A perspective on color vision in platyrrhine monkeys

Studies carried out over the past two decades show that many platyrrhine (New World) monkeys have polymorphic color vision. This condition results from the sorting of allelic versions of X-chromosome cone opsin genes at a single gene site, yielding a mixture of dichromatic and trichromatic phenotypes in the population. Two genera of platyrrhine monkey are known to deviate significantly from this pattern. Examination of color vision, photopigments, and photopigment genes of all of these monkeys have stimulated a renewed interest in understanding the evolution of primate color vision.     

Partial purification of protein farnesyl cysteine carboxyl methyltransferase from bovine brain

Asian upper and lower eyelids are typically characterized by a fuller appearance than the lids of whites. Inferior extension of preaponeurotic fat and brow fat into the Asian upper lid explain the upper lid fullness and its difference from the upper lid of whites. Analogous structures in the Asian lower lid may exist to explain its full appearance. High-resolution magnetic resonance imaging (MRI) of 24 normal Asian and white lower lids was performed to evaluate differences in Asian and white lower lid anatomy. Magnetic resonance images revealed two major differences. First, the orbital fat projected further anteriorly with respect to the orbital rim in all Asian lower lids studied. No analogy with the upper lid exists for this difference. Second, the orbital fat extended further superiorly, to the inferior border of tarsus, in those Asian lower lids that did not have well defined creases. This was analogous to the preaponeurotic fat location of the Asian upper lid and different from the white lower lid. The suborbicularis oculi fat in the lower lid, the analogous structure of the brow fat pad in the upper lid, was not different in location in Asian and white lower lids. Therefore, the Asian lower lid appearance is explained by the difference in orbital fat location, which is only partly analogous to the anatomical differences between the Asian and white upper lids.     

Magnesium silicide intermetallic alloys

Methods of induction melting an ultra-low-density magnesium silicide (Mg₂Si) intermetallic and its alloys and the resulting microstructure and microhardness were studied. The highest quality ingots of Mg₂Si alloys were obtained by triple melting in a graphite crucible coated with boron nitride to eliminate reactivity, under overpressure of high-purity argon (1.3 X 10⁵ Pa), at a temperature close to but not exceeding 1105 °C ± 5 °C to avoid excessive evaporation of Mg. After establishing the proper induction-melting conditions, the Mg-Si binary alloys and several Mg₂Si alloys macroalloyed with 1 at. pct of Al, Ni, Co, Cu, Ag, Zn, Mn, Cr, and Fe were induction melted and, after solidification, investigated by optical microscopy and quantitative X-ray energy dispersive spectroscopy (EDS). Both the Mg-rich and Si-rich eutectic in the binary alloys exhibited a small but systematic increase in the Si content as the overall composition of the binary alloy moved closer toward the Mg₂Si line compound. The Vickers microhardness (VHN) of the as-solidified Mg-rich and Si-rich eutectics in the Mg-Si binary alloys decreased with increasing Mg (decreasing Si) content in the eutectic. This behavior persisted even after annealing for 75 hours at 0.89 pct of the respective eutectic temperature. The Mg-rich eutectic in the Mg₂Si + Al, Ni, Co, Cu, Ag, and Zn alloys contained sections exhibiting a different optical contrast and chemical composition than the rest of the eutectic. Some particles dispersed in the Mg₂Si matrix were found in the Mg₂Si + Cr, Mn, and Fe alloys. The EDS results are presented and discussed and compared with the VHN data. Formerly Formerly     

Improved cervical smear assessment using antibodies against proteins that regulate DNA replication

Carcinoma of the cervix is one of the most common malignancies. Papanicolaou (Pap) smear tests have reduced mortality by up to 70%. Nevertheless their interpretation is notoriously difficult with high false-negative rates and frequently fatal consequences. We have addressed this problem by using affinity-purified antibodies against human proteins that regulate DNA replication, namely Cdc6 and Mcm5. These antibodies were applied to sections and smears of normal and diseased uterine cervix by using immunoperoxidase or immunofluorescence to detect abnormal precursor malignant cells. Antibodies against Cdc6 and Mcm5 stain abnormal cells in cervical smears and sections with remarkably high specificity and sensitivity. Proliferation markers Ki-67 and proliferating cell nuclear antigen are much less effective. The majority of abnormal precursor malignant cells are stained in both low-grade and high-grade squamous intraepithelial lesions. Immunostaining of cervical smears can be combined with the conventional Pap stain so that all the morphological information from the conventional method is conserved. Thus antibodies against proteins that regulate DNA replication can reduce the high false-negative rate of the Pap smear test and may facilitate mass automated screening.     

Variable phenotype of familial adenomatous polyposis in pedigrees with 3'' mutation in the APC gene

Traumatic rupture of the corpus cavernosum is relatively frequent in the authors' experience. Based on the study of a series of 80 cases and a review of the literature, the authors analyse the diagnostic and therapeutic aspects and outcome of this disease. The patients in this series had a mean age of 30 years. Meticulous and intimate clinical interview demonstrated that the commonest mechanism is forced manipulation of the erect penis (68%). Clinical examination localized the site of the fracture (proximal: 57%, distal 43%). The fracture was unilateral (78 cases), rarely bilateral (2 cases) and associated with complete rupture of the urethra (1 case). Treatment was surgical in 79 patients. A distal semicircumferential incision was used in the case of bilateral rupture, distal rupture and associated urethral lesion (34 cases). A favourable course was observed in 86% of cases. However, 9 postoperative complications (12.5%) were observed (6 cases of fibrous plaques, 3 cases of chordee of the penis), due either to the extent of the haematoma or to the delay in treatment. Traumatic rupture of the corpus cavernosum is a disease of young adults, which requires early surgical treatment with an approach adapted to the type of lesions.     

Maternal serum screening for Down syndrome and neural tube defects

OBJECTIVE: Evaluation of maternal serum screening for Down's syndrome (DS) and neural tube defects (NTDs). DESIGN: Longitudinal study. SETTING: Department of Obstetrics and Gynaecology, University Hospital Utrecht, the Netherlands. METHOD: 6362 pregnant women underwent serum screening for DS and (or) NTD between the 15th and 21st weeks of pregnancy between March 1991 and March 1996. Screening was performed using alpha-foetoprotein, unconjugated oestriol, human chorionic gonadotrophin and maternal age. The result of each individual test was a calculated risk for delivering a child with DS and (or) NTD. RESULTS: Nine out of 12 singleton pregnancies of a foetus with DS were detected. To this purpose, 573 women who, according to the serum screening had an increased risk of a child with the abnormality, were offered amniocentesis, which was performed in 471 of them. Two twin pregnancies with a total of 3 DS affected foetuses were also detected; one twin pregnancy of a DS foetus was screen-negative. The one case of spina bifida was screen-positive. The proportion of women eligible for invasive prenatal diagnosis because of maternal age increased from 9% to 25% in the course of the study. Of 1118 women aged > or = 36 years 913 (82%) declined invasive investigation compared with 40% in the general population. CONCLUSION: The results of the maternal serum screening program in Utrecht were comparable with other studies. Maternal serum screening is accepted as an alternative by women above 36 years, and allows to decrease the need for amniocentesis without a significant loss in detection rate.     

Beta-2 adrenoceptor genetic variation is associated with genetic predisposition to essential hypertension: The Bergen Blood Pressure Study

We tested the hypothesis that genetic variation in the beta-2 adrenoceptor gene is associated with a genetic predisposition to hypertension. Offspring of two hypertensive parents were compared with offspring of two normotensive parents. The subjects were participants of the Bergen Blood Pressure Study, where couples were recruited in 1963 to 1964 and re-examined in 1990. We studied offspring of those couples in which both partners were either hypertensive or normotensive in both examinations. Twenty-three hypertensive and 22 normotensive families met the inclusion criteria. DNA samples from the first born of hypertensive family-history offspring and normotensive family-history offspring were analyzed. We used multiplex sequencing and specifically examined the promoter and the N-terminal portion of the beta-2 adrenoceptor gene. We found four genetic variants: at position -47, a C-->T substitution in the 5' leader cistron causing an Arg-->Cys exchange, at -20, a T-->C substitution, at +46 an A-->G substitution leading to an Arg16-->Gly exchange, and at +79, a C-->G substitution leading to a Gln27-->Glu exchange. The frequency of the Arg16 allele was significantly higher in the hypertensive family-history offspring compared to normotensive family-history offspring (58% vs. 28% P < 0.011). We constructed haplotypes for the four intragenic variants and found significant linkage dysequilibrium. In particular, the 5' leader cistron mutant with the wild type alleles at the other loci was significantly more frequent in offspring of hypertensive parents, compared to offspring of normotensive parents. We also performed a relative risk analysis comparing the Gly/Gly, Arg/Gly, and Arg/Arg alleles, which implicated the Arg-containing allele. Finally, we analyzed the effect of genotype on blood pressure in the offspring. We found a significant step-wise effect for all four polymorphisms examined. Our data suggest that the Arg variant of the Arg-->Gly exchange is associated with parental hypertension and higher blood pressure values in this northern European population.