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Biomedical subjects

P Muiesan

Publications and source records attributed to P Muiesan.

52 records · Page 3Linked to original sources
PubMed1995

Orthotopic liver transplantation for hepatic-based metabolic disorders.

Between January 1989 and June 1993, a total of 470 liver transplantations were performed at King's College Hospital. Thirty-seven transplantations were performed in 34 patients with liver-based metabolic disease. There were 16 females and 18 males with a median age of 19 years (range 1 month to 62 years). There were 14 patients under 16 years of age. The indications for liver transplantation were Wilson's disease (n = 16), alpha 1-antitrypsin deficiency (n = 10), tyrosinaemia (n = 2), primary hyperoxaluria type 1 (PH1; n = 2), congenital haemochromatosis (n = 1), familial amyloidotic polyneuropathy (FAP; n = 1, familial hypercholesterolaemia) (n = 1) and Crigler-Najjar syndrome type I (CNS1; n = 1). These included two patients who received combined heart-liver grafts for familial hypercholesterolaemia and FAP, respectively. Two patients received combined liver-kidney transplants for PH1. There were four deaths: from sepsis (n = 2), acute hepatic vein obstruction in a left lateral segment graft (n = 1) and portal vein thrombosis with liver necrosis (n = 1). Three patients were retransplanted, one for chronic rejection and two for hepatic artery thrombosis, giving an overall graft survival of 81% and patient survival of 88% (30/34), at a mean follow-up of 34 months (range 10-64 months).

Acute Disease↗
PubMed1995

Arterial spontaneous rhythmic contractile activity in humans and rats: spectral analysis and regulatory mechanisms.

OBJECTIVE: Many experimental observations have demonstrated the presence of spontaneous cyclic vasomotor activity (CVA) in large and small arteries. This study aimed to evaluate the characteristics of spontaneous CVA in rat and human resistance arteries, and to investigate its possible interference with the evaluation of sympathetic activity by means of spectral analysis of blood pressure in vivo. DESIGN AND RESULTS: In study 1 we examined small mesenteric arteries of spontaneously hypertensive rats and Wistar-Kyoto rats, as well as small omental arteries of normotensive subjects and hypertensive patients (Mulvany and Halpern technique). CVA was enhanced by the agonists of nitric oxide release, and was abolished by the inhibitors of nitric oxide or cyclic GMP synthesis. A potassium channel, which is barium- and zinc-sensitive and tetraethylammonium-insensitive, seems to play a crucial role in the genesis of CVA. In rats and in humans the frequency of CVA fell exactly in the frequency band ('low frequencies') of power spectral analysis of blood pressure usually considered to be an 'index of sympathetic activity'. In study 2, a power spectral analysis of blood pressure variability before and after intra-arterial infusion of noradrenaline or acetylcholine was performed in 18 patients with mild-to-moderate hypertension. The absolute and normalized spectral power of the low-frequency systolic blood pressure peak increased remarkably after noradrenaline and acetylcholine infusion, while its central frequency shifted from 0.10 Hz to approximately 0.06 Hz, exactly the frequency of CVA observed in vitro. CONCLUSIONS: A potassium channel appears to be involved in the genesis of CVA. Also, CVA might contribute to the blood pressure variability independently of the autonomic nervous system activity, and thus probably plays a role in the genesis of the low-frequency peak in the rat and in humans.

Acetylcholine↗
PubMed1995

Liver transplantation for neonatal haemochromatosis.

Two cases of neonatal haemochromatosis, a rare and often fatal metabolic disorder, presenting with acute liver failure, are reported. Both presented in the first week of life with hypoglycaemia, jaundice, and coagulopathy, with rapid deterioration of liver function. Both received a transplantation using reduced liver grafts. One child was well 18 months later. Few survivors have been reported and despite the difficult perioperative management, liver transplantation is the best treatment for neonatal haemochromatosis.

Female↗
PubMed1995

Media: lumen ratio in human small resistance arteries is related to forearm minimal vascular resistance.

BACKGROUND: For the evaluation in humans of structural alterations in resistance arteries, most studies have used an indirect index, the measurement of minimal vascular resistance (mean blood pressure divided by maximal postischaemic blood flow) in suitable vascular beds. A sensitive and specific micromyographic technique was recently made available for the study of human small resistance arteries. Whether a correlation really exists between results obtained with the two techniques has not yet been investigated. OBJECTIVE: To evaluate both forearm minimal vascular resistance and media:lumen ratio of omental or subcutaneous small arteries in normotensive subjects and hypertensive patients. DESIGN AND METHODS: Thirty-four individuals were included in the study (age range 35-74 years; 24 hypertensive, 10 normotensive). Twenty-five had elective abdominal surgery and nine hypertensive patients had a gluteal biopsy. Omental and subcutaneous small arteries were dissected and mounted on a wire micromyograph (Mulvany's technique), and media:lumen ratio and media thickness were measured. The dose-response curve to noradrenaline was constructed at cumulative concentrations from 3 x 10(-9) to 3 x 10(-5) mol/l. Venous occlusion plethysmography was used to measure blood flow in the forearm, and minimal vascular resistance was calculated from mean blood pressure and postischaemic maximal blood flow (13 min ischaemia plus exercise). RESULTS: A statistically significant correlation was found between media:lumen ratio and minimal vascular resistance (r = 0.74, P < 0.001) as well as between media:lumen ratio and systolic (r = 0.44, P < 0.01) and diastolic (r = 0.38, P < 0.05) blood pressures. Similar correlations were observed between media thickness and systolic and diastolic blood pressures. Small arteries from hypertensive patients had a significantly increased reactivity to noradrenaline (by analysis of variance) compared with those from normotensive subjects, in terms of wall tension but not of active media stress. CONCLUSIONS: The present study demonstrated that the media:lumen ratio of small resistance vessels is significantly related to forearm minimal vascular resistance, suggesting that direct and indirect evaluations of vascular morphology will give similar results.

Adult↗
PubMed1994

Unusual localizations of hydatid disease: a 18 year experience.

The Authors report their experience with rare localizations of hydatid cysts during a period of 18 years. In 8 patients (14%) other organs than liver or lungs were involved: in particular one case of hydatid cyst of the spleen, one of the pancreatic area and one of the soft tissue of the back presented as primary locations. In 5 patients the disease of the liver was associated to hydatid cysts in other sites: 3 multiple peritoneal localizations, one in the abdominal rectus muscle and one of the gallbladder. Four cases (10% of the patients with liver disease) of cyst ruptures in the biliary tree were reported. In all cases differential diagnosis was more challenging than usual, but imaging devices combined with immunobiological tests could solve the diagnostic problem. Surgical treatment was as radical as possible considering the benign character of the disease. Postoperative results were satisfying: no recurrence but one was found at follow up.

Adolescent↗
PubMed1991

Hydatid disease of the liver: long term results of surgical treatment.

Many surgical techniques have been used in the management of the hydatid disease of the liver. The aim of the treatment should be to minimize the high risks of complication and recurrence. The Authors reviewed the records of 33 consecutive cases of hydatid disease of the liver surgically treated during a 6 year period (1974-1979) to determine complications and long term results (10 years) of the different surgical procedures applied. Partial pericystectomy with tube drainage was the most common treatment (30/49 cysts) followed by total pericystectomy (15/49) and partial liver resection (4 cases). Complication rates were 13.3%, 6.6% and 0% respectively. There was no perioperative mortality. In 1989 all patients were investigated for cystic recurrence: it was possible to study by CT scan or abdominal US 23 patients. Only three of them showed an asymptomatic recurrent disease. They had undergone partial pericystectomy in 1974 (2 cases) and 1977 (1 case) for recurrent hydatid disease of the right hepatic lobe and, in one case, even of the rectus muscle. Complication and recurrence rates seem to be higher with conservative surgical procedures compared to more radical treatment, but indiscriminate application of total pericystectomy or major liver resection may be followed by a higher incidence of major postoperative complications and mortality. Therefore, total pericystectomy or wedge resection were performed only for peripheral cysts since we believe liver resection for hydatid cyst is a very radical approach taking into account the type of disease.

Adolescent↗
PubMed1990

[Carotid thromboendarterectomy in old age].

Data obtained in 323 carotid bifurcation endarterectomies and in 77 patients affected by extracranial internal carotid artery stenosis not operated, have been analyzed in relation to patients' age: Group 1 less than or equal to 69 years old (268 cases operated on and 59 not operated), and Group 2 greater than or equal to 70 years old (55 cases operated on and 18 not operated). Among the operated patients, the most important anaesthetic risk factors, the type of neurological symptoms, and the diameter of the lesion did not turn out significantly different between the two age groups, except for the patients operated on because of stenoses less than or equal to 50% of carotid lumen reduction (42 cases in Group 1 and 1 case in Group 2, p less than 0.001). The overall operative mortality rate was 1.8% (6/323 carotid endarterectomies): 1.5% in Group 1 (4/268 cases, 2 due to stroke and 2 to heart disease), and 3.6% in Group 2 (2/55 cases, both due to stroke) (N.S.). The overall neurological morbidity was 0.6%, owing to 2 strokes both found in Group 2 (3.6% of patients greater than or equal to 70 years). Therefore, the overall incidence of fatal and non fatal stroke was 1.8% (6/323 carotid endarterectomies): 0.7% (2 cases) in Group 1, and 7.3% (4 cases) in Group 2 (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1989

Influence of contralateral carotid artery on neurologic outcome after carotid endarterectomy.

The discrepancy in the literature about the immediate results after carotid endarterectomy in the presence of occluded or seriously stenotic contralateral carotid artery, has encouraged a retrospective study on 230 patients subjected to 255 carotid endarterectomies. 63 operations (group 1) were carried out in the presence of occluded contralateral carotid artery (40 operations) or of seriously stenotic contralateral carotid artery (23 operations). In the remaining 192 operations (group 2) the contralateral carotid artery was normal or not significantly stenotic (less than 60% of diameter reduction). The indication for surgery and age and sex distribution were similar in the two groups. No operations were performed during acute stroke. Patients with previous stroke underwent surgery only after at least 1 month from the onset of symptoms, in stable neurological conditions. All the patients were operated on under general anesthesia and with systemic heparinization; the indication for intraluminal shunt was made on the basis of clinical evaluation, of back pressure value and, in 106 operated cases of somatosensory cortical evoked potentials. At the end of every operation, ultrasonographic and/or angiographic instrumental controls were carried out. No statistically significant difference was evidenced in the incidence in groups 1 and 2 of postoperative transitory neurological insufficiency (both 3.2%, P greater than 0.8), of permanent neurological insufficiency (0% and 1%, P greater than 0.9), of mortality because of neurological (3.2% and 1%, P greater than 0.5) and non neurological causes (1.6% and 0%, P greater than 0.1).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMedDate not supplied

[The role of magnetic resonance in the follow-up of aortofemoral prosthetic reconstructions].

The authors report their experience with the use of Magnetic Resonance (MR) in the follow-up of patients undergone aortofemoral bypass or substitution procedures for aneurysmal and/or steno-occlusive lesions of the aortoiliofemoral vascular bed. Twenty-eight patients, at least 2 years from aorto-bifemoral revascularization were evaluated by means of coronal and parasagittal MR planes (mean follow up 78.9 months). One exam over 28 was found to be not diagnostic; whereas the technique showed great usefulness in the morphological and haemodynamic evaluation of each of the graft sites explored (proximal anastomosis, graft body and limbs, femoral anastomosis and periprosthetic tissues) in the remaining 27 cases. The use of this method, in spite of some setting up problems peculiar to the type of examination, according to the authors is very promising because of the chance to obtain morphological and functional data at once and because of the interesting current and future developments of this diagnostic device.

Anastomosis, Surgical↗