Infrared analysis of the mineral and matrix in bones of osteonectin-null mice and their wildtype controls.

Osteonectin function in bone was investigated by infrared analysis of bones from osteonectin-null (KO) and wildtype mice (four each at 11, 17, and 36 weeks). An increase in mineral content and crystallinity in newly formed KO bone and collagen maturity at all sites was found using FTIR microspectroscopy and imaging; consistent with osteonectin's postulated role in regulating bone formation and remodeling. Mineral and matrix properties of tibias of osteonectin-null mice and their age- and background-matched wildtype controls were compared using Fourier-transform infrared microspectroscopy (FTIRM) and infrared imaging (FTIRI) at 10- and 7-mm spatial resolution, respectively. The bones came from animals that were 11, 17, and 36 weeks of age. Individual FTIRM spectra were acquired from 20 x 20 microm areas, whereas 4096 simultaneous FTIRI spectra were acquired from 400 x 400 microm areas. The FTIRM data for mineral-to-matrix, mineral crystallinity, and collagen maturity were highly correlated with the FTIRI data in similar regions. In general, the osteonectin-null mice bones had higher mineral contents and greater crystallinity (crystal size and perfection) than the age-matched wildtype controls. Specifically, the mineral content of the newly forming periosteal bone was increased in the osteonectin-null mice; the crystallinity of the cortical bone was decreased in all but the oldest animals, relative to the wildtype. The most significant finding, however, was increased collagen maturity in both the cortical and trabecular bone of the osteonectin-null mice. These spectroscopic data are consistent with a mechanism of decreased bone formation and remodeling.     

Neuronal vacuole formation in the rat posterior cingulate/retrosplenial cortex after treatment with the N-methyl-d-aspartate (NMDA) antagonist MK-801 (dizocilpine maleate)

Cytoplasmic vacuoles appear in neurons of the posterior cingulate/retrosplenial cortex (PC/RS) of rats after treatment with N-methyl-d-aspartate (NMDA) receptor antagonists. Prominent dilatation of mitochondria and endoplasmic reticulum has been described within 2 h; however, the ultrastructural features of vacuole formation are unknown. To investigate this, the present study examined the PC/RS cortex of male rats (age 60–70 days) at 15, 30, 45, 60, 90, and 120 min after subcutaneous treatment with 1 mg/kg of the noncompetitive NMDA antagonist MK-801 (dizocilpine maleate, 5-methyl-10, 11-dihydro-5H-dibenzo [a,d] cyclohepten-5,10-imine). Subtle mitochondrial dilatation was identified in a few neurons as early as 15 min postdose (MPD). By 30 MPD, dilatation was more pronounced in mitochondria and also involved the endoplasmic reticulum and perinuclear space. Ribosomal disaggregation and degranulation were also evident by 30 MPD. At all subsequent time points, dilatation of mitochondria and endoplasmic reticulum progressed in severity. Although the relative involvement of mitochondria and endoplasmic reticulum varied, glia were not involved. These ultrastructural data suggest that after treatment with MK-801, mitochondrial dilatation precedes involvement of endoplasmic reticulum in vacuolization of susceptible PC/RS cortical neurons. The early mitochondrial effects identified in this study suggest an initial metabolic insult that rapidly progresses to affect endoplasmic reticulum and ribosomes. This strengthens the relationship between the ability of certain NMDA antagonists to induce energy perturbations and neuronal vacuoles in the same region of the rat cerebral cortex.     

Growth hormone releasing activity by intranasal administration of a synthetic hexapeptide (hexarelin)

OBJECTIVE Hexarelin is a new synthetic growth hormone releasing peptide. We have tested the efficacy of intranasal (i.n.) administration of hexarelin to stimulate plasma GH and have compared this to the intravenous (i.v.) administration of the peptide. PATIENTS Ten children with familial short stature (FSS) aged 5·5-15·5 years and two known GH deficient patients aged 24 and 28 years without GH treatment. METHODS All 12 subjects were submitted to i.v. (1 μg/kg) and i.n. (20 μg/kg) hexarelin tests with a one-week interval between tests. Blood samples for GH, TSH, fT4 and T3 were obtained at 0, 15, 30, 60, 90 and 120 minutes. The hormone determinations were made by standard radio-immunoassays (RIA). RESULTS Both the i.n. and i.v. administration of hexarelin induced a large GH response, the mean (±SD) being 72·2± 35·5 mU/l for the i.n. test and 79·6 ± 53·0 mU/l for the i.v. test. The peak GH in the i.v. test occurred at 15–30 minutes and in the i.n. test between 30 and 60 minutes. The GH deficient patients showed no GH response In either test. Plasma TSH decreased in the FSS children from a mean (±SD) of 1.0 ± 0·26 to 0·64±0 2 mU/l (P<0 005) during the i.n. test and from 1·0±0·3 to 0·7±0·3mU/l (P> 0 05) during the I.v. test. In the isolated GH deficient patient, plasma TSH decreased from 1·06±0·38 mU/l to 0·86±0·17 during the i.v. test and from 1·60±0·01 to 1·11±0·06mU/l during the i.n. test. There were no significant changes in plasma fT4 or T3 in any of the tests. CONCLUSIONS The synthetic hexapeptide hexarelin is a potent pituitary GH stimulator when administered intra-nasally. The GH response was similar to that observed after intravenous hexarelin. Simultaneously, there was a significant decrease in plasma TSH but the concentrations remained in the normal range. These findings appear to be of theoretical and practical relevance to the investigation and management of short children.     

The Mikulicz Cell in Rhinoscleroma: Light, Fluorescent and Electron Microscopic Studies

The stages in the development of the Mikulicz cell in human rhinoscleroma were studied in biopsy specimens obtained from 10 patients using light, immunofluorescent and electron microscopy. The Mikulicz cell was identified morphologically as a macrophage, not a plasma cell. Acutely inflamed areas of rhinoscleroma presented abundant bacteria with a slime layer. The microorganism was infrequent and the mucopolysaccharide was scanty in rhinoscleromal tissue, where plasma cells predominated, and in cicatricial fibrous tissue. In the granulomatous stage of rhinoscleroma, the mucopolysaccharide was found within the Mikulicz cells. The vacuoles observed in the Mikulicz cells were considered to be phagosomes containing, principally, bacterial mucopolysaccharide and few bacteria and, to a lesser extent, swollen mitochondria. It was concluded that the slime layer of Klebsiella rhinoscleromatis plays an important role in the pathogenesis of the disease. It is postulated that this material is a nondigestible mucopolysaccharide that resides in the phagosomes of macrophages, increases the osmotic pressure and forms multiple hydropic vacuoles that rupture not only the phagosomes but also the cells, resulting in the liberation of the mucopolysaccharide. This would initiate a cycle that would prolong the disease in the absence of the bacteria.     

Cell-mediated immunity in leprosy and transfer of delayed hypersensitivity reactions

Eighty-nine patients with leprosy, 65 classified as lepromatous and 24 as tuberculoid, were examined in this study. Skin test responses to protein antigens and dinitrochlorobenzene (DNCB) were depressed in lepromatous patients compared to controls. Tuberculoid patients did not exhibit a significant depression to microbial antigens, but they showed a definite depression in the ability to be sensitized with DNCB. The transfer of delayed hypersensitivity reactions to tuberculin, trichophytin, and lepromin (Fernandez and Mitsuda reactions) was accomplished in lepromatous and indeterminate leprosy patients using viable lymphocytes from donors presenting positive reactions to these antigens. The lepromin reaction was also transferred to patients with South American blastomycosis and cutaneous leishmaniasis. The positive reactions of adoptive immunity were confirmed by histologic examination of skin biopsies.     

Noninvasive prenatal diagnosis of chromosomal aneuploidies by isolation and analysis of fetal cells from maternal blood

The isolation and analysis of nucleated fetal cells (NFCs) from maternal blood may represent a new approach to noninvasive prenatal diagnosis. Although promising, these techniques require highly accurate separation of NFCs from nucleated cells of maternal origin; the two major problems limiting these techniques are the relative rarity of fetal cells in maternal blood and the need to establish their fetal origin. We now report a novel procedure that has allowed accurate separation of NFCs from maternal cells. The technique reported involves direct micromanipulator isolation of histochemically identified hemoglobin F‐positive nucleated cells to obtain fetal nucleated red blood cells (FNRBCs) of high yield and purity. Using this technique, followed by cell‐by‐cell multicolor fluorescence in situ hybridization (FISH) analysis of purified FNRBCs, we were able to detect some of the most common human aneuploidies (including Down syndrome, Klinefelter syndrome, and trisomy 13) in 33 pregnant women referred for amniocentesis. The procedure used, which can be completed in <72 hrs, produced complete concordance with the results of amniocentesis. We also confirm findings of prior studies suggesting that the number of FNRBCs in maternal circulation is remarkably higher in abnormal pregnancies than in normal pregnancies, especially in women carrying a fetus with trisomy 21. © 2001 Wiley‐Liss, Inc.     

Health-related quality of life following percutaneous coronary intervention during the COVID-19 pandemic

Quality of Life Research - During the COVID-19 pandemic, widespread public health measures were implemented to control community transmission. The association between these measures and...     

Effect of photobiomodulation therapy on the proliferation phase and wound healing in rats fed with an experimental hypoproteic diet

Lasers in Medical Science - Photobiomodulation therapy (PBMT) has been indicated for enforcement on healing skin wounds. This study evaluated the effects of PBMT on the healing of skin wounds...