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Biomedical subjects

C Anderson

Publications and source records attributed to C Anderson.

At least 505 records · Page 28Linked to original sources
PubMed1986

Association of amyoplasia with gastroschisis, bowel atresia, and defects of the muscular layer of the trunk.

We reviewed 225 cases of amyoplasia, and the association of amyoplasia with gastroschisis and with monozygotic twinning was confirmed. In addition, an apparently increased association of bowel atresia and defects in the muscular layer of the trunk wall with amyoplasia was observed. The association of amyoplasia, monozygotic twinning, and these trunk wall defects strongly suggests that the pathogenesis of amyoplasia is linked to some type of vascular compromise.

Abdominal Muscles↗
PubMed1986

The effects of 17 beta-estradiol and progestagen on trabecular bone remodeling in oophorectomized dogs.

We present the results of the static and dynamic histomorphometric analyses of parameter measurements of trabecular bone remodeling activity in nonoophorectomized, untreated oophorectomized, 17 beta-estradiol-supplemented oophorectomized, as well as progestagen-supplemented oophorectomized beagle dams. If the spayed beagle dam can be considered a model in which one may equivalate bone changes occurring in the ovarian hormone-deficient human female, we reach the following conclusions: The presence or absence of quasi-physiological levels of single ovarian hormones do affect the status of trabecular bone. The evidence indicates that the presence or absence of individual ovarian hormones do not have a simple effect on trabecular bone remodeling. Apart from affecting the numbers of new bone remodeling units (BMUs) that are initiated in unit time, their effect is seen to be extended to the working efficiency of existing osteoclasts and osteoblasts. The effect is also manifest on the total amount of work performed by the collections of osteoclasts and osteoblasts that provide the respective resorptive and formation phases of the BMU. Finally, we are led to believe that there may be a close interdependence both in physiological activity and therapeutic response between the four active bone envelopes. Such protein effects have hitherto not received their due consideration from researchers in this field.

Animals↗
PubMed1986

Short-term chronic fluoride administration and trabecular bone remodeling in beagles: a pilot study.

We carried out a pilot project to examine the alterations in trabecular bone remodeling activity of spayed Beagle dams exposed to 0.7 mg/kg body wt/day of sodium fluoride (NaF) for a 6 month period. The results indicated that short-term NaF administration does activate trabecular bone remodeling activity by stimulating the formation of new Basic Multicellular Units (BMUs) of bone remodeling activity. However, interference with bone cell differentiation, with the functional efficiency and/or life-span of individual osteoclasts and osteoblasts followed. Cellular toxic effects appear early with NaF administration, and as such, suggest that the increases in bone mass seen early in the course of NaF treatment may be negated by prolonged administration of this substance. However, preservation of bone mass will probably result with long-term therapy, due to decreases in numbers of bone cells, in their functional efficiencies, and in their individual life-spans.

Animals↗
PubMed1986

Surface activity on the periosteal and corticoendosteal envelopes following continuous progestogen supplementation in spayed beagles.

Resorptive and formative characteristics on the periosteal and corticoendosteal bone envelopes were assessed on the ribs of intact, spayed and medroxyprogesterone acetate (MPA)-supplemented Beagle dams. Histomorphometric analyses of the alterations on surface activities of these two envelopes were carried out using tetracycline labeling. It was found that continuous administration of progestogen decreased the extent of resorptive surfaces on the corticoendosteal surfaces of progestogen-treated animals vs. spayed animals. On the periosteal surfaces the progestogen-treated dogs showed a marked increase in formation when compared to spayed and intact dogs. As a result of continuous progestogen treatment, mineralization lag time was shortened on the corticoendosteum and periosteum of progestogen-treated animals when compared to the same surfaces on the bones of intact and spayed animals.

Animals↗
PubMed1986

Soy fiber improves lipid and carbohydrate metabolism in primary hyperlipidemic subjects.

This study was designed to evaluate the effects of soy fiber, a natural source of dietary fiber that consists of both cellulosic and noncellulosic dietary fiber, on human plasma lipoprotein lipids and glucose tolerance in patients with primary hyperlipidemia. Supplementing 25 g of soy fiber per day provided a significant additional reduction of plasma total-cholesterol by 13 mg/dl (P less than 0.04) and LDL cholesterol by 12 mg/dl (P less than 0.05) beyond that previously achieved by treatment with an NIH Type II-A low-fat, low-cholesterol diet for 12 weeks in Type II-A hypercholesterolemic patients. There were no effects on HDL cholesterol or apoprotein A-I and A-II levels. The hypocholesterolemic effect was greater than in the hyperlipidemic patients with impaired glucose tolerance. Soy fiber supplementation also significantly reduced insulin responses to oral glucose challenge by 20% in Type II-A hypercholesterolemic and by 16.5% in Type IV hypertriglyceridemic patients. Results from this study suggest that supplementing the diet with soy fiber may be beneficial in dietary management of hyperlipidemia in patients with hypercholesterolemia and particularly in hyperlipidemic patients with hyperinsulinemia and impaired glucose tolerance.

Apoproteins↗
PubMed1986

Hypophosphatemic osteomalacia complicating von Recklinghausen's neurofibromatosis: increase in spinal density on treatment.

A 62-year-old white male with neurofibromatosis presented with multiple fractures and bone pain. He was found to have hypophosphatemic osteomalacia secondary to a renal tubular phosphate leak and was treated with phosphate, 1,25-dihydroxycholecalciferol and calcium. With treatment, his dual photon vertebral bone density increased markedly over 12 months. Repeat iliac crest bone biopsies showed that improvement in bone histology was predominantly cortical. This suggests that dual photon absorptiometry of the spine may be markedly influenced by changes in cortical bone status.

Biopsy↗
PubMed1986

The temporalis myo-osseous flap: an experimental study.

The present paper investigates the anatomy and vascularization of the temporalis myo-osseous flap. This is a calvarial bone flap that employs temporalis muscle and its distal pericranial extension as a pedicle. In six human cadavers the flap was raised as an island on the anterior deep temporal artery after transecting the zygomatic arch and coronoid process. Maximal mobilization was thus obtained, allowing rotation of the flap into the mouth for intraoral reconstruction. The arc of rotation and potential surgical applications were noted. A comparative study of the temporalis myo-osseous flap and free calvarial bone graft was then conducted in a rabbit model. Vascularization of the calvarial bone flap was confirmed by technetium scintigraphy performed on the first postoperative day. The uptake of fluorochrome labels immediately after transfer verified the adequacy of the periosteal circulation in maintaining viability and new osteoid formation throughout the full thickness of calvarial bone. The transplantation of free calvarial bone grafts was followed by necrosis of most cellular elements. This was demonstrated by an absence of fluorochrome uptake up to 19 days postoperatively and a predominance of empty lacunae and nonviable marrow.

Animals↗
PubMed1986

Animal model for assessment of skin irritancy.

Irritant skin reactions from repeated open applications of low concentrations of sodium lauryl sulphate (SLS) have been studied macroscopically and microscopically in guinea pigs. After 3 applications daily for 3 days, 2% SLS aqueous solutions gave a naked eye assessment, increase in epidermal thickness and total dermal inflammatory cell response, which was greater than for a 1% SLS solution. The dermal inflammatory cell response was mainly mononuclear (lymphocytic) in nature. With the SLS reactions as control, various organic solvents were studied and ranked against the SLS reactions and internally. Trichlorethylene was the most irritant solvent, ranking as high as 2% SLS. Other chlorinated hydrocarbons and aromatic hydrocarbons tested caused irritant reactions. The alcohols and acetone gave no reaction. White spirit was as irritant as trichlorethylene. Thinners were less irritant, around the level of the 1% SLS control reaction. The 4-day experimental design is a convenient and suitable animal model for screening irritant potential, and provides information relevant to the pathogenesis of irritant contact reactions.

Animals↗
PubMed1986

Micropsia and metamorphopsia in the re-attached macula following retinal detachment.

Macular dysfunction was studied in 7 patients recovering after surgery for a retinal detachment involving the macula. The degree of disturbed size perception (dysmetropsia) and metamorphopsia was measured in parallel with letter and grating acuity in patients during the recovery process for time periods up to 47 months following successful re-attachment. The demonstration of dysmetropsia, quantitatively assessed by a matching technique, in several patients indicate that the spatial density of the macular photoreceptors changes following detachment. In 3 patients out of 7 a longstanding micropsia was present. The degree of micropsia was not related to the degree of metamorphopsia. Subclinical/clinical macular oedema is considered to be the most probable cause for the increased separation of the macular photoreceptors. The study indicates that quantitative measurement of dysmetropsia gives valid information about receptor displacement and of unilateral subclinical macular oedema. The relations between letter acuity, grating acuity and micropsia gives certain information about the role of changed receptor separation as a cause of impaired central vision, and we found that incomplete recovery of acuity partly can be due to long-standing separation of foveal receptors.

Adolescent↗
PubMed1986

The effect of some immunomodulating agents on the sensitization phase of experimental contact allergic reactions.

In an experimental model which allows comparison of the macroscopic changes with the differentiated dermal inflammatory cell infiltrate of the allergic contact reaction to oxazolone in guinea pigs, the effects of single doses of the cytostatic agents cyclophosphamide, methotrexate and azathioprine and the anti-lymphocyte agent cyclosporin A administered prior to sensitization were studied. All the agents tested increased the degree of erythema and edema of reactions compared to controls. The dermal inflammatory mononuclear cell response showed little significant increase and would not seem to explain the enhancement of reactions. The number of basophils in reactions was not significantly different from controls, and there is no evidence for early arrival, degranulation and destruction of basophils prior to our first routine assessment at 24 h. The number of mast cells in the reactions was also unchanged. A role for the latter two cells involving degranulation without changes in the number of cells could provide a possible explanation for the augmentation of the vascular response. A mechanism for the effect of cyclophosphamide other than T-suppressor lymphocyte susceptibility based on selective cytostatic effects on precursor cells may need to be considered.

Animals↗
PubMed1986

Alterations in corticotropin-releasing factor-like immunoreactivity in discrete rat brain regions after acute and chronic stress.

Corticotropin releasing factor (CRF) may regulate endocrine, autonomic, and behavioral responses to stress. Evidence indicates that CRF-like immunoreactivity (CRF-LI) is widely distributed throughout the CNS. In this study, the distribution of CRF-LI was determined in 36 rat brain regions by combined radioimmunoassay-micropunch dissection techniques and the effect of stress on CRF-LI was investigated, using a chronic stress model that induces endocrine changes in rats similar to those seen in depressed humans. A control group of rats was handled daily. An acute stress group was subjected to 3 hr of immobilization at 4 degrees C, while a chronic stress group was exposed to unpredictable stressors. Thirty-six brain regions were microdissected by the technique of Palkovits and assayed for CRF-LI, using a specific antiserum to ovine CRF. CRF-LI was detected in most regions. In controls, the highest concentrations were found in the arcuate nucleus/median eminence, the hypothalamic paraventricular (PVN) nucleus, and the periventricular nucleus. The next highest levels were found in the raphe nuclei and dorsal vagal complex. CRF-LI was well represented in the locus coeruleus (LC); in the central, cortical, and medial amygdaloid nuclei; and in the bed nucleus of the stria terminalis. Low concentrations occurred in the hippocampus and cerebrocortical regions. Appreciable concentrations were detected in midbrain and brain stem regions. Acute stress reduced CRF-LI in the arcuate nucleus/median eminence (ME) (by 52%) and in the median preoptic (MPO) nucleus (by 32%) and doubled its concentration in the locus coeruleus.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute Disease↗
PubMed1986

Embryonic heart rates before the seventh week of pregnancy.

Previous studies of normal human embryonic heart rates showed an increase in the rates between the 7th and 9th gestational weeks; the rates gradually declined thereafter until the 15th week. The present study added new information about embryonic heart rates before the seventh week. The heart rates are slower than those reported to occur after the seventh week. These observations are connected with morphologic and physiologic changes during this period of embryonic life.

Female↗
PubMed1986

Bone remodeling in the lumbar vertebrae of young adult beagles.

Thirty-two static and dynamic histomorphometric determinants of tetracycline-labeled trabecular bone were determined for the L1 and L3 vertebrae of 5 intact and 6 oophorectomized Beagle bitches. Because significant differences in trabecular bone remodeling between the 2 vertebrae were not found, we concluded that the mean of the combined L1 and L3 data, or the mean of data generated from individual vertebrae, may be representative of trabecular bone remodeling of the lumbar vertebrae of Beagles.

Animals↗
PubMed1985

Syndrome of camptodactyly, ankyloses, facial anomalies, and pulmonary hypoplasia (Pena-Shokeir syndrome): obstetric and ultrasound aspects.

Two siblings with Pena-Shokeir syndrome are described. This syndrome consists of polyhydramnios, intrauterine growth retardation, short umbilical cord, perinatal death, facial abnormalities, limb abnormalities including arthrogryposis, and lethal pulmonary hypoplasia. The mode of inheritance is most likely autosomal recessive. Prenatal diagnosis was made in the second pregnancy with ultrasound performed at 26 weeks' gestation. The roles of fetal akinesia and fetal apnea in the production of the various manifestations of the syndrome are detailed, and the possibility of early prenatal diagnosis is considered.

Abnormalities, Multiple↗