Identical and Nonidentical Twins: Risk and Factors Involved in Development of Islet Autoimmunity and Type 1 Diabetes

OBJECTIVE

There are variable reports of risk of concordance for progression to islet autoantibodies and type 1 diabetes in identical twins after one twin is diagnosed. We examined development of positive autoantibodies and type 1 diabetes and the effects of genetic factors and common environment on autoantibody positivity in identical twins, nonidentical twins, and full siblings.

RESEARCH DESIGN AND METHODS

Subjects from the TrialNet Pathway to Prevention Study (N = 48,026) were screened from 2004 to 2015 for islet autoantibodies (GAD antibody [GADA], insulinoma-associated antigen 2 [IA-2A], and autoantibodies against insulin [IAA]). Of these subjects, 17,226 (157 identical twins, 283 nonidentical twins, and 16,786 full siblings) were followed for autoantibody positivity or type 1 diabetes for a median of 2.1 years.

RESULTS

At screening, identical twins were more likely to have positive GADA, IA-2A, and IAA than nonidentical twins or full siblings (all P < 0.0001). Younger age, male sex, and genetic factors were significant factors for expression of IA-2A, IAA, one or more positive autoantibodies, and two or more positive autoantibodies (all P ≤ 0.03). Initially autoantibody-positive identical twins had a 69% risk of diabetes by 3 years compared with 1.5% for initially autoantibody-negative identical twins. In nonidentical twins, type 1 diabetes risk by 3 years was 72% for initially multiple autoantibody-positive, 13% for single autoantibody-positive, and 0% for initially autoantibody-negative nonidentical twins. Full siblings had a 3-year type 1 diabetes risk of 47% for multiple autoantibody-positive, 12% for single autoantibody-positive, and 0.5% for initially autoantibody-negative subjects.

CONCLUSIONS

Risk of type 1 diabetes at 3 years is high for initially multiple and single autoantibody-positive identical twins and multiple autoantibody-positive nonidentical twins. Genetic predisposition, age, and male sex are significant risk factors for development of positive autoantibodies in twins.

Characterization of Differentiated SH-SY5Y as Neuronal Screening Model Reveals Increased Oxidative Vulnerability

The immortalized and proliferative cell line SH-SY5Y is one of the most commonly used cell lines in neuroscience and neuroblastoma research. However, undifferentiated SH-SY5Y cells share few properties with mature neurons. In this study, we present an optimized neuronal differentiation protocol for SH-SY5Y that requires only two work steps and 6 days. After differentiation, the cells present increased levels of ATP and plasma membrane activity but reduced expression of energetic stress response genes. Differentiation results in reduced mitochondrial membrane potential and decreased robustness toward perturbations with 6-hydroxydopamine. We are convinced that the presented differentiation method will leverage genetic and chemical high-throughput screening projects targeting pathways that are involved in the selective vulnerability of neurons with high energetic stress levels.

One stop fertility clinic

The objective of this study was to determine the feasibility and acceptability of out-patient based investigation of infertile couples using a prospective observational study based in a large undergraduate teaching hospital. We studied couples referred to secondary care for investigation of their infertility. Investigations involved pelvic ultrasound, diagnostic hysteroscopy and culdoscopy. The main outcome measures were feasibility of investigations, findings, patient views, and a management plan.

RESULTS

199 of 347 (57.3%) couples referred met our selection criteria, and 162 of this group have attended. Thirty-one (19.1%) were judged to be unsuitable for culdoscopy, and culdoscopy failed in a further 29 (17.9%). The average time for the three procedures was 41.2 (SD 17.2) minutes, and over 1/3 of patients were found to have pelvic pathology. The investigations were well tolerated and there was only one complication necessitating admission to hospital. Most patients appreciated the need for a single hospital visit and the availability of immediate results.

CONCLUSIONS

A One Stop approach to the investigation of infertility is attractive but not suitable for or desired by all infertile couples. Organisational issues were also identified.

Outpatient hysteroscopy: traditional versus the 'no-touch' technique

OBJECTIVE

To assess whether outpatient hysteroscopy using the 'no-touch' technique confers any advantages in terms of patient discomfort over the traditional technique.

DESIGN

Prospective randomised controlled study.

SETTING

Outpatient hysteroscopy clinic in a large university undergraduate teaching hospital.

POPULATION

All women referred for outpatient hysteroscopy in a 12-month period.

INTERVENTIONS

Women were randomised to undergo either traditional saline hysteroscopy requiring the use of a speculum and tenaculum, or a 'no-touch' vaginoscopic hysteroscopy which does not require a speculum or tenaculum. Each group was further subdivided to have hysteroscopy with either a 2.9-mm or 4-mm hysteroscope. Patients were asked to complete pre- and postprocedure questionnaires ranking pain scores.

MAIN OUTCOME MEASURES

The relative success of each of these techniques, requirement for local anaesthetic and pain scores at different times during the hysteroscopy were recorded at the end of the procedure. The time taken to carry out each procedure was also measured.

RESULTS

One hundred and twenty women were recruited in this study: 60 were randomised to traditional hysteroscopy and 60 to 'no-touch' hysteroscopy. The overall success rate for hysteroscopy was 99%. There was no significant difference in the requirement for local anaesthetic between the two groups, but those who underwent 'no-touch' hysteroscopy with a 2.9-mm hysteroscope had the lowest requirement of local anaesthetic (10% compared with 27% in the no-touch hysteroscopy with a 4-mm hysteroscope group). The time taken to perform hysteroscopy and biopsy was significantly shorter with 'no-touch' hysteroscopy (5.9 vs 7.8 min; difference 1.9, 95% CI 0.7-3.1). There were no differences in pain scores between the groups at different times during hysteroscopy.

CONCLUSIONS

'No-touch' or vaginoscopic hysteroscopy is significantly faster to perform than the traditional technique. Although there was no difference in pain scores between the two techniques, local anaesthetic requirements were least in those who underwent 'no-touch' hysteroscopy with a narrow bore hysteroscope.

Biodegradation potential of photocatalyzed surfactant washwater

Enhanced release of hydrophobic compounds from a soil matrix can be achieved by use of soil-washing or soil-flushing using various surfactants. However, the surfactants used in achieving the desorption of organic contaminants may also cause a problem in subsequent removal/disposal of these contaminants. UV radiation in the presence of TiO2 as a pre-treatment step to achieve initial (or partial) breakdown of naphthalene and Sodium Dodecyl Sulfate (SDS) using batch experiments indicated that 56% to 88% naphthalene degradation occurred within 30 minutes to one hour. Preliminary results on the estimate of the batch aerobic biodegradation potential of photocatalyzed washwater containing naphthalene and SDS suggested that SDS was the major carbon and energy source for an activated sludge enrichment culture and an enrichment culture obtained from microorganisms at a contaminated site. Continuous-flow stirred tank reactors (CSTRs) with with a solids retention time (SRT) of 4 days were not effective, but an SRT of 8 days was successful in biodegrading the naphthalene and surfactant. These results indicated that photocatalytic treatment as a pre-treatment step followed by a biodegradation step may offer potential in cleaning up surfactant washwaters containing organic contaminants.

Reversible decreases in ATP and PCr concentrations in anoxic turtle brain

A hallmark of anoxia tolerance in western painted turtles is relative constancy of tissue adenylate concentrations during periods of oxygen limitation. During anoxia heart and brain intracellular compartments become more acidic and cellular energy demands are met by anaerobic glycolysis. Because changes in adenylates and pH during anoxic stress could represent important signals triggering metabolic and ion channel down-regulation we measured PCr, ATP and intracellular pH in turtle brain sheets throughout a 3-h anoxic-re-oxygenation transition with 31P NMR. Within 30 min of anoxia, PCr levels decrease 40% and remain at this level during anoxia. A different profile is observed for ATP, with a statistically significant decrease of 23% occurring gradually during 110 min of anoxic perfusion. Intracellular pH decreases significantly with the onset of anoxia, from 7.2 to 6.6 within 50 min. Upon re-oxygenation PCr, ATP and intracellular pH recover to pre-anoxic levels within 60 min. This is the first demonstration of a sustained reversible decrease in ATP levels with anoxia in turtle brain. The observed changes in pH and adenylates, and a probable concomitant increase in adenosine, may represent important metabolic signals during anoxia.

Leptin prevents posthibernation weight gain but does not reduce energy expenditure in arctic ground squirrels

In mammals, leptin reduces energy intake and may increase energy expenditure as a means to maintain body weight and/or adiposity at an appropriate level. Hibernating mammals seasonally alter body mass, food intake, and body composition and, therefore, represent an attractive model for investigating the physiological regulation of changing body mass and adiposity. Previous experiments in our laboratory demonstrated that administration of mouse recombinant leptin reduces food intake and body weight in arctic ground squirrels during prehibernation fattening. In addition, leptin appeared to reduce metabolic efficiency (weight gain per unit of energy intake). This result suggests that reduced food intake alone may not account for the observed weight loss. Here, we describe the effect of a 3-week constant infusion of leptin given to posthibernation arctic ground squirrels on food consumption and energy expenditure. Mouse recombinant leptin (1 mg/ml) was administered through subcutaneously implanted mini-osmotic pumps (10 microliters/hr flow rate). Resting metabolic rate was monitored before and during the 3-week leptin administration period by indirect calorimetry. Body temperature and locomotory activity were monitored continuously by abdominal radiotransmitters. At the end of the leptin administration period, thermogenic capacity was evaluated by measuring brown fat uncoupling protein-1 mRNA and protein levels. Leptin administration resulted in reduced food intake and prevented posthibernation weight gain, but it did not alter any of the measured parameters of energy expenditure.

Gender differences in recalled parental childrearing behaviors and adult self-esteem

A retrospective questionnaire study investigated gender differences in the relations between the self-reported self-esteem of 155 psychiatric adult outpatients and their recalled experience of their parents' behavior toward them as children. There were no significant sex differences in degree of self-esteem. However, it had a higher correlation to parenting variables for the men than for the women, with maternal predictor variables accounting for 36% and paternal predictors accounting for 32% of the variance in the men's self-esteem. Neither combined maternal nor combined paternal variables were significant predictors for women. For men, parental acceptance/ autonomy was significantly and positively related and inconsistency negatively related to self-esteem. Paternal rejection but not maternal rejection was significantly associated with low self-esteem only for the women. The greater amount of variance explained by childrearing variables in the men's self-esteem scores was attributed to the earlier ego development and consequent increased individuation in women.

The family of genes encoding odorant receptors in the channel catfish

The anatomical and numerical simplicity of the fish olfactory system has led us to examine the family of olfactory receptors expressed in the catfish. We have identified a family of genes encoding seven transmembrane domain receptors that share considerable homology with the odorant receptors of the rat. The size of the catfish receptor repertoire appears to be far smaller than in mammals. Analysis of the nucleotide sequences suggests that these receptor genes have undergone positive Darwinian selection to generate enhanced diversity within the putative odorant-binding domains. Individual receptor clones anneal with 0.5%-2% of the olfactory neurons, suggesting that a single cell expresses only a small subset of distinct odorant receptors. Each cell, therefore, possesses a unique identity defined by the receptors it expresses. These data suggest that the brain may discriminate among odors by determining which neurons have been activated.

R15 alpha 1 and R 15 alpha 2 peptides from Aplysia: comparison of bioactivity, distribution, and function of two peptides generated by alternative splicing

The mRNA precursor encoded by the R15 gene is alternatively spliced in different neurons to form two related variants, R15-1 and R15-2 mRNA. One of the peptides encoded by the R15-2 mRNA, the R15 alpha 1 peptide, is expressed in the endogenously bursting neuron R15 and mediates some of its central and peripheral synaptic actions. In this study we found that the R15 alpha 2 peptide, which is encoded by the R15-1 mRNA, is synthesized in other neurons in the abdominal ganglion and is also bioactive. The R15 alpha 1 and R15 alpha 2 peptides were found to exert many similar actions on the cardiovascular, digestive, respiratory, and reproductive systems. However, the differences between many of the pharmacological effects of the R15 alpha 1 and R15 alpha 2 peptides indicate that alternative splicing in this system results in two functionally different peptides. Widespread immunoreactivity was found for an antibody directed against the R15 alpha 2 peptide, both in the central nervous system and the periphery. But because of the shared sequence with the R15 alpha 1 peptide, the antibody cross-reacts with the R15 alpha 1 peptide. To distinguish immunocytochemically between the two peptides, we also raised a second antibody that recognizes only the R15 alpha 1 peptide. This antibody labeled the cell body of only one neuron in the central nervous system, R15, although widespread immunoreactivity was found in axons and varicosities in the periphery.

A novel multigene family may encode odorant receptors: a molecular basis for odor recognition

The mammalian olfactory system can recognize and discriminate a large number of different odorant molecules. The detection of chemically distinct odorants presumably results from the association of odorous ligands with specific receptors on olfactory sensory neurons. To address the problem of olfactory perception at a molecular level, we have cloned and characterized 18 different members of an extremely large multigene family that encodes seven transmembrane domain proteins whose expression is restricted to the olfactory epithelium. The members of this novel gene family are likely to encode a diverse family of odorant receptors.

Interrelations between ego functions and personality traits: their relation to psychotherapy outcome

Ninety consecutive admissions to a large outpatient clinic of a municipal hospital completed two self-report questionnaires: the Self-Evaluation Questionnaire (SEQ) which consists of four 10-item scales that assessed four areas of ego functioning; and the 89-item Personality Profile Index (PPI) that provided measures of eight dimensions of personality traits and also a measure of conflict. Results indicated that the four measures of ego functioning had good internal consistency, and three of the four ego functions had a highly similar pattern of relations to the personality trait dimensions and to the conflict measure. It thus appears that each set of constructs amplifies and sheds light on the other. Two of the ego function measures were significant predictors of psychotherapy outcome. They correlated highly with one another and also with a third measure of ego functioning. This fact, together with the similarity of their correlations with the personality traits, suggests that these ego functions represent different aspects of an underlying construct that could be called Ego Strength. Therefore, combining the three ego functions into a 30-item Ego Strength measure could provide an even more sensitive predictor of therapy outcome and a useful new instrument for psychotherapy research.

A comparative study on the effects of brotizolam and flurazepam on sleep and performance in the elderly

This study was undertaken to compare the effects of 0.25 mg of brotizolam, 15 mg of flurazepam, and placebo on the sleep and performance of elderly subjects with chronic insomnia during a 2-week period of administration. Thirty-six male and female subjects who ranged in age from 60-72 years were divided into three treatment groups. All groups received placebo on the first three study nights, the active drug or placebo on the next 14 nights, and placebo again on the two following withdrawal nights. Sleep was assessed by means of questionnaires, and residual effects during the day were studied by means of the multiple sleep latency test and a variety of memory, performance, and vigilance tests. Sleep improved with all treatments. Rebound insomnia was noted on brotizolam withdrawal; flurazepam withdrawal had a milder impact. At the end of this 19-night study, only the placebo-treated group was sleeping significantly longer than at baseline. Both drug treatments increased daytime sleepiness and impaired performance on the first day after their administration. These effects waned after 2 weeks of treatment with brotizolam, but not flurazepam. The results of this study affirm the increased sensitivity of elderly subjects to benzodiazepine hypnotics and their indication for acute or intermittent insomnia, rather than for the more chronic forms of this disorder.

A comparative study on the effects of brotizolam and flurazepam on sleep and performance in the elderly

This study was undertaken to compare the effects of 0.25 mg of brotizolam, 15 mg of flurazepam, and placebo on the sleep and performance of elderly subjects with chronic insomnia during a 2-week period of administration. Thirty-six male and female subjects who ranged in age from 60-72 years were divided into three treatment groups. All groups received placebo on the first three study nights, the active drug or placebo on the next 14 nights, and placebo again on the two following withdrawal nights. Sleep was assessed by means of questionnaires, and residual effects during the day were studied by means of the multiple sleep latency test and a variety of memory, performance, and vigilance tests. Sleep improved with all treatments. Rebound insomnia was noted on brotizolam withdrawal; flurazepam withdrawal had a milder impact. At the end of this 19-night study, only the placebo-treated group was sleeping significantly longer than at baseline. Both drug treatments increased daytime sleepiness and impaired performance on the first day after their administration. These effects waned after 2 weeks of treatment with brotizolam, but not flurazepam. The results of this study affirm the increased sensitivity of elderly subjects to benzodiazepine hypnotics and their indication for acute or intermittent insomnia, rather than for the more chronic forms of this disorder.

Purification and sequencing of neuropeptides contained in neuron R15 of Aplysia californica

R15 is a large identified neuron present in the abdominal ganglion of the mollusc Aplysia. Previous studies have indicated that this neuron may play a role in water balance and possibly renovascular functions. A peptidic factor contained in the neuron R15 has been shown to increase the water content of Aplysia. To determine the structure of the peptides contained in R15, we purified the extracts of 820 R15 cells by means of two steps of reverse-phase HPLC. The purification yielded a number of peptides, only one of which, R15 alpha 1, resulted in water uptake when injected into animals. Determination of the amino acid content and sequence analysis of the R15 alpha 1 peptide demonstrated that this peptide contains 38 residues, including two cysteines. The peptide failed to react with iodoacetate, indicating that the two cysteines are connected by a disulfide bridge. To confirm the assigned structure, the peptide was synthesized with a disulfide bridge. The chromatographic properties and bioactivity of the synthetic material were identical to those of the native peptide. Several other R15 peptides were inactive in the bioassay for water uptake. The sequence of one of these peptides (R15 beta) was determined, and it was established that the peptide contains 28 residues. Amino acid analysis of three other peaks was performed. One of these peaks contained a peptide (R15 beta f) whose amino acid composition suggests that it is a fragment of the R15 beta peptide. The other two peaks contained peptides with identical amino acid compositions, suggesting that they are variants of a single peptide (R15 gamma). The amino acid sequences of all the peptides identified in neuron R15 correspond to stretches of a polyprotein encoded by a recently sequenced R15 cDNA.

Effects of flurazepam and zopiclone on the performance of chronic insomniac patients: a study of ethanol-drug interaction

Three groups of ten middle-aged insomniac patients were treated with placebo, flurazepam, or zopiclone for 12 consecutive days in a study designed to compare the residual daytime effects of long-acting flurazepam and short-acting zopiclone on a variety of cognitive and motor tasks. These effects were examined independently and in combination with ethanol effects. The effects of the drugs on sleep parameters were also subjectively assessed by means of questionnaires during treatment and withdrawal. The study demonstrated persistent performance effects with flurazepam. Testing at the end of the treatment period showed that movement time was impaired in the flurazepam treated group. Flurazepam also enhanced the increment of movement time produced by ethanol. One subject became severely confused when given ethanol after using flurazepam for 12 days. None of these effects were found with zopiclone. The rapid elimination of zopiclone may account for these findings.

Driving ability after intravenous fentanyl or diazepam. A controlled double-blind study

Uncomfortable or moderately painful radiologic diagnostic and therapeutic procedures are being performed increasingly on outpatients. If sedation and analgesia are used, patients cannot drive themselves home or return rapidly to normal activities. This study compares the effect of fentanyl (100 micrograms), diazepam (7.5 mg), and placebo on driving ability of young volunteers as measured by the thacometer. Speed and accuracy were impaired at 30 and 120 minutes by both drugs, and by fentanyl more than diazepam. This study design may be suitable for the assessment of whether patients can drive safely after other analgesic drugs.

Effects of trace levels of nitrous oxide on psychomotor performance

Twenty-four male student volunteers were exposed to 50 ppm of nitrous oxide or air in an exposure chamber for 4 h in two experimental sessions. The subjects completed a battery of psychomotor tests during the final 40 min of the exposure sessions. Nitrous oxide, at this low concentration, did not produce any statistically significant changes in performance.

location Versus Distance in Determining Movement Accuracy

In a pursuit-tracking task consisting of 100 positioning movements between targets at 5 fixed positions, target location (proximity to the boundary of the task) varied independently of movement amplitude. Eighty-seven subjects performed 12 trials of the task, with target width (at 3 levels) as a between-subject variable. A microprocessor system detected the location of the end-point of each primary movement. Movement accuracy (measured as end-point dispersion not constant error) varied with target location but not movement amplitude, while movement time varied with both factors. The effect of target width on movement accuracy was less consistent. The observed effects are discussed in terms of a mass-spring model of muscular action. It is concluded that apart from having important consequences for the design of positioning experiments, these results call into question information-processing and impulse-variability theories which implicate movement amplitude in determining movement accuracy, and support theories which emphasize target location.

Measuring impaired performance with the NRC "stressalyser"

The NRC 'stressalyser' is a step-input subject-paced pursuit tracking task used to detect the effects of various extrinsic factors on skilled performance. It gives measures of reaction time, movement time, error score and overshoot score, each at four levels of the relevant within-task variable (directional probability, target distance or boundary distance). Several investigations have shown how these measures vary with such factors as sleep loss, time of day, alcohol, insulin-induced hypoglycaemia and diazepam, and thus demonstrate the applicability of the device to many applied problems of performance impairment.

Circadian rhythms of performance among workers in the Arctic

Subjects lving in the high Arctic carried out performance tests at the ends of the dark and light seasons and the intervening transitional seasons. In all four seasons, subjects showed circadian rhythms of performance. Rhythms for speed and accuracy were opposite in phase. The results show that normal rhythms are maintained when subjects follow a customary 24-h work pattern even though solar light-dark cycles are absent.

Listeria monocytogenes septic arthritis

Listeria monocytogenes was isolated from both the blood and the synovial fluid of a diabetic patient with a septic arthritis involving the ankle.

The sensory basis of target location

Overshoot rate in a target alignment task depends on the location of the target with reference to the operational boundary of the task. Subjects performed a step tracking task under four conditions combining pursuit and compensatory display modes with joystick and crank control devices. The boundary effect was found when the joystick was used but not the crank, while the display mode had no effect, indicating that subjects moved with respect to a frame of reference based on proprioceptive information. Movements were made according to the postures adopted, irrespective of the concomitant visual consequences.

Psychomotor test performance and sleep patterns of aircrew flying transmeridional routes

Pilots and flight attendants flying scheduled services between Vancouver and Tokyo and between Toronto and Rome were tested on a tracking task before and after flights in each direction. Flights were included in schedules involving both 24-h and 7-d layovers at the overseas station. During these periods, they recorded their sleep patterns. The data showed that, following flight, subjects made an immediate attempt to adapt their behaviour to local time and the changes in their performance scores could be interpreted on that basis. It was concluded that behavioural circadian rhythms adapt rapidly to a new time zone.

Sequences related to immunoglobulin kappa chain messenger RNA in T cells

We investigated by molecular hybridization whether T cells contain RNA sequences homologous to RNA which codes for immunoglobulin kappa-chain (k-chain). A radioactive probe of complementary DNA (cDNA) was prepared by transcription of purified k-chain mRNA from mouse myeloma MOPC-41 with reverse transcriptase (RNA-dependent-DNA nucleotidyltransferase) from avian myeloblastosis virus. The cDNA probably corresponded only to the constant region and 3'-terminus of k-chain mRNA. Kappa-chain cDNA was found to hybridize efficiently with RNA from both thymus cells and an established culture of thymoma cells. The thymus and thymoma cells contained 99.8% and 100% theta-positive cells, respectively. Quantitatively the average thymus T cell (thymus derived lymphocyte) contained about one half as much k-chain mRNA as the average spleen B cell ("bursa" dependent lymphocyte), whereas the thymoma cells contained only 1/33 as much. Control hybridizations of k-chain cDNA with myeloma and liver RNA support the conclusion that T cells in the thymus and in the thymoma cell line synthesize k-chain mRNA-like molecules. The thermal stability of hybrids of k-chain cDNA with RNA from spleen, thymus, thymoma, and another k-chain producing myeloma tumor was lower than that with MOPC-41 RNA. This finding may be due to the existence of several slightly different ck genes in the mouse as suggested by various control experiments.

Psychomotor performance during insulin-induced hypoglycemia

Subjects were given intravenous injections of insulin and/or saline on separate occasions and then tested on a pursuit-tracking task. Seven subjects showed clear clinical signs of hypoglycemia which were accompanied by a plasma glucose concentration of 32 mg/dl or less and by impaired tracking performance. Seven subjects showing no hypoglycemic signs despite insulin, and seven subjects receiving saline injections, showed no impairment in tracking. Impairment lasted from about the 15th to the 60th minute following injection, and was more readily apparent in response execution than response selection. There were no changes in accuracy of performance. Possible explanatory mechanisms, including neuroglycopenia, are discussed, and some implications for driving performance are noted.