Periodontal infection as a possible risk factor for preterm low birth weight

Peridontal diseases are gram-negative anaerobic infections that can occur in women of childbearing age (18 to 34 years). In the present investigation we sought to determine whether the prevalence of maternal periodontal infection could be associated with preterm low birth weight (PLBW), controlling for known risk factors and potential covariates. A case-control study of 124 pregnant or postpartum mothers was performed. PLBW cases were defined as a mother with a birth of less than 2,500 g and one or more of the following: gestational age < 37 weeks, preterm labor (PTL), or premature rupture of membranes (PROM). Controls were normal birth weight infants (NBW). Assessments included a broad range of known obstetric risk factors, such as tobacco use, drug use, alcohol consumption, level of prenatal care, parity, genitourinary infections, and nutrition. Each subject received a periodontal examination to determine clinical attachment level. PLBW cases and primiparous PLBW cases (n = 93) had significantly worse periodontal disease than the respective NBW controls. Multivariate logistic regression models, controlling for other risk factors and covariates, demonstrated that periodontal disease is a statistically significant risk factor for PLBW with adjusted odds ratios of 7.9 and 7.5 for all PLBW cases and primiparous PLBW cases, respectively. These data indicate that periodontal diseases represent a previously unrecognized and clinically significant risk factor for preterm low birth weight as a consequence of either PTL or preterm PROM.

A small cosmid for efficient cloning of large DNA fragments

The production and use of the 6 kb cosmid pHC79, a derivative of pBR322, is described. It can be used for cloning of fragments cleaved by EcoRI, ClaI, BamHI (also BglII, BclI, Sau3A and MboI), SalI (also XhoI and AvaI), EcaI and PstI. Hybrid cosmids containing inserts in the size range of 40 kb are packaged in vitro and transduced with an efficiency of 5 X 10(4) - 5 X 10(5) clones/microgram of insert DNA. Prefractionation of the DNA fragments to be cloned into 40 kb sized fragments ensures the cloning of contiguous stretches of DNA. Proteins produced in vitro by the cosmid pHC79 are identical to the ones produced by its pBR322 parent.

Global epidemiology of amyotrophic lateral sclerosis: a systematic review of the published literature

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is relatively rare, yet the economic and social burden is substantial. Having accurate incidence and prevalence estimates would facilitate efficient allocation of healthcare resources.

OBJECTIVE

To provide a comprehensive and critical review of the epidemiological literature on ALS.

METHODS

MEDLINE and EMBASE (1995-2011) databases of population-based studies on ALS incidence and prevalence reporting quantitative data were analyzed. Data extracted included study location and time, design and data sources, case ascertainment methods and incidence and/or prevalence rates. Medians and interquartile ranges (IQRs) were calculated, and ALS case estimates were derived using 2010 population estimates.

RESULTS

In all, 37 articles met the inclusion criteria. In Europe, the median incidence rate (/100,000 population) was 2.08 (IQR 1.47-2.43), corresponding to an estimated 15,355 (10,852-17,938) cases. Median prevalence (/100,000 population) was 5.40 (IQR 4.06-7.89), or 39,863 (29,971-58,244) prevalent cases.

CONCLUSIONS

Disparity in rates among ALS incidence and prevalence studies may be due to differences in study design or true variations in population demographics such as age and geography, including environmental factors and genetic predisposition. Additional large-scale studies that use standardized case ascertainment methods are needed to more accurately assess the true global burden of ALS.

Accelerated titration designs for phase I clinical trials in oncology

BACKGROUND

Many cancer patients in phase I clinical trials are treated at doses of chemotherapeutic agents that are below the biologically active level, thus reducing their chances for therapeutic benefit. Current phase I trials often take a long time to complete and provide little information about interpatient variability or cumulative toxicity.

PURPOSE

Our objective was to develop alternative designs for phase I trials so that fewer patients are treated at subtherapeutic dose levels, trials are of reduced duration, and important information (i.e., cumulative toxicity and maximum tolerated dose) needed to plan phase II trials is obtained.

METHODS

We fit a stochastic model to data from 20 phase I trials involving the study of nine different drugs. We then simulated new data from the model with the parameters estimated from the actual trials and evaluated the performance of alternative phase I designs on this simulated data. Four designs were evaluated. Design 1 was a conventional design (similar to the commonly used modified Fibonacci method) using cohorts of three to six patients, with 40% dose-step increments and no intrapatient dose escalation. Designs 2 through 4 included only one patient per cohort until one patient experienced dose-limiting toxic effects or two patients experienced grade 2 toxic effects (during their first course of treatment for designs 2 and 3 or during any course of treatment for design 4). Designs 3 and 4 used 100% dose steps during this initial accelerated phase. After the initial accelerated phase, designs 2 through 4 resorted to standard cohorts of three to six patients, with 40% dose-step increments. Designs 2 through 4 used intrapatient dose escalation if the worst toxicity is grade 0-1 in the previous course for that patient.

RESULTS

Only three of the actual trials demonstrated cumulative toxic effects of the chemotherapeutic agents in patients. The average number of patients required for a phase I trial was reduced from 39.9 for design 1 to 24.4, 20.7, and 21.2 for designs 2, 3, and 4, respectively. The average number of patients who would be expected to have grade 0-1 toxicity as their worst toxicity over three cycles of treatment is 23.3 for design 1, but only 7.9, 3.9, and 4.8 for designs 2, 3, and 4, respectively. The average number of patients with grade 3 toxicity as their worst toxicity increases from 5.5 for design 1 to 6.2, 6.8, and 6.2 for designs 2, 3, and 4, respectively. The average number of patients with grade 4 toxicity as their worst toxicity increases from 1.9 for design 1 to 3.0, 4.3, and 3.2 for designs 2, 3, and 4, respectively.

CONCLUSION

Accelerated titration (i.e., rapid intrapatient drug dose escalation) designs appear to effectively reduce the number of patients who are under-treated, speed the completion of phase I trials, and provide a substantial increase in the information obtained.

Fertility and ageing

The late 20th century trend to delay birth of the first child until the age at which female fecundity or reproductive capacity is lower has increased the incidence of age-related infertility. The trend and its consequences have also stimulated interest in the possible factors in the female and the male that may contribute to the decline in fecundity with age; in the means that exist to predict fecundity; and in the consequences for pregnancy and childbirth. In the female, the number of oocytes decreases with age until the menopause. Oocyte quality also diminishes, due in part to increased aneuploidy because of factors such as changes in spindle integrity. Although older male age affects the likelihood of conception, abnormalities in sperm chromosomes and in some components of the semen analysis are less important than the frequency of intercourse. Age is as accurate as any other predictor of conception with assisted reproductive technology. The decline in fecundity becomes clinically relevant when women reach their mid-30s, when even assisted reproduction treatment cannot compensate for the decline in fecundity associated with delaying attempts at conceiving. Pregnancies among women aged >40 years are associated with more non-severe complications, more premature births, more congenital malformations and more interventions at birth.

Identifying breast cancer patients at risk for Central Nervous System (CNS) metastases in trials of the International Breast Cancer Study Group (IBCSG)

BACKGROUND

We sought to determine whether a high-risk group could be defined among patients with operable breast cancer in whom a search of occult central nervous system (CNS) metastases was justified.

PATIENTS AND METHODS

We evaluated data from 9524 women with early breast cancer (42% node-negative) who were randomized in International Breast Cancer Study Group clinical trials between 1978 and 1999, and treated without anthracyclines, taxanes, or trastuzumab. We identified patients whose site of first event was CNS and those who had a CNS event at any time.

RESULTS

Median follow-up was 13 years. The 10-year incidence (10-yr) of CNS relapse was 5.2% (1.3% as first recurrence). Factors predictive of CNS as first recurrence included: node-positive disease (10-yr = 2.2% for > 3 N+), estrogen receptor-negative (2.3%), tumor size > 2 cm (1.7%), tumor grade 3 (2.0%), < 35 years old (2.2%), HER2-positive (2.7%), and estrogen receptor-negative and node-positive (2.6%). The risk of subsequent CNS recurrence was elevated in patients experiencing lung metastases (10-yr = 16.4%).

CONCLUSION

Based on this large cohort we were able to define risk factors for CNS metastases, but could not define a group at sufficient risk to justify routine screening for occult CNS metastases.

Differing birth weight among infants of U.S.-born blacks, African-born blacks, and U.S.-born whites

BACKGROUND

In the United States, the birth weights of infants of black women are lower than those of infants of white women. The extent to which the lower birth weights among blacks are related to social or genetic factors is unclear.

METHODS

We used vital records for 1980 through 1995 from Illinois to determine the distribution of birth weights among infants born to three groups of women -- U.S.-born blacks, African-born blacks, and U.S.-born whites.

RESULTS

The mean birth weight of 44,046 infants of U.S.-born white women was 3446 g, that of 3135 infants of African-born black women was 3333 g, and that of 43,322 infants of U.S.-born black women was 3089 g. The incidence of low birth weight (weight less than 2500 g) was 13.2 percent among infants of U.S.-born black women and 7.1 percent among infants of African-born black women, as compared with 4.3 percent among infants of U.S.-born white women (relative risks, 3.1 and 1.6, respectively). Among the women at lowest risk (those 20 to 39 years old, with 12 years of education for themselves and their spouses, early prenatal care, gravida 2 or 3, and no previous fetal loss), the rate of low birth weight in infants of African-born black women (3.6 percent) was closer to the rate in infants of U.S.-born white women (2.4 percent), and the rate in infants of U.S.-born black women remained high (7.5 percent).

CONCLUSIONS

The birth-weight patterns of infants of African-born black women and U.S.-born white women are more closely related to one another than to the birth weights of infants of U.S.-born black women.

Acceleration of lung disease in children with cystic fibrosis after Pseudomonas aeruginosa acquisition

As part of the ongoing Wisconsin Cystic Fibrosis (CF) Neonatal Screening Project, we had the unique opportunity to study the longitudinal relationship between Pseudomonas aeruginosa (Pa) acquisition and infection and developing lung disease in children with CF. The primary objective was to determine whether acquisition of Pa was associated with a measurable change in the progression of lung disease. Two outcome measures were used to study 56 patients who were diagnosed through newborn screening: 1) Wisconsin additive chest radiograph score (WCXR), based on the average of scores from a pulmonologist and a radiologist, and 2) the highest forced expired volume in 1 sec (FEV(1))/forced vital capacity (FVC) ratio. We used two measures of Pa acquisition: 1) time of first positive protocol-determined oropharyngeal (with cough) culture, and 2) the magnitude of antibody titer detected by ELISA assays, using as antigen a crude cell lysate, purified exotoxin A, or an elastase toxoid prepared from three Pa strains. Other predictor variables included age, pancreatic status, height-for age, and weight-for-age-percentiles. The best regression model for predicting changes in the WCXR included time to first positive culture and antibody titer for Pa elastase. Prior to Pa acquisition, WCXR worsened by 0.45 points/year (P > 0.25); after Pa acquisition, the rate of worsening increased significantly (P < 0.001) to 1.40 points/year. Each antibody titer level (log base 2) increased the score by 0.48 points (P < 0.001). The best regression model for predicting change in the FEV(1)/FVC included only time to first positive culture. Prior to Pa acquisition, the FEV(1)/FVC ratio declined by 1.29%/year; after Pa infection, the rate of decrease significantly accelerated to 1.81%/year (P = 0.001). Our data show that Pa acquisition is associated with declining pulmonary status in children with CF, and that this effect is probably gradual rather than precipitous. Because these patients were diagnosed and treated aggressively, our estimates of the effects of Pa acquisition may be conservative. We also conclude that the WCXR appears to be more sensitive than FEV(1)/FVC in detecting early changes in lung disease associated with CF.

CP-154,526: a potent and selective nonpeptide antagonist of corticotropin releasing factor receptors

Here we describe the properties of CP-154,526, a potent and selective nonpeptide antagonist of corticotropin (ACTH) releasing factor (CRF) receptors. CP-154,526 binds with high affinity to CRF receptors (Ki < 10 nM) and blocks CRF-stimulated adenylate cyclase activity in membranes prepared from rat cortex and pituitary. Systemically administered CP-154,526 antagonizes the stimulatory effects of exogenous CRF on plasma ACTH, locus coeruleus neuronal firing and startle response amplitude. Potential anxiolytic activity of CP-154,526 was revealed in a fearpotentiated startle paradigm. These data are presented in the context of clinical findings, which suggest that CRF is hypersecreted in certain pathological states. We propose that a CRF antagonist such as CP-154,526 could affirm the role of CRF in certain psychiatric diseases and may be of significant value in the treatment of these disorders.

Hydroperoxide assay with the ferric-xylenol orange complex

A range of hydroperoxides were reduced by ferrous ions in acid solutions and the amount of ferric product was measured as a xylenol orange complex at 560 nm. Dilute sulfuric acid, 50% acetic acid, and acidified 90% methanol proved to be suitable solvents. The color developed within 15 min and was stable for several hours in most solvents. The apparent molar absorption coefficients (epsilon(app)) of H(2)O(2) and of the t-butyl, cumene, bovine serum albumin, and linoleate hydroperoxides were measured, using known hydroperoxide concentrations determined independently by an iodometric assay. The epsilon(app) values differed significantly and depended on the hydroperoxide, the solvent, and the source of the xylenol orange. The numbers of Fe(3+) ions formed by a range of hydroperoxides in different solvents showed that H(2)O(2) gave 2.5, t-butyl and cumene hydroperoxides 5, and the other hydroperoxides 2 Fe(3+) ions per -OOH group. This general finding allows the determination of approximate hydroperoxide concentrations even in chemically complex systems. Accurate measurements require knowledge of the nature of the hydroperoxide and its epsilon(app) and careful control of the assay conditions. However, the convenience of the assay makes it potentially useful in a variety of applications.

Burdens and benefits of adjuvant cyclophosphamide, methotrexate, and fluorouracil and tamoxifen for elderly patients with breast cancer: the International Breast Cancer Study Group Trial VII

PURPOSE

Information on the tolerability and efficacy of adjuvant chemoendocrine therapy for older women is limited. We studied these issues using the data collected as part of the International Breast Cancer Study Group Trial VII.

PATIENTS AND METHODS

Postmenopausal women with operable, node-positive breast cancer were randomized to receive either tamoxifen alone for 5 years (306 patients) or tamoxifen plus three consecutive cycles of classical cyclophosphamide (100 mg/m(2) orally days 1 to 14), methotrexate (40 mg/m(2) intravenous days 1 and 8), and fluorouracil (600 mg/m(2) intravenous days 1 and 8) every 28 days (CMF; 302 patients). The median follow-up was 8.0 years.

RESULTS

Among the 299 patients who received at least one dose of CMF, women 65 years of age or older (n = 76) had higher grades of toxicity compared with women less than 65 years old (n = 223) (P =.004). More women in the older age group compared with the younger women experienced grade 3 toxicity of any type (17% v 7%, respectively), grade 3 hematologic toxicity (9% v 5%, respectively), and grade 3 mucosal toxicity (4% v 1%, respectively). Older patients also received less than their expected CMF dose compared with younger postmenopausal women (P =.0008). The subjective burdens of treatment, however, were similar for younger and older patients based on quality-of-life measures (performance status, coping, physical well-being, mood, and appetite). For older patients, the 5-year disease-free survival (DFS) rates were 63% for CMF plus tamoxifen and 61% for tamoxifen alone (hazards ratio [HR], 1.00; 95% confidence interval [CI], 0.65 to 1.52; P =.99). For younger patients, the corresponding 5-year DFS rates were 61% and 53% (HR, 0.70; 95% CI, 0.53 to 0.91; P =.008), but the test for heterogeneity of CMF effect according to age group was not statistically significant. The reduced effectiveness of CMF among older women could not be attributed to dose reductions according to dose received.

CONCLUSION

CMF tolerability and effectiveness were both reduced for older patients compared with younger postmenopausal node-positive breast cancer patients who received tamoxifen for 5 years. The development and evaluation of less toxic and more effective chemotherapy regimens are required for high-risk elderly patients.

Intestinal microbiota influence the early postnatal development of the enteric nervous system

BACKGROUND

Normal gastrointestinal function depends on an intact and coordinated enteric nervous system (ENS). While the ENS is formed during fetal life, plasticity persists in the postnatal period during which the gastrointestinal tract is colonized by bacteria. We tested the hypothesis that colonization of the bowel by intestinal microbiota influences the postnatal development of the ENS.

METHODS

The development of the ENS was studied in whole mount preparations of duodenum, jejunum, and ileum of specific pathogen-free (SPF), germ-free (GF), and altered Schaedler flora (ASF) NIH Swiss mice at postnatal day 3 (P3). The frequency and amplitude of circular muscle contractions were measured in intestinal segments using spatiotemporal mapping of video recorded spontaneous contractile activity with and without exposure to lidocaine and N-nitro-L-arginine (NOLA).

KEY RESULTS

Immunolabeling with antibodies to PGP9.5 revealed significant abnormalities in the myenteric plexi of GF jejunum and ileum, but not duodenum, characterized by a decrease in nerve density, a decrease in the number of neurons per ganglion, and an increase in the proportion of myenteric nitrergic neurons. Frequency of amplitude of muscle contractions were significantly decreased in the jejunum and ileum of GF mice and were unaffected by exposure to lidocaine, while NOLA enhanced contractile frequency in the GF jejunum and ileum.

CONCLUSIONS & INFERENCES

These findings suggest that early exposure to intestinal bacteria is essential for the postnatal development of the ENS in the mid to distal small intestine. Future studies are needed to investigate the mechanisms by which enteric microbiota interact with the developing ENS.

Is chemotherapy alone adequate for young women with oestrogen-receptor-positive breast cancer?

BACKGROUND

The prognosis of breast cancer in very young women is generally considered to be unfavourable. Therefore, the outcome of adjuvant therapy was analysed in a population of young (<35 years) premenopausal patients treated in four randomised controlled trials.

METHODS

Between 1978 and 1993 the International Breast Cancer Study Group (IBCSG) treated 3700 premenopausal and perimenopausal patients with various timing and duration of adjuvant cyclophosphamide, methotrexate, and fluorouracil (CMF with or without low-dose prednisone and oophorectomy). 314 of these women were less than 35 years old at randomisation.

FINDINGS

Relapse and death occurred earlier and more often in younger (<35 years) than in older (> or = 35) patients with a 10 year disease-free survival of 35% (SE 3) versus 47% (1) (hazard ratio 1.41 [95% CI 1.22-1.62], p<0.001) and overall survival of 49% (3) versus 62% (1) (1.50 [1.28-1.77], p<0.001). Younger patients with oestrogen-receptor positive tumours had a significantly worse disease-free survival than younger patients with oestrogen-receptor negative tumours. By contrast, among older patients the disease-free survival was similar irrespective of oestrogen-receptor status.

INTERPRETATION

Young premenopausal breast cancer patients treated with adjuvant CMF chemotherapy had higher risk of relapse and death than older premenopausal patients, especially if their tumours expressed oestrogen receptors. The endocrine effects of chemotherapy alone are insufficient for the younger age group and these patients should strongly consider additional endocrine therapies (tamoxifen or ovarian ablation) if their tumours express oestrogen receptors.

Altered colonic function and microbiota profile in a mouse model of chronic depression

BACKGROUND

Depression often coexists with the irritable bowel syndrome (IBS) which is characterized by alterations in gut function. There is emerging evidence that the microbial composition (microbiota) of the gut is altered in IBS, but the basis for this is poorly understood. The aim of this study was to determine whether the induction of chronic depression results in changes in the colonic function and in its microbial community, and to explore underlying mechanisms.

METHODS

Bilateral olfactory bulbectomy (OBx) was used to induce depression-like behavior in mice. Colonic function was assessed by measuring muscle contractility, pellet excretion, c-fos activity, and serotonin levels. Microbiota profiles were obtained using denaturing gradient gel electrophoresis (DGGE). The hypothalamic-pituitary axis (HPA) was assessed by the hypothalamic expression of corticotropin-releasing hormone (CRH). In separate studies, mice without OBx received CRH via intracerebroventricular (ICV) infusion for 4 weeks prior to assessing colonic function and microbiota profiles.

KEY RESULTS

Olfactory bulbectomy mice demonstrated chronic depression- and anxiety-like behaviors associated with elevated central CRH expression and increases in c-Fos activity, serotonin levels, and motility in the colon. These changes were accompanied by an altered intestinal microbial profile. Central CRH administration produced similar changes in behavior and motility and altered the microbiota profile in the colon.

CONCLUSIONS & INFERENCES

The induction of chronic depression alters motor activity and the microbial profile in the colon likely via activation of the HPA. These findings provide a basis for linking the behavioral and gastrointestinal manifestations of IBS.

Crystal structures of native and inhibited forms of human cathepsin D: implications for lysosomal targeting and drug design

Cathepsin D (EC 3.4.23.5) is a lysosomal protease suspected to play important roles in protein catabolism, antigen processing, degenerative diseases, and breast cancer progression. Determination of the crystal structures of cathepsin D and a complex with pepstatin at 2.5 A resolution provides insights into inhibitor binding and lysosomal targeting for this two-chain, N-glycosylated aspartic protease. Comparison with the structures of a complex of pepstatin bound to rhizopuspepsin and with a human renin-inhibitor complex revealed differences in subsite structures and inhibitor-enzyme interactions that are consistent with affinity differences and structure-activity relationships and suggest strategies for fine-tuning the specificity of cathepsin D inhibitors. Mutagenesis studies have identified a phosphotransferase recognition region that is required for oligosaccharide phosphorylation but is 32 A distant from the N-domain glycosylation site at Asn-70. Electron density for the crystal structure of cathepsin D indicated the presence of an N-linked oligosaccharide that extends from Asn-70 toward Lys-203, which is a key component of the phosphotransferase recognition region, and thus provides a structural explanation for how the phosphotransferase can recognize apparently distant sites on the protein surface.

Risk factors for locoregional recurrence among breast cancer patients: results from International Breast Cancer Study Group Trials I through VII

PURPOSE

To explore prognostic factors for locoregional failures (LRF) among women treated for invasive breast cancer within clinical trials of adjuvant therapies.

PATIENTS AND METHODS

The study population consisted of 5,352 women who were treated with a modified radical mastectomy and enrolled in one of seven International Breast Cancer Study Group randomized trials. A total of 1,275 women with node-negative disease received either no adjuvant therapy or a single cycle of perioperative chemotherapy, and 4,077 women with node-positive disease received adjuvant chemotherapy of at least 3 months' duration and/or tamoxifen. Median follow-up is 12 to 15.5 years.

RESULTS

In women with node-negative disease, factors associated with increased risk of LRF were vascular invasion (VI) and tumor size greater than 2 cm for premenopausal and VI for postmenopausal patients. Of the 1,275 patients, 345 (27%) met criteria for the highest risk groups, and the 10-year cumulative incidences of LRF with or without distant metastases were 16% for premenopausal and 19% for postmenopausal women. For the node-positive cohort, number of nodes and tumor grade were factors for both menopausal groups, with additional prediction provided by VI for premenopausal and tumor size for postmenopausal patients. Of the 4,077 patients, 815 (20%) met criteria for the highest risk groups, and 10-year cumulative incidences were 35% for premenopausal and 34% for postmenopausal women.

CONCLUSION

LRFs are a significant problem after mastectomy alone even for some patients with node-negative breast cancer, as well as after mastectomy and adjuvant treatment for some subgroups of patients with node-positive disease. In addition to number of positive lymph nodes, predictors of LRF include tumor-related factors, such as vascular invasion, higher grade, and larger size.

Structure and inhibition of plasmepsin II, a hemoglobin-degrading enzyme from Plasmodium falciparum

Plasmodium falciparum is the major causative agent of malaria, a disease of worldwide importance. Resistance to current drugs such as chloroquine and mefloquine is spreading at an alarming rate, and our antimalarial armamentarium is almost depleted. The malarial parasite encodes two homologous aspartic proteases, plasmepsins I and II, which are essential components of its hemoglobin-degradation pathway and are novel targets for antimalarial drug development. We have determined the crystal structure of recombinant plasmepsin II complexed with pepstatin A. This represents the first reported crystal structure of a protein from P. falciparum. The crystals contain molecules in two different conformations, revealing a remarkable degree of interdomain flexibility of the enzyme. The structure was used to design a series of selective low molecular weight compounds that inhibit both plasmepsin II and the growth of P. falciparum in culture.

Body mass index as a prognostic feature in operable breast cancer: the International Breast Cancer Study Group experience

BACKGROUND

Current information on the prognostic importance of body mass index (BMI) for patients with early breast cancer is based on a variety of equivocal reports. Few have data on BMI in relationship to systemic treatment.

PATIENTS AND METHODS

Patients (6792) were randomized to International Breast Cancer Study Group trials from 1978 to 1993, studying chemotherapy and endocrine therapy. BMI was evaluated with eight other factors: menopausal status, nodal status, estrogen receptor status, progesterone receptor status, tumor size, vessel invasion, tumor grade and treatment. BMI was categorized as normal (< or =24.9), intermediate (25.0-29.9) or obese (> or =30.0).

RESULTS

Patients with normal BMI had significantly longer overall survival (OS) and disease-free survival (DFS) than patients with intermediate or obese BMI in pairwise comparisons adjusted for other factors. Subset analyses showed the same effect in pre- and perimenopausal patients and in those receiving chemotherapy alone. When assessed globally and adjusted for other factors, BMI significantly influenced OS (P = 0.03) but not DFS (P = 0.12).

CONCLUSIONS

BMI is an independent prognostic factor for OS in patients with breast cancer, especially among pre-/perimenopausal patients treated with chemotherapy without endocrine therapy.

Cosmids: a type of plasmid gene-cloning vector that is packageable in vitro in bacteriophage lambda heads

Evidence is presented that ColE1 hybrid plasmids carrying the cohesive-end site (cos) of lambda can be used as gene cloning vectors in conjunction with the lambda in vitro packaging system of Hohn and Murray [(1977) Proc. Natl. Acad. Sci. USA 74, 3259--3263]. Due to the requirement for a large DNA molecule for efficient packaging, there is a direct selection for hybrids carrying large sections of foreign DNA. The small vector plasmids do not contribute a large background in the transduced population, which is therefore markedly enriched for large hybrid plasmids (over 90%). The efficiency of the in vitro packaging system is on the order of 10(5) hybrid clones per microgram of foreign DNA for hybrids in the 20--30 million dalton range.

Response to mesna, doxorubicin, ifosfamide, and dacarbazine in 108 patients with metastatic or unresectable sarcoma and no prior chemotherapy

In this phase II trial, 105 eligible patients with no prior chemotherapy and advanced sarcoma received doxorubicin, ifosfamide, and dacarbazine (DTIC) with mesna uroprotection (MAID). Starting doses of these drugs were 60, 7,500, and 900 mg/m2 divided over 72 hours by continuous infusion, respectively. Mesna was given for 84 to 96 hours at 2,500 mg/m2/d. Myelosuppression was dose limiting, causing the only toxic death (sepsis). Nonhematologic toxicity consisted predominantly of anorexia and vomiting. Severe mucositis, macroscopic hematuria, renal tubular acidosis, renal failure, and CNS toxicity occurred in less than 5% of cycles. No cardiotoxicity was detected. The overall response rate (10% complete response [CR]) was 47% (95% confidence intervals, 5% to 18% and 37% to 57%, respectively). Most responses (approximately 70%) were observed within two cycles. Median times to progression were 10 and 9 months, respectively. Histologic high tumor grade, lesions less than 5 cm, and less than 1 year from diagnosis to study entry correlated with the probability of response. The median survival was 16 months. Time from diagnosis to study entry, performance status, and extent of disease, but not histologic grade, correlated with survival. Following CR, two patients remain disease-free at 32 and 16 months. Of the 15 additional patients rendered disease-free with surgery, two remain disease-free at 30 and 18 months with no further therapy. While most relapses occurred in sites of prior involvement, death from CNS metastases occurred in 11 of the 80 patients with high-grade sarcomas, of whom seven were still responding systematically (three complete responders). Because of its substantial response in this phase II trial, the MAID regimen is being compared with doxorubicin and DTIC alone in advanced sarcomas and to observation in the adjuvant treatment of high-grade sarcomas in randomized trials.

Prognostic impact of amenorrhoea after adjuvant chemotherapy in premenopausal breast cancer patients with axillary node involvement: results of the International Breast Cancer Study Group (IBCSG) Trial VI

Adjuvant chemotherapy-induced amenorrhoea has been shown to be associated with reduced relapses and improved survival for premenopausal breast cancer patients. Amenorrhoea was, therefore, studied to define features of chemotherapy (i.e. duration and timing) and disease-related factors which are associated with its treatment effects. We reviewed data from IBCSG Trial VI, in which accrual was between July 1986 and April 1993. 1196 of the 1475 eligible patients (81%) were evaluable for this analysis. The median follow-up was 60 months. Women who experienced amenorrhoea had a significantly better disease-free survival (DFS) than those who did not (P = 0.0004), although the magnitude of the effect was reduced when adjusted for other prognostic factors (P = 0.09). The largest treatment effect associated with amenorrhoea was seen in patients assigned to receive only three initial CMF courses (5-yr DFS: 67% versus 49%, no amenorrhoea; hazard ratio, 0.55; 95% confidence interval, 0.38 to 0.81; P = 0.002). DFS differences between amenorrhoea categories were larger for patients with ER/PR positive tumours (hazard ratio, 0.65; 95% confidence interval, 0.53 to 0.80; P = 0.0001). Furthermore, patients whose menses returned after brief amenorrhoea had a DFS similar to those whose menses ceased and did not recover (hazard ratio, 1.10; 95% confidence interval, 0.75 to 1.62; P = 0.63). The effects associated with a permanent or temporary chemotherapy-induced amenorrhoea are especially significant for node-positive breast cancer patients who receive a suboptimal duration of CMF chemotherapy. Cessation of menses, even for a limited time period after diagnosis of breast cancer, might be beneficial and should be prospectively investigated, especially in patients with oestrogen receptor-positive primaries.

An evaluation of a "best practices" musculoskeletal injury prevention program in nursing homes

OBJECTIVE

To conduct an intervention trial of a "best practices" musculoskeletal injury prevention program designed to safely lift physically dependent nursing home residents.

DESIGN

A pre-post intervention trial and cost benefit analysis at six nursing homes from January 1995 through December 2000. The intervention was established in January 1998 and injury rates, injury related costs and benefits, and severity are compared for 36 months pre-intervention and 36 months post-intervention.

PARTICIPANTS

A dynamic cohort of all nursing staff (n = 1728) in six nursing homes during a six year study period.

INTERVENTION

"Best practices" musculoskeletal injury prevention program consisting of mechanical lifts and repositioning aids, a zero lift policy, and employee training on lift usage.

MAIN OUTCOME MEASURES

Injury incidence rates, workers' compensation costs, lost work day injury rates, restricted work day rates, and resident assaults on caregivers, annually from January 1995 through December 2000.

RESULTS

There was a significant reduction in resident handling injury incidence, workers' compensation costs, and lost workday injuries after the intervention. Adjusted rate ratios were 0.39 (95% confidence interval (CI) 0.29 to 0.55) for workers' compensation claims, 0.54 (95% CI 0.40 to 0.73) for Occupational Safety and Health Administration (OSHA) 200 logs, and 0.65 (95% CI 0.50 to 0.86) for first reports of employee injury. The initial investment of $158 556 for lifting equipment and worker training was recovered in less than three years based on post-intervention savings of $55 000 annually in workers' compensation costs. The rate of post-intervention assaults on caregivers during resident transfers was down 72%, 50%, and 30% based on workers' compensation, OSHA, and first reports of injury data, respectively.

CONCLUSIONS

The "best practices" prevention program significantly reduced injuries for full time and part time nurses in all age groups, all lengths of experience in all study sites.

Among patients treated for IVF with gonadotrophins and GnRH analogues, is the probability of live birth dependent on the type of analogue used? A systematic review and meta-analysis

This systematic review and meta-analysis aimed to answer the following clinical question: among patients treated for IVF with gonadotrophins and GnRH analogues, is the probability of live birth per randomized patient dependent on the type of analogue used? Eligible studies were randomized controlled trials (RCTs), published as a full manuscript in a peer-reviewed journal, that contained sufficient information to allow ascertainment of whether randomization was true and whether equality was present between the groups compared. A literature search identified 22 RCTs comparing GnRH antagonists and GnRH agonists that involved 3176 subjects. Where live birth was not reported in a study that fulfilled the inclusion criteria, an effort was made to contact the corresponding authors to retrieve the missing information. If this was not possible, the reported outcome measure, clinical pregnancy or ongoing pregnancy was converted to live birth in 12 studies using published data (Arce et al., 2005). No significant difference was present in the probability of live birth between the two GnRH analogues [odds ratio (OR), 0.86; 95% confidence intervals (CI), 0.72 to 1.02]. This result remains stable in subgroup analysis that ordered the studies by type of population studied, gonadotrophin type used for stimulation, type of agonist protocol used, type of agonist used, type of antagonist protocol used, type of antagonist used, presence of allocation concealment, presence of co-intervention and the way the information on live birth was retrieved. In conclusion, the probability of live birth after ovarian stimulation for IVF does not depend on the type of analogue used for pituitary suppression.

Particle nucleation in the tropical boundary layer and its coupling to marine sulfur sources

New particle formation in a tropical marine boundary layer setting was characterized during NASA's Pacific Exploratory Mission-Tropics A program. It represents the clearest demonstration to date of aerosol nucleation and growth being linked to the natural marine sulfur cycle. This conclusion was based on real-time observations of dimethylsulfide, sulfur dioxide, sulfuric acid (gas), hydroxide, ozone, temperature, relative humidity, aerosol size and number distribution, and total aerosol surface area. Classic binary nucleation theory predicts no nucleation under the observed marine boundary layer conditions.