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Biomedical subjects

S Miller

Publications and source records attributed to S Miller.

At least 559 records · Page 31Linked to original sources
PubMed1977

Systemic mastocytosis in a patient with polycythemia vera treated with radioactive phosphorus.

Systemic mastocytosis occurred as a fatal event in a patient with long-standing polycythemia vera. The patient had been treated over the course of 21 yr with radioactive phosphorus. Possible relationships between mastocytosis and polycythemia vera, and also between mastocytosis and treatment with ionizing radiation, are discussed. Histopathologic and electron microscopic findings are illustrated. Difficulties in establishing the diagnosis of mast cell disease in this setting are also described.

Biopsy↗
PubMed1975

Coordination of movements of the kindlimbs and forelimbs in different forms of locomotion in normal and decerebrate cats.

The coupling of movements of the hindlimbs and forelimbs has been analysed in intact cats stepping overground and on a treadmill and during swimming, and in decerebrate cats stepping on a treadmill, immersed in water('swimming') and stepping suspended in the air. In the different preparations, and under different types of locomotion, two basic patterns of coupling have been observed. Both concern the hindlimb and forelimb of the same side of the body. The first pattern is found in the pacing gait where flexion of the forelimb precedes extension of the hindlimb, measured at the elbow and knee, respectively. The second pattern is typically found in the trot where flexion of the forelimb follows extension of the hindlimb. In decerebrate cats both patterns of coupling remain after bilateral deafferentation of the hindlimbs. In the alternate form of locomotion these patterns of coupling occurs symmetrically on both sides. In the rotatory and transverse gallop (examples of the in-phase form of locomotion) the coupling is asymmetrical: on one side it is comparable to pacing (forelimb flexion precedes hindlimb extension), and on the other side to trotting (forelimb flexion follows extension). These basic patterns of interlimb coordination simplify considerably the problem of neural control of the limbs in locomotion. Obersations of EMGs during the alternative forms of locomotion show that in the pacing type of coupling the extensor EMGs of forelimb and hindlimb overlap, with the hindlimb leading the forelimb by about 10% of a step cycle, while in the trotting type of coupling the forelimb flexor EMGs overlap the hindlimb extensor EMGs, the forelimb flexors leading the hindlimb extensors by about 10% of a step cycle. During acceleration the transition between the two forms of EMG occurs within one or two step cycles, and at some intermediate velocities the EMG coupling springs back and forth between the two different forms. These results further support the hypotesis of two basic forms of interlimb coupling in which long propriospinal pathways probably play a role.

Animals↗
PubMed1975

Locomotion in the cat: basic programmes of movement.

Observations in cats of flexion and extension movements of the 4 limbs have led to the conclusion that the different forms of alternative locomotion (e.g. walking, trotting, swimming) and in-phase locomotion (galloping, jumping) result from the interaction of 'programmes' for the coordination of (1) the homologous limbs (pair of hindlimbs or pair of forelimbs) and (2) the homolateral limbs (hind- and forelimb of the same side of the body). The movements of the homologous pairs of limbs are coupled out of phase in alternate locomotion and approximately in phase in the phase form of locomotion. The movements of the homolateral pairs of limbs occur approximately out of phase in the trotting type of coupling and approximately in phase in the pacing type of coupling. Transitions between the different forms of coupling occur abruptly over 1 or 2 steps. Therefore, for each type of coupling (homologous or homolateral) there are two distinct forms or 'programmes' of movement. The hypothesis is advanced that (a) all the characteristic patterns of locomotion in the cat result from different combinations of these 'programmes' of homologous and homolateral limb coupling; (b) the 'programmes' are mutually self reinforcing in the gaits in which the coordination of the movements of the 4 limbs is bilaterally symmetrical; (c) the 'programmes' act in competition in certain gaits which are not bilaterally symmetrical giving rise at times to a changing gait pattern, and (d) the temporary dominance of one 'programme' or another can determine the gait of the particular step.

5-Hydroxytryptophan↗
PubMed1975

Movements of the forelimbs of the cat during stepping on a treadmill.

In normal cats stepping on a treadmill an analysis has been made of movements of the scapula, shoulder, elbow, wrist and digits. The scapula is capable of making large and complicated movements over the rib cage. In locomotion they may be resolved into a cyclical, similunar movement of the glenoid cavity in the parasagittal plane of the cat's body. The movements of the scapula are rather constant over a wide range of velocities. They most resemble those of the hip which also shows a delay in the onset of extension and no yield phase. It is suggested that movements of the scapula have a high priority in the execution of locomotion in the forelimbs. The movements at the shoulder tend to parallel those of the elbow. The terms of palmar flexion and dorsiflexion are retained for the movements at the wrist and digits. The rapid phase of palmar flexion corresponds with the flexion phase at the elbow, and the phase of dorsiflexion with the first extension phase at the elbow. Palmar flexion during the second and third extension phases of the more proximal joints would appear to be initiated by contact of the foot with the ground. The sequences of movement at the wrist and digits allow a comparison of the roles of flexor and extensor muscles of the forearm during locomotion and the flexion reflex, which is compatible with the functional and anatomical organization of cervicothoracic segments. With exception of extension at the scapula the movements of the elbow provide an index of the onsets of flexion and extension at the other joints of the forelimb. Modifications are suggested for the Phillippson step cycle of both forelimbs and hindlimbs to include the delayed onset of extension at the scapula and hip and the particular movements of the wrist, digits and toes.

Animals↗
PubMed1975

Polymorphism at the alpha-glycerophosphate dehydrogenase locus in Drosophila melanogaster. I. Properties of adult allozymes.

A biochemical comparison was made between alpha-glycerophosphate dehydrogenase allozymes from Drosophila melanogaster. Enzymes extracted from the three major genotypes were indistinguishable in terms of their pH optima and thermal stabilities. Distinctive differences were observed for three parameters; temperature dependence of specific activity, temperature dependence of K-m, and reaction rate constancy over a physiological temperature range. These results are discussed in terms of a model of balancing selection and the existence of spatial and temporal allele frequency clines in natural populations.

Alleles↗
PubMed1975

Assessment of Peroheme-40 for the presence of occult blood in the faeces.

Peroheme 40, a chemical test for occult blood in faeces, has been assessed by comparing it with results obtained using 51Cr labelled red cells. The study was carried out in two parts. Initially testing was carried out on 75 stool samples from 20 patients on a restricted diet, and in the second part, testing was performed on 40 samples from 10 patients on a normal ward diet. All patients were suspected of losing blood from the gastrointestinal tract. On the restricted diet there were 29 per cent false positive and 13 per cent false negative results, while on the normal diet, there were 86 per cent false positive and 8 per cent false negative results. Peroheme-40 has therefore been shown, on a restricted diet, to compare favourably with previously available chemical tests.

2,6-Dichloroindophenol↗
PubMed1975

Demonstration of a diurnal variation in serum parathyroid hormone in primary and secondary hyperparathyroidism.

It had been reported previously that there is a diurnal variation in serum parathyroid hormone (PTH) in normal subjects but not in patients with primary hyperparathyroidism. Studies were performed to determine whether there is a diurnal variation in serum PTH in primary or secondary hyperparathyroidism and whether the nocturnal increase in serum PTH, if present, could be prevented by induced hypercalcemia. Serum PTH and calcium were measured in five normal subjects, two patients with pseudohypoparathyroidism, and fourteen patients with primary hyperparathyroidism, twelve of whom were subsequently found to have parathyroid adenomas. In the normals, there was a mean decline in serum PTH of 0.07 ng/ml before noon and a mean increase of 0.04 ng/ml after 8 PM. In primary hyperparathyroidism there was a mean decline in serum PTH before noon of 0.11 ng/ml and a mean increase of 0.11 ng/ml after 8 PM. In both groups, the lowest mean serum calcium values were noted between midnight and 6:00 AM. Patients with pseudohypoparathyroidism showed a nocturnal increase in serum PTH. In each of two normal subjects, two patients with primary hyperparathyroidism, and two patients with pseudohypoparathyroidism, calcium, 4 mg/kg body weight per hour for 4 hours (8:00 PM to 12 midnight), produced hypercalcemia and prevented the nocturnal increase in serum PTH. We have concluded that a diurnal variation in serum PTH often occurs in both normal subjects and in patients with primary or secondary hyperparathyroidism and that nocturnal increases in serum PTH can be prevented by induced hypercalcemia.

Adult↗