KCNJ11 activating mutations in Italian patients with permanent neonatal diabetes

Permanent neonatal diabetes mellitus (PNDM) is a rare condition characterized by severe hyperglycemia constantly requiring insulin treatment from its onset. Complete deficiency of glucokinase (GCK) can cause PNDM; however, the genetic etiology is unknown in most PNDM patients. Recently, heterozygous activating mutations of KCNJ11, encoding Kir6.2, the pore forming subunit of the ATP-dependent potassium (K(ATP)) channel of the pancreatic beta-cell, were found in patients with PNDM. Closure of the K(ATP) channel exerts a pivotal role in insulin secretion by modifying the resting membrane potential that leads to insulin exocytosis. We screened the KCNJ11 gene in 12 Italian patients with PNDM (onset within 3 months from birth) and in six patients with non-autoimmune, insulin-requiring diabetes diagnosed during the first year of life. Five different heterozygous mutations were identified: c.149G>C (p.R50P), c.175G>A (p.V59M), c.509A>G (p.K170R), c.510G>C (p.K170N), and c.601C>T (p.R201C) in eight patients with diabetes diagnosed between day 3 and 182. Mutations at Arg50 and Lys170 residues are novel. Four patients also presented with motor and/or developmental delay as previously reported. We conclude that KCNJ11 mutations are a common cause of PNDM either in isolation or associated with developmental delay. Permanent diabetes of non autoimmune origin can present up to 6 months from birth in individuals with KCNJ11 and EIF2AK3 mutations. Therefore, we suggest that the acronym PNDM be replaced with the more comprehensive permanent diabetes mellitus of infancy (PDMI), linking it to the gene product (e.g., GCK-PDMI, KCNJ11-PDMI) to avoid confusion between patients with early-onset, autoimmune type 1 diabetes.     

Tyrosine phosphatase-like protein (IA-2) and glutamic acid decarboxylase (GAD65) autoantibodies: a study of Chinese patients with diabetes mellitus

Type 1 diabetes in most Asian populations may not have a salient autoimmune basis when assessed with single determinations of the major markers, islet cell antibodies (ICAs) and glutamic acid decarboxylase antibodies (GAD65ab). With the inclusion of antibodies to tyrosine phosphatase-like protein IA-2 (IA-2ab) as an additional major marker, we re-examined autoimmune diabetes in a group of Chinese patients. We studied 272 subjects at various stages of disease with blood samples procured for biochemical analysis. ICAs were measured by immunofluorescence, GAD65ab and IA-2ab by radioimmunoassay. Sixty-seven patients fulfilled clinical diagnosis of type 1 diabetes and the remaining 205 patients were type 2. Prevalence of single autoantibody type in recent-onset type 1 diabetes ( < 1 year duration; n = 47) showed 10.6% with ICAs, 44.7% GAD65ab and 36.2% IA-2ab. GAD65ab account for more than two-thirds of the markers found in type 1 diabetes. Combined analysis further showed that 51.1% had at least one antibody type, 31.9% with two or more antibodies and 8.5% with all three antibodies. Islet autoimmunity presence in childhood-onset type 1 diabetes improved with the addition of IA-2ab, though less impact was seen in the adult-onset. Similarly, combined analysis for type 2 patients with recent diabetes showed a modest increase to 13% with islet autoimmunity compared to 8% when assessed by GAD65ab alone. Combining IA-2ab and GAD65ab assays results detected slightly more immune-mediated diabetes, compared to using a single GAD65ab determination. Non-autoimmune causes need to be considered in the pathogenesis of type 1 diabetes in Chinese, particularly in adults.     

Identification of 21 novel glucokinase (GCK) mutations in UK and European Caucasians with maturity-onset diabetes of the young (MODY)

Maturity-onset diabetes of the young (MODY) resulting from mutations in the glucokinase (GCK) gene accounts for approximately 20% of MODY in the UK. We have performed fluorescent single stranded conformation polymorphism (F-SSCP) analysis or direct sequencing of the GCK gene in 212 patients referred as part of a research cohort or for diagnostic molecular genetic testing. Mutation screening has identified 43 different mutations in 61 individuals, of which 21 are novel. This report details the mutations identified and their associated clinical features.     

A 3D MRI sequence for computer assisted surgery of the lumbar spine

The aim of this research was to develop a magnetic resonance (MR) sequence capable of producing images suitable for use with computer assisted surgery (CAS) of the lumbar spine. These images needed good tissue contrast between bone and soft tissue to allow for image segmentation and generation of a 3D-surface model of the bone for surface registration. A 3D double echo fast gradient echo sequence was designed. Images were filtered for noise and non-uniformity and combined into a single data set. Registration experiments were carried out to directly compare segmentation of MR and computed tomography (CT) images using a physical model of a spine. These experiments showed the MR data produced adequate surface registration in 90% of the experiments compared to 100% with CT data. The MR images acquired using the sequence and processing described in this article are suitable to be used with CAS of the spine.     

Indirect dopamine agonists augment the locomotor activating effects of the kappa-opioid receptor agonist U-50,488 in preweanling rats

kappa-Opioid receptor agonists (e.g., enadoline or U-50,488) increase the locomotor activity of preweanling rats, while the same drugs depress the locomotor activity of adults. Curiously, direct stimulation of dopamine (DA) D2-like receptors fully attenuates the U-50,488-induced locomotor activity of preweanling rats. The purpose of the present study was to determine whether indirect DA agonists (i.e., cocaine, methylphenidate, and amphetamine) would also attenuate U-50,488's behavioral effects. In two experiments, 17-day-old rats were injected with saline or U-50,488 (5 mg/kg, sc) and locomotor activity and stereotyped sniffing were assessed. After 20 min, the saline- and U-50,488-pretreated rats were injected with saline, cocaine (5, 10, or 20 mg/kg, i.p.), methylphenidate (10 or 20 mg/kg, i.p.), amphetamine (2.5 or 5 mg/kg, i.p.), or the direct D2-like receptor agonist NPA (1 mg/kg, i.p.). As expected, U-50,488 dramatically enhanced the locomotor activity of 17-day-old rats, while attenuating the stereotyped sniffing caused by indirect and direct DA agonists. All three indirect DA agonists augmented U-50,488's locomotor activating effects across the initial 10 min of testing and then activity declined to U-50,488 control values. Direct stimulation of DA receptors produced nearly opposite effects because NPA attenuated U-50,488-induced locomotor activity across the entire testing session. It is uncertain why direct and indirect DA agonists affected U-50,488-induced locomotor activity differently, but the relative amount of DA D1-like receptor activation is probably not responsible.     

Efficacy and tolerability of a new estradiol delivering matrix patch (Estraderm MX) in postmenopausal women

OBJECTIVE: To examine the efficacy and tolerability of a new matrix patch delivering estradiol (E2 Matrix) at doses of 0.05 and 0.10 mg per day (Estraderm MX 50, 100) in the treatment of moderate to severe postmenopausal symptoms. METHODS: A total of 254 postmenopausal women were randomized to receive treatment with E2 Matrix 0.10 mg (N = 86), E2 Matrix 0.05 mg (N = 82), or placebo (N = 86) in a double-blind, double-dummy fashion for a period of 12 weeks continuously. Patches were applied twice weekly to the buttocks with each patient wearing two patches at all times. The primary efficacy criterion was the difference from baseline of the mean number of moderate to severe hot flushes per 24 h during the last 2 weeks of treatment. Other efficacy variables included reduction in hot flushes at 4 and 8 weeks, reduction in daytime flushing and night sweats, and Kupperman Index at 4, 8, and 12 weeks. RESULTS: E2 Matrix 0.10 and 0.05 mg were both significantly superior to placebo in reducing hot flushes per 24 h after 4, 8, and 12 weeks of treatment (P < 0.001). Also, for all other efficacy parameters studied, both dosage strengths of E2 Matrix were statistically significantly superior to placebo at all time points (P < 0.001). Local tolerability was good in both groups. A slight increase in estrogen related adverse effects (breast tenderness, leukorrhoea) was seen with the 0.10 mg patch. Adhesion of patches and compliance were good. Overall systemic tolerability was good in both treated groups. However, a 4.8% overall incidence of endometrial hyperplasia was observed in patients with an intact uterus. CONCLUSIONS: This new matrix patch offers an effective and well tolerated dosage form for delivery of 0.05 and 0.1 mg estradiol per day. It may be particularly suitable for those women who experience local sensitivity to alcohol-containing systems. In light of the observed hyperplasia after treatment in five patients, estrogen therapy should as yet be supplemented monthly with a progestogen in women with an intact uterus.     

Determinants of CD4 Counts Among HIV-Negative Ethiopians: Role of Body Mass Index,Gender, Cigarette Smoking,Khat (<Emphasis Type="Italic">Catha Edulis</Emphasis>) Chewing,and Possibly Altitude?

To study the determinants of CD4% and CD4 counts among HIV-negative Ethiopians, and to identify factors susceptible to explain the low CD4 counts observed among Ethiopian subjects. Cohort studies among factory workers in Akaki and Wonji, Ethiopia. Clinical and laboratory examinations, including determination of HIV serological status and T-cell subsets, were performed during follow-up visits every six months. In addition, micronutrients (retinol, carotenoids, tocopherol, transferrin receptor, and selenium) plasma concentrations were determined in a subset of 38 HIV-positive and 121 HIV-negative participants. HIV-negative participants with at least one CD4 count measurement were 157 females in Akaki, 203 males in Akaki, and 712 males in Wonji. CD4 counts were independently and positively associated with body mass index (through an increase in lymphocyte counts), female gender (through an increase in CD4%), cigarette smoking (through an increase in CD4%), khat chewing (through an increase in both lymphocyte counts and CD4%), and Akaki study site (through a large increase in lymphocyte counts compensating a decrease in CD4%). Intestinal parasitic infections were not associated with CD4% or CD4 counts. Retinol, carotenoids, and -tocopherol plasma concentrations decreased with HIV infection and advancing immunosuppression, but were not associated with CD4 counts among HIV-negative subjects. Low body mass index among Ethiopians may have contributed to their overall low CD4 counts. Other factors remain to be elucidated.     

Endometrial and colorectal tumors from patients with hereditary nonpolyposis colon cancer display different patterns of microsatellite instability

The colorectum and uterine endometrium are the two most commonly affected organs in hereditary nonpolyposis colon cancer (HNPCC), but the genetic basis of organ selection is poorly understood. As tumorigenesis in HNPCC is driven by deficient DNA mismatch repair (MMR), we compared its typical consequence, instability at microsatellite sequences, in colorectal and endometrial cancers from patients with identical predisposing mutations in the MMR genes MLH1 or MSH2. Analysis of non-coding (BAT25, BAT26, and BAT40) and coding mononucleotide repeats (MSH6, MSH3, MLH3, BAX, IGF2R, TGF beta RII, and PTEN), as well as MLH1- and MSH2-linked dinucleotide repeats (D3S1611 and CA7) revealed significant differences, both quantitative and qualitative, between the two tumor types. Whereas colorectal cancers displayed a predominant pattern consisting of instability at the BAT loci (in 89% of tumors), TGF beta RII (73%), dinucleotide repeats (70%), MSH3 (43%), and BAX (30%), no such single pattern was discernible in endometrial cancers. Instead, the pattern was more heterogeneous and involved a lower proportion of unstable markers per tumor (mean 0.27 for endometrial cancers versus 0.45 for colorectal cancers, P < 0.001) and shorter allelic shifts for BAT markers (average 5.1 bp for unstable endometrial cancers versus 9.3 bp for colorectal cancers, P < 0.001). Among the individual putative "target" loci, PTEN instability was associated with endometrial cancers and TGF beta RII instability with colon cancers. The different instability profiles in endometrial and colorectal cancers despite identical genetic predisposition underlines organ-specific differences that may be important determinants of the HNPCC tumor spectrum.