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Biomedical subjects

A Green

Publications and source records attributed to A Green.

At least 361 records · Page 20Linked to original sources
PubMed1993

Galactosaemia: results of the British Paediatric Surveillance Unit Study, 1988-90.

Ascertainment of cases of classical galactosaemia over a three year period in the UK and the Republic of Ireland, through the British Paediatric Surveillance Unit, identified 58 proved cases and two in whom the diagnosis was strongly suspected. One patient died at 4 days, and severe morbidity was no more frequent in babies diagnosed clinically because of their symptoms compared with those who were screened for galactosaemia. Treatment of four babies in the non-screened group was delayed until after 5 weeks of age, but it is concluded that all cases of galactosaemia could be diagnosed in an acceptable time without screening, providing clinical vigilance is maintained.

Age Factors↗
PubMed1993

Trauma on the Isle of Man.

The Isle of Man Tourist Trophy motorcycle races remain one of the most popular venues for motorcycle races. This is despite the reduced status of the event. The reason for the loss of world championship and formula one status is the nature of the road racing circuit itself. The twisting narrow roads are only closed to the public at certain times during the practice and race weeks. Motorcycling visitors to the event attempt to emulate their heroes on machines capable of high speeds. Casualties from both visitors and racers are dealt with efficiently by an expanded medical service. This includes the use of an aeromedical evacuation helicopter. Casualties from the visitors exceeded those from the racers themselves during the period reported.

Accidents, Traffic↗
PubMed1993

On choosing a baby's sex: what the future generation thinks, a preliminary survey.

The new biomedical techniques of reproduction, such as predetermination of a baby's sex, are gradually being initiated into formal practice in some countries such as Britain. This paper surveyed the attitudes of 60 academic and 60 nonacademic men and women between 18 and 20 years on whether they supported the idea of choosing a baby's sex. More than 75% of all participants rejected the idea of choosing a baby's sex, whilst only 20% agreed with the latter issue and a negligible number (4%) offered no opinion. Neither sex differences nor differences between academic/nonacademic population were significant. The results are discussed in relation to recent work on differences in attitudes between genders in academic and nonacademic settings.

Adolescent↗
PubMed1993

Low molecular weight GTP-binding proteins are altered in platelet hyperaggregation in IDDM.

We examined the hypothesis that hyperaggregating platelets from patients with insulin dependent diabetes mellitus (IDDM) have an alteration in location and function of the guanine nucleotide (GTP)-binding proteins. Platelets from 10 IDDM and 12 age-matched healthy control subjects were collected and washed. Thrombin-induced platelet aggregation (0.025 and 0.05 units for 60 seconds) was increased in IDDM (8.3 +/- 1.8% vs 22.3 +/- 4.4%, P < .05 and 49.9 +/- 7.3% vs 70.9 +/- 7.0%, P < .05). Four small molecular weight GTP-binding proteins were identified by binding of [32P]-GTP on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the cytosol and membranes of these platelets. Each showed specificity for binding [32P]-GTP by competitive inhibition with unlabeled GTP. The total of the 27/28 kDa proteins was decreased in the membrane fraction (414 +/- 30 vs 252 +/- 40 dpm micrograms-1 protein x min, P < .05) and increased in the cytosolic fraction (62 +/- 8 vs 129 +/- 21 dpm unit-1 LDH x min, P < .05) in IDDM. The 21 kDa protein (60.3 +/- 3.5 vs 45.4 +/- 2.9 dpm micrograms-1 protein x min, P < .05) was decreased in platelet membrane in persons with IDDM. In conclusion, increased platelet aggregation in IDDM is accompanied by an altered cellular distribution of a 27/28 kDa GTP-binding protein. These data suggest that the low molecular weight GTP-binding proteins of the 27/28 kDa range may play an important regulatory role in the hyperaggregatory platelets in diabetes.

Adult↗
PubMed1993

[The dead mother].

This study is not concerned, as the title might suggest, with the actual death of the mother but with the child's experience of a mother who is physically present but internally absent due to depression. The child simultaneously introjects and splits off the mother imago, making mourning and "burial" equally impossible. The consequence of this cathectic deprivation is what the author calls "psychic holes" or "white depression". Green attributes to the dead mother a similar structuring function for the psychic apparatus to that attributed to the dead father in Freud's Totem and Taboo, and places the dead mother complex side by side with the Oedipus complex.

Adolescent↗
PubMed1992

Establishment and characterization of four Sinclair swine cutaneous malignant melanoma cell lines.

Cutaneous malignant melanoma of Sinclair Swine (SSCM) is a heritable, congenital neoplasm which either proves fatal to the neonatal animal or undergoes spontaneous regression. Four SSCM cell lines, UISO-SSCM-433, UISO-SSCM-438, UISO-SSCM-5052, and UISO-SSCM-8093, were derived from biopsy specimens of primary tumors removed from swine at 26, 8, and 8 weeks of age, and 15 weeks gestation, respectively. Morphologic features, DOPA oxidase staining, and abnormal karyotype were suggestive of malignant melanoma. Each cell line was morphologically heterogeneous in culture with dendritic, spindle- and cuboidal-shaped cells. Pigmented melanosomes and DOPA oxidase activity were present in all cell lines at passages 20-22. UISO-SSCM-433 and UISO-SSCM-5052 contained hypodiploid and hypotetraploid sublines whereas UISO-SSCM-438 and UISO-SSCM-8093 were hypodiploid and hypotetraploid, respectively. At later passages, all cell lines presented evolutionary, karyotypic changes; the same chromosomes were involved in the alterations, however. Chromosomes 2, 6, 13, and 14 were the most affected, exhibiting numerical and structural alterations in all four cell lines. Despite the presence of multiple chromosomal anomalies in all cell lines, each with a unique set of chromosomal markers, clonal growth was not detected in soft agar, nor were any of the lines tumorigenic following s.c. inoculation in athymic mice. This suggests that the loss of malignant potential in SSCM may be inherent.

Animals↗
PubMed1992

Mortality from melanoma in migrants to Australia: variation by age at arrival and duration of stay.

All death records in Australia during the period 1964-1985 were analyzed to compare mortality from melanoma in immigrants and Australian-born individuals, and to investigate changes in risk in the immigrants according to their duration of stay and age at arrival. About 450,000 deaths were from cancer, and risks of melanoma were estimated by logistic regression relative to those of the Australian-born, with deaths from other cancers used as controls. Estimates were adjusted for age at death, time period, birth cohort, and state of registration of death in Australia. Region of birth was defined as New Zealand, other Oceania, England, Ireland/Scotland/Wales (including Northern Ireland and the Republic of Ireland), Central Europe, Eastern Europe, Southern Europe, Western Asia, or Eastern Asia, bearing in mind that many migrants born in Asia were of European descent. Overall, migrants from outside Oceania were at lower risk than the Australian-born, and the lowest risks in males were in Southern Europeans and Eastern Asians, reflecting the protective effect of a darker complexion. Risk of melanoma was related both to duration of stay in Australia and to age at arrival; although their relative importance cannot be measured, the patterns of change suggested that childhood migration may be more important in determining risk than number of years in Australia. The authors believe this study to be based on the largest data set ever used in migrant studies, and note that the previously found differences in melanoma risk between immigrants and Australian-born remained after adjustment for major temporal and geographic confounders. The results confirm the importance of the interaction between environmental and genetic risk factors in the etiology of melanoma.

Age Factors↗
PubMed1992

Incidence of childhood-onset insulin-dependent diabetes mellitus: the EURODIAB ACE Study.

EURODIAB ACE is a collaborative European study that was set up to assess incidence of childhood insulin-dependent diabetes mellitus (IDDM) in Europe, test the proposal of a south-north gradient, and to gather information to determine the causes and pathogenesis of the disease. Here, the basic epidemiological results are reported. Newly diagnosed cases of IDDM in children aged up to 15 years were identified prospectively in twenty-four geographically well-defined study regions in Europe and Israel (a total of 16.8 million children) during 1989 and 1990. 3060 cases were identified with estimated ascertainment rates exceeding 90% in all study regions. Age-standardised and sex-standardised incidence rates varied widely, ranging from 4.6 (northern Greece) to 42.9 (two regions in Finland) cases per 100,000 per year. Rates in southern Europe were generally higher than previously assumed, and there was an unexpectedly high incidence in Sardinia, which had the second highest rate (30.2 cases per 100,000 per year) recorded in Europe. Eastern European regions had generally low rates. The collaborative network now established provides a framework for further studies to examine the complex interaction between genetic and environmental factors in the cause and pathogenesis of IDDM.

Adolescent↗
PubMed1992

Gi down-regulation as a mechanism for heterologous desensitization in adipocytes.

Prolonged incubation of rat adipocytes with (-)N6-phenylisopropyl adenosine (PIA) (an A1 adenosine receptor agonist) leads to down-regulation of each of the three subtypes of Gi (Green, A., Johnson, J. L., and Milligan, G. (1990) J. Biol. Chem. 265, 5206-5210). To determine whether other inhibitors of adenylylcyclase would have similar actions, we incubated adipocytes in primary culture with PIA, prostaglandin E1 (PGE1), or nicotinic acid. After various times cells were homogenized, and crude membrane fractions were analyzed on Western blots using antipeptide antisera to alpha- and beta-subunits of G-proteins (SG1 (which binds to alpha i1 and alpha i2), I3B (which binds to alpha i3), BN2 (binds to beta-subunits) and CS1 (recognizes forms of alpha s)). PIA and PGE1 caused approximately 90% down-regulation of alpha i1 and alpha i3, and about 50% loss of alpha i2 and beta-subunits. In contrast, nicotinic acid at concentrations up to 1 mM had no effect on levels of any of these Gi subtypes. None of the compounds altered levels of either a 43- or 47-kDa form of alpha s. PIA caused about a 50% decrease in binding of [3H]DPCPX (an A1 adenosine receptor antagonist), indicating adenosine receptor down-regulation; however, neither PGE1 nor nicotinic acid treatment altered [3H]DPCPX binding. None of the treatments affected the activity of adenylylcyclase when measured in the presence of 100 microM forskolin and 10 mM Mn2+, indicating that the catalytic subunit of adenylylcyclase is not altered. To determine whether Gi down-regulation results in heterologous desensitization, we incubated adipocytes with maximally effective concentrations of PIA (300 nM), PGE1 (3 microM), or nicotinic acid (1 mM) for 4 days. The cells were then washed and incubated for an additional 30 min with various concentrations of these compounds to determine their ability to inhibit lipolysis. PIA caused a (marked) decrease in the sensitivity of the cells to both PIA and PGE1, thus indicating heterologous desensitization. Similarly, PGE1 decreased the sensitivity of the cells to both PGE1 and PIA, again demonstrating heterologous desensitization. In contrast, prolonged incubation with nicotinic acid decreased the sensitivity of the cells to nicotinic acid but had no effect on the sensitivity of the cells to PIA. Adenylylcyclase in membranes from PGE1-treated cells showed decreased sensitivity to inhibition by PIA. In contrast, adenylylcyclase showed normal sensitivity to PIA in membranes from nicotinic acid-treated cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Adenylyl Cyclases↗
PubMed1992

Fumarylacetoacetase activity in cultured and non-cultured chorionic villus cells, and assay in two high-risk pregnancies.

We describe further development of the fumarylacetoacetase (FAA) assay for the prenatal diagnosis of tyrosinaemia type 1 using chorionic villus sampling (CVS). We have established a reference range for FAA activity in cultured villus cells and have confirmed previously reported data on the FAA activity in uncultured chorionic villus cells. This should allow confirmation of results using CVS, without the need for further invasive procedures. We report the FAA enzyme stability at -70 degrees C, +4 degrees C, and at room temperature, and we have shown no obvious difference in enzyme activity with gestational age. We have analysed cultured and non-cultured CVS activity of FAA in two pregnancies at risk of tyrosinaemia type 1. In both, the fetus was designated unaffected, and these results were confirmed postnatally.

Cells, Cultured↗
PubMed1992

A theory of site distribution of melanomas: Queensland, Australia.

Although sun exposure is believed to be associated causally with cutaneous melanoma, the high incidence on less sun-exposed areas such as the back, as well as on chronically exposed sites such as the face, suggests that the association with sunlight is less straightforward than for other skin cancers. To explain this enigmatic site distribution, a theory of site-dependent susceptibility of melanocytes to malignant transformation is proposed. As possible evidence, all melanomas diagnosed in the state of Queensland, Australia, over a one-year period were surveyed for histologic evidence of benign melanocytic nevus cells adjacent to the melanoma, and analyzed according to anatomic distribution. Results showed a regional variation in the proportion of melanomas with adjacent nevi not explicable by regional variation in nevus density, which suggests that there is a varying susceptibility of nevi to malignant change. Given that nevus cells are equivalent to melanocytes, this finding would support the hypothesis that melanocytes at-large have a differential response to the mitogenic stimulus of sunlight according to anatomic site.

Adult↗
PubMed1992

Increasing incidence of early onset type 1 (insulin-dependent) diabetes mellitus: a study of Danish male birth cohorts.

To provide information of the incidence trends of Type 1 (insulin-dependent) diabetes mellitus we performed a cohort study of a series of Danish male birth cohorts. All male livebirths in Denmark between 1 January 1949 and 31 December 1964, were investigated regarding the development of Type 1 diabetes during the first 20 years of life using the files of the Danish Conscript Board, supplemented by a search in the Danish National Registry of Deaths. Diagnosis was verified and clinical information obtained from medical records. The material is estimated to be more than 95% complete. A total of 1705 diabetic subjects were identified of whom 23 were not representative of idiopathic Type 1 diabetes. The cumulative rate of Type 1 diabetes development during the first 20 years of life increased from 2.37 to 2.90 per 1000 for the first eight and last eight birth cohorts, respectively. A log-linear analysis of the incidence revealed significantly increasing incidence rates, independent of age effects, with a maximum in the late 1970's. About 75% of the cases presented short duration of symptoms prior to diagnosis, and only very few cases were diagnosed incidentally. Cases were diagnosed relatively less frequently during summer months than during winter months.

Adolescent↗
PubMed1992

Sun exposure in Australian adolescents.

BACKGROUND: Little information is available on the sun-related behavior of teenagers despite the considerable resources spent to decrease sun exposure in this age group. OBJECTIVE: Our purpose was to describe the sun exposure behavior of Australian adolescents and define characteristics that predict use of sun protection. METHODS: Cross-sectional study of a random sample of 972 school students 13 to 15 years of age from three different locations in Australia (two urban and one rural) using a diary to document sun exposure and sun protection on two consecutive weekends. RESULTS: More than 80% of adolescent boys in each place and more than 60% of adolescent girls in both of the large cities spent more than 2 hours outdoors during the peak ultraviolet (UV) periods on each weekend. Neither sunscreen nor hats were used for more than half the time spent in the sun; however, shirts were worn most of the time. Students who wore hats were more likely to be boys (odds ratios [OR] = 2.2, 95% confidence intervals [CI] 1.40 to 3.44) and live in the rural region (OR = 4.6, 95% CI 2.36 to 9.04). Students who used sunscreen tended to have skin that sunburned easily (OR = 3.2, 95% CI 1.27 to 7.88) and score highly on the knowledge questions (OR = 2.9, 95% CI 1.46-5.69). This model was not a good predictor of behavior on a subsequent weekend, possibly because behavior was highly variable, with 35% to 50% of students changing their pattern of protection use from one weekend to the next. CONCLUSION: Adolescents spend long periods on summer weekends in the sun and do not follow recommended sun protection guidelines. The high variability of sun-related behavior makes modeling and consequent development of education programs a difficult task.

Adolescent↗