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Biomedical subjects

R S Riggins

Publications and source records attributed to R S Riggins.

At least 37 records · Page 2Linked to original sources
PubMed1977

Scoliosis in chickens.

Scoliosis developed in 55 per cent of sexually mature birds (68 per cent of male and 46 per cent of female birds) in a highly inbred line of chickens originally produced from white Leghorns. The curve could first be detected at five to six weeks of age and progressed until spontaneous fusion of the thoracic vertebrae occurred. Studies of these chickens indicated that abnormalities of growth and development of the spine are not the primary cause of the scoliosis. Preliminary studies of the paravertebral musculature also indicated that simple muscle imbalance is not responsible for the curve. Initial studies of collagen extracted from the scoliotic line of chickens showed it to be more soluble than similar collagen extracted from white Leghorn controls.

Animals↗
PubMed1976

Effects of fluoride and ethane-1-hydroxy-1,1-diphosphonate on bone metabolism in the growing chick.

White Leghorn cockerols were fed a semipurified diet (containing fluoride at 0 to 800 ppm) from the day of hatching. The birds were also injected daily with solutions containing ethane-1-hydroxy-1,1-diphosphonate (EHDP) at concentrations ranging from 5 to 20 mg as phosphorus/kg of body weight or isotonic saline. Changes in bone mineral composition and plasma Ca, Mg and F were determined as well as alterations in bone pyrophosphatase and the amounts of bone cyclic-3',5'-adenosine monophosphate (cAMP). Since dietary fluoride in high amounts is known to stimulate new bone formation, the purpose of the study was to assess whether a potent inhibitor of mineralization, such as EHDP, might alter the response to high dietary fluoride. Although bone fluoride and magnesium were increased in relationship to dietary fluoride, the administration of EHDP had little effect on these changes at low to moderate levels of fluoride. The levels of soluble bone pyrophosphatase were not greatly influenced by changes in dietary fluoride. Administration of EHDP at 20 mg P/kg, however, typically decreased the levels of bone pyrophosphatase. Bone cAMP did not appear to be influenced by either dietary fluoride or EHDP. Using tissue culture techniques, the effects of fluoride on calcium uptake and release from embryonic chick bone were also studied. The presence of 1 mM fluoride in the medium appeared to stimulate calcium uptake and reduced calcium release from chick bone. In general, the results were in keeping with previous suggestions that the major effect of fluoride on bone is the formation of fluoroapatite and subsequent effects this may have on other metabolic alterations.

Alkaline Phosphatase↗
PubMed1976

Scheuermann's kyphoscoliosis associated with Charcot-Marie-Tooth syndrome.

Much confusion and disagreement exists regarding the classification and characteristics of inherited disorders manifesting neurogenic muscular atrophy. Many authors consider Charcot-Marie-Tooth syndrome (CMTS) and Roussy Levy syndrome (RLS) forme fruste or variants of Friedreich's ataxia (FA). Familial kyphoscoliosis has often been described in FA and RLS but not with CMTS. The purpose of this paper is to present detailed clinical and laboratory findings in a family with three cases of Scheuermann's kyphoscoliosis and CMTS in three generations. In all cases Scheuermann's kyphoscoliosis was associated with pes cavus, markedly diminished vibratory and position sensation in the lower extremities, absent deep tendon reflexes and muscular atrophy, predominantly of the distal muscles. Fine rhythmic tremor of outstretched hands and positive Romberg sign were present in one case only. Serum creating phosphokinase was elevated in two cases. Motor nerve conduction studies revealed impaired function in the median, ulnar, tibial and peroneal nerves. Sensory nerve conduction wal also impaired in median and ulnar nerves. There was evidence of left ventricular hypertrophy in one case only. The nosology and relationship between CMTS, RLS and FA are discussed.

Adolescent↗
PubMed1975

Effects of nutritional copper deficiency on the biomechanical properties of bone and arterial elastin metabolism in the chick.

Increased bone fragility was observed in chickens fed diets containing less than 1 ppm copper. Using a device that was designed to measure torsion during fracture, it could be demonstrated that bone from copper-deficient chicks fractured with less deformation and torque than bone from control chicks. The collagen of bone from copper-deficient chicks appeared to contain fewer cross-links than normal bone. The introduction of artificial cross-links into collagen from copper-deficient chick bone by formaldehyde and NaBH4 treatments improved bone strength and strain (deformation) so that it was comparable with normal bone. Copper deficiency blocks the formation of cross-links in collagens and elastin from various tissues. It is felt that the bone fragility related to nutritional copper deficiency is the result of decreased bone collagen cross linking. Arterial elastin metabolism was also investigated. By radioactively labeling arterial soluble elastin (tropoelastin) in vivo by an intraperitoneal injection of [G-3H]valine, it could be demonstrated that copper deficiency appeared to reduce its rate of metabolic turnover. Soluble elastin or tropoelastin is assumed to be the precursor of mature or insoluble elastin. The observations presented here are consistent with the view that by retarding the steps associated with elastin cross-link formation, the incorporation of soluble elastin into mature elastin may be retarded as well.

Animal Nutritional Physiological Phenomena↗
PubMed1975

Some epidemiologic features of motorcycle collision injuries. I. Introduction, methods and factors associated with incidence.

Using official police reports and hospital admission and emergency room medical records, 1273 persons with confirmed medically treated motorcycle injury were identified in Sacramento County, California, during 1970. Less than 39% of all injured motorcyclists were identified in this study using only official police reports. The annual incidence rate was highest for 18-year-old male drivers. In addition to age of driver, risk of injury was associated with drivers of short stature (less than 173 cm) operating an intermediate or larger size motorcycle. Risk of injury was higher for drivers with training than for those without training or those who operated their motorcycles frequently regardless of type of use. Risk of injury was not related to make of motorcycle but was related to engine size. Two-thirds of the injury-producing collisions involved a motorcycle and a second motor vehicle. Motorcycle collisions occurred most fre quently during the afternoon and early evening hours and during the summer months, but peaks in incidence of collisions occurred during weeks which included a holiday.

Accidents, Traffic↗
PubMed1975

Some epidemiologic features of motorcycle collision injuries. II. Factors associated with severity of injuries.

Male drivers sustained relatively more serious motorcycle collision injuries than did male passengers, female drivers, or female passengers. For male drivers, severity of injury was related to age. The relative frequency of serious head injury was highest for drivers not wearing helmets who were involved in collisions at low or high speeds. Severity of injury was related to speed at the time of collision but not in all types of collisions. Factors associated with the incidence of collisions were not identical to those related to the severity of the injury sustained.

Accidents, Traffic↗
PubMed1975

Fluoride-18 scintigraphy in avascular necrotic disorders of bone.

Fluoride-18 scintigraphy is a simple, safe method for evaluating perfusion to bone, and obviates objections to earlier techniques. The scintillation camera with positron detection represents a unique instrumentation system because of its tomographic effect, relative insensitivity to vascular radioactivity in the surrounding skeleton, and excellent spatial resolution despite low counting efficiency. In 75 patients with avascular disorders about the hip, knee, elbow, foot and hand, the impressions obtained from fluoride-18 scintigraphy were correlated with clinical findings and roentgenograms and when possible confirmed by tetracycline labeling and histological examination. Fluoride-18 scintigraphy was useful: in determining the vascularity of the femoral head following femoral neck fractures; in determining results of treatment; and in diagnosing early the various avascular necrotic disorders of the bone.

Adolescent↗
PubMed1975

Injury patterns in motorcycle collisions.

This report describes the incidence, nature, and severity of trauma for injuried and medically treated motorcyclists in Sacramento County, California in 1970. Using official police reports, hospital admission, and emergency-room medical records, 1,273 persons with a confirmed medically treated motorcycle injury were identified. Since less than 39% of all injured motorcyclists were identified in this study by use of official police reports only, statistics which rely solely on these reports greatly underestimate the frequency of motorcycle collision injuries in the community. The annual injury incidence was 2.0 per 1,000 population, with peak incidence injury rate for male drivers 18 years of age. Slightly more than 4% of all registered motorcycles were involved in an injury-producing collision in a single year. Almost 45% of injured motorcyclists suffered a serious injury, with injuries to the musculoskeletal system in the form of fractures being the most common. The average length of hospital stay was 12 days, and three-fourths of those injured indicated one or more days of disability. Physicians should be alert to the fact that persons injured in motorcycle collisions commonly sustain multiple fractures and other serious injuries.

Abdominal Injuries↗
PubMed1975

Healing of electrosurgical and scalpel wounds in rabbits.

Skin wounds in rabbits were tested after healing periods of up to three weeks to determine if scalpel wounds differed from those made electrosurgically. Tensile tests showed that the electrosurgical wounds were initially stronger, but at four days there was no difference. Thereafter the scalpel wounds were stronger and their healing progressed much faster. Histological preparations showed more extensive inflammation and necrosis in the electrosurgical wounds.

Animals↗