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Biomedical subjects

D Gordon

Publications and source records attributed to D Gordon.

At least 379 records · Page 21Linked to original sources

Tumoral calcinosis associated with sarcoidosis and positive bone and gallium imaging.

A 63-year-old female with biopsy proven tumoral calcinosis presented with progressive and recurrent swelling and tenderness of the right hip, thigh, elbow, and wrist. Both gallium and bone imaging demonstrated intense, congruent uptake in these areas. This is the third case of tumoral calcinosis with sarcoidosis documented in the literature. However, these are the first published bone and gallium scans in a patient with a history of sarcoidosis and tumoral calcinosis.

Calcinosis↗

The effect of tamoxifen therapy on thyroid function tests.

Serum tri-iodothyronine (T3), thyroxine (T4) and thyroid-stimulating hormone (TSH) concentrations were measured in 50 postmenopausal patients with breast cancer receiving tamoxifen therapy. Ten patients (20%) showed an elevation of serum total T4 concentrations and two of these patients showed additional elevation of serum total T3 levels. One patient had a persistently raised free T4 concentration and was considered to be thyrotoxic. Serum thyroxine-binding globulin (TBG) was estimated in six patients with elevated total T4 concentrations and was found to be raised in each case. Total serum T4 concentrations rose in seven of ten additional patients after starting tamoxifen therapy. However this change did not reach statistical significance. This trend in serum T4 concentrations was not shown in ten normal volunteers taking tamoxifen for 1 week.

Breast Neoplasms↗

Coordinate and independent effects of heroin, cocaine, and alcohol abuse on T-cell E-rosette formation and antigenic marker expression.

Simultaneous and independent use of cocaine and alcohol by heroin addicts was shown to variably modulate the ability of their T cells to form E-rosettes with sheep erythrocytes (E). As reported previously, the percentages of E-rosette-forming T cells of both active and total types were depressed in association with heroin addiction. We show here that the kinetic curve of the rate of E-rosette formation is also depressed by heroin use and that the use of cocaine but not alcohol by heroin addicts reverses depression of E-rosette formation by heroin. The percentages of E-rosette-forming T cells from the bloods of heroin addicts who used both alcohol and cocaine, as well as the kinetic rate curves of E-rosette formation, were intermediate between the essentially normal levels found for heroin addicts who used cocaine and the severely depressed levels evident for users of heroin alone or heroin plus alcohol. Modulation of the levels of E-rosette formation by alcohol used in conjunction with cocaine and/or heroin was variably dose dependent. Polydrug effects evident by analyses of E-rosette formation were not seen when the percentages of lymphocytes reactive with LYT-3 (anti-E-receptor, 9.6 epitope) and OKT-3 (anti-total T cell) monoclonal antibodies were assessed cytofluorometrically, although the data suggested that subnormal percentages of LYT-3+ T cells were present when heroin addicts also used cocaine. These findings are relevant to basic understanding of T-cell physiology from a neuroimmunological perspective and also suggest ways that addictive drugs may modulate the immunocompetence of drug addicts.

Adult↗

Relevance of spontaneous activity to urinary bladder function: an in vitro and in vivo study.

The presence and functional significance (if any) of spontaneous activity in the normal urinary bladder during filling is a controversial subject. One model used by many investigators to study spontaneous activity has been isolated urinary bladder smooth muscle strips. Although spontaneous activity is a property commonly observed in isolated urinary bladder strip preparations, the in vitro whole bladder preparation (rabbit) is devoid of spontaneous activity. Additionally, under normal conditions the in vivo rabbit bladder does not display spontaneous activity during the filling phases of micturition. The present study compares the spontaneous activity of isolated smooth muscle strips, the whole bladder preparation, and the catheterized in vivo bladder (rabbit). The results are as follows: The spontaneous activity (frequency and amplitude) of isolated strips is extremely variable among strips of the same bladder. Spontaneous activity is not affected by the following specific inhibitory compounds: tetrodotoxin, atropine, phentolamine, propranolol and hexamethonium. This indicates that spontaneous activity observed in isolated strips is myogenic in nature and not dependent on the activation of specific autonomic receptors. The in vitro whole bladder preparation shows no spontaneous activity at any volume or pressure unless longitudinal tension is applied. The spontaneous activity of the whole bladder subjected to longitudinal tension is not affected by the same compounds mentioned above. Spontaneous activity of the in vivo bladder is absent at low intravesical volumes and pressures. Spontaneous activity develops upon reaching a critical pressure. However, this activity is completely inhibited by intravenous ganglionic blockade (hexamethonium). In the presence of hexamethonium, the in vivo bladder is devoid of spontaneous activity at any volume or pressure, thus the in vivo "spontaneous activity" is mediated through neuronal reflexes. It is concluded that under normal circumstances the rabbit bladder is devoid of myogenic spontaneous activity and that the spontaneous activity observed in isolated strips is directly related to longitudinal stretch. Since under normal conditions the bladder is not subjected to longitudinal stretch, the spontaneous activity observed in the isolated strip studies has little physiological significance under normal conditions, but could help explain the pathophysiology of certain dysfunctions during the filling stage of micturition.

Animals↗

Congenital aneurysm of the left sinus of Valsalva with an aortopulmonary tunnel.

Aneurysm of the left sinus of Valsalva is rare, and there is only one previous report of rupture into the pulmonary artery. This report describes a patient with valvular pulmonary atresia and ventricular septal defect in whom a portion of his pulmonary blood flow was supplied by an aortopulmonary tunnel arising from a left sinus of Valsalva aneurysm. The surgical implications of precise definition of the type of aortopulmonary communication are discussed.

Aorta↗

Expression of smooth muscle-specific alpha-isoactin in cultured vascular smooth muscle cells: relationship between growth and cytodifferentiation.

The relationship between growth and cytodifferentiation was studied in cultured rat aortic smooth muscle cells (SMCs) using expression of the smooth muscle (SM)-specific isoactins (Vanderkerckhove, J., and K. Weber, 1979, Differentiation, 14:123-133) as a marker for differentiation in these cells. Isoactin expression was evaluated by: (a) measurements of fractional isoactin content and synthesis ([35S]methionine incorporation) by densitometric evaluation of two-dimensional isoelectric focusing sodium dodecyl sulfate gels, and (b) immunocytological examination using SM-specific isoactin antibodies. Results showed the following: (a) Loss of alpha-SM isoactin was not a prerequisite for initiation of cellular proliferation in primary cultures of rat aortic SMCs. (b) alpha-SM isoactin synthesis and content were low in subconfluent log phase growth cells but increased nearly threefold in density-arrested postconfluent cells. Conversely, beta-nonmuscle actin synthesis and content were higher in rapidly dividing subconfluent cultures than in quiescent postconfluent cultures. These changes were observed in primary and subpassaged cultures. (c) alpha-SM actin synthesis was increased by growth arrest of sparse cultures in serum-free medium (SFM; Libby, P., and K. V. O'Brien, 1983, J. Cell. Physiol., 115:217-223) but reached levels equivalent to density-arrested cells only after extended periods in SFM (i.e., greater than 5 d). (d) SFM did not further augment alpha-SM actin synthesis in postconfluent SMC cultures. (e) Serum stimulation of cells that had been growth-arrested in SFM resulted in a dramatic decrease in alpha-SM actin synthesis that preceded the onset of cellular proliferation. These findings demonstrate that cultured vascular SMCs undergo differential expression of isoactins in relation to their growth state and indicate that growth arrest promotes cytodifferentiation in these cells.

Actins↗

Roy-Camille plates in unstable spinal conditions. A preliminary report.

From 1979 to 1982, 21 consecutive patients with posttraumatic or pathologic fractures of the spine were treated at the University of Sherbrooke by Roy-Camille plates to provide stabilization. Ten burst fractures and 11 fracture-dislocations were treated in this manner. Nine patients had complete paraplegia, 6 had various neurologic deficits, and 6 had no neurologic problems before operation. Using the technique described by Roy-Camille, the authors stabilized the spine with two plates in 18 patients and one plate plus fusion in 3. No major complications occurred with surgery nor after a follow-up of 1-3 1/2 years. Sixteen patients had no loss of correction, and 5 lost 10 degrees-12 degrees. This technique was safe and effective and thought to be a valid alternative to conventional forms of spinal fixation, particularly in paraplegic patients, in those with spinal metastasses, and in those necessitating extensive laminectomies impairing spinal stability.

Adolescent↗

Induction of polyploidy in cultures of neonatal rat aortic smooth muscle cells.

Arterial smooth muscle cells become tetraploid with age and hypertension. To further study this phenomenon, neonatal rat aortic smooth muscle cells were placed in cell culture and studied over time. Numerous cells with tetraploid and even octaploid DNA content appeared beginning in primary cultures. These increases in DNA content per cell were determined by quantitative fluorescence microscopy and flow cytometry, and true polyploidy was confirmed by chromosome counts. In contrast, cells from adult rat aortas failed to produce significant polyploid cells over time in culture. In vitro culture of neonatal aortic cells may therefore be a model system for studying the initiation of polyploidy in arterial smooth muscle.

Actins↗

Analysis of heart rate and respiratory patterns in sudden infant death syndrome victims and control infants.

Retrospective analyses of patterns of breathing and heart rate variability obtained by visual inspection and spectral analysis of ECG and respiratory activity have provided markers associated with subsequent death in a referred population of infants at high risk for sudden infant death syndrome (SIDS). Such markers include breathing patterns characterized by excessive apneic pauses and periodic breathing, heart rate spectra characterized by increased low frequency oscillations, and respiratory activity spectra characterized by a widened "bandwidth" during regular breathing. To test whether such measurements could distinguish SIDS cases and randomly selected controls from a population study the data from 10 cases and 100 age-matched control subjects were analyzed blind. The code was disclosed after completion of the analysis. We found that none of the markers served to distinguish the SIDS cases from the controls in the population at large. This observation may indicate important physiological differences between infants destined to die in the referred high risk population and infants who die of SIDS at large. The possible reasons for our inability to identify the group of SIDS in the general population, as compared to the group of deaths in the referred high risk group are: (1) different disease processes in the two groups, (2) difference responses to the same disease process in the two groups, (3) a response reflecting the psychosocial setting of the referred high risk population, (4) methodological differences between this and previous studies. We conclude that these markers are not of value in screening the population at large.

Heart Rate↗

Believe in them.

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Employment↗

Androgenic status and sexual function in males with rheumatoid arthritis and ankylosing spondylitis.

The pituitary-testicular axis was investigated in 31 males with rheumatoid arthritis (age range 19-60 years, median 55 years) and 33 males with ankylosing spondylitis (age range 22-55 years, median 37 years) and compared with a control group of 95 normal male volunteers. Using analysis of covariance, patients with rheumatoid arthritis showed significantly lower serum testosterone (p less than 0.05) and derived free testosterone (p less than 0.01) concentrations and significantly higher serum LH and FSH concentrations (p less than 0.05) compared with controls. All patients had normal serum prolactin and cortisol concentrations. Serum testosterone correlated with ESR, haemoglobin concentrations and rheumatoid factor titres (r = -0.448, p less than 0.02; r = 0.440, p less than 0.02; r = -0.360, p less than 0.05 respectively) in the rheumatoid patients. Although there was a significant negative correlation between ESR and haemoglobin concentrations (p less than 0.005) in the patients with ankylosing spondylitis, neither variable correlated with serum testosterone concentrations. There was no association between testicular dysfunction and the presence of extra-articular features of rheumatoid arthritis. Ten patients (33 per cent) with rheumatoid arthritis and four (13 per cent) with ankylosing spondylitis admitted to periods of impotence while 15 (50 per cent) of the former and 12 (39 per cent) of the latter had periods of decreased libido. There was no evidence for increased rates of infertility in either group.

Adult↗

Treatment of presumed prolactinoma by transsphenoidal operation: early and late results.

Seventy seven patients who were presumed to have a prolactinoma on the basis of biochemical findings underwent transsphenoidal operation between October 1977 and September 1983. Sixty one patients were found to have a microadenoma, and hyperprolactinaemia was cured in 46 of these, amenorrhoea in 39 (80% of those with the symptom), galactorrhoea in 32 (80%), and infertility in 31 (82%). Four of eight patients found to have a macroadenoma were also satisfactorily treated with surgery. Two patients had a lesion other than a prolactinoma, and in six a tumour could not be found at operation; four of these last eight patients had a normal serum prolactin concentration after operation. Recurrent hyperprolactinaemia was rare, occurring in only three patients in the series overall; among the 32 patients followed up for more than five years only two of the 22 whose operation had initially been successful developed recurrent hyperprolactinaemia.

Adenoma↗

An excitatory and a depressant insect toxin from scorpion venom both affect sodium conductance and possess a common binding site.

Two insect selective toxins were purified by gel-permeation and ion-exchange chromatographies from the venom of the scorpion, Leiurus quinquestriatus quinquestriatus, and their chemical and pharmacological properties were studied. The first toxin (LqqIT1) induces a fast excitatory contraction paralysis of fly larvae and is about 40 times more toxic than the crude venom. It is a polypeptide composed of 71 amino acids, including 8 half-cystines and devoid of methionine and tryptophan, with an estimated molecular weight of 8189 and a pI value of 8.5. The second toxin (LqqIT2) induces a slow depressant, flaccid paralysis of fly larvae. It is composed of 72 amino acids, including 8 half-cystines, is devoid of proline methionine and histidine, and has an estimated molecular weight of 7990 and a pI value of 8.3. The contrasting symptomatology of these toxins is interpreted in terms of their effects on an isolated axonal preparation of the cockroach in current and voltage clamp conditions. LqqIT1 (0.5-4 microM) induced repetitive firing of the axon which was attributable to two changes in the sodium conductance, a small increase in the peak conductance and a slowing of its turning off. LqqIT2 (1-8 microM) caused a blockage of the evoked action potentials, attributable to both a strong depolarization of the axonal membrane and a progressive suppression of the sodium current. Neither toxin affected potassium conductance. The two toxins differ mainly in their opposite effects on the activatable sodium permeability. In binding assays to a preparation of insect synaptosomal membrane vesicles, the two toxins were shown to competitively displace the radioiodinated excitatory insect toxin derived from the venom of the scorpion, Androctonus australis [( 125I]AaIT), which strongly resembles, in its chemistry and action, the LqqIT1 toxin. The present two toxins have demonstrated a strong affinity closely resembling the AaIT, with KD values of 0.4, 1.9, and 1.0 nM for LqqIT1, LqqIT2, and AaIT, respectively. These data suggest the possibility that the excitatory and depressant insect toxins share a common binding site associated with sodium channels in insect neuronal membranes.

Amino Acids↗

Isolation from Cannabis sativa L. of cannflavin--a novel inhibitor of prostaglandin production.

The isolation from Cannabis sativa L. of an inhibitor of prostaglandin (PG) E2 production by cultured rheumatoid synovial cells is described. This agent, for which the name Cannflavin has been coined, is distinct from cannabinoids on the basis of isolation procedure, preliminary structural analysis and biological properties. The activity of Cannflavin has been compared with several established anti-inflammatory drugs and the major cannabinoids.

Anti-Inflammatory Agents↗

Structural correlations of phorbol-ester-induced stimulation of PGE2 production by human rheumatoid synovial cells.

Eight phorbol esters were studied for their ability to stimulate prostaglandin production in human rheumatoid synovial cells over the dose range 0.1 ng to 1.0 micrograms. These derivatives were based upon phorbol, 4-deoxyphorbol, and 12-deoxyphorbol nuclei. This activity was structurally dependent and, although it did not correlate with the actions of the same compounds to induce erythema in vivo, it did correlate with their ability to stimulate human lymphocyte mitogenesis. Stimulation of PGE2 production by a phorbol and a 12-deoxyphorbol analog was inhibited in this system by both indomethacin and dexamethasone.

Arthritis, Rheumatoid↗