Reasons for rejecting potential donors from a sperm bank program

Purpose: Recruiting donors to a sperm bank program is difficult and slow because of high dropout rates and high rejection rates. The profile of successful and unsuccessful donors was determined at our sperm bank. Methods: A total of 199 men was screened from 1986 to 1994 in the anonymous sperm bank donor program; 174 (87%) men dropped out or did not meet minimum guidelines. The study included 25 accepted donors and 20 rejected men (of 52 rejected donors, only 20 donors who came for two consecutive semen analyses were selected). Sperm quality variables and demographic data were compared between the groups. Results: Accepted donors had significantly better semen quality in motility, velocity, linearity, and ALH than did rejected donors (P < 0.01). More rejected donors than accepted donors were single (P < 0.01). A higher percentage of accepted donors consumed caffeine (P < 0.001), and they were more likely to have college degrees (P < 0.03). Conclusions: These results indicate that loss of interest and poor semen quality were the major reasons for rejection of donors in our anonymous donor sperm bank program.     

Network-related mechanisms may help explain long-term HIV-1 seroprevalence levels that remain high but do not approach population-group saturation

In many cities, human immunodeficiency virus (HIV)-1 seroprevalence among drug injectors stabilizes at 30-70% for many years without secondary outbreaks that increase seroprevalence by 15% or more. The authors considered how HIV-1 incidence can remain moderate at seroprevalence levels that would give maximum incidence. Previously suggested answers include behavioral risk reduction and network saturation within high-risk subgroups. Among 767 drug injectors studied in 1991-1993, during a period of stable high seroprevalence in New York City, risk behaviors remained common, and networks were far from saturated. The authors suggest a different network-based mechanism: in stable high-prevalence situations, the relatively small sizes of subnetworks of linked seronegatives (within larger networks containing both infected and uninfected persons) may limit infectious outbreaks. Any primary infection outbreak would probably be limited to members of connected subcomponents of seronegatives, and the largest such subcomponent in the study contained only 18 members (of 415 seronegatives). Research and mathematical modeling should study conditions that may affect the size and stability of subcomponents of seronegatives. Finally, if the existence of small, connected components of seronegatives prevents secondary outbreaks, this protection may weaken, and vulnerability to new outbreaks increase, if HIV-1 seroprevalence falls. Thus, in situations of declining prevalence, prevention programs should be maintained or strengthened.     

Inhibition of intracellular Ca2+ signalling, cytotoxicity and antitumor activity of the herbicide oryzalin and its analogues

Purpose: Studies were conducted on oryzalin (3,5-dinitro-N,N-di(n-propyl)sulfanilamide), a widely used dinitroaniline sulfonamide herbicide, which was identified from plant extracts as an inhibitor of mitogen- and growth factor-mediated intracellular free Ca²⁺ ([Ca²⁺]_i) signalling in mammalian cells. Methods and Results: Oryzalin inhibited vasopressin, bradykinin and platelet-derived growth factor [Ca²⁺]_i signalling in Swiss 3T3 fibroblasts with IC₅₀ values of 14, 16 and 18 μM, respectively. ⁴⁵Ca²⁺ uptake into nonmitochondrial stores of saponin-permeabilized Swiss 3T3 cells was inhibited by oryzalin with an IC₅₀ of 34 μM. Oryzalin inhibited colony formation of HT-29 colon carcinoma cells with an IC₅₀ of 8 μM and inhibited the growth of a number of other cancer cell lines and primary human tumors in vitro with IC₅₀ values in the range 3 to 22 μM. A number of oryzalin analogues were studied and an association was found between the ability to inhibit [Ca²⁺]_i signalling and inhibition of the growth of HT-29 human colon cancer cells (P=0.001) and of CCRF-CEM human leukemia cells (P=0.016). Oryzalin at doses up to 600 mg/kg administered orally or subcutaneously daily to mice for 3 to 10 days beginning a day after tumor inoculation inhibited the growth of murine B16 melanoma by 63% but showed no appreciable activity when administered subcutaneously or intraperitoneally to mice beginning a number of days after tumor inoculation against a variety of human tumor xenografts. The peak plasma concentration of oryzalin following repeated subcutaneous administration of oryzalin at 600 mg/kg per day to mice was 37 μM and of its major metabolite N-depropyl oryzalin was 53 μM. Conclusion: It is unlikely that the absence of significant antitumor activity of oryzalin is a result of the inability to achieve adequate plasma concentrations. Received: 24 December 1996 / Accepted: 20 March 1997     

Further evidence for a susceptibility locus for type 2 diabetes on chromosome 20q13.1-q13.2

We previously reported suggestive linkage between type 2 diabetes and markers in a region on chromosome 20q using data from a collection of 29 Caucasian families in which type 2 diabetes with middle-age-onset was segregated as an autosomal-dominant disorder. To map more precisely the susceptibility locus (or loci) within this broad region, we increased the family collection and genotyped all families for additional markers, both within the critical region and spaced over the rest of chromosome 20. Altogether 526 individuals (including 241 with diabetes) from the total collection of 43 families were included in the study. All individuals were genotyped for 23 highly polymorphic markers. Positive evidence for linkage was found for a 10-cM region on the long arm of chromosome 20q13.1-q13.2 between markers D20S119 and D20S428. The strongest evidence in two-point as well as multipoint linkage analysis (P = 1.8 x 10(-5)) occurred at the position corresponding to marker D20S196. The individuals with diabetes in the seven most strongly linked families had high serum insulin levels during fasting and 2-h post-glucose load periods. We did not find any evidence for linkage between type 2 diabetes and any other region on chromosome 20. In conclusion, our larger and more comprehensive study showed very strong evidence for a susceptibility gene for insulin-resistant type 2 diabetes located on the long arm of chromosome 20 around marker D20S196.     

Increased susceptibility to vancomycin-resistant Enterococcus intestinal colonization persists after completion of anti-anaerobic antibiotic treatment in mice.

BACKGROUND: Antibiotic-associated disruption of the indigenous intestinal microflora may persist beyond the treatment period. Although piperacillin/tazobactam inhibits the establishment of vancomycin-resistant Enterococcus (VRE) stool colonization in mice during treatment, we hypothesized that this agent and other anti-anaerobic antibiotics would increase susceptibility to colonization during the period of recovery of the intestinal microflora. DESIGN: Mice received 10(4) colony-forming units of vancomycin-resistant E. faecium by orogastric inoculation 2, 5, or 10 days after completing 5 days of subcutaneous antibiotic treatment, or both during and 2 days after the completion of treatment. Denaturing gradient gel electrophoresis (DGGE) was performed to assess changes in the intestinal microflora. RESULTS: Anti-anaerobic antibiotics (ie, piperacillin/ tazobactam, cefoxitin, and clindamycin) caused significant disruption of the indigenous microflora (mean DGGE similarity indices < or = 27% in comparison with saline controls) and promoted the establishment of high-density colonization when VRE was inoculated 2 or 5, but not 10, days following treatment (P < .001). Piperacillin/tazobactam exhibited a biphasic effect on the establishment of colonization (ie, inhibition when exposed to VRE during treatment and promotion when exposed to VRE after discontinuation of treatment), resulting in greater overall promotion of colonization than did agents with minimal anti-anaerobic activity (ie, levofloxacin, cefepime, and aztreonam) when VRE was inoculated both during and 2 days after treatment (P < .001). CONCLUSION: Patients receiving anti-anaerobic antibiotics, including piperacillin/tazobactam, may be susceptible to the establishment of high-density VRE colonization during the period of recovery of the anaerobic microflora.     

Prognostic implications of molecular and immunohistochemical profiles of the Rb and p53 cell cycle regulatory pathways in primary non-small cell lung carcinoma.

PURPOSE: Many studies have highlighted the aberrant expression and prognostic significance of individual proteins in either the Rb (particularly cyclin D1, p16INK4A, and pRb) or the p53 (p53 and p21Waf1) pathways in non-small cell lung cancer. We hypothesize that cumulative abnormalities within each and between these pathways would have significant prognostic potential regarding survival. EXPERIMENTAL DESIGN: Our study population consisted of 106 consecutive surgically resected cases of predominantly early-stage non-small cell lung cancer from the National Cancer Institute-Mayo Clinic series, and assessment of proteins involved both immunohistochemical (cyclin D1, p21Waf1, pRb, p16INK4A, and p53) and mutational analysis (p53) in relationship to staging and survival. RESULTS: Cyclin D1 overexpression was noted in 48% of the tumors, p16INK4A negative in 53%, pRb negative in 17%, p53 immunopositive in 50%, p53 mutation frequency in 48%, and p21(Waf1) overexpression in 47%, none with prognostic significance. Cyclin D1 overexpression in pRb-negative tumors revealed a significantly worse prognosis with a mean survival of 2.3 years (P = 0.004). A simultaneous p53 mutation dramatically reduced the mean survival time to 0.9 years (P = 0.007). Cyclin D1 overexpression with either a p53 mutation or a p53 overexpression was also associated with a significantly poorer prognosis (P = 0.0033 and 0.0063, respectively). CONCLUSIONS: Some cumulative abnormalities in the Rb and p53 pathways (e.g., cyclin D1 overexpression and p53 mutations) significantly cooperate to predict a poor prognosis; however, the complexity of the cell cycle protein interaction in any given tumor warrants caution in interpreting survival results when specific protein abnormalities are taken in isolation.     

Mutations in the tyrosine kinase domain of the epidermal growth factor receptor in non-small cell lung cancer.

We evaluated somatic genetic alterations in the kinase domain of the EGFR gene in the tumors of 219 non-small cell lung cancer patients of primarily Caucasian and African American origins. We identified 26 patients (12%) whose tumors had a mutation in the EGFR gene, and 11 (5%) patients carried novel genomic variations consistent with germ-line polymorphisms. All but one mutation were identified in Caucasian patients affected with adenocarcinoma. EGFR mutations were more frequent in women and in nonsmokers, but a significant portion of the affected patients were men (12 of 26) and current or past smokers accounted for half of the patients affected (13 of 26). Screening subjects with EGFR mutations may identify patients whose tumors could respond to targeted therapy using tyrosine kinase inhibitors.     

Bromobenzene-induced hepatotoxicity at the transcriptome level.

Rats were exposed to three levels of bromobenzene, sampled at 6, 24, and 48 h, and liver gene expression profiles were determined to identify dose and time-related changes. Expression of many genes changed transiently, and dependent on the dose. Few changes were identified after 6 h, but many genes were differentially expressed after 24 h, while after 48 h, only the high dose elicited large effects. Differentially expressed genes were involved in drug metabolism (upregulated GSTs, mEH, NQO1, Mrps, downregulated CYPs, sulfotransferases), oxidative stress (induced HO-1, peroxiredoxin, ferritin), GSH depletion (induced GCS-l, GSTA, GSTM) the acute phase response, and in processes like cholesterol, fatty acid and protein metabolism, and intracellular signaling. Trancriptional regulation via the electrophile and sterol response elements seemed to mediate part of the response to bromobenzene. Recovery of the liver was suggested in response to BB by the altered expression of genes involved in protein synthesis and cytoskeleton rearrangement. Furthermore, after 48 h, rats in the mid dose group showed no toxicity, and gene expression patterns resembled the normal situation. For certain genes (e.g., CYP4A, metallothioneins), intraday variation in expression levels was found, regardless of the treatment. Selected cDNA microarray measurements were confirmed using the specific and sensitive branched DNA signal amplification assay.