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Biomedical subjects

A Green

Publications and source records attributed to A Green.

At least 451 records · Page 25Linked to original sources
PubMed1990

Measurement and perception of skin colour in a skin cancer survey.

A population-based prevalence survey of skin cancer was conducted in Nambour, Queensland, in 1986. The skin colour of 807 participants was assessed in three ways: quantitatively, graded by a dermatologist, and self-reported. Quantitation of skin pigmentation was obtained by measuring the reflectance of light of wavelength 650 nm, at six sites. Females showed higher mean reflectance (paler skin) than males at all sites with the greatest difference on the lateral forearms. Prevalent skin cancer in males, and solar keratoses in both sexes were correlated with inherently pale skin colour on an unexposed site, and the presence of keratoses was correlated with darkly-pigmented backs of the hands (P less than 0.001). Both dermatologists' and participants' grading of skin colour were moderately correlated with measured skin colour. For dermatologists, correlation was highest with reflectance from the medial upper arms (r = 0.35, right arm; 0.30, left) in males, and the lateral forearms (r = 0.34, right; 0.38, left) in females. Correlations between reflectance values and self-reported innate skin colour were highest for the upper arms (r = 0.26, right; 0.24, left) in males, and for forearms (r = 0.42, right and left) in females. Prevalence of actinic lesions was more highly correlated with subjectively assessed skin colour than with quantitative skin pigmentation.

Adult↗
PubMed1990

A randomized double-blind, cross-over study of the linear and nonlinear algorithms for the QT sensing rate adaptive pacemaker.

We have compared the pacing rate responses during cardiopulmonary exercise testing in 11 patients (mean 59 years, six female) with implanted QT sensing rate adaptive pacemakers who were randomly programmed to 1-month periods in the linear and nonlinear algorithms using a double-blind, cross-over design. Exercise testing was performed at the end of each month block and symptoms were scored with the MacMaster questionnaire. With exercise, the time to a 10 beats/min increment in rate was significantly less with the nonlinear compared to the linear algorithm (126 sec vs 255 sec, P = 0.02) but there were no significant differences in exercise duration, the peak pacing rate, the peak VO2, the VO2 at the anaerobic threshold or the mean correlation coefficients of the pacing rate VO2 relationship. Rate oscillation occurred in seven patients in the linear algorithm and in two patients in the nonlinear setting. Initial deceleration of the pacing rate at the onset of exercise occurred in seven patients in the linear algorithm and in four patients in the nonlinear setting. The nonlinear algorithm is associated with a faster response time during exercise and fewer instances of rate instability. However, it has not overcome the problem of a dip in the pacing rate at the beginning of exercise. The major difference in the function of the two algorithms is faster initial acceleration with the nonlinear algorithm. This is explained by the significantly higher values of the slope setting at the lower rate limit for the nonlinear versus the linear algorithm (6.3 ms/ms vs 5.1 ms/ms).

Adult↗
PubMed1990

Rapid anticonvulsant monitoring in an epilepsy clinic.

The relevance of providing a rapid anticonvulsant monitoring service was assessed over a five year period at a paediatric epilepsy outpatient clinic. Altogether 481 drug assays were performed on 144 patients when considered clinically indicated. Drugs most frequently assayed were carbamazepine and sodium valproate, singly or in combination; sodium valproate, single or in combination; 90% of assays performed for phenytoin were from patients who were also taking another anticonvulsant. There were only six assays for ethosuximide and 10 for phenobarbitone. Physician's choice of drug dosage was recorded on a questionnaire before and after each assay result was known. Comprehensive patient details were analysed by a paediatric clinical pharmacologist, whose decision as to total daily anticonvulsant dosage was affected by knowledge of the drug concentration significantly less often than that of the clinicians for all the more commonly assayed drugs. There were a large number of drug assays that had no discernable clinical application. A more discriminating use of assays may both improve patient management and reduce considerably the number of anticonvulsant assays required.

Adolescent↗
PubMed1990

Sweat sodium and chloride concentrations--essential criteria for the diagnosis of cystic fibrosis in adults.

Criteria for a positive sweat test in children (sweat sodium greater than 60 mmol/L and sweat chloride greater than 70 mmol/L) were investigated in a series of adults aged between 18 and 40 years using the standard Gibson and Cooke technique of pilocarpine iontophoresis. A significant number of non-cystic fibrosis adults had sweat sodium values greater than 60 mmol/L whereas a concentration of chloride greater than 70 mmol/L always discriminated adults with cystic fibrosis from normal adults and those with chest disease not due to cystic fibrosis. In all cases of adult cystic fibrosis the sweat sodium concentration was greater than 80 mmol/L. The Na:Cl ratio and sum of Na and Cl provided additional helpful criteria in distinguishing between adults with and without cystic fibrosis.

Adolescent↗
PubMed1990

Expression of the multidrug resistance, MDR1, gene in neuroblastomas.

Metastatic neuroblastoma is a childhood malignancy that is frequently responsive to chemotherapy with doxorubicin, vincristine, and teniposide (VM26), among other drugs, but in the majority of treated patients, the tumor recurs during or after chemotherapy. In this work, we have examined the hypothesis that the development of resistance to chemotherapy in neuroblastoma might be related to the expression of the human MDR1 gene, which encodes a multidrug transporter that functions as an energy-dependent drug efflux pump. RNA samples from 49 neuroblastomas were analyzed, including 31 from untreated and 18 from treated patients. MDR1 RNA was detectable in the majority of treated and untreated tumors using a sensitive, semiquantitative slot blot assay. Of the samples from treated patients, five of 18 were found to have high MDR1 RNA levels, whereas only three of 31 from untreated patients had high MDR1 levels, a statistically significant difference (P less than .01). These results show that high levels of MDR1 RNA are often associated with resistance to chemotherapy in neuroblastoma and suggest that they may contribute to this resistance. Many of the neuroblastoma samples were also evaluated for N-myc amplification but there was no correlation between N-myc copy number and the level of MDR1 mRNA expression.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

The management of hydrothorax in continuous ambulatory peritoneal dialysis (CAPD).

Four patients on continuous ambulatory peritoneal dialysis (CAPD) developed large, symptomatic pleural effusions after commencing peritoneal dialysis. Pleuroperitoneal fistula in each case was diagnosed by the presence of a high glucose content in pleural fluid, with a normal corresponding blood sugar, and was confirmed by isotope or contrast peritoneography. Two patients had their effusions drained percutaneously, and then underwent pleural sclerosis with intracavitary tetracycline. Two patients had a thoracotomy performed, of which no fistula was identified in one case, and the other patient underwent pleurectomy. All four patients successfully recommenced CAPD several weeks after therapy, without recurrence of effusions. We conclude that pleuroperitoneal connections associated with CAPD do not mandate cessation of peritoneal dialysis and conversion to maintenance haemodialysis. Definitive diagnosis requires aspiration of pleural effusions for glucose estimation. Contrast or isotopic peritoneography is helpful in localising the fistula, but in our experience did not alter management. Simple sclerotherapy is effective and avoids the need for a formal thoracotomy.

Aged↗
PubMed1990

Familial adult medullary cystic disease with spastic quadriparesis: a new disease association.

We present two cases of familial adult medullary cystic disease with spastic quadriparesis, an association not previously described. Previous extrarenal associations of the nephronophthisis-medullary cystic disease complex were reported exclusively in childhood cases. Both patients have undergone successful cadaveric renal transplantation, with no evidence of their renal disease recurring. Further work is needed to elucidate the complex genetics of nephronophthisis.

Abnormalities, Multiple↗
PubMed1990

Prevalence of hereditary renal disease.

Little information is available concerning hereditary renal disease in the Irish population. We studied the prevalence and types of hereditary renal disease that lead to end stage renal failure by looking at the underlying hereditary disease in our dialysis populations and in all patients transplanted at the national unit. Twenty eight (15.7%) of 178 dialysis patients had hereditary renal disease with a mean age of 31 years (range nine to 65), and a male to female ratio of 1.54:1. Eighty-nine of 842 patients (10.3%) with renal transplants had hereditary renal disease with a male to female ratio of 1.63:1. The commonest entity was autosomal dominant polycystic kidney disease (68% in dialysis patients, 64% in transplants), and the next most frequent was Alport's syndrome (21.4%, 16.9%). Nephronophthisis was the third most common problem (10.7%, 10.1%) followed by hereditary non-Alport's nephritis, Fabry's disease, cystinosis and familial interstitial nephritis. The high prevalence of hereditary renal disease among the dialysis and renal transplant population emphasises the need for proper registration of the nature of renal disease in this group, and for a comprehensive genetic counselling service in this country.

Adolescent↗
PubMed1989

Peripheral primitive neuroectodermal tumor (peripheral neuroepithelioma) in children. A review of the St. Jude experience and controversies in diagnosis and management.

All patients diagnosed with primitive neuroectodermal tumor (PNET) and extraosseous Ewing's sarcoma in one institution between 1962 and 1987 were reviewed. Of the 26 cases studied, 16 had been diagnosed originally as PNETs, seven tumors were rediagnosed as PNET or EOE by histologic review, and three tumors had an original diagnosis of extraosseous Ewing's sarcoma. To determine whether these diagnoses determine a group of tumors with unique biologic behavior and identifiable pathologic characteristics, clinical and treatment response data were compiled, and electron microscopic and immunohistochemical studies were done for those patients with adequate samples. With combined modality therapy, this group achieved a substantially shorter disease control interval than patients with disseminated osseous Ewing's sarcoma or disseminated neuroblastoma--10.8 months versus 17 months and 16 months, respectively. The pattern of relapse and distant spread also differed among these tumor types. Immunohistochemical studies (for example, neuron-specific enolase and beta 2 microglobulin) were helpful in confirming the diagnosis but were not definitive in themselves. Tentative diagnostic criteria are proposed for use in studies designed to provide further information on the nature and treatment of PNET. Some of the controversies regarding diagnosis are discussed. The authors propose a uniform approach to treatment of extraosseous Ewing's sarcoma and PNET in order to try to clarify their relation.

Adolescent↗
PubMed1989

Characterization of human adipocyte adenosine receptors.

125I-Hydroxyphenylisopropyl adenosine (125I-HPIA) was used to characterize adenosine receptors in human adipocyte plasma membranes. Steady state binding was achieved after 6 h at 37 degrees. Scatchard plots were linear, with a KD of approx. 2.5 nM, and Bmax of 360-1800 fmol/mg protein. (-)N6-phenylisopropyl adenosine (PIA) was a more potent inhibitor of binding than N-ethyl carboxamido adenosine, and (+)PIA was more than 10-fold less potent than (-)PIA, consistent with A1 adenosine receptor binding. Theophylline was a potent inhibitor of binding (IC50 approx. 10 microM). Photoaffinity cross-linking studies demonstrated that the receptor is a single subunit, Mr approx. 43 kDa. The findings demonstrate that the human adipocyte adenosine receptor is similar to the A1 adenosine receptor of rat adipocytes, although its molecular weight is higher, and its affinity for HPIA is lower than that of the rat.

Adenosine↗
PubMed1989

Evidence for altered expression of the GTP-dependent regulatory proteins, Gs and Gi, in adipocytes from aged rats.

The alpha-subunits of Gi and Gs were quantified in adipocyte membranes from young (2-month) and older (18-month) rats by pertussis-toxin and cholera-toxin labelling respectively. Aging was associated with a 3-fold increase in Gi alpha-subunit, but only a 2-fold increase in one of the two Gs alpha-subunit species labelled. The findings may explain the altered sensitivity of adipocytes from aged rats to lipolytic and anti-lipolytic stimuli.

Adenylyl Cyclases↗
PubMed1989

Expression of a multidrug resistance gene in human cancers.

Many cancers have been cured by chemotherapeutic agents. However, other cancers are intrinsically drug resistant, and some acquire resistance following chemotherapy. Cloning of the cDNA for the human MDR1 gene (also known as PGY1), which encodes the multidrug efflux protein P-glycoprotein, has made it possible to measure levels of MDR1 RNA in human cancers. We report the levels of MDR1 RNA in greater than 400 human cancers. MDR1 RNA levels were usually elevated in untreated, intrinsically drug-resistant tumors, including those derived from the colon, kidney, adrenal gland, liver, and pancreas, as well as in carcinoid tumors, chronic myelogenous leukemia in blast crisis, and cell lines of non-small cell carcinoma of the lung (NSCLC) with neuroendocrine properties. MDR1 RNA levels were occasionally elevated in other untreated cancers, including neuroblastoma, acute lymphocytic leukemia (ALL) in adults, acute nonlymphocytic leukemia (ANLL) in adults, and indolent non-Hodgkin's lymphoma. MDR1 RNA levels were also increased in some cancers at relapse after chemotherapy, including ALL, ANLL, breast cancer, neuroblastoma, pheochromocytoma, and nodular, poorly differentiated lymphoma. Many types of drug-sensitive and drug-resistant tumors, including NSCLC and melanoma, contained undetectable or low levels of MDR1 RNA. The consistent association of MDR1 expression with several intrinsically resistant cancers and the increased expression of the MDR1 gene in certain cancers with acquired drug resistance indicate that the MDR1 gene contributes to multidrug resistance in many human cancers. Thus, evaluation of MDR1 gene expression may prove to be a valuable tool in the identification of individuals whose cancers are resistant to specific agents. The information may be useful in designing or altering chemotherapeutic protocols in these patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1989

Rhabdomyosarcoma, presenting as disseminated malignancy from an unknown primary site: a retrospective study of ten pediatric cases.

From 1962-1984, ten children were referred to St. Jude Children's Hospital with a metastatic poorly differentiated malignancy; extensive diagnostic workup had failed to disclose the site of the primary tumor. Multiple skeletal metastases as well as bone marrow involvement were common findings. Erythrocytes were detected in the cytoplasm of tumor cells in several cases, and cytochemical stains confirmed that these phagocytic cells did not have features of mononuclear phagocytes. Establishing a pathologic diagnosis in these cases was difficult, and most special studies including cytochemistry and electron microscopy were not helpful in elucidating the diagnosis. A diagnosis of rhabdomyosarcoma was made at presentation in six cases. In the remaining cases, the diagnosis of rhabdomyosarcoma was subsequently made after rebiopsy of new tumor masses during the course of the illness, by ultrastructural examination of a cell line derived from the tumor or at postmortem examination. Based on initial symptoms, clinical features, and postmortem findings, the primary tumor sites were assumed to be in the middle ear, paravertebral area, base of skull, retrobulbar space, chest wall, and retropancreatic area. In four patients the disease was confined to bone marrow, lymph nodes, and meninges so that a primary site could not be assigned. The approach to pediatric patients presenting with disseminated malignancy from an occult primary site should consist of an aggressive pursuit of a specific diagnosis and establishment of a primary site to better direct therapy, particularly for those children whose tumors may be responsive to specific therapy.

Adolescent↗
PubMed1989

Living related renal transplantation in Ireland: a sixteen year review.

Between January 1972 and December 1987, a total of 777 transplants were performed of which 135 (17%) were living related. There were 108 sibling donors, 25 parent to child and 2 child to parent. All sibling transplants were HLA identical. Conventional immunosuppression with Prednisone and Azathioprine was used in all cases. Actuarial patient survival were 95%, 91% and 88% at 1, 5 and 10 years respectively. Corresponding actuarial graft survivals were 90%, 80% and 60%. Graft survival in the sibling compared to the parent to child group was 87% versus 60% at 5 years. There were 13 deaths during the study interval and 32 grafts were lost. Five year patient/graft survivals of 91/80% compare favourably with other reported series. The poorer outcome in parent to child transplants has led us to modify the immunosuppressive protocol to include Cyclosporin A in this group. The increased availability and improved survival of cadaveric grafts in recent years and our one year patient/graft survival of 92/88% has led us to reduce emphasis on living related transplantation in our renal replacement programme.

Adolescent↗
PubMed1989

Systemic vasculitis with renal involvement--a review.

Twenty five patients with renal vasculitis presenting over an eight year period were reviewed. Ten had microscopic polyarteritis, 6 classic polyarteritis, 5 overlap syndrome, 2 Churg-Strauss syndrome and 2 Wegener's granulomatosis. Clinical features included hypertension, pulmonary involvement, neurological involvement and arthralgia. Serum creatinine was over 500 umol/l in 13 patients, 10 of whom required dialysis. Visceral angiography was positive in 80% of those studied, Focal and segmental necrotising glomerulonephritis was the commonest renal lesion. Treatment consisted of corticosteroids and cytotoxic agents in most cases. Plasmapheresis was used for rapidly progressive renal failure, severe pulmonary haemorrhage or cerebral vasculitis. Improvement or stabilisation of renal function was seen in 68% of patients treated. There were 4 early deaths and one late death. The diagnosis, histology, treatment and outcome of renal vasculitis is discussed. The importance of early diagnosis and treatment is emphasised in this potentially reversible cause of acute renal failure.

Acute Kidney Injury↗
PubMed1989

Attitudes of some young female bank employees to dentistry.

Structured interviews were undertaken with one hundred 18-30-year-old females, seeking their views on dental care. Almost all regarded their own past experience as affecting their general level of dental anxiety. Over half were anxious about visiting the dentist and almost all of these were anxious before entering the surgery. The Anxious emphasized the negative features in dental care and the practice environment whereas the Non-anxious concentrated on positive features, particularly their relationship with the dentist. Many spontaneously commented that their attitudes had been improved by changing dentists, although some still remained anxious. 'Worst visits' had frequently occurred early in their lives. Appearance was of prime importance; function was ignored. Interviewees believed that visiting the dentist would be eased by lower costs, more convenient hours, better surroundings in the practice and improved techniques to make dentistry more comfortable.

Adolescent↗