The morphological and cytogenetic aspects in a study of chorionic and placental biopsies in pregnant women who are over the age of 35

Perinatal pathology and morbidity takes the leading role in children pathology and morbidity today. These indices are of significance for the pregnant women of high risk group pregnant women in the age of 35 and above occupying peculiar place in this group. In this connection the morphological studies of chorion and placenta biopsies in this group of patients are important and urgent. The cytogenetical analysis of these tissues allows one to solve completely the problems of the presence or absence of chromosome fetal malformations in terms of 8-24 weeks, when the elimination of fetus is still possible.     

Occurrence of a sequence in marine cyanophages similar to that of T4 g20 and its application to PCR-based detection and quantification techniques

Viruses are ubiquitous components of marine ecosystems and are known to infect unicellular phycoerythrin-containing cyanobacteria belonging to the genus Synechococcus. A conserved region from the cyanophage genome was identified in three genetically distinct cyanomyoviruses, and a sequence analysis revealed that this region exhibited significant similarity to a gene encoding a capsid assembly protein (gp20) from the enteric coliphage T4. The results of a comparison of gene 20 sequences from three cyanomyoviruses and T4 allowed us to design two degenerate PCR primers, CPS1 and CPS2, which specifically amplified a 165-bp region from the majority of cyanomyoviruses tested. A competitive PCR (cPCR) analysis revealed that cyanomyovirus strains could be accurately enumerated, and it was demonstrated that quantification was log-linear over ca. 3 orders of magnitude. Different calibration curves were obtained for each of the three cyanomyovirus strains tested; consequently, cPCR performed with primers CPS1 and CPS2 could lead to substantial inaccuracies in estimates of phage abundance in natural assemblages. Further sequence analysis of cyanomyovirus gene 20 homologs would be necessary in order to design primers which do not exhibit phage-to-phage variability in priming efficiency. It was demonstrated that PCR products of the correct size could be amplified from seawater samples following 100x concentration and even directly without any prior concentration. Hence, the use of degenerate primers in PCR analyses of cyanophage populations should provide valuable data on the diversity of cyanophages in natural assemblages. Further optimization of procedures may ultimately lead to a sensitive assay which can be used to analyze natural cyanophage populations both quantitatively (by cPCR) and qualitatively following phylogenetic analysis of amplified products.     

131I treatment of 131I negative whole body scan, and positive thyroglobulin in differentiated thyroid carcinoma: what is being treated?

Several aspects of the management of differentiated thyroid cancer cause considerable controversy. Among these is the role of 131I therapy in patients after thyroidectomy. There is no controlled study to demonstrate whether this treatment reduces the recurrence rate or improves mortality. Because of the overall excellent prognosis, it is unlikely that a controlled study will ever be conducted. Most frequently, patients have a diagnostic scan with 131I to determine whether radioiodine would be an appropriate therapy and to judge much to be prescribed, based on the extent of abnormalities seen on the scintiscan. Serum thyroglobulin (Tg) has been found to be a valuable tumor marker, with very good sensitivity and specificity. In most patients, the result of whole-body 131I scintiscan and Tg measurement give concordant results. However, in some patients, Tg is measurable, but the diagnostic scan with 131 is normal. There has been data published about treatment of these patients with therapeutic doses of 131I. The author questions whether this treatment is appropriate, prompted by seeing and hearing of patients who were treated with therapeutic doses of 131I, but had no abnormal uptake of the therapeutic doses and who had no improvement in serum Tg level. These patients have no clinical evidence of disease, and the only abnormality is measurable Tg. Since large doses of radioiodine are not without problems, a controlled clinical trial should be developed to evaluate efficacy in this situation.     

Probing the nucleotide binding sites of axonemal dynein with the fluorescent nucleotide analogue 2'(3')-O-(-N-Methylanthraniloyl)-adenosine 5'-triphosphate

MantATP [2'(3')-O-(-N-methylanthraniloyl)-adenosine 5'-triphosphate] was employed as a fluorescence probe of the nucleotide-binding sites of dynein from sea urchin sperm flagella. MantATP binds specifically with enhanced fluorescence (approximately 2.2-fold), homogeneous lifetime (8.4 ns), and high anisotropy (r approximately 0.38) to dynein and can be displaced by ATP and ADP added to the medium. The association constants of mantATP complexed with dynein were determined from anisotropy titration data. Using a multiple stepwise equilibrium model, the average values of the first two association constants are K1 = 2.7 x 10(5) M-1 and K2 = 1.8 x 10(4) M-1. This value of K1 is 7-8 times higher than that found previously for unsubstituted ATP, whereas K2 is little changed [Mocz and Gibbons (1996) Biochemistry 35, 9204-9211]. The lower-affinity binding sites, K3 and K4, observed previously could not be studied with mantATP within the available protein concentrations. The alpha and beta heavy chain subfractions have binding parameters similar to those of intact dynein. Formation of the stable ternary complex of mantATP with dynein and monomeric vanadate is accompanied by only a moderate increase in the binding affinities. Oligomeric vanadate reduces the binding affinities by approximately 50%. Addition of TritonX-100, methanol, or various salts changes the binding affinities by up to 50%, suggesting that the microenvironment of the nucleotide-binding sites involves significant contributions from both polar and apolar interactions. The distinct affinities of the individual binding sites are consistent with a physiological role in regulating nucleotide binding.     

Intravenous immunoglobulin treatment in multiple sclerosis

In in vivo tumor growth experiments it is common to report the tumor measurement time at which the volume distributions of the treatment groups become significantly different. This method of analysis, as commonly practiced, is deficient in that its type I error rate exceeds the usual nominal rate of 5%, unless one specifically corrects for multiple comparisons. A second problem is that many investigators evidently interpret the time of first significance as a statistical parameter--i.e., a fixed but unknown property of the model that one can estimate by experimentation. In fact the time until first significance, like the power of the test, depends both on true model parameters (such as mean growth curves and experimental variability) and on features of the experimental design, such as the sample size and the spacing of the measurement times. We argue that investigators would do better to compare treatment groups by modeling tumor growth curves or estimating volume doubling times.     

Therapeutic approaches to primary and secondary brain tumours

INTRODUCTION: This study examined the long-term effects of hysterectomy, with and without bilateral oophorectomy, and treatment with estrogen replacement on bone mineral density in older hysterectomized women. METHODS: Subjects were 346 women 60-89 years of age, who were participants in the Rancho Bernardo Study and attended a follow-up clinic visit in 1988-1991. Bone density was measured at the ultradistal wrist, midshaft radius, lumbar spine and hip. RESULTS: Of these women, 182 had a hysterectomy with conservation of one or both ovaries and 164 had a hysterectomy with bilateral oophorectomy. Current estrogen users had the highest bone densities; those who never used estrogen replacement had the lowest. Only 9.1% of oophorectomized women, compared to 19.2% of those with ovarian conservation had never used estrogen (P < .01). After adjustment for covariates including estrogen replacement therapy, hysterectomized women with ovarian conservation had marginally higher bone densities at the wrist (P < .09) and spine (P < .06) than oophorectomized women. We found significant differences only among women currently using estrogen (P < .05 for wrist and P < .01 for spine densities, respectively). Bone density did not differ at any site by oophorectomy status among past or never users of estrogen. CONCLUSIONS: Hysterectomized women who use estrogen replacement therapy have better bone density, regardless of a bilateral oophorectomy. In addition, bilateral oophorectomy may not have a long-term negative effect on bone density; hysterectomized women who do not use estrogen appear to have equivalent bone density whether or not they had a bilateral oophorectomy.     

The prevention of rain penetration through external walls and joints by means of pressure equalization

The mechanisms of rain penetration through walls and joints are described and a theory explaining the function of the pressure equalizing rain-screen wall is reviewed. The results of laboratory tests substantially confirming this theory are presented.The paper explains why some traditionally satisfactory forms of construction perform well, and suggests that the principles of pressure equalization should be applied when forms of wall construction and joints are developed and appraised. Through better understanding of these it should be possible to design and construct walls from which the problems of rain penetration is virtually eliminated.