Troglitazone inhibits progesterone production in porcine granulosa cells

Troglitazone (a thiazolidinedione that improves insulin resistance) lowers elevated androgen concentrations in women with polycystic ovarian syndrome. In this study, we assessed the direct effects of troglitazone on steroidogenesis in porcine granulosa cells. Troglitazone inhibited progesterone production in a dose- and time-dependent manner (earliest effects at 4 h, maximum at 24 h) without affecting cell viability. Progesterone production was also inhibited by troglitazone in the presence of 25-hydroxycholesterol, indicating that the drug does not affect intracellular cholesterol transport. Troglitazone also inhibited FSH- and forskolin-stimulated progesterone secretion. The reduced progesterone production was accompanied by marked elevations of pregnenolone concentrations, suggesting inhibition of 3beta-hydroxysteroid dehydrogenase (3beta-HSD). The activity of 3beta-HSD in troglitazone-treated granulosa cells was decreased by more than 60%, compared with controls after 24 h. Troglitazone did not affect aromatase activity in porcine granulosa cells. In summary, troglitazone has direct effects on porcine granulosa cell steroidogenesis. The drug specifically inhibits 3beta-HSD activity, resulting in impaired progesterone production. The clinical relevance of this direct in vitro effect on steroidogenesis needs further investigation.

The origin of red blood cell biopterin

Data are presented to support the hypothesis that the biopterin content of red blood cells arises during erythropoiesis. Only when the plasma concentration rises above the erythrocyte concentration of biopterin is there likely to be diffusion into the cell.

Functional characterization and exon 2-intron 2-exon 3 gene sequence of HLA-B*2712 as found in a British family

The HLA-B*27 group of alleles has been extensively studied due to the association of particular B*27 alleles with ankylosing spondylitis (AS). We describe here an HLA-B*27 allele (B*2712) encoding an antigen that lacks reactivity with B27 monoclonal antibodies (moabs) and alloantisera but reacts with some B40/B60 moabs and alloantisera and expresses the Bw6 public epitope. This allele was discovered by the segregation of an HLA-B allele undetectable by PCR-SSP within a Caucasian family from the British population referred for routine bone marrow transplant HLA typing and found in the haplotype A*29; B*2712; Cw*1203; DRB1*13; DQB1*0603. Serological typing showed a lack of reactivity with four B27 moabs and four alloantisera but positive reactivity with moabs and alloantisera specific for B40/B60 and Bw6 public epitopes. Subsequent sequencing showed the closest homology was with B*2708 with three mismatches in exon 2 at positions 204, 209 and 210. The intron 2 sequence was identical with other B*27 lineage alleles including a 2 base pair deletion at positions 95 and 96. The relationship between HLA-B*2712 and reported B60 associations with susceptibility to AS remains to be determined.

Milk consumption, galactose metabolism and ovarian cancer (Australia)

OBJECTIVES

It has been suggested that increased exposure to galactose, due to high consumption of dairy foods or reduced galactose metabolism, is associated with the development of ovarian cancer. We have investigated this in a large case-control study conducted in three Australian states between 1990 and 1993.

METHODS

Approximately 800 histologically-confirmed cases, 800 community controls and 300 controls recruited through breast-screening clinics completed dietary questionnaires. Approximately 100 cases and all breast-screening controls also provided a blood sample for analysis of galactose-1-phosphate-uridyltransferase (GALT).

RESULTS

Ovarian cancer risk was positively associated with increasing consumption of whole milk and other full-fat dairy foods, but was not associated with consumption of low-fat dairy foods and was inversely related to consumption of skimmed milk. There was no association between ovarian cancer and GALT except among women with abnormally low GALT who had a non-significant 2.5-fold increased risk of ovarian cancer.

CONCLUSIONS

These data do not support the hypothesis that galactose plays a major role in the development of ovarian cancer and suggest that reported associations between milk consumption and ovarian cancer are due to the fat content of milk and not to lactose or galactose. An increased risk of ovarian cancer in women with abnormally low levels of GALT cannot, however, be ruled out.

Relationship between number of ovulatory cycles and accumulation of mutant p53 in epithelial ovarian cancer

BACKGROUND

It has been suggested that increased numbers of ovulations might increase the risk of p53 gene (also known as TP53) mutation in the ovarian epithelium, thereby leading to the development of cancer. The data supporting this hypothesis have come from an observation that accumulation of p53 protein in epithelial ovarian cancer was strongly associated with increasing numbers of ovulatory cycles. We have further investigated the association between ovulatory history and p53 gene mutation by use of data from a large case-control study of ovarian cancer in Australia.

METHODS

Tissue blocks were available for immunohistochemical analysis of p53 protein from 234 case subjects, aged 18-79 years, who had invasive epithelial ovarian cancer. Epidemiologic data were also available for these women and for 855 control subjects. Case-case comparisons were made by use of prevalence ratios and 95% confidence intervals (CIs), and case-control comparisons were made by use of odds ratios (ORs) and 95% CIs. All statistical tests were two-sided.

RESULTS

There was no association between p53 accumulation and years of ovulation. Women with p53-positive cancers had undergone an average of 29.3 years of ovulation compared with 29.0 years of ovulation for women with p53-negative cancers (P=.8). Although the overall risk of ovarian cancer development was significantly increased in women who had undergone more years of ovulation (OR=2.17; 95% CI =1.54-3.05-for > or =35 years versus <23 years of ovulation), there was no difference in the risk associated with p53-positive and p53-negative cancers.

CONCLUSIONS

These results confirm the association between increased ovulation and ovarian cancer risk but do not support the hypothesis that this association is due to an increased risk of p53 mutation with a greater number of ovulatory cycles.

Action STAT! The crisis nurse

To provide quality care with limited staff and create a safer environment, managers created a new "crisis nurse" position.

Population screening for neonatal liver disease: a feasibility study

BACKGROUND

Extra-hepatic biliary atresia and several other causes of neonatal liver disease carry high mortality and morbidity rates, especially if not treated early in life. Despite professional recommendations, delayed referral of infants with prolonged jaundice continues to be a significant problem. One approach to reducing the age of referral and diagnosis is population screening to detect significant conjugated hyperbilirubinaemia as an index of liver dysfunction.

METHODS

To investigate this possibility, and to provide reference data on bilirubin and its conjugated and unconjugated fractions in a normal newborn population, 1157 neonates were anonymously tested (median age 7 days, range 4-28 days) using surplus plasma from routinely collected neonatal screening specimens, using dry slide chemistry.

RESULTS

Of 2310 specimens received, 50% were suitable for analysis. The remainder were either haemolysed or insufficient (10% and 40% of the total, respectively). Total bilirubin concentrations ranged from 9 to 428 micromol/l and conjugated bilirubin from 0 to 175 micromol/l, although the latter was rarely increased to more than 30 micromol/l (2.5th-97.5th percentile ranges 15-285 micromol/l and 0-18 micromol/l, respectively). The range of the percentage of conjugated bilirubin was 0-57% (2.5th-97.5th percentile; range 0-20%).

CONCLUSION

An increased conjugated bilirubin, expressed as a concentration or as the percentage of the total bilirubin, could be used as a specific marker to screen for liver dysfunction in neonates. This approach has the potential to improve the age of referral and the prognosis of infants with neonatal liver disease.

The primordial mind and the work of the negative

This paper was given at the celebration of Bion's centennial in 1997. At the request of the organisers of this conference, the work of Bion has been brought into perspective with the author's. The author has chosen to illumine Bion's concept of the primordial mind and considers the transformation of the beta-elements into the alpha ones. He also refers to Bion's distinction of thoughts without thinker and thinking as needing thoughts to be thought by a thinker (thinking apparatus). The main point of the paper is Bion's opposition of 'nothing' and 'no thing'. The author refers to Freud's paper on 'Negation'. He recalls his own model of the double limit. He tries to show how Freud's conception of representation has a much wider field than is usually stated. He emphasises differences between Freud's and Bion's 'basic assumptions'. After having tried to clarify Bion's ideas on 'O', 'K and -K', he recalls Bion's reference to Keats's negative capability. The author then gives a short account of his own concept of the 'work of the negative', finding correspondences with Bion's own concepts. As a conclusion two Indian myths are recalled for their great symbolic value.

Alteration of zif268 zinc-finger motifs gives rise to non-native zinc-co-ordination sites but preserves wild-type DNA recognition

Zinc fingers are among the major structural motifs found in proteins that are involved in eukaryotic gene regulation. Many of these zinc-finger domains are involved in DNA binding. This study investigated whether the zinc-co-ordinating (Cys)2(His)2 motif found in the three zinc fingers of zif268 could be replaced by a (Cys)4 motif while still preserving DNA recognition. (Cys)2(His)2-to-(Cys)4 mutations were generated in each of the three zinc fingers of zif268 individually, as well as in fingers 1 and 3, and fingers 2 and 3 together. Whereas finger 1 and finger 3 tolerate the switch, such an alteration in finger 2 renders the polypeptide incapable of DNA recognition. The protein-DNA interaction was examined in greater detail by using a methylation-interference assay. The mutant polypeptides containing the (Cys)4 motif in fingers 1 or 3 recognize DNA in a manner identical to the wild-type protein, suggesting that the (Cys)4 motif appears to give rise to a properly folded finger. Additional results indicate that a zif268 variant containing a (Cys)2(His)(Ala) arrangement in finger 1 is also capable of DNA recognition in a manner identical to the wild-type polypeptide. This appears to be the first time that such alterations, in the context of an intact DNA-binding domain, have still allowed for specific DNA recognition. Taken together, the work presented here enhances our understanding of the relationship between metal ligation and DNA-binding by zinc fingers.

Characterization of the glnK-amtB operon of Azotobacter vinelandii

To determine whether in Azotobacter vinelandii the PII protein influences the regulation of nif gene expression in response to fluxes in the ammonium supply, the gene encoding PII was isolated and characterized. Its deduced translation product was highly similar to PII proteins from other organisms, with the greatest degree of relatedness being exhibited to the Escherichia coli glnK gene product. A gene designated amtB was found downstream of and was contranscribed with glnK as in E. coli. The AmtB protein is similar to functionally characterized ammonium transport proteins from a few other eukaryotes and one other prokaryote. glnK and amtB comprise an operon. Attempts to isolate a stable glnK mutant strain were unsuccessful, suggesting that glnK, like glnA, is an essential gene in A. vinelandii. amtB mutants were isolated, and although growth on limiting amounts of ammonium was similar in the mutant and wild-type strains, the mutants were unable to transport [14C]methylammonium.

Serum inhibins A and B fall differentially as FSH rises in perimenopausal women

BACKGROUND

Serum FSH levels rise with increasing age in normal women, particularly as they enter the menopausal transition and progress to the postmenopausal state. The contributions of decreasing levels of inhibin-A (INH-A) and inhibin-B (INH-B) to this rise are presently unclear, as there are no reports of dimeric INH levels in relation to menopausal status. The present study was undertaken in order to provide preliminary data on relationships amongst the dimeric inhibins, oestradiol (E2) and FSH in normal subjects of defined menopausal status.

METHODS

Single serum samples were obtained between cycle days 3 and 8 in regularly cycling women, or at random in those with irregular cycles or amenorrhoea, in 110 women, aged 48-59 years, in the third year of a prospective longitudinal study of the menopausal transition, 'The Melbourne Women's Mid-Life Health Project'. Samples were assayed for FSH, E2, INH-A, INH-B and immunoreactive inhibin (IR-INH) and results were analysed following logarithmic transformation. Undetectable values were assigned the limit of sensitivity of the respective assays. The relationships between hormones were evaluated as a function of menopausal stage. The latter was assigned as Stage 1, premenopausal (no reported change in menstrual cycle pattern), Stage 2, early peri-menopausal (reported change in menstrual cycle frequency in the preceding year with a bleed in the preceding 3 months), Stage 3, late peri-menopausal (no menses in the preceding 3-11 months) and Stage 4, postmenopausal (no menses in the preceding 12 months).

RESULTS

The hormone concentrations in premenopausal subjects (geometric means, FSH 13.5 IU/l, E2 306 pmol/l, IR-INH 217 U/l, INH-A 96 ng/l, and INH-B 48 ng/l) were used as reference points for the other stages of menopausal status. Early peri-menopausal subjects had significantly lower levels of IR-INH (147 U/l) and INH-B (13.5 ng/l) in the presence of a small, statistically nonsignificant rise in FSH (to 21.4 U/l) and no significant change in E2 or INH-A. In late peri-menopausal subjects, IR-INH fell to 76 U/l, INH-A fell to 4.2 ng/l, whilst INH-B was not significantly different at 14 ng/l. FSH had risen significantly to 72.21 U/l. Oestradiol also fell significantly to 89 pmol/l. In the postmenopausal subjects there were no further significant changes in the peptide hormones or FSH, but E2 fell further to 41 pmol/l. There was a significant (P < 0.05) inverse correlation between FSH and E2 (R = -0.78), FSH and IR-INH (R = -0.66), FSH and INH-A (R = -0.53), FSH and INH-B (R = -0.29) while IR-INH and either INH-A or INH-B were positively correlated (R = +0.57 and +0.35, respectively). The data are consistent with negative feedback roles for both dimeric inhibins and E2 as contributors to the regulation of FSH secretion as menopausal status changes.

CONCLUSIONS

The major significant endocrine event in women in the early peri-menopausal phase of the menopausal transition is a substantial fall in the circulating levels of inhibin-B with no significant change in inhibin-A or oestradiol. Progression to late peri-menopausal status is accompanied by a marked fall in inhibin-A and oestradiol and a rise in FSH without further change in inhibin-B. Inhibin-B, a marker of follicle number, is a significant factor in the endocrinology of the menopausal transition.

Suppression of tumorigenic and metastatic potentials of human melanoma cell lines by mutated (143 Val-Ala) p53

Metastatic melanoma, compared with other cancers, appears to be unusual because of its low frequency of p53 mutations and prevalence of wild-type p53 protein in advanced malignancy. Here, we examined the effects of wild-type and mutated p53 (143 Val-Ala) on tumorigenic and metastatic potential of two human melanoma cell lines. The cell line UISO-MEL-4 contains wild-type p53 and is tumorigenic, whereas UISO-MEL-6 lacks p53 and produces lung and liver metastasis upon s.c. injection into athymic mice. Our study showed that UISO-MEL-4 stably transfected with wild-type p53 cDNA driven by cytomegalovirus promoter-enhancer sequences expressed high levels of p53 and p21 and formed s.c. tumours in vivo. Mutated p53 (143 Val-Ala) expression, on the other hand, inhibited tumour growth in 50% of cases and produced significantly slower growing non-metastatic tumours. Reduced tumour growth involved necrotic as well as apoptotic cell death. Inhibition of tumour growth was abrogated by the addition of Matrigel (15 mg ml(-1)). With UISO-MEL-6 cells, stably transfected with mutant p53, tumour growth was delayed and metastasis was inhibited. In soft agar colony formation assay, both wild-type and mutant p53 transfectants reduced anchorage-independent colony formation in vitro. These data suggest that mutated (143 Val-Ala) p53, which retains DNA binding and some of the transactivation functions of the wild-type p53 protein, suppresses tumorigenic and metastatic potentials of human melanoma cell lines in vivo.

Systemic lupus erythematosus in Denmark: clinical and epidemiological characterization of a county-based cohort

A population based cohort of patients with systemic lupus erythematosus (SLE) was recruited from a for epidemiological purposes representative Danish region. Patients were ascertained from 4 different sources with a high degree of completeness as estimated by using capture-recapture analysis. The diagnosis was verified by means of case records, patient interviews, and clinical examinations. Patients were classified according to the 1982 revised ACR criteria as Definite SLE (D-SLE) fulfilling > or = 4 criteria and Incomplete SLE (I-SLE) with < 4 criteria. As of January 1, 1995, the point prevalences of D-SLE and I-SLE were 21.7 and 5.2 per 100000 respectively. The cohort comprised 98% white Europeans. The annual incidence of D-SLE increased from 1.0/100,000 to 3.6/100,000 during the study period 1980-94. D-SLE patients had clinical profiles comparable to other Western European study populations. The I-SLE subclass had milder disease manifested by lower criterial load and absence of cerebral and kidney involvement. Tissue and organ damage expressed as SLICC-score increased in the order of live I-SLE, live D-SLE, and deceased patients.

Identification of non-heme diiron proteins that catalyze triple bond and epoxy group formation

Acetylenic bonds are present in more than 600 naturally occurring compounds. Plant enzymes that catalyze the formation of the Delta12 acetylenic bond in 9-octadecen-12-ynoic acid and the Delta12 epoxy group in 12,13-epoxy-9-octadecenoic acid were characterized, and two genes, similar in sequence, were cloned. When these complementary DNAs were expressed in Arabidopsis thaliana, the content of acetylenic or epoxidated fatty acids in the seeds increased from 0 to 25 or 15 percent, respectively. Both enzymes have characteristics similar to the membrane proteins containing non-heme iron that have histidine-rich motifs.

Current concepts of shoulder arthroplasty

Shoulder arthroplasty is an accepted treatment for certain proximal humerus fractures and for glenohumeral arthritis. The indications for shoulder arthroplasty are fairly well defined and the outcomes are predictable and highly successful. However, it is a technically demanding surgical procedure, with which few orthopaedic surgeons gain much experience. Most of the currently available implant systems are modifications of the original unconstrained components that were introduced by Neer. Current issues of controversy include implant modularity, glenohumeral mismatch, implant fixation, and the role of glenoid replacement in outcome.

A comparison of disease and gene frequencies of inborn errors of metabolism among different ethnic groups in the West Midlands, UK

OBJECTIVE

To assess birth and gene frequencies of specific autosomal recessively inborn errors of metabolism (IEM) within different ethnic groups.

DESIGN

Retrospective study in a regional centre for investigation and treatment of IEM.

SUBJECTS

All children born within the West Midlands NHS Region, UK, during the decade immediately preceding the 1991 National Census.

METHODS

Birth frequencies for individual IEM were calculated separately for the main ethnic groups in the West Midlands using data from the West Midlands Neonatal Screening Programme, the regional register of IEM patients, and population frequencies from the National Census. Gene frequencies were calculated using previously documented observations on parental consanguinity rates and inbreeding coefficients.

RESULTS

The overall incidence of recorded IEM was tenfold higher among Pakistanis compared to white children (1:318 v 1:3760), whereas only one AfroCaribbean child was identified (incidence 1:16 887). Tyrosinaemia type 1, cystinosis, mucopolysaccharidosis type 1, non-ketotic hyperglycinaemia, and hyperchylomicronaemia all occurred more frequently among Pakistanis. An increased gene frequency was only confirmed for tyrosinaemia. The incidence of phenylketonuria was similar in Pakistani and white children (1:14 452 v 1:12 611), but the gene frequency was significantly lower in Pakistanis (1:713 v 1:112). These results illustrate the interplay between gene frequency and parental consanguinity in determining disease frequencies in different populations, and indicate anticipated disease frequencies in the absence of consanguineous marriage. These figures have implications for the organisation of services for management of inborn errors, for genetic counselling, and for the assessment of gene flow in world populations.

Alterations in colonic mucosal vessels in patients with cirrhosis and noncirrhotic portal hypertension

Changes in intestinal mucosal microvasculature as a cause of lower gastrointestinal hemorrhage in patients with portal hypertension have been well documented clinically, but the analogous histomorphological changes have not been well characterized. The goal of this study was to evaluate qualitative and quantitative changes in colonic mucosal vessels in patients with cirrhosis or clinically evident portal hypertension and to correlate these changes with endoscopic and clinical findings. Colon biopsy or resection specimen slides from 46 patients with biopsy-proven cirrhosis (44 patients) or noncirrhotic portal hypertension (two patients) were reviewed. Immunoperoxidase stain for CD34 antigen was used to facilitate visualization of mucosal vessels, and vessel diameter was measured with a micrometer. Patients with inflammatory bowel disease were excluded. Twenty-four normal colon biopsy specimens served as controls. Mucosal vessels were divided into superficial, intermediate, and deep layers. As a group, the cirrhotic patients had a significantly higher mean diameter of vessels in all three layers. Qualitatively, increased numbers of small vessels and prominent branching were noted, especially in the superficial and intermediate layers. Tortuous, thick-walled vessels, suggesting arterialization of venules, were present in some cases. Eleven patients had endoscopic findings suggestive of vascular abnormalities, including erythematous mucosal patches, red macules, and telangiectasias. Eighteen had esophageal varices, and five had portal gastropathy. Nineteen patients had gastrointestinal (GI) bleeding, localized to the lower GI tract in 11. These qualitative and quantitative findings suggest that colonic mucosal vascular lesions are common in portal hypertension and may represent a potential source of clinically significant lower GI hemorrhage in these patients.

The shady side of solar protection

OBJECTIVE

To determine the value of shade in protecting humans from solar ultraviolet (UV) radiation.

DESIGN AND SETTING

Measurement with photometers of protection factors for ultraviolet B radiation (UVB) and for total solar radiation for different types of trees and other structures during the summer months (1995-1997) in south-east Queensland. (The protection ratio is the ratio of the intensity of UVB or total solar radiation in direct sunlight to that in shade.)

RESULTS

For summer sun at midday, the mean (SD) UV protection ratio for the shade of trees (n = 65) was 4.21 (1.36) on a horizontal surface and 1.33 (0.30) on a vertical surface. In contrast, the mean (SD) protection ratio for total solar energy (primarily infrared) was much higher (12.1 [1.4]). Trees common in recreational areas in Australia (eucalypts: UV protection ratio, 3.52 [0.79]; Norfolk Island pines: UV protection ratio, 3.72 [0.98]) offered reduced protection compared with trees with more dense foliage (UV protection ratio, 5.48 [1.44]). Over a whole day, measurement of shade by trees and other structures showed that the UV protection ratio was lower in the morning and afternoon. Shade from awnings, buildings and hats gave similar results to those for trees. Both at midday and over a whole day satisfactory protection (UV protection ratio > 15) was obtained only in shade which eliminated exposure to the sky as well as to direct sunlight; for example, in thickly wooded areas and under low, widely overhanging structures.

CONCLUSIONS

Most forms of shade, while useful, offer people insufficient protection from solar UV. A fair-skinned person sheltering under a tree could suffer sunburn after less than one hour. There is a need for appropriate design of structural shade, use of other solar protection measures in conjunction with shade, and research on behavioural responses to shade.

Comparative pupil dilation using phenylephrine alone or in combination with tropicamide

OBJECTIVE

A prevalence survey of actinic and other eye diseases was conducted in Nambour, Queensland, Australia, in 1992. Pupils were dilated with phenylephrine alone for cataract identification because there were concerns that patient discomfort, due to cycloplegia occurring with the usual dilating agents of tropicamide and phenylephrine, may influence future compliance in an associated intervention study. This validation study was undertaken to measure the possible underestimation of cataract prevalence in this community study, which may have occurred because of inadequate dilation from phenylephrine alone.

DESIGN

The study design was a repeated measures experimental design.

PARTICIPANTS

Forty-seven normal subjects participated in the study. Both eyes were tested.

INTERVENTION

Pupil diameter after dilation with three drops of 10% phenylephrine alone was compared with pupil diameter after dilation with three drops of 10% phenylephrine together with three drops of 1% tropicamide. The two regimens were given to the same subjects 1 week apart. Reversal was attempted with thymoxamine hydrochloride 0.5%.

MAIN OUTCOME MEASURES

Pupil diameter was assessed using a Neitz cataract camera, and accommodation reserve also was measured. Subjects' subjective appreciation of return of ocular function was assessed by a questionnaire. Repeated measures analysis of variance, paired t test, McNemar's test, and Wilcoxon signed rank test were used to analyze outcomes.

RESULTS

Mean maximum pupil size with 10% phenylephrine and 1% tropicamide was significantly larger than pupil size after the use of 10% phenylephrine alone (F1,19 = 18.99, P = 0.0003). However, there was no significant difference between the two dilation regimens when comparing the proportion of subjects who dilated to 6 mm or more (McNemar's X(2)1 = 2.7, P > 0.1). Compared with 10% phenylephrine and 1% tropicamide, pupil diameters were significantly smaller (t46 = 16.77, P = 0.0001), and accommodation reserve greater (t46 = 4.14, P = 0.0001), 40 minutes after reversal with thymoxamine in the group dilated with 10% phenylephrine alone.

CONCLUSION

Pupil dilation with 10% phenylephrine alone, if allowed at least 40 minutes to act, will be as satisfactory for the identification of cataracts in a normal population as 10% phenylephrine and 1% tropicamide and is more acceptable because of reduced problems with glare and accommodation.

Neonatal screening for inborn errors of metabolism: cost, yield and outcome

OBJECTIVES. To systematically review the literature on inborn errors of metabolism, neonatal screening technology and screening programmes in order to analyse the costs and benefits of introducing screening based on tandem mass-spectrometry (tandem MS) for a wide range of disorders of amino acid and organic acid metabolism in the UK. To evaluate screening for cystic fibrosis, Duchenne muscular dystrophy and other disorders which are tested on an individual basis. HOW THE RESEARCH WAS CONDUCTED. Systematic searches were carried out of the literature on inborn errors of metabolism, neonatal screening programmes, tandem MS-based neonatal screening technology, economic evaluations of neonatal screening programmes and psychological aspects of neonatal screening. Background material on the biology of inherited metabolic disease, the basic philosophy, and the history and current status of the UK screening programme was also collected. Relevant papers in the grey literature and recent publications were identified by hand-searching. Each paper was graded. For each disease an aggregate grade for the state of knowledge in six key areas was awarded. Additional data were prospectively collected on activity and costs in UK neonatal screening laboratories, and expert clinical opinion on current treatment modalities and outcomes. These data were used to construct a decision-analysis model of neonatal screening technologies, comparing tandem MS with the existing phenylketonuria screening methods. This model determined the cost per additional case identified and, for each disease, the additional treatment costs per case, and the cost per life-year saved. All costs and benefits were discounted at 6% per annum. One-way sensitivity analysis was performed showing the effect of varying the discount rate, the incidence rate of each disorder, the number of neonates screened and the cost of tandem MS, on the cost per life-year gained. RESEARCH FINDINGS. The UK screening programmes for phenylketonuria and congenital hypothyroidism have largely achieved the expected objectives and are cost-effective. Current concerns are the difficulty of maintaining adequate coverage, perceived organisational weaknesses, and a lack of overview. For many of the organic acid disorders it was necessary to rely on data obtained from clinically-diagnosed cases. Many of these diseases can be treated very effectively and a sensitive screening test was available for most of the diseases. Except for cystic fibrosis, there have been no randomised controlled trials of the overall effectiveness of neonatal screening. Despite the anxiety generated by the screening process, there is strong parental support for screening. The effects of diagnosis through screening on subsequent reproductive behaviour is less clear. Conflicts exist between current concepts and the traditional principles of screening. The availability of effective treatment is not an absolute prerequisite: early diagnosis is of value to the family concerned and, to the extent that is leads to increased use of prenatal diagnosis, may help to reduce the overall burden of disease. Neonatal screening is also of value in diseases which present early but with non-specific symptoms. Indeed, almost all of the diseases considered could merit neonatal screening. The majority of economic evaluations failed to incorporate the health benefits from screening, and therefore failed to address the value of the information which the screening programmes provided to parents. The marginal cost of changing from present technology to tandem MS would be approximately 0.60 pounds per baby at a workload of 100,000 samples a year, and 0.87 pounds at 50,000 samples per year. The ability to screen for a wider range of diseases would lead to the identification of some 20 additional cases per 100,000 infants screened, giving a laboratory cost per additional diagnosis of 3000 pounds at an annual workload of 100,000 babies per year.(ABSTRACT TRUNCATED)

Neonatal screening: current trends and quality control in the United Kingdom

Neonatal screening for phenylketonuria (PKU) and congenital hypothyroidism (CHT) is universal across the UK using heel prick blood collected at 6-14 days of age. Additional programmes for sickle cell disorders, cystic fibrosis, Duchenne muscular dystrophy and galactosaemia are provided in some areas. The number of inherited metabolic disorders (IMDs) has greatly increased since the introduction of PKU screening, and there have been major advances in treatment, e.g. organ transplantation, drug therapy. Recent developments in technology have expanded the possibilities for screening using the heel prick blood specimen, particularly the application of tandem mass spectrometry. There is a case for introducing tandem mass spectrometry, limited to clearly defined diseases where specificity is adequate and there are satisfactory diagnostic tests. Any change in newborn screening to a much broader group of disorders must be carefully introduced and monitored preferably as a pilot study. A key component of a laboratory screening service is quality control. There are well established UK programmes for PKU and CHT. Consideration of the needs for other disorders is now an important priority.

Inhibition of protein synthesis by nitric oxide correlates with cytostatic activity: nitric oxide induces phosphorylation of initiation factor eIF-2 alpha

BACKGROUND

Nitric oxide (NO) is cytostatic for proliferating cells, inhibits microbial growth, and down-regulates the synthesis of specific proteins. Studies were undertaken to determine the mechanism by which NO inhibits total protein synthesis and whether the inhibition correlates with established cytostatic activities of NO.

MATERIALS AND METHODS

In in vitro experiments, various cell types were exposed to NO using either donors or expression of inducible NO synthase (iNOS). The capacity of NO to suppress total protein synthesis, measured by incorporation of 35S-methionine into protein, was correlated with the capacity of NO to suppress cell proliferation, viral replication, or iNOS expression. Phosphorylation of eIF-2 alpha was examined as a possible mechanism for the suppressed protein synthesis by NO.

RESULTS

Both NO donors and expression of the iNOS suppressed total protein synthesis in L929 cells and A2008 human ovarian tumor cells in parallel with decreased cell proliferation. Suppressed protein synthesis was also shown to correlate with decreased vaccinia virus proliferation in murine peritoneal macrophages in an iNOS-dependent manner. Furthermore, iNOS expression in pancreatic islets or RAW264.7 cells almost completely inhibited total protein synthesis, suggesting that nonspecific inhibition of protein synthesis may be the mechanism by which NO inhibited the synthesis of specific proteins such as insulin or iNOS itself. This possibility was confirmed in RAW264.7 cells where the inhibition of total protein synthesis correlated with the decreased iNOS protein. The decrease in protein levels occurred without changes in iNOS mRNA levels, implicating an inhibition of translation. Mechanistic studies revealed that iNOS expression in RAW264.7 cells resulted in the phosphorylation of eIF-2 alpha and inhibition of the 80S ribosomal complex formation.

CONCLUSIONS

These results suggest that NO suppresses protein synthesis by stimulating the phosphorylation of eIF-2 alpha. Furthermore, our observations indicate that nonspecific inhibition of protein synthesis may be a generalized response of cells exposed to high levels of NO and that inhibition of protein synthesis may contribute to many of the described cytostatic actions of NO.

[Insulin-dependent diabetes in the county of Funen 1970-2020. An epidemiological description]

We present an epidemiological model applicable to insulin-dependent diabetes mellitus (IDDM), based on which prevalence rates are estimated from assumed rates of incidence and mortality of diabetes. The model is illustrated by analysing epidemiological data on IDDM in Fyn County, Denmark for the period 1970-1990, with predictions of prevalence rates during 1990-2020. The epidemiological model assumes known prevalence rates as well as incidence rates and mortality at a given point of time. Under assumed rates of incidence and mortality of IDDM and its complications, the prevalence rate is the dependent variable which is estimated as a function of calendar time. We used epidemiological data on IDDM (operationally defined as insulin-treated diabetes with onset before age 30 years), blindness and nephropathy as well as mortality as reported for the years 1973 and 1987 in Fyn County, Denmark. During 1970-1990 the prevalence of IDDM increased steadily, due to increasing incidence and decreasing risk of complications and mortality. The relative prevalence of patients with nephropathy increased whereas that of blind patients decreased considerably. Under specified assumptions regarding the future levels of incidence of disease, complications and of mortality, it is estimated that the prevalence rate of IDDM in the year 2020 will be 45-60% higher than the level in 1990. The relative prevalence of patients with nephropathy will increase further, whereas the relative prevalence of blind patients will remain constant at a low level. We conclude that IDDM will represent an increasing public health problem in Denmark over the next decades, with increasing overall prevalence rates and a rising proportion of patients with nephropathy. The major determinants of this trend are increasing incidence, combined with declining mortality and declining risk of complications. It is recommended that epidemiological modelling techniques be further developed to provide improved data for the planning of the future diabetes care.

History of tropical military service and risk of primary cutaneous melanoma in Queensland men

A population-based case-control study was undertaken to determine whether cutaneous melanoma is associated with past military service in tropical locations. The participants were 150 male residents of southern Queensland aged 50 or over with a first diagnosis of cutaneous melanoma notified to the Queensland Cancer Registry between 1 July 1993 and 30 June 1994; 150 age-matched controls were randomly selected from the Queensland electoral roll. Data were collected from participants using a structured questionnaire. Overall, 82 (55%) cases and 80 (53%) controls reported a period of military service. Of these, 42% of both cases and controls spent part of their military service in tropical locations, with little difference in the distribution of duration of tropical service between the two groups. Compared with those who had no tropical military service, the risk of melanoma among those who had served more than 3 years in the tropics was 0.9 (0.3-2.7). Against a background level of very high risk of melanoma among Queensland men, there was no evidence that tropical military service materially increased the risk.