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S Davis

Publications and source records attributed to S Davis.

At least 307 records · Page 17Linked to original sources
PubMed1991

Presence of an SH2 domain in the actin-binding protein tensin.

The molecular cloning of the complementary DNA coding for a 90-kilodalton fragment of tensin, an actin-binding component of focal contacts and other submembraneous cytoskeletal structures, is reported. The derived amino acid sequence revealed the presence of a Src homology 2 (SH2) domain. This domain is shared by a number of signal transduction proteins including nonreceptor tyrosine kinases such as Abl, Fps, Src, and Src family members, the transforming protein Crk, phospholipase C-gamma 1, PI-3 (phosphatidylinositol) kinase, and guanosine triphosphatase-activating protein (GAP). Like the SH2 domain found in Src, Crk, and Abl, the SH2 domain of tensin bound specifically to a number of phosphotyrosine-containing proteins from v-src-transformed cells. Tensin was also found to be phosphorylated on tyrosine residues. These findings suggest that by possessing both actin-binding and phosphotyrosine-binding activities and being itself a target for tyrosine kinases, tensin may link signal transduction pathways with the cytoskeleton.

Actins↗
PubMed1991

Wood dust exposure and squamous cell cancers of the upper respiratory tract.

While it is well-accepted that exposure to hardwood dust increases the risk of sinonasal adenocarcinoma, it is still not clear to what extent wood dust exposure increases the risk of sinonasal squamous cell carcinoma or whether such exposure is also associated with adjacent upper respiratory sites. These questions were addressed using data from two population-based case-control studies in Washington State in 1979-1987. After control for major risk factors, employment in wood-related occupations was most strongly associated with nasal cancer, especially when analysis was restricted to long-term employment 15 or more years before diagnosis (odds ratio = 7.3; 95% confidence interval 1.4-34.2). Although the overall risk for the nasopharynx was only slightly elevated, similar analysis restrictions increased the odds ratio to 4.2 (95% confidence interval 0.4-26.6). There was little indication of increased risk for the oropharynx or larynx. Although based on small numbers, these findings suggest that exposure to softwood dust increases the risk of both sinonasal and nasopharyngeal squamous cell cancers.

Carcinoma, Squamous Cell↗
PubMed1991

Functional respiratory chain studies in mitochondrial cytopathies. Support for mitochondrial DNA heteroplasmy in myoclonus epilepsy and ragged red fibers (MERRF) syndrome.

Mitochondrial respiratory chain function was investigated with polarographic and enzymatic studies, and correlated with immunoblot studies using a battery of probes against respiratory chain holocomplexes in a series of patients with myoclonus epilepsy and ragged red fibers (MERRF) syndrome. State III respiration rates in intact skeletal muscle mitochondria were normal in two cases, suggested site I deficiency in one case and a mid-respiratory defect in another. Immunological studies of complex I showed reduced levels of several subunits with the apparent absence of two bands (which at 45 and 42 kDa, coincide with the predicted electrophoretic mobility of the ND5 gene product) in one case. Complex I, III and IV composition was normal in the other three cases indicating no major disruption of complex assembly. A differing severity of skeletal muscle respiratory chain impairment in a group of unrelated patients with severe cerebral clinical involvement is best explained by uneven tissue distribution between brain and muscle of a heteroplasmic mtDNA mutation. The relationship between MERRF and mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) encephalopathies is reappraised by extension of this hypothesis.

Adult↗
PubMed1991

Myeloid leukaemia following therapy for a first primary cancer.

To evaluate the risk of second primary myeloid leukaemia due to radiotherapy and chemotherapy administered for a first primary cancer, we conducted a population-based case-control study consisting of 97 cases and 194 controls matched on age, date of diagnosis, and site of initial primary cancer among residents of 13 counties in western Washington State. The risk of myeloid leukaemia in patients who received cyclophosphamide as part of their chemotherapy regimen was 7.4 (95% confidence interval 1.3-43.8). This risk was not altered appreciably by the administration of radiotherapy. Compared to patients not receiving any chemotherapy, the relative risk among patients who received prednisone in combination with cyclophosphamide (odds ratio 44.4 95% confidence interval 4.0-496.2) was nearly four times that among patients receiving cyclophosphamide without this steroid (odds ratio 12.6 95% confidence interval 2.4-64.9). The relative risk of second primary myeloid leukaemia in patients who received both prednisone and drugs other than cyclophosphamide (odds ratio 64.2 95% confidence interval 2.6-1582) was 20 times that among patients receiving drugs other than cyclophosphamide and no prednisone (odds ratio 3.2 95% confidence interval 0.6-16.9). These risk estimates were higher when the analysis was restricted to acute myeloid leukaemia. There was no increased risk of second primary myeloid leukaemia associated with radiotherapy. The single unique finding is that the use of prednisone in chemotherapy regimens may enhance the leukaemogenic effect of other chemotherapy drugs.

Acute Disease↗
PubMed1991

The effect of an informational newsletter on control participation rates: a randomized study.

We employed a randomized study of 344 subjects to determine whether an initial contact letter accompanied by an informational newsletter increased participation in a population-based case-control study. The results indicated that there was no benefit in including a newsletter with a letter of introduction. There may have been a slight detrimental effect, since those who received the newsletter were less likely to consent to an in-person interview (82%) than those who did not (88%).

Adult↗
PubMed1991

Surgical risk of hemorrhage in cerebral amyloid angiopathy.

Cerebral amyloid angiopathy is increasingly recognized as a cause of lobar cerebral hemorrhage in normotensive elderly individuals. Isolated reports have suggested that neurosurgical intervention entails a high risk of precipitated hemorrhage. We identified 16 pathologically confirmed cases of cerebral amyloid angiopathy. Fourteen of these patients presented with lobar cerebral hemorrhage. Fifteen neurosurgical procedures in eight patients included eight clot evacuations, three abscess drainage procedures, two ventriculoperitoneal shunts, one biopsy, and one lobectomy. Recurrent postoperative cerebral hemorrhage was seen in four patients at 2 days, 9 days, 6 weeks, and 10 months, but surgery was thought to have precipitated the cerebral hemorrhage in only one patient. Recurrent cerebral hemorrhage also was seen in two of the eight nonoperated cases. Recurrent cerebral hemorrhage is characteristic of cerebral amyloid angiopathy, but we conclude that neurosurgical intervention, particularly evacuation of hematomas, is not associated with major risk of precipitated hemorrhage.

Aged↗
PubMed1991

Violence by psychiatric inpatients: a review.

The literature on violence by psychiatric inpatients provides some evidence that rates of violence may be increasing over time and that they are higher in the United States than in other nations. This review examines the extent of inpatient violence and describes the individual, situational, and structural factors with which it is associated. Individual factors include acute illness, psychosis, drug abuse, age, and history of violence. Situational variables include overcrowding, provocation, staff inexperience, and management tolerance of violence. Structural factors include changes in mental health policy that have made dangerousness a frequent criterion for commitment and a shortage of treatment resources. The author concludes that violence is the result of an interaction between the various types of factors and is not simply an expression of individual pathology.

Cross-Sectional Studies↗
PubMed1991

Comparison of iohexol with barium in gastrointestinal studies of infants and children.

This study evaluates iohexol as a contrast agent in the gastrointestinal tract in children. In the first part of the study, iohexol in concentrations of 180 and 300 mg l/ml was compared in double-blind manner with barium. Sixty-four patients were studied. No significant difference in changes of blood pressure and pulse rate was found between the three groups of patients studied. Diarrhea was significantly more common in the children receiving iohexol than in children receiving barium. The diarrhea was not due to previously identified high-risk factors in the children, nor was it due to concurrent medication. When image quality was assessed in each anatomic region of the gastrointestinal tract, fewer nondiagnostic ratings occurred with barium than with iohexol. With barium, fewer ratings of poor mucosal coating and slightly fewer ratings of suboptimal contrast density occurred. The second part of the study was an open evaluation of iohexol 180 mg l/ml in 18 patients in whom barium was clinically contraindicated. Three of 53 assessments were nondiagnostic. Mucosal coating was poor in 6%, and contrast density was suboptimal in 8% of patients. The results of this study indicate that barium is the preferred contrast agent for routine evaluation of the gastrointestinal tract in children. Good-quality images can be obtained, however, with iohexol in concentrations of 180 or 300 mg l/ml, and iohexol is an excellent contrast agent for evaluation of the gastrointestinal tract in those patients in whom barium is relatively or absolutely contraindicated.

Adolescent↗
PubMed1991

Management of transient ischaemic attacks.

There have been major recent advances in the investigation and treatment of transient ischaemic attacks, which represent an important prodrome of cerebral infarction. Medical therapy with aspirin reduces stroke risk, while warfarin has an important place in the prevention of cardiogenic cerebral embolism. Carotid endarterectomy is of proven value in symptomatic patients with severe carotid stenosis.

Aspirin↗
PubMed1991

Clinical applications of carbon dioxide/digital subtraction arteriography.

During an 18-month period 33 patients in whom there were contraindications to the use of iodinated contrast arteriography underwent 40 carbon dioxide/digital subtraction arteriograms for lower extremity ischemia (19), severe hypertension and renal insufficiency (12), or arterial aneurysm (2). Contraindications to iodinated contrast agents included renal insufficiency, congestive heart failure, and contrast hypersensitivity. Sixteen aortic, 15 iliac-femoral-popliteal-tibial, five aorta-iliac-femoral and four aorta-iliac-femoral-popliteal-tibial carbon dioxide/digital subtraction arteriography studies were performed. In 11 studies, imaging of selected arterial segments required the addition of 10 to 60 ml of dilute nonionic contrast. Guided by carbon dioxide/digital subtraction arteriography studies four femoral-tibial bypasses, three aneurysmorrhaphies, two aortorenal bypasses, one aortofemoral bypass and one femoral-femoral bypass were successfully performed in 11 patients. In addition, carbon dioxide/digital subtraction arteriography directed angioplasties of the common iliac (4), superficial femoral (6), popliteal (3), or tibioperoneal trunk (1) were performed in 10 patients. Complications of carbon dioxide/digital subtraction arteriography included transient deterioration in renal function in three patients in whom 20 ml of nonionic contrast was used, a nonfatal myocardial infarction after a popliteal percutaneous transluminal angioplasty in one patient, and transient tachypnea and tachycardia during a carbon dioxide/digital subtraction arteriography study in one patient. Diagnostic arteriograms are obtainable using carbon dioxide as the contrast agent. Carbon dioxide/digital subtraction arteriography permits patients with symptomatic arterial disease at high risk for contrast related complications to safely undergo arteriography and subsequent arterial reconstruction or endovascular intervention.

Adult↗
PubMed1991

Oral protein intake and the risk of acute graft-versus-host disease after allogeneic marrow transplantation.

The possibility that antigenically active protein macromolecules affect the risk of developing acute graft-versus-host disease (aGVHD) was investigated in a cohort of patients who underwent allogeneic marrow transplantation for hematologic malignancy (n = 575). Daily records of food intake from transplant through discharge or death were evaluated for grams of total protein and summed over consecutive 4-day intervals. The day of onset of aGVHD was partitioned into 4-day time intervals such that assessments of food intake preceded onset of aGVHD by 3-6 days. Acute GVHD developed in 308 (54%) patients. The cumulative incidence of aGVHD among patients eating any amount of protein was lower (4-13%) than that of patients not eating protein (8-19%) for each of the time intervals through day 21 post-transplant; the relative risk associated with protein intake, adjusted for patient and transplant characteristics that are correlated with the occurrence of aGVHD, ranged from 0.23 (95% confidence interval (CI) 0.09, 0.63) to 0.83 (CI 0.46, 1.51). A proportional hazards regression analysis, using protein intake as a time-dependent covariate, confirmed these results. The findings of this study provide no support for the hypothesis that intake of protein-containing foods during the first 3 weeks after marrow transplantation increases the risk of aGVHD.

Administration, Oral↗
PubMed1991

An overview: are mentally ill people really more dangerous?

An overview is presented of the research about mental illness and criminality. The findings were confusing and conflicting, mainly because of methodological problems in the research. However, general conclusions included the following: psychiatric patients tended to get arrested at a higher rate; factors associated with offenses by mentally ill people were the same as those associated with offenses by members of the general public; there was no uniform rate of offending, and the high rate of offenders may not be comparable to the majority of patients; the problems experienced were likely a function of the system, with less accessible community resources contributing to a diversion of some mentally ill patients into the criminal justice system.

Criminal Law↗
PubMed1990

Increasing incidence of primary gastric lymphoma.

Both the incidence and mortality rates of gastric cancer have been consistently declining over the past several decades in the United States. In contrast, the incidence of gastric lymphoma may have been increasing during this time. Based on data from the Surveillance, Epidemiology and End Results (SEER) Program, annual incidence rates of gastric lymphoma from 1973 to 1986 were examined. There was a twofold increase in the age-adjusted incidence rates of gastric lymphoma during this time. This increase occurred in both men and women but was limited to people over 60 years of age. Although the reasons for this increase are unknown, the authors speculate that this may be a true increase since neither differences in SEER coding practices nor changes in diagnostic procedures could explain these observations.

Abdomen↗
PubMed1990

Hippocampal synaptic plasticity and NMDA receptors: a role in information storage?

There has recently been renewed interest in the idea that alterations in synaptic efficacy may be the neural basis of information storage. Particular attention has been focused upon long-term potentiation (LTP), a long-lasting, but experimentally induced synaptic change whose physiological properties point to it being a candidate memory mechanism. However, considerations of storage capacity and the possibility of concomitant activity-dependent synaptic depression make it unlikely that individual learning experiences will give rise to gross changes in field potentials similar to those that occur in LTP, even if learning and LTP utilize common neural mechanisms. One way of investigating the functional significance of LTP is to use selective antagonists of those excitatory amino acid receptors whose activation is essential for its induction. This paper discusses various design requirements for such experiments and reviews work indicating that the N-methyl-D-aspartate receptor antagonist AP5 causes a behaviourally selective learning impairment having certain common features to the behavioural profile seen after hippocampal lesions. Two new studies are described whose results show that AP5 has no effect upon the retrieval of previously established memories, and that the dose-response profile of the impairment of spatial learning occurs across a range of extracellular concentrations in hippocampus for which receptor selectivity exists. These experiments show that activation of NMDA receptors is essential for certain kinds of learning.

Animals↗
PubMed1990

Risk of pancreatic cancer in relation to medical history and the use of tobacco, alcohol and coffee.

A population-based case-control study was conducted to examine the relationship between certain medical conditions, the use of tobacco, alcohol and coffee, and the incidence of pancreatic cancer. Cases (N = 148) were married men ages 20 through 74 years diagnosed with pancreatic cancer from July 1982 through June 1986. Controls (N = 188) were identified by random digit dialing. Wives, responding as surrogates for both cases and controls, were interviewed by telephone and completed, alone, a food frequency questionnaire. The risk of pancreatic cancer was increased in individuals with a history of diabetes or pancreatitis, and decreased in those with a history of tonsillectomy. Individuals who had ever smoked cigarettes were at elevated risk of disease. This excess risk was confined to current smokers, in whom the odds ratio was 3.2 (95% CI 1.8-5.7); the risk among former smokers resembled that in those who had never smoked. There was no excess risk of pancreatic cancer among those who had ever used other forms of tobacco, including pipe tobacco, cigars and chewing tobacco. After adjustment for demographic and dietary characteristics, there was no association between pancreatic cancer risk and the intake of coffee, beer, red wine, hard liquor or all alcohol combined; a slight reduction in risk was seen among those consuming white wine daily.

Adult↗
PubMed1990

Alterations of gene expression in human colorectal cancer. Biological implications.

Alterations in gene expression associated with colorectal cancer have been difficult to study because mucosal cell progenitors are not available in culture. We therefore examined specific genes in approximately 100 human colon cancer cell lines using complementary DNA probes and found profound alterations and heterogenity of gene expression in human colorectal carcinoma. Our data imply that understanding human colorectal cancer will not be accomplished by studying one or two oncogenes in a limited number of cell lines or fresh human tissue. More appropriate postulates of transformation to dictate experimental design may include the investigation of proposed three-dimensional structural changes of interface chromatin or other generalized structural relationships that could predispose to an aberrant gene expression program during transformation. Furthermore, focusing on mechanisms of initiation and defining the molecular genetic markers of gastrointestinal mucosal initiation should lead to a more focused set of genetic, rather than epigenetic, mechanisms that underlie oncogenic transformation.

Blotting, Northern↗