Ultrastructure of ischemic contracture of the left ventricle ("stone heart")

Myocardial biopsies from two patients who had developed "stone heart" (myocardial rigor mortis; ischemic contracture of the left ventricle) were studied by electron microscopy. The ultrastructure of tissue in stone heart, though ischemic in nature, differed from that of classic myocardial infarction in some respects. Apart from depletion of glycogen and distension of the sarcoplasmic reticulum and T-tubules, myofibrillar degeneration was much more widespread. Mitochondrial degeneration with active lysosomal autodigestion, disruption of the microcirculation, and lymphedema were prominent changes also observed. In the light of known clinical and experimental observations, our findings suggest that stone heart is an accelerated form of ischemic injury occurring in vulnerable (hypertrophied) hearts and is probably related to ischemia-triggered release of endogenous catecholamines.     

What do children value in entertainment programs? A cross-cultural investigation

We investigated which program characteristics in children's entertainment television programs children between 6 and 11 years of age value. We collected data by means of questionnaires among 100 Dutch and 100 U.S. first through fourth graders. The most important characteristics for both Dutch and U.S. children were comprehensibility and action, closely followed by humor, interestingness, innocuousness, realism, violence, and romance, respectively. Compared to Dutch children, U.S. children attached more value to realism, innocuousness, and interestingness. Boys in both samples attached more value to action and violence in a children's program, whereas girls in both samples attached more value to innocuousness and comprehensibility.     

The development of a model to estimate the bistatic transmissionloss associated with intersystem interference

This paper presents a new method for evaluating transmission loss, which is a key factor used in determining the impact of interference between terrestrial radio relay systems and Earth-satellite systems operating at the same frequency. The current model used by the CCIR was developed in the early 1970's when system packing density was low and large earth station antennas allowed the consideration of narrow beam approximations, resulting in a small common volume of intersection of the two beams. The recent increase in microwave communications traffic and improvements in technology have meant that smaller earth station antennas, including very small aperture terminals (VSATs), can be employed and hence the model requires revision. Results from the new model proposed are compared with two experimental geometries and good agreement is found     

Macromolecules of the central nervous system and acoustic priming in C57BL/6Bg mice

Short-term cultures of androgen-responsive Shionogi 115 (S115) cells exhibited density-dependent regulation of proliferation rate in the presence or absence of testosterone. The average surface area per cell exposed to the growth medium was inversely proportional to population density. By contrast, long-term cultures (serially passaged in testosterone-containing medium for several months) did not exhibit density-dependent regulation of proliferation rate when grown in testosterone-containing medium. In this medium, cells became elongated and no longer exhibited any obvious decrease in exposed surface area with increasing density. Nevertheless, when subcultured into testosterone-free medium, these cells reverted to an epithelial morphology and exhibited density-dependent regulation of proliferation rate. These relationships suggested that the proliferation rate of cells decreased with density in proportion to the decrease in exposed surface area...     

A possible mechanism of Leptaden action by inhibiting prostaglandin F2alpha synthesis

Forearm skin blood flow was measured during external pressure loading in normal human subjects using 133Xe washout from intracutaneous injection sites. Pressures ranging between 5 and 150 mmHg were applied through a 3-cm-diameter disc placed over the site of flow determination. The pressure was maintained constant by a servo-controlled loading mechanism. Flow decreased with pressures from 5 to 10 and 30 to 150 mmHg, but remained constant with pressures from 10 to 30 mmHg. Reactive hyperemia occurred following removal of pressures of 90 mmHg or greater, but did not occur following removal of lower pressures. The pressure-flow curve for parasacral skin of paraplegic subjects closely paralleled the pressure-flow curve of normal skin at pressures tested: 5-15 mmHg. These data are interpreted to demonstrate autoregulation of skin blood flow. Autoregulation in parasacral skin of paraplegic subjects suggests a peripheral mechanism. The occurrence of hyperemia at pressures which exceed the ability of skin to autoregulate suggests that both autoregulation and post occlusion hyperemia may have the same mechanism.     

Osteopetrosis in the IA rat cured by spleen cells from a normal littermate

The Clausen modification of the peripheral blood buffy coat leukocyte migration test was used to test patients with multiple sclerosis, normal subjects and patients with other neurologic diseases for cell-mediated immunity to commercial measles virus, purified nuclear core material from a human neurotropic strain of measles virus, as well as to commercial preparations of rubella, mumps and parainfluenza HA2. Leukocytes of multiple sclerosis patients showed significantly less mean inhibition of migration in the presence of both measles antigens, mumps and parainfluenza but no difference from controls when incubated with rubella. No correlation could be found between the degree of migration inhibition and concomitant serum anti-measles neutralization antibody titers to the same strain of virus. The use of purified viral antigens might result in more meaningful studies of the status of cellmediated immunity to viral antigens in multiple sclerosis. The relationship of our findings to other studies in this area and to the pathogenesis of multiple sclerosis is discussed.     

A highactivity ATP translocator in mesophyll chloroplasts of Digitaria sanguinalis, a plant having the C-4 dicarboxylic acid pathway of photosynthesis

The effect of exogenous adenine nucleotides on CO2 fixation and oxygen evolution was studied with mesophyll protoplast extracts of the C4 plant Digitaria sanguinalis. Exogenous ATP was found to stimulate the rate of pyruvate and pyruvate+oxalacetate induced CO2 fixation, as well as reverse the inhibition of CO2 fixation of carbonyl cyanide m-chlorophenyl hydrazone and several electron transport inhibitors. The ATP-dependent stimulation of CO2 fixation varied from 40 to 70 mumol CO2 fixed/mg chlorophyll per h, suggesting that ATP was crossing the chloroplast membranes at rates of 80-140 mumol/mg chlorophyll per h, since 2 ATP are required for each CO2 fixed. Fixation of CO2 could also be induced in the dark by exogenous ATP, in which case ADP accumulated outside the chloroplasts...     

Effect of bromo-ergocryptine on serum hPRL, hLH, hFSH, and estradiol 17-beta in women with galactorrhea-amenorrhea

Fourteen women with amenorrhea-galactorrhea were treated with bromo-ergocryptine. Serum prolactin hPRL, hLH, hFSH, estradiol 17-beta (E2), and progesterone values were determined before and during treatment. No consistent pretreatment hormonal pattern was found. During treatment hPRL levels fell in 13 of 14 patients, and E2 rose in 12 of 14 patients. Levels of hLH became normal, and amounts of hFSH did not change. Galactorrhea lessened in all cases and ceased in 11. Menses resumed in 11 patients and 3 women became pregnant. Cessation of galactorrhea and resumption of menses occurred irrespective of initial hPRL or hLH levels. It is suggested that improvement of galactorrhea and resumption of menses in some patients with normal hPRL values are the result of increased serum E2 levels and may be due to a direct action of bromo-ergocryptine on the ovary. Bromo-ergocryptine may also be effective in treatment of amenorrhea, unassociated with galactorrhea or elevated hPRL levels.