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Biomedical subjects

A Coelho

Publications and source records attributed to A Coelho.

At least 19 recordsLinked to original sources
PubMed1992

Serum keratan sulfate levels in marathon runners.

The effect of strenuous joint loading on the metabolism of articular cartilage in man is not known. The development of a non-invasive immunoassay for the assessment of the catabolism of cartilage aggrecan has enabled us to quantify keratan sulfate (KS), a component of aggrecan, in the serum of fifteen male marathon runners. Serum KS was measured by an ELISA before and immediately after a marathon (42 km), as well as 48 hours after the completion of the race. The mean level at rest was similar to those previously reported for another population of age-matched males. There was no statistically significant difference in the serum level of KS at the three different readings. Further, there was no correlation between age, height, weight and performance time, and the serum level of KS at any of the three different times. We conclude that marathon running by carefully trained runners causes neither a transient nor a sustained increase in proteoglycan catabolism in articular cartilage.

Adult↗
PubMed1992

Psychiatric morbidity in patients with peripheral vestibular disorder: a clinical and neuro-otological study.

This study reports the psychiatric morbidity in 54 patients with objective evidence of peripheral vestibular disorder seen three to five years after their original referral. A third of the patients were free from vestibular symptoms at follow up and a further third had experienced some improvement. Two thirds of the patients had experienced psychiatric symptoms during this period, although only 50% were rated above the cut off point for significant psychiatric disturbance when interviewed. Panic disorder with or without agoraphobia and major depression were the commonest psychiatric diagnoses. Patients with classical "labyrinthine" symptoms had a more severe canal paresis than the rest, but the degree of the abnormalities in the neuro-otological tests was unrelated to outcome or to psychiatric morbidity. On the other hand, there was a significant correlation between the presence of vestibular symptoms and psychiatric morbidity, which in turn correlated with measures of anxiety, perceived stress and previous psychiatric illness.

Adolescent↗
PubMed1991

Observations on the initiation of sustained ventricular tachycardia by programmed stimulation.

We analyzed the initiation of sustained monomorphic ventricular tachycardia (VT) by programmed ventricular stimulation (PVS) in 50 consecutive patients who had clinical VT or aborted sudden cardiac death with remote myocardial infarction. In 25 of 50 patients, the first induced QRS complex of VT was morphologically identical to the succeeding QRS complexes of VT (type I). In 25 other patients, the first VT beat had a different morphology (type II). Type I had a significantly longer VT cycle length than type II (333 +/- 65 msec and 293 +/- 66 msec, P = 0.036). Type II VT initiation required more aggressive stimulation protocol than type I (type I: type II; number of extrastimulus required for induction 2.5 +/- 0.9 : 3.0 +/- 0.6, P = 0.026; shortest extrastimuli coupling interval 244 +/- 28 msec : 220 +/- 23 msec, P = 0.002). The interval between the last extrastimulus and the onset of the first VT beat was 408 +/- 88 msec in type I and 336 +/- 75 msec in type II (P = 0.004). Furthermore, there was good correlation between the VT cycle length and the interval from last extrastimulus to the onset of nonpaced beat in type I but not in type II.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1990

Serum keratan sulphate levels during prolonged rest.

Serum levels of keratan sulphate (KS) were measured by an enzyme-linked immunosorbent-inhibition assay on admission to hospital in 26 previously healthy young patients who had sustained fractures of the pelvis without involvement of the hips. The serum KS level was found to decrease during the period in hospital (5-6 weeks), but rose after return to ambulatory life (6-12 months). The results suggest that serum KS levels are related to rest.

Adolescent↗
PubMed1990

Brainstem potentials in the diagnosis of an acoustic neuroma. An unusual case of normal ipsilateral and abnormal contralateral responses.

An unusual case is presented of a patient with an acoustic neuroma, in whom the responses recorded with the usual derivation of ipsilateral recording and stimulation resulted in a normal response, whereas that derived contralaterally was abnormal. The patient was also reported to have a normal magnetic resonance scan although the tomograms revealed a widening of the internal auditory meatus and subsequent histology confirmed a schwannoma. Postoperatively the hearing was preserved and the brainstem responses showed a typical 'acoustic picture' with a delay of Waves III and V both ipsi and contralaterally. Subsequent testing showed an improvement in the latency of Wave V. Certain hypotheses are advanced regarding the mechanism involved in the latency differences observed between ipsi- and contralateral recordings, but the significance of abnormal prolongation of the latencies of certain components occurring independently in the contralateral response remains obscure. However, this patient's example clearly shows its value in clinical testing.

Audiometry, Pure-Tone↗
PubMed1989

Tn4527, a Tp Sp/Sm transposon related to Tn7 and flanked by IS1.

Tn4527 was isolated from a Salmonella typhimurium strain obtained in Brazil. Its size is 19.6 kb and it carries resistance to trimethoprim, spectinomycin, and streptomycin, as in the case of Tn7 (14 kb). A restriction analysis of the transposon shows regions of similarity to Tn7 mixed with extra DNA. The 2.6-kb and 2.2-kb HindIII fragments of Tn7, which encode transposition-related proteins, show homology to Tn4527. In contrast to Tn7, Tn4527 is flanked by direct repeats, which seem to be IS1's, as they have appropriate restriction sites and hybridize both to IS1 and to internal IS1 oligonucleotides.

Anti-Bacterial Agents↗
PubMed1988

Serum keratan sulfate levels in osteoarthritis patients.

Serum levels of keratan sulfate (KS), measured by an enzyme-linked immunosorbent-inhibition assay, were found to be significantly higher in 31 patients with hypertrophic osteoarthritis (OA) than those in 41 adults without joint disease. Seventy-seven percent of patients with OA, but only 12% of control subjects, had serum levels which were more than 1 SD above the mean of the control group. Following replacement of a single osteoarthritic hip joint, serum KS levels decreased, at first, in all patients. Subsequently, the concentration of serum KS progressively increased; 6 months following surgery, KS levels were similar or close to the preoperative levels in virtually all patients. The results suggest that patients with hypertrophic OA may have a generalized imbalance of cartilage proteoglycan metabolism. Measurements of serum KS are likely to prove most useful in studying this particular subset of patients with generalized OA.

Aged↗
PubMed1988

Careers of dentists undertaking a medical qualification.

The careers of doubly-qualified dentists have been re-examined, 12 years after the report by Henderson, Liversedge and James (1977). Three groups of medically qualified dentists were analysed. (a) those qualifying before 1960; (b) those qualifying between 1960 and 1975; (c) those qualifying since 1975. An increased proportion of those embarking on a medical qualification fail to return to a dental career, despite a stated intention to do so. There appears to be a 'wastage' to dentistry of approximately 40% of those dentists who subsequently obtain a medical qualification. Of those who do return, most practice hospital specialties at consultant level.

Adult↗
PubMed1987

Intraglomerular T cells and monocytes in nephritis: study with monoclonal antibodies.

Intraglomerular T cells, monocytes, total leucocytes and other mononuclear subsets were sought in renal biopsies from patients with glomerulonephritis, using monoclonal antibodies and immunoperoxidase techniques. Twenty-four biopsies with no significant glomerular proliferation on optical microscopy, thirty-two with only endocapillary hypercellularity, and twenty-one with extra capillary crescentic glomerular disease were studied. Few intra-glomerular leucocytes were seen in the non-proliferative group. In contrast, when compared with this group, biopsies with glomerular hypercellularity and particularly those with crescents showed increased numbers of intra-glomerular total leucocytes and monocytes/macrophages, as well as an excess of T lymphocytes and T cytotoxic/suppressor cells; T helper/inducer lymphocytes were significantly increased only in the crescentic group. Only small numbers of B lymphocytes and NK cells were found in all groups. The numbers of total glomerular T-cells and monocytes per glomerular cross section were highly correlated in the crescentic group. Only idiopathic IgA nephropathy failed to show a significant increase in the numbers of intra-glomerular leucocytes, in comparison with the non-proliferative group, Henoch-Schönlein purpura biopsies in contrast had an excess of both monocytes and T cell subsets. The finding of T lymphocytes as well as monocytes in glomeruli of proliferative nephritis suggests that cellular immune mechanisms may play a role in their pathogenesis, especially when crescents are present.

Antibodies, Monoclonal↗
PubMed1986

Tachyarrhythmias in young athletes.

Nineteen young athletes with documented symptomatic tachyarrhythmia were systematically evaluated. There were 15 men and 4 women, aged 14 to 32 years (mean 22 +/- 6). Documented tachyarrhythmias were paroxysmal atrial fibrillation in five patients, paroxysmal supraventricular tachycardia in five, paroxysmal ventricular tachycardia in eight (sustained in five, nonsustained in three) and ventricular fibrillation in one patient. Abnormal substrates were demonstrated in 15 (79%) of the 19 athletes: 5 had an anomalous atrioventricular (AV) pathway and 10 had heart disease (mitral valve prolapse in 9 patients and dilated cardiomyopathy in 1 patient). In 13 (68%) of the 19 athletes, all spontaneous attacks of tachyarrhythmia had started during strenuous exercise. Tachyarrhythmia that closely resembled clinical arrhythmia was induced by programmed cardiac stimulation in 13 athletes (68%) and was reproducibly provoked by treadmill exercise in 8 athletes (42%). In four of seven athletes with ventricular tachycardia, tachycardia closely resembling clinical arrhythmia was provoked by infusion of isoproterenol. In summary: young athletes can have any of several tachyarrhythmias; abnormal substrates can be demonstrated in many athletes with symptomatic tachyarrhythmia; and tachyarrhythmias in young athletes frequently occur during exercise.

Adolescent↗
PubMed1986

[Intracranial chondrosarcoma: report of a case].

A case of intracranial chondrosarcoma is reported. Its diagnosis can be suspected through the findings of a paraselar avascular tumor, sometimes with in specific calcifications, visualized as a isodense and contrast-enhancing mass by computed tomography, as observed in the case. Differential diagnosis may be difficult with chondromas and meningiomas. Surgical resection is the treatment of choice, with good results.

Brain Neoplasms↗
PubMed1986

[Value of aspiration biopsy of subcutaneous fat in amyloidosis].

Fine-needle aspiration of subcutaneous fat (FNAF) was performed in 24 patients, 12 with previously diagnosed amyloidosis presenting with proteinuria or nephrotic syndrome, and 12 presenting a nephrotic syndrome without amyloidosis on renal biopsy. FNAF was positive in 10 of 12 patients with amyloidosis (sensitivity: 83%) and negative in 12 of 12 patients with non-amyloid nephrotic syndrome (specificity: 100%). Considering a 2.5 to 10% prevalence of amyloidosis in adult patients with proteinuria or nephrotic syndrome, a positive FNAF is diagnostic of amyloidosis, and a negative FNAF rules out the diagnosis with a probability of 98 to 99%. FNAF is a simple and safe method which can be useful in patients who cannot undergo a renal biopsy.

Adipose Tissue↗
PubMed1984

Pharmacological observations in patients with nodoventricular pathways.

Three patients with accessory nodoventricular pathways and re-entry tachycardia are reported. In all three patients the accessory nodoventricular pathway formed the anterograde limb of the re-entry circuit while the His-Purkinje-atrioventricular node axis formed the retrograde limb of the tachycardia in two of the patients and a concealed accessory pathway formed the retrograde limb in the remaining patient. All three patients also manifested dual anterograde atrioventricular nodal pathways with conduction through the accessory nodoventricular pathways being associated with the atrioventricular nodal fast pathway. Type I antiarrhythmic drugs, especially disopyramide and quinidine, were effective for the treatment of the re-entry tachycardia because of their depressive action on the nodoventricular pathway. Beta blockers were also effective because of their action on the atrioventricular nodal portion of the re-entry circuit in one patient and most probably due to atypical (atrioventricular nodal like) properties of a retrogradely conducting accessory pathway in a second patient.

Adolescent↗
PubMed1983

The morphology of ascending aortic aneurysms.

To determine the frequency of morphologic abnormalities of the aorta, especially of the media, in patients with aneurysms of the ascending aorta, tissue specimens from surgically resected ascending aortic aneurysms of 339 patients were studied. Included were 232 men and 107 women; 53 (29 men, 23 women) had clinical signs of Marfan's disease. Features evaluated and graded included fragmentation of elastic fibers, cystic medial change, medial fibrosis, medial necrosis, atherosclerosis, periaortic fibrosis, and thickening of the vasa vasorum. Both elastic fragmentation and cystic medial change were present in a high percentage of patients. Cystic medial change was inversely correlated with increasing age of patients, especially in the group of patients without clinical evidence of Marfan's syndrome. Marked changes of these types in many younger patients without Marfan's syndrome could reflect a "tissue insufficiency" in early life that causes the aortic wall to weaken and dilate. Medial necrosis, fibrosis, and atherosclerosis were directly correlated with age. Hemodynamic events are considered to initiate injury and repair within the aortic wall. Dissection was more frequently seen with medial abnormalities than with atherosclerosis.

Adult↗
PubMed1983

Concordance and discordance of drug responses in atrioventricular reentrant tachycardia.

Whether the results of some drug studies could be used to predict the results of other drug studies was examined during serial electrophysiologic drug testing in patients with sustained atrioventricular reentrant tachycardia. The drugs studied were intravenous propranolol, 0.1 mg/kg; intravenous ouabain, 0.01 mg/kg; the combination of propranolol plus ouabain; intravenous procainamide, 0.75 to 1.5 g; oral quinidine, 1.2 to 2.4 g/day; and oral disopyramide, 0.8 to 1.6 g/day. Response was inability to induce sustained tachycardia after administration of a drug. Responses due to increased anterograde limb refractoriness. Six of 10 patients with response to propranolol plus ouabain versus 0 of 9 patients without response to this combination had response to propranolol alone (p less than 0.01). Seven of 14 patients with response to the combination versus 0 of 9 patients without response to the combination had response to ouabain alone (p less than 0.05). Responses due to increased retrograde limb refractoriness. Eight of 9 patients with response to procainamide versus 2 of 17 patients without response to this drug had response to quinidine (p less than 0.01). There was not a significant relation between response to procainamide and response to disopyramide, or between response to quinidine and response to disopyramide. Anterograde limb versus retrograde limb. There was not a significant relation between response to propranolol plus ouabain and response to any class I drug. In conclusion, there are relations between drug responses during electrophysiologic studies in patients with atrioventricular reentrant tachycardia. Thus, it should be possible to simplify these studies.

Adolescent↗