(4)-androstene-3,17-dione to testosterone, 5alpha-dihydrotestosterone to 5alpha-androstane-3alpha,17beta-diol (3alpha-diol), and 3alpha-diol to androsterone. Thus AKR1C3 may regulate the balance of androgens and hence trans-activation of the androgen receptor in these tissues. Tissue distribution studies indicate that AKR1C3 transcripts are highly expressed in human prostate. To measure AKR1C3 protein expression and its distribution in the prostate, we raised a monoclonal antibody specifically recognizing AKR1C3. This antibody allowed us to distinguish AKR1C3 from other AKR1C family members in human tissues. Immunoblot analysis showed that this monoclonal antibody binds to one species of protein in primary cultures of prostate epithelial cells and in LNCaP prostate cancer cells. Immunohistochemistry with this antibody on human prostate detected strong nuclear immunoreactivity in normal stromal and smooth muscle cells, perineurial cells, urothelial (transitional) cells, and endothelial cells. Normal prostate epithelial cells were only faintly immunoreactive or negative. Positive immunoreactivity was demonstrated in primary prostatic adenocarcinoma in 9 of 11 cases. Variable increases in immunoreactivity for AKR1C3 was also demonstrated in non-neoplastic changes in the prostate including chronic inflammation, atrophy and urothelial (transitional) cell metaplasia. We conclude that elevated expression of AKR1C3 is highly associated with prostate carcinoma. Although the biological significance of elevated AKR1C3 in prostatic carcinoma is uncertain, AKR1C3 may be responsible for the trophic effects of androgens and/or PGs on prostatic epithelial cells.

Urinary incontinence after radical retropubic prostatectomy is not related to patient body mass index

To determine if a relationship exists between patient body habitus and urinary incontinence after radical retropubic prostatectomy (RRP) for clinically localized prostate cancer. A questionnaire developed by combining parts of lower urinary tract symptom questionnaires concerning voiding symptoms after RRP was mailed to 268 consecutive patients who underwent RRP over a 2-year period. The interval between surgery and questionnaire administration was greater than 24 months for each patient. No interval was greater than 54 months. The questionnaire attempted to overcome the subjectivity of patient documented urinary incontinence by probing different aspects of each patient's voiding symptoms. Body mass index (BMI), obtained from preoperative anesthesia records, was used as the measurement for body habitus. Pearson correlations were used to determine relationships between BMI and responses and the independent t-test was used to determine differences between grouped responses and BMI. One hundred and eighty-two of 268 (68%) questionnaires were returned. No relationship was detected between BMI and patient estimates of urinary control, QOL relating to urinary symptoms, severity of stress incontinence, or use of protection (pad use). As well, no statistically significant relationship was found between BMI and a patient's willingness to undergo RRP again, based on his voiding symptoms, if given the choice. In conclusion, although patient body habitus may be related to other clinical outcomes following RRP, there does not appear to be a relationship of BMI to post-RRP urinary incontinence.