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Biomedical subjects

R Smith

Publications and source records attributed to R Smith.

At least 1,531 records · Page 85Linked to original sources

Clinical and biochemical studies in Engelmann's disease (progressive diaphyseal dysplasia).

The clinical and biochemical features of four adults with Engelmann's disease (Camurati-Engelmann disease; progressive diaphyseal dysplasia) are presented. One young patient, with a particularly severe form of the disease, is discussed in detail. Biochemical abnormalities were found in three of the patients. In two of them, one with localized hyperostosis and one with generalized bone disease, the only changes were an increase in the plasma alkaline phosphatase and urinary total hydroxyproline excretion. The most severely affected patients, who had had progressive and generalized bone disease from age two and a half years, also had persistent hypocalcaemia and hyperphosphataemia, a positive calcium balance, and a very low urine calcium excretion. It is suggested that some patients with Engelmann's disease may have a previously unrecognized metabolic disorder associated with increased retention of calcium and excessive bone formation. The possible role of abnormal phosphate metabolism in this increased formation of bone, and the relationship of Engelmann's disease to other hyperostoses, are discussed.

Adult↗

Mortality in patients treated for pulmonary embolism.

The hospital course of 144 consecutive patients with pulmonary embolism (PE) demonstrated by pulmonary angiography was reviewed to determine the mortality of patients with treated PE. Twelve patients (8%) died of PE, and eight died of causes other than PE; 124 (86%) survived. Pulmonary embolism was the primary cause of death in only four of the 12 patients who died of PE. Pulmonary embolism contributed to the death of eight other patients, each of whom had associated potentially lethal disease, particularly heart disease. The most important factor affecting mortality was shock due to acute right ventricular failure secondary to massive PE (mortality, 32%). Mortality was not related to magnitude of PE per se; the mortality of patients with massive PE without shock (6%) was the same as that for patients with submassive PE (5%. Patients with PE who survive long enough to have the diagnosis established and appropriate prophylactic therapy begun have an excellent prognosis, unless they have associated severe medical disease.

Acute Disease↗

Serum proline imino-peptidase activity in normal adult subjects and in patients with Paget's disease of bone.

The activity of proline imino-peptidase (EC 3.4.1.4) may provide a measure of collagen degradation, and a method for its estimation in human serum is described. The mean value of this enzyme activity in 48 normal adults of 4.7 mU/l (S.D. 0.9) did not change with sex, age or dietary collagen. In 8 patients with liver disease associated with elevated levels of plasma alkaline phosphatase activity the mean value was normal (4.5 mU/l, S.D. 1.5). However, in 25 patients with untreated Paget's disease of bone, values were significantly increased (mean 7.4 mU/l; S.D. 2.8; p less than 0.001) and were positively correlated with plasma alkaline phosphatase activity (r = 0.75; p less than 0.001) and with urine total hydroxyproline excretion (r = 0.68; p less than 0.001). In patients given disodium ethane-1-hydroxy-1,1-diphosphonate for 3--6 months, serum proline imino-peptidase activity decreased to normal values.

Adult↗

Whole-body in-vivo neutron activation analysis in assessing treatment of renal osteodystrophy with 1-alpha-hydroxycholecalciferol.

Four selected adults with different patterns of osteodystrophy receiving regular dialysis were treated with 1-alpha-hydroxycholecalciferol (1-alpha-OHD3) 0-5-2 mug/day for 10 to 12 months. In two patients, one with osteitis fibrosa and the other with osteomalacia, significant biochemical, radiological, and histological improvements occurred, and total body calcium measured by in-vivo neutron activation analysis increased. In two patients, in whom there were no increases of whole-body calcium, neither biochemical improvement nor healing of bone lesions occurred during the study; in one of these patients the effect of 1-alpha-OHD3 on bone resorption may have contributed to loss of body calcium and deterioration of bone disease. 1-alpha-OHD3 may therefore be a valuable adjunct in the treatment of only some patients with renal osteodystrophy. Whole-body in-vivo neutron activation seems to provide a sensitive and non-invasive index of early response to treatment.

Adult↗

Gallstone pancreatitis with normal biliary radiology.

Three patients with relapsing gallstone pancreatitis and normal routine biliary radiology are reported and discussed. It is emphasized that when dealing with recurrent pancreatitis for which no cause is evident, normal conventional biliary radiology (oral cholecystogram and intravenous cholangiogram) should not necessarily be accepted as conclusive. The use of endoscopic cholangiography in such a situation is encouraging.

Adult↗

Effects of neonatal hypothyroidism on cerebral and cerebellar synaptosome development.

The effect of hypothyroidism on cerebral and cerebellar synaptosome development has been studied. Neonatal hypothyroidism was induced following addition of 0.3% propylthiouracil to the diet of nursing mothers. Maturation profiles of total synaptosome fraction and specific activities of lactate dehydrogenase, Na+K ATPase, cytochrome c oxidase, and protein were obtained from days 6 to 32 on synaptosomes isolated from Ficoll-sucrose gradients. The greatest changes were found in the total activities of enzymes isolated from the cerebellum. Hypothyroidism induced a retardation of LDH and cytochrome c oxidase in cerebellar synaptosomes, but no change in corresponding specific activities. Maximum rates of 14C-leucine incorporation into cerebellar synaptosome protein was found at 16-20 days, after which a rapid decline occurred to adult levels at 32 days. In neonatal hypothyroidism, synthesis was significantly reduced at 8 and 14 days, but reached control levels or above at 21--32 days. In the cerebrum, maximum rates of 14C-leucine incorporation into synaptosome protein were identified at 8--12 days in normal with a rapid drop to adult levels at approximately 20 days. In neonatal hypothyroidism, peak activities were identified at 14 days and increased activities over control were noted at 14, 20 and 30 days. These observations demonstrate the sensitivity of the developing cerebellar synaptic apparatus to neonatal hypothyroidism, with a protraction in the peak levels of synaptosome protein synthesis in cerebrum and cerebellum.

Adenosine Triphosphatases↗

Effect of ionizing radiation on liver microcirculation and oxygenation.

Platelet aggregation and adhesiveness, as well as TPO2 responses to hypoxia were measured as microcirculation parameters in beagle dogs subject to Co60 ionizing radiation to a dose of 4600 rads in 5 weeks. Simultaneously, changes in blood chemistry and coagulation were also determined. Marked changes in all studied parameters in the post radiation period lead to the conclusion that radiation liver damage is at least in part mediated through microcirculation disturbances.

Animals↗

Lift traffic patterns in a multi-storey residential block.

This paper describes an exploratory survey throughout the user-day of the free-demand lift traffic patterns in a residential block of flats as a step towards compiling a data set of such traffic patterns in various types of accomodation with a view to producing a lift design guide.

Journal Article↗

Branched-chain amino acids, nitrogen excretion and injury in man.

1. Venous blood concentrations of the branched-chain amino acids, valine, leucine and isoleucine, and urinary nitrogen excretion have been measured in sixteen adult males, from 2 h to 7 days after injury, and in four adults after elective skin grafts. 2. In the injured group the concentrations of these amino acids rose significantly 24 h after injury and had doubled at 4 days and remained high; in contrast the skin-graft patients showed no significant change. 3. In those injured patients with initial hyperketonaemia, defined as more than 0-2 mmo1/1, the increase in concentrations of branched-chain amino acids at the fourth and seventh days after injury was significantly less than in those with normoketonaemia, and was accompanied by lower urinary nitrogen excretion throughout the whole period. 4. It is suggested that the changes in the concentration of branched-chain amino acids after injury indicate decreased uptake by muscle or excessive release due to an imbalance between protein synthesis and protein catabolism in this tissue.

Adolescent↗

Skin collagen in idiopathic adolescent scoliosis and Marfan's syndrome.

1. Skin collagen from fifteen patients with idiopathic adolescent scoliosis, three with congenital scoliosis, and fourteen patients with various degrees of Marfan's syndrome has been examined. 2. The stability of a polymeric collagen fraction, extracted from the skin of these patients, to depolymerization, has been compared with that from thirty-one matched control subjects. 3. The mean polymeric collagen stability was significantly reduced (P less than 0-01) in the group of fifteen patients with idiopathic adolescent scoliosis. The individual reductions in stability were greater in the younger patients and no reduction was found in two patients aged 19 years who had a mature skeleton. 4. The mean stability of polymeric skin collagen from the group of patients with Marfan's syndrome was not significantly abnormal, although there were individual low values. 5. Polymeric collagen of low stability was present in individual patients from each clinical group. Instability of collagen (from whatever cause) at a time of rapid growth may contribute to the high incidence of scoliosis in adolescent girls. In boys, adolescent scoliosis is less common and the maximum growth rate occurs at a time when collagen stability is less reduced.

Adolescent↗

Myositis ossificans progressiva. Clinical features of eight patients and their response to treatment.

The clinical features of eight patients with myositis ossificans progressiva are described and the effects of treatment with the diphosphonate EHDP, together with surgical removal of ectopic bone, are assessed. Early correct diagnosis remains unusual, mainly because the significance of the short great toes is unrecognised, and because myositis may be mistaken for bruising, sarcoma or mumps. The diphosphonate disodium etidronate (EDHP) was given to all patients in an attempt to suppress calcification of new lesions; in five of them ectopic bone was removed during the treatment. EHDP sometimes delayed the mineralisation of newly formed bone matrix after surgical removal but this delay could not be predicted. The variable effect of EHDP may depend particularly on the amount absorbed and on the activity of new bone formation.

Adolescent↗

Unification and technical aspects of total t, active t and b lymphocyte rosette assays.

Conditions for rosette formation of human adult T and B lymphocytes with unsensitized and complement coated SRBC respectively, have been examined in this collaborative study. Modified procedures for identifying, by rosette formation, the total T, active T and B-RFC lymphocytes are described. The procedures reported here yielded results for the percent of peripheral blood lymphocytes forming total T, active T and B-RFC for control individuals that are comparable with those previously reported. The advantage of the procedures described here are that they are 1) easy to perform; 2) highly reproducible; 3) allow for the preparation of a single lymphocyte concentration and common reaction mixture volume to be used in all three rosette assays and 4) allow for the removal of non-lymphocytic cells which would interfere with the determination of B-RFC. The use of these procedures would allow other laboratories to obtain similar values so results for controls and various types of patients could be compared.

Adult↗