Emulating an RCT in observational research in chest trauma: The target trial approach

BACKGROUND

While the concept of a "target trial"-optimizing the quality of observational studies by attempting to emulate the ideal world conditions of a randomized controlled trial-was first expounded over a decade ago, the take up of this concept in the design and analysis of trials in trauma is lacking. The target trial approach avoids common errors in observational research to increase its scientific validity as well as potentially enable causal questions to be answered without the expense and intricacies of a randomized controlled trial. This review article briefly introduces the reader to the concepts and utility of a "target trial" approach before providing demonstrations of its application in the subject area of chest trauma.

METHODS

Four articles published in the last 5 years-two case control and two cohort studies-are chosen and considered in terms of their causal question; study population; inclusion and exclusion criteria; designation of time 0; clarity of the follow-up period; study outcomes; methods to minimize confounding; results; overall issues regarding study time; and the presence of avoidable errors such as introduction of immortal time bias or information bias.

RESULTS

Two of the studies had an unclear causal question; none of the studies designated a time 0; the follow-up period was unclear for all but one of the studies; and one study had a serious issue with information bias resulting from differential misclassification.

CONCLUSION

Failure to emulate a "target trial" framework may lead to serious methodologic issues in observational research. Expansion of the awareness of this approach in trauma literature will improve the quality of our observational research and potentially translate into significant benefits for our patients.

Assessment and Transplantation of Orphan Donor Livers: A Back-to-Base Approach to Normothermic Machine Perfusion

Globally, a large proportion of donor livers are discarded due to concerns over inadequate organ quality. Normothermic machine perfusion (NMP) allows for hepatocellular and biliary viability assessment prior to transplantation and might therefore enable the safe use of these orphan donor livers. We describe here the first Australasian experience of NMP-preserved liver transplants using a 'back-to-base' approach, where NMP was commenced at the recipient hospital following initial static cold storage. In the preclinical phase, 10 human donor livers declined for transplantation (7 from donation after circulatory death [DCD] and 3 from donation after brain death [DBD]) were perfused using a custom-made NMP setup. Subsequently, 10 orphan donor livers (5 from DCD and 5 from DBD) underwent NMP and viability assessment on the OrganOx metra device (OrganOx Limited, Oxford, United Kingdom). Both hepatocellular and biliary viability criteria were used. The median donor risk index was 1.53 (1.16-1.71), and the median recipient Model for End-Stage Liver Disease score was 17 (11-21). In the preclinical phase, 'back-to-base' NMP was deemed suitable and feasible. In the clinical phase, each graft met predefined criteria for implantation during NMP and was subsequently transplanted. Five (50%) recipients developed early allograft dysfunction based on peak aspartate aminotransferase. To date, all grafts function satisfactorily, and none of the 5 recipients who received a DCD liver have developed cholangiopathy. The OrganOx metra using a back-to-base approach has enabled the safe use of 10 high-risk orphan donor livers with 100% 6-month patient and graft survival. NMP improved surgeon confidence to use orphan donor livers and has enabled a safe expansion of the donor pool.

A New Enzyme Immunoassay for Soluble Fibrin in Plasma, with a High Discriminating Power for Thrombotic Disorders

Fibrin formation is a multistep process initiated by thrombin. At first thrombin converts fibrinogen to fibrin molecules which in vivo form soluble complexes with fibrinogen. Soluble fibrin is considered to be an early biochemical marker for intravascular fibrin formation and impending thrombotic events, such as deep venous thrombosis (DVT), pulmonary embolism (PE) and disseminated intravascular coagulopathy (DIC).

A new enzyme immunoassay (EIA) was developed on the basis of a monoclonal antibody directed against a fibrin specific neo-epitope located on the gamma-chain of fibrinogen; γ-(312-324). In addition, it was possible to prepare a lyophilized reference material of thrombin-generated soluble fibrin, that allowed for full antigen recovery after reconstitution with buffer. Assay conditions, e.g. solid phase-Ig concentration and buffer composition, sample and conjugate dilution, and incubation times were optimised.

The present assay was found to be specific (no interference of homologous antigens) and reproducible (intra-assay CV 4-8%, inter-assay CV 4-9%), and therefore highly suited for measuring soluble fibrin levels in a plasma milieu. The median normal value for soluble fibrin was determined in plasma samples obtained from apparently healthy volunteers (n = 81) and found to be 0.040 μg/ml, with a range (10-90 percentiles) of 0.026-0.059 μg/ml.

A retrospective study showed that soluble fibrin levels were highly significantly increased in patients with a confirmed diagnosis of DIC (median 1.042 μg FEU/ml, range 0.160-2.319 μg/ml, n = 21, P <0.0001 vs normal), PE (median 0.527 μg FEU/ml, range 0.084-1.234 μg/ml, n = 29, P <0.0001 vs normal) and DVT (median 0.126 μg FEU/ml, range 0.059-0.878 μg/ml, n = 36, P <0.0001 vs normal), as determined by the Mann-Whitney U-Test.

Why I like nocturnal dialysis

As with most things in life, this form of treatment is not for everybody. In my opinion, it is an option that should be explored if it is available. I have come to the conclusion that the advantages of nocturnal hemodialysis outweigh any of the possible disadvantages that there is no decision to make. My quality of life is so much better that I cannot envision going back to standard treatments. This is something that each patient will have to decide for themselves. Nocturnal dialysis has changed my life. For the better, even better than the few years of transplant, for this I thank my doctors, nurses and everyone else who has helped me along the way.

Clinical features and diagnosis of 42 travellers with cutaneous leishmaniasis

BACKGROUND

Leishmania species that occur within different geographical areas may cause different clinical manifestations, virulence and drug sensitivity. Patients/Methods. All patients with a clinical diagnosis of cutaneous leishmaniasis seen at the Hospital for Tropical Diseases from 1997 to 2000 were identified and clinical details recorded onto a database, with emphasis on clinical presentation, risk factors, travel history and laboratory diagnosis.

RESULTS

Forty-two patients were identified, 23 of whom had travelled to New World and 19 to Old World countries. Clinical presentation typically consisted of a single nodule with ulceration. In 50% infection was caused by L. (Viannia) braziliensis. PCR was performed in specimens from 34 patients and species identification was possible in 32 cases (sensitivity 94%), the two PCR negative patients had amastigotes demonstrated by histology and culture. Patients were treated with established therapies. Seventy one percent were cured by treatment, 12% had a spontaneous cure, 7% were lost to follow-up and the remaining 10% required a second-line therapy. No relapses were reported during a mean follow-up period of 27 months.

CONCLUSIONS

Our study highlights the need for comprehensive investigations and the advantages of PCR in the diagnosis of patients with suspected leishmaniasis in non-endemic regions of the world.

The public health response to a case of Lassa fever in London in 2000

OBJECTIVES

Evaluation of the Department of Health 1996 guidance, the Memorandum on the Management and Control of Viral Haemorrhagic Fevers.

METHODS

Description of the public health management in 2000 of the fifth UK patient confirmed to have Lassa fever.

RESULTS

Delayed risk categorisation of the patient occurred for a variety of reasons. DH Guidance was followed once infection control advice was sought. Active surveillance of 125 contacts was extremely resource intense, involving over 3000 communications. Self-monitoring by healthcare workers should be considered in future. Advice on use of ribavirin prophylaxis is not included in the Memorandum, nor advice or templates for information sheets for contacts. Information sheets are now available from the Health Protection Agency in the event of future cases. International aspects not adequately addressed include the need for reliable risk assessment to be carried out before patients are medically evacuated from the country of origin, and the steps required to repatriate UK nationals. Effective and efficient communication is required between national and international organisations involved in such incidents.

CONCLUSIONS

If guidelines are unclear or impracticable they will not be followed. It is important that lessons are learned and documented and that national guidance be regularly reviewed.

Prenatal diagnosis from fetal urine in bladder outlet obstruction: success rates for traditional cytogenetic evaluation and interphase fluorescence in situ hybridization

PURPOSE

To determine the optimal approach to the prenatal chromosome analysis of fetal urine from fetuses with bladder outlet obstruction.

METHODS

Retrospective evaluation of traditional cytogenetic and interphase fluorescence in situ hybridization (FISH) analysis on fetal urine specimens from fetuses with bladder outlet obstruction.

RESULTS

Traditional cytogenetic analysis was successful on 71 (95%) of 75 samples, and FISH was informative on 20 (65%) of 31 specimens. The combination of traditional cytogenetic analysis and FISH yielded a 96% diagnostic success rate. The mean turnaround time was 8 days (range 5-14) for traditional cytogenetic analysis and 1.6 days (range 1.0-4.0) for FISH. Chromosome abnormalities were detected in 6 (7.9%) of 76 pregnancies.

CONCLUSION

Traditional cytogenetic analysis achieves a high success rate (95%) and is superior to FISH for chromosome evaluation of fetal urine. However, FISH, when informative, can complement traditional cytogenetics as it will expeditiously rule out common trisomies in fetuses with bladder outlet obstruction.

Angiotensinogen genotype, plasma protein and mRNA concentration in isolated systolic hypertension

Isolated systolic hypertension (ISH) occurs predominantly in the elderly, with a considerable morbidity and mortality. Its etiology is unknown but is likely to involve a significant genetic component. The aim of this study was to examine the angiotensinogen gene in ISH. The M235T and G(- 6)A polymorphisms were genotyped by polymerase chain reaction (PCR) in 86 ISH patients and 120 normotensive controls. Plasma angiotensinogen concentration was determined in 198 subjects by an indirect radioimmunoassay technique. Angiotensinogen mRNA concentration was determined by quantitative competitive reverse transcription (RT)-PCR in subcutaneous adipose tissue from a subset of these patients (n = 8) and controls (n = 6). Both the M235T (p = 0.0015) and G(- 6)A (p = 0.029) polymorphisms were associated with ISH. Plasma angiotensinogen concentration was higher in patients than controls (p < 0.0001), but was not associated with genotype. Angiotensinogen mRNA concentration in adipose tissue from ISH subjects was significantly lower than in adipose tissue from normotensive subjects (p = 0.033). The association of angiotensinogen gene variants with ISH and the elevation of plasma angiotensinogen concentration in these patients suggests a role of the angiotensinogen gene in this form of hypertension. Angiotensinogen gene expression may be altered in ISH, but this requires further examination.

Prenatal diagnosis from cystic hygroma fluid: the value of fluorescence in situ hybridization

OBJECTIVE

We sought to determine the optimal approach to the prenatal chromosome analysis of cystic hygroma fluid using traditional cytogenetic analysis and fluorescence in situ hybridization.

STUDY DESIGN

A retrospective evaluation of our experience with traditional cytogenetic and fluorescence in situ hybridization analysis on cystic hygroma fluid was performed through a systematic review of the Genzyme Genetics database from January 1995 to July 2000. Information on gestational age, sample volume, clinical ultrasound findings (including fetal viability), cytogenetic results, fluorescence in situ hybridization results, and turn-around-time were queried.

RESULTS

Eighty-three specimens were included in the investigation. The mean gestational age was 18.1 weeks (range, 13-27 weeks), and the mean sample volume was 20.7 mL (range, 0.1-101 mL). Of the 72 samples in which > 5 mL of cystic hygroma fluid was available, the success rate for cytogenetic analysis was 76% (55/72 samples). In 11 specimens of < or = 5 mL of cystic hygroma fluid, cytogenetic analysis was successful in only 1 case (9%). Fluorescence in situ hybridization was attempted on 23 samples, 18 of which were successful (78%), including 6 of 9 cases of cell culture failure (67%). Both traditional cytogenetic analysis and fluorescence in situ hybridization were performed in 21 instances when a sample of > 5 mL was available. A successful result was obtained by either cytogenetic testing or fluorescence in situ hybridization analysis or both in 19 of 21 of these cases (90%). Samples of > 5 mL from viable fetuses had a higher cytogenetic success rate (80%) and fluorescence in situ hybridization success rate (89%) than samples from fetuses with intrauterine death (38% and 50% cytogenetic and fluorescence in situ hybridization success rates, respectively.) The mean turn-around time was 8.2 days (range, 4-17 days). Results were available in < or = 12 days in 91% of cases. There was a 91% aneuploidy rate identified, with 45,X occurring in 86% of the samples.

CONCLUSION

We conclude that the optimal approach for the prenatal diagnosis of chromosome abnormalities from cystic hygroma samples is to perform both traditional cytogenetic studies and interphase prenatal fluorescence in situ hybridization evaluation for the most common aneuploidies that involve chromosomes 13, 18, 21, X, and Y. With this combined approach, our data indicate that, in viable pregnancies with a fluid sample of >5 mL, a 90% diagnostic success rate can be achieved.

A new enzyme immunoassay for soluble fibrin in plasma, with a high discriminating power for thrombotic disorders

Fibrin formation is a multistep process initiated by thrombin. At first thrombin converts fibrinogen to fibrin molecules which in vivo form soluble complexes with fibrinogen. Soluble fibrin is considered to be an early biochemical marker for intravascular fibrin formation and impending thrombotic events, such as deep venous thrombosis (DVT), pulmonary embolism (PE) and disseminated intravascular coagulopathy (DIC). A new enzyme immunoassay (EIA) was developed on the basis of a monoclonal antibody directed against a fibrin specific neo-epitope located on the gamma-chain of fibrinogen; gamma-(312-324). In addition, it was possible to prepare a lyophilized reference material of thrombin-generated soluble fibrin, that allowed for full antigen recovery after reconstitution with buffer. Assay conditions, e.g. solid phase-Ig concentration and buffer composition, sample and conjugate dilution, and incubation times were optimised. The present assay was found to be specific (no interference of homologous antigens) and reproducible (intra-assay CV 4-8%, interassay CV 4-9%), and therefore highly suited for measuring soluble fibrin levels in a plasma milieu. The median normal value for soluble fibrin was determined in plasma samples obtained from apparently healthy volunteers (n = 81) and found to be 0.040 microg/ml, with a range (10-90 percentiles) of 0.026-0.059 microg/ml. A retrospective study showed that soluble fibrin levels were highly significantly increased in patients with a confirmed diagnosis of DIC (median 1.042 microg FEU/ml, range 0.160-2.319 microg/ml, n = 21, P<0.0001 vs. normal). PE (median 0.527 microg FEU/ml, range 0.084-1.234 microg/ml, n = 29, P<0.0001 vs normal) and DVT (median 0.126 microg FEU/ml, range 0.059-0.878 microg/ml, n = 36, P<0.0001 vs. normal), as determined by the Mann-Whitney U-Test.

A hospital/school science fair mentoring program for middle school students

The Massachusetts General Hospital (MGH) and the James P. Timilty Middle School established a partnership to enhance science education, promote faculty development, and improve the health status and academic performance of all Timilty students. This article describes one of the Partnership's Science Connection programs, the Science Fair Mentoring Program, designed to enhance middle school science education, inform urban early adolescents about professions in the health field, inspire them to pursue postsecondary study in the health sciences, and prepare them for rigorous academic work in high school. In this program, hospital-based clinical and research staff mentor young adolescent students. The authors describe the planning, implementation, and evaluation of the Science Fair Mentoring Program as an innovative learning experience.

Impaired glucose tolerance is normalized by treatment with the thiazolidinedione troglitazone

OBJECTIVE

The primary purpose of this study was to assess the effects of 12 weeks of treatment with either troglitazone, an investigational thiazolidinedione that acts as an insulin-action enhancer, or placebo in patients with impaired glucose tolerance (IGT).

RESEARCH DESIGN AND METHODS

A total of 51 subjects with IGT between 24 and 77 years of age were enrolled in this multicenter, double-blind, placebo-controlled, parallel group study (troglitazone, 25 patients; placebo, 26 patients). Patients were randomly assigned to receive either 400 mg troglitazone (every morning [QAM]) or placebo (QAM). The main outcome measure was the oral glucose tolerance test (OGTT) assessing glucose, insulin, and C-peptide levels in the fasting state and every 30 min up to 2 h after ingesting the glucose load. Fasting serum levels of HbA1c, fructosamine, lipids, and blood pressure were also measured.

RESULTS

A total of 46 patients completed the study. The glucose, insulin, and C-peptide responses after a glucose load were significantly reduced at 6 and 12 weeks in the troglitazone treatment group. After 6 weeks of treatment, 75% (n = 18) of those taking troglitazone had improved to normal glucose tolerance, whereas only 38% (n = 9) of those of placebo showed improvement (P = 0.008). After 12 weeks of treatment, 80% (n = 16) of the troglitazone treatment group had normalized their glucose tolerance, while only 48% (n = 10) of those on placebo had converted to normal (P = 0.016). Fasting triglyceride levels in the troglitazone treatment group had decreased by 40 mg/dl (0.45 mmol/l) (P = 0.0016). Other lipid measurements, blood pressure, glycosylated hemoglobin, and fructosamine were normal at baseline for both treatment groups and remained normal throughout the study.

CONCLUSIONS

The glycemic response after a glucose load is statistically and clinically significantly improved for patients with IGT treated with troglitazone.

The impact of healthcare trends on imaging products and services

Key factors in healthcare reform--cost, access to care and quality of care--all have implications for diagnostic imaging. Technology is moving rapidly toward being able to provide images quickly, frequently in digital form to radiologists located in other departments or offsite. Film-based imaging still provides the highest resolution currently available and is the most appropriate option for many situations, such as mammography. Hybrid systems that combine film-based capture with electronic image storage and delivery have also been introduced for situations that require simultaneous review by remote clinicians. Healthcare systems will demand equipment that features open architecture and adheres to industry standards. Healthcare providers will form alliances with imaging equipment and consumable suppliers whose products and services offer advantages in quality, productivity and efficiency that lead to an overall decrease in costs.

Glycosylation of Asn397 or Asn418 is required for normal insulin receptor biosynthesis and processing

Two N-linked sites of glycosylation in the insulin receptor were examined for their contribution to insulin binding, tyrosine kinase activity, and receptor biosynthesis. Asn397 and Asn418 were replaced by Gln using site-directed mutagenesis either as single mutations, i.e., Q-397 and Q-418, or as a double mutation in which both sites were removed (Q-D). The mutations were transiently expressed in COS cells and the findings compared with cells that transiently expressed the wild-type human insulin receptor. Q-397 and Q-418 mutant insulin receptors had insulin-binding characteristics similar to the wild-type human insulin receptor, whereas no insulin-binding activity could be detected above the control level in cells transfected with Q-D. Flow cytometry with antibodies against the human insulin receptor indicated the presence of Q-397, Q-418, and wild-type human insulin receptors in the surface of COS cells and failed to demonstrate a Q-D receptor. Insulin-induced autophosphorylation was similar in Q-397, Q-418, and wild-type human insulin receptors as was their ability to phosphorylate an artificial substrate, poly Glu-Tyr (4:1). Our inability to detect Q-D receptors was not caused by a lack of Q-D mRNA. COS cells transfected with Q-D cDNA generated as much Q-D mRNA as the amount of wild-type human insulin receptor mRNA present in cells transfected with wild-type receptor cDNA. Finally, pulse-chase experiments with [35S]Met were able to detect 190,000-M(r) proreceptors and the alpha-subunits for Q-397, Q-418, and wild-type human insulin receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Exchanging sex for crack-cocaine: a comparison of women from rural and urban communities

Studies of the HIV risks of crack-cocaine using women have focused on those living in the inner city, urban areas of the country. However, reports indicate that the rates of syphilis and HIV infection have shown greater increases in rural areas than in urban ones. This paper reports the findings of a comparative study of 60 female crack-cocaine users, 25 from rural southeast Georgia and 35 from Miami, Florida, to determine their drug using and sexual practices, as well as their knowledge about AIDS and HIV transmission. Their patterns of initial and continuous drug use were similar, as were their sexual practices. However, the Miami women were more likely to have had a greater number of sexual partners than the Georgia women. Both groups were knowledgeable about AIDS and the transmission of HIV, yet all participated in activities that put them at high risk for HIV infection and transmission. Some 12 percent of the 60 respondents reported testing positive for HIV. The study suggests that at least within these populations, there are few differences between rural and urban crack using women in terms of their crack use, sexual practices, and potential for HIV infection and transmission.

The role of the family in psychiatric rehabilitation

This article describes the multiple roles that families can play in the psychiatric rehabilitation process and suggests ways for professionals to collaborate with them. The authors discuss the family's experience of loss and their process of recovery; their caregiving role; their role in supporting other families; their teaching and educational role; their advocacy role; their role as researchers and research subjects; and some suggestions for supporting family roles.

The bicycle path to Rome

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Abnormal chromosome complement resulting from a familial inversion of chromosome 2

It has been suggested that pericentric inversions of chromosome 2 increase the risk for spontaneous abortion but do not increase the risk for unbalanced recombinant offspring. We report our experience of a familial pericentric inversion of chromosome 2 resulting in two unbalanced recombinant offspring. Both subjects have 46,XX,rec(2),dup q,inv(2)(p25q35).

Familial translocation t(9;16)

We report a female with a deletion of 9p and concomitant duplication of 16q [46,XX,-9,+der(9),t(9;16)(p24;q13)]. Parental chromosome analysis showed a balanced maternal translocation [46,XX,t(9;16)(p24;q13)]. Three other cases of translocations involving chromosomes 9 and 16 have been reported, one of them with identical breakpoints. A review of published reports of deletion 9p and duplication 16q is presented, and a comparison is made with previously described cases.

Sensitisation by mycobacteria and the effects of BCG on children attending schools in the slums of Bombay

Quadruple skin testing with new tuberculins was used to evaluate the effects of previously administered BCG Madras in children attending schools in the slums, or living in Kopri Leprosy Colony in Bombay. There were differences between schools both in the level of sensitisation of children without BCG scars and in the effects of BCG vaccination. Results obtained at one school resembled those obtained in a previous study in Agra, where BCG was thought to be ineffective. Results from the other schools and Kopri were more like those previously reported from Ahmednagar, where BCG was considered to be much more effective. Thus within the same city groups of children of the same social status may vary widely both in their contact with mycobacteria and in their capacity to benefit from BCG vaccination.

Chromosome subband 17p11.2 deletion: a minute deletion syndrome

Interstitial deletion of the short arm of chromosome 17 was detected in three unrelated patients with mental retardation and multiple congenital malformations. These patients were identified at a single centre over a six month period suggesting that del(17) (p11.2p11.2) is not a rare constitutional chromosome rearrangement. Comparison of the phenotypic features in a total of 19 patients with del(17)(p11.2p11.2) shows a consistent clinical phenotype with moderate to severe mental retardation, microbrachycelphaly, prominent forehead, broad face, flat midface, prognathism, short, broad hands, and behavioural anomalies such as self-mutilation. The sex ratio is unremarkable, parental ages are normal, and survival is usually unimpaired. Chromosome resolution of at least 500 bands appears necessary to detect this deletion.

The diabetes care and education provided by nurses working in physicians' offices

This paper describes the diabetes care and education provided to 290 diabetic patients by 47 nurses working in primary care physi cians' offices in two Michigan communities. The study utilized data from questionnaires and logbooks of patient contacts kept by the 47 nurses. The study demonstrated that nurses could play an important role in caring for persons with diabetes, but in dicated that office nurses were constrained from delivering optimal care by lack of time, resources, and diabetes-related continuing education. Since the majority of patients with diabetes receive their ongoing diabetes care and education in primary care physicians' offices, and since nurses, as a profession, can and should play a major role in the overall care of these patients, a national effort to improve the quality of patient education provided by this very large group ofhealth professionals is indi cated. The diabetes patient education provided by office nurses should supplement, but not replace, the comprehensive diabetes patient education provided by programs that meet national standards.

New common fragile sites

We report the finding of a large number of new common fragile sites. Thirty-one (56%) of 55 common fragile sites found in a sample of human lymphocytes were ones not described at the Eighth International Workshop on Human Gene Mapping (HGM 8). The sample consisted of 3023 lymphocytes from nine unrelated individuals with a history of genitourinary malignancy. The lymphocytes were challenged in culture with aphidicolin (Apc), fluorodeoxyuridine (FUdR), 5-azacytidine (Aza), and bromodeoxyuridine (BrdU). Thirteen of the new common fragile sites were induced by Apc and FUdR, nine by Aza, five by BrdU, and four by combined means. The sites induced by Apc and FUdR were cross-induced by BrdU. The fragile sites induced by a diminished concentration of Aza were largely located in heterochromatic regions and were cross-induced by BrdU and FUdR. Exposure to BrdU for 24 hours, a technique hitherto restricted to rare fragile sites, induced several common fragile sites. Control lymphocytes had far fewer gaps and breaks, but these were clustered predominantly at high-expression fragile sites. Because more than half of the common fragile sites in this study were new, it is clear that much remains to be learned. Because the classes of fragile sites reveal cross-induction, we propose that fragile sites share structures in DNA.

Effect of a sulfonylurea and insulin on energy expenditure in type II diabetes mellitus

Previous studies demonstrated that administration of insulin and oral hypoglycemic agents tends to produce weight gain in type II diabetic patients. The goal of this study was to determine the potential contribution of changes in metabolic rate and urinary glucose excretion to changes in energy balance associated with treatment with glyburide and insulin. Six obese type II diabetic patients (52-61 yr old; 123-214% of ideal weight) were fed a weight-maintaining diet of fixed composition and caloric content in a Clinical Research Center. The mean fasting plasma glucose concentrations were 10.7 +/- 1.3 (+/- SE) mmol/L before treatment, 7.9 +/- 1.4 mmol/L at the end of 2 weeks of glyburide treatment, and 5.2 +/- 0.3 mmol/L at the end of 2 weeks of insulin treatment. Urinary glucose excretion decreased from 48 +/- 19 g/day before treatment to 20 +/- 9 g/day at the end of glyburide treatment and 2 +/- 1 g/day at the end of insulin treatment. Neither treatment affected mean postabsorptive resting metabolic rate (untreated 4.86 +/- 0.50 kJ/min; glyburide-treated, 4.63 +/- 0.45 kJ/min; insulin-treated, 4.70 +/- 0.46 kJ/min) or postprandial resting metabolic rate (untreated, 5.71 +/- 0.55 kJ/min; glyburide-treated, 5.60 +/- 0.39 kJ/min; insulin-treated, 5.70 +/- 0.51 kJ/min). However, the two patients with the largest decreases in urinary glucose excretion also had decreases in energy expenditure. These data indicate that many obese type II diabetic patients could have significant weight gain from reduced energy losses alone.

Fragile sites and genitourinary tumors

We tested for fragile sites in lymphocytes from nine patients with genitourinary tumors to determine if a correlation existed between their cancer chromosome breakpoints and fragile sites. Induction was done for rare fragile sites in all known classes by exposure of cells to fluorodeoxyuridine and bromodeoxyuridine (BrdU). No rare fragile sites were found. Induction was also done for common fragile sites in all known classes using aphidicolin (Apc), 5-azacytidine, and BrdU. Although 56 common fragile sites were detected, only a single site corresponded in location to a genitourinary tumor chromosome breakpoint. That was the common fragile site in band 3p14. No overall correlation was found between fragile sites and chromosome rearrangements in carcinoma of the kidney, ureter, bladder, and testis. The sole known candidate for a possible biologic role is the 3p14 common fragile site in renal cell carcinoma.

Expression and characterization of hepatitis B virus precore-core antigen in E. coli

The hepatitis B virus core antigen, including the precore sequence (HBcAg-p25), was expressed at very high levels in bacteria. Three expression vectors were constructed in which the synthesis of HBcAg-p25 was controlled by the tac promoter, and the number of nucleotides between the bacterial ribosome binding site and the precore initiation codon was varied in order to maximize HBcAg-p25 synthesis. The relative amount of HBcAg-p25 polypeptide expressed by the different vectors was estimated by SDS-polyacrylamide gel electrophoresis and immunoblot. HBcAg-p25 was associated with an insoluble fraction of bacterial extracts and required ionic detergents for solubilization. Comparison by ELISA of the immunoreactivity of HBcAg with and without the precore sequence suggested that human anti-HBcAg IgG preferentially recognizes HBcAg lacking the precore sequence.

The effects of cyclosporin A on the early responses of B and T cells to Epstein-Barr virus infection

The immunosuppressive properties of the fungal metabolite Cyclosporin A (CsA) on the human lymphocyte response to the polyclonal B cell activator Epstein-Barr virus (EBV) in vitro were assessed. CsA showed both stimulatory and inhibitory effects on EBV-induced IgM secretion, the net effect being dependent on the dose of virus used. T cells were required for both these effects to occur. A model is proposed to account for the complex interactions of CsA in this system.

The biggest problem in diabetes

An assessment of the big gest problem in diabetes care from the viewpoint of 115 health care profes sionals and 428 diabetic patients was obtained. There was substantial agreement by health pro fessionals and patients alike that diet and diet- related issues constituted the most difficult problem faced by persons with diabetes and by health professionals caring for those persons. These find ings may be important in organizing diabetes patient education and in the selection of research efforts within the overall field of diabetes.

Development of a guide to recommended audiovisual materials on diabetes, 1983

The task of reviewing and critiquing the hundreds of audiovisual programs available for diabetes education is an exceedingly time consuming and tedious activity. To assist the many users of educational audiovisual materials the Outreach Core of the Michigan Diabetes Research and Training Center undertook the review and critique of these programs. Based on specified selection and review cri teria, 35 programs have been chosen for inclusion in a booklet entitled "Recommended Audiovisual Re sources for Diabetes Education. " This booklet is available to any diabetes educator upon request.

Training the disabled for income generating activities

The main aim of the paper is to look at the general situation in which many handicapped persons find themselves and to suggest ways in which trainers can help by training the handicapped without thinking in terms of attending "traditional" training courses. The ultimate aim of the trainer is to help handicapped persons to stand on their own, be productive within society and be engaged in gainful activities, even though this may not necessarily involve them working formally in a factory or similar enterprise.

Adverse effects of liquid protein fast on the handling of magnesium, calcium and phosphorus

We have studied the effect of a vitamin- and potassium-supplemented liquid protein fast on mineral metabolism of six obese subjects (five women, 1 man) for 40 days. Each patient was admitted to a metabolic ward and was given daily 300 Kcal, 75 mg of calcium, 406 mg of phosphorus, 7 mg of magnesium, 33 meq of potassium, and 11.5 g of nitrogen. Urinary calcium, phosphorus and magnesium levels were greatest during the first week, but decreased as the fast continued to 21, 31 and 300 percent, respectively, above intake. Cumulative urinary losses of calcium, phosphorus and magnesium were 58, 75 and 500 percent greater, respectively, than the cumulative intake. Fecal losses for calcium, phosphorus and magnesium were less than urinary losses throughout the study. Cumulative fecal losses of magnesium were more than 30 percent greater than dietary intake. Mean daily balances were -104 mg (calcium), -48 mg (magnesium) and -363 mg (phosphorus). Serum phosphorus and magnesium levels did not change. However, serum calcium levels decreased (-0.5 mg/dl, p less than 0.05). Serum bicarbonate levels decreased 20 percent during the first 8 days of the fast, at which time urinary ammonium was maximal, but later returned to control values despite sustained increases in serum and urinary acids throughout the fast. Ammonium excretion was 260 to 300 percent above control values. Urinary titratable acid excretion was greatest early in the fast but subsequently decreased as the excretion of phosphorus declined. Titratable acid accounted for less of the excreted acid (7 to 21 percent) than did ammonia (70 to 90 percent). It is concluded that a liquid protein fast results in negative mineral balance that is not reflected by serum values and is due primarily to renal losses. The losses of magnesium were proportionally greater than those of calcium and phosphorus. These studies indicate that a liquid protein fast results in depletion of the intracellular and/or skeletal stores of these minerals.

Detection of extracellular toxin(s) produced by Vibrio vulnificus

Conditions are described for the production, in high titers, a heat-labile, antigenic, extracellular toxin(s) by Vibrio vulnificus, a recently recognized human pathogen. Bacteriologically sterile culture filtrate preparations obtained from mid-logarithmic-phase cultures of the bacterium possessed cytolytic activity against mammalian erythrocytes, cytotoxic activity for Chinese hamster ovary cells, vascular permeability factor activity in guinea pig skin, and lethal activity for mice. The specific activity of toxin preparations from cultures of a virulent strain of the bacterium was ca. 25-fold more than that of toxin preparations obtained from cultures of a weakly virulent strain. The four toxic activities were inseparable by gel filtration with Sephadex G-100; however, two components, which had markedly different elution behavior but which possessed the four activities mentioned above, were obtained. The major (ca. 88% of the recovered activity) and minor components had apparent molecular weights of ca. 38,500 and greater than 150,000, respectively.