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Biomedical subjects

M Mars

Publications and source records attributed to M Mars.

At least 55 records · Page 3Linked to original sources
PubMed1996

Management of cleft lip and palate.

The complex nature of treatment for CL/P, a condition that requires a large multidisciplinary team treating patients from birth to maturity, has been outlined. Subjecting centres' outcomes to audit should precede heeding the current siren calls for paediatricians to refer children exclusively to a particular surgical speciality. A growing body of evidence has shown a close correlation between quality of outcome and the availability of high volume centralised care by dedicated teams, as has been proved and accepted for years in other fields such as surgery in infancy, childhood malignancies, and cystic fibrosis.

Adolescent↗
PubMed1996

The Goslon yardstick applied to a consecutive series of patients with unilateral clefts of the lip and palate.

First described in 1987, the Goslon yardstick has been used since as a reliable and reproducible means of measuring dental arch relationships and, therefore, the quality of facial growth. The dental study models of a group of 32 consecutively treated patients with unilateral clefts of lip and palate, from the Frenchay Hospital, Bristol, U.K., were analyzed using the Goslon yardstick. More than 50% of the sample were in the unfavorable Goslon groups IV and V. Because of these results, we at Frenchay Hospital now base our related surgical procedures on the early vomerine closure of the anterior hard palate without nasal or alveolar repair at 3 months, followed by primary hard and soft palate closure at 6 months.

Age Factors↗
PubMed1996

Students' perceptions of a multimedia computer-aided instruction resource in histology.

OBJECTIVE: To develop an interactive multimedia-based computer-aided instruction (CAI) programme, to determine its educational worth and efficacy in a multicultural academic environment and to evaluate its usage by students with differing levels of computer literacy. DESIGN: A prospective descriptive study evaluating pre- and post-module testing, student usage tracking and a questionnaire survey. SETTING: University of Natal Medical School. PARTICIPANTS: Thirty-four volunteers from the class of 125 second-year M.B. Ch.B. students who participated in the CAI study; 13 of these were not computer-literate. INTERVENTION: The study group used the CAI module for 2 weeks as part of the course. MAIN OUTCOME MEASURES: Post-test scoring and evaluation of questionnaire responses. RESULTS: Results of pre- and post-tests show that CAI users' scores were slightly lower on pre-testing (22.1% v. 23.2%), while their post-test scores were higher (65.6% v. 60.7%). Lack of computer literacy did not restrict or hinder students in their use of the programme. Responses to a questionnaire completed by all CAI users indicate consensus that the programme helped the students to learn (94%), that it provided important basic knowledge (88%) and that it was a helpful learning experience (88%). All but 1 student wished to have more programmes like this available in histology. CONCLUSIONS: The CAI programme reduced the time spent by students in the histology microscopy laboratory and did not negatively affect their marks in post-course evaluation. The concept of multimedia-based CAI in medical education was positively received by the students who participated.

Computer-Assisted Instruction↗
PubMed1995

Morphological aspects of microarterial anastomoses: a comparison of nylon with polydioxanone.

The morphological appearance of longitudinally sectioned rat femoral arteries was determined in intact arteries and from 3 to 435 days after vessel division and anastomosis with either 9/0 gauge nylon or polydioxanone (PDS) in 26 animals. The purpose of the study was to establish the mechanisms and compare the quality of healing after microarterial anastomosis and to determine whether PDS was degraded before sufficient anastomotic healing had taken place. The results revealed that there was no difference in the process of healing or quality of anastomosis with either suture material. From 3 to 21 days post anastomosis, there was a progressive separation of the ends of vessels within the developing scar. Anastomotic patency was established and maintained at first by an adventitial overgrowth of fibroblasts and undifferentiated adventitial cells and later by the growth of a smooth myocyte scar that stretched between the cut ends of the vessel and over the intima in the form of elongated circumferential plaques. The vessel was morphologically healed by the 21st day. The sutures served little or no purpose in maintaining anastomotic integrity after the 5th day, being situated in the scar forming between the separating vessel ends. PDS was present within the vessel wall up to 120 days post anastomosis and was certainly intact at the time of morphological healing, suggesting that this material is safe as a microvascular suture.

Anastomosis, Surgical↗
PubMed1994

Traumatic arteriovenous fistula: experience with 202 patients.

Experience with the management of 202 patients with 210 traumatic arteriovenous fistulas is reported. Penetrating trauma accounted for 98 per cent of injuries caused mainly by stabs (63 per cent) and missile wounds (26 per cent). Seven of 15 patients with shotgun wounds had multiple lesions. Over half of all fistulas occurred in the cervico-mediastinal vessels; abdominal and thoracic vessels were infrequently involved. The upper limbs were involved in 22 per cent and the lower limbs in 20 per cent. Some 133 patients were diagnosed and treated within 1 week of injury; 69 presented 1 week to 12 years later. Machinery murmur was noted in 61 per cent of the early presenters, but was an almost universal finding in those presenting late. Only three patients had cardiac failure and all had underlying cardiomyopathy. Active overt haemorrhage was not common. Arterial continuity was restored in 80 per cent of cases, usually by autogenous reconstruction. Venous injury was usually treated by ligation or lateral suture. Patients treated within 1 week of injury had a lower rate of perioperative mortality and morbidity than those treated late, due mainly to technical difficulties in controlling the vessels caused by fibrosis and massive venous dilatation. If a policy of selective exploration of penetrating trauma is to be followed, careful assessment for arteriovenous fistula must be made and the patient evaluated at regular intervals for several months. Shotgun injuries require routine angiography at the time of presentation. The earlier treatment is instituted, the better the results.

Abdominal Injuries↗
PubMed1994

Failure of pulse oximetry in the assessment of raised limb intracompartmental pressure.

Pulse oximetry has been proposed as an aid to monitoring raised intracompartmental pressures (ICPs). ICP and percentage haemoglobin oxygen saturation in the affected limb were studied in 10 consecutive patients with raised ICP. Compartment pressures ranged from 28 to 64 mmHg (mean 40.9 mmHg). In two patients with absent pulses, pulse oximetry failed to detect pulsatile flow and recorded 0 per cent saturation. The remaining eight patients, including four with absent peripheral pulses, all had percentage haemoglobin saturations within 2 per cent of the opposite normal limb. Arterial haemoglobin desaturation was not associated with raised ICP. The presence of an oximeter signal and a normal reading does not necessarily imply adequacy of tissue perfusion. Pulse oximetry does not appear to be a reliable aid in the diagnosis or monitoring of impaired perfusion due to raised ICP.

Adolescent↗
PubMed1994

The effect of post-operative bleeding on compartment pressure.

The effect of post-operative haemorrhage on intra-compartmental pressure has been studied in a primate model. The common practice of closing a wound and applying a compression bandage before deflating the tourniquet is shown to raise intra-compartmental pressure. Subsequent tourniquet release causes a further rise in pressure. Post-operative intra-compartmental pressure remains significantly higher during the first 3 hours of reperfusion in limbs bandaged prior to tourniquet release than in limbs in which the tourniquet is released and haemostasis gained before compression bandaging is applied.

Animals↗
PubMed1994

Can pulse oximetry detect raised intracompartmental pressure?

Pulse oximetry has been advocated as a simple noninvasive investigation of vascular compromise. Its usefulness in aiding diagnosis of microvascular compromise in a developing compartment syndrome is questioned. This study investigates the reproducibility of pulse oximetry and the effect on arterial haemoglobin saturation of raising limb intracompartmental pressure by compression bandaging. In 32 out of 50 normal subjects there was a difference in percentage saturation between right and left arms, with a 2% difference in 6 people (12%). Percentage saturation fell significantly at average bandage pressures of 80 mmHg (P < 0.0001) and 60 mmHg (P < 0.001). At clinically relevant pressures, the test had a sensitivity of 40.4%. With a greater than 50% risk of a false-negative result, pulse oximetry is not an appropriate additional investigation in the detection of raised intracompartmental pressure.

Adult↗
PubMed1993

Sri Lankan cleft lip and palate study model analysis: clefts of the secondary palate.

The study models of a group of adult Sri Lankan patients with clefts of the secondary palate were investigated. Tooth-size and arch-dimension comparisons were made with a comparable control group. Significant differences were found between the cleft and control groups in tooth sizes, chord lengths, and arch widths. The cleft group dimensions were generally smaller than those of the control group. Overjets were larger in the cleft group.

Adult↗
PubMed1993

Timing of hard palate closure and dental arch relationships in unilateral cleft lip and palate patients: a mixed-longitudinal study.

In a mixed longitudinal study, dental arch relationships of 88 consecutive UCLP patients treated at the Nijmegen Cleft Palate Centre were evaluated using the Goslon Yardstick. On the basis of timing of hard palate closure, the patients were divided into four groups. Mean age of hard palate closure the patients were divided into four groups. Mean age of hard palate closure in group A (n = 18) was 1.5 years, in group B (n = 26) 4.6 years and in group C (n = 18) 9.4 years. In group D (n = 26, no patient older than 10 years) the hard palate was still open. Four stages of dental development were distinguished; deciduous dentition, early mixed dentition, late mixed dentition and permanent dentition. Reproducibility of scoring with the Goslon Yardstick was good for all stages of dental development. No differences in dental arch relationships were found between the four groups. In 86% of the cases, the dental arch relationships of UCLP patients treated in Nijmegen were acceptable. Pharyngeal flap surgery had minor unfavorable effects on dental arch relationships.

Adolescent↗
PubMed1993

The potential benefit of pre-operative assessment of amputation wound healing potential in peripheral vascular disease.

Choosing the most distal amputation level that will heal is difficult in patients with peripheral vascular disease. From 1984 to 1988, 965 patients underwent 1,563 amputations for lower limb peripheral vascular disease at King Edward VIII Hospital, Durban. The primary amputation revision rate was 51% with a mortality rate of 23.1%. Random pre-operative assessment of amputation wound healing potential using a transcutaneous oxygen pressure index was investigated over the 4-year period, 1987-1990. This was responsible for a reduction in the amputation revision rate to 8.2% in patients tested.

Amputation, Surgical↗
PubMed1992

Serial morphological changes in primate skeletal myofibres after 3 hours of ischaemia and 24 hours of reperfusion.

The sequential morphological changes occurring in skeletal myofibres after 3 hours' ischaemia and from 3 hours to 24 hours of reperfusion in vervet monkeys are described. Eight vervet monkeys were studied under general anaesthesia. A hind limb was exsanguinated and a tourniquet applied for 3 hours. Open muscle biopsy specimens were obtained from the tibialis anterior muscle before tourniquet application, just before tourniquet release and 3, 6, 12, 18 and 24 hours after tourniquet deflation. All specimens were prepared for transmission electron microscopy. After 3 hours of ischaemia and increasing periods of reperfusion, a small number of fibres showed progressive pathomorphological changes that eventually resulted in myofibre death. After initial glycogen loss and later intermyofibrillar oedema, the majority of myofibres returned to normal, while a group of fibres remained oedematous. The progressive morphological characteristics of reversibly injured myofibres undergoing repair and irreversible injured cells undergoing necrosis are described.

Animals↗
PubMed1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 2. Craniofacial form and soft tissue profile.

The craniofacial morphology and the soft tissue profile were evaluated in this part of the intercenter study of the European Cleft Lip and Palate Research Group. The sample was comprised of cephalometric x-rays of the full cohort of 151 cases from the six European cleft palate centers. The facial morphology in complete unilateral cleft lip and palate patients was evaluated by means of roentgen cephalometry. Approximately 25 consecutive cases from each of six European cleft palate centers were compared. Only one center showed notable and consistent differences from the others. A contributing factor for these differences may be an inconsistent treatment regimen with many surgeons involved. Analysis of the soft tissue profile between the centers showed more pronounced differences than analysis of the skeletal profile. The treatment outcome in centers with more complex or expensive programs was no better than those centers using simpler management approaches.

Analysis of Variance↗
PubMed1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 3. Dental arch relationships.

One hundred and forty-nine dental casts of subjects with complete unilateral clefts of the lip and palate from six European cleft palate centers were assessed by means of the Goslon Yardstick. The Yardstick proved capable of discriminating between the quality of the dental arch relationships between the six centers. Two centers showed especially poor results. Three centers obtained satisfactory results although differing surgical techniques were used in these centers. One of the centers showing satisfactory dental arch relationships employed a more complex and expensive treatment program than the other two centers, which both used simpler centralized treatment regimens.

Analysis of Variance↗
PubMed1992

A six-center international study of treatment outcome in patients with clefts of the lip and palate: Part 5. General discussion and conclusions.

Part 5 is the final part of a series of five articles reporting on an international, multicenter clinical audit of treatment outcome for complete UCLP. A number of recommendations for the methodology of future studies is made especially with respect to entry criteria, sample size, assumptions of homogeneity, and the reproducibility and validity of outcome measures. The findings of the present study regarding clinical procedures are presented tentatively, and improvement and extension of the methodology are required. It appears, however, that acceptable results can be achieved by different programs and ultimately clinical choices may be based on factors such as complexity, costs, and demands of treatment. Standardization, centralization, and the participation of high volume operators were associated with good outcomes, and nonstandardization and the participation of low volume operators with poor outcomes. Therapeutic factors associated with good outcomes were the employment of a vomer flap to close the anterior palate, and poor outcomes with primary bone grafting and with active presurgical orthopedics.

Bone Transplantation↗
PubMed1992

The Sri Lanka cleft lip and palate project--the medical illustrator's contribution.

Since 1984, a series of visits to the island of Sri Lanka by an assessment team, and a team of surgeons and anaesthetists, has amassed a huge dataset on unoperated cleft lip and palates and carried out surgery on over 600 patients. In addition, the training of local Sri Lankan professionals was undertaken. The two most recent trips in 1990 are described with reference to the photographic and audiovisual records collected.

Adult↗