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Biomedical subjects

M George

Publications and source records attributed to M George.

At least 145 records · Page 8Linked to original sources
PubMed1992

Helicobacter pylori. Its role in the pathogenesis of peptic ulcer disease in a new animal model.

The association and causative role of Helicobacter pylori infection of the stomach with gastric ulcer, duodenal ulcer, non-ulcer dyspepsia, and gastritis has remained controversial. The authors studied the effects of daily intragastric administration of H. pylori suspension in saline (10(8) CFU/ml) and bacteria-free filtrates of saline H. pylori suspensions in 85 Sprague-Dawley rats (weight, 150 to 200 g) with normal mucosa and with surgically produced experimental gastric ulcers. Group I rats (n = 30) with pre-existent experimental gastric ulcers received H. pylori suspension (ATCC 43504, 10(8) CFU/ml); Group II rats (n = 20) with experimental gastric ulcers received bacteria-free H. pylori filtrates; Group III rats with ulcers (n = 20) received saline alone; and Group IV control rats (n = 15) without ulcers received intact H. pylori organisms in suspension (ATCC 43504, 10(8) CFU/ml). At death, ulcer surface areas were measured with a dissecting microscope. Full-thickness sections were obtained for quantitative and qualitative histologic parameters, including the area of remaining mucosal necrosis; characteristics and cellular composition of restored mucosal architectures; and presence or absence of inflammation including counts of neutrophils and lymphocytes. H. pylori organisms were identified within the surface mucus and crypts using routine, special, and immunohistochemical stains. Our results indicate that the continued presence of either intact H. pylori organisms or bacteria-free H. pylori filtrates in the stomachs of rats with pre-existent gastric ulcers resulted in delayed healing of the ulcers and persistence of chronic active inflammation. Daily administration of suspensions of H. pylori organisms to sham-operated rats with intact gastric mucosa, however, resulted in no ulceration or inflammation despite identification of surface H. pylori organisms at death. The authors conclude that H. pylori alone causes little or no effect on an intact gastric mucosa in the rat, that either intact organisms or bacteria-free filtrates cause similar prolongation and delayed healing of pre-existing ulcers with active chronic inflammation, and that the presence of predisposing factors leading to disruption of gastric mucosal integrity may be required for the H. pylori enhancement of inflammation and tissue damage in the stomach.

Animals↗
PubMed1992

Peripartum cardiac failure in The Gambia.

Twenty-seven patients with peripartum cardiac failure were seen at the Royal Victoria Hospital, Banjul over a 2-year period while one further patient presented 6 months after delivery with a cerebral embolus secondary to a dilated cardiomyopathy. Five (18%, P less than 0.001) patients had twin pregnancies. Seventeen (63%) patients attended for follow-up, of whom eight had evidence of continuing cardiac dysfunction and required treatment with diuretics; two patients were known to have died. In five asymptomatic patients the electrocardiogram had reverted to normal and three patients had further pregnancies without relapse. The bipolar distribution of onset of symptoms in relation to pregnancy was suggestive of two different pathological processes. There was no evidence that cultural habits played any significant part in the aetiology of peripartum cardiac failure in The Gambia.

Adolescent↗
PubMed1992

Haemodynamic and biological effects of intravenous milrinone in patients with a low cardiac output syndrome following cardiac surgery: multicentre study.

The haemodynamic and biological effects of intravenous milrinone were studied in 24 adult patients with a low cardiac output syndrome following cardiac surgery. The patients received a milrinone bolus of 50 micrograms kg-1 over 10 min followed by a 0.375-0.750 micrograms kg-1 min-1 infusion over 48 h. After the first hour of treatment, an increase in cardiac index, systolic index and left ventricular stroke work index, and a decrease in right and left loading pressures, pulmonary artery pressure, systemic vascular resistance and pulmonary vascular resistance were observed while heart rate and systemic arterial pressure were not modified. These haemodynamic effects were maintained over the 48 h of treatment and persisted 3 h after discontinuation of treatment. Milrinone, which possesses inotropic and vasodilatory effects, increased cardiac performance and corrected the low cardiac output in all patients.

Adult↗
PubMed1991

The use of cerebral activation procedures with single photon emission tomography.

Single photon emission tomography allows the imaging of dynamic brain functioning. The use of cerebral activating procedures within the scan protocol enables investigation of the mechanisms involved in specific brain functions in health and disease. Activation studies involve the comparison of at least two data sets describing brain activity generated in conditions that differ for the specific function in question. When designing an activation study, decisions regarding methodology include: the nature of the activation regime, the tracer-ligand utilized, the SPET instrument and the manner of subsequent data analysis. These issues are discussed in this review, both theoretically and with reference to published studies. Means of activating particular cerebral structures and functions are reviewed, as are the limitations of the techniques with respect to temporal and spatial resolution and the potentially confounding nature of preconceived ideas regarding the mechanisms of brain function.

Brain↗
PubMed1991

Helicobacter pylori affects the quality of experimental gastric ulcer healing in a new animal model.

Helicobacter pylori has been implicated in the genesis of human gastritis, dyspepsia, and peptic ulcers. However, its influence in the quality of experimental gastric ulcer healing has not been previously investigated. Standardized gastric fundic ulcers were produced in 50 male Sprague-Dawley rats (150-200 g) by a 4 mm in diameter focal, serosal application of 100% acetic acid. Thirty rats were administered 2 ml H. pylori suspension (urease producing, ATCC 43504) in normal saline (10(8) CFU/ml) 2x/day for 7 days. Twenty rats (controls) received 2 ml normal saline 2x/day for 7 days. Gastric ulcer surface area was measured under a dissecting microscope and mucosal specimens were obtained for qualitative and quantitative histology. No gross or microscopic duodenal abnormalities were identified at sacrifice. Ninety percent of control rats showed grossly and microscopically entirely healed ulcers. The remaining 10% showed partially reepithelialized ulcers (area, 0.78 to 1.77 mm2; mean, 1.27 +/- 0.7 mm2). The grossly "healed" mucosa demonstrated marked dilatation of gastric glands lined with mature surface epithelial cells. Parietal cells were scanty (5-10% of all cells). One hundred percent of the H. pylori-exposed rats showed persistence of chronic active ulcers (area, 1.76 to 19.63 mm2; mean, 8.95 +/- 6.15 mm2). The ulcer beds were infiltrated by acute and chronic inflammatory cells, abundant fibroblasts, and capillary networks. The raised ulcer borders were characterized by dilated glands lined by mature surface epithelial cells. Various special stains demonstrated the presence of H. pylori in the surface mucus and within the crypts.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetates↗
PubMed1991

[Hemodynamic effects of amrinone in low cardiac output after mitral valve replacement].

The efficacy of amrinone was assessed in the treatment of low cardiac output states occurring within 24 h after mitral valve replacement in an open prospective trial. It included 7 women and 5 men, aged 58 +/- 10 years. Four patients had also had simultaneous aortic valve replacement. Patients entered in the study if their cardiac index (CI) remained less than 2.2 l.min-1.m-2 after pulmonary wedged pressure (Ppw) had been increased to at least 15 mmHg, the patient having a temperature greater than 36 degrees C. Amrinone was given so as to increase Cl by at least 30% and to decrease Ppw by at least 30%. Patients were given a mean of 1.5 mg.kg-1 amrinone during the first hour, followed by a constant rate infusion of 9 +/- 3 micrograms.kg-1.min-1 over at least 24 h. The usual haemodynamic parameters were measured and calculated before giving amrinone, and after 1, 3, 6, 24, and 48 h. After 1 h of treatment, systolic arterial pressure, cardiac index, systolic index and left ventricular stroke work increased by 22, 42, 23, and 47% respectively, whilst Ppw decreased by 27% (p less than 0.01). Heart rate rose and systemic vascular resistance decreased but not significantly. Right atrial pressure, right ventricular stroke work, pulmonary artery pressure and pulmonary vascular resistance did not change. These effects were all maintained throughout the 48 h infusion. Amrinone had to be replaced by another agent (a beta-agonist) in 3 cases because of arrhythmia, lack of efficacy or thrombocytopaenia. In this setting, amrinone increased left ventricular performance with little effect on the right ventricle.

Adult↗
PubMed1991

A phase I trial of 14-day continuous intravenous infusion mitoxantrone.

Based on clinical evidence that prolonged exposure to anti-neoplastic agents may ameliorate dose-limiting toxicity while facilitating anti-tumor activity, we conducted a phase I trial of 14-day continuous intravenous infusion mitoxantrone. Study objectives were to: (1) determine the maximally tolerated dose for phase II trials; (2) determine the incidence and severity of side effects; and (3) study the pharmacokinetics of continuous infusion mitoxantrone. Sixteen patients with drug-resistant advanced cancers were entered into the trial. Three or more patients were treated at each dose level (1.0, 1.25, and 1.5 mg/m2/day) for a total of 33 courses (mean 2.1 courses/patient, range, 1-4). Courses were repeated every 4 weeks. The maximally tolerated dose (MTD) was found to be 1.5 mg/m2/day. At this dose four of six patients had grade III or IV leukopenia (mean WBC nadir 1900/microliters, range, 800-3600/microliters). Other toxicities were grade I or II stomatitis (two patients), grade I diarrhea (one patient), and grade I nausea (one patient). Renal and hepatic toxicity were not observed. No alopecia or infectious complications occurred. Pharmacokinetic studies were performed using high-performance liquid chromatography (HPLC). Steady-state plasma levels at the 1.5 mg/m2/day dose were reached by 48 h, with a mean steady-state plasma concentration of 3.2 +/- 0.7 ng/ml, mean total body clearance of 340 +/- 79 ml/min/m2, and mean area under the plasma disappearance curve (AUC) of 955 +/- 185 micrograms h/l. No responses were observed, although no patients with mitoxantrone-sensitive tumors were treated.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Study of high doses of carboplatin as a first choice in the therapy of advanced ovarian cancers].

Thirty female patients with ovarian cancer of poor prognosis were included in a chemotherapy trial using high dose IV carboplatin--800 mg/m2 every 5 weeks. The subjects had three to six cycles prior to second laparotomy. Twenty-eight patients were assessable. There was no neurological, auditory or renal toxicity. Limiting toxicity was haematological, the mean neutrophil count was less than 650 mm3 and the mean platelet count less than 30,000/mm3. No death occurred from toxicity. The clinical response rate was 67%, and the surgical response rate 53.5%, with 15% complete histological responses. Survival at 18 months is 36%. A trial concerning 36 patients treated with an association of carboplatin at the same dose combined with cyclophosphamide has just been completed and the results are being analyzed.

Adenocarcinoma↗
PubMed1990

Rural community mental health consumer satisfaction and psychiatric symptoms.

This study examined the impact of therapy on psychiatric symptoms and consumer satisfaction in a rural community mental health center. Utilizing the Brief Symptom Inventory (BSI) and an evaluation of service questionnaire (EOS), designed by the authors, results indicated positive outcomes for both measures (88 subjects). Small but significant correlations were obtained for the BSI and EOS (r's .29 to .59). Implications for future research and treatment are discussed focusing on time of intervention and symptom quality.

Adaptation, Psychological↗
PubMed1990

Relationship between preoperative amiodarone treatment and complications observed during anaesthesia for valvular cardiac surgery.

Two groups of ASA physical status class III and IV patients undergoing cardiac surgery were reviewed in an attempt to obtain more conclusive data concerning dangerous interactions between amiodarone and anaesthesia. The amiodarone group (Group 1, ten patients, cumulative dose 10 g) was compared with a control group (nine patients, Group 2). Amiodarone (A) and desethylamiodarone (NA) concentrations in plasma and myocardium were measured and haemodynamic and antiarrhythmic effects were analysed. Throughout anaesthesia haemodynamic status was similar in both groups. No correlation was found between A/NA and cardiac index changes. No patients needed intraaortic blood pressure augmentation or developed low systemic vascular resistances. Pacemaker dependency was similar in both groups and there was no evidence of increased anaesthetic risk. An excellent antiarrhythmic effect was obtained during the postoperative period. We conclude that preoperative treatment with amiodarone is effective against postoperative arrhythmias.

Adult↗
PubMed1990

Phase II trial of intraperitoneal mitoxantrone in the management of refractory ovarian cancer.

To define both the toxicity and efficacy of intraperitoneal mitoxantrone in the treatment of refractory ovarian carcinoma, 31 patients were entered onto a phase II trial of this agent delivered in a 2 L treatment volume on a monthly basis. Due to excessive local pain at the initial dose level (30 mg/m2), the amount of drug delivered with each treatment course was reduced to 20 mg/m2. Despite this reduction, 74% of patients required narcotic analgesia during treatment. In addition, there were four episodes of bowel obstruction (one requiring surgical intervention) during therapy, and two patients developed bowel obstruction and intraabdominal abscesses following the completion of treatment. Six of 18 evaluable patients (33%) whose largest tumor diameter was less than or equal to 1 cm at protocol initiation experienced surgically documented responses, compared with one of 11 patients (9%) whose largest tumor was greater than 1 cm in diameter. If the two patients exhibiting what we called a mixed response to treatment are included, seven of 21 patients previously treated with intraperitoneal cisplatin responded to this treatment program, including four patients who had failed to respond to intraperitoneal cisplatin. No responding patient has demonstrated clinical evidence of relapse with a median follow-up of 7 months (range, 3+ to 13+ months) from response laparotomy. Intraperitoneal mitoxantrone is an active treatment program in patients with small-volume refractory ovarian carcinoma, but local toxicity can be severe. Due to the toxicity encountered with this specific program, its use cannot be recommended for standard clinical practice. However, in view of the activity observed in refractory ovarian carcinoma, including responses in patients who had previously failed intraperitoneal cisplatin, it is important to continue to explore alternative therapeutic regimens using intraperitoneal mitoxantrone to reduce local toxicity while maintaining or improving efficacy.

Carcinoma↗
PubMed1990

Randomized comparison of cyclophosphamide, doxorubicin and cisplatin (CAP) versus cyclophosphamide and doxorubicin (CA) for the treatment of advanced ovarian cancer (ADOVCA). A EORTC Gynecological Cancer Cooperative Group Study.

The possible advantage of adding cisplatin (P) to cyclophosphamide (C) + adriamycin (A) in the management of stages III and IV ovarian cancer of epithelial origin was tested in a trial in which 149 patients were randomized to receive, after initial surgery, either CAP (C = 600 mg/sqm, A = 45 mg/sqm, P = 50 mg/sqm) or CA (C = 600 mg/sqm, A = 45 mg/sqm) every 4 weeks for 6 to 12 cycles, at which time follow-up laparotomoy was to be performed in responding or clinically disease-free patients. Fifteen patients were not included in the final analysis and the remaining 134 patients were considered fully or partially evaluable and are used in analysis of response and survival. The complete and partial response rates were 45.6% in the CAP arm and 45.4% in the CA arm, but the CAP regimen is of special importance in patients with bulky disease. Median survival CAP = 24 m and CA = 24.2 m), time to progression and survival was found not significantly different when CAP and CA were compared. However, more patients in the CA regimen had no macroscopic disease left after surgery than in CAP regimen (11 versus 6) and more patients in the CAP arm dose reductions and schedule delays than in the CA arm (61.1% versus 38.2%).

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

[Comparison of the hemodynamic effects of dobutamine and enoximone in the treatment of low cardiac output after valvular surgery].

Forty patients developed low cardiac output states after surgery for mitral valve disease or with associated cardiac disease and were randomly allocated to two treatment groups, one group to receive Dobutamine (D) and the other Enoximone (E), a phosphodiesterase inhibitor. Haemodynamic assessment covered a 24 hour period but treatment was continued for as long as was necessary. An improvement was observed from the 15th minute of treatment. At the second hour, the cardiac index had increased by 55% in Group E and by 59% in Group D whilst the heart rate increased by only 12% in Group E compared to 30% in Group D. The right and left heart filling pressures decreased by 25 to 27% in the 2 groups. The systemic arterial resistances fell by 36 to 37% without any significant changes in systemic or pulmonary arterial pressures. No significant difference was demonstrated in the haemodynamic responses to Dobutamine and Enoximone in this study. The duration of treatment was significantly shorter in Group E than in Group D (59 +/- 22 hrs vs 86 +/- 49 hrs) as was the patient's stay in the intensive care unit (92 +/- 37 hrs vs 155 +/- 129 hrs). The duration of assisted ventilation was the same in the two groups. These results suggest that Enoximone is as effective as Dobutamine in the treatment of low cardiac output after mitral valve surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Arrhythmia in patients with low cardiac output after valvular surgery. Randomized, double-blind comparative study of dobutamine versus enoximone].

Forty patients with low cardiac output (cardiac index less than 2.2 l/mn/m2 and pulmonary wedge pressure greater than 15 mmHg) after valvular surgery were randomised into two groups. Patients in Group 1 were given 5 to 10 micrograms/Kg/mn of Dobutamine (D) and those In Group 2 a bolus of Enoximone (E) 1 mg/kg followed by an intravenous infusion of 5 to 10 micrograms/Kg/mn. Holter ECG monitoring over 42.65 +/- 6.02 hrs (24-48 hours) was obtained and interpreted blindly in 37/40 patients (19 Group D and 18 Group E). The results were analysed by the t and X2 tests. A p value of less than .05 was considered statistically significant. The two groups were comparable. No deaths occurred during the protocol period. The total duration of inotropic therapy (86 +/- 49 hours) and the period spent in the intensive care unit (155 +/- 129 hours) were longer in Group D than in Group E (60 +/- 23 hrs and 92 +/- 37 hrs, respectively; p less than .05). Antiarrhythmic therapy was used more often in Group D (4 patients) than in group E (1 patient) (p = 0.09).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗