Abnormal splicing of hepatocyte nuclear factor 1 alpha in maturity-onset diabetes of the young.

AIMS/HYPOTHESIS: Mutations in the HNF-1 alpha gene result in maturity-onset diabetes of the young (MODY); an early-onset, dominantly inherited form of diabetes caused by pancreatic beta-cell dysfunction. Splice site mutations represent approximately 10% of reported HNF-1 alpha mutations. No studies to date have investigated the effect of splice site mutations on mRNA processing because the tissues with abundant HNF-1alpha expression (liver, pancreas, kidney and gut) are not easily accessible for analysis. This study aimed to define the pathogenic mechanism in three novel splice site mutations by analysing illegitimate transcripts. METHODS: To assess the consequence of potential HNF-1 alpha splice site mutations we developed a nested reverse transcriptase PCR (RT-PCR) assay for the amplification of illegitimate HNF-1 alpha transcripts in Epstein Barr virus transformed lymphoblastoid cell lines. RESULTS: Sequencing the illegitimate HNF-1 alpha transcripts showed that the splice donor site mutation IVS8nt+1G>A leads to complete skipping of exon 8, the splice acceptor site mutation IVS4nt-2A>G causes skipping of exon 5 with the recruitment of a cryptic splice acceptor site within intron 5 and the cryptic splice acceptor site mutation (IVS7nt-6G>A) resulted in the skipping of exon 7. All three changes are predicted to result in premature termination of the HNF-1alpha protein, providing further evidence for their role as pathogenic mutations. CONCLUSION/INTERPRETATION: We conclude that the sequencing of illegitimate transcripts from lymphoblastoid cell lines is helpful in the assessment of intronic variation in HNF-1 alpha that could alter splicing. This analysis of the mRNA is required to define mutational mechanisms and confirm pathogenic status.

Improvements in the provision of hospital diabetes services in an English region 1988-98.

AIMS: To investigate the changes in provision of hospital-based services for patients with diabetes in an English region over a 10-year period. METHODS: Questionnaires were completed by lead clinicians in hospitals in the Northern region of England in 1988 and repeated in 1998. Information was sought on diabetes service provision including the staff and their working practices. Data are presented to demonstrate changes during the 10 years. RESULTS: During a 10-year period the number of consultants providing specialized diabetes services increased from 16 to 25 (to become one per 126 240 population). Their outpatient sessions changed from 34 to 55.5 per week, with a decrease in nonspecialists providing diabetes services. Reductions occurred in registrar numbers providing sessions from 23 to 15 and senior house officers from 16 to 14. Increases occurred in other health care professionals: diabetes specialist nurses from 19 to 30.3 whole time equivalents (WTEs); dieticians from 16 to 32.3 WTEs and chiropodists from 8 to 23 WTEs. The numbers of specialized clinics and units providing services from diabetes care centres increased. Improved facilities in clinics and access to laboratory tests were available to all units. Diabetes registers came into use in 12 of 16 units, but there have been difficulties in providing funding. 'Out-of-hours' advice has moved towards advising their patients to see their general practitioners or the accident and emergency department of the hospitals. CONCLUSIONS: The number of diabetes professional staff and the provision of specialized diabetes services have increased during a 10-year period in the Northern region of England. However, they still fall far short of recommended staffing levels and services are far from comprehensive in most districts.

Conditioning of hydrogel lenses by a multipurpose solution containing an ocular lubricant.

PURPOSE: The addition of the ocular lubricant hydroxypropyl methylcellulose (HPMC) to a multipurpose contact lens solution conditions the hydrogel lens surface. This investigation reports the clinical benefits to contact lens wearers and the improved physical properties of the solution with HPMC added. METHODS: One-hundred forty-seven subjects wearing a variety of hydrogel lenses used a multipurpose solution with and without addition of HPMC and were assessed for product comfort and preference. In the laboratory, conditioning by HPMC was demonstrated in fluid coating, dynamic contact angle, uptake of fluid on hydrogel lenses, and release of HPMC from lenses after soaking. RESULTS: Lens wearers reported the multipurpose solution with HPMC more comfortable, including measures relating to maintaining lens moisture over time. The multipurpose solution with HPMC produced a thicker and longer-lasting layer of fluid on hydrogel lenses and other plastics than other multipurpose solutions. HPMC was found to adsorb to both group 1 and 4 lens materials and release gradually, with detectable amounts releasing from the lens beyond 12 hours. CONCLUSIONS: The conditioning properties of the multipurpose solution with HPMC produce improved wetting of lenses and enhanced lens wearing comfort. Binding of HPMC to the lens surface and subsequent time-release is the probable mechanism for these benefits.

HOPE for patients with Type 2 diabetes: an application of the findings of the MICRO-HOPE substudy in a British hospital diabetes clinic.

AIMS: The MICRO-HOPE substudy demonstrated that when ramipril treatment was added to people with Type 2 diabetes and additional cardiovascular risk factors cardiovascular events were reduced by 25% in 4.5 years. We wished to determine the proportion of people with Type 2 diabetes and additional cardiovascular risk factors registered with a hospital diabetes service. METHODS: Non-proteinuric people (n = 1370) with Type 2 diabetes identified on our diabetes register were subject to analysis. Anticipated reductions in cardiovascular events due to ramipril treatment were based on reductions observed in the MICRO-HOPE substudy. RESULTS: Non-proteinuric people (n = 1075 (78%)) with Type 2 diabetes had at least one additional cardiovascular risk factor. Twenty-nine percent were already taking an angiotensin-converting enzyme inhibitor. The remaining 764 patients were similar to ramipril-treated participants in the MICRO-HOPE substudy. Treatment with ramipril for 4.5 years would be anticipated to reduce cardiovascular deaths by 26, revascularization procedures by 19 and admissions for myocardial infarction and stroke by 18 and 26, respectively. CONCLUSIONS: Of non-proteinuric people with Type 2 diabetes, 78% have additional cardiovascular risk factors. Only a small proportion currently receive treatment with an angiotensin-converting enzyme inhibitor. The incidence of cardiovascular events could be reduced if more patients were treated with ramipril and other cardiovascular risk factors were addressed.

A new variant of Carney's triad: phaeochromocytoma and chondrosarcoma.

A 61 year old hypertensive woman presented in 1986 with a right scapular chondrosarcoma. She developed type 1 diabetes mellitus in 1991 and suffered a stroke in 1991. Chest radiography showed pulmonary metastases in 1997. Further radiological staging detected a right sided phaeochromocytoma, which was subsequently removed in 1998. Before this, repeated urine estimations of vanillylmandelic acid had been normal. Her diabetes was cured by adrenalectomy. It is believed that the combination of phaeochromocytoma and extrapulmonary chondrosarcoma represents a new variant of Carney's triad.

Excess mortality in a population with diabetes and the impact of material deprivation: longitudinal, population based study.

OBJECTIVES: To establish the age and sex specific mortality for people with diabetes in comparison with local and national background populations; to investigate the relationship between mortality and material deprivation in an unselected population with diabetes. DESIGN: Longitudinal study, using a population based district diabetes register. SETTING: South Tees, United Kingdom. PARTICIPANTS: All people known to have diabetes living in Middlesbrough and Redcar and Cleveland local authorities on 1 January 1994. MAIN OUTCOME MEASURE: Death, from any cause, between 1 January 1994 and 31 December 1999. RESULTS: Over the six years of the study 1205 (24.9%) of 4842 participants died. All cause standardised mortality ratios for type 1 diabetes were 641 (95% confidence interval 406 to 962) in women and 294 (200 to 418) in men, and those for type 2 diabetes were 160 (147 to 174) in women and 141 (130 to 152) in men. Cause specific standardised mortality ratios were increased for ischaemic heart disease, cerebrovascular disease, and renal disease; no reductions in mortality from other causes were seen. The risk of premature death increased significantly with increasing material deprivation (P<0.001). CONCLUSIONS: Diabetes is associated with excess mortality, even in an area with high background death rates from cardiovascular disease. This excess mortality is evident in all age groups, most pronounced in young people with type 1 diabetes, and exacerbated by material deprivation. Aggressive approaches to the management of cardiovascular risk factors could reduce the excess mortality in people with diabetes.

Evidence for a Graves' disease susceptibility locus at chromosome Xp11 in a United Kingdom population.

Graves' disease (GD), which has a strong female preponderance (female/male ratio, >5:1), is inherited as a complex genetic trait. Loci for GD have started to be defined using genome-wide approaches for genetic linkage. To date, 3 loci have been confirmed in at least 2 cohorts of GD patients, the strongest effect being at the cytotoxic T lymphocyte antigen-4 (CTLA-4) locus on chromosome 2q33 in our population. Two other loci for GD have recently been proposed, but not confirmed, on chromosomes Xq21 (GD3) and 14q31 (GD1). We studied a cohort of 75 sibling pairs with GD from the United Kingdom for linkage to 12 markers over a 83-cM region of the X chromosome and for 8 markers over a 36-cM region of 14q31-q33. A peak multipoint nonparametric linkage score of 2.21 (P = 0.014) was found at marker DXS8083 on Xp11, which increased to a nonparametric linkage score of 3.18 (P = 0.001) in data that had been conditioned for allele sharing at the CTLA-4 locus under an epistatic model. There was no evidence to support linkage of GD to Xq21.33-q22 (GD3) or at the 14q31-q33 (GD1) region in our population. A locus with a moderate contribution to GD susceptibility (lambda(s) = 1.4) is likely to exist in the Xp11 region, but we are unable to confirm that the GD1 or the GD3 regions contain major susceptibility loci in our United Kingdom GD population.

Evidence for a new Graves disease susceptibility locus at chromosome 18q21.

Graves disease (GD) is a common autoimmune thyroid disorder that is inherited as a complex multigenic trait. By using a single microsatellite marker at each locus, we screened the type 1 diabetes loci IDDM4, IDDM5, IDDM6, IDDM8, and IDDM10 and the fucosyltransferase-2 locus for linkage in sib pairs with GD. This showed a two-point nonparametric linkage (NPL) score of 1.57 (P=.06) at the IDDM6 marker D18S41, but NPL scores were <1.0 at the other five loci. Thus, the investigation of the IDDM6 locus was extended by genotyping 11 microsatellite markers spanning 48 cM across chromosome 18q12-q22 in 81 sib pairs affected with autoimmune thyroid disease (AITD). Multipoint analysis, designating all AITD sib pairs as affected, showed a peak NPL score of 3.46 (P=.0003), at the marker D18S487. Designation of only GD cases as affected (74 sib pairs) showed a peak NPL score of 3.09 (P=.001). Linkage to this region has been demonstrated in type 1 diabetes (IDDM6), rheumatoid arthritis, and systemic lupus erythematosus, which suggests that this locus may have a role in several forms of autoimmunity.

Association analysis of the cytotoxic T lymphocyte antigen-4 (CTLA-4) and autoimmune regulator-1 (AIRE-1) genes in sporadic autoimmune Addison's disease.

Although autoimmune Addison's disease (AAD) may occur as a component of the monogenic autoimmune polyendocrinopathy type 1 syndrome (APS1), it is most commonly found as an isolated disorder or associated with the autoimmune polyendocrinopathy type 2 syndrome (APS2). It is likely that sporadic (non-APS1) AAD is inherited as a complex trait; however, apart from the major histocompatibility complex, the susceptibility genes remain unknown. We have examined polymorphisms at two non-major histocompatibility complex candidate susceptibility loci in sporadic (non-APS1) AAD: the cytotoxic T lymphocyte antigen-4 (CTLA-4) gene and the autoimmune regulator (AIRE-1) gene. DNA samples from AAD subjects (n = 90) and local controls (n = 144 for CTLA-4; n = 576 for AIRE-1) were analyzed for the CTLA-4A/G polymorphism in exon 1 of the CTLA-4 gene and for the common mutant AIRE-1 allele (964de113) in United Kingdom subjects with APS1, by using the restriction enzymes Bst7II and BsrBI, respectively. There was an association of the G allele at CTLA-4A/G in AAD subjects (P = 0.008 vs. controls), which was stronger in subjects with AAD as a component of APS2 than in subjects with isolated AAD. In contrast, the mutant AIRE-1 964del13 allele was carried in one each of the 576 (0.2%) control subjects and the 90 (1.1%) AAD subjects as a heterozygote (P = 0.254, not significant), suggesting that this common AIRE-1 gene abnormality does not have a major role in sporadic (non-APS1) AAD.

The cytotoxic T lymphocyte antigen-4 is a major Graves' disease locus.

Graves' disease (GD) is an autoimmune thyroid disorder that is inherited as a complex trait. We have genotyped 77 affected sib-pairs with autoimmune thyroid disease for eight polymorphic markers spanning the cytotoxic T lymphocyte antigen-4 ( CTLA-4 ) region of chromosome 2q31-q33, and for five markers spanning the major histocompatibility complex ( MHC ) region of chromosome 6p21. Non-parametric analysis showed linkage of GD to the CTLA-4 region with a peak non-parametric linkage (NPL) score of 3.43 ( P = 0.0004) at the marker D2S117. The proportion of affected full-sibs sharing zero alleles (z0) reached a minimum of 0.113 close to D2S117, giving a locus-specific lambdas for this region of 2.2. Families with brother-sister sib-pairs showed a peak NPL of 3.46 ( P = 0.0003, lambdas > 10) at D2S117, compared with 2.00 ( P = 0.02, lambdas = 1.9) in the families with only affected females, suggesting a stronger influence in families with affected males. Association between GD and the G allele of the Thr17Ala polymorphism within the CTLA-4 gene ( CTLA4A/G ) was observed using unaffected sib controls ( P = 0.005). Lesser evidence for linkage was found at the MHC locus, with a peak NPL score of 1.95 ( P = 0.026), between the markers D6S273 and TNFalpha. We demonstrate that the CTLA-4 locus (lambdas = 2.2) and the MHC locus (lambdas = 1.6) together confer approximately 50% of the inherited susceptibility to GD disease in our population.

Rosai-Dorfman disease presenting as a pituitary tumour.

A 45-year-old woman had pyrexia, headaches, collapse and hyponatraemia. Intracerebral abscess, bacterial meningitis and subarachnoid haemorrhage were excluded. She was given intravenous antibiotics and gradually recovered. One month later she was readmitted with diplopia, headache and vomiting. Serum sodium was low (107 mmol/l) and a diagnosis of inappropriate ADH secretion was made. MRI scan showed a suprasellar tumour arising from the posterior pituitary gland. A skin rash gradually faded. Serum cortisol, prolactin, gonadotrophins and thyroid hormone levels were low. A pituitary tumour was removed trans-sphenoidally, she had external pituitary radiotherapy, and replacement hydrocortisone and thyroxine. She was well for 12 months when she developed progressive weakness and numbness of both legs. Examination suggested spinal cord compression at the level of T2 where MRI scanning showed an intradural enhancing mass. This spinal tumour was removed and her neurological symptoms disappeared. Nine months after this she developed facial pain and nasal obstruction. CT scan showed tumour growth into the sphenoid sinus and nasal cavities. A right Cauldwell-Luc operation was done and residual tumour in the nasal passages was treated by fractionated external radiotherapy and Prednisolone. Histological examination of the specimens from pituitary, spinal mass, and nasal sinuses showed Rosai-Dorfman disease, a rare entity characterized by histiocytic proliferation, emperipolesis (lymphophagocytosis) and lymphadenopathy. Aged 48 she developed cranial diabetes insipidus. Although Rosai-Dorfman syndrome is rare, it is being reported with increasing frequency, and should be borne in mind as a possible cause of a pituitary tumour.

Spontaneous partial expectoration of an endobronchial carcinoid.

Typical pulmonary carcinoid tumors often present as proximal endobronchial masses discovered during the evaluation of cough and/or hemoptysis. We present a case of a carcinoid tumor that presented with spontaneous partial expectoration. A review of the literature revealed 16 cases of expectoration of fragments from various primary and metastatic tumors. Our case appears to be the first report of the expectoration of a carcinoid tumor.

Sexual dimorphism in 11 beta hydroxysteroid dehydrogenase activity and its relation to fat distribution and insulin sensitivity; a study in hypopituitary subjects.

OBJECTIVE: Sexual dimorphism of 11 beta hydroxysteroid dehydrogenase activity (11 beta HSD) as measured by the urinary 11-OH/11-oxo cortisol metabolite ratio has been documented in healthy subjects. Since body composition, fat distribution and insulin sensitivity vary between the sexes we have investigated whether these factors may account for the observed difference. Studies were performed in ACTH deficient hypopituitary subjects to eliminate the effect of feedback modulation of cortisol secretion. DESIGN AND PATIENTS: 44 hypopituitary patients, (m:f, 32:12), median age 51 years, median weight 86 kg, on hydrocortisone and other replacement therapy as appropriate were studied. MEASUREMENT: Urine 11-OH/11-oxo cortisol metabolites and serum and urine cortisone (E) and cortisol (F) were measured in relation to total cortisol metabolites and cortisol binding globulin; fat distribution was assessed by Dual Energy X-ray absorptiometry (DXA), and insulin sensitivity by homeostatic model of assessment. RESULTS: Cortisol bioavailability (total urine cortisol metabolites, urine free cortisol and cortisol binding globulin) was similar in both sexes. The 11-OH/11-oxo ratio was lower in females than males (median; 0.99 vs 1.3, P < 0.03) while thyroid status was similar. Females had higher percentage fat (median 47.7 vs 34.9, P < 0.01); total fat (median 39.5 vs 34.9 kg, P < 0.01), android fat (median 9.1 vs 6.6 kg, P < 0.01); gynoid fat (median; 9.9 vs 6.8 kg, P < 0.05) and lower insulin sensitivity (median 15.3 vs 30.6, P < 0.01). In all subjects, the 11-OH/11-oxo ratio was inversely related to body weight (P < 0.01), % fat (P < 0.05), total fat (P < 0.01), android fat (P < 0.01), gynoid fat, (P < 0.01) and directly correlated to insulin sensitivity, P < 0.01. Stepwise regression analysis showed gynoid fat to be the most important factor determining the 11-OH/11-oxo ratio. In 24 subjects (f:m, 8:16) on exogenous sex steroid therapy insulin sensitivity was similar but the sexual dimorphism of the 11-OH/11-oxo ratio remained unchanged (median; 1.0 vs 1.7, P < 0.05). The urine and serum F and E and their ratio (F/E) were similar in these groups. CONCLUSION: These data confirm the presence of sexual dimorphism in 11 beta-hydroxysteroid dehydrogenase activity in hypopituitary patients as described in normal individuals. This is the first in vivo evidence that this dimorphism is related to body composition. Our findings suggest that sexual dimorphism may be determined by the activity of type 1 and not type 2 11 beta-hydroxysteroid dehydrogenase.