The development and morphofunctional characteristics of the human lateral pterygoid muscle

Peculiarities of the development of superior and inferior heads of lateral pterygoid muscle (LPM) as well as their micro- and ultramicroscopic structure were studied as related to the temporomandibular joint elements in human fetuses and newborns. As a result, heterogeneity and asynchronism of the development of myogenic elements of certain LPM heads were demonstrated. The process of muscle fibres differentiation in LPM superior head leads to more mature structural organization and runs faster than in the inferior head. By the moment of birth average section area of superior head muscle fibres is significantly higher than the inferior head similar parameter.     

Six-month outcome of critically ill patients given glutamine-supplemented parenteral nutrition

Tetrahydrobiopterin is an essential cofactor required for activity of nitric oxide synthases. Existing evidence suggests that, during activation of constitutive and inducible isoforms of nitric oxide synthase, tetrahydrobiopterin is needed for allosteric and redox activation of enzymatic activity. However, precise mechanisms underlying the role of tetrahydrobiopterin in regulation of nitric oxide formation is not fully understood. In cerebral and peripheral arteries, increased availability of tetrahydrobiopterin can augment production of nitric oxide. In contrast, in arteries depleted of tetrahydrobiopterin, production of nitric oxide is impaired. Proinflammatory cytokines enhance mRNA expression of the rate-limiting enzyme of tetrahydrobiopterin biosynthesis, GTP cyclohydrolase I and stimulate production of tetrahydrobiopterin. The ability of vascular tissues to synthesize tetrahydrobiopterin plays an important role in regulation of nitric oxide synthase under physiological conditions as well as during inflammation and sepsis. More recent studies concerning expression and function of recombinant nitric oxide synthases suggest that availability of tetrahydrobiopterin is important for production of nitric oxide in genetically engineered blood vessels. In this review, mechanisms regulating availability of intracellular tetrahydrobiopterin and its role in control of vascular tone under physiological and pathological conditions will be discussed.     

A high deuterium abundance at redshift z = 0.7

Of the light elements, the primordial abundance of deuterium relative to hydrogen, (D/H)p, provides the most sensitive diagnostic for the cosmological mass density parameter, omegaB. Recent high-redshift D/H measurements are highly discrepant, although this may reflect observational uncertainties. The larger primordial D/H values imply a low omegaB (requiring the Universe to be dominated by non-baryonic matter), and cause problems for galactic chemical evolution models, which have difficulty in reproducing the steep decline in D/H to the present-day values. Conversely, the lower D/H values measured at high redshift imply an omegaB greater than that derived from 7Li and 4He abundance measurements, and may require a deuterium-abundance evolution that is too low to easily explain. Here we report the first measurement of D/H at intermediate redshift (z = 0.7010), in a gas cloud selected to minimize observational uncertainties. Our analysis yields a value of D/H ((2.0 +/- 0.5) x 10[-4]) which is at the upper end of the range of values measured at high redshifts. This finding, together with other independent observations, suggests that there may be inhomogeneity in (D/H)p of at least a factor of ten.     

Tracing the spread of methicillin-resistant Staphylococcus aureus by Southern blot hybridization using gene-specific probes of mec and Tn554

In a community hospital in Brooklyn, New York, over a 3-year period, 79 methicillin-resistant Staphylococcus aureus (MRSA) isolates from five different case clusters were subtyped by Southern blot hybridization with two previously characterized gene probes, mec and Tn554. Together, the genotyping enabled the hospital infection control team to differentiate simultaneous MRSA clusters in the surgical intensive care unit (type I:A) and the open heart unit (type II:J), document the spread of one strain (type I:A) between roommates, identify an endemic strain (type II:J) from cardiac monitors and medical personnel, and identify an unrelated outbreak strain (type II:NH) in the labor and delivery unit. On the basis of this investigation it is clear that the routine DNA fingerprinting of MRSA in health care facilities, to monitor their spread and identify cases of nosocomial infections, is an important infection control measure.     

Changes in drug-metabolizing enzymes of rats in ciprofibrate-induced hepatic nodules

1. Premalignant rat liver nodules produced in the resistant hepatocyte model, by exposure to carcinogenic chemicals (diethyl nitrosamine and 2-acetamidofluorene), and partial hepatectomy, exhibit decreased xenobiotic hydroxylase activities and increased conjugase activities, which are considered responsible for increased resistance to xenobiotic toxicity. 2. However, premalignant rat liver nodules generated by feeding the hypolipidaemic, peroxisomal proliferating drug, ciprofibrate, in a hypolipidaemic model, exhibit decreased hydroxylase activities but decreased conjugase activities also. 3. It is considered that reactive oxygen species (ROS) are generated in both the resistant hepatocyte model and in the hypolipidaemic model, resulting in lipid peroxidation, loss of haem, cytochromes and hydroxylase activities. 4. However, whereas there is a rebounding compensation of conjugase enzymes in the resistant hepatocyte model, this does not occur with the hypolipidaemic model, as peroxidation is probably persistent and the conjugases are continuously destroyed.     

Influence of energy supplementation on grazing ruminants: requirements and responses

Energy requirements of grazing livestock seem to be poorly defined. Requirements generated from measurements in pen-fed animals present both theoretical and practical concerns when they are applied to grazing situations. In mature ruminants a majority of energy used for maintenance seems to be consumed by visceral tissues. Moreover, factors that affect visceral energy use are poorly understood. Energy supplementation to meet requirements and production demands is often practiced during periods of summer dormancy and in winter months. Source of supplemental energy varies widely and includes grains, readily digestible fiber sources, and high-quality forages. Intake and digestibility can be reduced or unaffected by energy supplementation. In some cases, lower levels of energy supplementation have been shown to increase utilization of grazed forage. Reductions in ruminal pH, often cited as the major cause of reduced fiber digestion, may not always explain reductions in intake and digestibility associated with energy supplementation. Livestock production is usually either enhanced or unaffected by energy supplementation. Additional research regarding energy requirements of grazing ruminants, visceral energy use, and mechanisms associated with reductions in intake and digestibility of grazed forage resulting from energy supplementation is warranted.     

Comparative studies of the mitogenic effects of epidermal growth factor and transforming growth factor-alpha and the expression of various growth factors in neoplastic and non-neoplastic prostatic cell lines

Murine acute myeloid leukemia is characterized by chromosome 2 aberrations, and genesis of the marker chromosome 2 by radiation is suspected to be an initiating event of radiation leukemogenesis. A detailed analysis of the type and frequency of chromosome 2 aberrations in murine bone marrow cells at an early stage after irradiation is provided here. A total of 40 male C3H/He mice was exposed to 137Cs gamma-ray at a dose of 1, 2 or 3 Gy, and sacrificed 24 hours after irradiation. Metaphase samples prepared from bone marrow cells were Q-banded for karyotyping or painted with DNA probes specific to chromosome 2. In 5 mice analyzed by karyotyping, one mouse showed high frequency of the marker aberrations as well as other chromosome 2 aberrations. Chromosome painting analysis for the rest of the mice also detected 3 animals showing significantly high frequencies of chromosome 2 aberrations. Dose-dependence of the frequencies was observed even among those mice that tended to be sensitive. The results indicated that there was a subgroup of mice carrying hypersensitive chromosome 2. The subgroup could be leukemia-sensitive if radiation-induced chromosome aberrations are responsible for an early change in myeloid leukemogenesis.