Prevalence of Helicobacter pylori vacA, cagA, cagE, iceA and babA2 genotypes in Thai dyspeptic patients.

OBJECTIVES: To investigate the prevalence of the vacA, cagA, cagE, iceA, and babA2 genotypes in Helicobacter pylori strains isolated from Thai dyspeptic patients, and to determine whether any correlation exists between these genotypes and clinical manifestations. METHODS: Helicobacter pylori was examined in 112 patients (62 with non-ulcer dyspepsia (gastritis), 34 with peptic ulcer disease, and 16 with gastric cancer (GCA)), detected by culture or direct detection from gastric biopsies. Allelic variants of the vacA, cagA, cagE, iceA, and babA2 genotypes were identified by using the polymerase chain reaction. RESULTS: The positive rates for the vacAs1, vacAs2, cagA, cagE, iceA1, iceA2, and babA2 genes in H. pylori of dyspeptic patients were 100%, 0%, 98.2%, 88.4%, 45.5%, 33.1%, and 92%, respectively. The allelic variant vacAs1m1 was more prevalent (58%) than vacAs1m2 (42%). The cagA and cagE genes were commonly found together (87.5%). The most predominant genotypes were vacAs1m1, cagA, cagE, iceA1, and babA2. The various genes alone or in combination had no statistically significant association with the clinical outcomes (p>0.05). CONCLUSION: Neither single gene nor combination of vacA, cagA, cagE, iceA, and babA2 genes was significantly helpful in predicting the clinical outcome of H. pylori infection in Thai patients. The high prevalence of these genes in H. pylori isolated from Thai patient groups suggests that H. pylori strains are geographically dependent.     

Natural logarithmic formula: Not an alternative method for estimating Kt/V in paediatric haemodialysis

Many methods have been used to measure urea kinetic modelling (UKM) in haemodialysis patients. Formal UKM has been recommended as the best method to calculate Kt/V in adult and paediatric patients. The natural logarithmic formula for Kt/V was established as the best alternative for adult patients but there is no data comparing the two methods of determining UKM in children and adolescents. We compared Kt/V derived from formal UKM with that derived from the natural logarithmic formula in seven patients having 74 episodes of treatment with haemodialysis. The patients' ages ranged from 7 to 16 years. The mean percent difference between the two methods was 11.4 ± 9.0% and the total percent error was 29.3%. When compared for different means of vascular access, the mean percent difference between the two methods for arteriovenous (AV) vascular access ranged from 3.7% in a 7 year old to 9.6% in a 10 year old, and the mean percent difference in the venovenous (VV) vascular access subgroup ranged from 16.5% in a 7 year old to 25.5% in a 10 year old. These results show that the natural logarithmic formula consistently overestimates Kt/V in both AV and VV vascular access, suggesting it may not be adequate for a paediatric haemodialysis population.     

Survey of Angiostrongylus cantonensis in rats and giant African land snails in Phitsanulok province, Thailand

ObjectiveTo survey the Angiostrongylus cantonensis (A. cantonensis) or the rat lungworm in a rat, definitive host, and in a giant African land snail (Achatina fulica), the intermediate host, in Phitsanulok, Thailand.MethodsRats and giant African land snails were captured from Tha Pho sub-district, Phitsanulok, Thailand. Rats were killed and examined for adult A. cantonensis. The artificial digestion method following Baermann technique were used for isolation third stage larvae of A. cantonensis.ResultsSixty-two rats were captured and they were identified as Rattus argentiventer, Rattus rattus (R. rattus), Bandicota savilei, and Bandicota indica but only one animal (R. rattus) of 62 rats (1.61%) was positive with adult worm of A. cantonensis. The third stage larvae of A. cantonensis were examined on 307 Angiostrongylus fulica snails. It was found that the overall infection rate was 12.38% (38 infected out of 307 Achatina snails).ConclusionsThis study demonstrates that A. cantonensis is available in the natural hosts of Phitsanulok. This suggests that the transmissions of this parasite to human may occur in this region.     

Age estimation using aspartic amino acid racemization from a femur

Age estimation is an important step in post-mortem investigation, and the aspartic acid racemization (AAR) of dentin is the best tool for age estimation from human remains. However, teeth may not be found or sufficiently preserved to analyse the Dextro/Levo (D/L) ratio, and so age estimation using AAR from other organs, such as bones, is required. The current study evaluated age estimation methods using aspartic amino acid racemization from a femur in a Thai population. D/L ratio analysis using high-performance liquid chromatography (HPLC) was performed on 40 femoral bones from 24 males and 16 females, and the correlation between D/L ratio and age was 0.8316. The correlation coefficient in the male sample was greater than the female samples – 0.912 and 0.716, respectively. The standard error of estimation of all samples was 11.01 years. The correlation between the D/L ratio and the age of the total amino acid fraction from a femur was not as strong as from dentin and single protein purification, such as elastin and osteocalcin, but this method was necessary because teeth may not be found with body remains, and this method is not too complicated for routine forensic work.     

Functional outcome following excision of a tumour and reconstruction of the distal radius

We retrospectively studied the functional and oncological results of 15 patients after reconstruction of the distal radius with osteoarticular allograft or non-vascularised fibular graft following wide excision of an aggressive benign or malignant tumour. Eight patients underwent osteoarticular allograft and seven patients had a non-vascularised autogenous fibular graft reconstruction. The average time for incorporation of the graft was 6 and 5 months in each reconstruction respectively. There was no tumour recurrence after follow up over 41.5-95.5 (average 60.5) months. All patients had good and excellent functional results. Three patients in the group reconstructed with osteoarticular allograft had plate loosening and graft fractures which were successfully treated subsequently.     

Custom cross-pin fixation of 32 tumor endoprostheses stems

The main cause of mechanical failure of primary and revision cemented tumor endoprosthetic stems is aseptic loosening. The placement of custom designed pins through the bone, the cement, and the stem can create a bone-cement-prosthesis composite that resists the rotatory stresses that lead to aseptic loosening. At risk situations include large primary reconstructions where the residual short metaphyseal articular segments lack sufficient length and cortical contact to provide lasting fixation, and revision prostheses that are to be recemented into straight diaphyseal segments that already have experienced aseptic loosening. Current modular tumor endoprosthetic systems have improved availability and allow for some intraoperative flexibility, but they do not provide solutions for these at risk scenarios. Additional customization is necessary. We report on the 16-year experience with 32 custom cross-pin stems at the University of California, Los Angeles (UCLA). Twenty of these patients have been followed up for more than 2 years. There were three mechanical failures, three patients were lost to followup, and five patients died of disease. There have been no cases of aseptic loosening in this series. Cross-pin fixation has been effective when used in carefully selected cases.     

Challenges in the discontinuation of chronic hepatitis B antiviral agents

Long-term antiviral treatment of chronic hepatitis B patients has been proven to be beneficial in reducing liver-related complications. However, lengthy periods of daily administration of medication have some inevitable drawbacks, including decreased medication adherence, increased cost of treatment, and possible longterm side effects. Currently, discontinuation of antiviral agent has become the strategy of interest to many hepatologists, as it might alleviate the aforementioned drawbacks and increase the probability of achieving functional cure. This review focuses on the current evidence of the outcomes following stopping antiviral treatment and the factors associated with subsequent hepatitis B virus relapse, hepatitis B surface antigen clearance, and unmet needs.