Vitamin B12 and folate concentrations during pregnancy and insulin resistance in the offspring: the Pune Maternal Nutrition Study

AIMS/HYPOTHESIS

Raised maternal plasma total homocysteine (tHcy) concentrations predict small size at birth, which is a risk factor for type 2 diabetes mellitus. We studied the association between maternal vitamin B12, folate and tHcy status during pregnancy, and offspring adiposity and insulin resistance at 6 years.

METHODS

In the Pune Maternal Nutrition Study we studied 700 consecutive eligible pregnant women in six villages. We measured maternal nutritional intake and circulating concentrations of folate, vitamin B12, tHcy and methylmalonic acid (MMA) at 18 and 28 weeks of gestation. These were correlated with offspring anthropometry, body composition (dual-energy X-ray absorptiometry scan) and insulin resistance (homeostatic model assessment of insulin resistance [HOMA-R]) at 6 years.

RESULTS

Two-thirds of mothers had low vitamin B12 (<150 pmol/l), 90% had high MMA (>0.26 micromol/l) and 30% had raised tHcy concentrations (>10 micromol/l); only one had a low erythrocyte folate concentration. Although short and thin (BMI), the 6-year-old children were relatively adipose compared with the UK standards (skinfold thicknesses). Higher maternal erythrocyte folate concentrations at 28 weeks predicted higher offspring adiposity and higher HOMA-R (both p < 0.01). Low maternal vitamin B12 (18 weeks; p = 0.03) predicted higher HOMA-R in the children. The offspring of mothers with a combination of high folate and low vitamin B12 concentrations were the most insulin resistant.

CONCLUSIONS/INTERPRETATION

Low maternal vitamin B12 and high folate status may contribute to the epidemic of adiposity and type 2 diabetes in India.

A comparative review of generic quality-of-life instruments

The assessment of health-related quality of life (HR-QOL) is an essential element of healthcare evaluation. Hundreds of generic and specific HR-QOL instruments have been developed. Generic HR-QOL instruments are designed to be applicable across a wide range of populations and interventions. Specific HR-QOL measures are designed to be relevant to particular interventions or in certain subpopulations (e.g. individuals with rheumatoid arthritis). This review examines 7 generic HR-QOL instruments: (i) the Medical Outcomes Study 36-Item Short Form (SF-36) health survey; (ii) the Nottingham Health Profile (NHP); (iii) the Sickness Impact Profile (SIP); (iv) the Dartmouth Primary care Cooperative Information Project (COOP) Charts; (v) the Quality of Well-Being (QWB) Scale; (vi) the Health Utilities Index (HUI); and (vii) the EuroQol Instrument (EQ-5D). These instruments were selected because they are commonly used and/or cited in the English language literature. The 6 characteristics of an instrument addressed by this review are: (i) conceptual and measurement model; (ii) reliability; (iii) validity; (iv) respondent and administrative burden; (v) alternative forms; and (vi) cultural and language adaptations. Of the instruments reviewed, the SF-36 health survey is the most commonly used HR-QOL measure. It was developed as a short-form measure of functioning and well-being in the Medical Outcomes Study. The Dartmouth COOP Charts were designed to be used in everyday clinical practice to provide immediate feedback to clinicians about the health status of their patients. The NHP was developed to reflect lay rather than professional perceptions of health. The SIP was constructed as a measure of sickness in relation to impact on behaviour. The QWB, HUI and EQ-5D are preference-based measures designed to summarise HR-QOL in a single number ranging from 0 to 1. We found that there are no uniformly 'worst' or 'best' performing instruments. The decision to use one over another, to use a combination of 2 or more, to use a profile and/or a preference-based measure or to use a generic measure along with a targeted measure will be driven by the purpose of the measurement. In addition, the choice will depend on a variety of factors including the characteristics of the population (e.g. age, health status, language/culture) and the environment in which the measurement is undertaken (e.g. clinical trial, routine physician visit). We provide our summary of the level of evidence in the literature regarding each instrument's characteristics based on the review criteria. The potential user of these instruments should base their instrument selection decision on the characteristics that are most relevant to their particular HR-QOL measurement needs.

The Arabidopsis abscisic acid response locus ABI4 encodes an APETALA 2 domain protein

Arabidopsis abscisic acid (ABA)-insensitive abi4 mutants have pleiotropic defects in seed development, including decreased sensitivity to ABA inhibition of germination and altered seed-specific gene expression. This phenotype is consistent with a role for ABI4 in regulating seed responses to ABA and/or seed-specific signals. We isolated the ABI4 gene by positional cloning and confirmed its identity by complementation analysis. The predicted protein product shows homology to a plant-specific family of transcriptional regulators characterized by a conserved DNA binding domain, the APETALA 2 domain. The single mutant allele identified has a single base pair deletion, resulting in a frameshift that should disrupt the C-terminal half of the protein but leave the presumed DNA binding domain intact. Expression analyses showed that despite the seed-specific nature of the mutant phenotype, ABI4 expression is not seed specific.

Neonatal anthropometry: the thin-fat Indian baby. The Pune Maternal Nutrition Study

OBJECTIVE

To examine body size and fat measurements of babies born in rural India and compare them with white Caucasian babies born in an industrialised country.

DESIGN

Community-based observational study in rural India, and comparison with data from an earlier study in the UK, measured using similar methods.

SUBJECTS

A total of 631 term babies born in six rural villages, near the city of Pune, Maharashtra, India, and 338 term babies born in the Princess Anne Hospital, Southampton, UK.

MEASUREMENTS

Maternal weight and height, and neonatal weight, length, head, mid-upper-arm and abdominal circumferences, subscapular and triceps skinfold thicknesses, and placental weight.

RESULTS

The Indian mothers were younger, lighter, shorter and had a lower mean body mass index (BMI) (mean age, weight, height and BMI: 21.4 y, 44.6 kg, 1.52 m, and 18.2 kg/m(2)) than Southampton mothers (26.8 y, 63.6 kg, 1.63 m and 23.4 kg/m(2)). They gave birth to lighter babies (mean birthweight: 2.7 kg compared with 3.5 kg). Compared to Southampton babies, the Indian babies were small in all body measurements, the smallest being abdominal circumference (s.d. score: -2.38; 95% CI: -2.48 to -2.29) and mid-arm circumference (s.d. score: -1.82; 95% CI: -1.89 to -1.75), while the most preserved measurement was the subscapular skinfold thickness (s.d. score: -0.53; 95% CI: -0.61 to -0.46). Skinfolds were relatively preserved in the lightest babies (below the 10th percentile of birthweight) in both populations.

CONCLUSIONS

Small Indian babies have small abdominal viscera and low muscle mass, but preserve body fat during their intrauterine development. This body composition may persist postnatally and predispose to an insulin-resistant state.

Relation of angiographically defined coronary artery disease to plasma lipoprotein subfractions and apolipoproteins

The relation of coronary artery disease to plasma lipoproteins was examined in 104 men aged 35-65 years undergoing coronary angiography for suspected myocardial ischaemia. A score reflecting the number, degree, and length of stenoses in seven major coronary arteries was assigned to each angiogram. Lipid concentrations in lipoprotein subfractions were measured after preparative ultracentrifugation; plasma apolipoprotein concentrations were measured by electroimmunoassay. Men with high coronary scores tended to have lower plasma high-density lipoprotein (HDL) cholesterol concentrations and higher low-density lipoprotein (density 1.019-1.063 g/ml) cholesterol concentrations than subjects of similar age with low coronary scores (p approximately equal to 0.1). The strongest relation, however, was with the cholesterol concentration in the HDL2 subfraction (density 1.063-1.125 g/ml) of HDL, which averaged 44% lower in the severely affected patients (p less than 0.005). No associations were found between the coronary score and HDL3 cholesterol, the cholesterol content of lipoproteins of density less than 1.019 g/ml, plasma triglyceride, or the concentrations of apolipoproteins AI, AII, and E. The high coronary scores associated with low HDL2 concentrations reflected an increase in the number of both partial and complete stenoses distributed throughout the coronary tree. In contrast the sizes of the lesions and the proportion producing complete occlusion were unrelated to HDL2.

Preferential Zn2+ influx through Ca2+-permeable AMPA/kainate channels triggers prolonged mitochondrial superoxide production

Synaptically released Zn2+ can enter and cause injury to postsynaptic neurons. Microfluorimetric studies using the Zn2+-sensitive probe, Newport green, examined levels of [Zn2+]i attained in cultured cortical neurons on exposure to N-methyl-D-asparte, kainate, or high K+ (to activate voltage-sensitive Ca2+ channels) in the presence of 300 microM Zn2+. Indicating particularly high permeability through Ca2+-permeable alpha-amino3-hydroxy-5-methyl-4-isoxazolepropionic-acid/kainate (Ca-A/K) channels, micromolar [Zn2+]i rises were observed only after kainate exposures and only in neurons expressing these channels [Ca-A/K(+) neurons]. Further studies using the oxidation-sensitive dye, hydroethidine, revealed Zn2+-dependent reactive oxygen species (ROS) generation that paralleled the [Zn2+]i rises, with rapid oxidation observed only in the case of Zn2+ entry through Ca-A/K channels. Indicating a mitochondrial source of this ROS generation, hydroethidine oxidation was inhibited by the mitochondrial electron transport blocker, rotenone. Additional evidence for a direct interaction between Zn2+ and mitochondria was provided by the observation that the Zn2+ entry through Ca-A/K channels triggered rapid mitochondrial depolarization, as assessed by using the potential-sensitive dye tetramethylrhodamine ethylester. Whereas Ca2+ influx through Ca-A/K channels also triggers ROS production, the [Zn2+]i rises and subsequent ROS production are of more prolonged duration.

Intake of micronutrient-rich foods in rural Indian mothers is associated with the size of their babies at birth: Pune Maternal Nutrition Study

One third of the Indian babies are of low birth weight (<2.5 kg), and this is attributed to maternal undernutrition. We therefore examined the relationship between maternal nutrition and birth size in a prospective study of 797 rural Indian women, focusing on macronutrient intakes, dietary quality and micronutrient status. Maternal intakes (24-h recall and food frequency questionnaire) and erythrocyte folate, serum ferritin and vitamin C concentrations were measured at 18 +/- 2 and 28 +/- 2 wk gestation. Mothers were short (151.9 +/- 5.1 cm) and underweight (41.7 +/- 5.1 kg) and had low energy and protein intakes at 18 wk (7.4 +/- 2.1 MJ and 45.4 +/- 14.1 g) and 28 wk (7.0 +/- 2.0 MJ and 43.5 +/- 13.5 g) of gestation. Mean birth weight and length of term babies were also low (2665 +/- 358 g and 47.8 +/- 2.0 cm, respectively). Energy and protein intakes were not associated with birth size, but higher fat intake at wk 18 was associated with neonatal length (P < 0.001), birth weight (P < 0.05) and triceps skinfold thickness (P < 0.05) when adjusted for sex, parity and gestation. However, birth size was strongly associated with the consumption of milk at wk 18 (P < 0.05) and of green leafy vegetables (P < 0.001) and fruits (P < 0.01) at wk 28 of gestation even after adjustment for potentially confounding variables. Erythrocyte folate at 28 wk gestation was positively associated with birth weight (P < 0.001). The lack of association between size at birth and maternal energy and protein intake but strong associations with folate status and with intakes of foods rich in micronutrients suggest that micronutrients may be important limiting factors for fetal growth in this undernourished community.

An HIV-1 transgenic rat that develops HIV-related pathology and immunologic dysfunction

We report, to our knowledge, the first HIV type 1 (HIV-1) transgenic (Tg) rat. Expression of the transgene, consisting of an HIV-1 provirus with a functional deletion of gag and pol, is regulated by the viral long terminal repeat. Spliced and unspliced viral transcripts were expressed in lymph nodes, thymus, liver, kidney, and spleen, suggesting that Tat and Rev are functional. Viral proteins were identified in spleen tissue sections by immunohistochemistry and gp120 was present in splenic macrophages, T and B cells, and in serum. Clinical signs included wasting, mild to severe skin lesions, opaque cataracts, neurological signs, and respiratory difficulty. Histopathology included a selective loss of splenocytes within the periarterial lymphoid sheath, increased apoptosis of endothelial cells and splenocytes, follicular hyperplasia of the spleen, lymphocyte depletion of mesenteric lymph nodes, interstitial pneumonia, psoriatic skin lesions, and neurological, cardiac, and renal pathologies. Immunologically, delayed-type hypersensitivity response to keyhole limpet hemocyanin was diminished. By contrast, Ab titers and proliferative response to recall antigen (keyhole limpet hemocyanin) were normal. The HIV-1 Tg rat thus has many similarities to humans infected with HIV-1 in expression of viral genes, immune-response alterations, and pathologies resulting from infection. The HIV-1 Tg rat may provide a valuable model for some of the pathogenic manifestations of chronic HIV-1 diseases and could be useful in testing therapeutic regimens targeted to stages of viral replication subsequent to proviral integration.

Lovastatin-mediated G1 arrest is through inhibition of the proteasome, independent of hydroxymethyl glutaryl-CoA reductase

In this paper we present the finding that lovastatin arrests cells by inhibiting the proteasome, which results in the accumulation of p21 and p27, leading to G1 arrest. Lovastatin is an inhibitor of hydroxymethyl glutaryl (HMG)-CoA reductase, the rate-limiting enzyme in cholesterol synthesis. Previously, we reported that lovastatin can be used to arrest cultured cells in the G1 phase of the cell cycle, resulting in the stabilization of the cyclin-dependent kinase inhibitors (CKIs) p21 and p27. In this report we show that this stabilization of p21 and p27 may be the result of a previously unknown function of the pro-drug, beta-lactone ring form of lovastatin to inhibit the proteasome degradation of these CKIs. The lovastatin mixture used in this study is 80% open-ring form and 20% pro-drug, beta-lactone form. We show that while the lovastatin open-ring form and pravastatin (a lovastatin analogue, 100% open ring) inhibit the HMG-CoA reductase enzyme, lovastatin pro-drug inhibits the proteasome but does not inhibit HMG-CoA reductase. In addition, many of the properties of proteasome inhibition by the pro-drug are the same as the specific proteasome inhibitor lactacystin. Lastly, mevalonate (used to rescue cells from lovastatin arrest) unexpectedly abrogates the lactacystin and lovastatin pro-drug inhibition of the proteasome. Mevalonate increases the activity of the proteasome, which results in degradation of the CKIs, allowing lovastatin- and lactacystin-arrested cells to resume cell division. The lovastatin-mediated inhibition of the proteasome suggests a unique mechanism for the chemopreventative effects of this agent seen in human cancer.

Multicenter phase II trial of temozolomide in patients with glioblastoma multiforme at first relapse

BACKGROUND

Recurrent glioblastoma multiforme (GBM) is resistant to most therapeutic endeavors, with low response rates and survival rarely exceeding six months. There are no clearly established chemotherapeutic regimens and the aim of treatment is palliation with improvement in the quality of life.

PATIENTS AND METHODS

We report an open-label, uncontrolled, multicenter phase II trial of temozolomide in 138 patients (intent-to-treat [ITT] population) with glioblastoma multiforme at first relapse and a Karnofsky performance status (KPS) > or = 70. One hundred twenty-eight patients were histologically confirmed with GBM or gliosarcoma (GS) by independent central review. Chemotherapy-naïve patients were treated with temozolomide 200 mg/m2/day orally for the first five days of a 28-day cycle. Patients previously treated with nitrosourea-containing adjuvant chemotherapy received 150 mg/m2/day for the first five days of a 28-day cycle. In the absence of grade 3 or 4 toxicity, patients on the 150 mg/m2 dose schedule were eligible for a 200 mg/m2 dose on the next cycle.

RESULTS

The primary endpoint was six-month progression-free survival assessed with strict radiological and clinical criteria. Secondary endpoints included radiological response and Health-related Quality of Life (HQL). Progression-free survival at six months was 18% (95% confidence interval (CI): 11%-26%) for the eligible-histology population. Median progression-free survival and median overall survival were 2.1 months and 5.4 months, respectively. The six-month survival rate was 46%. The objective response rate (complete response and partial response) determined by independent central review of gadolinium-enhanced magnetic resonance imaging (MRI) scans was 8% for both the ITT and eligible-histology populations, with an additional 43% and 45% of patients, respectively, having stable disease (SD). Objectively assessed response and maintenance of a progression-free status were both associated with HQL benefits (characterized by improvements over baseline in HQL domains). Temozolomide had an acceptable safety profile, with only 9% of therapy cycles requiring a dose reduction due to thrombocytopenia. There was no evidence of cumulative hematologic toxicity.

CONCLUSIONS

Temozolomide demonstrated modest clinical efficacy, with an acceptable safety profile and measurable improvement in quality of life in patients with recurrent GBM. The use of this drug should be explored further in an adjuvant setting and in combination with other agents.

Recommendations from the National Multiple Sclerosis Society Clinical Outcomes Assessment Task Force

This article provides recommendations from the National Multiple Sclerosis Society's Clinical Outcomes Assessment Task Force. The Task Force was appointed in 1994 and charged with recommendending improved approaches for clinical outcomes assessment in future controlled clinical trials. The recommendations herein follow extensive deliberation and data analysis during 2.5 years. General principles and desirable measurement attributes were used to assess alternative measurement techniques and clinical scales. On the basis of the analysis of existing multiple sclerosis (MS) data sets, a new measurement approach is proposed. The approach is based on quantitative functional composites that consist of simple quantitative measures from the major clinical dimensions of MS combined into a single score. Quantitative functional composites are likely to provide improved precision and sensitivity in future MS clinical trials. Studies necessary to further refine quantitative functional composites as useful MS clinical trial outcomes are delineated.

Long-term survival after epirubicin, cisplatin and fluorouracil for gastric cancer: results of a randomized trial

We report the final results of a prospectively randomized study that compared the combination of epirubicin, cisplatin and protracted venous infusion fluorouracil (5-FU) (ECF regimen) with the standard combination of 5-FU, doxorubicin and methotrexate (FAMTX) in previously untreated patients with advanced oesophagogastric cancer. Between 1992 and 1995, 274 patients with adenocarcinoma or undifferentiated carcinoma were randomized from eight oncology centres in the UK and analysed for response and survival. The overall response rate was 46% (95% confidence interval (CI), 37-55%) with ECF, and 21% (95% CI, 13-28%) with FAMTX (P = 0.00003). The median survival was 8.7 months with ECF and 6.1 months with FAMTX (P = 0.0005). The 2-year survival rates were 14% (95% CI, 8-20%) for the ECF arm, and 5% (95% CI, 2-10%) for the FAMTX arm (P = 0.03). Histologically complete surgical resection following chemotherapy was achieved in ten patients in the ECF arm (three pathological complete responses to chemotherapy) and three patients in the FAMTX arm (no pathological complete responses). The ECF regimen resulted in a response and survival advantage compared with FAMTX chemotherapy. The probability of long-term survival following surgical resection of residual disease is increased by this treatment. The high response rates seen with ECF support its use in the neoadjuvant setting.

Obstructive defecation: a failure of rectoanal coordination

OBJECTIVE

The pathophysiology of obstructive defecation is unclear. We investigated whether impaired rectoanal coordination causes obstructive defecation and if this dysfunction can be corrected by biofeedback therapy.

METHODS

We prospectively studied 25 healthy subjects and 35 consecutive patients with constipation (>1 year) with anorectal manometry and balloon expulsion test. Symptoms were assessed from diary cards. Patients found to have obstructive defecation were offered biofeedback therapy. After treatment, their defecation dynamics and symptoms were reassessed.

RESULTS

Eighteen patients had obstructive defecation and 17 had normal defecation dynamics (nonobstructive). Five normals (20%) exhibited obstructive pattern but only one failed to expel balloon. In the obstructive group, during straining, the intrarectal pressure and defecation index were lower (p < 0.05), and anal residual pressure was higher (p < 0.01) when compared with the nonobstructive group or normals. After biofeedback therapy, the intrarectal pressure and defecation index increased (p < 0.02) and anal residual pressure decreased (p < 0.001); stool frequency, degree of straining, and bowel satisfaction scores improved (p < 0.05); 67% stopped laxatives and 11 patients discontinued stooling with digitation.

CONCLUSION

Patients with obstructive defecation showed impaired rectal contraction, paradoxical anal contraction, or inadequate anal relaxation. These features suggest that rectoanal coordination was impaired. Biofeedback therapy rectified these pathophysiological disturbances and improved constipation.

Body mass index as a predictor of hepatic steatosis in living liver donors

Evaluation of the living donor for liver transplantation is a complex process involving such invasive studies as liver biopsy and angiography. It is important to establish the likelihood and extent of hepatic steatosis in living donors by clinical, imaging, and biochemical parameters to avoid performing a liver biopsy, if possible. In this study, the predictive value of body mass index (BMI), liver chemistry tests, and imaging studies was compared with liver histological examination in 33 potential living donors. Patients were grouped and compared based on their BMI (<25, 25 to 28, >28). No patient with a BMI less than 25 had hepatic steatosis. Of patients with a BMI of 25 to 28, steatosis was found on biopsy in 3 of 9 patients. Thirteen of 17 patients (76%) with a BMI greater than 28 had hepatic steatosis on liver biopsy. There was a significant correlation between BMI and overall grade of steatosis (R = 0.49). All subjects with steatosis detected on magnetic resonance imaging (MRI) or computed tomography (CT) had steatosis on biopsy, and all but 2 such patients had greater than 10% steatosis on biopsy. Conversely, 30% of patients in the MRI group and 24% of patients in the CT group failed to show hepatic steatosis when it was present on biopsy. Thus, it appears that liver biopsy could be avoided in subjects with a normal BMI and absence of risk factors. Individuals with a high BMI should undergo liver biopsy because biochemical and imaging data are currently inadequate to determine the extent of steatosis. Future studies should aim at improving the sensitivity of imaging techniques in the diagnosis of steatosis.

Manometric tests of anorectal function in healthy adults

OBJECTIVE

Although tests of anorectal function are useful in the assessment of defecation disorders, there is inadequate and inconsistent information regarding normative data. Also, there are discrepancies in manometric techniques and data interpretation. Our aim was to perform a comprehensive evaluation of anorectal function in healthy adults.

METHODS

We used a 6-mm diameter probe containing six radially arrayed microtransducers, and a 4-cm-long latex balloon for performing anorectal manometry in 45 healthy subjects who were controlled for gender and age. Sequentially, subjects were asked to squeeze, bear down, or blow up a party balloon. Subsequently, rectal sensation, rectal compliance, and rectoanal reflexes were assessed simultaneously by performing intermittent phasic balloon distentions. Additionally, balloon defecation, pudendal nerve latency, and saline continence tests were performed.

RESULTS

In men, the anal sphincter was longer (p < 0.05) and squeeze sphincter pressure and squeeze duration were higher (p < 0.01), but resting sphincter pressure was similar to that in women. When bearing down, although not significant, the defecation index was higher in men. Distinct thresholds for rectal sensation were identified but there was no gender difference. Likewise, rectal compliance and balloon expulsion time were similar. However, during saline infusion, the onset of first leak and total volume retained were higher (p < 0.001) and pudendal nerve latency was shorter (p < 0.05) in men. Overall, parity or age did not influence anorectal function.

CONCLUSIONS

This study represents the most comprehensive age- and gender-controlled assessment of anorectal function using solid state technology. Gender influences some parameters of anorectal function. Our results could serve as a valuable resource of normative data.

Phase III double-blind placebo-controlled study of farnesyl transferase inhibitor R115777 in patients with refractory advanced colorectal cancer

PURPOSE

To determine whether R115777 improves survival in patients with refractory advanced colorectal cancer (CRC) in a multicenter, double-blind, prospective randomized study.

PATIENTS AND METHODS

Three hundred sixty-eight patients were randomly assigned to R115777 (300 mg twice daily) orally for 21 days every 28 days or placebo in a 2:1 ratio. All patients received best supportive care. The primary end point was overall survival; secondary end points were progression free survival, tumor response, toxicity, and quality of life.

RESULTS

The two treatment groups were well balanced for baseline demographics, including previous chemotherapy for advanced CRC. The median overall survival for R115777 was 174 days (95% CI, 157 to 198 days), and 185 days (95% CI, 158 to 238 days) for those patients receiving placebo (P =.376). One patient achieved a partial response in the R115777 arm. Stable disease (> 3 months) was observed in 24.3% patients in the R115777 group compared to 12.8% in the placebo arm. This did not translate into a statistically significant increase in progression-free survival. Overall, treatment was well tolerated. There was an increased incidence of reversible myelosuppression (neutropenia, thrombocytopenia), rash, and grade 1 to 2 diarrhea in the R115777 arm. There was no statistically significant difference in quality of life between arms.

CONCLUSION

Single agent R115777, given at this dose and schedule, has an acceptable toxicity profile, but does not improve overall survival compared to best supportive care alone in refractory advanced CRC.

Chromatin remodeling, measured by a novel real-time polymerase chain reaction assay, across the proximal promoter region of the IL-2 gene

The structure of chromatin and its remodeling following activation are important aspects of the control of inducible gene transcription. The IL-2 gene is induced in a cell specific-manner in T cells following an antigenic stimulus. We show, using a novel real-time PCR assay, that significant chromatin remodeling of the IL-2 proximal promoter region occurred upon stimulation of both the murine EL-4 T cell line and primary CD4(+) T cells. Chromatin remodeling appears to be limited to the first 300 bp of the proximal promoter region as measured by micrococcal nuclease and restriction enzyme accessibility. Time course studies indicated that chromatin remodeling was observed at 1.5 h postinduction and was maintained for up to 16 h. The remodeling is reversible upon removal of the stimulus. The region immediately upstream from the transcription start site, however, remains accessible for up to 16 h. Upon restimulation, remodeling occurs much more rapidly, consistent with a more rapid rise in IL-2 mRNA levels. Using a number of pharmacological inhibitors we show that remodeling is dependent on the presence of specific transcription factors, but not on the modification of histones. The development of this novel chromatin accessibility assay based on real-time PCR has allowed rapid, sensitive, and quantitative measurements on the IL-2 gene following cellular activation in both T cell lines and primary cells.

Ambulatory 24-h colonic manometry in healthy humans

Our aim was to investigate motor activity of the healthy, relatively unprepared colon in the ambulatory state. Twenty-five age- and gender-matched adults had a six-sensor solid-state probe inserted into the proximal transverse colon without sedation. Subjects ambulated freely and ate standard meals. In 528 h of recording, we found a lower (P < 0.05) area under the curve during the night. Waking induced a threefold increase in motility, whereas meals induced a twofold increase. Women showed less activity (P < 0.05) in the transverse/descending colon than men. The transverse/descending colon showed more (P < 0.05) activity than the rectosigmoid colon. Seven patterns were recognized; predominantly, they were simultaneous, propagated, or periodic bursts of 3-cycles/min (cpm) waves. A specialized propagating pressure wave with a high amplitude (>105 mmHg) and a prolonged duration (>14 s) occurred in all subjects (mean 10/day), mostly after waking, after meals, or with defecation. A 3-cpm motor activity was seen in the rectosigmoid region predominantly at night. The colon exhibits a wide spectrum of pressure activity around the clock, with gender and regional differences and circadian rhythm. This comprehensive study provides qualitative and quantitative normative data for colonic manometry.

American Neurogastroenterology and Motility Society consensus statement on intraluminal measurement of gastrointestinal and colonic motility in clinical practice

Tests of gastric, small intestinal and colonic motor function provide relevant physiological information and are useful for diagnosing and guiding the management of dysmotilities. Intraluminal pressure measurements may include concurrent measurements of transit or intraluminal pH. A consensus statement was developed and based on reports in the literature, experience of the authors, and discussions conducted under the auspices of the American Neurogastroenterology and Motility Society in 2008. The article reviews the indications, methods, performance characteristics, and clinical utility of intraluminal measurements of pressure activity and tone in the stomach, small bowel and colon in humans. Gastric and small bowel motor function can be measured by intraluminal manometry, which may identify patterns suggestive of myopathy, neuropathy, or obstruction. Manometry may be most helpful when it is normal. Combined wireless pressure and pH capsules provide information on the amplitude of contractions as they traverse the stomach and small intestine. In the colon, manometry assesses colonic phasic pressure activity while a barostat assesses tone, compliance, and phasic pressure activity. The utility of colonic pressure measurements by a single sensor in wireless pressure/pH capsules is not established. In children with intractable constipation, colonic phasic pressure measurements can identify patterns suggestive of neuropathy and predict success of antegrade enemas via cecostomy. In adults, these assessments may be used to document severe motor dysfunction (colonic inertia) prior to colectomy. Thus, intraluminal pressure measurements may contribute to the management of patients with disorders of gastrointestinal and colonic motility.

Analysis and phylogenetic comparisons of full-length VP2 genes of the 24 bluetongue virus serotypes

The outer capsid protein VP2 of Bluetongue virus (BTV) is a target for the protective immune response generated by the mammalian host. VP2 contains the majority of epitopes that are recognized by neutralizing antibodies and is therefore also the primary determinant of BTV serotype. Full-length cDNA copies of genome segment 2 (Seg-2, which encodes VP2) from the reference strains of each of the 24 BTV serotypes were synthesized, cloned and sequenced. This represents the first complete set of full-length BTV VP2 genes (from the 24 serotypes) that has been analysed. Each Seg-2 has a single open reading frame, with short inverted repeats adjacent to conserved terminal hexanucleotide sequences. These data demonstrated overall inter-serotype variations in Seg-2 of 29 % (BTV-8 and BTV-18) to 59 % (BTV-16 and BTV-22), while the deduced amino acid sequence of VP2 varied from 22.4 % (BTV-4 and BTV-20) to 73 % (BTV-6 and BTV-22). Ten distinct Seg-2 lineages (nucleotypes) were detected, with greatest sequence similarities between those serotypes that had previously been reported as serologically ‘related’. Fewer similarities were observed between different serotypes in regions of VP2 that have been reported as antigenically important, suggesting that they may play a role in the neutralizing antibody response. The data presented form an initial basis for BTV serotype identification by sequence analyses and comparison of Seg-2, and for development of molecular diagnostic assays for individual BTV serotypes (by RT-PCR).

Erythropoiesis-stimulating agents in oncology: a study-level meta-analysis of survival and other safety outcomes

BACKGROUND: Cancer patients often develop the potentially debilitating condition of anaemia. Numerous controlled studies indicate that erythropoiesis-stimulating agents (ESAs) can raise haemoglobin levels and reduce transfusion requirements in anaemic cancer patients receiving chemotherapy. To evaluate recent safety concerns regarding ESAs, we carried out a meta-analysis of controlled ESA oncology trials to examine whether ESA use affects survival, disease progression and risk of venous-thromboembolic events.

METHODS: This meta-analysis included studies from the 2006 Cochrane meta-analysis, studies published/updated since the 2006 Cochrane report, and unpublished trial data from Amgen and Centocor Ortho Biotech. The 60 studies analysed (15 323 patients) were conducted in the settings of chemotherapy/radiochemotherapy, radiotherapy only treatment or anaemia of cancer. Data were summarised using odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS: Results indicated that ESA use did not significantly affect mortality (60 studies: OR=1.06; 95% CI: 0.97–1.15) or disease progression (26 studies: OR=1.01; 95% CI: 0.90–1.14), but increased the risk for venous-thromoboembolic events (44 studies: OR=1.48; 95% CI: 1.28–1.72).

CONCLUSION: Though this meta-analysis showed no significant effect of ESAs on survival or disease progression, prospectively designed, future randomised clinical trials will further examine the safety and efficacy of ESAs when used according to the revised labelling information.

Perceptual dimensions of tactile surface texture: a multidimensional scaling analysis

The purpose of this study was to examine the subjective dimensionality of tactile surface texture perception. Seventeen tactile stimuli, such as wood, sandpaper, and velvet, were moved across the index finger of the subject, who sorted them into categories on the basis of perceived similarity. Multidimensional scaling (MDS) techniques were then used to position the stimuli in a perceptual space on the basis of combined data of 20 subjects. A three-dimensional space was judged to give a satisfactory representation of the data. Subjects' ratings of each stimulus on five scales representing putative dimensions of perceived surface texture were then fitted by regression analysis into the MDS space. Roughness-smoothness and hardness-softness were found to be robust and orthogonal dimensions; the third dimension did not correspond closely with any of the rating scales used, but post hoc inspection of the data suggested that it may reflect the compressional elasticity ("springiness") of the surface.

Sensitivity of conventional memory tests in multiple sclerosis: comparing the Rao Brief Repeatable Neuropsychological Battery and the Minimal Assessment of Cognitive Function in MS

BACKGROUND

Cognitive impairment is common in multiple sclerosis (MS) affecting roughly 45-60% of patients. Because memory deficits have significant impact on employment, caregiver burden, and social functioning, neuropsychological (NP) assessment is often recommended. Two widely used and validated NP batteries for MS are the Rao Brief Repeatable Neuropsychological Battery (BRNB) and the Minimal Assessment of Cognitive Function in MS (MACFIMS). Although similar, these batteries differ in the specific auditory/verbal and visual/spatial memory tests employed. The relative sensitivity of these memory tests is unknown.

METHODS

The BRNB and MACFIMS have considerable overlap but different memory tests: the former includes the Selective Reminding Test (SRT) and the 10/36 Spatial Recall Test (10/36) and the latter the California Verbal Learning Test, Second Edition (CVLT2) and Brief Visuospatial Memory Test, Revised (BVMTR). In 65 patients with MS and 46 demographically matched controls, we compared the sensitivity of these tests, and secondarily their respective batteries.

RESULTS

The BRNB and MACFIMS were comparable in their overall sensitivity to disease status. Although the BVMTR showed greater discriminative validity than the 10/36, the CVLT2 and SRT were comparable in sensitivity. The SDMT was the most sensitive NP test across both batteries.

CONCLUSIONS

We conclude that the BRNB and MACFIMS have comparable sensitivity among patients with MS. The sensitivity of the auditory/verbal memory tests from these batteries is similar, but the BVMTR appears to be more sensitive than the 10/36. Clinical implications are discussed.

Down's syndrome: an atheroma-free model?

Postmortem examination of five institutionalised patients with Down's syndrome (DS) aged 40-66 years showed a complete absence of atheroma, while a similar number of mental defectives with DS were found to have mild or severe atheroma. Previous investigation of risk factors for atheroma in 70 patients with DS and 70 age-and sex-matched mental defectives living in the same institution showed significantly lower systolic and diastolic blood pressures in the DS group, with the exception of systolic pressure in men under 40. Fasting serum cholesterol and triglyceride concentrations were similar in the two groups, but triglyceride concentrations were significantly lower than in normal people without a history of vascular disease. These unexplained observations may be relevant in further studies of the pathogenesis of atheroma.

Proposal for pharmacologically distinct conformers of PDE4 cyclic AMP phosphodiesterases

cAMP-specific phosphodiesterase inhibitors display a range of activities in vitro and in vivo which suggest they may be useful in the treatment of inflammatory diseases. However, these compounds elicit a number of side-effects which may limit their therapeutic potential. Certain side-effects of PDE4 inhibitors such as emesis and gastric acid secretion are associated with their actions at a high affinity rolipram binding site (HARBS). In contrast, a number of anti-inflammatory actions of PDE4 inhibitors are better correlated with inhibition of PDE4 catalytic activity than with displacement of [3H] rolipram from HARBS. This suggests that native PDE4s in different cell-types can be discriminated pharmacologically. Although known to be associated with PDE4, the nature of HARBS is uncertain. The majority of evidence suggests it represents particular conformational states of PDE subtypes with which rolipram interacts with high potency (KD approximately 2 nM) (High-affinity PDE4, HPDE4). Rolipram is generally moderately or weakly active (IC50-200 nM-2000 nM) in inhibiting catalytic activity of the majority of crude, partially-purified or recombinant PDE4-preparations (Low-affinity PDE4, LPDE4). Solubilization or V/GSH treatment of particulate eosinophil PDE4, cAMP-dependent kinase activation of RNPDE4D3 and membrane association of HSPDE4A4 increase the potencies of some (e.g., rolipram) but not other (e.g., trequinsin) inhibitors. In eosinophils, the changes in enzyme properties brought about by solubilization result in a close correlation between the potency order of compounds in inhibiting cAMP hydrolysis and displacing [3H] rolipram from HARBS. The identification of distinct pharmacological PDE4 forms may have therapeutic consequences since it may be possible to synthesize potent inhibitors of LPDE4 with low affinity for HARBS which should, theoretically, be less emetic. Most inhibitors synthesized to date (rolipram, denbufylline nitraquazone, etc.) display high-affinity for HARBS but are much weaker in inhibiting cAMP hydrolysis. Other compounds (RP 73401, trequinsin, CDP 840) display slightly higher potency against LPDE4 or do not discriminate between the two putative PDE4 forms. Recently, inhibitors have been synthesized which are considerably more active against LPDE4 than HPDE4. Such compounds with appropriate pharmacokinetic properties may retain anti-inflammatory activity but have a reduced capacity to cause nausea and emesis and, consequently, have a wider therapeutic window than compounds currently undergoing clincial evaluation.