Subtrochanteric insufficiency fractures associated with bisphosphonate use: 2 case reports and review

Insufficiency fractures are beginning to emerge in case reports of patients on long-term bisphosphonate therapy. The side effects associated with the long-term use of bisphosphonates were once thought to only involve renal and gastrointestinal (GI) toxicity and osteonecrosis of the jaw, but it is becoming clear that the very condition bisphosphonates were meant to treat could be causing another, trading insufficiency fractures for another type of insufficiency fracture. We review the literature concerning this surprising trend in addition to providing 2 case reports and conclude that these fractures do occur, that they can heal uneventfully, and that further research is needed to determine optimum treatment algorithms concerning duration of treatment and to weigh the potential benefits and morbidity of bisphosphonate treatment.

Influences of age, gender, smoking, and family history on autoimmune thyroid disease phenotype

CONTEXT

Both genetic and environmental factors contribute to susceptibility to Graves' disease (GD) and Hashimoto's thyroiditis (HT), as well as disease manifestations.

OBJECTIVE

The objective of the study was to define how endogenous/environmental factors contribute to variation in phenotype.

DESIGN/SETTING

This was a multicenter cohort study. PATIENTS/OUTCOME MEASURES: We prospectively collected clinical/biochemical data as part of the protocol for a United Kingdom DNA collection for GD and HT. We investigated, in 2805 Caucasian subjects, whether age at diagnosis, gender, family history (FH), smoking history, and presence of goiter influenced disease manifestations.

RESULTS

For 2405 subjects with GD, the presence of goiter was independently associated with disease severity (serum free T4 at diagnosis) (P < 0.001). Free T4 (P < 0.05) and current smoking (P < 0.001) were both independent predictors of the presence of ophthalmopathy. Approximately half of those with GD (47.4% of females, 40.0% of males) and HT (n = 400) (56.4% of females, 51.7% of males) reported a FH of thyroid dysfunction. In GD, a FH of hyperthyroidism in any relative was more frequent than hypothyroidism (30.1 vs. 24.4% in affected females, P < 0.001). In HT, a FH of hypothyroidism was more common than hyperthyroidism (42.1 vs. 22.8% in affected females, P < 0.001). For GD (P < 0.001) and HT (P < 0.05), a FH was more common in maternal than paternal relatives. The reporting of a parent with thyroid dysfunction (hyper or hypo) was associated with lower median age at diagnosis of both GD (mother with hyperthyroidism, P < 0.001) and HT (father with hypothyroidism, P < 0.05). In GD and HT, there was an inverse relationship between the number of relatives with thyroid dysfunction and age at diagnosis (P < 0.01).

CONCLUSIONS

Marked associations among age at diagnosis, disease severity, goiter, ophthalmopathy, smoking, and FH provide evidence for interactions between genetic and environmental/endogenous factors; understanding these may allow preventive measures or better tailoring of therapies.

The importance of testing for adrenoleucodystrophy in males with idiopathic Addison's disease

X linked adrenoleucodystrophy (X-ALD) is considered to be a rare cause of Addison's disease, although several small series suggest a high incidence in young Addisonian males. A survey in the south west of England identified 12 male patients diagnosed with Addison's disease in the period 1987-99. In 10 of these (83%) X-ALD was the underlying cause; the other two were of autoimmune aetiology. Five boys had developed Addison's disease subsequent to the diagnosis of X-ALD. Of the remaining five, in three boys the diagnosis of X-ALD was considerably delayed (by six months to two years from that of Addison's disease) and in two it was only made as a result of this survey. We also identified a patient who presented with Addison's disease at the age of 5 years but was only diagnosed as having X-ALD at the age of 34 years; in the interim his diagnosis of adrenomyeloneuropathy had been missed. Our experience highlights the absolute necessity of measuring very long chain fatty acids in all males with idiopathic Addison's disease.

Inflammatory hypophysitis - the spectrum of disease

BACKGROUND

Inflammatory conditions of the pituitary are rare and consequently there are a number of single case reports of this condition but few reports of series. The condition is often divided into lymphocytic and granulomatous hypophysitis and it has been suggested that these two conditions represent the ends of a spectrum of disease.

METHOD

We present our experience with 14 cases of this condition, correlating the presenting symptoms with the neuroradiology, surgical findings and subsequent histology.

FINDINGS

The subjects (11 female 3 male) ranged in age from 13 to 64 years. Final histopathological diagnoses included 5 cases of lymphocytic hypophysitis, 4 cases of Rathke's pouch cyst with granulomatous response, 2 cases of granulomatous hypophysitis and 1 case with an inflammatory process that did not fit the current classification. Two subjects did not undergo surgery. Headache was a presenting feature in 11 of 14 cases and fever in 3 of 14 cases. Length of symptoms prior to presentation varied from acute onset to 9 years. One case of lymphocytic hypophysitis was associated with pregnancy. Evidence of hypopituitarism was present in 9 of 10 subjects assessed preoperatively. Preoperative radiology showed three patterns of disease: A cystic appearance was common with low signal content on MRI T1 weighting with an enhancing ring and a thickened enhancing stalk (5 patients). 4 patients showed a solid enhancing mass. A third group (2 patients) showed cysts with high signal content on T1 weighting - both of these were Rathke's cysts on histology.

INTERPRETATION

Overall there were no striking features in the clinical presentation to distinguish pituitary inflammation from pituitary adenoma. The prognosis was generally good.

General medicine in the UK - back stage or centre stage?

Internal medicine, in the UK as well as in the rest of Europe, is in a state of flux. The service has evolved so that the management of acute medical emergencies increasingly dominates the practice of internal medicine, with most outpatient work being dealt with by specialists. As a result, much of the activity of consultant physicians is focused on the delivery of care rather than on the training aspects of internal medicine. Nevertheless, all medical specialists in the UK do pass through a rigorous period of internal medicine during their early training, and there is now increasing emphasis on ensuring that these skills are maintained by practising physicians.

An exception to the rule: ectopic ACTH production from functional neuroendocrine tissue in an ovarian dermoid cyst

Ectopic ACTH production accounts for 15% of Cushing's syndrome presentations and is characterized by the presence of an excess of ACTH precursors. However in the case presented here ectopic ACTH production was from functional pituitary tissue within an ovarian dermoid cyst. Endocrine investigations showed that the problem behaved more like pituitary-dependent Cushing's disease and this is discussed. Furthermore, this case is one of familial dermoid cysts, another unusual phenomenon.

Trans-sphenoidal encephalocele in association with Dandy-Walker complex and cardiovascular anomalies

We present a case of trans-sphenoidal encephalomeningocele in association with a posterior cranial fossa malformation which fulfils the criteria for the Dandy-Walker complex [1]. Congenital cardiovascular defects were also present. An abnormality of neural crest development may be responsible for the combined occurrence of these anomalies.

Improving quality measures in the emergency services

A large and continuing increase in medical emergency admissions has coincided with a reduction in hospital beds, putting the acute medical services under great pressure. Increasing specialization among physicians creates a conflict between the need to cover acute unselected medical emergencies and the pressure to offer specialist care. The shortage of trained nursing staff and changes in the training of junior doctors and the fall in their working hours contribute to the changing role of the consultant physician. The organization of the acute medical service is of paramount importance and requires multi-disciplinary teamwork on an admissions unit with full support services. Excellent bed management is essential. There must be guidelines for all the common medical emergencies and all units must undertake specific audits of the acute medical service. Continuing professional development (CPD) and continuing medical education (CME) should reflect the workload of the physician; that is, it must include time specifically focused on acute medicine and general (internal) medicine, as well as the specialty interest.

Radiation-induced carcinogenesis: studies using human epithelial cell lines

It has proved difficult to develop suitable models to study radiation-induced carcinogenesis by using human epithelial cells. However, immortalised human epithelial cell lines have proved useful. Unirradiated cells from the human keratinocyte cell line (HPV-G) and the human embryonic lung cell line (L132) were found to be tumourigenic in T-cell-deficient mice; thus, they are not suitable for transformation studies. Human urothelial cell lines (SV-HUC-1, NT11, BC16) and the human thyroid epithelial cell line (HTori-3) were nontumourigenic. The urothelial cell lines were refractory to radiation-induced carcinogenesis, and only one small tumour was observed in 57 mice that received irradiated cells. Whereas tumours were not produced following irradiation of these urothelial cells, changes in anchorage-independent growth were observed after a single dose of 8 Gy gamma-irradiation but not after 2 or 4 Gy. Irradiation of the human thyroid epithelial cell line (HTori-3) in vitro resulted in tumour formation. Passaging of the cells in vitro before injection did not seem to be critical. Some of the cell lines derived from the primary thyroid tumours exhibited p53 mutations in exons 5, 6, 7, and 8, as detected by single-stranded conformational polymorphism (SSCP) analysis. Thus, the human thyroid epithelial cell line (HTori-3) looks promising as a model for investigating the molecular events in radiation-induced carcinogenesis.

Computer-assisted venous occlusion plethysmography in the diagnosis of acute deep venous thrombosis

Suspicion of deep venous thrombosis (DVT) is a common reason for acute medical admission. The clinical diagnosis is difficult, and thus significant numbers are investigated and found to be normal. Provision of 24-h radiology is costly, and there may be a delay in investigation. We assessed computer-assisted venous occlusion plethysmography as a screening test for DVT, compared with standard radiology. The test has the advantage of being performed on the ward and if reliable would significantly reduce the number of radiological investigations required. We enrolled 215 consecutive patients presenting with the possible diagnosis of DVT, of whom 144 had technically adequate plethysmography results. Plethysmography had a sensitivity of 96% (95%CI 88-99%) and a negative predictive value of 97% (95%CI 91-99%). Patients excluded because of technically inadequate results were older (by a mean 7 years, p=0. 003). Computer-assisted venous occlusion plethysmography is a non-invasive method of rapidly screening for DVT which may be safely used as an initial screening test. The test is less useful in older patients, or patients unable to keep still for a period of 2 min.

What should we do? Papillary thyroid carcinoma in a lymph node but normal thyroid tissue--how should we proceed?

Papillary cell carcinoma of the thyroid is a relatively indolent disease, usually presenting as an asymptomatic mass in the thyroid gland that is either noted by the patient or diagnosed at routine clinical examination. Although the prognosis is generally good there are a number of controversies in the management of this condition. The significance of age at presentation, size of the tumour and the presence of lymph node metastasis are still disputed. We present the unusual case of a woman found to have papillary cell thyroid carcinoma within a lymph node during a cosmetic thyroid lobectomy. The thyroid tissue removed was not found to contain tumour. We describe the evidence behind the decision to proceed to total thyroidectomy and the finding of a tiny focus of papillary cell thyroid carcinoma within the contralateral lobe.

The development of Graves' disease and the CTLA-4 gene on chromosome 2q33

Case-control studies suggest that the CTLA-4 gene may be a susceptibility locus for Graves' disease. The previously reported A/G polymorphism at position 49 in exon 1 of the CTLA-4 gene was, therefore, investigated in a case-control (n = 743) and family-based (n = 179) dataset of white Caucasian subjects with Graves' disease. The relationship between CTLA-4 genotype and severity of thyroid dysfunction at diagnosis was also investigated. An increase in frequency of the G (alanine) allele was seen in Graves' patients compared with control subjects (42% vs. 31.5%, respectively; corrected P<0.0002; odds ratio = 1.58), and a significant difference in the distribution of GG, GA, and AA genotypes was observed between the groups (chi2 = 21.7; corrected P<0.00003). Increased transmission of the G allele was seen from heterozygous parents to affected offspring compared to unaffected offspring (chi2 = 5.7; P = 0.025). Circulating free T4 concentrations at diagnosis were significantly associated with CTLA-4 genotype (F = 3.26; P = 0.04). These results support the hypothesis that CTLA-4 may play a role in regulating self-tolerance by the immune system and in the pathogenesis of autoimmune disorders such as Graves' disease.

Secondary prevention of coronary heart disease in primary care: a healthy heart initiative

We assessed the effectiveness of secondary prevention of coronary heart disease (CHD) in primary care, in a cross-sectional study of 1015 patients aged < 75 years with documented CHD. Patients records were examined for documentation of CHD risk factors; 722 patients then attended education sessions where blood pressure and cholesterol were measured, a supervised questionnaire detailing modifiable risk factors was completed, and advice on lifestyle modification was given. Management of risk factors was generally poor, and was worse in women. Approximately 20% of subjects remained hypertensive, with half of these receiving anti-hypertensive medication. Examining the primary care records, serum cholesterol was documented in 17.5% of men and 26.5% of women. Of the 722 subjects who had cholesterol measured, 30% of men and 25% of women had cholesterol < 5.2 mmol/l. Mean cholesterol was significantly higher in the women (6.1 mmol/l vs. 5.6 mmol/l, p = 0.001). Lifestyle risk management was also poor, with significant numbers smoking and drinking more than recommended. Women were more overweight than men (mean BMI 27.9 kg/m2 vs. 26.9 kg/m2, p = 0.006). Aspirin was being taken by 56% of patients.

Experience with transdermal testosterone replacement therapy for hypogonadal men

BACKGROUND

None of the existing options for long-term testosterone replacement therapy (TRT) for hypogonadal men are ideal. Depot replacement at frequent intervals and implants are effective but invasive and inconvenient for the patient. Oral therapy results in poor hormone levels. Both are associated with undesirable metabolic changes. A transdermal formulation therefore represents a potential therapeutic advance for testosterone replacement.

OBJECTIVE

To carry out a clinical audit of the acceptability and efficacy as a treatment for hypogonadism of the first transdermal testosterone therapy available in the UK (Andropatch, SmithKline Beecham) compared with existing androgen replacement options.

PATIENTS AND MEASUREMENTS

Serum testosterone and questionnaire data on treatment efficacy, side-effects, therapy preference, sexual dysfunction and partner's attitudes to therapy were obtained from 50 hypogonadal men prescribed long-term testosterone replacement.

RESULTS

Eighty per cent of the men returned analysable questionnaires. Eighty-four per cent experienced adverse effects with transdermal therapy, most commonly dermatological problems; 22% of the sample elected to continue with transdermal therapy, 72% returned to depot and 5% returned to oral therapy. The reservoir patches were judged to be too large, uncomfortable, visually obtrusive and noisy. Testosterone levels were comparable to those obtained with depot replacement with the added advantage of a more physiological pharmacokinetic profile. Men taking oral preparations were consistently under-replaced.

CONCLUSIONS

Adverse events were substantially higher than reported from clinical trials but in keeping with the spectrum of yellow card reports received by the Committee on Safety of Medicines. The pharmacokinetic advantages are thus largely outweighed by low patient acceptability. In its present form transdermal therapy remains an expensive option for those who cannot tolerate depot testosterone replacement.

Linkage disequilibrium between the human leukocyte antigen class II region of the major histocompatibility complex and Graves' disease: replication using a population case control and family-based study

Early case control studies found association of the DRB1 allele, DR3, with Graves' disease (GD). Recent reports, claim the DQA1 allele, DQA1*0501, to be the primary susceptibility determinant within the human leukocyte antigen (HLA) class II region. We typed 228 GD patients, 364 controls, and 98 families (parents, GD, and unaffected sibling) at the DRB1, DQB1, and DQA1 loci. The case control study showed an increased frequency in GD, compared to controls, of DRB1*0304 (47% vs. 24%; pc < 1.4 x 10(-5)), DQB1*02 (58% vs. 46%; pc < 0.035), DQB1*0301/4 (42% vs. 28%; pc < 3.5 x 10(-3)) and DQA1*0501 (67%, vs. 39%; pc < 7 x 10(-6)). The DRB1*0304-DQB1*02-DQA1*0501 haplotype was increased in GD (47%) vs. controls (24%; pc < 1.8 x 10(-5); odds ratio = 2.72). No independent association of these alleles was observed. Preferential transmission of DRB1*0304-DQB1*02-DQA1*0501 from parents heterozygous for the haplotype to GD siblings (72%) was seen in the families (chi2 = 11.95; 1 d.f.; P = 0.0005). Lack of preferential transmission to unaffected siblings (53%; chi2 = 0.19; 1 d.f.; P = NS) excluded segregation distortion. These results show that linkage disequilibrium between GD and the HLA class II region is due to the extended haplotype DRB1*0304-DQB1*02-DQA1*0501.

Metronidazole sensitivity testing of Helicobacter pylori: the importance of media

Successful triple-therapy treatment for Helicobacter pylori infection depends upon metronidazole (Mz) susceptibility, and many hospital laboratories routinely screen H. pylori isolates for Mz resistance using disc diffusion methods. We report the importance of culture medium when testing for metronidazole susceptibility. In this laboratory, Mz resistance in strains of H. pylori from patients in our area was found in approximately 80%. In other areas, Mz resistance is found in approximately 30%. This high rate of Mz resistance was not reflected clinically. Added haemin (X factor) and menadione in the culture medium drastically reduced zone size to Mz and also interfered with the minimal inhibitory concentration (MIC) as determined by Etest. When strains of H. pylori were re-tested on media which did not contain X factor or menadione, Mz resistance fell from 80% to 39%, a level similar to that seen in other areas.

Prolactinoma presenting in identical twins with multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type one (MEN 1) is characterized by tumours of the parathyroid glands, pancreatic islet cells and the anterior pituitary and follows an autosomal dominant pattern of inheritance. We report identical twins born to a family known to have the MEN 1 syndrome. The twins were identical until puberty. The first twin underwent puberty normally; the second, however, suffered an early pubertal arrest and was subsequently found to have a prolactinoma. Both were also subsequently shown to have primary hyperparathyroidism. Genetic studies have since confirmed the twins identical for the affected haplotype and show that this is inherited from the father who also has MEN 1. The gene for MEN 1 has now been localized to the long arm of chromosome 11. The current hypothesis is that expression of the syndrome involves two separate genetic mutations. The first mutation is inherited and thus present in all cells but the tumour manifests itself in the endocrine tissue only after a second mutation that represents elimination of the normal allele. In the case described the twins are proven genetically identical. The marked phenotypic difference between the two must, by inference, represent a second somatic mutation and is further supportive evidence of the two-mutation model of tumour expression.

A good wife, but never a mother

Prolactinomas are the commonest pituitary tumour. They are more frequent in women and account for up to 15% of patients with amenorrhoea (through secondary gonadotrophin suppression). Here we present two patients with previously unrecognized giant prolactinomas, one of whom is probably unique in having radiological evidence of progression from micro to macro prolactinoma in the absence of treatment. Both were being considered for hormone replacement therapy. These tumours are known to be oestrogen sensitive and potentially life threatening. Both had been investigated for amenorrhoea prior to the availability of prolactin assays; no other cause had been found. Amenorrhoeic patients investigated prior to the early 1970s should be reviewed with this in mind. Patients with untreated microprolactinomas should probably be monitored indefinitely.

Immunogold localization of GyrA and GyrB proteins in Escherichia coli

Immunogold preparations of Escherichia coli, using anti-GyrA and anti-GyrB antibodies to the subunits of DNA gyrase, showed clear labelling with both secondary antibody and protein A-gold conjugates. Both proteins were located mainly in the cytoplasm, with typically less than 10% in the nucleoid. This partitioning of gyrase proteins between nucleoid and cytoplasm was nonrandom and was consistently observed for a range of different cell preparations. Total gold particle counts were highly variable but suggested levels of at least 1000-3000 molecules per cell for both GyrA and GyrB. Sequential treatment with both anti-GyrA and anti-GyrB monoclonal antibodies resulted in simultaneous labelling of both proteins and revealed no clear association between the two groups of molecules. Treatment of cells with chloramphenicol caused marked changes in nucleoid conformation, but no reduction in cytoplasmic labelling of gyrase proteins. On the assumption that gyrase complexes within the nucleoid are not differentially masked from the monoclonal antibodies, the results obtained in this study suggest that most of the gyrase proteins are not associated with either central nucleoid DNA or cytoplasmic loops of peripheral single-stranded DNA, but are distributed randomly throughout the cytoplasm.

A patient with monosomy 7 and polyuria

Diabetes insipidus (DI) is a rare complication of leukaemia. An association between monosomy 7 and DI in leukaemias has been proposed. We present a case of Ph1-positive CML who developed polyuria at the time of lymphoid blast transformation associated with loss of chromosome 7. Biochemical results were not diagnostic of DI and a therapeutic trial of DDAVP was unsuccessful. Post-mortem showed a peripituitary and renal leukaemic infiltrate and although DI is a possibility, the cause of his polyuria remains unresolved.

Insulin autoantibodies in Graves' disease--before and after carbimazole therapy

Insulin autoantibodies (IAA) are well documented in patients with insulin-dependent diabetes (IDDM) prior to the administration of insulin and in patients with reactive hypoglycaemia--the insulin autoimmune syndrome (IAS). It has been suggested that IAA can be induced by the administration of drugs containing sulphydryl groups, such as carbimazole, and they have been frequently described in Graves' disease. An alternative explanation is the clustering of autoantibodies in autoimmune disease. We studied 39 patients (37 females, two males, age range 14 to 61 years; mean 33.8 years) with proven Graves' disease and no previous treatment with carbimazole. Fifteen of the 39 patients had a family history of other autoimmune diseases. IAA and thyroid autoantibodies were assayed at diagnosis and monthly thereafter while on treatment with carbimazole, for up to 6 months. IAA were measured using a direct-binding solid-phase ELISA and specificity was confirmed by absorption studies using insulin covalently coupled to Sepharose beads. At diagnosis 33 of the 39 patients (85%) were positive for thyroid microsomal antibodies, 13 (33%) were positive for thyroglobulin antibodies, and 4 (10%) were positive for IAA. All IAA-positive patients had microsomal antibodies at diagnosis, and two had thyroglobulin antibodies in addition. After 4 months on carbimazole, the frequency of thyroid microsomal autoantibodies was unchanged (83%), while that of anti-thyroglobulin antibodies had fallen (8.6%). All four IAA-positive patients remained positive, and studies of binding to human, porcine and bovine insulin demonstrated that one serum, initially human insulin specific, later became cross-reactive with all three. We conclude that low titres of IAA are found in Graves' disease, and are associated with the presence of autoimmunity rather than the carbimazole. Symptomatic hypoglycaemia, however, is rare in Caucasian patients.

Delayed disappearance of human compared to porcine insulin in a patient with the insulin autoimmune syndrome

The insulin autoimmune syndrome is characterised by high titres of autoantibody to insulin, a high circulating concentration of total insulin and later, reactive hypoglycaemia. We have studied a patient with this syndrome whose insulin autoantibody bound exclusively human insulin. This permitted us to investigate the disappearance of bound (human) and unbound (porcine) insulin in the same patient, using i.v. injections of 0.075 U/g of each insulin on separate days. The peak plasma free insulin concentration following porcine insulin was four times greater than that following the same dose of human insulin. The plasma disappearance half-time of porcine insulin following injection was 11 min compared with 32 min following human insulin injection, and the area beneath the disappearance curve of free insulin during the 120 min of sampling was greater for porcine insulin by a factor of 3.15. The nadir in plasma glucose occurred at 45 min following porcine insulin and at 90 min following human insulin injection. The restoration of basal glucose concentration was correspondingly slower following human insulin, but the absolute fall in glucose achieved was no different. There was no evidence of insulin resistance. Insulin autoantibodies can seriously disturb the kinetics and effect of free insulin.

Insulin autoantibodies and insulin assay

Insulin antibodies are known to interfere with the radioimmunoassay of insulin. We tested intravenous glucose tolerance on 25 insulin autoantibody-positive (IAA+) patients and 25 IAA- controls, who were matched for sex, age, and body mass index, to establish if IAA could also interfere with insulin assay. Insulin content was measured in untreated serum, serum precipitated with polyethylene glycol (PEG, free insulin), and serum extracted with acid and precipitated with PEG (total insulin). The mean untreated first-phase insulin response (I1 + 3) for IAA+ patients was 172 +/- 67.3 mU/L, significantly higher than the mean control value of 108 +/- 47.5 (P less than .001). After PEG precipitation, mean I1 + 3 in the patient group fell significantly to 105 +/- 48.4 mU/L (P less than .001), but the control value was unchanged (104 +/- 45.5). The mean percentage fall after PEG precipitation was 36.9% (patients) and 2.9% (controls) (t = 8.3, P less than .001). There was a strong correlation between the IAA titer and the interference in the insulin assay (r = .81). After total insulin extraction of IAA samples, there was a significant fall in mean I1 + 3 to 134 +/- 55.4 mU/L (P less than .001), but the control value was unchanged. IAA can significantly falsify insulin measurement, and care must be taken in the interpretation of insulin-release tests when IAA is present.

Insulin autoantibody polymorphisms with greater discrimination for diabetes in humans

Insulin autoantibodies, like islet cell antibodies, are found not only in the sera of newly diagnosed Type 1 (insulin-dependent) diabetic patients and their relatives, but also in patients with other autoimmunities who do not develop diabetes. Insulin autoantibodies are oligo/monoclonal and frequently binding-site restricted. As determinant selection is genetically determined, we questioned whether certain polymorphisms of insulin autoantibodies, identified by their binding site on the insulin molecule, could better discriminate for Type 1 diabetes, which is also HLA determined. First, we raised monoclonal antibodies to human insulin by classic fusion methods in order to determine the range of antibody polymorphism, and identified five distinct types by their binding profiles to a panel of insulin variants, using an enzyme-linked immunosorbent assay. Two of these polymorphisms, type A and type B, were subsequently found in insulin autoantibody positive human sera using the same panel of insulin variants, and successfully distinguished diabetes-related from diabetes-unrelated individuals. Thus, the type B polymorphism was responsible for binding in 60% of 41 insulin autoantibody positive individuals with polyautoimmune disease but no personal or family history of diabetes (diabetes unrelated), but in only 2% of a group which comprised 17 newly-diagnosed insulin autoantibody positive Type 1 diabetic patients, 19 insulin autoantibody positive discordant twins of Type 1 diabetes and six insulin autoantibody positive healthy siblings of Type 1 diabetic patients (diabetes related) (p less than 0.01). Isolation of the type A polymorphism alone reduced the proportion of false negatives in the insulin autoantibody test for diabetes relatedness from 49% to 20% without diminishing its specificity.(ABSTRACT TRUNCATED AT 250 WORDS)

On the relationship between islet cell antibodies and insulin autoantibodies in patients at risk from insulin dependent diabetes

The frequencies of islet cell antibodies (ICA) and insulin autoantibodies (IAA) were studied in three clinically well defined groups, using an aprotinin sensitised indirect immunofluorescence assay for ICA and a direct binding solid ELISA for IAA, and the association of these two serological markers for insulin dependent diabetes analysed. Frequency of ICA was 10.7% in siblings of diabetics, 15.5% in discordant identical twins and 65.9% in newly diagnosed diabetic patients. Frequency of IAA was 7.1% in siblings, 46.7% in discordant twins and 38.6% in newly diagnosed diabetic patients. No correlation was demonstrated between the two autoantibodies in the siblings. In the newly diagnosed diabetic patients there were sera positive or negative for both, but 22 (50%) of the sera showed dissociation between the two antibodies. The studies of twins showed that IAA and ICA fluctuated independently with time, and demonstrate the inappropriateness of seeking such an association in cross-sectional surveys. An association could not be demonstrated in this group even if data from multiple samples taken at different points in time were pooled, scoring an individual as positive if at any time their sera had been positive for the corresponding antibody. Thus our data showed no correlation between ICA and IAA in any of the groups studied.

Treatment of diabetic gastroparesis with oral domperidone

Three patients with severe diabetic gastroparesis unresponsive to metoclopramide were found to have markedly prolonged gastric half-emptying times (t1/2) using a radionuclide-labelled test meal. They all showed symptomatic improvement and normal t1/2 within one week of taking oral domperidone 10 mg q.d.s. Oral domperidone may have a role in the treatment of severe diabetic gastroparesis particularly in metoclopramide-resistant cases.

Value of insulin autoantibodies as serum markers for insulin-dependent diabetes mellitus

Insulin autoantibodies (IAA) were studied in newly diagnosed insulin-dependent diabetics before the start of insulin treatment and in unaffected identical twins of insulin-dependent diabetics. In 15 of the 40 (38%) diabetics and 27 of the 58 (47%) twins IAA levels exceeded those of 100 controls. Frequency of IAA in unaffected twins was not related to duration of diabetes in their affected twin. In 11 unaffected twins, IAA levels differed in two samples taken 1-12 years apart; IAA were detected at least once in all twins and in one on both occasions. IAA in the twins were not related to the presence of islet-cell antibodies or to HLA-DR 3 or 4. As the unaffected twins of longstanding diabetics are unlikely to develop diabetes, these observations suggest that IAA do not always presage diabetes and are probably not a consequence of the disease; they may reflect an inherited autoimmune tendency to diabetes.

Abnormal insulin secretion in carcinoma of the pancreas: response to glucagon stimulation

In 34 patients suspected of having pancreatic cancer glucose homeostasis and insulin secretion in response to intravenous glucagon (1 mg) were studied prospectively. Twelve patients had pancreatic cancer at laparotomy and the remainder were designated a control group. Responses were also measured in 12 healthy volunteers. There was no significant difference in the rise of blood glucose between the groups after glucagon. The mean plasma insulin concentrations rose rapidly in both groups after glucagon but were significantly lower in the pancreatic cancer group. In patients with obstructive jaundice the plasma insulin response was a better discriminator of pancreatic cancer. Abnormal pancreatic beta-cell function is detectable in patients with pancreatic carcinoma before any change in glucose homeostasis, particularly in patients with obstructive jaundice. The glucagon stimulation test may be useful in the earlier diagnosis of pancreatic carcinoma before the development of clinically overt diabetes mellitus.

Xenografts of human bladder cancer in immune-deprived mice

Human bladder cancer from cystoscopic biopsies and from established cell lines was transplanted into mice that were immune suppressed by thymectomy plus sequential treatment with 1-beta-D-arabinofuranosylcytosine and whole-body irradiation. Each of four established human bladder cancer cell lines generated transplantable tumors in these mice, and some of the mice developed pulmonary metastases. Eight of 33 cystoscopically obtained biopsies of transitional cell carcinoma and one from a metastatic site led to xenografts that grew progressively, and some of these have been transplanted and/or have generated cell lines in vitro. Xenografts grew after a lag period of 0 to 32 weeks and had doubling times of 9 to 30 days. All of those examined histologically were consistent with transitional cell carcinoma, but some of the xenografts became more or less well differentiated in first and subsequent passages. The immune-deprived mouse is an alternative host to the nude mouse for generation of human tumor xenografts and may be a useful model for study of biological properties and therapeutic response of human bladder cancer.