Association of Met420del Variant of Metformin Transporter Gene SLC22A1 with Metformin Treatment Response in Ethiopian Patients with Type 2 Diabetes

Objective

This study aimed to evaluate whether the M420del variants of SLC22A1 (rs72552763) is associated with metformin treatment response in Ethiopian patients with type 2 diabetes mellitus (T2DM).

Patients and Methods

A prospective observational cohort study was conducted on 86 patients with T2DM who had been receiving metformin monotherapy for <1 year. Patients showing ≥0.5% reduction in HbA1c levels from baseline within 3 months and remained low for at least another 3 months were defined as responders while those patients with <0.5% reduction in HbA1c levels and/or those whom started a new class of glucose-lowering drug(s) because of unsatisfactory reduction were defined as non-responders. In addition, good glycemic control was observed when HbA1c ≤7.0%, and the above values were regarded as poor. Genotyping of rs72552763 SNP was performed using TaqMan® Drug Metabolism Enzyme Genotyping Assay and its association with metformin response and glycemic control were assessed by measuring the change in HbA1c and fasting blood glucose levels using Chi-square, logistic regression and Mann-Whitney U-test. Statistical significance was set at p <0.05.

Results

The minor allele frequency of the rs72552763 SNP of SLC22A1 was 9.3%. Metformin response was significantly higher in deletion_GAT (del_G) genotypes as compared to the wild-type GAT_GAT (G_G) genotypes. Furthermore, a significantly lower median treatment HbA1 level was found in del_G genotypes as compared to G_G genotypes. However, the association of rs72552763 with metformin response was not replicated at the allele level. In contrast, the minor del_allele was significantly associated with good glycemic control compared to the G_allele, though not replicated at del_G genotypes level.

Conclusion

This study demonstrated that metformin response was significantly higher in study participants with a heterozygous carrier of M420del variants of SLC22A1 as compared to the wild-type G_G genotypes after 3 months of treatment.

Molecular Targets of Aptamers in Gastrointestinal Cancers: Cancer Detection, Therapeutic Applications, and Associated Mechanisms

Gastrointestinal (GI) cancers are among the most common cancers that impact the global population, with high mortality and low survival rates after breast and lung cancers. Identifying useful molecular targets in GI cancers are crucial for improving diagnosis, prognosis, and treatment outcomes, however, limited by poor targeting and drug delivery system. Aptamers are often utilized in the field of biomarkers identification, targeting, and as a drug/inhibitor delivery cargo. Their natural and chemically modifiable binding capability, high affinity, and specificity are favored over antibodies and potential early diagnostic imaging and drug delivery applications. Studies have demonstrated the use of different aptamers as drug delivery agents and early molecular diagnostic and detection probes for treating cancers. This review aims to first describe aptamers' generation, characteristics, and classifications, also providing insights into their recent applications in the diagnosis and medical imaging, prognosis, and anticancer drug delivery system of GI cancers. Besides, it mainly discussed the relevant molecular targets and associated molecular mechanisms involved, as well as their applications for potential treatments for GI cancers. In addition, the current applications of aptamers in a clinical setting to treat GI cancers are deciphered. In conclusion, aptamers are multifunctional molecules that could be effectively used as an anticancer agent or drug delivery system for treating GI cancers and deserve further investigations for clinical applications.

Psychosocial Risk Factors Associated with Lifetime Amphetamine-Type Stimulants (ATS) Dependence in Drug Detention Centres: Perspectives from the Multiethnicity Study

ATS dependence in Malaysia is growing tremendously across multiracial Malaysian groups, increasing concerns among public health experts and the community. This study highlighted the chronicity of ATS dependence and factors associated with ATS use. Interviewer-administered questionnaires were administered using ASSIST 3.0. A total of N = 327 multiracial people who use ATS were enrolled in this study. The study findings show that 190/327 (58.1%) respondents were ATS dependent. Malays reported the highest number of ATS-dependent (55.8%), followed by Bajau (21.6%) and Kadazan-Dusun (16.8%) ethnic. Across all races, three factors were significantly associated with the ATS dependence: respondents who had a lifetime history of needle sharing aOR = 0.023 (95% CI: 0.003, 0.183) and a lifetime history of heroin use aOR = 0.192 (95% CI: 0.093, 0.396) were at a reduced odd of ATS dependent. Meanwhile, being married reduced the likelihood of becoming dependent on ATS with aOR = 0.378 (95% CI: 0.206, 0.693) compared to being single or divorced. This study revealed that the use of ATS among multiracial Malaysians is alarmingly high, including those in detention centers. Comprehensive harm reduction strategies are urgently needed to prevent the spreading of infectious diseases and other negative health consequences associated with ATS use.

SLC1A2 Gene Polymorphism Influences Methamphetamine-Induced Psychosis

SLC1A2 is a gene encoded for the excitatory amino acid transporter 2 which is responsible for glutamate reuptake from the synaptic cleft in the central nervous system. Recent studies have suggested that polymorphisms on glutamate transporters can affect drug dependence, leading to the development of neurological diseases and psychiatric disorders. Our study investigated the association of rs4755404 single nucleotide polymorphism (SNP) of the SLC1A2 gene with methamphetamine (METH) dependence and METH-induced psychosis and mania in a Malaysian population. The rs4755404 gene polymorphism was genotyped in METH-dependent male subjects (n = 285) and male control subjects (n = 251). The subjects consisted of the four ethnic groups in Malaysia (Malay, Chinese, Kadazan-Dusun, and Bajau). Interestingly, there was a significant association between rs4755404 polymorphism and METH-induced psychosis in the pooled METH-dependent subjects in terms of genotype frequency (p = 0.041). However, there was no significant association between rs4755404 polymorphism and METH dependence. Also, the rs455404 polymorphism was not significantly associated with METH-induced mania for both genotype frequencies and allele frequencies in the METH-dependent subjects, regardless of stratification into the different ethnicities. Our study suggests that the SLC1A2 rs4755404 gene polymorphism confers some susceptibility to METH-induced psychosis, especially for those who carry the GG homozygous genotype.

Three Members of Transmembrane-4-Superfamily, TM4SF1, TM4SF4, and TM4SF5, as Emerging Anticancer Molecular Targets against Cancer Phenotypes and Chemoresistance

There are six members of the transmembrane 4 superfamily (TM4SF) that have similar topology and sequence homology. Physiologically, they regulate tissue differentiation, signal transduction pathways, cellular activation, proliferation, motility, adhesion, and angiogenesis. Accumulating evidence has demonstrated, among six TM4SF members, the regulatory roles of transmembrane 4 L6 domain family members, particularly TM4SF1, TM4SF4, and TM4SF5, in cancer angiogenesis, progression, and chemoresistance. Hence, targeting derailed TM4SF for cancer therapy has become an emerging research area. As compared to others, this review aimed to present a focused insight and update on the biological roles of TM4SF1, TM4SF4, and TM4SF5 in the progression, metastasis, and chemoresistance of various cancers. Additionally, the mechanistic pathways, diagnostic and prognostic values, and the potential and efficacy of current anti-TM4SF antibody treatment were also deciphered. It also recommended the exploration of other interactive molecules to be implicated in cancer progression and chemoresistance, as well as potential therapeutic agents targeting TM4SF as future perspectives. Generally, these three TM4SF members interact with different integrins and receptors to significantly induce intracellular signaling and regulate the proliferation, migration, and invasion of cancer cells. Intriguingly, gene silencing or anti-TM4SF antibody could reverse their regulatory roles deciphered in different preclinical models. They also have prognostic and diagnostic value as their high expression was detected in clinical tissues and cells of various cancers. Hence, TM4SF1, TM4SF4, and TM4SF5 are promising therapeutic targets for different cancer types preclinically and deserve further investigation.

Matrix Metalloproteinases in Chemoresistance: Regulatory Roles, Molecular Interactions, and Potential Inhibitors

Cancer is one of the major causes of death worldwide. Its treatments usually fail when the tumor has become malignant and metastasized. Metastasis is a key source of cancer recurrence, which often leads to resistance towards chemotherapeutic agents. Hence, most cancer-related deaths are linked to the occurrence of chemoresistance. Although chemoresistance can emerge through a multitude of mechanisms, chemoresistance and metastasis share a similar pathway, which is an epithelial-to-mesenchymal transition (EMT). Matrix metalloproteinases (MMPs), a class of zinc and calcium-chelated enzymes, are found to be key players in driving cancer migration and metastasis through EMT induction. The aim of this review is to discuss the regulatory roles and associated molecular mechanisms of specific MMPs in regulating chemoresistance, particularly EMT initiation and resistance to apoptosis. A brief presentation on their potential diagnostic and prognostic values was also deciphered. It also aimed to describe existing MMP inhibitors and the potential of utilizing other strategies to inhibit MMPs to reduce chemoresistance, such as upstream inhibition of MMP expressions and MMP-responsive nanomaterials to deliver drugs as well as epigenetic regulations. Hence, manipulation of MMP expression can be a powerful tool to aid in treating patients with chemo-resistant cancers. However, much still needs to be done to bring the solution from bench to bedside.

Different domains of dengue research in the Philippines: A systematic review and meta-analysis of questionnaire-based studies

Background

Dengue is the most rapidly spreading mosquito-borne viral disease of humans worldwide, including southeast Asia region. This review provides a comprehensive overview of questionnaire-related dengue studies conducted in the Philippines and evaluates their reliability and validity in these surveys.

Methods

A review protocol constructed by a panel of experienced academic reviewers was used to formulate the methodology, research design, search strategy and selection criteria. An extensive literature search was conducted between March–June 2020 in various major electronic biomedical databases including PubMed, EMBASE, MEDLINE and ScienceDirect. A systematic review and meta-analysis (PRISMA) were selected as the preferred item reporting method.

Results

Out of a total of 34 peer-reviewed dengue-related KAP studies that were identified, 15 published from 2000 to April 2020 met the inclusion criteria. Based on the meta-analysis, a poor mean score was obtained for each of knowledge (68.89), attitude (49.86) and preventive practice (64.69). Most respondents were equipped with a good knowledge of the major clinical signs of dengue. Worryingly, 95% of respondents showed several negative attitudes towards dengue prevention, claiming that this was not possible and that enacting preventive practices was not their responsibility. Interestingly, television or radio was claimed as the main source of gaining dengue information (range 50–95%). Lastly, only five articles (33.3%) piloted or pretested their questionnaire before surveying, of which three reported Cronbach’s alpha coefficient (range 0.70 to 0.90).

Conclusion

This review indicates that to combat the growing public health threat of dengue to the Philippines, we need the active participation of resident communities, full engagement of healthcare personnel, promotion of awareness campaigns, and access to safe complementary and alternative medicines. Importantly, the psychometric properties of each questionnaire should be assessed rigorously.

Development and validation of a structured survey questionnaire on knowledge, attitude, preventive practice, and treatment-seeking behaviour regarding dengue among the resident population of Sabah, Malaysia: an exploratory factor analysis

BACKGROUND

Several studies have reported a significant association of knowledge, attitude and preventive practice (KAP) regarding dengue infection among community's resident in endemic areas. In this study we aimed to assess and develop a reliable and valid KAP survey on the subject of dengue that is suitable for the resident population of Sabah, Malaysia.

METHODS

A community-based cross-sectional study was conducted from October 2019 to February 2020 involving 468 respondents. Information on the socio-demographic characteristics of the participants (six items), their KAP (44, 15 and 18 items on knowledge, attitude and practice, respectively) and treatment-seeking behaviour (five items) towards dengue was collected using a structured questionnaire. Data analysis was performed using SPSS and R software in the R Studio environment. The knowledge section was analysed by two-parameter logistic item response theory (2-PL IRT) using ltm package. The construct validity and reliability of items for sections on attitude, practice and treatment-seeking behaviour were analysed using psy package.

RESULTS

For the knowledge section, only 70.5% (31/44) of items were within or close to the parameter acceptable range of -3 to + 3 of difficulty. In terms of discrimination, 65.9% (29/44) of items were within or close to the acceptable range of 0.35 to 2.5, and 24 items (54.5%) failed to fit the 2-PL IRT model (P < 0.05) after assessing by goodness-of-fit analysis. Only eight items were reliable and retained in the attitude section with a Kaiser-Meyer-Olkin (KMO) test value of > 0.7, while based on the communalities, 11 items in the attitude section were excluded due to very low h2, factor loading values and low correlation with the total (< 0.5). The practice section was found suitable for factor analysis because the KMO value was > 0.7. The communalities of the practice section showed that seven items had low h2 values (< 0.3), which were therefore excluded from further analysis, and only 11 items were retained.

CONCLUSIONS

The KAP items retained in the final version of the survey were reliable and valid to be use as a questionnaire reference when conducting future similar studies among the population of Sabah.

Molecular Regulatory Roles of Long Non-coding RNA HOTTIP: An Overview in Gastrointestinal Cancer

Gastrointestinal (GI) cancers presented an alarmingly high number of new cancer cases worldwide and highly characterised with poor prognosis. The poor overall survival is mainly due to late detection and emerging challenges in treatment, particularly chemoresistance. Thus, the identification of novel molecular targets in GI cancer is highly regarded as the main focus. Recently, long non-coding RNAs (lncRNAs) have been discovered as a potential novel molecular target for combating cancer, as it is highly associated with carcinogenesis and has a great impact on cancer progression. Amongst lncRNAs, HOTIIP has demonstrated a prominent oncogenic regulation in cancer progression, particularly in GI cancers, including oesophageal cancer, gastric cancer, hepatocellular carcinoma, pancreatic cancer and colorectal cancer. This review aimed to present a focused update on the regulatory roles of HOTTIP in GI cancer progression and chemoresistance, as well as deciphering the associated molecular mechanisms underlying their impact on cancer phenotypes and chemoresistance and the key molecules involved. It has been reported that it regulates the expression of various genes and proteins in GI cancers that impacts on the cellular functions, including proliferation, adhesion, migration and invasion, apoptosis, chemosensitivity and tumour differentiation. Furthermore, HOTTIP was also discovered to have a higher diagnostic value as compared to existing diagnostic biomarkers. In overall, HOTTIP has presented itself as a novel therapeutic target and potential diagnostic biomarker in the development of GI cancer treatment.

Long Noncoding RNA UCA1 in Gastrointestinal Cancers: Molecular Regulatory Roles and Patterns, Mechanisms, and Interactions

The rising trend of gastrointestinal (GI) cancer has become a global burden due to its aggressive nature and poor prognosis. Long noncoding RNAs (lncRNAs) have recently been reported to be overexpressed in different GI cancers and may contribute to cancer progression and chemoresistance. They are featured with more than 200 nucleotides, commonly polyadenylated, and lacking an open reading frame. LncRNAs, particularly urothelial carcinoma-associated 1 (UCA1), are oncogenes involved in regulating cancer progression, such as cell proliferation, invasion, migration, and chemoresistance, particularly in GI cancer. This review was aimed to present an updated focus on the molecular regulatory roles and patterns of lncRNA UCA1 in progression and chemoresistance of different GI cancers, as well as deciphering the underlying mechanisms and its interactions with key molecules involved, together with a brief presentation on its diagnostic and prognostic values. The regulatory roles of lncRNA UCA1 are implicated in esophageal cancer, gastric cancer, pancreatic cancer, hepatobiliary cancer, and colorectal cancer, where they shared similar molecular mechanisms in regulating cancer phenotypes and chemoresistance. Comparatively, gastric cancer is the most intensively studied type in GI cancer. LncRNA UCA1 is implicated in biological roles of different GI cancers via interactions with various molecules, particularly microRNAs, and signaling pathways. In conclusion, lncRNA UCA1 is a potential molecular target for GI cancer, which may lead to the development of a novel chemotherapeutic agent. Hence, it also acts as a potential diagnostic and prognostic marker for GI cancer patients.

Selective phytochemicals targeting pancreatic stellate cells as new anti-fibrotic agents for chronic pancreatitis and pancreatic cancer

Activated pancreatic stellate cells (PSCs) have been widely accepted as a key precursor of excessive pancreatic fibrosis, which is a crucial hallmark of chronic pancreatitis (CP) and its formidable associated disease, pancreatic cancer (PC). Hence, anti-fibrotic therapy has been identified as a novel therapeutic strategy for treating CP and PC by targeting PSCs. Most of the anti-fibrotic agents have been limited to phase I/II clinical trials involving vitamin analogs, which are abundant in medicinal plants and have proved to be promising for clinical application. The use of phytomedicines, as new anti-fibrotic agents, has been applied to a variety of complementary and alternative approaches. The aim of this review was to present a focused update on the selective new potential anti-fibrotic agents, including curcumin, resveratrol, rhein, emodin, green tea catechin derivatives, metformin, eruberin A, and ellagic acid, in combating PSC in CP and PC models. It aimed to describe the mechanism(s) of the phytochemicals used, either alone or in combination, and the associated molecular targets. Most of them were tested in PC models with similar mechanism of actions, and curcumin was tested intensively. Future research may explore the issues of bioavailability, drug design, and nano-formulation, in order to achieve successful clinical outcomes with promising activity and tolerability.

MicroRNA expression signature of methamphetamine use and addiction in the rat nucleus accumbens

Methamphetamine (METH) is a highly addictive psycho-stimulant that induces behavioral changes due to high level of METH-induced dopamine in the brain. Nucleus accumbens (NAc) plays an important role in these changes, especially in drug addiction. However, little is known about the underlying molecular mechanisms of METH-induced addiction. The objective of this study was to establish a behavioral model of METH use and addiction using escalating doses of METH over 15 days and to determine the global miRNA expression profiling in NAc of METH-addicted rats. In the behavioral study, the experimental rats were divided into 3 groups of 9 each: a control group, a single dose METH (5 mg/kg) treatment group and a continuous 15 alternate days METH (0.25, 0.5, 1, 2, 3, 4, 5 mg/kg) treatment group. Following that, six rats in each group were randomly selected for global miRNA profiling. Addiction behavior in rats was established using Conditioned Place Preference task. The analysis of the miRNA profiling in the NAc was performed using Affymetric microarray GeneChip® System. The findings indicated that a continuous 15 alternate days METH treatment rats showed a preference for the drug-paired compartment of the CPP. However, a one-time acute treatment with 5 mg/kg METH did not show any significant difference in preference when compared with controls. Differential profiling of miRNAs indicated that 166 miRNAs were up-regulated and 4 down-regulated in the chronic METH-treatment group when compared to controls. In comparing the chronic treatment group with the acute treatment group, 52 miRNAs were shown to be up-regulated and 7 were down-regulated. MiRNAs including miR-496-3p, miR-194-5p, miR-200b-3p and miR-181a-5p, were found to be significantly associated with METH addiction. Canonical pathway analysis revealed that a high number of METH addiction-related miRNAs play important roles in the MAPK, CREB, G-Protein Couple Receptor and GnRH Signaling pathways. Our results suggest that dynamic changes occur in the expression of miRNAs following METH exposure and addiction.

Paracrine IL-6 signaling mediates the effects of pancreatic stellate cells on epithelial-mesenchymal transition via Stat3/Nrf2 pathway in pancreatic cancer cells

BACKGROUND

We previously showed that pancreatic stellate cells (PSC) secreted interleukin (IL)-6 and promoted pancreatic ductal adenocarcinoma (PDAC) cell proliferation via nuclear factor erythroid 2 (Nrf2)-mediated metabolic reprogramming. Epithelial-mesenchymal transition (EMT) is a key process for the metastatic cascade. To study the mechanism of PDAC progression to metastasis, we investigated the role of PSC-secreted IL-6 in activating EMT and the involvement of Nrf2 in this process.

METHODS

Gene expression of IL-6 and IL-6Rα in PSC and PDAC cells was measured with qRT-PCR. The role of PSC-secreted IL-6, JAK/Stat3 signaling, and Nrf2 mediation on EMT-related genes expression was also examined with qRT-PCR. EMT phenotypes were assessed with morphological change, wound healing, migration, and invasion.

RESULTS

PSC expressed higher mRNA levels of IL-6 but lower IL-6Rα compared to PDAC cells. Neutralizing IL-6 in PSC secretion reduced mesenchymal-like morphology, migration and invasion capacity, and mesenchymal-like gene expression of N-cadherin, vimentin, fibronectin, collagen I, Sip1, Snail, Slug, and Twist2. Inhibition of JAK/Stat3 signaling induced by IL-6 repressed EMT and Nrf2 gene expression. Induction of Nrf2 activity by tert-butylhydroquinone (tBHQ) increased both EMT phenotypes and gene expression (N-cadherin, fibronectin, Twist2, Snail, and Slug) repressed by IL-6 neutralizing antibody. Simultaneous inhibition of Nrf2 expression with siRNA and Stat3 signaling further repressed EMT gene expression, indicating that Stat3/Nrf2 pathway mediates EMT induced by IL-6.

CONCLUSIONS

IL-6 from PSC promotes EMT in PDAC cells via Stat3/Nrf2 pathway.

GENERAL SIGNIFICANCE

Targeting Stat3/Nrf2 pathway activated by PSC-secreted IL-6 may provide a novel therapeutic option to improve the prognosis of PDAC.

Quantitation of methadone and metabolite in patients under maintenance treatment

Gas chromatography-mass spectrometry quantitative method was developed to monitor concentrations of methadone and its metabolite 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) in plasma and urine of patients. The developed method was simple, accurate and reproducible to quantify methadone and EDDP in plasma and urine samples in the concentration range of 15-1,000 and 50-2,000 ng/mL, respectively. The proposed analytical method was applied to plasma and urine samples obtained from 96 patients undergoing methadone maintenance treatment (MMT) with daily methadone doses of 2-120 mg/day. Urinary methadone excretion was observed to be significantly affected by pH, in which the ratio of methadone to EDDP was two times higher in acidic urine (P = 0.029). The findings of this study further enhance the guidelines for monitoring of methadone treatment among outpatients. Methadone-to-EDDP ratio in urine was found to be consistent at 24 and 4 h, hence suggesting the possibility that outpatients may be monitored with single urine sample in order to check for compliance. This study which provides data on peak concentrations of methadone and EDDP as well as the ratio of both compounds has added to the body of knowledge regarding pharmacokinetic properties of methadone among heroin-dependent patients under MMT.

Association of a functional FAAH polymorphism with methamphetamine-induced symptoms and dependence in a Malaysian population

AIM

FAAH is a membrane enzyme that terminates the activity of a large class of endogenous signaling lipids. Recent studies suggest that the FAAH Pro129Thr polymorphism is a common mutation in the FAAH gene that is significantly associated with drug-addictive traits. This study investigated the association of the Pro129Thr polymorphism of the FAAH gene with methamphetamine dependence, methamphetamine-induced psychosis, manic episodes and panic disorder in a Malaysian population.

MATERIALS & METHODS

This polymorphism was genotyped in 232 male methamphetamine-dependent subjects and in 241 male controls of four different ethnicities: Malay, Chinese, Kadazan-Dusun and Bajau. Intergroup statistical analyses were performed by using the χ(2)-square test and Fisher's exact test, where necessary. In cases of multiple comparisons, the Bonferroni correction was performed.

RESULTS

Our results indicated that the FAAH Pro129Thr polymorphism showed a significant association with risk of methamphetamine dependence in the pooled subjects (odds ratio [OR]: 2.017; p < 0.001) and in the Malay (OR: 2.829; p < 0.001) and Chinese (OR: 3.685; p < 0.001) groups. We also found an association of this polymorphism with episodes of methamphetamine-induced mania in the Malay group (OR: 2.836; p = 0.035). However, there was no association between this polymorphism and age of onset of drug use or the occurrence of methamphetamine-induced psychosis or of panic disorder.

CONCLUSION

Our findings suggest that the FAAH Pro129Thr polymorphism may contribute to methamphetamine dependence in the Malay and Chinese ethnic groups.

Cyanobacterial diversity and activity in modern conical microbialites

Modern conical microbialites are similar to some ancient conical stromatolites, but growth, behavior and diversity of cyanobacteria in modern conical microbialites remain poorly characterized. Here, we analyze the diversity of cyanobacterial 16S rRNA gene sequences in conical microbialites from 14 ponds fed by four thermal sources in Yellowstone National Park and compare cyanobacterial activity in the tips of cones and in the surrounding topographic lows (mats), respectively, by high-resolution mapping of labeled carbon. Cones and adjacent mats contain similar 16S rRNA gene sequences from genetically distinct clusters of filamentous, non-heterocystous cyanobacteria from Subsection III and unicellular cyanobacteria from Subsection I. These sequences vary among different ponds and between two sampling years, suggesting that coniform mats through time and space contain a number of cyanobacteria capable of vertical aggregation, filamentous cyanobacteria incapable of initiating cone formation and unicellular cyanobacteria. Unicellular cyanobacteria are more diverse in topographic lows, where some of these organisms respond to nutrient pulses more rapidly than thin filamentous cyanobacteria. The densest active cyanobacteria are found below the upper 50 μm of the cone tip, whereas cyanobacterial cells in mats are less dense, and are more commonly degraded or encrusted by silica. These spatial differences in cellular activity and density within macroscopic coniform mats imply a strong role for diffusion limitation in the development and the persistence of the conical shape. Similar mechanisms may have controlled the growth, morphology and persistence of small coniform stromatolites in shallow, quiet environments throughout geologic history.

Association of brain-derived neurotrophic factor (Val66Met) genetic polymorphism with methamphetamine dependence in a Malaysian population

Methamphetamine is a highly addictive psychostimulant that has surged in popularity worldwide in the last decade. Brain-derived neurotrophic factor (BDNF), a member of the neurotrophic factor family, is widely expressed in the adult mammalian brain and plays an important role in the long-term survival, differentiation, and outgrowth of neurons. Previous studies suggested that the BDNF gene may be involved in the mechanisms underlying substance dependence. This study investigated the association of the BDNF gene Val66Met polymorphism with methamphetamine dependence and with psychosis in a Malaysian population with different ethnicities. The BDNF Val66Met polymorphism was genotyped by PCR-RFLP in 186 male methamphetamine-dependent subjects and in 154 male controls of four different ethnicities, namely, Malay, Chinese, Kadazan-Dusun, and Bajau. Our results showed that the distribution of the BDNF Val66Met genotype in Chinese subjects with methamphetamine dependence (OR=2.6, p=0.015) and methamphetamine psychosis (OR=0.2, p = 0.034) were significant compared with controls. The frequency of the 66Val allele in methamphetamine-dependent subjects was higher than that in the control group, suggesting that the 66Val carriers are more susceptible to methamphetamine dependence. However, 66Val allele frequency in other ethnicities was not significantly different from the controls. The results of the study also showed that in the Chinese methamphetamine-dependent subjects, there was a difference in allele frequency when comparing those who developed psychosis and those who did not. Our findings suggest that the BDNF Val66Met polymorphism may contribute to methamphetamine dependence and psychosis in the Chinese population but not in other Malaysian ethnicities.

Formation and stability of oxygen-rich bubbles that shape photosynthetic mats

Gas release in photic-zone microbialites can lead to preservable morphological biosignatures. Here, we investigate the formation and stability of oxygen-rich bubbles enmeshed by filamentous cyanobacteria. Sub-millimetric and millimetric bubbles can be stable for weeks and even months. During this time, lithifying organic-rich laminae surrounding the bubbles can preserve the shape of bubbles. Cm-scale unstable bubbles support the growth of centimetric tubular towers with distinctly laminated mineralized walls. In environments that enable high photosynthetic rates, only small stable bubbles will be enclosed by a dense microbial mesh, while in deep waters extensive microbial mesh will cover even larger photosynthetic bubbles, increasing their preservation potential. Stable photosynthetic bubbles may be preserved as sub-millimeter and millimeter-diameter features with nearly circular cross-sections in the crests of some Proterozoic conical stromatolites, while centrimetric tubes formed around unstable bubbles provide a model for the formation of tubular carbonate microbialites that are not markedly depleted in (13)C.

Basic cardiac life support education for non-medical hospital employees

BACKGROUND

The International Liaison Committee on Resuscitation (ILCOR) recommends that strategies should be implemented that promote cardiopulmonary resuscitation (CPR) training in the workplace. Non-medical employees at a hospital were therefore trained to conduct basic life support (BLS). Subject background information, test results and survey findings were examined and factors affecting BLS skill acquisition were studied.

METHODS

Of 1432 non-medical employees at a hospital trained to conduct BLS, 880 agreed to participate in the survey. The training course consisted of a single session of 3 h of lectures, practice and testing. Skill acquisition was assessed using a 13-item skill checklist and a 5-point overall competency scale. The effects of age, gender, type of job, educational status, a previous history of CPR training and level of subject-perceived training difficulty were examined.

RESULTS

According to total checklist scores, subjects achieved a mean (SD) score of 8.66 (3.57). 22.3% performed all 13 skills. Based on 5-point overall competency ratings, 43.7% of subjects were rated as "competent", "very good" or "outstanding". Age (<40 years and >or=40 years) was the only factor that significantly affected skill acquisition (skill acquisition by those >or=40 years of age was poorer than by those aged <40 years).

CONCLUSION

Traditional BLS training is less effective in individuals aged >or=40 years.

Smad4 expression in gastric adenoma and adenocarcinoma: frequent loss of expression in diffuse type of gastric adenocarcinoma

Smads are signal transducers for the members of the TGF-beta superfamily. Of these Smads, Smad4 is essential for TGF-beta signaling. The purpose of this study was to elucidate Smad4 expression and localization in 65 gastric adenomas, 49 intestinal-type and 39 diffuse type of gastric adenocarcinomas (including 12 cases of fresh frozen tissue) using Real-time RT-PCR and immunohistochemistry. Real-time RT-PCR showed that intestinal type gastric adenocarcinomas have higher Smad4 mRNA expression than diffuse type gastric adenocarcinomas. Immunohistochemical stain for Smad4 revealed that expression of Smad4 was significantly lower in diffuse-type gastric adenocarcinoma than intestinal-type gastric adenocarcinomas. Also, higher Smad4 protein expression in intestinal type gastric adenocarcinomas than overall gastric adenoma was noted. The rate of reduced Smad4 expression was higher in advanced gastric cancer than early gastric cancer. These results suggest that Smad4 might play different roles in human gastric carcinogenesis, especially between intestinal type and diffuse type of gastric adenocarcinoma.

Correlation of Ultrasonographic Findings and Pathologic Prognostic Predictions in Breast Cancer

PURPOSE

Increased technologic capabilities have allowed for the expanded use of ultrasound beyond simple differentiation of a lesion as solid versus cystic nature, allowing us to classify lesions into various categories based on a number of descriptive features. The purpose of this study was to investigate whether to predict the preoperative prognosis of breast cancer through the correlation between ultrasonographic images and the grade of malignancy.

MATERIALS AND METHODS

The patient population for this study consisted of 107 patients with infiltrative ductal carcinoma who were evaluated using ultrasound technology. Ultrasonographic findings were divided as follows: Type I, round or oval shape and regular border; Type II, partially round or oval shape and partially irregular border; and Type III, irregular shape and irregular border.

RESULTS

1. The frequency of grade 1 (G1) was significantly higher in the Type I group than the othergroups. 2. In the 2.0 cm sized mass, the lymph node metastasis rate was significantly lower in the Type I group than the other groups. 3. In all the groups, Estrogen receptor (ER) positivity was insignificant regardless of tumor size and type. 4. In the 2.0 cm sized mass, c-erbB-2 positivity was significantly lower in the Type I than the other groups. There was no clear difference among the three groups in tumors greater than 2.0 cm in size.

CONCLUSION

These results show that our classification of ultrasonographic images reflect the grade of malignancy in terms of clinicopathological features in breast cancers less than 2.0 cm in size. Therefore, ultrasonographic findings may help predict the preoperative prognosis in T1 size breast cancer, although further study is required.

Recovery of replication-competent virus from CD4 T cell reservoirs and change in coreceptor use in human immunodeficiency virus type 1-infected children responding to highly active antiretroviral therapy

Highly active antiretroviral therapy (HAART) suppresses plasma viremia in most patients with human immunodeficiency virus (HIV) infection. Prospective study of HIV-infected children (n=27) shows that, in 8 of 12 who responded to HAART (>/=0.5 log reduction in plasma HIV RNA), HAART restricted the number of coreceptors used by the predominant HIV isolate (mean number of coreceptors used at baseline was 4, vs. 1 coreceptor used at 6 months after treatment). This decrease was most striking in 6 of 8 children whose HIV coreceptor tropism changed from X4-tropic at baseline to R5-tropic. In 6 of 10 children tested, with plasma HIV RNA levels of <50 copies/mL, R5-tropic virus was isolated from CD4 T cell reservoirs. All the responding children had a significant increase in naive CD4 T cells (P<.05). These results show that persistent HIV T cell reservoirs are present in children and that HAART may influence the number and type of coreceptors used by the predominant virus isolate.

Antiperistaltic ileostomy using the long terminal ileal segment

PURPOSE

This study was undertaken to determine whether reversed terminal ileal segments can be used to decrease ileostomy output in patients who have undergone total proctocolectomy and ileostomy for ulcerative colitis or familial adenomatous polyposis.

METHODS

An approximately 25-cm length of terminal ileum was reversed in an antiperistaltic manner, and the new terminal ileal end was used for the ileostomy constructed in the usual manner. Six patients underwent this procedure and were compared with six patients who had conventional total proctocolectomy and ileostomy. Variables studied included weight of ileostomy output and the weight of the filtered fluid component. Data were obtained on seven different occasions during a two-month period beginning three months after the operation. Analysis was done using Student's t-test.

RESULTS

There was a statistically significant decrease in the weight of the average 24-hour ileostomy effluent in those patients undergoing reversed antiperistaltic loop procedures. There was also a statistically significant decrease in the filterable liquid proportions.

CONCLUSIONS

The antiperistaltic ileostomy is effective in reducing the daily amount of ileostomy effluent and facilitates stoma care, owing to its diminished liquid component.

Identification of levels of maternal HIV-1 RNA associated with risk of perinatal transmission. Effect of maternal zidovudine treatment on viral load

OBJECTIVE

To determine if there are levels of human immunodeficiency virus type 1 (HIV-1) associated with a high or low risk of perinatal transmission and to ascertain the mechanism by which zidovudine treatment reduces perinatal transmission.

DESIGN

A nonrandomized prospective cohort study.

SETTING

University medical center and two general hospital affiliates from May 1989 to September 1994.

PATIENTS

Ninety-two HIV-1-seropositive women (95 pregnancies) and their 97 infants.

INTERVENTION

Forty-two mothers (43 pregnancies) received zidovudine therapy during pregnancy and/or during labor and delivery. Eleven infants received prophylactic zidovudine for the first 6 weeks after delivery.

MAIN OUTCOME MEASURE

HIV-1 infection status of the infant.

RESULTS

Twenty of the 97 infants were perinatally infected with HIV-1. Transmitting mothers were more likely to have plasma HIV-1 RNA levels higher than 50000 copies per milliliter at delivery than nontransmitting mothers (15 [75.0%] of 20 transmitters vs four [5.3%] of 75 nontransmitters; P < .001). None of the 63 women with less than 20000 HIV-1 RNA copies per milliliter transmitted. Twenty-two women treated with open-label oral zidovudine during gestation showed an eightfold median decrease in plasma RNA levels (median [25th and 75th percentile], 43043 [5699 and 63053] copies per milliliter before zidovudine vs 4238 [603 and 5116] HIV-1 RNA copies per milliliter at delivery; P < .001) and none transmitted. Four zidovudine-treated women with high HIV-1 levels transmitted despite the presence of zidovudine-sensitive virus in vitro in both the mothers and their infants.

CONCLUSIONS

Maternal HIV-1 RNA levels were highly predictive of perinatal transmission risk and suggest that certain levels of virus late in gestation and/or during labor and delivery are associated with both a high risk and a low risk of transmission. Our results also suggest that zidovudine exerts a major protective effect by reducing maternal HIV-1 RNA levels prior to delivery and that further strategies are needed to prevent perinatal transmission in women with high or increasing virus levels and/or zidovudine-resistant virus.

Correlation of clinical progression in human immunodeficiency virus-infected children with in vitro zidovudine resistance measured by a direct quantitative peripheral blood lymphocyte assay

A rapid method for determination of zidovudine resistance was developed and results were correlated with clinical outcome in human immunodeficiency virus (HIV)-infected children. The zidovudine susceptibilities of HIV-1 isolates from 34 children were determined through a direct quantitative peripheral blood lymphocyte assay and compared with results of the AIDS Clinical Trials Group resistance assay. Patients' peripheral blood lymphocytes were 5-fold diluted and cocultured with donor lymphocytes and varying concentrations of zidovudine. Isolates were defined as sensitive if inhibited by < or = 1.0 microM zidovudine and resistant at > 1.0 microM. Children (n = 21) with zidovudine-resistant virus had greater evidence of disease progression than did those with zidovudine-sensitive virus (n = 11) as demonstrated by failure to thrive (57% vs. 9%, P = .01) and opportunistic infections (48% vs. 0, P = .006). This assay may be useful as a screening tool for development of clinically relevant zidovudine resistance.

Quality of life in adult survivors of lung, colon and prostate cancer

In a cross-sectional study design, a disease free sample of 57 lung, 117 colon, and 104 prostate cancer survivors who represented short, intermediate and long-term survivors completed a detailed assessment of quality of life (QOL) and rehabilitation needs using the CAncer Rehabilitation Evaluation System (CARES). Demographic and medical data, social support, and a global QOL rating were also assessed. Lung cancer patients showed no differences in QOL with respect to their period of survival. QOL improved for survivors of colon cancer as they lived for longer periods, but declined with time for survivors of prostate cancer. The best predictor of QOL for all groups was KPS, although other variables such as type of hospital, gender, and work status were predictive for survivors of colon cancer. For survivors of prostate cancer comorbidity with other medical illnesses, time since diagnosis and comorbidity due to psychiatric difficulties were predictive of QOL. All groups had significant rehabilitation problems in the domains of physical, psychosocial, sexual, medical interaction, and marital relationships. Lung cancer survivors had more problems than the other cancer survivors. We conclude that patients who survive cancer do not return to a state of normal health. They demonstrate a variety of difficulties with which they must cope as they continue to survive. Greater efforts need to be made early in diagnosis and treatment to understand rehabilitation problems and target interventions in the hope of reducing later sequelae.

Predicting psychosocial risk in patients with breast cancer

Breast cancer is the most common neoplasm in North American women. The psychosocial impact of breast cancer has been extensively studied, and a number of investigators have attempted to characterize women who are at high risk for increased psychosocial morbidity. Although a detailed interview performed by a professional is the clinical standard for psychosocial assessment, such interviews are usually time-consuming and expensive, and thus are rarely performed. This study was designed to develop a strategy for the rapid identification of newly-diagnosed breast cancer patients at risk for psychosocial morbidity. A sample of 227 newly diagnosed breast cancer patients were interviewed systematically by a clinical social worker and were subsequently classified for risk of psychosocial distress in the year after diagnosis. In addition, these women completed a battery of standardized instruments designed to assess quality of life, rehabilitation needs and psychological distress. A logistic regression procedure was used to examine a wide range of variables for their ability to correctly classify the risk of psychosocial distress in this sample. The final model included the Cancer Rehabilitation Evaluation System (CARES) Psychosocial Summary Scale, the Karnofsky Performance Status score and age as the best predictors of psychosocial risk. Subsequently these three variables were used to construct a clinically usable risk prediction model. Additional research should be performed to validate this predictive model.

Exploring the influence of multiple variables on the relationship of age to quality of life in women with breast cancer

This paper explores the relationship between age, psychosocial status and quality of life in a community based sample (n = 229) of newly-diagnosed breast cancer patients. A casement display methodology is used to examine the influence of demographic and medical variables on the outcome variables of interest (psychosocial status and quality of life) and their relationship to age. Based on the literature, a positive relationship between age and psychosocial status was predicted, but the relationship between age and quality of life was uncertain. For the whole sample, a weakly positive relationship between age and measures of psychosocial status and quality of life was observed. In the exploratory studies using the casement plots, the positive relationship between age and quality of life was most strong and significant in married women and in women who had received segmental mastectomy. Among sub-groups examined according to marital status and type of surgery, a positive relationship between age, psychosocial status and quality of life was observed only in married women who received segmental mastectomy. Additional preliminary observations were made about the relationship of household income and age to the outcome variables being studied. The casement plot methodology permits the simultaneous evaluation of multiple variables as a preliminary step before hypothesis development and should be considered when complex clinical problems are being evaluated.

The CARES: a generic measure of health-related quality of life for patients with cancer

In spite of the prevalence of neoplastic disorders as a cause of chronic illness, very few of the currently available generic measures of health-related quality of life or health status have been utilized with cancer patients. In this paper we reviewed our studies with the Cancer Rehabilitation Evaluation System (CARES), a cancer-specific measure of rehabilitation needs and quality of life. We present data to demonstrate that the CARES is a generic measure of health-related quality of life, suitable for use in the many different diseases called cancer. The data that form the basis for this paper were collected during a decade of research on the CARES. This paper represents the first discussion of the performance of the CARES across separate cancer sites and phases of the disease. In addition, we demonstrated that the CARES is responsive to changes in health-related quality of life over time. Finally, we will discuss the application of the CARES in clinical and research settings.