Identification of a 14 kb deletion involving the promoter region of BRCA1 in a breast cancer family

BRCA1 is a breast and ovarian cancer susceptibility gene. An inferred germline regulatory mutation was previously reported in the BRCA1-linked kindred K2035, based on the absence of transcripts from the BRCA1 allele associated with the cancer susceptibility haplotype. In this study, the promoter region of BRCA1 was examined in individuals from K2035 for evidence of a mutation which could halt transcription. Evaluation of a polymorphism located within intron 2 of BRCA1 gave results consistent with the presence of a large deletion in K2035 mutation carriers. Southern blot analysis identified unique restriction fragments which occurred as a result of a 14 kb deletion that removed both of BRCA1's transcription start sites (exons 1a and 1b) as well as exon 2. Sequencing indicated that unequal crossover between Alu repeats was the likely cause of the deletion. Similar deletions may be responsible for other reported inferred regulatory mutations, as well as unidentified mutations in families linked to BRCA1.

Recessive inheritance of obesity in familial non-insulin-dependent diabetes mellitus, and lack of linkage to nine candidate genes

Segregation analysis of body-mass index (BMI) supported recessive inheritance of obesity, in pedigrees ascertained through siblings with non-insulin dependent diabetes mellitus (NIDDM). BMI was estimated as 39 kg/m2 for those subjects homozygous at the inferred locus. Two-locus segregation analysis provided weak support for a second recessive locus, with BMI estimated as 32 kg/m2 for homozygotes. NIDDM prevalence was increased among those subjects presumed to be homozygous at either locus. Using both parametric and nonparametric methods, we found no evidence of linkage of obesity to any of nine candidate genes/regions, including the Prader-Willi chromosomal region (PWS), the human homologue of the mouse agouti gene (ASP), and the genes for leptin (OB), the leptin receptor (OBR/DB), the beta3-adrenergic receptor (ADRB3), lipoprotein lipase (LPL), hepatic lipase (LIPC), glycogen synthase (GYS), and tumor necrosis factor alpha (TNFA).

CDC guidelines for infection precautions

The Centers for Disease Control and Prevention (CDC) has revised its infection control recommendations for health care organizations and their staffs. Although the CDC guidelines are not home care specific, providers can use these precautions in most health care delivery sites, including in-home services.

Stability of refrigerated and frozen solutions of tropisetron in either polyvinylchloride or polyolefin infusion bags

OBJECTIVE

To investigate the stability of 50 microg/ml tropisetron in 0.9% sodium chloride or 5% dextrose injections on storage in either 100 ml polyvinylchloride (Tuliflex) or polyolefin (Clear-flex) infusion bags, at +4 degrees C and -20 degrees C.

METHOD

A stability-indicating high-performance liquid chromatography (HPLC) assay was used to measure residual drug at day 0 (D0), D8, D15, D30, D60 and D90 for each bag. Samples were tested for pH at D0, D60 and D90. Frozen samples were thawed in a microwave oven according to a validated procedure before analysis.

RESULTS

In 0.9% sodium chloride and 5% dextrose, no degradation products were observed in any of the chromatograms. No admixtures, at any time, contained less than 98.2% of the initial concentration. Only minor changes (-0.12 unit) in pH occurred over the storage period. No colour or other visual changes were seen in any sample.

CONCLUSION

Tropisetron (50 microg/ml) in either 0.9% sodium chloride or 5% dextrose is chemically stable in polyvinylchloride or polyolefin bags for at least 3 months when stored in a refrigerator or in a frozen state.

Women's health status and use of health services in a rapidly growing peri-urban area of South Africa

Women's health in South Africa and particularly women living in peri-urban areas is being influenced by three major factors. These include the political transition that is occurring in the country, urbanization and the international interest in women's health. Changes in the delivery of health care to the population, and in particular to women are being planned. It is therefore important that data are available for the purpose of planning and evaluation of health services. This paper describes a household survey in which 661 women were interviewed. Socio-demographic patterns of women living in a rapidly urbanizing area were determined and related to health status, use of health services and knowledge of the services. Poverty appeared to be an overriding factor affecting the health of the population. One third of the women were living in unserviced shacks. There was a high rate of unemployment and those who were employed worked in low status jobs and earned very little. Rates of reported acute and chronic illness were lower than described elsewhere in similar household interview surveys. A third of the acute illnesses were due to respiratory disease. Reported rates of diabetes and hypertension were low indicating undiagnosed disease in the area. Being a member of an alliance household-a mixture of family, friends and lodgers-was the main predictor of acute illness. For chronic disease, age and increasing educational status were the main predictors. Knowledge of services apart from those for cervical cancer screening was good. The latter improved with increasing education, urbanization and being a member of an alliance household. As many of the women lived in unserviced areas and had little or no income the provision of infrastructural services and development programs are essential if their health is to be improved. The existing health services need to be developed to provide a comprehensive primary care service with special attention being paid to the health of women. The service should be close to their homes and be affordable. The information gathered in this survey will be used to plan services for women in the area and will act as baseline data for evaluation.

Sleep benefit in Parkinson's disease

Sleep benefit (SB) In Parkinson's disease (PD) is not well characterized. To determine SB frequency, as well as to characterize and correlate it with other disease variables, we evaluated prospectively a consecutive series of 312 PD patients by means of a structured questionnaire: 55% reported having SB and 35% reported that awakening was their best time of the day. Because of SB, 21% of the entire population were able to skip or delay medication. The mean duration of the phenomenon was 85.4 +/- 67 min. Patients with SB were significantly older (p < 0.0002), had disease longer (p < 0.05), and were often men (chi 2 = 3.5, df 1, p = 0.05). Patients with SB took sleep medication with similar frequency as those without SB. There were no differences in hours of sleep or sleep latency. Sleep problems such as nightmares or somnambulism, but not the number of sleep awakenings, were similar in both groups. In conclusion, SB is a frequent phenomenon, especially in men, elderly patients, and patients with longer disease duration. SB enables the morning L-dopa dose to be postponed in approximately 50% of patients.

Susceptibility of beta-hemolytic streptococci to nine antimicrobial agents among four medical centers in Salt Lake City, Utah, USA

A multicenter study was performed to evaluate the susceptibility of beta-hemolytic streptococci to nine antimicrobial agents. MICs were performed in cation-supplemented Mueller-Hinton broth with 3.5% lysed sheep red blood cells according to NCCLS guidelines. A total of 646 isolates were tested: 300 (46%) group A; 170 (26%) group B; 38 (6%) group C, 35 (5%) group F; 83 (17%) group G; and 20 (3%) nongroupable. Six percent of the total isolates were resistant to one or more of the antibiotics tested. Approximately 7% of 387 strains from the University of Utah Hospital and Clinics were resistant to erythromycin. Four isolates were resistant to clindamycin. Six strains (3%) from Primary Children's Medical Center (207 tested) were resistant to one or more of the macrolides. Resistance was rare at the LDS Hospital and the Salt Lake Veteran's Affairs Hospital. Overall, resistance among beta-hemolytic streptococci in this geographic location does not seem to be a significant problem, except at the tertiary care university hospital.

A case control study of breast cancer risk and exposure to injectable progestogen contraceptives. Methods and patterns of use among controls

OBJECTIVE

To describe the patterns of use of injectable progestogen contraceptives (IPCs) among coloured and black women in the Western Cape. These data are part of an ongoing study in the Western Cape, the main aim of which is to explore the relationship between IPCs and breast cancer.

DESIGN

A population-based case-control study of breast cancer risk in relation to the use of IPCs among coloured and black women.

SETTING

The Western Cape, including the Cape metropole and surrounding rural areas.

STUDY SUBJECTS

All coloured and black women with newly diagnosed breast cancer, resident in the study area and below age 55 years, who present at either of the two tertiary care hospitals in the Western Cape are recruited. Controls are a sample of hospitalised patients representative of the populations from which the patients are drawn. Cases are frequency-matched to controls according to cross-tabulation of age, ethnic group and residential area in a ratio of approximately 1:3.

MEASUREMENTS

Questionnaires are administered by trained nurse interviewers, information is elicited on a wide range of variables, including sociodemographic variables, medical history, family history of breast disease, lifetime history of all methods of contraception and use of non-contraceptive female steroids, reproductive variables, cigarette smoking, alcohol consumption and other potentially confounding variables.

RESULTS

Between January and December 1994, 122 incident cases and 389 controls were enrolled. Ever-use of IPCs among the controls was 72% (N = 280) and use for 5 years or more was 30% (N = 117). Use of IPCs in the distant past was common, with 61% (N = 232) of all controls having initiated use 10 or more years previously. Current use was also high (19%). Other contraceptive methods were used far less commonly.

CONCLUSION

Coloured and black women in South Africa have been using and continue to use IPCs for more commonly and for longer periods than women anywhere else in the world. It is therefore especially important to evaluate the risk of breast cancer and other health effects of IPCs. The rates of use identified in this study ensure that there will be adequate statistical power to evaluate long-term use, use in the distant past and current use of IPCs.

[Selection of resistance mutants and bacteriostatic and bactericidal activity of meropenem and imipenem against Acinetobacter spp]

BACKGROUND

To evaluate the inhibitory and bactericidal activity of meropenem and imipenem against multiresistant isolates of Acinetobacter spp and to compare the frequency of mutation for both antibiotics.

METHODS

Minimum inhibitory concentrations were determined by the agar dilution method. Bactericidal activities were evaluated by killing curves method employing 8 times the MIC. One-step resistant mutant selection was performed by spreading more than 5 x 10(8) ufc/ml on agar Mueller Hinton plates containing 2, 4 and 8 times the MIC of meropenem or imipenem.

RESULTS

In the group of sensitive strains (MIC < 4 mg/l for imipenem and meropenem) we detected lower MIC for imipenem than meropenem (61.5% of the strains). Strains with reduced susceptibility to imipenem (MIC = 4 mg/l) were more sensitive to meropenem with MICs equivalents to the sensitive group. Bactericidal activity was detected in 6 hs for imipenem and in 24 hs for meropenem. Meropenem was bactericidal in 4 clinical isolates with MICs = 4 mg/l for imipenem and imipenem was bactericidal in laboratory mutants resistant to meropenem. It was no possible to select mutants resistant to imipenem but for meropenem the rate of mutation was 1.4 x 10(-9) to 1.0 x 10(-8). Mutants resistant to meropenem were susceptible to imipenem and 57% of them were stable.

CONCLUSIONS

From the laboratory point of view we consider that imipenem is more active than meropenem because it presents lower MICs, better bactericidal activity, and no risk to select resistance. However meropenem could be useful in some strains resistant to imipenem (MIC = 4 mg/l). Cross-resistance was no detected so we consider that both antibiotics should be tested against Acinetobacter spp. because they are not equivalents.

The antihypertensive effect of orally administered nifedipine-loaded nanoparticles in spontaneously hypertensive rats

1. The therapeutic use of nifedipine is limited by the rapidity of the onset of its action and its short biological half-life. In order to produce a form devoid of these disadvantages we made nanoparticles of nifedipine from three different polymers, poly-epsilon-caprolactone (PCL), polylactic and glycolic acid (1:1) copolymers (PLAGA), and Eudragit RL/RS (Eudragit). Nifedipine in polyethylene glycol 400 (PEG) solution was used as a control. 2. The average diameters of the nanoparticles ranged from 0.12 to 0.21 micron; the encapsulation ratio was 82% to 88%. 3. In spontaneously hypertensive rats (SHR), the initial rapid fall in systolic arterial blood pressure following oral administration of nifedipine in PEG solution (from 193 +/- 3 to 102 +/- 2 mmHg) was not seen following administration of the same dose in Eudragit nanoparticles (from 189 +/- 2 to 156 +/- 2 mmHg); with PCL and PLAGA nanoparticles the initial fall in blood pressure was significantly reduced (nadirs PCL 124 +/- 2 and PLAGA 113 +/- 2 mmHg). Ten hours following administration, blood pressure in rats administered the nifedipine/PEG preparation had returned to normal (183 +/- 3 mmHg) whereas that of animals given nifedipine in nanoparticles (PCL 170 +/- 3, PLAGA 168 +/- 2, Eudragit 160 +/- 3 mmHg) was still significantly reduced. 4. All of the nanoparticle dosage forms decreased Cmax and increased Tmax and the mean residence time (MRT) values. Relative bioavailability was significantly increased with Eudragit nanoparticles compared to the nifedipine/PEG solution. 5. There was an inverse linear correlation between the fall in blood pressure and plasma nifedipine concentration with all preparations. 6. The nanoparticle nifedipine preparations represent sustained release forms with increased bioavailability, a less pronounced initial antihypertensive effect and a long-lasting action.

Role of the beta 3-adrenergic receptor locus in obesity and noninsulin-dependent diabetes among members of Caucasian families with a diabetic sibling pair

Obesity and insulin resistance are important risk factors for the development of noninsulin-dependent diabetes (NIDDM) and are prevalent among predisposed first degree relatives of diabetic individuals. Recent molecular screening and analysis of a common missense mutation of the beta 3-adrenergic receptor gene suggested this locus as a strong candidate for increased obesity, earlier age of diabetes onset, and insulin resistance. To test the hypothesis that the beta 3-adrenergic receptor locus affects diabetes susceptibility, obesity as measured by body mass index, and components of the insulin resistance syndrome, we examined the role of this region in families ascertained for two or more NIDDM siblings. Linkage analysis was conducted using both parametric and nonparametric analyses, including multipoint sibling pair analysis. We found no evidence for linkage to NIDDM as a dichotomous trait and no evidence for linkage to body mass index, waist/hip ratio, insulin levels, or glucose levels as quantitative traits or to reported age of onset among NIDDM individuals. The Trp64 Arg missense mutation was present in 11% of the population. The mutation was not associated with NIDDM, and Arg64 carriers did not have earlier NIDDM onset, higher body mass index, or higher waist/hip ratio than Trp64 homozygotes. Among relatives, Arg64 carriers had significantly lower fasting glucose levels and lower waist/hip ratios than Trp64 homozygotes, but no characteristics of the insulin resistance syndrome. We conclude that the beta 3-adrenergic receptor locus does not play an important role in NIDDM susceptibility or in the insulin resistance syndrome among members of families with a strong predisposition to NIDDM.

[Bactericide activity of sulbactam before bacteria belonging to the Acinetobacter calcoaceticus-Acinetobacter baumannii complex]

BACKGROUND

To evaluate the bactericidal activity of colistin, imipenem and sulbactam against 24 Acinetobacter calcoaceticus-Acinetobacter baumannii complex isolations.

METHODS

Bactericidal activity was estimated by using killing curves method. The concentrations employed were: colistin 4 mg/l, imipenem 8 mg/l and sulbactam 8 and 32 mg/l.

RESULTS

Colistin was bactericidal in 24 isolations after 6 hours of incubation. When we used 8 mg/l of imipenem we detected bactericidal activity at the susceptible strains (MIC < or = 4 mg/l). We found bactericidal effect in 15 of 18 strains susceptible to sulbactam when we used 8 mg/l in killing curves after 24 hours of incubation. Using 32 mg/l we detected the same effect in 18 strains with MIC < or = 8 mg/l.

CONCLUSIONS

Considering the high incidence of resistance in Acinetobacter spp. to several antibiotics including imipenem, we consider that sulbactam could be an excellent therapeutic alternative because it presents bactericidal activity in susceptible strains.

Stability study of nanoparticles of poly(epsilon-caprolactone), poly(D,L-lactide) and poly(D,L-lactide-co-glycolide)

The objective was to evaluate the stability of nanoparticles prepared with poly(epsilon-caprolactone), poly(D,L-lactide) and poly(D,L-lactide-co-glycolide) polymers and stored at different temperatures and in different media. The stability parameters studied were molecular weight and crystallinity of the polymer, nanoparticle size and pH. The results show that the stability of polymeric nanoparticles depends on (i) the type of polymers with the following increasing order of polymer stability: PLA25GA50 < PLA37.5GA25 < PLA50 = PCL, (ii) the storage temperature: PCL and PLA50 nanoparticles can be kept at 4 degrees C and RT during one year, while PLA37.5GA25 and PLA25GA50 nanoparticles have to be stored at 4 degrees C, and (iii) the storage conditions: buffering or freeze-drying nanoparticles improves stability.

Luminescence of ultrathin organic films: transition from monomer to excimer emission

We investigate high-quality evaporated dye layers of N, N'-dimethylperylene-3,4:9,10-bis-discarboximide of varying thicknesses, using temperature-dependent luminescence. Layers with a nominal thickness much less than a monolayer show monomer emission similar to that of dilute solutions. With increasing layer thickness, the luminescence is dominated by excimer transitions. The excimer linewidth decreases markedly with decreasing temperature. We show that the aggregation of molecules can be controlled by variation of the surface roughness.

Lack of association between early exposure to cow's milk protein and beta-cell autoimmunity. Diabetes Autoimmunity Study in the Young (DAISY)

OBJECTIVE

To examine whether infant dietary exposure to cow's milk is associated with beta-cell autoimmunity (BCA), an early predictor of insulin-dependent diabetes mellitus (IDDM).

SETTING

Denver, Colo.

DESIGN

Cross-sectional with retrospective analysis.

PARTICIPANTS

Between January 1994 and December 1995, 253 children from 171 families of persons with IDDM were screened for BCA. All children were between the ages of 9 months and 7 years.

MAIN OUTCOME MEASURES

BCA was defined as elevated levels of insulin autoantibody, glutamic acid decarboxylase autoantibody, or insulinoma-associated islet tyrosine phosphatases autoantibody (IA-2) above the 99th percentile of 198 normal subjects.

RESULTS

Eighteen cases of BCA were detected; 153 unrelated autoantibody-negative children were selected from the cohort as controls. There were no differences in the proportion of cases and controls who were exposed to cow's milk or foods containing cow's milk or to cereal, fruit and vegetable, or meat protein by 3 months or by 6 months of age. Children with BCA were breast-fed for a slightly longer duration than controls (median duration 10 vs 8 months, P=.07).

CONCLUSIONS

These data suggest that early exposure to cow's milk or other dietary protein is not associated with BCA. This calls into question the importance of cow's milk avoidance as a preventive measure for IDDM.

Isolation of degradation-deficient mutants defective in the targeting of fructose-1,6-bisphosphatase into the vacuole for degradation in Saccharomyces cerevisiae

The key regulatory enzyme in the gluconeogenesis pathway, fructose-1, 6-bisphosphatase (FBPase), is induced when Saccharomyces cerevisiae are grown in medium containing a poor carbon source. FBPase is targeted to the yeast vacuole for degradation when glucose-starved cells are replenished with fresh glucose. To identify genes involved in the FBPase degradation pathway, mutants that failed to degrade FBPase in response to glucose were isolated using a colony-blotting procedure. These vacuolar import and degradation-deficient (vid) mutants were placed into 20 complementation groups. They are distinct from the known sec, ups or pep mutants affecting protein secretion, vacuolar sorting and vacuolar proteolysis in that they sort CpY correctly and regulate osmotic pressure normally. Despite the presence of FBPase antigen in these mutants, FBPase is completely inactivated in all vid mutants, indicating that the c-AMP-dependent signal transduction pathway and inactivation must function properly in vid mutants. vid mutants block FBPase degradation by accumulating FBPase in the cytosol and also in small vesicles in the cytoplasm. FBPase may be targeted to small vesicles before uptake by the vacuole.

A functional tethered ligand thrombin receptor is present on human hematopoietic progenitor cells

The processing of inflammatory signals occurs through a variety of mechanisms; the recent descriptions of the tethered ligand receptor for thrombin (JA Hoxie et al., J Biol Chem 268:13756, and TK Vu et al., Cell 64:1057) provide a novel route and mechanism for cellular activation after inflammation and thrombosis. Using standard flow-cytometric techniques, it has been shown that the tethered ligand receptor is found on a number of terminally differentiated hematopoietic cells including platelets, lymphocytes, and monocytes. In this paper, we show that the CD34+ subset of hematopoietic stem cells bears the tethered ligand receptor on its surface; in addition, stimulation of this receptor with the agonist peptide SFLLRN results in a dose-dependent increase in intracellular calcium levels. We also show that culturing bone marrow mononuclear cells in the presence of thrombin or the tethered ligand receptor agonist peptide results in a statistically significant increase in colony-forming units-erythroid and -granulocyte/macrophage (CFU-E and CFU-GM). Although more work is needed to establish the exact mechanism of this effect, our results suggest that activation of the tethered ligand thrombin receptor may modulate the proliferative responses of CD34+ hematopoietic progenitor cells.

Newborn screening for HLA markers associated with IDDM: diabetes autoimmunity study in the young (DAISY)

Autoimmunity causing insulin-dependent diabetes mellitus (IDDM) begins in early childhood due to interactions between genes and unknown environmental factors that may be identified through follow-up of a large cohort of genetically susceptible children. Such a cohort has been established using a simple and rapid cord blood screening for HLA alleles. The DRB1 and DQB1 second exon sequences were co-amplified using the polymerase chain reaction and hybridized with single and pooled sequence-specific oligonucleotide probes. Four individual probes were used to detect the susceptibility alleles DRB1*03, DRB1*04, and DQB1*0302 as well as the usually protective DRB1*15/16 (DR2) alleles. In addition, pooled probes allow the distinction of DR3/3 from the DR3/x genotype (where x is neither DR2, 3, nor 4) and DR4/4 from DR4/x. Among 5000 newborns from the general Denver population, we have found the high-risk genotype (DRB1*03/ DRB1*04, DQB1*0302) to be present in 2.4% of non-Hispanic whites, 2.8% of Hispanics, and 1.6% of African Americans. The moderate-risk genotypes (DRB1*04, DQB1*0302/DRB1*04, DQB1*0302, DRB1*04, DQB1*0302/x, or DRB1*03/DRB1*03) are present in 17% of American non-Hispanic whites, 24% of Hispanics and in 10% of African Americans. These results demonstrate the feasibility of a large-scale newborn screening for genes associated with IDDM. The ultimate role for such a screening in future routine prediction and prevention of IDDM will depend on the availability of an effective and acceptable form of clinical intervention.

Beta-cell autoantibodies in infants and toddlers without IDDM relatives: diabetes autoimmunity study in the young (DAISY)

Little is known concerning the natural history of beta-cell autoimmunity in infants and toddlers, especially in those without a first degree IDDM relative. A population-based cohort of Colorado infants at increased IDDM risk due to their HLA genotype has been identified through a PCR-based HLA screening of cord blood and is being prospectively studied. We report the distribution of insulin (IAA), GAD65 (GAA), and ICA512 autoantibody levels in 312 children aged 9 months and in 131 children aged 15 months from this cohort, without family history of IDDM. The levels of IAA, GAA and ICA512 did not differ by the HLA genotype (DR3/4,DQB1*0302 vs. DR3/3, vs. DR2/DR4,DQB1*0302 vs. DRx/4,DQB1*0302, where x is not DR3 or DR2), by ethnicity (non-Hispanic whites vs. other ethnic groups), or by age (9 vs. 15 months). The 95th and 99th percentiles of the IAA distribution were respectively 40 and 61 nU/ml at the age of 9 months and 38 and 59 nU/ml at the age of 15 months. The 95th and 99th percentiles of the GAA distribution were respectively 0.020 and 0.046 at the age of 9 months and 0.022 and 0.098 at the age of 15 months. We propose to use IAA levels greater than 60 nU/ml and GAA index greater than 0.05 to define the presence of beta-cell autoimmunity in children younger than 2 years.