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Biomedical subjects

G Mathew

Publications and source records attributed to G Mathew.

At least 37 records · Page 2Linked to original sources
PubMed1996

Wound metastases following laparoscopic and open surgery for abdominal cancer in a rat model.

The recent application of laparoscopic resection techniques to malignant disease has raised safety concerns due to metastasis to surgical access wounds. The significance and incidence of this problem are controversial. In the present study a rat model, in which an implanted tumour was lacerated, was used to investigate whether application of laparoscopic techniques for malignant abdominal disease leads to an increased risk of tumour dissemination and implantation within the peritoneal cavity, and abdominal wall wounds. Malignant cells were implanted into the abdominal wall of 42 rats, resulting 7 days later in the growth of a tumour measuring 20-25 mm in diameter. There were three control groups: no surgery (n = 6); blunt manipulation of the tumour laparoscopically (n = 6); and blunt manipulation of the tumour at laparotomy (n = 6). Twenty-four rats underwent surgical laceration of the tumour capsule at either laparoscopy (n = 12) or laparotomy (n = 12). All rats were killed 1 week later, and examined for macroscopic evidence of tumour metastasis. The abdominal surgical wounds were excised for independent microscopic examination by a histopathologist. Growth of the primary tumour was greater in rats that had an operation than in unoperated controls, and was greater after laparotomy. However, wound metastases were five times more likely after laparoscopic tumour laceration than after the same procedure through an open incision (ten of 12 rats versus two of 12, P = 0.0033). Wound metastases following laparoscopic tumour manipulation are an important and real problem, with significant implications for the application of laparoscopic techniques to excise malignant disease in humans.

Abdominal Muscles↗
PubMed1996

Changes in fibrinogen levels in patients undergoing open and laparoscopic Nissen fundoplication.

BACKGROUND: Venous thromboembolic complications may be more common after laparoscopic surgical techniques, possibly due to changes in venous flow and blood coagulability. METHODS: This study assessed fibrinogen, cross-linked fibrin degradation products (D-dimer), prothrombin international normalized ration (INR), activated partial thromboplastic time (APTT) and platelets, during and after both open and laparoscopic Nissen fundoplication to determine whether coagulability is increased by the laparoscopic approach. RESULTS: Seven patients underwent open and thirteen underwent laparoscopic Nissen fundoplication. Fibrinogen levels following open fundoplication fell from 2.8 +/- 0.3 g/L pre-operatively to 2.0 +/- 0.3 g/L following skin incision, and then increased to 4.1 +/- 0.4 g/L on the first postoperative day. Similar changes in fibrinogen occurred following laparoscopic fundoplication (2.7 +/- 0.2, 2.5 +/ 0.2 and 3.8 +/- 0.4 g/L, respectively). No significant changes in the other coagulation indices were observed. CONCLUSIONS: These results demonstrate hypercoagulability on the first postoperative day, irrespective of the operative technique. No differences between the results following laparoscopic and open fundoplication were demonstrated.

Adult↗
PubMed1996

Laparoscopic surgery for gastro-oesophageal reflux: beyond the learning curve.

From September 1991 to October 1995, 320 Nissen fundoplications were undertaken laparoscopically by 12 surgeons at a single institution. To assess the performance of the procedure in the hands of five 'experienced' surgeons, the first 20 procedures performed by each surgeon or surgical trainee were excluded, providing a group of 174 patients for review. A short loose 360 degrees fundoplication was performed in all instances, with short gastric vessel division performed in 35.0 per cent of patients and hiatal repair in 66.7 per cent. Median operating time was 80 (range 30-210) min and median postoperative stay was 3 (range 1-19) days. Sixteen procedures (9.2 per cent) could not be completed laparoscopically and required conversion to open surgery. Some 144 patients were reviewed by a scientific officer 3 months after surgery, 85 at 12 months, and 32 at 2 years, using a standard clinical questionnaire. All but one were free from reflux symptoms, although 20.1 per cent reported some dysphagia at 3 months' follow-up; this figure declined to 11 per cent at 12 months and 6 per cent (two of 34 patients) at 2 years. At each follow-up interval, 91 per cent of patients were satisfied with the outcome of the surgery. Objective testing with oesophageal motility (75 patients) and barium swallow (113) studies 3-6 months after surgery confirmed the clinical outcome. Complications occurred in nine patients (5.2 per cent); four (2.3 per cent) of these required a subsequent operation within 30 days of surgery for bleeding (one patient), paraoesophageal herniation (one) and dysphagia (two). A further procedure was necessary in six other patients (3.4 per cent) for late problems, including paraoesophageal herniation (two), hiatal stenosis (three) and gastric obstruction (one). Revision was performed laparoscopically in two patients. The clinical results of laparoscopic Nissen fundoplication by 'experienced' laparoscopic surgeons were comparable with those of open surgery.

Adolescent↗
PubMed1995

Impact of laparoscopic cholecystectomy in a major teaching hospital: clinical and hospital outcomes.

OBJECTIVE: To compare the clinical, training and cost implications of laparoscopic cholecystectomy with open cholecystectomy. SETTING: A university teaching hospital. DESIGN: A retrospective review of all patients who underwent cholecystectomy in 1989, before the introduction of the laparoscopic technique, and in 1993, after the learning curve for laparoscopic cholecystectomy had been overcome. MAIN OUTCOME MEASURES: Surgical indications, feasibility of laparoscopic approach, type of surgeon, operating time, hospital stay, postoperative complications, and cost analysis. RESULTS: 240 cholecystectomies were performed in 1989 and 293 in 1993. This is a 22% increase in overall workload and includes a significant increase (85%; P < 0.0001) in elective caseload. In 1993, 89% of patients underwent laparoscopic surgery, with conversion to open cholecystectomy in 6.8% of elective patients and 33% of emergency patients. Surgical indications remained the same, as did the time from diagnosis to cholecystectomy. There were significant changes in median length of hospital stay (from 10 days in 1989 to 4 days in 1993; P < 0.0001), successful intraoperative cholangiography (93% versus 73%; P < 0.0001), and exploration of the common bile duct (15% versus 5% of patients; P = 0.0005). The number of cholecystectomies performed by surgeons-in-training decreased from 65% to 40%, individual treatment costs were reduced by 62% and overall hospital costs were reduced by 53%. Complications fell from 12% to 7% (P = 0.07), with the only major bile duct injury occurring in 1989. There were three deaths in 1989 and two deaths in 1993. All deaths followed open surgery. CONCLUSIONS: Laparoscopic cholecystectomy is associated with improved patient outcomes and, despite the increased workload, significant savings for hospitals.

Cholecystectomy↗
PubMed1994

Evaluation of 2% sodium fluoride iontophoresis as an alternative to lining in Class I cavity preparations--an in vivo study.

The study carried out on 110 permanent teeth in 44 randomly selected patients with age ranging from 8-14 years, to evaluate the efficacy of 2% sodium fluoride iontophoresis as an alternative to cavity lining in Class I preparations. 65 teeth were included in the experimental group (2% sodium fluoride iontophoresis) and 4 teeth in the control group (Zinc phosphate linings). Sensitivity gradings were done on a subjective discomfort scale. From the results, it was found that after cavity preparation, all the teeth (100%) were sensitive to air blast, water jet and probing in varying severity. But after iontophoresis and amalgam restoration the sensitivity reduced to 4.6%. Six months and nine months follow up revealed that all the teeth were vital and asymptomatic.

Adolescent↗
PubMed1993

Response to antituberculous chemotherapy after splenectomy.

A case of a 17-year-old Indian male with disseminated tuberculosis is reported. While on chemotherapy, he was detected to have splenic abscesses. The patient remained unresponsive to antituberculous drugs until a splenectomy was performed.

Abscess↗
PubMed1993

Handedness in mental handicap: investigation into populations of Down's syndrome, epilepsy and autism.

The handedness in three randomly sampled groups of people with learning disabilities consisting of patients with Down's syndrome, epilepsy, and autism were studied using a validated instrument. All subjects were controlled for neurological and other medical disorders. A statistically significant increase in left-handedness and ambiguous handedness compared with the general population was found in all groups. There was no significant difference in the rate of left-handedness between the three groups.

Adult↗
PubMed1992

Methyl parathion-induced sperm shape abnormalities in mouse.

Metacid 50, the commercial grade of methyl parathion (O,O-dimethyl-O-4-nitrophenyl phosphorothionate), a commonly used organophosphorus insecticide, was tested for its genotoxicity in Swiss albino mice using the sperm abnormality assay. Sperms of albino mice were examined at two time intervals, 1 week and 5 weeks after a single acute oral treatment with the pesticide at four dose levels, viz., 75.0, 37.5, 18.75 and 9.375 mg/kg body weight corresponding to 1/2 LD50, 1/4 LD50, 1/8 LD50 and 1/16 LD50 values respectively. A dose-related statistically significant increase in the percentage of abnormal sperm observed indicates the genotoxic potency of methyl parathion.

Animals↗
PubMed1990

In vivo genotoxic effects in mice of Metacid 50, an organophosphorus insecticide.

The genotoxic effect of methyl parathion, an organophosphorus insecticide commercially available as Metacid 50, was studied in Swiss albino mice using bone marrow and peripheral blood micronucleus tests. Single acute oral doses of the insecticide at concentrations of 75.0, 37.5, 18.75 and 9.375 mg/kg body weight, equivalent to 1/2 LD50, 1/4 LD50, 1/8 LD50 and 1/16 LD50, administered to female mice, elicited positive responses in bone marrow and peripheral blood micronuclei tests. Statistically significant increases in the frequency of micronuclei were observed at higher doses in both the tests performed. The data obtained for our experiments suggest that methyl parathion is a potent mutagen and so it is also likely to have a genotoxic effect in humans.

Animals↗
PubMed1977

The use of equilin as an internal standard to quantitate estriol in pregnancy urine.

The assay of pregnancy urine estriol by gas chromatography is most often carried out by adding cholesterol as an internal standard at the end of the extraction procedure. The reason for this is that cholesterol does not contain a phenolic ring, and would be lost during the extraction procedure for estriol. This does not allow for corrections of recovery loss, which would be the case if the internal standard was a phenolic steroid. This paper describes the utilization of equilin (delta 1,3,5,7-estratetraen-3-01-17-one) as the internal standard. The sample is hydrolyzed to remove sulfate and glucuronide groups and then the equilin is added. If equilin is added before hydrolysis, variable destruction takes place. Derivative studies indicate that room temperature silylation can be used with bis (trimethylsilyl)-trifluoroacetamide/trichlorosilane/trimethylsilylimidazole, 3:3:2 by weight. Results on control material containing a low, critical pregnancy concentration of estriol were as follows--listed value 5.0 mg/1, found 5.3 mg/1, co-efficient of variation %, 8.9% for 17 runs on different days.

17-Ketosteroids↗