Relapsing diabetes can result from moderately activating mutations in KCNJ11

Neonatal diabetes can either remit and hence be transient or else may be permanent. These two phenotypes were considered to be genetically distinct. Abnormalities of 6q24 are the commonest cause of transient neonatal diabetes (TNDM). Mutations in KCNJ11, which encodes Kir6.2, the pore-forming subunit of the ATP-sensitive potassium channel (K(ATP)), are the commonest cause of permanent neonatal diabetes (PNDM). In addition to diabetes, some KCNJ11 mutations also result in marked developmental delay and epilepsy. These mutations are more severe on functional characterization. We investigated whether mutations in KCNJ11 could also give rise to TNDM. We identified the three novel heterozygous mutations (G53S, G53R, I182V) in three of 11 probands with clinically defined TNDM, who did not have chromosome 6q24 abnormalities. The mutations co-segregated with diabetes within families and were not found in 100 controls. All probands had insulin-treated diabetes diagnosed in the first 4 months and went into remission by 7-14 months. Functional characterization of the TNDM associated mutations was performed by expressing the mutated Kir6.2 with SUR1 in Xenopus laevis oocytes. All three heterozygous mutations resulted in a reduction in the sensitivity to ATP when compared with wild-type (IC(50) approximately 30 versus approximately 7 microM, P-value for is all <0.01); however, this was less profoundly reduced than with the PNDM associated mutations. In conclusion, mutations in KCNJ11 are the first genetic cause for remitting as well as permanent diabetes. This suggests that a fixed ion channel abnormality can result in a fluctuating glycaemic phenotype. The multiple phenotypes associated with activating KCNJ11 mutations may reflect their severity in vitro.     

Acute health effects of the Sea Empress oil spill

STUDY OBJECTIVE: To investigate whether residents in the vicinity of the Sea Empress tanker spill suffered an increase in self reported physical and psychological symptoms, which might be attributable to exposure to crude oil. DESIGN: Retrospective cohort study; postal questionnaire including demographic details, a symptom checklist, beliefs about health effects of oil and the Hospital Anxiety and Depression and SF-36 mental health scales. SETTING: Populations living in four coastal towns on the exposed south Pembrokeshire coast and two control towns on the unexposed north coast. PATIENTS: 539 exposed and 550 unexposed people sampled at random from the family health services authority age-sex register who completed questionnaires. MAIN RESULTS: Adjusted odds ratios for self reported physical symptoms; scores on the Hospital Anxiety and Depression and SF-36 mental health scales, in 1089 people who responded out of a possible 1585 (69%). CONCLUSIONS: Living in areas exposed to the crude oil spillage was significantly associated with higher anxiety and depression scores, worse mental health; and self reported headache (odds ratio = 2.35, 95% CI 1.56, 3.55), sore eyes (odds ratio = 1.96, 95% CI 1.06, 3.62), and sore throat (odds ratio = 1.70, 95% CI 1.12, 2.60) after adjusting for age, sex, smoking status, anxiety, and the belief that oil had affected health. People living in exposed areas reported higher rates of physical and psychological symptoms than control areas. Symptoms significantly associated with exposure after adjustment for anxiety and health beliefs were those expected from the known toxicological effect of oil, suggesting a direct health effect on the exposed population.     

Genetic and clinical heterogeneity of Stickler syndrome.

We have studied 6 multigeneration Stickler syndrome families. Manifestations of the syndrome in the families included myopia, deafness, arthritis, characteristic facial changes with "flat" midface and cleft palate, although not all these were present in all families. COL2A1 has been implicated as a gene which can give rise to Stickler syndrome based on evidence from 2 large families which each showed significant linkage between the disease locus and restriction fragment length polymorphisms for the gene (Francomano CA, Lieberfarb RM, Hirose T, Maumenee IH, Streeten EA, Meyers DA, Pyeritz RE (1987): Genomics 1:293-296; Knowlton RG, Weaver EJ, Struyk AF, Knobloch WH, King RA, Norris K, Shamban A, Uitoo J, Jimenez SA, Prockop DJ (1989): Am J Hum Genet 45:681-688). We have found crossovers between the disease locus and COL2A1 in 2 families with Stickler syndrome. This could be explained by either genetic heterogeneity or the actual mutation being in a closely linked, currently unrecognized gene. We found a weakly positive overall lod score (z = 0.96 at theta = 0.10) suggesting that genetic heterogeneity is a more likely explanation. In one family, with typical findings, a translocation t5;17 (q15:q23) was found to segregate with the disease in 4 affected relatives. In view of the possible heterogeneity, although no crossovers with COL2A1 were seen in this family, either of these breakpoints could be the position of a further disease causing gene.     

Cancer in the elderly patient. Unique aspects of presentation, management and screening.

The high incidence of cancer in the rapidly expanding geriatric population presents a major challenge to the health care field. Since most cancers present and behave similarly in both older and younger persons, similar approaches to management must be considered in both. The elderly, however, are a heterogeneous group with individuals demonstrating varying degrees of comorbidity and physiologic change. Decisions, therefore, should be based on a sound knowledge of geriatric assessment and the factors important for "successful" aging rather than on chronological age alone.     

Donor bone marrow-derived chimeric cells present in renal transplant recipients infused with donor marrow. I. Potent regulators of recipient antidonor immune responses

BACKGROUND: Even though a number of transplant centers have adopted donor-specific bone marrow cell (DBMC) infusions to enhance donor cell chimerism, to date there has been no direct evidence linking chimerism with tolerance induction in human organ transplant recipients. METHODS: Cells of donor phenotype were isolated 1 year postoperatively from the peripheral blood lymphocytes and iliac crest bone marrow of 11 living-related-donor (LRD) renal transplant recipients, who had received perioperative donor bone marrow cell infusions. These recipient-derived donor (RdD) cells were characterized phenotypically by flow cytometric analysis and functionally as modulators in mixed lymphocyte reaction (MLR) and cell-mediated lympholysis (CML) assays. RESULTS: The yield of RdD cells ranged from 0.1 to O.9% of the starting material with the majority being TcRalphabeta, CD3 positive T cells, a substantial percentage of which coexpressed CD28. At 1 year posttransplant almost 50% of the LRD-kidney/DBMC recipients tested so far exhibited donor-specific unresponsiveness in MLR (7/17) and CML (6/13) reactions and this trend was further enhanced at 23 years. In the recipients with residual positive antidonor immune responses, the RdD cells inhibited recipient antidonor MLR and CML responses significantly more strongly than freshly isolated and similarly treated iliac crest bone marrow cells from the donor. RdD cells also inhibited the MLR of the recipient to third party allogeneic stimulator cells; however, this nonspecific effect was significantly weaker than specific inhibition. We also established long-term bone marrow cultures stimulated every 2 weeks with irradiated alogeneic feeder cells, that had similar functional properties thus possibly providing us with an in vitro correlate the RdD cells. CONCLUSIONS: These results clearly support the notion that the infused donor cells play a positive role in the induction and/or maintenance of transplant tolerance.     

Phenotypic diversity in siblings with partial androgen insensitivity syndrome

The androgen insensitivity syndrome is a heterogeneous disorder with a wide spectrum of phenotypic abnormalities, ranging from complete female to ambiguous forms that more closely resemble males. The primary abnormality is a defective androgen receptor protein due to a mutation of the androgen receptor gene. This prevents normal androgen action and thus leads to impaired virilisation. A point mutation of the androgen receptor gene affecting two siblings with partial androgen insensitivity syndrome is described. One had cliteromegaly and labial fusion and was raised as a girl, whereas the other sibling had micropenis and penoscrotal hypospadias and was raised as a boy. Both were shown to have the arginine 840 to cysteine mutation. The phenotypic variation in this family is thus dependent on factors other than abnormalities of the androgen receptor gene alone.     

Actuarial survival in the premature infant less than 30 weeks' gestation

OBJECTIVE: Because survival from admission to discharge does not provide parents and physicians information about future life expectancy in the premature neonate, we characterized the actuarial survival, defined as the future life expectancy from a given postnatal age, in a large inborn population of premature infants < 30 weeks' gestation. STUDY DESIGN: We determined daily actuarial survival of 1925 inborn infants (23 to 29 weeks' gestation) admitted to the Baylor Affiliated Nurseries from July 1986 through December 1994, stratified by 100-g birth weight and by 1-week gestational-age intervals. RESULTS: In the 501- to 600-g birth weight stratum, actuarial survival improved from 31% at birth, to 61% on day of life 7, and then to 75% on day of life 28; in the 901- to 1000-g birth weight stratum, actuarial survival improved from 88%, to 94%, and then to 98% throughout the same times, respectively. Similar trends were obtained when data were stratified by gestational age. CONCLUSIONS: Survival in the smallest infants improves dramatically during the first few days of life, but there is a significant risk for late death in the smallest of these infants.