PubMed Health⌕ Search

Biomedical subjects

R A Cooke

Publications and source records attributed to R A Cooke.

At least 19 recordsLinked to original sources
PubMed1992

Ciprofloxacin in the treatment of Mycobacterium fortuitum infection of the peroneal tendons. A case report.

In the case reported, M. fortuitum was sensitive in vitro to amikacin, erythromycin, tobramycin, and ciprofloxacin. Because the patient did not respond to long-term therapy with amikacin and erythromycin, an experimental antibiotic, ciprofloxacin, was tried. Only after extensive surgical debridement and 2 1/2 months of oral ciprofloxacin therapy was the infection eradicated and wound healing obtained. The authors conclude that a wound that has reopened, but remains indolent, exudes a clear, serous drainage and responds poorly to antibiotics should suggest a possible mycobacterial infection. Combination antibiotic therapy is recommended because of the high rate of relapse and development of resistance to drugs. Extensive surgical debridement of all infected tissue remains the primary treatment. The therapeutic value of ciprofloxacin and other newer antibiotics in the treatment of mycobacterial infection is promising.

Adult↗
PubMed1992

The role of echocardiography in the diagnosis and management of infective endocarditis.

The echocardiographic appearance in suspected endocarditis must always be interpreted in the context of the clinical findings. Thus although echocardiography may contribute to the early diagnosis of infective endocarditis, it should rarely be used as a screening test. It is highly sensitive for the detection of complications such as abscesses or valvular regurgitation and can estimate their severity. Although transthoracic imaging will allow a complete study in many cases, the transoesophageal approach is superior for the detection of abscesses and the assessment of prosthetic mitral valves. Patients with large vegetations, particularly on the mitral valve, are at increased risk of embolism but there is no convincing evidence to support prophylactic surgery in these cases.

Echocardiography↗
PubMed1991

Temporal change in diagnostic criteria as a cause of the increase of malignant melanoma over time is unlikely.

To assess whether the increase in malignant melanoma incidence could be due, at least in part, to changes in histological criteria of malignancy, pathologists in Australia, France, Italy, New Zealand, Norway, Sweden, the United Kingdom, the United States and the USSR reviewed diagnoses of 50 consecutive pigmented naevi (40 junctional and compound; 10 intradermal) and 20 consecutive malignant melanomas made in each participating centre around 1930, around 1955 and around 1980. Collaborating pathologists re-read the material, 2,665 cases in all, either from the original slide (82%) or from a recut block (17%), gave their diagnosis and indicated whether the lesion was benign (B), dubious benign (DB), dubious malignant (DM) or malignant (M). As the distribution of review diagnoses was much the same whether the original slide or one made from a recut block was read, the material was pooled. Overall, 2.8% of cases originally reported as B/DB were reviewed as DM/M, while 4.4% of the DM/M diagnoses were held to be B/DB. The shifts between categories were greatest around 1955 and least around 1980, suggesting increasing uniformity of interpretation. All available blocks were recut and sections sent to IARC for review: 1.7% (22) of 1293 B/DB diagnoses were considered to be DM/M and 3.3% (18) of 551 DM/M diagnoses were considered to have been B/DB. The consistently low frequency of shift in diagnostic category, whether the material was reviewed in the collaborating laboratories or by one pathologist at IARC, in a study designed to give maximum attention to those lesions--the junctional and compound naevi--in which a change in opinion as to malignancy would be most likely to arise, suggests that pathologists, irrespective of geographical location, are using common criteria. These findings argue against changes in histological interpretation as being responsible for more than a small portion of the continuous increase of some 3% to 8% per annum observed in malignant melanoma incidence. Other explanations, such as an increase in the frequency or potential for malignant transformation of precursor lesions, must be sought. The anatomical distribution of the malignant melanomas examined followed the usual site pattern by sex, and their thickness was observed to decrease over the period of the study in most centres.

Female↗
PubMed1990

Cellular localisation of tumour antigen (TA-4) in normal, dysplastic and neoplastic squamous epithelia of the upper aerodigestive tract.

We report the use of tumour antigen (TA-4) polyclonal antiserum to assess the level and pattern of TA-4 antigen expression in formalin-fixed paraffin-embedded tissue sections from 110 patients with a range of normal, dysplastic and malignant squamous epithelia from various sites in the upper aerodigestive tract. There was a high degree of TA-4 antigen expression in the superficial layers of normal squamous epithelium and in well-differentiated squamous cell cancers (SCC). TA-4 expression was consistently absent in dysplastic oral squamous epithelium and in poorly differentiated SCCs. The degree of cellular heterogeneity in moderately differentiated SCCs was such that morphologically identical squamous cancer cells could be distinguished on the basis of TA-4 expression. Immuno-electron microscopy localised TA-4 antigen to tonofibrils in both normal buccal (squamous) cells and in squamous cancer cells. Results of Western blotting confirmed the presence of a 48 kDa protein consistent with TA-4 antigen in both SCCs and in normal buccal mucosa. We conclude that TA-4 protein is a normal cellular component, that cellular TA-4 expression is related to the level of cellular differentiation in squamous epithelia and that it is not likely to be useful as an independent index of cellular proliferation or malignant behaviour.

Adult↗
PubMed1990

An immunohistochemical assessment of cellular proliferation markers in head and neck squamous cell cancers.

Prognostic information is essential for the evaluation, judgement and optimal treatment of patients with squamous cell cancers (SCCs) of the upper aerodigestive tract. Using immunohistochemical and flow cytometric techniques, we have studied the significance of cellular expression of the Ki-67 antigen, epidermal growth factor receptor (EGFR), the transferrin receptor (TFR) and DNA ploidy status in a prospective analysis of patients with SCCs of the head and neck region. All 42 fresh tumour samples (five well differentiated; 28 moderately differentiated; nine poorly differentiated) expressed both EGFR and TFR to varying degrees. Receptor expression was most marked on the peripheral invading margin of cancer cell islands although staining was also demonstrated in a random fashion within cellular islands and consistently along the basal cell layer of overlying stratified squamous epithelium. The percentage of cancer cells that reacted with the Ki-67 monoclonal antibody was assessed as low (less than 10%) in 15 samples (35.8%), intermediate (10-30%) in 19 samples (45.2%) and high (greater than 30%) in eight samples (19.0%). Eleven of 15 samples (73%) with a low percentage reactivity were DNA diploid, whereas seven of eight samples (87.5%) with a high percentage reactivity were DNA aneuploid. Poorly differentiated SCCs were significantly more often aneuploid than were either moderately or well differentiated tumours. Our results suggest that EGFR and TFR are widely distributed on SCCs, especially on proliferating cells at the invading tumour margin. In addition, there is a close spatial correlation between cells expressing EGFR, TFR and those expressing the Ki-67 antigen. Tumours in which the staining intensity for both EGFR and TFR was intense invariably expressed the Ki-67 antigen in a high proportion of cells. Further patient follow-up will be important in determining whether intense EGFR and TFR staining, combined with a high percentage reactivity with Ki-67 antibody and DNA aneuploidy, will ultimately define a subset of head and neck cancer patients with a poor clinical outcome.

Aged↗
PubMed1990

Comparative in situ hybridisation study of juvenile laryngeal papillomatosis in Papua New Guinea and Australia.

A comparative study of cases of juvenile laryngeal papillomatosis from Papua New Guinea (n = 3) and Brisbane, Australia (n = 9) was carried out. In situ hybridisation reactions for human papillomavirus (HPV) types 6 and 11 occurred in 11 cases. All three cases from Papua New Guinea and eight from Australia gave positive signals. A negative reaction was observed in one Australian case. The intensity of the reaction was strong in seven cases, moderate in one, and weak in three. An equivocal reaction was also noted with probes for types 16 and 18, and types 31, 33, and 35 in two cases from Australia and one from Papua New Guinea. It is concluded that as similar staining patterns and intensities occurred in cases from both areas, the aetiology is the same. The equivocal reactions noted in three cases were probably due to cross hybridisation rather than multiple infection.

Child↗
PubMed1989

Aetiology of branchial cysts.

The aetiology of branchial cysts is unknown. It is possible that they arise by more than one mechanism. The major theories are that they originate either from the branchial apparatus or from lymphoid tissues. A retrospective review was conducted of 61 cases occurring over a recent 14-year period. Eighty-five percent were diagnosed after the age of 10 years, 80% occurred in the 'classical' position, 80% had a squamous epithelial lining and 87% had lymphoid tissue in the wall. The clinical and histological features strongly support the lymphoid aetiology theory for the majority of branchial cysts.

Adolescent↗
PubMed1989

Metastatic brain tumours in Northern Ireland: a retrospective review in a closed community with emphasis on short term quality of life.

One hundred and nineteen consecutive patients with metastatic brain tumours who presented to the Provincial Neurosurgical Service in Northern Ireland were studied. The detection rate doubled after computerised tomography became available though the population in Northern Ireland over the years of study stayed relatively stable. Multiple tumours accounted for 38% while solitary tumours occurred mainly in the cerebellum or parietal lobe. Whereas 70% of patients presented with features of increased intracranial pressure and or lateralizing neurological signs, 20% had only vague symptoms. The primary site was lungs in a third of cases but in 33 cases (27.5%), the site of origin remained unknown. 42% of those 76 cases operated were adenocarcinoma. More than 80% of these patients in whom excision of the tumours were done, had a better quality of life at one month compared with improvement in only a third after biopsy.

Adenocarcinoma↗
PubMed1979

Nuclear diameter in parathyroid adenomas.

Nuclear diameter was measured in 55 parathyroid chief-cell adenomas to determine its value in histological diagnosis and to assess its relationship to other features of primary hyperparathyroidism. Mean nuclear diameter for the whole group of adenomas was significantly greater than that for the accompanying normal glands. Mean nuclear diameter in individual adenomas was significantly greater than that in the accompanying normal gland in 27 out of 34 cases. Nuclear diameter was correlated with tumour weight and with plasma calcium but was not correlated with duration of history. It was significantly greater in the group of patients with overt bone disease than in those with kidney stones and in those with neither kidney stones nor overt bone disease. Assessment of nuclear diameter is of value in histological diagnosis of parathyroid adenoma. The rate of growth of the adenoma may be a factor determining nuclear diameter.

Adenoma↗
PubMed1979

Pig Bel.

Pig Bel is a form of acute, segmental, necrotizing enteritis presenting as a common and life-threatening disease among the people (particularly the children) of the Highlands of Papua New Guinea. It relates to the consumption of pig meat and is thought to be caused by Clostridium welchii type C (an organism not usually present in the human intestine), the organism being transmitted to man by means of contaminated pig meat. Pig Bel resembles the diseases called "Darmbrand" which occurred in Northern Germany in the years that immediately followed World War II. Darmbrand was associated with a Clostridium welchii infection, possibly precipitated by malnutrition. It disappeared within a few years of its recognition. Conditions that closely resemble the clinical and pathological features of Pig Bel have been reported from Uganda and Thailand. In these countries, only a few cases have been encountered and they have not been associated with the eating of pig meat or with a clostridial infection.

Adolescent↗
PubMed1978

Research involving human subjects.

This article reports a study of the activities and performance of institutional review boards to protect human research subjects. Researchers and institutional review board members were generally supportive of the review system, although substantial criticisms were also heard. Institutional review boards had some direct impact on half of the proposals reviewed by requiring either modification of or additional information about proposed research. The data, however, raise questions about the effectiveness of some review board actions, for example, with regard to informed consent. Some policy implications of the study are presented.

Attitude↗