Decay of Thermal Tolerance in Queensland Fruit Fly Eggs (Bactrocera tryoni, Diptera: Tephritidae) Following Non-Lethal Heat Hardening

Quarantine disinfestation treatments for Queensland fruit fly (Bactrocera tryoni (Froggatt)) have been developed which use high temperatures to kill preimaginal life stages within fruit prior to export. However, thermal tolerance of individuals can be increased if they are exposed to elevated temperatures before disinfestation treatment. The rate that this thermal conditioning decays after exposure, and the effect of temperature on this decay process, were investigated. Eggs of B. tryoni were exposed to a nonlethal hot water treatment at 38°C for 15 min, 1 or 3 h, then held in air at 25°C for times ranging from 15 min to 12 h, before being exposed to hot water disinfestation at 46°C for various times. From each of these cohorts, the lethal time for 99% mortality (LT99) was calculated. The LT99 of B. tryoni eggs increased with longer conditioning times at 38°C. For each conditioning time, the LT99 decreased with longer delay periods at 25°C prior to disinfestation. The rate of decrease was greatest during the first hour of delay, after which the rate of decrease slowed and tended toward zero. This induction and decay was modeled using a double-exponential equation. These experiments show that thermal conditions prior to disinfestation, and the time delay before the procedure commences, both influence the response of the insect to the disinfestation treatment. These results have implications for the specification of postharvest quarantine treatments, which are usually expressed only in terms of a fruit-center target temperature.

Pediatric intestinal transplant listing criteria - a call for a change in the new era of intestinal failure outcomes

Current listing indications used for intestinal transplantation (IT) were proposed in 2001. We undertook the present single center study to see if these criteria are still valid. The 2001 criteria (advanced cholestasis, loss of >50% central venous catheter (CVC) sites, ≥2 sepsis/year, ultrashort bowel) were compared in children with intestinal failure in old era-1998-2005 (N = 99) to current era-2006-2012 (N = 91) to predict the need for IT using sensitivity, specificity, NPV and PPV. Two 2001 criteria had poorer predictive value in the current era: Advanced cholestasis (PPV 64% old vs. 40% current era; sensitivity 84% vs. 65%, respectively) and ultrashort bowel (PPV 100% old vs. 9% current era; sensitivity 10% vs. 4%, respectively). Three newly proposed criteria had high predictive value: ≥2 ICU admissions (p = 0.0001, OR 23.6, 95% CI 2.7-209.8), persistent bilirubin >75 mmol/L despite lipid strategies (p = 0.0005, OR 24.0, 95% CI 3.2-177.4), and loss of ≥3 CVC sites (p = 0.0003, OR 33.3, 95% CI 18.8-54.0). There was 98% probability of needing IT when two of these new criteria were present. The 2001 IT criteria have limited predictive ability in the current era and should be revised. A multicenter study is required to validate the findings of this single center experience.

Admission to medical schools in Sri Lanka: predictive validity of selection criteria

OBJECTIVE

To assess the extent to which current selection criteria predict success in Sri Lanka's medical schools.

METHODS

The study sample consisted of all students selected to all six medical schools in two consecutive entry cohorts. The aggregate marks of these students at the General Certificate of Education (GCE) Advanced Level examination, the district of entry, admission category, candidate type (school/private) and gender, were identified as entry point variables. Success in medical school was measured in four ways: the ability to pass the first summative examination and the final examination at the first attempt, and obtaining honours in either examination. Multivariate analysis using logistic regression was used to assess the extent to which these entry point factors predict variability in outcome measures.

RESULTS

Aggregate scores among the 1740 students in the study sample ranged from 212 to 356, with a median of 285. The male:female ratio was 1.4:1. Private candidates (taking the examination for the third time) accounted for 22% of students. Being a school candidate, female and having a higher aggregate score, were the only independent predictors of success for all four outcome measures. The aggregate score alone accounted for only 1-7% of the variation in performance in medical school.

CONCLUSIONS

Marks obtained at the A Level examination (the only academic criterion currently used for selection of medical students in Sri Lanka) is a poor predictor of success in medical school.

[Coronary revascularization with extracorporeal circulation, aortic clamping or OPCAB: does the method's choice influence the results?]

BACKGROUND AND OBJECTIVES

Off pump CABG-OPCAB is the most recent development in coronary surgery and is aimed to avoid the complications of extracorporeal circulation and to compete with interventional cardiology. The objective of this study is to compare 3 methods for cardiac support for CABG.

METHODS

Between February 2001 and December 2002 ninety consecutive patients were operated by the same surgeon and the same team with the following techniques: extracorporeal circulation (CEC) and ischaemic arrest, CEC and beating heart, and OPCAB.

RESULTS

There were no difference in mortality and morbidity for the 3 groups of patients. The OPCAB group showed less ventilation time, less blood transfusion needs and shorter hospital stays than the other 2 groups of patients that showed no differences between each other.

CONCLUSION

OPCAB is safe and showed slight advantage over CEC supported groups but the number of grafts per patient was smaller.

A fluorescence energy transfer method for analyzing protein oligomeric structure: application to phospholamban

We have developed a method using fluorescence energy transfer (FET) to analyze protein oligomeric structure. Two populations of a protein are labeled with fluorescent donor and acceptor, respectively, then mixed at a defined donor/acceptor ratio. A theoretical simulation, assuming random mixing and association among protein subunits in a ring-shaped homo-oligomer, was used to determine the dependence of FET on the number of subunits, the distance between labeled sites on different subunits, and the fraction of subunits remaining monomeric. By measuring FET as a function of the donor/acceptor ratio, the above parameters of the oligomeric structure can be resolved over a substantial range of their values. We used this approach to investigate the oligomeric structure of phospholamban (PLB), a 52-amino acid protein in cardiac sarcoplasmic reticulum (SR). Phosphorylation of PLB regulates the SR Ca-ATPase. Because PLB exists primarily as a homopentamer on sodium dodecyl sulfate polyacrylamide gel electrophoresis, it has been proposed that the pentameric structure of PLB is important for its regulatory function. However, this hypothesis must be tested by determining directly the oligomeric structure of PLB in the lipid membrane. To accomplish this goal, PLB was labeled at Lys-3 in the cytoplasmic domain, with two different amine-reactive donor/acceptor pairs, which gave very similar FET results. In detergent solutions, FET was not observed unless the sample was first boiled to facilitate subunit mixing. In lipid bilayers, FET was observed at 25 degrees C without boiling, indicating a dynamic equilibrium among PLB subunits in the membrane. Analysis of the FET data indicated that the dye-labeled PLB is predominantly in oligomers having at least 8 subunits, that 7-23% of the PLB subunits are monomeric, and that the distance between dyes on adjacent PLB subunits is about 10 A. A point mutation of PLB (L37A) that runs as monomer on SDS-PAGE showed no energy transfer, confirming its monomeric state in the membrane. We conclude that FET is a powerful approach for analyzing the oligomeric structure of PLB, and this method is applicable to other oligomeric proteins.

One-day general practice morbidity survey in Sri Lanka

BACKGROUND

National morbidity surveys provide valuable data for monitoring the health needs of populations, health policy planning and design of medical curricula. In order to meet a long-standing need for such information in Sri Lanka, a nationwide general practice morbidity survey was conducted for the first time in 1996.

OBJECTIVES

We aimed to identify people's needs by determining the reasons for encounter or the demand for care with GPs/family physicians, to illustrate the pattern of morbidity in general practice and to determine the average daily workload of GPs in Sri Lanka.

METHOD

A random sample of 75 GPs were requested to complete a Practitioner Profile Questionnaire (PPQ) and to record on an encounter form (EF) the reason/s for encounter (RFE) and problems managed during all consultations on 4 July. Central coding of the RFEs and problems defined was done using the International Classification of Primary Care (ICPC).

RESULTS

Forty GPs (53.3%) completed the PPQ, while the EF received a response from 34 (43.3%). The GP profile showed a male to female ratio of 7:1, none below 35 years and none qualified after 1984. The average daily workload was 74. It was estimated that GPs handle at least 26.5% of the primary care morbidity. Children accounted for 32% of consultations. There was a significantly higher proportion of children (P < 0.0001) and of the elderly (P < 0.05) in the consulting population compared with the general population. In 2068 encounters, 3448 RFEs and 2087 problems had been recorded. Respiratory and General chapters included 55% of the RFEs. By ICPC rubrics, 27 of the top thirty RFEs were for common symptoms. In addition to acute illnesses, asthma, hypertension and diabetes as well as preventive care activities were within the top 12 problems managed.

CONCLUSIONS

The fact that many common illnesses, chronic diseases and preventive treatments are dealt with in general practice shows the necessity to include family medicine in the undergraduate curriculum of all medical schools. Undergraduate and postgraduate training in family medicine should concentrate more on child care and care of the elderly. Suitable incentives may be necessary to motivate younger doctors to become GPs to meet the medical care needs of the community.

Anthelmintics. A comparative review of their clinical pharmacology

Virtually all the important helminth infections in humans can be treated with one of 5 anthelmintics currently in use: albendazole, mebendazole, diethylcarbamazine, ivermectin and praziquantel. These drugs are vital not only for the treatment of individual infections, but also useful in controlling transmission of the more common infections. This article reviews briefly the pharmacology of these 5 drugs, and then discusses current issues in the use of anthelmintics in the treatment and/or control of soil-transmitted nematode infections, filariasis, onchocerciasis, schistosomiasis (and other trematode infections), neurocysticercosis and hydatidosis. Mebendazole and albendazole are most effective against intestinal nematodes, but are contraindicated during the first trimester of pregnancy. The efficacy of prolonged therapy with these 2 drugs for treatment of larval cestode infections has not yet been established. Diethylcarbamazine is widely used to treat and control lymphatic filariasis, but adverse effects related to death of microfilariae or damage to adult worms may be marked. While ivermectin has been used in the treatment of patients with onchocerciasis, it is also undergoing investigation against lymphatic filariae. Praziquantel, used to treat schistosome infections, is also effective in other trematode infections and adult cestode infections.

Comparison of minimum inhibitory concentrations to methicillin in heterogeneous and homogeneous methicillin resistant Staphylococcus aureus

OBJECTIVE

To determine the minimum inhibitory concentration (MIC) to methicillin and compare it with the type of methicillin resistance in methicillin resistant Staphylococcus aureus (MRSA) isolated from clinical samples, and to evaluate the usefulness of beta-lactamase resistant penicillins such as cloxacillin for treatment of minor MRSA infections.

DESIGN

Sixty-five strains of MRSA isolated from clinical samples were studied. Homogeneous and heterogeneous resistance to methicillin of these strains was determined by an efficiency of plating technique. The MICs to methicillin of all homogeneously resistant strains and an equal number of heterogeneously resistant strains were determined by the 'E' test.

SETTING

General Hospital, Colombo; De Soysa Maternity Hospital for Women; Lady Ridgeway Hospital for Children.

RESULTS

171 strains of S aureus were isolated from specimens processed in the laboratory of the Department of Microbiology, Faculty of Medicine Colombo, during a 14-month period. Seventy (40.9%) were methicillin resistant. Fifty-three MRSA strains (81.5%) were heterogeneously resistant to methicillin. Only 12 of 65 strains were homogeneously resistant. Nine of 12 of the homogeneously resistant strains were from surgical wards. MICs for methicillin in the two groups were compared. Six of 12 (50%) homogeneously resistant strains had very high levels of resistance to methicillin (MIC > 200 micrograms/ml). In contrast the MICs of all the heterogeneously resistant strains ranged from 16 micrograms/ml to 96 micrograms/ml.

CONCLUSIONS

The majority of clinical isolates of MRSA from hospitals in Colombo, Sri Lanka were heterogeneously resistant to methicillin with lower MICs for methicillin than the homogeneously resistant strains. Thus, beta-lactamase resistance penicillins such as cloxacillin may have a place in the treatment of minor MRSA infections. Surveillance studies to determine if there is an increase of homogeneously methicillin resistant MRSA are required.

Tryptophan dynamics of the FK506 binding protein: time-resolved fluorescence and simulations

The FK506-binding protein (FKBP12) is important in the immunosuppressant action of FK506 and rapamycin. We have investigated Trp side chain dynamics in FKBP12, with and without a bound immunosuppressant, by measuring the Trp time-resolved fluorescence anisotropy decay r(t). The r(t) for W59 in aqueous uncomplexed FKBP12 at 20 degrees C is well described by a single exponential with a recovered initial anisotropy, r(eff)o, of 0.192 and an overall rotational correlation time for the protein, phi p, of 4.7 ns; r(eff)o = 0.214 and phi p = 4.2 ns for the FKBP12/FK506 complex. Using an expression for the order parameter squared, namely S2 = r(eff)o/rTo, where rTo is the vitrified steady-state excitation anisotropy, we recovered an S2 of 0.75 for W59 fluorescence in uncomplexed FKBP12 and S2 approximately equal to 1 in the FKBP12/FK506 complex. Results obtained for the FKBP12/rapamycin complex are similar to those found for the FKBP12/FK506 complex. Minimum perturbation mapping simulations were performed on the free and complexed forms of FKBP12 and the results were generally in agreement with the experimental data.

Emergence of penicillin resistant pneumococci in Sri Lanka

Two strains of penicillin resistant (PR) pneumococci were isolated recently from cerebrospinal fluid of two children with meningitis. Penicillin resistance was detected by using a lug disc of oxacillin in the Stokes disc diffusion method. The strains were tested quantitatively for sensitivity to penicillin by an agar dilution technique. The minimum inhibitory concentration (MIC) to penicillin of these strains were 2 micrograms/ml and 0.12 microgram/ml, indicating that respectively they were of frank and intermediate resistance to penicillin. However these strains were sensitive to other antibiotics tested, namely, erythromycin, tetracycline, chloramphenicol, amoxycillin, cephalexin and cefotaxime. Penicillin resistant pneumococci are here in Sri Lanka. Though one strain was of intermediate resistance, therapeutic failure during treatment with penicillin was evident in this case.

In vitro inhibition of marginal caries-like lesions with fluoride-containing amalgam

Carious lesions surrounding restorations represent one of the main causes of restoration failure. The addition of fluoride compounds to dental restorative materials prevents or reduces recurrent caries. The purpose of this study was to compare the capacity of three restorative materials to inhibit the development of recurrent caries in vitro. Thirty unrestored, noncarious premolars that were being extracted for orthodontic reasons were sectioned in half buccolingually and divided into three groups. One of the groups was restored with conventional amalgam. The second group was restored with a fluoride-containing amalgam, and the third group was restored with a glass-ionomer cement. All the samples were submitted to a medium containing Streptococcus mutans (Ingbritt strain) for 8 weeks. At the end of the 8-week incubation period, the samples were cut into 100 microns sections, soaked in Quinoline (IR = 1.62), and observed with light transmission and polarized light microscopy. The development of artificial caries in the cavity walls was measured in microns. The results show that conventional amalgam had an average caries penetration of 160 microns, fluoride-containing amalgam 46 microns, and glass-ionomer cement 11 microns. Glass-ionomer cement gave the best protection against recurrent caries.

Acceptance of a psychiatric screening questionnaire by general practice attenders

The general health questionnaire (GHQ) is a self-reporting psychiatric screening questionnaire which has been tested and validated in a number of languages and cultural settings. The translated and validated 30 item GHQ was given to a selected sample of women between 15 and 49 years attending a suburban general practice, as a part of a study on emotional disorder. The acceptance of the questionnaire was high with a compliance of 91.5% from those who were invited to participate. The majority of respondents showed much interest and willingness in filling in the questionnaire.

[Breast cancer in the pregnancy-puerperal cycle]

From 1978 to 1988, 611 cases of breast cancer were seen by the Mastology Department of the Beneficência Portuguesa Hospital in São Paulo, Brazil. Thirteen (2.12%) cases were associated to pregnancy, and nine (2.4%) became pregnant after treatment. The patients were submitted to surgery and the authors waited till the end of pregnancy to perform the Rt and/or Qt. Two cases could not be submitted to any kind of treatment. Whenever tests indicated fetal maturity, the option was to perform a caesarean section, and oophorectomy was performed in the most advanced cases. Among patients who became pregnant after treatment, initial cases were predominant and their pregnancies went to term with no problem. The authors compare their results to data found in literature and draw attention to anticonception in mastectomized patients.

[Microbiological study of salt (sodium chloride) of marine origin]

Foram analisadas 19 amostras de SAL (NaCl), tipo grosso, oriundas de diferentes salinas, para verificação da flora microbiana e presença de bactérias nocivas em Microbiologia Alimentar. O material apresentou grande contaminação por microrganismos saprófitas, bactérias aeróbias e anaeróbias, Gram positivas e negativas, proteolíticas, pigmentadas, esporuladas, leveduras e fungos. A alta incidência das bactérias halofílicas "vermelhas", responsáveis pela deterioração de carnes, pescados e outros produtos salgados foi estudada. A freqüência, em 15 amostras de SAL, de bactérias esporuladas termorresistentes foi calculada em 33%, possuindo um SAL germe termofílico. Para anaeróbios a positividade foi de 80%, havendo esporulação em 40% das culturas isoladas. Os índices para leveduras e fungos foram de 73% e 93%, respectivamente.