Small area variation in the incidence of childhood insulin-dependent diabetes mellitus in Yorkshire, UK: links with overcrowding and population density

BACKGROUND

The incidence of insulin-dependent diabetes mellitus (IDDM) incidence varies between and within countries. The origins of this variation are disputed, but they involve both genetic and non-genetic influences. To explore the role of environmental factors in the aetiology of IDDM we have examined the incidence in small geographical areas and related it to variables derived from national censuses.

METHODS

This is an ecological analysis of incidence data from a register of children with IDDM covering the counties of West Yorkshire, North Yorkshire and Humberside in the north of England. All children aged < or = 16, diagnosed with IDDM between 1978 and 1990 were eligible for inclusion. Spatial variation in incidence between electoral wards was investigated using Poisson regression, in relation to socioeconomic status, population density, urban-rural status and measures of geographical isolation. Ward child populations varied in size from 84 to 7197 (mean = 1545).

RESULTS

Rates were significantly lower in wards of high population density and with many overcrowded houses. The rate ratio for areas in the upper half of the childhood density distribution was 0.88 (95% confidence interval (CI): 0.78-0.99) and for the two upper tertiles of household overcrowding the rate ratios were 0.84 (95% CI: 0.74-0.95) and 0.68 (95% CI: 0.58-0.79) respectively.

CONCLUSIONS

The incidence of childhood IDDM was associated with environmental factors including population density and overcrowded homes. A possible inference from these data is that patterns of infection are involved in the occurrence of IDDM. Analytical epidemiological studies will be needed to investigate these ideas further.

Hypertelorism and hypospadias associated with a de novo apparently balanced translocation between 8q22.3-23 and 20p13

A de novo apparently balanced translocation involving chromosomes 8 and 20 was found in a 14-year-old boy with minor anomalies, mild skeletal abnormalities and ambiguous external genitalia including perineoscrotal hypospadias, rudimentary fused labioscrotal folds, bilateral cryptorchidism, and small penis. The karyotype was 46,XY, t(8;20)(q22.3-23;p13). No signs of other conditions known to be associated with structural anomalies of either chromosome 8 or 20 were present and incomplete masculinisation of the external genitalia appears to be the main component of the phenotype. Clinical and biological studies showed apparently normal testicular function in utero and after birth. Examinations excluded 5 alpha-reductase deficiency or a block in any enzymatic steps of testosterone, glucocorticoid and mineralocorticoid biosynthesis. Coding sequences of the sex-determining gene (SRY) and androgen receptor gene (AR) were found to be identical to those of a normal male excluding their role in the cause of the present condition. Since several other reports describe the association of hypospadias and hypertelorism with deletions or translocations involving 8q, we suggest that a locus necessary for male sex differentiation is located at distal 8q.

Dose responses for neostigmine and edrophonium as antagonists of mivacurium in adults and children

BACKGROUND

Reversal of neuromuscular blockade induced with pancuronium, d-tubocurarine, or doxacurium is achieved using smaller doses of neostigmine in adults than in children. Also, pancuronium- and doxacurium-induced blockade is reversed with smaller doses of edrophonium in children than in adults. The purpose of this study was to compare the spontaneous and neostigmine- and edrophonium-assisted recovery of mivacurium-induced neuromuscular block in adults and children.

METHODS

Fifty-four adults, aged 40.1 +/- 10.9 yr, and 54 children, aged 4.9 +/- 0.7 yr, physical status ASA 1-2, were studied during propofol/fentanyl/nitrous oxide anesthesia. A Datex relaxograph was used to monitor the electromyographic response of the adductor pollicis to train-of-four stimulation of the ulnar nerve every 10 s. After induction of anesthesia, 0.2 mg x kg(-1) intravenous mivacurium was administered followed by an infusion to maintain 90-95% T1 block. At the end of surgery, one of four doses of neostigmine (5, 10, 20, and 50 micrograms x kg(-1)) or edrophonium (100, 200, 400, and 1,000 micrograms x kg(-1)) or placebo was given, by random allocation, when T1 had recovered to 10%. Values of T1 and train-of-four were measured for 10 min.

RESULTS

Spontaneous recovery proceeded more rapidly in children than in adults. At 10 min, T1 had recovered to 97 +/- 2% (SD) in children compared with 69 +/- 11% in adults and train-of-four to 84 +/- 5% versus 30 +/- 13% (P<0.0001). In children, 10 min after reversal, recovery of T1 and train-of-four was not different from control after edrophonium and was enhanced only by the larger doses of neostigmine. In adults, recovery was accelerated by both edrophonium and neostigmine. Five minutes after reversal, recovery was improved by either drug in adults and in children.

CONCLUSIONS

Spontaneous recovery from mivacurium- induced neuromuscular block is more rapid in children than in adults. Ten minutes after attempted reversal, recovery is accelerated by edrophonium and usually by neostigmine in adults but not in children. Thus, when reversal is required, edrophonium may be preferred to neostigmine.

Patient and carer satisfaction in geriatric day hospitals

Our objective was to assess the satisfaction of patients who attend geriatric day hospitals, and of their carers. We used a convenience sample survey of 92 patients (mean age 77) and 94 carers of patients attending three geriatric day hospitals in Nottingham, England. Patients were interviewed and carers were contacted by post. Questionnaires were derived from a regional strategy document for the evaluation of day hospital services: 81/92 (88%) patients always liked coming to the day hospital and 77/91 (85%) felt that their attendance was always worthwhile; 85/89 (96%) of the carers felt that the patient had improved; 74/81 (91%) of carers felt that they needed the break from caring afforded by the day hospital attendance and 74/79 (94%) of carers felt that they personally had benefited from it. There was thus a high level of satisfaction with the day hospital service among attenders. The role of the day hospital in supporting carers is greatly appreciated.

Prolonged PR interval is a risk factor for bradycardia during spinal anesthesia

BACKGROUND AND OBJECTIVES

Bradycardia occurs during 9%-13% of spinal anesthetics and may lead to cardiac arrest. Several risk factors for the development of bradycardia have been identified, but the risk conferred by presence of abnormalities detected on preoperative electrocardiogram (ECG) has not been examined. The authors undertook the study to correlate abnormal ECG findings with the incidence of bradycardia.

METHODS

The data-base was previously collected from 952 patients undergoing spinal anesthesia. Patient records were reviewed and 537 had ECGs performed within 6 months of surgery. Intraoperative bradycardia was defined as a heart rate < 50 bpm (plus > 10% decrease from baseline). Abnormalities recorded from the ECG were prolonged PR interval (PR > 0.2 sec), atrial-ventricular conduction abnormalities, evidence of chamber hypertrophy, ischemia, and infarction. The findings were compared with incidence of bradycardia using contingency tables. Significant correlations were then evaluated with logistic regression. Significance was defined as P < .05.

RESULTS

The incidence of bradycardia in this population was 12%. Patients with a prolonged PR interval had an increased incidence of bradycardia (25%, P = .01). Other ECG abnormalities did not correlate with increased incidence of bradycardia. Duration of PR interval did correlate significantly (P = .001) but poorly (r2 = 0.014) with baseline heart rate. However, logistic regression demonstrated that prolonged PR interval was a significant and independent predictor for bradycardia (odds ratio = 3.2, P = .01).

CONCLUSIONS

Risk factors previously identified for the development of bradycardia during spinal anesthesia include: baseline heart rate < 60 bpm, ASA physical status 1 versus 3 or 4, use of beta-blocking drugs, sensory block height > or = T5, and age < 50. The results demonstrate that prolonged PR interval on the preoperative ECG is another significant and independent predictor for bradycardia.

The epidemiology of diabetes mellitus in the United Kingdom: the Yorkshire Regional Childhood Diabetes Register

A register of the incidence of Type 1 (insulin-dependent) diabetes mellitus in the Yorkshire region of the United Kingdom has been completed. A total of 1,490 subjects aged between 0 and 16 years were identified from 1978 to 1990, giving an incidence of 13.7 per 100,000 (ages 0-14) or 13.6 per 100,000 (ages 0-16), comparable to other recent studies in the United Kingdom. An age-period-cohort analysis shows evidence for a modest drift effect of 1.75% per year (95% confidence interval 0.28 to 3.25%). There is a marked epidemic pattern with peaks at 4-year intervals. The age-incidence curve is similar to that reported elsewhere, having peaks in early childhood and puberty. Girls have an earlier pubertal peak than boys. There is substantial seasonal variation in incidence confined to those over 5 years of age. Ascertainment is believed to be very complete, and is estimated to be 97.6% (95% confidence interval 97.2% to 98.1%).

HTLV-II infection in Florida Indians

A significantly increased prevalence of antibodies to human T-cell leukemia virus (HTLV) has been described in several native American populations in the United States and Latin America. Initial virologic studies indicate that HTLV-II is the predominant virus responsible for this antibody pattern. We obtained blood samples from 106 Seminole Indians living on four reservations in Southern Florida. Seropositivity to HTLV-I/II was found in 14 (13.2%) of these individuals. Polymerase chain reaction (PCR) documented HTLV-II and the absence of HTLV-I in 7 of the 9 donors available for follow-up testing of white blood cells. Evaluation of various risk factors excluded blood transfusion or intravenous drug use as an important contributing factor to the HTLV-II seroprevalence rate. These studies support the hypothesis that HTLV-II is endemic in many native American tribes in the Western hemisphere.

Prescribing and dispensing of insulin: margins for error?

To investigate recent anecdotal reports of incorrect insulin dispensing, we compared retail pharmacists' and doctors' understanding of commonly used insulin brands. Eighty pharmacists, 29 general practitioners (GPs), and 31 junior hospital doctors were interviewed and completed a questionnaire concerning the duration of action and formulation of 17 insulins. Views on dispensing of alternative insulins were sought from the pharmacists. Fifteen insulin pairs in two columns, 'insulin prescribed' and 'dispense instead', were presented and pharmacists and doctors asked if substitution was appropriate. Mixtard, Penmix and Actrapid were the best understood insulins, Insulatard, Humulin Zn and Protaphane the worst. Both GPs (p = 0.014) and hospital doctors (p < 0.001) scored better than pharmacists. No pharmacist stated that they would routinely dispense alternative insulin, 27 out of 80 not even in an emergency, though 37 were prepared to do so in such a situation after checking, usually with a doctor or in the relevant literature. Sixteen pharmacists, 24 GPs, and all 31 hospital doctors completed the section on insulin pairs but accuracy at identifying appropriate substitutions was poor. These findings coupled with confusing insulin nomenclature may lead to dangerous dispensing errors.

Incidence and risk factors for side effects of spinal anesthesia

We prospectively studied 952 patients to identify the incidence of hypotension (systolic blood pressure less than 90 mmHg), bradycardia (heart rate less than 50 beats/min), nausea, vomiting, and dysrhythmia during spinal anesthesia. Historical, clinical, and physiologic data were correlated with the incidence of these side effects by univariate and multivariate analysis. Hypotension developed in 314 patients (33%), bradycardia in 125 (13%), nausea in 175 (18%), vomiting in 65 (7%), and dysrhythmia in 20 (2%). Variables conferring increased odds of developing hypotension include peak block height greater than or equal to T5 (odds ratio 3.8, P less than 0.001), age greater than or equal to 40 yr (2.5, P less than 0.001), baseline systolic blood pressure less than 120 mmHg (2.4, P less than 0.001), combination of spinal and general anesthesia (1.9, P = 0.01), spinal puncture at or above the L2-L3 interspace (1.8, P less than 0.001), and addition of phenylephrine to the local anesthetic (1.6, P = 0.02). Variables conferring increased odds of developing bradycardia include a baseline heart rate less than 60 beats/min (odds ratio 4.9, P less than 0.001), ASA physical status classification of 1 versus 3 or 4 (3.5, P less than 0.001), current therapy with beta-adrenergic blocking drugs (2.9, P less than 0.001), and peak block height greater than or equal to T5 (1.7, P = 0.02). Variables conferring increased odds of developing nausea or vomiting include addition of phenylephrine or epinephrine to the local anesthetic (3.0-6.3, P less than or equal to 0.003), peak block height greater than or equal to T5 (odds ratio 3.9, P less than 0.001), use of procaine (2.6-4.4, P less than or equal to 0.003), baseline heart rate greater than or equal to 60 beats/min (2.3, P = 0.03), history of carsickness (2.0, P = 0.01), and development of hypotension during spinal anesthesia (1.7, P = 0.009). Our results indicate that the incidence of side effects during spinal anesthesia may be reduced by 1) minimizing peak block height; 2) using plain solutions of local anesthetics; 3) performing the spinal puncture at or below the L3-L4 interspace; and 4) avoiding the use of procaine in the subarachnoid space.

Evidence for an environmental effect in the aetiology of insulin dependent diabetes in a transmigratory population

OBJECTIVE

To examine whether children of families moving from an area of low incidence of childhood diabetes to one which is higher show a corresponding rise in disease incidence.

DESIGN

Disease incidence study over 12 years.

SETTING

Bradford District Metropolitan Council area.

SUBJECTS

All subjects aged 0-16 years resident within the study area.

MAIN OUTCOME MEASURES

The incidences of childhood diabetes in Asian and non-Asian families.

RESULTS

The incidence of diabetes in Asian children increased from 3.1/100,000 per year in 1978-81 to 11.7/100,000 per year in 1988-90 (chi 2 for trend = 4.95, df = 1, p = 0.026) whereas that for other children remained constant at 10.5/100,000 per year. Over the entire study period rates were lower in Asian females (4.9/100,000 per year) than in Asian males (8.8/100,000 per year) whereas the reverse was true for other children (males 9.2/100,000 per year; females 12.0/100,000 per year) (test for common odds ratio: chi 2 = 3.81, df = 1, p = 0.052).

CONCLUSIONS

Offspring of this transmigratory population had a rising incidence of childhood diabetes which was approaching that of the indigenous population. The data provide strong evidence for an environmental effect in the aetiology of insulin dependent diabetes.

The concept of hope revisited for nursing

The development of nursing knowledge and interventions involve understanding human responses and needs. The human response of hope was identified as a concept in need of further clarification. The purpose of this paper was to review definitions and contextual usage of the word 'hope' from the literature and answer the conceptual question 'What is hope?' Literature from theology, philosophy, psychology and nursing was reviewed for contextual usage of the word 'hope'. In the literature, hope was viewed as part of human development, a process, a theory and a source of meaning in life. In addition, antecedents, attributes and outcomes of hope were identified from the literature that contributed to a clearer understanding of the concept.

Normal expression of thymidine kinase and O6-methylguanine-DNA methyltransferase in cultured fibroblasts from individuals with hereditary galactokinase deficiency

Expression of the enzymes galactokinase, thymidine kinase, and O6-methylguanine-DNA methyltransferase is occasionally coordinately regulated in human cell lines. We have measured the activities of these three enzymes in extracts of fibroblasts from individuals with hereditary galactokinase deficiency. These cells do not express measurable galactokinase activity. The levels of O6-methylguanine-DNA methyltransferase were in the normal range in cells from three galactokinase-deficient individuals. The activity of thymidine kinase in the affected cells was in the normal range for two of the three individuals. The reduced thymidine kinase activity in the third individual reflected the extremely poor growth of the cells in culture. Immortalization of one galactokinase-deficient cell line resulted in loss of O6-methylguanine-DNA methyltransferase activity, but the galactokinase and thymidine kinase levels remained unchanged. The data indicate that the loss of galactokinase activity in these individuals is the consequence of an alteration of gene expression which does not involve coordinate silencing with the thymidine kinase and methyltransferase loci.

Regulation of O6-methylguanine-DNA methyltransferase expression in the Burkitt's lymphoma cell line Raji

We have investigated the expression of the DNA-repair enzyme O6-methylguanine-DNA methyltransferase in the Burkitt's lymphoma cell line Raji. An existing mutant Raji cell line which lacks thymidine kinase activity had previously been shown to be Mex- and to no longer express O6-methylguanine-DNA methyltransferase. We report here that in addition to the methyltransferase and thymidine kinase, a third enzyme with an unrelated function, galactokinase, is also not expressed in Raji cells. The control of thymidine kinase expression is post-transcriptional and it is possible that galactokinase and methyltransferase can share a common post-transcriptional regulation with thymidine kinase.

Intralesional interferon gamma treatment for keloids and hypertrophic scars

Keloids and hypertrophic scars are characterized by excessive collagen formation. Interferon gamma is a lymphokine that can down-regulate collagen synthesis in vitro and in vivo and, therefore, has potential therapeutic benefit in the management of abnormal scars. Intralesional scar injections of interferon gamma were performed to determine the tolerance toxicity and to obtain preliminary evidence for the efficacy of this treatment in the management of hypertropic and keloid lesions. All scars decreased in linear dimensions and flattened out. Five of 10 scars studied decreased at least 50% in linear dimensions. Interferon gamma can safely be administered intralesionally once per week up to a dosage of 0.05 mg for 10 weeks with no serious toxic effects. The commonest reported side effect was a mild headache.

Coregulation of the human O6-methylguanine-DNA methyltransferase with two unrelated genes that are closely linked

The loss of expression of the enzyme O6-methylguanine-DNA methyltransferase (the Mex- phenotype), which often results from cellular transformation, confers hypersensitivity to alkylating agents. We have observed two unrelated examples in which human cell lines have undergone a spontaneous alteration in their Mex phenotype during propagation in vitro. The change was reversible and was not the result of mutation. In both cases a loss of methyltransferase expression was accompanied by a simultaneous loss of expression of two metabolically unrelated enzymes: thymidine kinase and galactokinase. "Reversion" to methyltransferase expression was accompanied by simultaneous reexpression of both kinase activities. A third example of this coordinate gene regulation was seen with the Burkitt's lymphoma cell line Raji which expresses methyltransferase, thymidine kinase, and galactokinase at high levels. A thymidine kinase- Raji cell line derived by bromodeoxyuridine mutagenesis that is also Mex- was found to be galactokinase-. It appears that methyltransferase expression may in some instances be coordinately regulated with the tk and glk loci which are closely linked on human chromosome 17.

Selective binding to DNA base pair mismatches by proteins from human cells

Using the technique of delayed oligonucleotide migration through polyacrylamide gels, we have demonstrated that cell-free extracts of the human Burkitt's lymphoma cell line Raji contain proteins which can recognize and bind to mismatched single base pairs in short fragments of DNA. One of these binding proteins resembles an activity previously reported in HeLa cells (Jiricny, J., Hughes, M., Corman, N., and Rudkin, B. B. (1988) Proc. Natl. Acad. Sci. U. S. A. 85, 8860-8864) and recognizes DNA containing G.T mismatches. Extracts of Raji cells contain an additional activity which recognizes A.C, T.C, or T.T mismatches in DNA. This second binding protein can be distinguished from the G.T binding activity by its size, substrate specificity, and its fractionation properties. In addition to Raji cells, the new mismatch binding protein is present in extracts of human lymphoblastoid cell lines from a normal individual and a xeroderma pigmentosum patient as well as the SV40-transformed human fibroblast cell line MRC5V1. It seems likely that this novel activity is involved in a broad specificity DNA repair pathway for the correction of single base mismatches in human cells.

The contribution of O6-methylguanine and methylphosphotriesters to the cytotoxicity of alkylating agents in mammalian cells

A modified Escherichia coli ada+ gene which encodes methyltransferase active on O6-methylguanine, but not methylphosphotriester residues in DNA has been introduced by transfection into Chinese hamster ovary cells. Expression of the altered Ada protein in these cells conferred resistance to methylating agents. However, in two independently derived cell lines, the relation between enzyme activity and the degree of protection was not quantitative. The molecular nature of the Ada protein fragment produced differed between the two cell lines. In addition, cell lines exhibiting increased resistance to N-methyl-N'-nitro-N-nitrosoguanidine have been derived from a cell line expressing the Ada protein methylphosphotriester repair function. The resistant cell lines expressed elevated levels of methylphosphotriester repair protein. However, this enhanced DNA repair activity was not responsible for the observed resistance.

Factors influencing acquired subgottic stenosis in infants

A prospective study of factors that might contribute to the development of acquired subglottic stenosis was undertaken in newborn infants with endotracheal tubes in place for 7 days or more. Duration of intubation, the number of endotracheal tubes inserted, the duration of mechanical ventilation, the presence of post-extubation stridor, and the size of the endotracheal tube in relation to gestational age significantly correlated with the development of subglottic stenosis. Patients at risk for significant subglottic stenosis were those with post-extubation stridor and those with tubes in place for 25 days or longer. On the basis of these findings, it is recommended that endotracheal tubes be chosen such that the ratio of nominal tube size divided by the patient's gestational age in weeks is less than 0.1.

Visits by elementary school children to the school nurse

Various factors seem to influence health seeking and illness behavior in childhood, among which are early socialization, modeling behavior in adults, the labeling of illness and psychological distress. The characteristics of a group of elementary school children who visited the nurse's office were observed and descriptive data were obtained on 551 students during a six-month period. Correlation analysis of the data was made. The conclusion of the study supported the following ideas: 1) health seeking and illness behavior was a learned process; 2) there was no differences noted in the frequency of visitation by boys or girls; and 3) recurrent health problems contributed to the frequency of visitation. The role of the school nurse in assessing potential physical and or psychological problems was affirmed.

Reconstruction of the eyelid using a myocutaneous island flap

Traditionally, skin flaps have been based upon a contiguous skin pedicle. Recently the concept has re-emerged that the important blood supply frequently lies subjacent to the flap. A temporally based island flap composed of skin and orbicularis muscle, nourished only by its subjacent pedicle, has been successfully used in the reconstruction of 91 eyelid defects.