Search PubMed⌕ Search

Biomedical subjects

D Mak

Publications and source records attributed to D Mak.

At least 19 recordsLinked to original sources
PubMed2004

Outcomes of myringoplasty in Australian Aboriginal children and factors associated with success: a prospective case series.

The objective of this study was to assess the outcomes of myringoplasties in Aboriginal children and to identify factors associated with a successful outcome with the use of prospective case series from primary health care clinics and hospitals in four rural and remote regions of Western Australia. All 58 Aboriginal children, aged 5-15 years, who underwent 78 myringoplasties between 1 January 2000 and 30 June 2001 were included in the study. Complete postoperative (post-op) follow-up was achieved following 78% of myringoplasties. The main outcome measures were (a) success, i.e. an intact tympanic membrane and normal hearing six or more months post-op in the operated ear, (b) closure of the perforation, (c) Post-op hearing improvement. Forty-nine per cent of myringoplasties were successful, 72% resulted in closure or reduction in the size of the perforation and 51% resulted in hearing improvement. After controlling for age, sex, clustering and number of previous myringoplasties, no association was observed between success or hearing improvement and perforation size, or the presence of serous aural discharge at the time of surgery. Myringoplasty resulted in hearing improvement and/or perforation closure in a significant proportion of children. Thus, primary school-aged Aboriginal children in whom conservative management of chronic suppurative otitis media has been unsuccessful should have access to myringoplasty because of the positive impact on their socialization, language and learning that results from improved hearing.

Acoustic Impedance Tests↗
PubMed2001

John Flynn Scholarship students: case studies of useful contributions to remote health care.

In 1997, the John Flynn Scholarship (JFS) program was launched as an initiative to increase recruitment of doctors to rural areas. These scholarships enable undergraduate medical students to spend 2 weeks each year for 4 years at the same rural location. Given the magnitude of Australia's unmet rural health needs, we asked whether the experience could be enhanced by ensuring the students undertook meaningful work that was useful for the community. This paper describes, using case studies, some of the activities in which four JFS students have been involved and the positive contributions that they have made to rural health. The case studies indicate that pre-clinical students can be valuable members of the rural health workforce. We hope that if JFS students are given the opportunity to work as responsible health professionals they will have a better learning experience and will be more likely to return to the bush as doctors.

Adult↗
PubMed2000

Middle-ear disease in remote Aboriginal Australia: a field assessment of surgical outcomes.

Chronic middle-ear disease is highly prevalent among Australian Aboriginal people, and many undergo surgical treatment. However, the outcomes of surgery in this group have not been fully evaluated. This is a descriptive study of operations for middle-ear disease (excluding grommets) on Aboriginal patients in Kimberley hospitals between 1 October 1986 and 31 December 1995. Logistic regression was used to model predictors of surgical outcome. Success was defined by an intact tympanic membrane and air-bone gap of < or = 25 dB at review at, or later than, six months post-operation. A success rate of 53 per cent was observed; increasing age was the only variable predictive of success. Successful outcomes were more likely in adults and children aged > 10 years, however, this does not take into account the necessity of hearing for language acquisition and learning. Dedicated resources must be allocated for post-operative follow-up of Aboriginal patients so that much-needed, rigorous evaluations of ENT surgery can be conducted.

Adolescent↗
PubMed1998

Cystic fibrosis transmembrane conductance regulator-associated ATP release is controlled by a chloride sensor.

The cystic fibrosis transmembrane conductance regulator (CFTR) is a chloride channel that is defective in cystic fibrosis, and has also been closely associated with ATP permeability in cells. Using a Xenopus oocyte cRNA expression system, we have evaluated the molecular mechanisms that control CFTR-modulated ATP release. CFTR-modulated ATP release was dependent on both cAMP activation and a gradient change in the extracellular chloride concentration. Activation of ATP release occurred within a narrow concentration range of external Cl- that was similar to that reported in airway surface fluid. Mutagenesis of CFTR demonstrated that Cl- conductance and ATP release regulatory properties could be dissociated to different regions of the CFTR protein. Despite the lack of a need for Cl- conductance through CFTR to modulate ATP release, alterations in channel pore residues R347 and R334 caused changes in the relative ability of different halides to activate ATP efflux (wtCFTR, Cl >> Br; R347P, Cl >> Br; R347E, Br >> Cl; R334W, Cl = Br). We hypothesize that residues R347 and R334 may contribute a Cl- binding site within the CFTR channel pore that is necessary for activation of ATP efflux in response to increases of extracellular Cl-. In summary, these findings suggest a novel chloride sensor mechanism by which CFTR is capable of responding to changes in the extracellular chloride concentration by modulating the activity of an unidentified ATP efflux pathway. This pathway may play an important role in maintaining fluid and electrolyte balance in the airway through purinergic regulation of epithelial cells. Insight into these molecular mechanisms enhances our understanding of pathogenesis in the cystic fibrosis lung.

1-Methyl-3-isobutylxanthine↗
PubMed1998

An outbreak of non-sexually transmitted gonococcal conjunctivitis in Central Australia and the Kimberley region.

From 13 February to 27 June 1997, 447 cases of gonococcal conjunctivitis were identified by Communicable Disease and Public Health Centres and Community Clinics in the Northern Territory, Western Australia and South Australia. The outbreak involved Aboriginal communities predominantly in Central Australia and the Kimberley region in Western Australia. This was the first outbreak recorded in the Kimberley region. It is not yet known whether the Kimberley cases were part of the larger Central Australian outbreak or whether they represented a separate and unrelated outbreak. Environmental factors associated with this outbreak were similar to those seen in previous outbreaks. Control measures were based on early recognition and treatment of index cases and identifying and treating contacts. Until sexually transmitted Neisseria gonorrhoeae is controlled in communities gonococcal conjunctivitis is likely to appear again. The role of oropharyngeal carriage of N. gonorrhoeae needs to be evaluated further.

Adolescent↗
PubMed1997

Effects and sustainability of a cervical screening program in remote Aboriginal Australia.

We assessed the effects of an organised cervical screening program, using a population-based cervical cytology register, for Aboriginal women in the Fitzroy Valley, a remote part of the Kimberley region of Western Australia. Comparison of age-specific screening rates in the area during 1987-88, 1990-92 and 1993-94 showed that establishing the program in late 1989 was accompanied by dramatic increases in cervical screening rates, ranging from two- to over fourfold, with the largest increases in women aged 50 years and over. Following the departure of the coordinator in early 1993, screening rates decreased to between 76 per cent and 29 per cent of their 1990-92 levels, with the largest decreases occurring in the 40-49 and 60-69 years age groups. Rates were still above 1987-88 levels for most age groups. Of 545 women screened during 1991-92, 65 per cent had undergone a second Pap smear within the follow-up period of two to four years. Among women recommended for a repeat smear in two years, the probability of having a second smear was negatively associated with age (log-rank statistic = 35.58, 4 df, P < 0.0001). Follow-up of smears recommended for repeat in 12 months or earlier was less adequate in 1993-94 (46 per cent) than in 1991-92 (75 per cent). The program was successful in recruiting a large proportion of eligible women within a relatively short time, but coverage, especially of older women, was not sustained after a decline in the functioning of the recall system owing to staffing and organisational changes.

Adolescent↗
PubMed1994

Phase II trial of procarbazine, vincristine and lomustine (POC) chemotherapy in metastatic cutaneous malignant melanoma.

40 patients with symptomatic metastatic melanoma were treated with procarbazine, vincristine and lomustine (POC). 4 patients had received chemotherapy previously. Responses were seen in 8 patients (20%), 4 of whom had a complete remission. All responding patients had some tumour shrinkage after one cycle. The median duration of response was 27 weeks, with 2 patients remaining in complete remission at 6 and 6.5 years. The median survival for the whole group was 22 weeks, whilst that of the responding patients was 35 weeks. Using conventional anti-emetics, the principal toxicities were nausea and vomiting, severe in 15% of cycles. Other nonhaematological toxicity was uncommon. Neutropenia (WHO grade 3 or 4) occurred in 11% of cycles and thrombocytopenia in 8%. The response rate of metastatic melanoma to POC chemotherapy was similar to other cytotoxic regimens though toxicity, other than nausea and vomiting, was minimal. The rapid response allows patients with unresponsive disease to be identified early, avoiding continuing toxicity.

Adult↗
PubMed1993

Patient assessment of a combined medical and nursing preparation to cytotoxic chemotherapy.

At Auckland hospital there is a combined medical and nursing preparation for patients receiving cytotoxic chemotherapy. The aim of the current study was to assess whether patients felt that this combined approach had prepared them adequately for chemotherapy. Patients were asked to complete three questionnaires anonymously at different times in their treatment programme: immediately prior to chemotherapy, after three cycles of chemotherapy and 2 months after completion of chemotherapy. A high level of satisfaction with the programme was demonstrated: 68% of patients thought the orientation programme had prepared them "very well", 32% "adequately" and none "poorly" for their chemotherapy. Separate interviews with medical and nursing staff were thought a "good idea" by 86% of patients and only 1 of 100 medical and 100 nursing interviews was assessed as "not worthwhile". This study suggests that a combined medical and nursing preparation is a worthwhile practice in preparing patients for cytotoxic chemotherapy.

Adult↗
PubMed1992

Ondansetron reduces chemotherapy induced nausea and vomiting refractory to standard antiemetics.

Ondansetron, a selective 5HT3 (serotonin) antagonist, was used in patients refractory to standard antiemetics. Seventy-five patients receiving chemotherapy without cisplatin were given ondansetron 4 mg IV and 4 mg orally immediately prior to chemotherapy, then 8 mg orally after six and 12 hours, followed by 8 mg orally eight hourly during days 2-5. Complete control of vomiting occurred in 52 patients (69%) on the first day and 45 patients (60%) on days 2-5. Sixty patients (80%) preferred ondansetron to their previous antiemetics. The efficacy of ondansetron was maintained over multiple chemotherapy cycles. Ondansetron was also given to 16 patients receiving cisplatin chemotherapy. They received 8 mg IV immediately prior to chemotherapy followed by an infusion of 1 mg/hr for 8 hr, with 8 mg orally at the end of the infusion and then 8 mg orally eight hourly during days 2-6. Some control of vomiting (less than = 5 vomits) was achieved in eight patients (50%) on the first day and in 14 patients (87%) on subsequent days. Eight patients (50%) preferred ondansetron to their previous antiemetics. Adverse events with ondansetron were frequent but mild, with constipation and headache being most common. Ondansetron is highly effective in patients refractory to standard antiemetics, especially after noncisplatin chemotherapy.

Adult↗
PubMed1991

Reduction of carboplatin induced emesis by ondansetron.

Ondansetron is a selective 5-HT3 antagonist with significant antiemetic properties in patients receiving cytotoxic chemotherapy. Patients who had suffered severe vomiting on carboplatin alone (23 patients with ovarian carcinoma) or in combination (two patients with testicular cancer) despite intensive antiemetic regimens were treated with ondansetron, given as 8 mg immediately prior to carboplatin followed by 8 mg orally, 8 hourly for 5 days. Twenty-five patients received 58 courses of ondansetron. In the first 24 h after the first course of chemotherapy with ondansetron, 17 patients (68%) experienced no vomiting, five patients (20%) had almost complete control and the other three patients had partial control. During the subsequent 4 days slightly lesser control was achieved. Nausea was similarly controlled in most patients. Twenty-two patients stated a preference for ondansetron with future chemotherapy. Fourteen patients received additional chemotherapy with ondansetron and in only three patients did the efficacy of therapy lessen. Toxicity was mild and transient with headache and constipation predominant. No extrapyramidal reaction was seen. Sedation was absent. Ondansetron is highly effective in refractory vomiting associated with carboplatin chemotherapy. It may be particularly beneficial when an extrapyramidal reaction has occurred on previous antiemetics and when sedation is unacceptable.

Antiemetics↗
PubMed1984

[Evaluation of 6 years of CO2 laser microsurgery in laryngology].

Laryngeal microsurgery has been performed using a CO2 laser since 1978. It is essential to conduct a strict phoniatric pre-operative examination and to ensure correct anesthesia. Results after 735 operations underline the advantages of this technique for the treatment of benign laryngeal lesions (diffuse papillomatosis, sessile polyps, granuloma), in phonosurgery (nodules, bundle edema, corditis) and in the repermeabilization of the laryngeal network (paralysis, stenosis, laryngeal edema).

Carbon Dioxide↗
PubMed1981

[Pharmacoclinical competition between the benzodiazepines. Demonstration with diazepam and flunitrazepam in man].

While using a new benzodiazepines flunitrazepam by the intravenous route in ordinary anethesia a competitive action with another benzodiazepine which is being used for the last 15 years, namely diazepam, was demonstrated for the first time in man. This study on 170 patients operated for ear, nose and throat conditions demonstrated this phenomenon, confirmed it and it was possible to reproduce the effect. The interaction is mainly characterized by: - A reduction of the effects of flunitrazepam (less profound sleep, even wakefulness with a waking patient who could talk and could react to pain). This effect was obtained with injection of a normal clinical dose of diazepam. - There was a blocking action or a reduction in the pharmacological action normally expected of flunitrazepam by the previous administration of a clinical dose of diazepam, when given by the intravenous, intramuscular or oral routes. This suggests that there are common receptor sites for these two benzodiazepines at the cerebral level and this would explain this apparently paradoxical action. Even though flunitrazepam has a greater affinity for these receptor sites this molecule seems to be displaced, according to the law of mass action, by diazepam when used at a high dose. This interaction shown for these two benzodiazepines is also seen in other derivatives of the same chemicals series. This is important in therapeutics with the increasing use of these products in general medicine, and anesthetics and neuropsychiatry where they are quite often used in association.

Adolescent↗
PubMed1976

[Trials of controlled hypotension with sodium nitroprusside in ORL surgery. Resistance and tachyphylaxis].

Sodium nitropusside has been used to lower blood pressure during surgical operations on the ear, nose and throat when an operative field without bleeding was desired, e.g. surgery of the inner ear under microscope in particular. In our experience, with the preparation used, sodium nitropusside proved to be a powerful hypotensive agent, the effect of which comes on early but it is difficult to use owing to frequent tachyphylaxis, the possible causes of which are considered. No undesirable side-effects were noted on the main functions. From this limited personal experience, the efficacy of this technique of per-operative hypotension did not appear greater in the surgical field under consideration to those of the anaesthetic techniques used commonly, e.g. neuroleptanalgesia under artificial ventilation, which proved sufficient for reduction in operative bleeding and which had already caused the authors to abandon, some time ago, the use of hypotensive ganglioplegic drugs.

Adolescent↗