Severe right ventricular outflow tract obstruction caused by an intracavitary cardiac neurilemoma: succesful surgical removal and postoperative diagnosis

A 32-year-old woman with a one-year history of progressive shortness of breath and chest pain was found to have a grade 4/6 systolic murmur at the base of the heart and left sternal border. Right ventricular enlargement was found by physical examination, ECG, and chest roentgenogram. Cardiac catheterization showed elevated right ventricular pressure, an intracavitary pressure gradient, and inability to enter the pulmonary artery. Angiography revealed a mass in the right ventricular outflow tract. Successful surgical removal of a large, well-encapsulated tumor mass was accomplished, and the tumor was interpreted as a benign neurilemoma. Postoperatively, the patient improved remarkably.

Observations on thyroid hormones in the blood of thoroughbreds

During an investigation of a group of clinically well thoroughbreds housed in the same stable, it was noted that seven of the 14 had no detectable thyroxine in the plasma (less than 5 nmol/litre). An investigation of thoroughbreds in this stable over a five month period suggested that the thyroids were functioning normally and that the thyroxine was excreted in the urine. Thyroxine binding studies on the blood of these horses suggested that the major part of the circulating thyroxine was bound to albumin. The thyroxine had been displaced resulting in an apparent absence of plasma thyroxine since the limit of detection for normal radioimmunoassay is 5 nmol/litre. It is concluded that the measurement of plasma thyroxine as an indication of thyroid function in the thoroughbred can prove unreliable.

The use of gene frequencies in estimating the mean number of mates in a multiple-mate and stored-sperm system of mating

As is the case with single-mate systems, random mating within a multiple-mate and stored-sperm system of mating generates a number of predictable mate-encounter patterns. Under a random matingmodel, the proportions of homozygous recessive females producing offspring in the distinct classes: i) dominant only, ii) dominant and recessive, and iii) recessive only, are shown to be a function of the mean number of matings per female. Accordingly, the validity of hypothesized mean numbers of matings per female may be tested through a comparison of observed and expected genotypic distributions. A number of mate-encounter patterns have low expected frequencies and may even fail to occur without producing significant changes in gene frequencies.

Pseudomonas aeruginosa bacteremia in a dialysis unit. 11. Relationship to reuse of coils

Blood for culture was obtained over a six week period from 17 patients undergoing long-term hemodialysis. Bacteremia was detected during 18 of 201 dialyses. Blood drawn during fifteen of these dialyses contained pseudomonas aeruginosa. Ten of the 17 patients (59 per cent) had a Pseudomonas bacteremia some time during the study. Only one patient was symptomatic. The frequency of positive cultures was related to reuse of coils. No cultures were positive until after the fifth use, but by the tenth use, 41 per cent of the dialyses were associated with bacteremia. All coils that were used repeatedly and 32 of 48 of those used only once, grew Ps. aeruginosa when filled with media and incubated. This suggests that the coils were inoculated during dialysis and that benzalkonium chloride, the sterilizing agent, was unable to eradicate this organism. With repeated uses, the number of residual bacteria in the coil became large enough to cause detectable bacteremia during dialysis.

Age-associated structural alterations in senescent mouse brain DNA

The maintenance of structural integrity in the DNA of aging mice has been examined with the amin in view of determining whether changes in genome structure constitute the molecular basis of aging. Cell lysate DNA from brains of differently aged mice was subjected to alkaline sucrose gradient sedimentation. The results show that brain DNA from young mice sediments mondispersely while that from senescent mice exhibits polydisperse sedimentation patterns, bainding in four peaks corresponding to number-average molecular weights of 1.4-10(8), 70-10(6), 15-10(6) and 3-10(6). When treated with nuclease S1, it was the 30 month mouse DNA whose sedimentation shifted to the top of the gradient indicating a reduction in its molecular weight as a result of nuclease digestion. The apparent increase in single strand breaks implies that the rate of breakage in old mouse brain DNA is faster than that of repair replication. The conclusion is drawn that senescence could result from an accumulation of defects in the genome.

On the birth of an infant with sickle cell anemia

This is the first report in the English literature of the birth of an obligate SS infant whose parents both had sickle cell anemia. The young adult SS parents of this infant and their families did not wish to prevent the birth of this child but had, in fact, many positive reasons to continue the pregnancy to term even in the face of the increased personal risk of pregnancy for this mother. This unusual circumstance initiated a re-appraisal of the realistic expectations with respect to reproduction in patients with homozygous recessive genetic disorders. No definitive studies could be found which attempted to evaluate the influence of genetic counseling on reproductive behavior in patients with sickle cell anemia. The questions raised about the 'right to reproduce' and the realistic aims of genetic counseling in adult homozygote patients have been discussed. However, no conclusions seem warranted because of the paucity of available information.

Human red cells protein kinase in normal subjects and patients with hereditary spherocytosis, sickle cell disease, and autoimmune hemolytic anemia

A somewhat simplified modification of a previously described method for the measurement of red cell membrane phosphorylation by ATP has been devised. Phosphorylation of membranes was linear with time for only 5-10 min, and linearity with membrane concentration was observed only when assays were limited to short incubation times. Protein kinase activity of hereditary spherocytosis (HS) membranes was found to be normal. However, the average phosphorylation after 60 min incubation was less in HS membranes than in normal membranes. Findings similar to those in HS membranes were observed in sickle cell disease. The Km of red cell protein kinase for ATP is approximately 10(-5) M. Membrane phosphate binding sites are not saturated in either HS or normal membranes after 1 hr incubation with ATP. Approximately 27% of phosphorylating activity is lost after 1 hr incubation at 37 degrees C. GTP is a very inefficient phosphate donor. Under the conditions of measurement employed, the enzyme is slightly stimulated by 1 muM cAMP, but is not stimulated by 1 muM cGMP. Dephosphorylation of red cell membranes after labeling occurs at a similar rate in HS as in normal membranes. Although a mild abnormally in membrane phosphorylation is observed in HS, this could not be demonstrated to be due to a decrease in protein kinase activity or in alterations of its kinetic properties. The abnormally seen is not specific for HS.

Raman pH profiles for nucleic acid constituents I. Cytidine and uridine ribonucleosides

Raman spectra of aqueous solutions of uridine and cytidine have been recorded as a function of pH with the band intensities and vibrational frequencies monitored to determine bands which may be considered as diagnostic of the concentration of the various species. Quantitative band intensity measurements indicate that not all pH-sensitive bands can be considered as diagnostic of the pK value for the acid form of the nucleoside, and for the percent species in solution. Although the accuracy of the Raman band intensity method is inherently less than that of the titrimetric or visible-ultraviolet spectrophotometric methods, the pK values and percent species agree well with those obtained from these methods. The utility of the results obtained from the pH profiles for cytidine is discussed in terms of the effect of acidification on the structural and conformational characteristics of polycytidylic acid in solution.

Raman ph profiles for nucleic acid constituents. II. 5'-AMP and 5'-GMP ribonucleotides

Raman spectra of aqueous solutions of 5'-AMP and 5'-GMP have been recorded as a function of pH. Band intensities and frequencies have been monitored to determine bands which may be considered as diagnostic for the concentration and the pK of the solution species. Quantitative band intensity measurements indicate only a selected number of bands can be considered as diagnostic of the base or the secondary phosphate proton dissociation. The utility of the pH profiles derived from specific band intensity variations for 5'-AMP is discussed in terms of the effect of acidification on solution characteristics of polyadenylic acid.

Diffuse reflectance from a finite blood medium: applications to the modeling of fiber optic catheters

The scattering and absorption of light by randomly oriented, discretely scattering, red blood cells imbedded in a homogeneous plasma medium can be described by the P1 approximation to the one-speed transport equation, where the cells have the dual role of anisotropic sources for first scattering events and of scattering and absorption sites for subsequent scattering events. Equations for diffuse reflectance defined for a finite size receiver in the plane of a normally incident cylindrical photon beam are derived and compared with experimental data to fundamentally justify the basic sending-receiving characteristics of a fiber optic catheter model. A model of the fiber optic catheter used for the spectrophotometric measurement of oxygen content in blood is developed from the theory and compared with experimental results to further substantiate the theoretical approach.

Genetics of red body polymorphism in the isopod, Venezillo evergladensis

A red body morph with reddish-orange body and brownish-red eyes is described in the terrestrial isopod, Venezillo evergladensis. The alternate, non-red morph, has a brown body and black eyes and either gray or orange antennae. Breeding results show three alleles, rg, ro and r at an autosomal locus control the variation. The dominance hierarchy is rg less than ro less that r; the genotypes, rg/rg, rg/ro, and rg/r are non-red, grey, ro/ro and ro/r are non-red, orange, and r/r are red. The gray antennae of non-red, gray individuals is variable in expression although still objectively recognized. The red body morph and its inheritance is paralleled in related species, while the antennal variation identifies a new allele. Sperm storage, exceeding a full year, and multiple matings in nature are documented.