Detecting pre-ovulatory luteinizing hormone surges in urine

The study objectives were to determine (i) if pre-ovulatory luteinizing hormone (LH) surges, undetected in urine by two immunoradiometric assays (IRMA), were detectable by an ultrasensitive immunofluorometric assay (IFMA) and (ii) the influence of creatinine adjustment on the detection and timing of the urinary LH surges. Daily urine specimens were contributed by healthy 25-36 year old volunteers during 14 ovulatory menstrual cycles for an epidemiological study conducted in 1983-1985. Specimens were selected as having been previously assayed by two IRMA without consistently detecting LH surges. These urine specimens were remeasured using an IFMA and adjusted for creatinine concentration. IFMA measurements revealed unambiguous LH surges in all cycles. Adjusting IRMA urinary LH values for creatinine concentrations revealed previously undetected LH surges in four of eight cycles. Creatinine adjustment also altered the timing of IRMA and IFMA LH surges by 1-5 days. These results demonstrate an IFMA that detects pre- ovulatory LH surges in unpreserved, frozen urine from cycles where such surges were previously undetectable. Further, creatinine adjustment can markedly affect detection and timing of the onset and peak of the urinary LH surge. While our analysis suggests that this adjustment improves the validity of the LH measure, this requires further investigation.      

Development of allergy in children. I. Association with virus infections.

Children born into allergic families, with two allergic parents, are at high risk of developing allergy within the first 5 years of life. In order to observe possible external factors in the sensitization process, a prospective study of 13 such children was done, in which serial clinical and immunologic observations were made at 3- to 6-month intervals over a period of 1 to 4 yr. Eleven of these children are now clinically allergic; 5 have asthma. Immunologic evidence for allergic sensitization was observed in these 11 children by RAST, antigen-induced leukocyte histamine release, lymphoblastogenesis, and rise in serum IgE. Upper respiratory infections (URI) occurred in these 11 allergic children 1 to 2 months prior to the onset of allergic sensitization. In 10 of these 11 URI children, complement-fixing antibodies to viruses (parainfluenza, RSV, CMV) increased in the same blood samples in which immunologic allergic sensitization was first evidenced. This coincidence suggests that certain viruses may contribute to the allergic sensitization process.     

Bloom's syndrome. XIX. Cytogenetic and population evidence for genetic heterogeneity

Cells with abnormally high rates of sister-chromatid exchange (SCE) are uniquely characteristic of Bloom's syndrome (BS). However, in one in five persons a minor population of cells with a low-SCE phenotype circulates in the blood. The origin and significance of the low-SCE cells in BS have never been understood, although they are assumed to arise by somatic mutation. In the present investigation, the enigmatic high-SCE/low-SCE mosaicism was investigated by comparing the incidence in several subpopulations of persons in the Bloom's Syndrome Registry who exhibit the two types of cells, and a striking negative correlation emerged: in persons with BS whose parents share a common ancestor, the case in approximately half of registered persons, low-SCE cells are found only rarely; conversely, the mosaicism occurs almost exclusively in persons with BS whose parents are not known to share a common ancestor. Because those who share a common ancestor are predominantly homozygous-by-descent at the mutated BS locus, the negative correlation is interpreted to mean that the emergence of low-SCE cells in BS in some way depends on the pre-existence of compound heterozygosity. A corollary to this is that BS is genetically heterogeneous.     

Retrospective multicentre study on mechanical and enzymatic preparation of fresh and cryopreserved testicular biopsies

BACKGROUND: Isolation of sperm suitable for ICSI from fresh or frozen-thawed testicular sperm extraction (TESE) can be facilitated by mechanical or enzymatic processing of the samples. METHODS: A retrospective multicentre study was initiated to compare these two approaches. Eleven German centres provided data on their TESE cycles performed during the period 1996/1997. Quality of retrieved sperm, fertilization rates of injected oocytes, embryo quality, resulting pregnancy rates and evolution of pregnancies were evaluated. RESULTS: The percentage of cycles with at least some motile sperm available for injection was higher after mechanical preparation. Independent of the preparation method, fertilization rates were higher for motile compared with immotile sperm or elongated spermatids in all groups and in general higher for cryopreserved versus fresh samples. Embryo quality was significantly better after injection of motile sperm for all treatments and in particular after enzymatic versus mechanical processing of biopsies. Pregnancy rates were identical for embryos derived from sperm prepared mechanically or enzymatically from fresh or cryopreserved testicular samples. The abortion rate (32/172, 18.6%) and the rate of multiple implantations (32/140, 22.9%) were not different from results reported in the literature for ICSI using ejaculated sperm. CONCLUSION: In this retrospective multicentre study, no unequivocal advantage of one over the other preparation method could be identified in 839 ICSI cycles using testicular sperm from 549 patients.     

Bloom''s Syndrome. VII. Progress report for 1978

The Bloom's Syndrome Registry was published in this journal in 1977. Now, in the first in a series of progress reports, recent accessions to the Registry are recorded, new instances of neoplasia are listed, and recent clinical observations and experimental results of general interest are cited.     

Carrier Frequency of the Bloom SyndromeblmMutation in the Ashkenazi Jewish Population

Bloom syndrome is more common in individuals of Ashkenazi Jewish descent than in any other population, and one particular mutation in the Bloom syndrome gene,blm^Ash,is homozygous in nearly all Ashkenazi Jewish persons with Bloom syndrome. We have determined the frequency ofblm^Ashin 1491 Ashkenazi Jewish persons with no known history of Bloom syndrome and found that 1 in 107 persons was heterozygous. Although not common, genetic screening for Bloom syndrome is feasible in this population.     

Predictors of perceived health status in elderly men and women. The Cardiovascular Health Study

Baseline data on the perceived health status of participants (N = 5,201) in the Cardiovascular Health Study of the Elderly (CHS) are reported. The authors examined the predictive utility of health-related factors representing eight different domains, assessed gender differences in the prediction of perceived health, and tested a hypothesis regarding the role of known clinical conditions versus subclinical disease in predicting perceived health. Multivariate analyses showed that the majority of the explained variance in self-assessed health is accounted for by variables that fall into four general categories. Although gender differences were small, the analysis showed that the relative importance of several predictor variables did vary by gender.     

Catechin is present as metabolites in human plasma after consumption of red wine.

Flavonoids are components of fruits, vegetables and wines. An abundance of flavonoids in the diet is correlated with reduced heart disease mortality, suggesting that they act as protective nutrients. However, little is known about the absorption and metabolism of flavonoids after normal foods are consumed. This study measured the levels of one abundant flavonoid, (+)-catechin, and its metabolites in plasma after five male and four female volunteers consumed 120 mL of red wine (RW) one day and de-alcoholized red wine (DRW) on a separate day. Each wine sample contained 35 +/- 1 mg catechin (mean +/- SEM). Plasma levels of catechin and its metabolite 3'-O-methylcatechin (3'MC) were determined by gas chromatography-mass spectrometry (GC-MS) of the trimethylsilylated (TMS) derivatives. Glucuronide and sulfate conjugates were determined after enzymatic hydrolysis. Before RW or DRW consumption, plasma levels of catechin, 3'MC and all conjugates were <2 nmol/L. After 1 h, average levels of catechin, 3'MC and all conjugates increased to 91 +/- 14 nmol/L (RW) and 81 +/- 11 nmol/L (DRW). At 1 h, 21 +/- 1% of the metabolites were methylated and <2% of catechin and 3'MC were unconjugated. Catechin was present as both a sulfate conjugate and a conjugate containing both glucuronide and sulfate residues. 3'MC was present primarily as a glucuronide conjugate. At every time point, catechin was present almost exclusively as metabolites, and these levels were independent of ethanol. Therefore, if flavonoids are protective nutrients, the active forms are likely to be metabolites, which are far more abundant in plasma than the forms that exist in foods.