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Biomedical subjects

D Sanderson

Publications and source records attributed to D Sanderson.

At least 19 recordsLinked to original sources
PubMed2002

Second-generation microstimulator.

The first-generation injectable microstimulator was glass encased with an external tantalum capacitor electrode. This second-generation device uses a hermetically sealed ceramic case with platinum electrodes. Zener diodes protect the electronics from defibrillation shocks and from electrostatic discharge. The capacitor is sealed inside the case so that it cannot be inadvertently damaged by surgical instruments. This microstimulator, referred to as BION, is the main component of a 255-channel wireless stimulating system. BION devices have been implanted in rats for periods of up to 5 months. Results show benign tissue reactions resulting in identical encapsulation around BION and controls. Stimulation threshold levels did not change significantly over time and ranged between 0.81 to 1.35 mA for all the animals at a 60 micros pulse width. All of the tests performed to date indicate that the BION is safe and effective for long-term human implant. We have elected to develop BION applications by seeking collaboration with the research community through our BION Technology Partnership.

Animals↗
PubMed2001

Physiotherapy following cardiac surgery: is it necessary during the intubation period?

This randomised controlled clinical trial investigated whether physiotherapy during the period of mechanical ventilation following cardiac surgery influenced subject outcomes. Two hundred and thirty-six subjects admitted to the intensive care unit (ICU) following elective or semi-urgent cardiac surgery were randomised to either a treatment group, which received physiotherapy during the intubated phase, or a control group where physiotherapy was commenced only once the subject was extubated. No significant differences between the two groups were detected for length of intubation period, length of ICU stay, length of hospital stay, maximal daily incentive spirometry values or the incidence of post-operative pulmonary complications. For individuals following routine uncomplicated cardiac surgery, the provision of physiotherapy interventions during the post-operative intubation period does not improve outcomes.

Adolescent↗
PubMed1997

Prenatal diagnosis for inborn errors of metabolism and haemoglobinopathies: the Montreal Children's Hospital experience.

We reviewed all referrals for prenatal diagnosis for inborn errors of metabolism and haemoglobinopathies performed at the Montreal Children's Hospital Prenatal Diagnosis Centre/McGill University during the period 1990-1995; 92 procedures were performed for these indications (less than 1 per cent of all referrals for prenatal diagnosis). All prenatal diagnoses for haemoglobinopathies (n = 55) were exclusively DNA-based. The three most frequent referrals were for beta-thalassaemia, sickle cell anaemia, and Tay-Sachs disease, accounting for 68 per cent of cases; the other indications were predominantly for untreatable inborn errors of metabolism. Our unit maintains population-based carrier screening programmes in high schools for beta-thalassaemia and Tay-Sachs diseases. Carriers detected in these programmes accounted for the majority of referrals for these two conditions. This study indicates that carrier testing and screening for sickle cell anaemia may be also welcomed by at-risk groups in Quebec.

Female↗
PubMed1997

Carcinoma of the lung in three brothers and two sisters.

Documentation of familial aggregation of five siblings with lung cancer is presented. Lung cancer was not observed in their parents nor among their children, which is consistent with the hypothesis of recessive inheritance, although strong environmental factors such as tobacco smoking may contribute to the development of lung cancer in such families.

Adult↗
PubMed1996

Speech assessment of patients using three types of indwelling tracheo-oesophageal voice prostheses.

A multidisciplinary prospective study compared speech acceptability between three types of indwelling tracheo-oesophageal voice prostheses. Twenty male laryngectomees took part over five years, using 42 prostheses. Speech was assessed on a discrete scale by trained and untrained personnel. The majority scored in the mid-range for each assessor. The kappa coefficient was used to test similarity between assessors, and for all pairings agreement was significant (p < 0.05). The speech and language therapist tended to give higher scores and the patient lower. A relationship was found between patients' ages categorized by decade and the surgeon's score alone. This relationship held for Groningen high resistance and Provox prostheses individually too (p < 0.05). The untrained assessed similarly to the professionals--humans are all voice listeners. The analysis suggests surgeons find tracheo-oesophageal speech in older patients better than in younger ones; or make more allowances for the elderly. There was a trend for Provox prostheses to produce the best scores.

Age Factors↗
PubMed1996

In vivo measurements of indwelling tracheo-oesophageal prostheses in alaryngeal speech.

Over the last 5 years, detailed air pressure, flow and voice measurements have been made on indwelling tracheo-oesophageal speaking valves whilst inserted in patients, using specially designed apparatus. This study was set up to investigate the relationship between speech and in vivo parameters. In vivo pressure measurements were generally lower for Groningen low resistance than Groningen high resistance, while flow and voice measurements were higher. A plot of opening pressure against pressure at maximum flow for all valves suggested a straight line relationship. A graph of maximum voice against composite parameter score for all valves showed a cluster of points between the composite score of 0-15. The advances in knowledge about these valves should be of use in the design of improved valves.

Aged↗
PubMed1995

New method for stem cell quantification: applications to the management of peripheral blood stem cell transplantation.

A dramatic increase in peripheral blood stem cells (PBSC) is observed after high-dose chemotherapy followed by haematopoietic growth factors. The degree of mobilisation of PBSC is quantified by the level of clonogenic cells detected by CFU assays (CFU-GM or CFU-GEMM) or CD34+ cell determination. Working under the hypothesis that, in peripheral blood, mononuclear cells in DNA synthesis (MCDS) are proliferating stem cells, we decided to detect these cells by flow cytometric measurement of their DNA content. The relations between the number of MCDS and well-known haematopoietic progenitor indicators such as CFU-GM or CD34+ cells were analysed. We studied the kinetics of recruitment of PBSC in cancer patients, treated with rmeHuG-CSF following VP-16 cytoxan chemotherapy, until the first day of leukapheresis. For the 31 patients studied the individual curves of peripheral MCDS and CFU-GM reconstitutions showed identical profiles and a good correlation was noted between the numbers of peripheral MCDS and CFU-GM (r = 0.73). In the leukapheresis product, the predictive value of MCDS was equivalent to CFU-GM for PBSC quantification (r = 0.70). In conclusion, MCDS analysis by flow cytometry provides reliable results and appears to be an alternative to CFU-GM assay or CD34+ cell determination for PBSC quantification.

Adult↗
PubMed1989

Taking cervical smears in departments of genitourinary medicine.

The smear taking practices of departments of genitourinary medicine were investigated by telephone inquiry. Departments seem to be broadly and equally divided into those where the smear is taken before the cervix is wiped or endocervical specimens are taken for microbiology, and those where the smear is taken afterwards. In the unit at Guy's Hospital we compared cervical smears taken in both of these sequences and concluded that, to diagnose more cases of premalignant cervical disease, smears should be taken before any other cervical samples.

Female↗
PubMed1983

Neuromuscular electrical stimulation for the head-injured patient.

Recent research has shown that electrical stimulation is effective in treatment programs designed to maintain or gain range of motion, to facilitate voluntary motor control, and to strengthen muscles weakened by disuse. All of these treatment goals are relevant to the head-injured patient who frequently demonstrates profound disuse atrophy, joint contractures with excessive muscle tone, and decreased voluntary motor capabilities. As the cognitive status of the head-injured patient improves, electrical stimulation can be incorporated into traditional treatment programs to enhance their effectiveness. This article discusses using neuromuscular electrical stimulation with programs aimed at managing contractures, reducing spasticity, and facilitating voluntary motion. The limitations of electrical stimulation in the head-injured patient population are addressed.

Adult↗
PubMed1982

Results of Mayo lung project: an interim report.

Screening for lung cancer by chest roentgenography and sputum cytology can be conducted by mail. Detection, localization, and treatment of early presymptomatic lesions are possible. The initial prevalence of lung cancer in men older than age 45 years who were heavy smokers was almost 1%. Rescreening at 4-monthly intervals detected 4.7 new cases of lung cancer per 1,000 subjects per year. Three times as many postsurgical stage I lesions were detected in the screened group as in the control group. Although survival seems to have been improved by screening, mortality from lung cancer is not yet significantly different in the 4-monthly surveillance and control groups. Longer follow-up is necessary for determination of the ultimate usefulness of screening.

Adenocarcinoma↗