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Biomedical subjects

R J Moore

Publications and source records attributed to R J Moore.

At least 91 records · Page 5Linked to original sources
PubMed1992

A scanning electron microscopic study of rete ridges in the cheek pouch of normal young, adult and aged Syrian hamsters.

Cheek pouches were removed from BIO 87.20 male hamsters 4 weeks, 8 months or 18 months of age. One pouch from each animal was routinely processed for light microscopy. The epithelium and connective tissue of the remaining pouches were separated with EDTA and routinely processed for scanning electron microscopy. Two types of rete ridge were found: simple, consisting of a single epithelial ridge or blunt projection and complex, made up of multiple interconnecting ridges. The simple type predominated at 4 weeks (90%) but the complex type predominated at 8 (58%) and 18 months (73%). Although the 8- and 18-month pouches were significantly larger than the 4-week ones, the total number of rete ridges was similar at all ages. This, taken in association with the shift in type with age, suggests that the simple rete ridges develop into the complex ones. With increasing age more of the complex rete ridges took on the characteristics of touch domes. These changes in the shape of the rete ridges with age need to be taken into account in studies on experimentally altered cheek pouches so that they are not mistaken as pathological changes.

Aging↗
PubMed1992

Effects of oophorectomy on biochemical and bone variables in the rat.

The metabolic effects of oophorectomy (Oophx) were studied in 6-month-old rats maintained on a normal chow diet. Nine weeks following operation, Oophx animals had a significantly lower femoral trabecular bone volume (BV/TV) than sham-operated animals; mean (SD) Oophx 8.5 (3.8)%; Sham 13.4 (2.5)%; P = 0.013). They also had a higher urine hydroxyproline (P less than 0.001), serum alkaline phosphatase activity (P less than 0.001), serum phosphate (P less than 0.001) and lower serum albumin (P less than 0.001) than the controls. Serum osteocalcin was inversely related to the BV/TV in the Oophx animals at 9 weeks post operation (r = -0.85, P = 0.007, n = 8). A fall in serum ionized calcium from 3 to 9 weeks post operation correlated with a fall in urinary hydroxyproline in the Oophx animals (r = 0.57, P = 0.002, n = 27). The data are consistent with a model of ovarian hormones acting directly to modulate bone cell activity as well as exerting an effect on the renal handling of phosphate.

Alkaline Phosphatase↗
PubMed1992

Comparative study of iliac crest and subchondral femoral bone in osteoarthritic patients.

This is a study of trabecular bone changes in selected regions of the femoral head. Iliac crest bone from osteoarthritic (OA) and control groups is compared to the bone from regions in the femoral head. The regions are the subchondral principal compressive and tensile areas. These areas of highest and lowest stress undergo dramatic change with OA. The compressive region has total cartilage loss and eburnation. Bone histomorphometry was done on undecalcified tissue sections stained by the von Kossa silver method and counter-stained with haematoxylin and eosin. Iliac crest histomorphometry is similar for the OA and control groups. The femoral trabecular structure in the stress regions changes in opposing directions with OA. In the compressive region the structural variables (BV/TV and BS/TV) increase [corrected], and in the tensile region decrease. Femoral bone turnover indices (OV/TV, OS/BS, and ES/BS) are no different, but femoral bone structure is different from that of the iliac crest. In OA patients there is no significant increase in iliac crest trabecular bone volume. The iliac crest is not useful to assess the bony changes in femoral OA.

Aged↗
PubMed1992

Changes in endplate vascularity after an outer anulus tear in the sheep.

In 31 2-year-old sheep, a 5-mm deep cut was made parallel to the end plates in the left anterolateral anulus fibrosus of 3 randomly selected lumbar intervertebral discs. At 2 months, the area of the end plate occupied by blood vessels on the left (operated) side had increased significantly (P less than 0.05) in the cranial end plate to 9.94%, and to 9.39% in the caudal end plate, compared with nonoperated values of 5.17% (cranial) and 5.87% (caudal). One year after operation, these elevated values had diminished significantly (P less than 0.05) to 7.92% (cranial) and 7.13% (caudal), and continued to decline progressively to 7.48% (cranial) and 6.88% (caudal) by 2 years. In contrast, no significant differences were found on the right (nonoperated) side of the discs. Thus, there was an early proliferation of vascular channels in the end plate in the vicinity of the experimental anular lesion, but not on the nonoperated side of the same disc. Thereafter, the end plate vascularity progressively diminished toward a normal level.

Animals↗
PubMed1992

Trabecular spacing in post-menopausal Australian women with and without vertebral fractures.

Histomorphometric measurements were made from iliac crest biopsies of 32 women with vertebral fractures and 37 women without fracture. All were post-menopausal Australian women who had presented with back pain to a hospital out-patient endocrinology clinic. Bone from the fracture cases was characterised by loss of individual trabecular elements, with the remaining trabeculae being spaced further apart than those in the non-fracture women (p less than 0.0001). This resulted in a significant decrease in trabecular bone volume (p less than 0.01). In addition osteoid surface was reduced (p less than 0.01). Dynamic parameters of bone turnover were not significantly different between the two groups. These data should be useful for the assessment of iliac bone histomorphometry in Australian post-menopausal women suspected of having osteoporosis.

Aged↗
PubMed1991

Promoting blood donation: a study of the social profile, attitudes, motivation and experience of donors.

This study investigated how to improve the recruitment of blood donors, their retention as active donors and their response to call-up. A total sample of 9,000 non-donors, lapsed donors and current donors was examined in three programmes to determine the sex, age and social profile of donors; the attitudes of the population to blood donation; the motivating forces prompting people to give blood; the de-motivating forces preventing them; the image of the blood donor in society and the image of the National Blood Transfusion Service (NBTS). The profile of blood donors, with small variations, reflects that of the population. The experience of blood donation is widespread with 27% of the population either current or lapsed donors. The image of both blood donors and the NBTS was found to be very positive. The main force motivating donors is an awareness of patient need complemented by awareness that the need may one-day be personal. NBTS strategy will concentrate on reinforcing the need for blood donors and enhancing the experience of donors at blood donor sessions.

Adolescent↗
PubMed1990

The use of amphipathic maleimides to study membrane-associated proteins.

A series of amphiphilic polymethlyenecarboxymaleimides has been synthesized for use as sulfhydryl reagents applicable to membrane proteins. Physical properties of the compounds which are relevant to their proposed mode of action have been determined. By comparing rates of reaction in aqueous and aprotic solvents, the compounds have been shown to react exclusively with the thiolate ion. The effects of the reagents on three membrane-associated proteins are reported, and in two cases a comparative study has been made of the effects on the proteins in the absence of membranes. A mechanism is proposed whereby the reagents are anchored at the lipid/water interface by the negatively charged carboxyl group, thus sitting the reactive maleimide in a plane whose depth is defined by the length of the reagent. Supporting evidence for this model is provided by the inability of the reagents to traverse membranes, and variation of their inhibitory potency with chain length when the proteins are embedded in the membrane, but not when extracted into solution. As examples of general use of the reagents to probe sulfhydryl groups in membrane proteins, the reagents have been used to (a) determine the depths in the membrane at which two populations of sulfhydryl groups occur in the mitochondrial phosphate transporter; (b) locate a single sulfhydryl associated with the active site of D-beta-hydroxybutyrate dehydrogenase in the inner mitochondrial membrane; (c) examine sulfhydryl groups in the D-3-glyceraldehyde phosphate dehydrogenase associated with the human red blood cell membrane.

Animals↗
PubMed1990

Progressive cancellous bone loss in rats after adrenalectomy and oophorectomy.

Female Sprague-Dawley rats (n = 72), 6 months old, underwent either sham operation, oophorectomy, adrenalectomy, or combined oophorectomy and adrenalectomy (O&A). They were all maintained on normal saline ad libitum and 20 g/day 1.1% calcium chow. Nine weeks after operation, the trabecular bone volume of the distal femoral shaft was significantly lower (P less than 0.001) in the adrenalectomized (11.1%), oophorectomized (7.0%), and O&A (8.3%) animals than in sham-operated animals (19.8%). Eighteen weeks after operation, the trabecular bone volume in O&A animals had fallen to a mean of 3.8% (sham 17.0%), and the length of the femur had increased to 38.8 mm after O&A (sham 36.8 mm, P less than 0.01). O&A animals treated with 0.35 mg/kg/week nandrolone decanoate from 9 weeks postoperatively onward, had twice the femoral trabecular bone volume of untreated animals at 18 weeks (P less than 0.05). By contrast, no significant differences were found in vertebral body trabecular bone between any groups, including groups receiving treatment with androgens. We have found that, by 9 weeks after operation, adrenalectomy alone causes significant loss of metaphyseal trabecular bone, similar to the progressive loss seen after oophorectomy.

Adrenal Glands↗
PubMed1990

Beer mitigates some effects of copper deficiency in rats.

Because of an epidemiologic association of decreased risk of death from ischemic heart disease with moderate use of alcoholic beverages, and because numerous abnormalities found in people with ischemic heart disease are also found in animals deficient in copper, rats were fed a diet deficient in copper and were given either beer or water to drink. Rats drinking beer lived nearly six times as long and had lower plasma cholesterol, less cardiac enlargement, and higher liver copper. Apparent absorption and biological half-life of oral radiocopper were increased by beer. The effects were not attributable to alcohol, chromium, or copper in beer. Beer intakes were similar to those of some people in the United States. Results may explain seasonal cycles in plasma cholesterol and may be germane to the epidemiology of ischemic heart disease because diets in the United States seem to be low in copper.

Animals↗
PubMed1989

Comparison of two bone trephine instruments used for quantitative histomorphometry.

Transilial bone samples were obtained at necropsy using trephine instruments with internal diameters of 2 mm and 7 mm. Undecalcified histological sections were prepared and two structural histomorphometric variables (percentage of trabecular bone volume and surface density of bone) were estimated by a Quantimet 720 image analyser. The differences between the variables measured from the two adjacent cores were due to differences in biopsy site rather than the size of the sample. The smaller diameter needle is therefore recommended for use as the biopsy procedure is simpler and tissue sections can be prepared sooner than is the case with the larger needle.

Adult↗
PubMed1989

Comparative study of iliac crest and proximal femur histomorphometry in normal patients.

The relation between the bone histomorphometric profile of the iliac crest and regions of the proximal femur was investigated. In the proximal femur four blocks were selected, representing the subchondral principal compressive (SPC) and tensile (SPT) regions, the zone near the medial cortex in the principal compressive region (MPC), and the zone medial to the greater trochanter (MGT). Undecalcified tissue sections stained by the von Kossa silver method and counterstained with haematoxylin and eosin were used for quantitation. The SPT region was most representative of the iliac bone profile, in particular the structural parameters of mineralised bone, trabecular thickness, and trabecular spacing and resorption surface. Most parameters in the regions studied showed inconsistent and variable results when compared with those of the iliac crest. There was only a weak association, therefore, between the histomorphometric parameters of the iliac crest and the proximal femur despite the appeal of the use of the iliac biopsy specimen as a simple clinical test.

Adolescent↗
PubMed1989

Variation in histomorphometric estimates across different sites of the iliac crest.

Bone specimens were obtained from four different sites in the ilium of necropsy cases using a Jamshidi 8G trephine needle. Undecalcified histological sections were prepared and two structural histomorphometric parameters were estimated. Estimates of the percentage of trabecular bone volume (%TBV) deviated systematically, with variation of the biopsy site around the usual location, increasing in magnitude from the anterior to the posterior ilium. Such differences highlight the importance of understanding the degree of variation which exists in histomorphometric data. The histomorphometry of a vertical biopsy specimen of the iliac crest did not differ significantly from that of a transilial biopsy specimen of similar diameter taken from an adjacent site. When taken at the standard site, and when providing a long core of cancellous bone, with minimal discomfort to the patient, the vertical biopsy specimen compares well with the transiliac biopsy specimen for use for investigating metabolic bone disorders.

Adult↗
PubMed1989

Acute renal failure and fluid retention and kidney damage in copper-deficient rats fed a high-NaCl diet.

The effect of an interaction between Cu status and dietary NaCl level on kidney structure, water balance, and the plasma renin-angiotensin-aldosterone system (RAAS) was examined in 64 male Sprague-Dawley rats (178 gm) fed a copper-supplemented diet (CuS) (10 micrograms Cu per gram) or a copper-deficient diet (CuD) (less than 0.7 micrograms Cu per gram), with (CuSNa, CuDNa) or without 3% NaCl for 42 days. NaCl did not affect growth, fluid retention, or kidney ultrastructure in Cu-supplemented rats. Cu deficiency decreased growth rate and kidney Cu, increased plasma cholesterol concentration, and suppressed plasma RAAS. NaCl increased the magnitude of these changes in Cu-deficient rats. The mortality rate was higher in CuDNa (8/16) than in Cu-deficient (2/16) rats. An acute renal failure syndrome characterized by tissue edema, pleural effusion, and ascites occurred in rats fed CuDNa. Bioelectric impedence analysis indicated that body water content was similar in rats fed CuS, CuSNa, and CuD but was higher in edematous and nonedematous rats fed CuDNa. Transmission electron microscopy indicated that glomeruli from Cu-deficient rats were poorly perfused and often occluded by expanded mesangium and contained numerous lysozome-like bodies. Fusion of podocyte foot processes, derangement of glomerular basement membrane, and hypertrophy and lipid accumulation by glomerular capillary endothelium were present in tissue from rats fed CuDNa. These results indicate that Cu deficiency reduces NaCl tolerance in rats. Ultrastructural changes in kidney tissue and the suppression of RAAS in rats fed CuDNa suggest that the edema and ascites result from acute renal failure and not from increased fluid and electrolyte reabsorption.

Acute Kidney Injury↗
PubMed1988

Growth, nutrient utilization and intestinal morphology of pigs fed high-fiber diets.

Two trials (24 and 48 pigs; 9.7 kg initial body weight) were conducted to determine the effects of dietary fiber on growth, nutrient utilization and intestinal morphology of young pigs. The four diets fed were: basal corn-soybean meal (B), 15% oat hulls (OH), 15% soybean hulls (SH), and 20% alfalfa meal (AM). Fiber source did not have major effects on performance in a 35-d feeding trial. Balance trials (7-d duration) were conducted 32 d (Trial 1) or 6 d (Trial 2) after completion of the feeding trials. Feed intakes were equalized at 8.7% (Trial 1) or 10.3% (Trial 2) of initial body weight (kg.75). All fiber sources decreased apparent digestibilities of N, energy and dry matter (P less than .05) with no effect on N retention. Apparent digestibilities of neutral and acid detergent fiber, cellulose, and hemicellulose were reduced by OH and AM (P less than .01), but not by SH. Fiber sources did not affect apparent Ca, P, Zn or Mn absorption or retention, or Mg absorption, but decrease Mg retention (P less than .05). Apparent Na absorption was decreased by OH and increased by AM (P less than .05) but was unaffected by SH. All fiber sources increased K intake, but only SH and AM increased apparent K absorption (P less than .05). Fiber sources did not affect Na or K retention. The OH increased Cu intake and balance (P less than .05). All fiber sources increased Fe intake, but only SH and AM increased (P less than .05) Fe balance. Villus shape and surface morphology in jejunum and ileum examined by scanning electron microscopy (Trial 1 only) appeared to be independent of diet. However, jejunum villus morphologies of two pigs fed AM were characterized by loss of epithelial cells and microvilli at the villus apex, and ileum villi were blunted and frequently folded in one pig fed SH. Fiber sources at the levels included in a corn-soybean meal diet fed in this study had only a minimal impact on performance and utilization of minerals and N and intestinal structure, although apparent energy utilization was decreased.

Animals↗
PubMed1987

CT number characteristics of malpositioned TMJ menisci. Diagnosis with CT number highlighting (blinkmode).

The use of computed tomography (CT) number highlighting ("blinkmode") for diagnosing malpositioned temporomandibular joint menisci was investigated. By determining the average CT number, standard deviation, and range for specific periarticular tissues, it is possible to tell how much their attenuation values overlap and, therefore, whether there is a sound basis for distinguishing the disc from adjacent tissues. Fresh and fresh-frozen cadaver specimens, were scanned in axial and direct sagittal planes with 1.5-mm thick overlapping soft-tissue sections. CT number measurements were made for tendon, muscle, fat, and meniscus. Patients also were scanned with overlapping 1.5-mm thick axial soft-tissue sections in order to compare the range of CT numbers in cadavers with that in living subjects. Cadaver joints were cryosectioned at 0.5-mm intervals in the same planes as their CT sections, and the tissue sections were compared with their respective CT highlighted sections. For patients the average CT numbers in Hounsfield units were 88 for tendon, 67 for muscle, -25 for fat, and 100 for meniscus. Fresh unembalmed cadavers showed a higher CT average number for tendon and a lower average CT number for fat. The anatomic sections confirmed the meniscal position seen in the highlighted sections in nine of ten joints (90%) and was equivocal in one. Misshapen and malpositioned discs are seen readily with the blinker function; thinned and normal discs are not. The tendinous insertion of the lateral pterygoid muscle may be confused for meniscus in the medial aspect of the TMJ.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1987

Radiation dose in radiography, CT, and arthrography of the temporomandibular joint.

Thermoluminescent dosimetry studies were performed on a Rando Humanoid head phantom to compare radiation dosages used in temporomandibular joint examinations. Studies included transaxial and direct sagittal high-resolution CT, reduced milliamperage dynamic CT, tomoarthrography, pluridirectional and linear tomography, pantomography, transcranial plain films, and fluoroscopy. Radiation doses were determined for the brain, lens, pituitary gland, condylar marrow, and thyroid gland. Condylar marrow received doses of 64 and 52 mGy, respectively, for the GE 9800 and 8800 high-resolution scans; 21 and 17 mGy, respectively, for the dynamically sequenced scans; and 26 mGy for the GE 9800 direct sagittal sections. Tomoarthrography yielded 31 mGy and fluoroscopy 12 mGy. Other lower doses showed 5 mGy for polytomography, 3 mGy for ipsilateral joint linear tomography, 1.9 mGy for the GE 9800 slow ScoutView, 1.8 mGy for xeroradiography, 0.9 mGy for contralateral joint linear tomography, 0.3-0.4 mGy for transcranial plain films and pantomography, and 0.2 mGy for the GE 8800 ScoutView. The estimated error in this study was calculated to be +/- 15%. On a relative scale, the radiation doses from high-resolution CT and tomoarthrography are high, dynamic CT yields a medium dose, and all other tomographic and plain-film techniques yield low doses.

Arthrography↗