Antimicrobial Therapy: An Important Risk for Acquired Aplastic Anemia

Background: Aplastic anemia although a rare hematological disorder but it is associated with poor prognosis and high mortality. It is a matter of greater public health concern for the Asian population with prevalence 3 times greater than other part of the globe. Exposures of specific drugs, chemicals and others have been connected with an AA etiology. We aimed to examine the association of antimicrobial drugs exposures with AA. Methods: We conducted a case-control study in Karachi, Pakistan, selecting the patients with two blood lineages depressed on bone marrow biopsy as the cases while patients without any hematological disorder as controls. For each case four age-sex matched control were enrolled. Information associated to socio-demographics and exposure to antibiotics was collected on a questionnaire during personal interview. Results: We identified 191 cases with an age range of 1-66 years and 696 controls. Predominant participants were male (67%), female being 33%. Antimicrobial drugs were used by 49.74% of aplastic anemia cases whereas the use was reported in 29.31% controls. Beta-lactam antibiotics, chloramphenicol, macrolides, Trimethoprim/Sulfamethoxazole, tetracycline and others were the drug categories evaluated. Conclusion: Antimicrobials were reported to be used more frequently in aplastic anemia cases as compared to their normal controls

An Epidemic of Pediatric HIV From Reuse of Infusion Equipment in Pakistan

BACKGROUND

From April to June 2019, a total of 909 new HIV infections were identified in Larkana, Pakistan; 86% was children younger than 15 years. To identify the possible transmission links in this outbreak, a case-control study was conducted in June 2019.

METHODS

For cases, we selected a systematic random sample of 100 HIV-positive children from the screening list. We chose 2 age-matched and sex-matched controls from the neighborhood of each HIV-positive case. All selected children were tested using the World Health Organization-approved rapid diagnosis test algorithm. We interviewed the parents of each selected child about previous exposures to parenteral treatment and compared exposures of case and control children using conditional logistic regression.

RESULTS

The ages of the selected children ranged from 1 month to 10 years. More than 90% of both HIV+ and HIV- children had received outpatient health care from MBBS-qualified private physicians. Eighty-three percent of HIV+ children versus 46% of HIV- children had received health care from one private physician [adjusted odds ratio (aOR) = 29, 95% confidence interval (95% CI): 10 to 79]. Intravenous infusions during the last outpatient visit were reported by 29% of case versus 7% of controls (aOR 57, 95% CI: 2.9 to >1000), whereas no case children and 17% of control children had received only intramuscular injections (aOR 0, 95% CI: 0 to 41). Among cases, 94% had been given infusions through a drip set compared with 85% of control children (aOR = 7.7, 95% CI: 2.3 to 26). Infusions had been administered with reused IV drip sets in 70% of cases compared with 8% of controls (aOR = 197, 95% CI: 16 to 2400).

DISCUSSION

Private physicians reusing intravenous drip sets to treat outpatients seen in private practice were responsible for this HIV epidemic. Mapping and regulation of private practitioners were suggested.

Emergence of a febrile illness of unknown causes among the population and visitors of Upper Egypt

This is a fictional case study for training that encourages participants to interact and apply theory into practice. A febrile illness of unknown cause that occurred in Upper Egypt in 2002 was chosen for the events. The location of Aswan was selected to define the climate, topography, and location with the characteristics that support the events. Data obtained from applied research work in Egypt was included. The case study deals with the incidence of severe cases of fever of unknown origin accompanied by neurological and intestinal symptoms, as well as a high percentage of deaths. Most of the symptoms appear in people with direct contact with farm animals especially equines and birds, or those who were near waterways, either tourism workers or tourists. Most of the infected cases or deaths have accumulated in Aswan and some in the neighbouring governorates. This case study focusses on the steps taken during an outbreak investigation, and deals with investigative challenges as well as concepts of biosafety and biosecurity.

Outbreak investigation of an unknown gastrointestinal illness in District Victoria, Country Mala, 2016

This case study is based on an outbreak investigation conducted by multisectoral team from animal and public health offices in Kaktong (a remote village in Zhemgang District Bhutan) during July-September 2010. This outbreak caused by ingestion of infected cow meat which had died after a brief illness (bleeding of unclotted blood from nostrils). The owner of the affected cow had opened the carcass and dressed the meat, which he shared or sold within the village for human consumption. It simulates an epidemiological investigation including active and passive case finding, descriptive and analytical epidemiology, laboratory confirmation, risk communication with implementation of control measures. This case study is designed for the training of front-line public health professional, basic, intermediate and advanced level field epidemiology trainees. The case study will build the capacity of the trainees regarding investigating illnesses caused by animal-human interface.

An Investigation of Selected Socio-Demographic Factors with Aplastic Anemia in Pakistan: A Case-Control Study

Introduction

In Pakistan, the incidence rate of aplastic anemia is 3.5 cases/million. The associated risk factors are exposure to pesticides, chemicals, and some drugs. The link between aplastic anemia and socio-demographic factors is debatable.

Purpose

We conducted this study to investigate the role of socio-economic and -demographic factors with aplastic anemia.

Methodology

A total of 191 lab-confirmed incident cases of aplastic anemia were identified from the tertiary hospital of Karachi-Pakistan in between 2015 and 2018. Age and gender-matched 694 controls were randomly selected from the same institute admitted or visited for other non-neoplastic conditions. Socio-demographic and exposure information was gathered using a data collection form. Adjusted odds ratios (aORs) and 95% confidence intervals (CIs) were computed for selected socio-demographic factors.

Results

Among socio-demographic factors, significant associations of aplastic anemia risk emerged for illiteracy (aOR: 2.3; 1.5; 3.5) occupation (any type) (aOR: 2.1; 1.7; 2.5), living in rural environments (aOR: 2.9; 1.9; 4.2). The odds of aplastic anemia increased with the age group 31–50 years (aOR: 1.8; 1.7; 3.5) and >50 years (aOR: 2.5; 2.1; 4.2). We observed no association of income with the risk of aplastic anemia.

Conclusion

This study highlights the importance of socio-demographic factors as a risk factor for the development of aplastic anemia in the population of Pakistan. In order to reduce disease incidence, health education program and use of personal protective equipment and organization of screening camps in high-risk population is warranted.

The Relationship of Drug Therapy to Aplastic Anemia in Pakistan: A Hospital-Based Case Control Study

Introduction

Drug-induced aplastic anemia has long been a menacing outcome of modern pharmacotherapy. The incidence of idiosyncratic, drug-induced aplastic anemia varies depending on the genetic susceptibility and the associated drug. Only scarce studies have explained the epidemiology and actual incidence of this reaction.

Purpose

The aim of the study was to establish the association between drugs and aplastic anemia.

Methods

A case-control study was conducted with 191 cases and 696 controls at a tertiary hospital for blood diseases in Karachi-Pakistan. Cases were patients of aplastic anemia diagnosed through bone marrow biopsy. The controls did not have either AA or chronic diseases. Each case was paired with four sex and age group match controls. Cases and controls were compared with respect to the drugs used. Univariate and multivariate analysis were performed in order to delineate the association.

Results

Median age of the study-participants was 27 years (04-69 years). The majority 84 (44%) were from age group 16 to 30 years. The male-to-female ratio was 2:1. Among study participants, various drugs were significantly associated with aplastic anemia. Treatment of epilepsy with carbamazepine showed a positive association (OR=2.7, 95% C.I, 1.0-6.8). An increased risk of aplastic anemia was noted with exposure to thiazide (OR=3.1, 95% C.I, 1.3-7.4) and mebendazole (OR=3.7, 95% C.I, 1.5-9.2). However, risks were not increased with chloramphenicol, trimethoprim/sulfamethoxazole, benzodiazepines, antihistamines, oral contraceptives, and herbal medicine.

Conclusion

This large-scale case-control study provide association of aplastic anemia with exposure to carbamazepine, thiazides and mebendazole in population of Pakistan. Patients should be monitored with complete blood indices for early detection of drug toxicity.

Pesticides and Chemicals as Potential Risk Factors of Aplastic Anemia: A Case-Control Study Among a Pakistani Population

Introduction

Aplastic anemia is a rare and potentially life-threatening hematological disorder with incidence of 1.4 to 14 cases/million. It is associated with exposures to certain environmental chemicals, drugs and infections. The objective was to investigate the association of illness with family history of aplastic anemia, exposure to pesticides and chemicals.

Methodology

A hospital-based case–control study (191 cases, 696 controls) was conducted from 1st January 2015 to 31st December 2018 in Karachi, Sindh. Cases were patients with diagnosis of aplastic anemia confirmed with bone marrow biopsy. Controls neither had aplastic anemia nor other hematological chronic diseases. An in-person interview was conducted to collect demographic information, family history of aplastic anemia, and history of pesticide and chemical exposure. The adjusted odds ratios (aOR) with 95% confidence intervals (CI) were estimated via SPSS v22.

Results

A total of 191 confirmed aplastic anemia cases were selected. Mean age was 29 years (range: 4–69) and predominantly there were males 129 (67.5%). The majority, 84 (44.0%), of the cases were aged 16–30 years. In multivariate analysis models, the significant associations were observed between aplastic anemia with family history of aplastic anemia (aOR=13.3, 95% C.I 3.66–48.50), exposure to pesticides (aOR=2.1, 95% C.I 1.23–3.61) and chemicals (aOR=3.6, 95% C.I 2.06–6.34).

Conclusion

This study observed a significant association of aplastic anemia with family history of aplastic anemia, exposure to pesticide and insecticide exposure. However, to establish this connection, further longitudinal studies are warranted.

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Morbidity and Mortality Associated with Typhoid Fever Among Hospitalized Patients in Hyderabad District, Pakistan, 2017-2018: Retrospective Record Review

BACKGROUND

Hyderabad, Pakistan, was the first city to witness an outbreak of extensively drug resistant (XDR) typhoid fever. The outbreak strain is resistant to ampicillin, chloramphenicol, trimethoprim-sulfamethoxazole, fluoroquinolones, and third-generation cephalosporin, thus greatly limiting treatment options. However, despite over 5000 documented cases, information on mortality and morbidity has been limited.

OBJECTIVE

To address the existing knowledge gap, this study aimed to assess the morbidity and mortality associated with XDR and non-XDR Salmonella serovar Typhi infections in Pakistan.

METHODS

We reviewed the medical records of culture-confirmed typhoid cases in 5 hospitals in Hyderabad from October 1, 2016, to September 30, 2018. We recorded data on age, gender, onset of fever, physical examination, serological and microbiological test results, treatment before and during hospitalization, duration of hospitalization, complications, and deaths.

RESULTS

A total of 1452 culture-confirmed typhoid cases, including 947 (66%) XDR typhoid cases and 505 (34%) non-XDR typhoid cases, were identified. Overall, ≥1 complications were reported in 360 (38%) patients with XDR typhoid and 89 (18%) patients with non-XDR typhoid (P<.001). Ileal perforation was the most commonly reported complication in both patients with XDR typhoid (n=210, 23%) and patients with non-XDR typhoid (n=71, 14%) (P<.001). Overall, mortality was documented among 17 (1.8%) patients with XDR S Typhi infections and 3 (0.6%) patients with non-XDR S Typhi infections (P=.06).

CONCLUSIONS

As this first XDR typhoid outbreak continues to spread, the increased duration of illness before hospitalization and increased rate of complications have important implications for clinical care and medical costs and heighten the importance of prevention and control measures.

Risk Factors of Extensively Drug Resistant Typhoid Fever Among Children in Karachi: Case-Control Study

Background

Extensively drug resistant typhoid fever (XDR-TF) has been responsible for an ongoing outbreak in Pakistan, which began in November 2016.

Objective

This study aimed to determine the risk factors associated with XDR-TF.

Methods

This age- and sex-matched case-control study was conducted during May-October 2018 in Karachi. All patients with XDR-TF were identified from the laboratory-based surveillance system data. Cases included patients aged <15 years living in Karachi with culture-positive Salmonella enterica serovar Typhi with resistance to chloramphenicol, ampicillin, trimethoprim/sulfamethoxazole, fluoroquinolones, and third-generation cephalosporins. Age- and sex-matched controls included children free from the symptoms of TF, aged under 15 years, and residing in Karachi. All controls were recruited from among those who attended outpatient clinics.

Results

A total of 75 cases and 75 controls were included in this study. On univariate analysis, the odds of having XDR-TF were 13-fold higher among participants who used piped municipal water than among those who did not (odds ratio [OR] 12.6, 95% CI 4.1-38.6). The use of bore water was significantly associated with XDR-TF (OR 5.1, 95% CI 1.4-19.0). Cases were more likely to report eating French fries with sauce (OR 13.5, 95% CI 3.9-47.0) and poppadum (OR 3.4, 95% CI 1.7-6.7) from street vendors than controls. Boiling water at home was negatively associated with XDR-TF (OR 0.3, 95% CI 0.2-0.7). On multivariate analysis, 2 factors were independently associated with XDR-TF. Using piped municipal water (OR 10.3, 95% CI 3.4-30.4) and eating French fries with sauce from street vendors (OR 8.8, 95% CI 2.1-36.2) were significantly associated with an increased odds of XDR-TF.

Conclusions

Community water supply and street food eating habits were implicated in the spread of the superbug S typhi outbreak, which continues to grow in Karachi. Therefore, it is recommended to improve the community water supply to meet recommended standards and to develop a policy to improve the safety of street food. In addition, health authorities are required to conduct mass vaccination for TF among high-risk groups.

Molecular characterization of multidrug-resistance in Gram-negative bacteria from the Peshawar teaching hospital, Pakistan

Extended-spectrum β-lactamases, carbapenemases, 16S rRNA methylases conferring pan-drug aminoglycoside resistance and colistin resistance were investigated among Gram-negative bacteria recovered from clinical samples (infections) from 200 individuals hospitalized at the Khyber Teaching Hospital of Peshawar, north Pakistan, from December 2017 to March 2018. Out of 65 isolates recovered, 19% were carbapenem resistant and 16% carried a bla_NDM-1 gene, confirming the widespread distribution of NDM producers in this country. The association of the NDM carbapenem-resistance determinant, together with the extended-spectrum β-lactamase CTX-M-15 and 16S rRNA methylases, was frequent, explaining the multidrug-resistance pattern observed. All isolates remained susceptible to colistin.

Molecular characterization of Staphylococcus aureus isolates causing skin and soft tissue infections in patients from Malakand, Pakistan

Comparatively few studies have been published describing Staphylococcus aureus/MRSA epidemiology in Central Asia including Pakistan. Here, we report the genotyping of Staphylococcus aureus strains (that include both methicillin-susceptible and methicillin-resistant Staphylococcus aureus) from community- and hospital-acquired skin and soft-tissue infections in a tertiary care hospital in the Malakand district of the Khyber Pakhtunkhwa Province of Pakistan. Forty-five isolates of Staphylococcus aureus were characterized by microarray hybridization. Twenty isolates (44 %) were MRSA, whereas 22 (49 %) were PVL-positive. Fourteen isolates (31 %) harboured both mecA and PVL genes. The dominant clones were CC121-MSSA (n = 15, 33 %) and the PVL-positive "Bengal Bay Clone" (ST772-MRSA-V; n = 13, 29 %). The PVL-positive CC8-MRSA-IV strain "USA300" was found once. The pandemic ST239-MRSA-III strain was absent, although it has previously been observed in Pakistan. These observations require a re-assessment of schemes for initial antibiotic therapy to cover MRSA and they emphasise the need for a rapid and non-molecular test for PVL.

Hydroxyapatite ceramic-coated femoral components in young patients followed up for 17 to 25 years: an update of a previous report

This study reports the results of 38 total hip arthroplasties (THAs) in 33 patients aged < 50 years, using the JRI Furlong hydroxyapatite ceramic (HAC)-coated femoral component. This represents an update of previous reports of the same cohort at ten and 16 years, which were reported in 2004 and 2009, respectively. We describe the survival, radiological and functional outcomes at a mean follow-up of 21 years (17 to 25). Of the surviving 34 THAs, one underwent femoral revision for peri-prosthetic fracture after 21 years, and one patient (one hip) was lost to follow-up. Using aseptic loosening as the end-point, 12 hips (31.5%) needed acetabular revision but none needed femoral revision, demonstrating 100% survival (95% confidence interval 89 to 100). In young patients with high demands, the Furlong HAC-coated femoral component gives excellent long-term results.

p47phox and reactive oxygen species production modulate expression of microRNA-451 in macrophages

The production of microRNAs (miRNA) is influenced by various stimuli, including environmental stresses. We hypothesized that reactive oxygen species (ROS)-associated stress could regulate macrophage miRNA synthesis. miRNAs undergo unique steps of maturation processing through either one of two pathways of cytoplasmic processing. Unlike the canonical pathway, the regulation of alternative cytoplasmic processing of miRNA has not been fully elucidated yet. We cultured bone marrow derived macrophages (BMDM) from wild type (WT) and p47(phox-/-) mice and profiled miRNA expression using microarrays. We analyzed 375 miRNAs including four endogenous controls to normalize the data. At resting state, p47(phox-/-) BMDM has the markedly reduced expression of miR-451 compared to WT BMDM, without other significant differences. Unlike majority of miRNAs, miR-451 goes through the unique alternative processing pathway, in which Ago2 plays a key role. In spite of significant reduction of mature miR-451, however, its precursor form, pre-mir-451, was similar in both BMDMs, suggesting that the processing of pre-mir-451 is impaired in p47(phox-/-) BMDM. Moreover, p47(phox-/-) BMDM expressed significantly reduced level of Ago2. In contrast, Ago2 mRNA levels were similar in WT and p47(phox-/-) BMDM, suggesting a post-transcriptional defect of Ago2 production in p47(phox-/-) macrophages, which resulted in impaired processing of pre-miR-451. In order to examine the functional significance of miR-451 in macrophages, we cultured BMDMs from miR-451 knock-out mice. Of interest, miR-451-deficient BMDM exhibited reduced ROS generation upon zymosan stimulation, compared to WT BMDM. Our studies suggest functional crosstalk between ROS and miR-451 in the regulation of macrophage oxidant stress.

Growth kinetics of a diesel-degrading bacterial strain from petroleum-contaminated soil

A diesel-degrading bacterium was isolated from a diesel-contaminated site in Selangor, Malaysia. The isolate was tentatively identified as Acinetobacter sp. strain DRY12 based on partial 16S rDNA molecular phylogeny and Biolog GN microplate panels and Microlog database. Optimum growth occurred from 3 to 5% diesel and the strain was able to tolerate as high as 8% diesel. The optimal pH that supported growth of the bacterium was between pH 7.5 to 8.0. The isolate exhibited optimal growth in between 30 and 35 degrees C. The best nitrogen source was potassium nitrate (between 0.6 and 0.9% (w/v)) followed by ammonium chloride, sodium nitrite and ammonium sulphate in descending order. An almost complete removal of diesel components was seen from the reduction in hydrocarbon peaks observed using Solid Phase Microextraction Gas Chromatography analysis after 10 days of incubation. The best growth kinetic model to fit experimental data was the Haldane model of substrate inhibiting growth with a correlation coefficient value of 0.97. The maximum growth rate- micromax was 0.039 hr(-1) while the saturation constant or half velocity constant Ks and inhibition constant Ki, were 0.387% and 4.46%, respectively. MATH assays showed that 75% of the bacterium was found in the hexadecane phase indicating that the bacterium was hydrophobic. The characteristics of this bacterium make it useful for bioremediation works in the Tropics.

Effect of bacterial growth period on the sensitivity of the MTT assay for silver

Respiratory activity inhibition by toxic compounds in bacteria and yeast has been used to detect toxic compounds in the environment. Often the age of culture contributes towards the sensitivity of detection. In the present work, the effect of growth period on the sensitivity of an inhibitive assay for heavy metals using bacterial respiratory assay system based on the reduction of the water soluble tetrazolium dye MTT is reported. A silver-sensitive isolate was discovered to exhibit different sensitivities towards silver at different growth periods. An exponential decay model adequately described the inhibition due to silver. Analysis using ANOVA with post-hoc Tukey's test showed that the IC50 obtained by strain DRYS8 grown at the 12 hr- period in nutrient broth at 28 degrees C gave the lowest value compared to other growth periods. This study highlights the importance of taking into accounts growth conditions and age of culture in developing cellular-based bioassays.

Characterization of a sodium dodecyl sulphate-degrading Pseudomonas sp. strain DRY15 from Antarctic soil

A bacterium capable of biodegrading surfactant sodium dodecyl sulphate (SDS) was isolated from Antarctic soil. The isolate was tentatively identified as Pseudomonas sp. strain DRY15 based on carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. Growth characteristic studies showed that the bacterium grew optimally at 10 degrees C, 7.25 pH, 1 g l(-1) SDS as a sole carbon source and 2 g l(-1) ammonium sulphate as nitrogen source. Growth was completely inhibited at 5 g l(-1) SDS. At a tolerable initial concentration of 2 g l(-1), approximately 90% of SDS was degraded after an incubation period of eight days. The best growth kinetic model to fit experimental data was the Haldane model of substrate inhibition with a correlation coefficient value of 0.97. The maximum growth rate was 0.372 hr(-1) while the saturation constant or half velocity constant (Ks) and inhibition constant (Ki), were 0.094% and 11.212 % SDS, respectively. Other detergent tested as carbon sources at 1 g l(-1) was Tergitol NP9, Tergitol 15S9, Witconol 2301 (methyl oleate), sodium dodecylbenzene sulfonate (SDBS), benzethonium chloride, and benzalkonium chloride showed Tergitol NP9, Tergitol 15S9, Witconol 2301 and the anionic SDBS supported growth with the highest growth exhibited by SDBS.

Development of an inhibitive assay using commercial Electrophorus electricus acetylcholinesterase for heavy metal detection

Near-real-ime assay is anassay method that the whole process from sampling until results could be obtained in approximately Iess than one hour. The ElIman assay for acetyl cholinesterase (AChE) has near real-time potential due to its simplicity and fast assay time. The commercial acetylcholinesterase from Electrophorus electricus is well known for its uses in insecticides detection. A lesser known fact is AChE is also sensitive to heavy metals. A near real-time inhibitive assay for heavy metals using AChE from this source showed promising results. Several heavy metals such as copper, silver and mercury could be etected with IC50 values of1.212, 0.1185 and 0.097 mg I-1, respectively. The Limits of Detection (LOD) for copper, silver and mercury were 0.01, 0.015 and 0.01 mg I-1, respectively. TheLimits of quantitation (LOQ) or copper, silver and mercury were 0.196, 0.112 and 0.025 mg I-1, respectively. The LOQvalues for copper, silver and mercury were well below the maximum permissible limit for these metal ions as outlined by Malaysian Department of Environment. A polluted location demonstrated near real-time applicability of the assay with variation oftemporal levels of heavy metals detected. The results show that AChE from Electrophorus electricus has the potential to be used as a near real-time biomonitoring tool for heavy

Quality of life in Malaysian colorectal cancer patients: a preliminary result

OBJECTIVE

Rapidly increasing colorectal cancer (CRC) incidence in Malaysia and the introduction of cutting edge new treatments, which prolong survival, mean that treatment outcome measures meed to be evaluated, including consideration of patient's quality of life (QoL) assessment. There are limited data on QoL in CRC patients, especially in Malaysia. Therefore, this study was performed focusing on cancer stages and age groups.

METHODS

The cross sectional study was conducted from June to September 2011 at three public tertiary hospitals with the EORTC QLQ C-30 questionnaire in addition to face to face interview and review of medical records of 100 respondents.

RESULTS

The mean age was 57.3 (SD 11.9) years with 56.0% are males and 44.0% females, 62% of Malay ethnicity, 30% Chinese, 7% Indian and 1% Sikh. Majority were educated up to secondary level (42%) and 90% respondents had CRC stages III and IV. Mean global health status (GHS) score was 79.1 (SD 21.4). Mean scores for functional status (physical, emotional, role, cognitive, social) rangeds between 79.5 (SD 26.6) to 92.2 (SD 13.7). Mean symptom scores (fatigue, pain, nausea/vomiting, constipation, diarrhea, insomnia, dyspnoea, loss of appetite) ranged between 4.00 (SD 8.58) to 20.7 (SD 30.6). Respondents role function significantly deteriorates with increasing stage of the disease (p=0.044). Females had worse symptoms of pain (p=0.022), fatigue (p=0.031) and dyspnoea (p=0.031). Mean insomnia (p=0.006) and diarrhea (p=0.024) demonstrated significant differences between age groups.

CONCLUSION

QOL in CRC patients in this study was comparable to that in other studies done in developed countries. Pain, fatigue and dyspnoea are worse among female CRC patients. Given that functions deteriorates with advanced stage of the disease at diagnosis, a systematic screening programme to detect cases as early as possible is essential nationwide.

Isolation and characterization of an acrylamide-degrading yeast Rhodotorula sp. strain MBH23 KCTC 11960BP

As well as for chemical and environmental reasons, acrylamide is widely used in many industrial applications. Due to its carcinogenicity and toxicity, its discharge into the environment causes adverse effects on humans and ecology alike. In this study, a novel acrylamide-degrading yeast has been isolated. The isolate was identified as Rhodotorula sp. strain MBH23 using ITS rRNA analysis. The results showed that the best carbon source for growth was glucose at 1.0% (w/v). The optimum acrylamide concentration, being a nitrogen source for cellular growth, was at 500 mg l(-1). The highest tolerable concentration of acrylamide was 1500 mg l(-1) whereas growth was completely inhibited at 2000 mg l(-1). At 500 mg l(-1), the strain MBH completely degraded acrylamide on day 5. Acrylic acid as a metabolite was detected in the media. Strain MBH23 grew well between pH 6.0 and 8.0 and between 27 and 30 °C. Amides such as 2-chloroacetamide, methacrylamide, nicotinamide, acrylamide, acetamide, and propionamide supported growth. Toxic heavy metals such as mercury, chromium, and cadmium inhibited growth on acrylamide.

Factors influencing the surgical outcome of spontaneous intracerebral haematoma

The study was done for determination of the potential factors of good outcome in spontaneous intracerebral haematoma (SIH) which could be useful for selecting patients for surgical procedure. Subjects were 45 patients with spontaneous intracerebral haematoma (SIH)-Volume >20ml. They were admitted and surgically treated consecutively in Dhaka Medical College with in the 1st day to 4th day of ictus. Haematoma volume was measured on computed tomography (CT) at admission. Good outcome was measured by Glasgow Outcome Scale (GCS) score. Out of 45 patients with ICH, 18(40%) patients had basal ganglia haematoma, 13(28.88%) patients had lobar haematoma, and 2(4.45%) patients had cerebellar haematoma and 7(15.55%) patients had pure ventricular haematoma and 5(11.12%) patients ventricular extension from other location. Among these last 12 patients, 10(83.33%) patients died comparing only 7(21.21%) patients without ventricular involvement died. Fisher's exact test result shows p value is <0.001(Highly significant) and best outcome obtained in cases of lober haematoma in CT scan of brain, the mean volume was 46 cc. and there was strong association between the volume of haematoma and Glasgow outcome scale, that is, more the volume of blood, less the Glasgow Outcome Scale (GOS) and vice versa. P value was <0.001 (Highly significant). In another study the surgical outcome is best if it is done within 48 hours. Fisher's exact test result shows p value is <0.05. So, Good surgical outcome in spontaneous intracerebral haematoma (SICH) can be predicted on admission by volume of haematoma, location of haematoma, time lapse since ictus to surgery. These predictors may be helpful in selecting patients for surgical treatment.

Isolation and characterization of an acrylamide-degrading Antarctic bacterium

The presence of acrylamide in the environment poses a threat due to its well known neurotoxic, carcinogenic and teratogenic properties. Human activities in various geographical areas are the main anthropogenic source of acrylamide pollution. In this work, an acrylamide-degrading bacterium was isolated from Antarctic soil. The physiological characteristics and optimum growth conditions of the acrylamide-degrading bacteria were investigated. The isolate was tentatively identified as Pseudomonas sp. strain DRYJ7 based on carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. The results showed that the best carbon sources for growth was glucose and sucrose with no significant difference in terms of cellular growth between the two carbon sources (p>0.05). This was followed by fructose and maltose with fructose giving significantly higher cellular growth compared to maltose (p<0.05). Lactose and citric acid did not support growth. The optimum acrylamide concentration as a nitrogen source for cellular growth was at 500 mgl(-1). At this concentration, bacterial growth showed a 2-day lag phase before degradation took place concomitant with an increase in cellular growth. The isolate exhibited optimum growth in between pH 7.5 and 8.5. The effect of incubation temperature on the growth of this isolate showed an optimum growth at 15 degrees C. The characteristics of this isolate suggest that it would be useful in the bioremediation of acrylamide.

The development of an inhibitive determination method for zinc using a serine protease

A new inhibitive heavy metals determination method using trypsin has been developed. The enzyme was assayed using the casein-Coomassie-dye-binding method. In the absence of inhibitors, casein was hydrolysed to completion and the Coomassie-dye was unable to stain the protein and the solution became brown. In the presence of metals, the hydrolysis of casein was inhibited and the solution remained blue. The bioassay was able to detect zinc and mercury with IC50 (concentration causing 50% inhibition) values of 5.78 and 16.38 mg l(-1) respectively. The limits of detection (LOD), for zinc and mercury were 0.06 mg l(-1) (0.05-0.07, 95% confidence interval) and 1.06 mg l(-1) (1.017-1.102, 95% confidence interval), respectively. The limits of quantitation (LOQ) for zinc and mercury were 0.61 mg l(-1) (0.51-0.74 at a 95% confidence interval) and 1.35 mg l(-1) (1.29-1.40 at a 95% confidence interval), respectively. The IC50 value for zinc was much higher than the IC50 values for papain and Rainbow trout, but was within the range of Daphnia magna and Microtox. The IC50 value for zinc was only lower than those for immobilized urease. Other toxic heavy metals, such as lead, silver arsenic, copper and cadmium, did not inhibit the enzyme at 20 mg l(-1). Using this assay we managed to detect elevated zinc concentrations in several environmental samples. Pesticides, such as carbaryl, flucythrinate, metolachlor glyphosate, diuron, diazinon, endosulfan sulphate, atrazine, coumaphos, imidacloprid, dicamba and paraquat, showed no effect on the activity of trypsin relative to control (One-way ANOVA, F(12,26)= 0.3527, p> 0.05). Of the 17 xenobiotics tested, only (sodium dodecyl sulphate) SDS gave positive interference with 150% activity higher than that of the control at 0.25% (v/v).

Isolation and characterization of an acrylamide-degrading Bacillus cereus

Several local acrylamide-degrading bacteria have been isolated. One of the isolate that exhibited the highest growth on acrylamide as a nitrogen source was then further characterized. The isolate was tentatively identified as Bacillus cereus strain DRY135 based on carbon utilization profiles using Biolog GP plates and partial 16S rDNA molecular phylogeny. The isolate grew optimally in between the temperatures of 25 and 30 degrees C and within the pH range of 6.8 to 7.0. Glucose, fructose, lactose, maltose, mannitol, citric acid and sucrose supported growth with glucose being the best carbon source. Different concentrations of acrylamide ranging from 100 to 4000 mg l(-1) incorporated into the growth media shows that the highest growth was obtained at acrylamide concentrations of between 500 to 1500 mg l(-1). At 1000 mg l(-1) of acrylamide, degradation was 90% completed after ten days of incubation with concomitant cell growth. The metabolite acrylic acid was detected in the media during degradation. Other amides such as methacrylamide, nicotinamide, acetamide, propionamide and urea supported growth with the highest growth supported by acetamide, propionamide and urea. Strain DRY135, however was not able to assimilate 2-chloroacetamide. The characteristics of this isolate suggest that it would be useful in the bioremediation of acrylamide.

Characterization of a diesel-degrading strain isolated from a hydrocarbon-contaminated site

A diesel-degrading bacterium has been isolated from a diesel-polluted site. The isolate was tentatively identified as Staphylococcus aureus strain DRY11 based on partial 16S rDNA molecular phylogeny and Biolog GP microplate panels and Microlog database. Isolate 11 showed an almost linear increase in cellular growth with respect to diesel concentrations with optimum growth occurring at 4% (v/v) diesel concentration. Optimization studies using different nitrogen sources showed that the best nitrogen source was potassium nitrite. Sodium nitrite was optimum at 1.2 g l(-1) and higher concentrations were strongly inhibitory to cellular growth. The optimal pH that supported growth of the bacterium was between 7.5 to 8.0 and the isolate exhibited optimal broad temperature supporting growth on diesel from 27 to 37 degrees C. An almost complete removal of diesel components was seen from the reduction in hydrocarbon peaks observed using Solid Phase Microextraction Gas Chromatography analysis after 5 days of incubation. The characteristics of this bacterium suggest that it is suitable for bioremediation of diesel spills and pollutions in the tropics.

Development of an inhibitive enzyme assay for copper

In this work the development of an inhibitive assay for copper using the molybdenum-reducing enzyme assay is presented. The enzyme is assayed using 12-molybdophosphoric acid at pH 5.0 as an electron acceptor substrate and NADH as the electron donor substrate. The enzyme converts the yellowish solution into a deep blue solution. The assay is based on the ability of copper to inhibit the molybdenum-reducing enzyme from the molybdate-reducing Serratia sp. Strain DRY5. Other heavy metals tested did not inhibit the enzyme at 10 mg l(-1). The best model with high regression coefficient to measure copper inhibition is one-phase binding. The calculated IC50 (concentration causing 50% inhibition) is 0.099 mg l(-1) and the regression coefficient is 0.98. The comparative LC50, EC50 and IC50 data for copper in different toxicity tests show that the IC50 value for copper in this study is lower than those for immobilized urease, bromelain, Rainbow trout, R. meliloti, Baker's Yeast dehydrogenase activity Spirillum volutans, P. fluorescens, Aeromonas hydrophilia and synthetic activated sludge assays. However the IC50 value is higher than those for Ulva pertusa and papain assays, but within the reported range for Daphnia magna and Microtox assays.

Isolation and characterization of an SDS-degrading Klebsiella oxytoca

Sodium dodecyl sulfate (SDS) is one of the main components in the detergent and cosmetic industries. Its bioremediation by suitable microorganism has begun to receive greater attention as the amount of SDS usage increases to a point where treatment plants would not be able to cope with the increasing amount of SDS in wastewater. The purpose of this work was to isolate local SDS-degrading bacteria. Screening was carried out by the conventional enrichment-culture technique. Six SDS-degrading bacteria were isolated. Of these isolates, isolate S14 showed the highest degradation of SDS with 90% degradation after three days of incubation. Isolate S14 was tentatively identified as Klebsiella oxytoca strain DRY14 based on carbon utilization profiles using Biolog GN plates and partial 16S rDNA molecular phylogeny. SDS degradation by the bacterium was optimum at 37 degrees 0. Ammonium sulphate; at 2.0 g l(-1), was found to be the best nitrogen source for the growth of strain DRY14. Maximum growth on SDS was observed at pH 7.25. The strain exhibited optimum growth at SDS concentration of 2.0 g l(-1) and was completely inhibited at 10 g l(-1) SDS. At the tolerable initial concentration of 2.0 g l(-1), almost 80% of 2.0 g l(-1) SDS was degraded after 4 days of incubation concomitant with increase in cellular growth. The K(m(app) and V(max(app)) values calculated for the alkylsulfatase from this bacterium were 0.1 mM SDS and 1.07 micromol min(-1) mg(-1) protein, respectively.

Reduction of Mo(VI) by the bacterium Serratia sp. strain DRY5

The need to isolate efficient heavy metal reducers for cost effective bioremediation strategy have resulted in the isolation of a potent molybdenum-reducing bacterium. The isolate was tentatively identified as Serratia sp. strain DRY5 based on the Biolog GN carbon utilization profiles and partial 16S rDNA molecular phylogeny. Strain DRY5 produced 2.3 times the amount of Mo-blue than S. marcescens strain Dr.Y6, 23 times more than E. coli K12 and 7 times more than E. cloacae strain 48. Strain DRY5 required 37 degrees C and pH 7.0 for optimum molybdenum reduction. Carbon sources such as sucrose, maltose, glucose and glycerol, supported cellular growth and molybdate reduction after 24 hr of static incubation. The most optimum carbon source that supported reduction was sucrose at 1.0% (w/v). Ammonium sulphate, ammonium chloride, glutamic acid, cysteine, and valine supported growth and molybdate reduction with ammonium sulphate as the optimum nitrogen source at 0. 2% (w/v). Molybdate reduction was optimally supported by 30 mM molybdate. The optimum concentration of phosphate for molybdate reduction was 5 mM when molybdate concentration was fixed at 30 mM and molybdate reduction was totally inhibited at 100 mM phosphate. Mo-blue produced by this strain shows a unique characteristic absorption profile with a maximum peak at 865 nm and a shoulder at 700 nm, Dialysis tubing experiment showed that 95.42% of Mo-blue was found in the dialysis tubing suggesting that the molybdate reduction seen in this bacterium was catalyzed by enzyme(s). The characteristics of isolate DRY5 suggest that it would be useful in the bioremediation ofmolybdenum-containing waste.

Assessment of Clarias batrachus as a source of acetylcholinesterase (AchE) for the detection of insecticides

An inhibitive assay of insecticides using Acetylcholinesterase (AChE) from the local fish Clarias batrachus is reported. AChE was assayed according to the modified method of Ellman. Screening of insecticide and heavy metals showed that carbofuran and carbaryl strongly inhibited C. batrachus AChE. The inhibition concentration (IC) IC50 values (and the 95% confidence interval) for both carbofuran and carbaryl inhibition on C. batrachus AChE at 6.66 (5.97-7.52) and 130.00 (119.3-142.5) microg l(-1), respectively was within the IC50 range of Electrophorus electricus at 6.20 (6.03-6.39) and 133.01 (122.40-145.50) microg l(-1), respectively and were much lower than bovine AChE at 20.94 (19.53-22.58) and 418.80 (390.60-451.60) microg l(-1), respectively. The results showed that C. batrachus have the potential to be used as a cheaper and more readily available source of AChE than other more commercially available sources.

A simple method to screen for azo-dye-degrading bacteria

A stab-culture method was adapted to screen for azo dyes-decolorizing bacteria from soil and water samples. Decolorized azo dye in the lower portion of the solid media indicates the presence of anaerobic azo dyes-decolorizing bacteria, while aerobic decolorizing bacteria decolorizes the surface portion of the solid media. Of twenty soil samples tested, one soil sample shows positive results for the decolourisation of two azo dyes; Biebrich scarlet (BS) and Direct blue 71 (DB) under anaerobic conditions. A gram negative and oxidase negative bacterial isolate was found to be the principal azo dyes degrader The isolate was identified by using the Biolog identification system as Serratia marcescens.

Isolation and characterization of a Pseudomonas diesel-degrading strain from Antarctica

A diesel-degrading bacterium from Antarctica has been isolated. The isolate was tentatively identified as Pseudomonas sp. strain DRYJ3 based on partial 16S rDNA molecular phylogeny and Biolog GN microplate panels and Microlog database. Growth on diesel was supported optimally by ammonium sulphate, nitrate and nitrite. The bacterium grew optimally in between 10 and 15 degrees C, pH 7.0 and 3.5% (v/v) diesel. The biodegradation of diesel oil by the strain increased in efficiency from the second to the sixth day of incubation from 1.4 to 18.8% before levelling off on the eighth day n-alkane oxidizing and aldehyde reductase activities were detected in the crude enzyme preparation suggesting the existence of terminal n-alkane oxidizing activity in this bacterium.

An improved enzyme assay for molybdenum-reducing activity in bacteria

Molybdenum-reducing activity in the heterotrophic bacteria is a phenomenon that has been reported for more than 100 years. In the presence of molybdenum in the growth media, bacterial colonies turn to blue. The enzyme(s) responsible for the reduction of molybdenum to molybdenum blue in these bacteria has never been purified. In our quest to purify the molybdenum-reducing enzyme, we have devised a better substrate for the enzyme activity using laboratory-prepared phosphomolybdate instead of the commercial 12-phosphomolybdate we developed previously. Using laboratory-prepared phosphomolybdate, the highest activity is given by 10:4-phosphomolybdate. The apparent Michaelis constant, Km for the laboratory-prepared 10:4-phosphomolybdate is 2.56 +/- 0.25 mM (arbitrary concentration), whereas the apparent V(max) is 99.4 +/- 2.85 nmol Mo-blue min(-1) mg(-1) protein. The apparent Michaelis constant or Km for NADH as the electron donor is 1.38 +/- 0.09 mM, whereas the apparent V(max) is 102.6 +/- 1.73 nmol Mo-blue min(-1) mg(-l) protein. The apparent Km and V(max) for another electron donor, NADPH, is 1.43 +/- 0.10 mM and 57.16 +/- 1.01 nmol Mo-blue min(-1) mg(-1) protein, respectively, using the same batch of molybdenum-reducing enzyme. The apparent V(max) obtained for NADH and 10:4-phosphomolybdate is approximately 13 times better than 12-phoshomolybdate using the same batch of enzyme, and hence, the laboratory-prepared phosphomolybdate is a much better substrate than 12-phoshomolybdate. In addition, 10:4-phosphomolybdate can be routinely prepared from phosphate and molybdate, two common chemicals in the laboratory.

Regenerating nodules in arteriohepatic syndrome: a case report

We report the multimodality imaging features of two cases of arteriohepatic syndrome (AS) complicated by a regenerating nodule. CT, ultrasound and MRI revealed nodular liver lesions with cirrhotic and portal hypertension changes. A large mass identified in both cases appeared hyperdense on unenhanced CT, hypointense on T(2) weighted imaging and showed normal-appearing hepatic vasculature coursing through the lesion in all contrast-enhanced imaging, highly suggestive of a regenerating nodule. Knowledge of this entity is quite important as patients with AS are also predisposed to hepatocellular carcinoma.

Hexavalent molybdenum reduction to molybdenum blue by S. marcescens strain Dr. Y6

A molybdate-reducing bacterium has been locally isolated. The bacterium reduces molybdate or Mo(6+) to molybdenum blue (molybdate oxidation states of between 5+ and 6+). Different carbon sources such as acetate, formate, glycerol, citric acid, lactose, fructose, glucose, mannitol, tartarate, maltose, sucrose, and starch were used at an initial concentration of 0.2% (w/v) in low phosphate media to study their effect on the molybdate reduction efficiency of bacterium. All of the carbon sources supported cellular growth, but only sucrose, maltose, glucose, and glycerol (in decreasing order) supported molybdate reduction after 24 h of incubation. Optimum concentration of sucrose for molybdate reduction is 1.0% (w/v) after 24 h of static incubation. Ammonium sulfate, ammonium chloride, valine, OH-proline, glutamic acid, and alanine (in the order of decreasing efficiency) supported molybdate reduction with ammonium sulfate giving the highest amount of molybdenum blue after 24 h of incubation at 0.3% (w/v). The optimum molybdate concentration that supports molybdate reduction is between 15 and 25 mM. Molybdate reduction is optimum at 35 degrees C. Phosphate at concentrations higher than 5 mM strongly inhibits molybdate reduction. The molybdenum blue produced from cellular reduction exhibits a unique absorption spectrum with a maximum peak at 865 nm and a shoulder at 700 nm. The isolate was tentatively identified as Serratia marcescens Strain Dr.Y6 based on carbon utilization profiles using Biolog GN plates and partial 16s rDNA molecular phylogeny.

Is type 2 diabetes a chronic inflammatory/autoimmune disease?

The classification of diabetes mellitus into 2 main types, defined as Type 1 and 2 diabetes (T1DM, T2DM) relies mostly on the requirement of insulin therapy and on the presence of detectable immunologic abnormalities. However, this distinction is far from straightforward and there is considerable overlap between these 2 types of diabetes. Islet cell autoimmunity, which is characteristic of T1DM, appears in fact to be present in up to 10-15% of subjects diagnosed clinically with T2DM. In the UK Prospective Diabetes Study (UKPDS), it was reported that in patients diagnosed with in T2DM, the presence of autoantibodies to the enzyme glutamic acid decarboxylase (GAD) and cytoplasmic islet cell antibodies (ICA) were a predictor of insulin requirement as compared with patients not carrying these autoantibodies. These results are strikingly similar to a number of prospective studies carried out in childhood diabetes. If islet cell autoimmunity is truly present in 10-15% of subjects clinically diagnosed with T2DM, up to two million Americans might have an unidentified autoimmune form of T2DM, a prevalence similar to that of recent onset childhood diabetes. In addition, we found that in a subset of T2DM patients, a pronounced activation of the acute phase response that seems to be associated with islet cell autoimmunity. These results may in part explain the defect in insulin secretion as well as insulin resistance seen in T2DM. The identification of a subgroup of individuals at risk of developing T2DM using autoantibody as well as inflammatory markers is of public health interest, not only for the correct classification of diabetes, but also because immunomodulatory therapeutic strategies could potentially be instituted sufficiently early in a large number of patients diagnosed as having T2DM and most likely delay the onset of insulin requirement and the complications related with hyperglycemia.

Transient paraplegia as a presenting feature of aortic dissection in a young man

This report describes a case of aortic dissection in a 32 year old man who presented with mild central chest pain and transient paraplegia. Complete recovery of paraplegia in aortic dissection has previously been reported but this is the first case report in which full resolution of the paraplegia occurred within half an hour of presentation. The case emphasises the importance of careful history taking and eliciting subtle clinical signs, which helped in arriving at the correct diagnosis in this unusual presentation.

Spontaneous supraglottic haemorrhage in a patient receiving warfarin sodium treatment

A case of spontaneous, isolated supraglottic haemorrhage in a patient recently started with warfarin sodium treatment is described. The symptoms of sore throat, dysphonia, stridor, dysphagia or a neck swelling in a patient taking anticoagulants should alert the clinician to the possibility of this rare but potentially fatal complication.

Actinomycosis of the post-cricoid space: an unusual cause of dysphagia

Cervicofacial actinomycosis is known to affect many soft tissues and bony structures in the head and neck. However to the authors' knowledge, actinomycosis of the post-cricoid region has not been previously reported. A case of a 74-year-old male who developed actinomycosis of the post-cricoid region after radiotherapy for a laryngeal carcinoma is presented. Actinomycosis should be considered in the differential diagnosis of dysphagia following radiotherapy for squamous cell carcinoma of the larynx, as early treatment is likely to result in a favourable outcome.

Parathyroid hormone-related protein-(1--36) stimulates renal tubular calcium reabsorption in normal human volunteers: implications for the pathogenesis of humoral hypercalcemia of malignancy

All would agree that hypercalcemia occurs among patients with humoral hypercalcemia of malignancy (HHM) as a result of osteoclastic bone resorption. Some studies suggest that enhanced renal calcium reabsorption, which plays an important pathophysiological role in the hypercalcemia occurring in primary hyperparathyroidism, is also important pathophysiologically in HHM. Other studies have not agreed. In large part, these differences result from the inability to accurately assess creatinine and calcium clearance in critically ill subjects with HHM. To circumvent these issues, we have developed steady state 48-h PTH-related protein (PTHrP) infusion and 8-h hypercalcemic calcium clamp protocols. These techniques allow assessment of the effects of steady state PTHrP and calcium infusions in normal healthy volunteers in a setting in which renal function is stable and measurable and in which the filtered load of calcium can be matched in PTHrP- and calcium-infused subjects. Normal subjects were infused with saline (placebo), PTHrP, or calcium. Subjects receiving PTHrP, as expected, displayed mild hypercalcemia (10.2 mg/dL), suppression of endogenous PTH-(1--84), and phosphaturia. Subjects receiving the hypercalcemic calcium clamp displayed indistinguishable degrees of hypercalcemia and PTH suppression. Despite their matched degrees of hypercalcemia and PTH suppression, the two groups differed importantly with regard to fractional calcium excretion (FECa). The hypercalcemic calcium clamp group was markedly hypercalciuric (FECa averaged 6.5%), whereas FECa in the PTHrP-infused subjects was approximately 50% lower (between 2.5--3.7%), and no different from that in the normal controls, which ranged from 1.5--3.0%. These studies demonstrate that PTHrP is able to stimulate renal calcium reabsorption in healthy volunteers. These studies suggest that PTHrP-induced renal calcium reabsorption, in concert with the well established acceleration of osteoclastic bone resorption, contributes in a significant way to the hypercalcemia observed in patients with HHM.

Hepatocyte growth factor overexpression in the islet of transgenic mice increases beta cell proliferation, enhances islet mass, and induces mild hypoglycemia

Hepatocyte growth factor (HGF) is produced in pancreatic mesenchyme-derived cells and in islet cells. In vitro, HGF increases the insulin content and proliferation of islets. To study the role of HGF in the islet in vivo, we have developed three lines of transgenic mice overexpressing mHGF using the rat insulin II promoter (RIP). Each RIP-HGF transgenic line displays clear expression of HGF mRNA and protein in the islet. RIP-mHGF mice are relatively hypoglycemic in post-prandial and fasting states compared with their normal littermates. They display inappropriate insulin production, striking overexpression of insulin mRNA in the islet, and a 2-fold increase in the insulin content in islet extracts. Importantly, beta cell replication rates in vivo are two to three times higher in RIP-HGF mice. This increase in proliferation results in a 2-3-fold increase in islet mass. Moreover, the islet number per pancreatic area was also increased by approximately 50%. Finally, RIP-mHGF mice show a dramatically attenuated response to the diabetogenic effects of streptozotocin. We conclude that the overexpression of HGF in the islet increases beta cell proliferation, islet number, beta cell mass, and total insulin production in vivo. These combined effects result in mild hypoglycemia and resistance to the diabetogenic effects of streptozotocin.

The effect of thyroid hormone on size of fat depots accounts for most of the changes in leptin mRNA and serum levels in the rat

The physiological consequences and mechanism(s) for thyroid hormone-induced alterations in serum leptin are not known. To address this, leptin expression in rats was evaluated in relationship to food intake, fat mass, and body temperature in rats with pharmacologically altered thyroid status. Total body weight, food intake, and temperature were decreased in hypothyroid rats. Fat weight was decreased in both chronically hypothyroid and hyperthyroid rats (n = 6/group). Serum leptin was linearly correlated with fat weight, epididymal and retroperitoneal fat leptin mRNA concentration, but not total body weight. Serum leptin was decreased in the chronically hyperthyroid rats. When fat weight was used as a covariant, serum leptin was not different between the three groups. Epididymal fat leptin mRNA was higher in euthyroid (n = 7) than in hypothyroid and hyperthyroid rats. Retroperitoneal fat leptin mRNA was not affected by thyroid status. A positive linear relationship between food intake and free triiodothyronine (FT3) index was observed, but not between food intake and serum leptin alone. In a time course study, serum leptin, epididymal fat leptin mRNA content, and fat weight did not change within 24 hours of high-dose triiodothyronine (T3) (n = 6/group), but both temperature and epididymal fat S14 mRNA content rapidly increased. These findings demonstrate that thyroid state influences circulating leptin levels, but primarily does so indirectly through the regulation of fat mass. Leptin does not influence core body temperature across thyroidal state. Finally, thyroid state is more important to regulate food intake, through an as yet undefined mechanism, than are thyroid state-associated changes in serum leptin.

Usefulness of exercise echocardiography in predicting cardiac events in an outpatient population

The prognostic value of exercise echocardiography in an outpatient population is not well defined. A total of 1,020 consecutive patients referred for exercise echocardiography in an ambulatory care setting were studied by reviewing their medical records and exercise echocardiographic data. Of these, 71 (7%) were excluded due to technically inadequate tests, leaving 949 patients who were included in the analysis. A positive exercise echocardiogram (EE) was defined as an appearance of a new wall motion abnormality or worsening of a baseline abnormality. Cardiac events, defined as myocardial infarction, coronary angioplasty, coronary bypass surgery, and death, were documented during a 12-month follow-up period. Cardiac events occurred in 17% of patients (26 of 152) with a positive exercise echocardiogram (EE) and in 2.5% (20 of 797) with a negative EE (p <0.001). The incidence of myocardial infarction (2.6% vs 0.4%, p <0.02), coronary angioplasty (7% vs 1%, p <0.001), and coronary bypass surgery (9% vs 1%, p <0.001) were higher in patients with a positive versus a negative EE. There was 1 death in the positive study group and none in the negative group. Significant independent variables (p <0.05) that predicted cardiac events included a positive exercise electrocardiogram, history of coronary angioplasty, nonspecific ST-T changes on the baseline electrocardiogram, double product <25,000, men, chest pain on exercise test, and a positive exercise electrocardiogram. On a stepwise logistic regression model, exercise echocardiography emerged as an independent predictor of future cardiac events in an outpatient population. This predictive value was enhanced in the presence of a positive exercise electrocardiogram compared with a negative exercise electrocardiogram (24.2% vs 7.9%, p <0.03). Our study suggests that exercise echocardiography is an independent predictor of future cardiac events in an outpatient population.

Localization of NADPH-diaphorase reactivity in the chick and mouse thyroid gland

In the present study, nicotinamide adenine dinucleotide hydrogen phosphate-diaphorase (NADPH-d) histochemistry has been used as a marker for nitric oxide synthase (NOS). The colored reaction product, formazan, was localized in neuronal cell bodies, nerve fibers, and vascular endothelium in the thyroid of chick and mouse. In these two animal species, most of the NADPH-d-labeled neuronal cell bodies were found in the thyroid capsule and interfollicular connective tissue while some were associated with blood vessels. Most nerve fibers travelled with blood vessels supplying the thyroid gland, while a few of them were intimately associated with the thyroid follicular cells. Control sections not incubated with beta-NADPH failed to show labeling of the above structures. It is concluded that nitric oxide may play an important role in endocrine secretion by controlling the regional blood flow in the thyroid gland and by directly acting on the thyroid follicular cells.