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Biomedical subjects

R J Anderson

Publications and source records attributed to R J Anderson.

At least 199 records · Page 11Linked to original sources
PubMed1990

Routes of protein secretion in the isolated perfused cat pancreas.

The routes by which secretory proteins leave the pancreas have been studied during single-pass perfusion of the isolated cat pancreas with a physiological salt solution. The amounts of amylase and total protein appearing in pancreatic juice, venous effluent, and the exudate escaping from the surface of the gland (probably representing lymph) were measured during stimulation with secretin alone and together with bolus injections of acetylcholine. During stimulation with secretin alone, the amylase output in venous effluent was four times greater than in pancreatic juice or exudate. In contrast, most protein appeared in exudate, some in the venous effluent, and a very small amount in pancreatic juice. Acetylcholine transiently increased the output of both amylase and total protein in pancreatic juice to values that greatly exceeded those in venous effluent and exudate. After a delay of 10 min, it also increased the output of amylase and total protein in exudate, but had no effect on venous effluent. In conclusion, secretory proteins enter the venous circulation at a constant rate (i.e., not influenced by acetylcholine stimulation). Some also appear in exudate (lymph), the proportion of which is determined by stimulation. Whether the proteins in these two fluids and in pancreatic juice are derived from the same intracellular pool remains to be determined.

Acetylcholine↗
PubMed1990

Alcohol consumption and problem drinking in Vietnam era veterans and nonveterans.

The relationship between Vietnam era veteran status and 13 indicators of alcohol consumption and problem drinking is examined using data from the 1977, 1983 and 1985 National Health Interview Surveys conducted by the National Center for Health Statistics. Compared to a group of nonveterans frequency matched on age, a greater proportion of Vietnam era veterans are currently heavy drinkers and a smaller proportion are abstainers, after simultaneous adjustment for seven demographic factors (age, region of the U.S., urbanization, ethnicity, marital status, education and income). Further, both white veterans and white nonveterans demonstrate an effect of increasing abstention with increasing age across the 3 interview years. In all race and veteran groups the proportion of lifetime abstainers can be ranked in increasing order as follows: white veterans, white nonveterans, non-white veterans and non-white nonveterans. This ranking is reversed for lifetime heavy drinking. Nearly half of the white veterans report drinking heavily at some point in their lives. Among both whites and non-whites, a significantly greater proportion of veterans than nonveterans report alcohol-related motor vehicle crashes or violations.

Accidents, Traffic↗
PubMed1990

John Humphreys.

Explore the source record for details and available documents.

England↗
PubMed1990

Reduced dependency on arteriography for penetrating extremity trauma: influence of wound location and noninvasive vascular studies.

Indications for arteriography in penetrating extremity trauma remain controversial. We reviewed our clinical experience in 454 patients (514 extremities) with penetrating trauma admitted during a prior 3 1/2-year period. Injuries were caused by stab wounds in 60 (11.7%) extremities and by gunshot wounds in 454 (88.3%) extremities. Thirty-three of the 60 stab wounds (55%) required urgent exploration, and 27 underwent arteriography. No arteriograms were positive for unsuspected arterial injury in this group. Forty-two of 454 gunshot wounds (9.3%) underwent mandatory exploration; arteriograms were performed on 412 extremities. Forty-four arteriograms (10.7%) demonstrated evidence of unsuspected arterial injuries. During the last year, randomly selected extremities (n = 23) have been studied with B-mode ultrasonography and segmental Doppler pressure measurements. Using the subsequent arteriography as the "gold" standard, sensitivity was 83% and specificity was 100%. Gunshot wounds were categorized according to location and positive arteriograms. Injuries to the lateral thigh and arm resulted in no positive arteriograms, while positive studies were observed in 11% of medial and posterior arm, 14% of antecubital fossa, 25% of forearm, 7.5% of medial and posterior thigh, 8% of popliteal fossa, and 26% of calf injuries. We recommend arteriography for gunshot injuries to identified high-risk areas, while clinical evaluation alone is accurate in all stab wounds to the extremities and gunshot wounds to the lateral thigh and outer arm. Preliminary data suggest expanded use of B-mode ultrasonography may further reduce our dependency on arteriography in these cases.

Adolescent↗
PubMed1990

Penetrating extremity trauma: identification of patients at high-risk requiring arteriography.

Indications for arteriography in patients with penetrating trauma to the extremities remain controversial. Some clinicians have recommended universal use of arteriography, whereas others prefer to rely on physical findings alone. To better define our indications for contrast studies, we reviewed clinical data on 306 patients (349 extremities) with penetrating trauma who were admitted during a prior 2-year period (1985 to 1987). Injuries were caused by stab wounds in 50 (14.3%) extremities and by gunshot wounds in 299 (85.7%) extremities. Twenty-seven of the 50 stab wounds (54%) required urgent exploration based on physical findings, whereas 23 underwent arteriography. None of these studies showed unsuspected arterial injury. Twenty-nine of 299 gunshot wounds (9.7%) underwent mandatory exploration, and arteriograms were performed on 270 extremities; findings in 30 studies (11.1%) were positive for unsuspected arterial injuries. Gunshot wounds were categorized according to location and number of arteriograms with positive results. Arteriograms of lateral thigh and upper arm injuries resulted in no positive outcomes. Positive study results were recorded in 22.9% of calf injuries, 20% of forearm and antecubital injuries, 9.5% of popliteal fossa injuries, 9.0% of medial and posterior thigh injuries, and 8.3% of medial and posterior upper arm injuries. We recommend arteriography for penetrating injuries to these high-risk areas. However, clinical evaluation alone is accurate for identification of arterial trauma with lateral thigh or upper arm wounds and stab wounds to the extremities.

Adolescent↗
PubMed1990

Report of the Special Task Force to Study Not-for-Profit Hospitals and Unsponsored Charity Care.

Texas not-for-profit hospitals recently received intense scrutiny regarding their involvement in charity-related contributions when Texas Attorney General Jim Mattox formed the Task Force to Study Not-for-Profit Hospitals and Unsponsored Charity Care. This article details the task force's recommendations concerning charity care obligations of Texas not-for-profit hospitals. Setting the stage for these recommendations was a broad definition of charitable services that included costs for delivering services to indigents and for providing community services to fulfill the hospital's charitable, religious, educational, research, or eleemosynary purposes. The task force unanimously agreed that a mandated level of charity care was incongruent with the hospitals' individual missions and specific community needs, but they supported the formation of standard accounting procedures for charitable services and the voluntary submission of their mission statements to the attorney general of Texas. While the hospitals' role in providing charitable services is very important, the task force emphasized that the overall need for adequate financing and reimbursement of health care is a societal problem that needs specific state and federal actions.

Accounting↗
PubMed1990

Rapid estimation of carboxyhemoglobin by breath sampling in an emergency setting.

Breath measurement of carbon monoxide (CO) can be rapidly performed in the emergency department setting by a reliable method that closely approximates carboxyhemoglobin. This method is helpful in the immediate determination of CO exposure for individual patients, but could serve as a valuable triage aid when large groups of patients are suspected of CO exposure. Serial CO determinations can be obtained during oxygen treatment to monitor for improvements without painful needle punctures and needless consumption of professional time and expense.

Adolescent↗
PubMed1989

The changes in dental caries experience of 12-year-old schoolchildren in two Somerset schools. A review after an interval of 25 years.

The examination of 12-year-old children attending schools in central Somerset, where similar examinations were conducted 6, 19 and 25 years previously, has indicated that the caries experience of the children in these schools is continuing to decrease, and at a faster annual rate than previously. The average DMFT was 1.05; it was 5.36, 3.44 and 2.77 25, 19 and 6 years previously. The major reduction over the last 6 years is in the average number of filled teeth per child. The treatment philosophy of the practitioners caring for the children has changed and now appears to be appropriate to the treatment need.

Child↗
PubMed1989

Lysis of Escherichia coli by the bacteriophage phi X174 E protein: inhibition of lysis by heat shock proteins.

Lysis of Escherichia coli by the cloned E protein of bacteriophage phi X174 was more rapid than expected when bacteria were shifted from 30 to 42 degrees C at the time of E induction. Since such treatment also induces the heat shock response, we investigated the effect of heat shock proteins on lysis. An rpoH mutant was more sensitive to lysis by E, but a secondary suppressor mutation restored lysis resistance to parental levels, which suggests that the sigma 32 subunit itself did not directly increase lysis resistance. At 30 degrees C, mutants in five heat shock genes (dnaK, dnaJ, groEL, groES, and grpE) were more sensitive to lysis than were their wild-type parents. The magnitude of lysis sensitivity varied with mutation and strain background, with dnaK, dnaJ, and groES mutants consistently exhibiting the greatest sensitivities. Extended protection against lysis occurred when overproduction of heat shock proteins was induced artificially in cells that contained a plasmid with the rpoH+ gene under control of the tac promoter. This protective effect was completely abolished by mutations in dnaK, dnaJ, or groES but not by grpE or groEL mutations. Altered membrane behavior probably explains the contradiction whereby an actual temperature shift sensitized cells to lysis, but production of heat shock proteins exhibited protective effects. The results demonstrate that E-induced lysis can be divided into two distinct operations which may now be studied separately. They also emphasize a role for heat shock proteins under non-heat-shock conditions and suggest cautious interpretation of lysis phenomena in systems where E protein production is under control of a temperature-sensitive repressor.

Bacterial Proteins↗
PubMed1989

Mechanism of neuropeptide Y inhibition of vasopressin action in rat cortical collecting tubule.

Neuropeptide Y (NPY) is a unique 36-amino acid peptide found in high concentrations in brain and peripheral neurons. Although NPY is present in kidney tissue, its role in regulation of renal function has not been delineated. We found that NPY significantly decreases arginine vasopressin (AVP) but not adenosine 3',5'-cyclic monophosphate (cAMP)-stimulated hydraulic conductivity (Lp) in perfused rat cortical collecting tubules (CCT). Either alpha 2-adrenergic receptor blockade (yohimbine) or occupancy (clonidine) prevent NPY inhibition of AVP-stimulated Lp. By contrast, alpha 1-adrenergic receptor blockade with prazosin did not alter NPY inhibition of AVP action. Pretreatment of CCT with pertussis toxin also abolishes NPY inhibition of AVP-stimulated Lp. These data suggest that NPY acts via an alpha 2-adrenergic receptor coupled to a pertussis toxin-sensitive protein to inhibit AVP-stimulated cAMP formation and Lp in the rat CCT.

Animals↗
PubMed1989

Bradykinin activates protein kinase C in cultured cortical collecting tubular cells.

Bradykinin inhibits vasopressin-stimulated water transport in cortical collecting tubular cells. The biochemical mechanism of this effect was explored by means of primary cultures of rabbit cortical collecting tubular cells. Bradykinin was found to produce a rapid release of calcium from intracellular stores, an increase in sn-1,2-diacylglycerol levels, and a fivefold increase in membrane-bound protein kinase C activity, consistent with stimulation of phospholipase C and activation of protein kinase C in rabbit cortical collecting tubular cells. In addition, bradykinin produced a dose-dependent 46% inhibition of vasopressin-stimulated adenosine 3',5'-cyclic monophosphate (cAMP) formation. Pretreatment with the protein kinase C inhibitors, H-7 and staurosporine, reversed the bradykinin-mediated inhibition of vasopressin-stimulated cAMP accumulation. In contrast, pretreatment with either the phospholipase A2 inhibitor, mepacrine, or pertussis toxin did not prevent the inhibitory effect of bradykinin on vasopressin-stimulated cAMP production, suggesting that the effects are not mediated by prostaglandin E2 or activation of a pertussis-toxin sensitive guanine nucleotide regulatory protein (e.g., Gi). Because bradykinin also inhibits isoproterenol-stimulated cAMP formation but does not inhibit either basal-, forskolin-, or cholera toxin-stimulated cAMP accumulation, the site of this inhibition appears to involve the hormone receptor or coupling of the receptor to the stimulatory guanine nucleotide regulatory subunit (Gs). The results demonstrate that bradykinin stimulates phospholipase C leading to activation of protein kinase C, which then inhibits vasopressin-stimulated cAMP production at the level of the hormone receptor or coupling of the receptor to Gs in cultured cortical collecting tubular cells.

Animals↗
PubMed1989

Alcohol consumption and problem drinking in white male veterans and nonveterans.

The relation between veteran status and 15 indicators of alcohol consumption and problem drinking is examined using data from the 1977, 1983, and 1985 National Health Interview Surveys conducted by the National Center for Health Statistics. After simultaneous adjustment for age, region of the US, urbanization, ethnicity, marital status, education, and income, a greater proportion of White male veterans than White male nonveterans were heavy drinkers and a smaller proportion were abstainers. This association appeared in all three survey years; further, veterans consistently reported a high daily consumption level (the equivalent of approximately six bottles of beer, five glasses of wine, or four mixed drinks) compared to nonveterans. Among White male veterans, 6.9 percent reported family or marital problems and 13.9 percent reported motor vehicle crashes or violations compared to 4.4 percent and 8.9 percent, respectively, among nonveterans. The same pattern was observed for lifetime prevalences of alcoholism (veterans have nearly two and a half times the lifetime prevalence of nonveterans), cirrhosis of the liver, and unspecified alcohol-related problems.

Accidents, Traffic↗
PubMed1989

Identification and evaluation of O-alkyl substituted hydroxamic acids as potent in vitro inhibitors of the hepatic glycine cleavage system and investigation of their action on in vivo central nervous system glycine concentration.

The identification and evaluation of an extensive series of O-alkyl substituted hydroxamic acids as potent in vitro inhibitors of the hepatic glycine cleavage system is described. An investigation of the action of selected examples on the in vitro brain glycine cleavage system and their influence on in vivo plasma and central nervous system glycine concentrations following systemic administration is also reported.

Animals↗