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P Smith

Publications and source records attributed to P Smith.

At least 19 recordsLinked to original sources
PubMed1992

Developmental regulation and neuronal expression of the mRNA of rat n-chimaerin, a p21rac GAP:cDNA sequence.

Human n-chimaerin is a GTPase-activating protein (GAP) for p21rac and a phorbol ester receptor. We have isolated rat n-chimaerin cDNA and investigated the cellular and developmental pattern of mRNA expression in the brain. There is extensive sequence conservation with human n-chimaerin in the coding region and the first 400 nucleotides of the 3'-untranslated region (UTR) (90% and 83% identity respectively). The rat cDNA encodes an additional 35 N-terminal amino acids compared with the reported human cDNA, which has a 5'-UTR sequence inversion and a 41-nucleotide deletion including the putative initiator methionine. The rat cDNA encodes a 334-amino acid protein (38200 M(r), pI 8.04) with 97% amino acid sequence identity with the human protein, after correction of the human 5'-DNA sequence. n-Chimaerin mRNA was detectable in embryonic rat brain at day 15 and increased in amount postnatally from birth to 20 days, coincident with cellular differentiation and synaptogenesis. n-Chimaerin mRNA is restricted to neurons, with highest concentrations in hippocampal pyramidal cells, granule cells of the dentate gyrus and cortical neurons. In the cerebellum the mRNA was detected only in Purkinje neurons. The pattern and specificity of mRNA expression suggests an important role for n-chimaerin in neuronal signal-transduction mechanisms.

Amino Acid Sequence↗
PubMed1992

Distant disease.

Explore the source record for details and available documents.

Androgen Antagonists↗
PubMed1992

Acute and long-term effects on myocardial ischemia of intermittent and continuous transdermal nitrate therapy in stable angina.

The aim of this study was to compare the efficacy and safety of continuous and intermittent transdermal nitrate therapy using ambulatory electrocardiographic (Holter) monitoring. Eighty-five patients with stable angina pectoris and positive exercise test results participated during their concomitant antiischemic medication in a randomized open trial lasting 12 weeks. After a 3-week run-in period with continuous therapy (10 mg/24 hours), patients were randomized to either continuous- or intermittent-therapy groups. In the intermittent-therapy group the patients removed their patch at night (the mean patch-off period was 10 hours). Forty-eight-hour Holter monitoring was performed in each patient after randomization, and again after 2 and 12 weeks. Eighteen patients withdrew, 9 in each group. A total of 11,194 hours of electrocardiography were recorded and 607 ischemic episodes were detected, of which 79% were asymptomatic and 95% appeared during daytime. The number of ischemic episodes per 48 hours with intermittent therapy was 3.1 +/- 0.7 (mean +/- SEM) after randomization, 1.8 +/- 0.4 at 2 weeks and 2.0 +/- 0.6 at 12 weeks. With continuous therapy the respective numbers were 3.8 +/- 1.1, 3.5 +/- 0.9 and 4.2 +/- 1.2. The differences were not statistically significant because a large number of patients (30%) had no ischemic episodes on Holter recording. However, when examining 47 patients with episodes during the study, the number of episodes was significantly reduced in the intermittent-therapy group (p less than 0.05 at 12 weeks). The changes in asymptomatic and symptomatic episodes were concordant. No changes and differences between the treatment groups were seen in nighttime episodes.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Cutaneous↗
PubMed1992

Effects of long-term treatment with warfarin on fibrinogen, FPA, TAT, and D-dimer in patients with coronary artery disease.

Sixty-four patients undergoing aorto-coronary bypass surgery were randomized to receive antithrombotic treatment with acetylsalicylic acid (ASA), 300 mg/d (n = 30) or warfarin, INR = 2.5 - 4.2 (n = 34). The levels of fibrinogen, thrombin-antithrombin III complexes (TAT), fibrinopeptide A (FPA) and D-dimer were assessed before surgery and 9 months postoperatively. In the warfarin treated group the fibrinogen levels were increased after 9 months, while the levels of TAT, FPA and D-dimer were decreased. In the ASA group TAT levels were increased at 9 months, whereas no significant changes in fibrinogen, FPA or D-dimer from baseline were noted. Thus, a reduced activation of the coagulation system has been demonstrated during long-term treatment with warfarin in patients with coronary artery disease.

Adult↗
PubMed1992

Antiphospholipid antibodies after myocardial infarction and their relation to mortality, reinfarction, and non-haemorrhagic stroke.

Antiphospholipid antibodies have been suggested as markers for a high risk of recurrent cardiovascular events in young survivors of an acute myocardial infarction. However, there are few data to confirm or refute this hypothesis. In a cohort study, we have measured anticephalin (aCEPHA) and anticardiolipin (aCL) antibodies in a group of patients surviving an acute infarct. Of 597 patients studied, 13.2% were IgG or IgM aCEPHA positive compared with 4.4% of a reference population (n = 158; p = 0.002). In a multivariate analysis, adjusted for major cardiovascular risk factors, neither aCEPHA (IgG or IgM) nor a CL (IgG or IgM) was an independent risk factor for mortality, reinfarction, or non-haemorrhagic stroke. Although an increased proportion of survivors of a myocardial infarction have antiphospholipid antibodies, the presence of such antibodies is not a risk factor for subsequent coronary or cerebrovascular thrombosis.

Adult↗
PubMed1992

Tooth components of mandibular deciduous molars of Homo sapiens sapiens and Homo sapiens neanderthalensis: a radiographic study.

Tooth components of deciduous molars were measured from standardized radiographs of Homo sapiens sapiens and Homo sapiens neanderthalensis. Enamel height and width were greater in deciduous teeth of Homo sapiens sapiens than in Homo sapiens neanderthalensis and the differences were statistically significant (p less than 0.01). Dentin height showed no significant differences between the two groups, but enamel to floor of pulp chamber and pulp height and width dimensions were significantly greater in Homo sapiens neanderthalensis. Discriminant analysis carried out between groups, using deciduous tooth components, showed an accuracy of 98-100% for identification of Homo sapiens sapiens and 83-92% for identification of Homo sapiens neanderthalensis. The results obtained in this study on dental dimensions support the hypothesis of a distinct evolutionary line for Neanderthals.

Animals↗
PubMed1992

The ultrastructure of pulmonary arteries and arterioles in emphysema.

The lungs from three cases of pulmonary emphysema obtained at heart-lung transplantation were examined by electron microscopy to determine the origin of intimal longitudinal muscle and the formation of muscular tubes in small pulmonary arteries and arterioles. The earliest change consisted of migration of mature smooth muscle cells from the media of small pulmonary arteries, through gaps in the internal elastic lamina, into the subendothelial space. Most of these cells then adopted a longitudinal orientation, maintained a muscular phenotype, and became enmeshed in a web of elastic fibres. A small minority, immediately subjacent to the endothelium, were orientated circularly and, in some vessels, were enclosed by rudimentary internal and external elastic laminae to form early muscular tubes. Pulmonary arterioles, which are normally devoid of a media, contained several layers of circularly orientated smooth muscle cells, some of which also formed muscular tubes. It is postulated that the limited migration of mature smooth muscle cells seen in states of chronic hypoxia is mediated by a different stimulus from that causing the florid invasion of the intima by immature smooth muscle, with subsequent transformation into myofibroblasts, which characterize plexogenic pulmonary arteriopathy.

Adult↗
PubMed1992

KiS1--a novel monoclonal antibody which recognizes proliferating cells: evaluation of its relationship to prognosis in mammary carcinoma.

Immunohistochemical staining with a novel monoclonal antibody, KiS1, which recognizes a cell cycle-associated antigen, was investigated in 142 cases of stage I and II invasive breast carcinoma. KiS1 staining indices were compared with disease-free interval, overall survival, and post-relapse survival. Using a semi-quantitative method of assessment, we found that tumours with a high level of staining (34/142, 24 per cent) had a significantly worse prognosis than those with a low level of staining (108/142, 76 per cent). Significant correlations were found between KiS1 staining and disease-free interval (P < 0.001), overall survival (P < 0.001), and post-relapse survival (P = 0.008). A more time-consuming, quantitative method of assessment gave similar results. Cox multivariate analysis showed these results to be independent of nodal status, histological type, and grade of tumour (P = 0.01). We conclude that KiS1 is a valuable new antibody which affords useful prognostic information in breast carcinoma. As it can be used in formalin-fixed, paraffin-embedded material, it may be of particular use in the study of small lesions such as those identified in the Breast Cancer Screening Programme.

Adult↗
PubMed1992

Osteogenic sarcoma and Rothmund Thomson syndrome.

Rothmund Thomson syndrome (RTS) is a rare autosomal recessive disorder characterised by poikiloderma, dermal atrophy, dystrophic nails, short stature and hypogonadism. An increased incidence of malignancy has been reported in patients with this syndrome secondary, it is postulated, to DNA repair defects. We report the occurrence of an osteogenic sarcoma in an 11-year-old Irish girl with RTS. Although fibroblast cultures demonstrated enhanced radiosensitivity, there was no undue toxicity associated with treatment, which included methotrexate, cisplatinum and Adriamycin. Following conservative surgery, she is currently off treatment and disease-free 2 years from diagnosis.

Abnormalities, Multiple↗
PubMed1992

Mitotic instability of integrated plasmids in Penicillium chrysogenum transformants.

Transformation vectors based on the Streptoalloteichus hindustanus phleomycin-resistance gene placed under the control of either the Penicillium chrysogenum trpC or pcbC promoters were constructed (plasmids pGS1 and pGS7 respectively). Up to 100 transformants per microgram of DNA were obtained with pGS7 in P. chrysogenum strain P2. In order to follow the expression of additional penicillin biosynthetic genes introduced by transformation, a pcbC::lacZ gene fusion was introduced into pGS1, generating pGS6. Southern analysis of three pGS6 transformants indicated that the plasmid was integrated in tandem arrays. Revertants which had lost the exogenous beta-galactosidase activity, were detected for each transformant after several cycles of subculture on non-selective medium. Southern analysis indicated that the different phenotypes obtained resulted from the loss of part or all of the integrated plasmid copies.

Blotting, Southern↗
PubMed1992

Long-term anticoagulant treatment after acute myocardial infarction. The Warfarin Re-Infarction Study.

High levels of fibrinogen and clotting factor VII are associated with an increased risk for subsequent death and cardiovascular disease in apparently healthy individuals. Furthermore, pathoanatomic studies and coronary angiography have confirmed a relationship between coronary thrombus formation and acute Q-wave infarction. Effective antithrombotic agents may prevent or limit thrombus formation and events related to thrombosis. The Warfarin Re-Infarction Study (WARIS) studied the effect of warfarin in survivors of acute myocardial infarction. Patients aged 75 years or less were randomized in a double-blind, placebo-controlled study to test whether long-term treatment with warfarin reduces the risk of death, reinfarction, and thromboembolic morbidity. A total of 1918 patients were screened for participation; 1214 were recruited. The mean follow-up was 37 months. Analyzed on an intention-to-treat basis, 123 (20%) in the placebo group died, versus 94 (15%) in the warfarin group, a risk reduction of 24% (P = 0.026). Considering patients on treatment or within 28 days after discontinuing the test medication, 92 in the placebo group died, as compared with 60 of the warfarin-treated patients, a risk reduction of 35% (P = 0.005). Relapsing myocardial infarction (fatal and nonfatal) was reduced by 43% (P = 0.0001). The incidence of cerebrovascular attacks was lower in the warfarin group (16 patients) than the placebo group (41 patients), a highly significant reduction of 61% (P = 0.0003). Serious bleeding occurred in 11 patients taking warfarin, an incidence of 0.6% per year. In conclusion, long-term anticoagulant therapy may be recommended after acute myocardial infarction.

Aged↗
PubMed1992

Expression of the ERBB3 gene product in breast cancer.

Abnormalities of the EGF receptor and/or the related ERBB2 receptor occur in a significant proportion of cases of human breast cancer and are important influences in the behaviour of this tumour type. In this report we demonstrate by nucleic acid analysis and immunohistochemistry that the recently recognised third member of this gene family, ERBB3, shows a wide range of expression in breast cancer, and shows stronger immunoreactivity than that observed in normal tissue in 43 out of 195 cases (22%) of primary breast cancer. Overexpression of ERBB3 appears to result from increased levels of gene transcription since in none of the cell lines or primary cancers analysed did we find evidence of gene amplification. High expression of ERBB3 is positively associated with the presence of lymph node metastases, but there was no demonstrable relationship with patient survival in this series.

Blotting, Southern↗
PubMed1992

Persistent infection with Chlamydia pneumoniae following acute respiratory illness.

Chlamydia pneumoniae is emerging as a significant cause of respiratory disease, including pneumonia and bronchitis, in humans. In this recently completed study of infection due to C. pneumoniae in patients presenting with pneumonia to SUNY Health Science Center at Brooklyn, we identified two individuals for whom cultures were positive on multiple occasions over a 1-year period. To determine the frequency of persistent respiratory infection with C. pneumoniae, follow-up specimens were obtained from nine individuals with culture-documented C. pneumoniae infection. Five of these individuals had persistent infection: four had a flulike illness characterized by pharyngitis, and one had bronchitis with prominent bronchospasm. All five individuals appeared to have acute C. pneumoniae infection as determined by results of serologic tests (titers of IgM antibody for all individuals were greater than or equal to 1:16). For three patients, cultures remained positive for 11 months despite therapy with 10- to 21-day courses of tetracycline or doxycycline. These observations suggest that persistent infection with C. pneumoniae may follow acute infection and may persist for many months. Infection with C. pneumoniae may be very difficult to eradicate with use of currently available antibiotics even if there is a clinical response to therapy.

Acute Disease↗
PubMed1992

Doppler haemodynamic profiles of clinically and echocardiographically normal mitral and aortic valve prostheses.

Doppler echocardiographic studies were performed in 380 consecutive patients with 415 normally functioning artificial valves to establish normal Doppler characteristics for each type of prostheses used in our institution, with particular reference to Starr-Edwards valves, and to serve as control studies for future assessment. None of the patients were in heart failure at the time of the study. Peak transaortic velocities (m.s-1) were higher and effective orifice areas (cm2) smaller in mechanical valves as a whole, when compared with bioprostheses (P less than 0.01); 2.7 +/- 0.7 and 1.4 +/- 0.55 for Starr-Edwards, 2.7 +/- 0.6 and 1.5 +/- 0.6 for Bjork-Shiley, 1.8 +/- 0.1 and 1.5 +/- 0.6 for Duromedics and 1.5 +/- 0.06 and 2 +/- 0.12 for bioprostheses, respectively. In the mitral position, the average peak diastolic velocities (m. s-1) and pressure half-times (ms) were higher in mechanical valves, but there was a large overlap between the various types and sizes of prostheses (P = NS); 1.6 +/- 0.3 and 98 +/- 25 for Starr-Edwards, 1.4 +/- 0.3 and 88 +/- 26 for Bjork-Shiley, 1.8 +/- 0.1 and 75 +/- 5 for Duromedics and 1.5 +/- 0.3 and 90 +/- 20 for bioprostheses, respectively. There was an inverse relation between valve size and pressure halftime for Starr-Edwards prostheses (P less than 0.01). Doppler flow characteristics in mechanical valves where similar in patients with normal and dysfunctioning prostheses. Valvular or myocardial dysfunction could best be ascertained when early postoperative studies were available for comparison.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗