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Biomedical subjects

A Franklin

Publications and source records attributed to A Franklin.

At least 19 recordsLinked to original sources
PubMed1998

Doing it all in the public eye: a comparative analysis of California district hospital affiliations.

California contains 74 hospital districts, which are local governmental entities with publicly elected boards. Historically, they have been responsible for operating hospitals in remote areas to provide for the health care needs of their communities. Because the health care market has become increasingly competitive and because some of these once rural areas have grown into large cities, these districts are seeking partners for their hospitals in hopes of preserving their long-term financial viability. The terms reached in these transactions are discussed in the article.

California↗
PubMed1997

[Animal husbandry and food handling today. Current food preservation has changed the intestinal flora].

In the modern world, as refrigerated storage has replaced lactic acid fermentation methods of food preservation, we no longer ingest large quantities of live lactobacilli with our food, but relatively large numbers of potentially pathogenic Gram-negative bacteria instead. In the brave new world, antibiotics are used as growth-promoting additives in animal feed in every country but Sweden. The antibiotics used in Europe at low dosages, and exempt from prescription requirements, include macrolides, streptogramins and nitro-imidazoles. There is reason to believe that avoparcin, recently banned in Europe as an antibiotic animal feed additive, has contributed to the occurrence of vancomycin-resistant enterococci in humans. Animal foodstuffs production in Europe and the USA is so intensive that it provides very favourable conditions for the spread of bacteria. Pig, cattle and poultry breeding in Europe are beset by formidable difficulties in the form of Salmonella infections, which constitute not only a hygiene but also a clinical problem. Sweden, the bravest of brave new worlds, faces an increase in the influx of domestic animals and foodstuffs from other countries, and in general less restrictive regulations concerning food production and animal husbandry, but reduced powers of control. Thus, we may expect problems both with pathogens (traditional ones such as Salmonella, and potential ones such as food-spoilage Gram-negative bacteria), and with antibiotic-resistant bacteria in our food-stuffs, to become greater.

Animal Husbandry↗
PubMed1997

Effects of magnesium cardioplegia on regulation of the porcine coronary circulation.

We compared the effect of hypermagnesium and hyperkalemic crystalloid cardioplegia on beta-adrenoceptor-mediated and endothelium-dependent relaxation and myogenic responses of coronary arterioles. Pigs were placed on cardiopulmonary bypass. Hearts were arrested with cold hypermagnesium (25 mM Mg2+, hyper-Mg, n = 12) or hyperkalemic (25 mM K+, hyper-K, n = 12) crystalloid cardioplegia for 1 hr. Hearts of selected pigs (n = 6 in each group) were then reperfused for 1 hr. In vitro relaxation responses of acetylcholine-pre-contracted arterioles were studied in a pressurized no-flow state with video-microscopy. Relaxation of pre-contracted coronary microvessels (70-150 microns) to isoproterenol (beta-adrenergic agonist) and forskolin (adenylate cyclase activator) was preserved after cardioplegia using a hyper-Mg solution. In contrast, responses were impaired to isoproterenol [P < 0.01 (two-factor ANOVA) vs. controls, n = 6] and forskolin (P < 0.01) after hyper-K cardioplegia. After 1 hr of reperfusion, relaxation responses to isoproterenol and forskolin were partially recovered. Hyper-Mg cardioplegia and post-cardioplegic reperfusion did not affect receptor-mediated endothelium-dependent relaxation to ADP, non-receptor-mediated endothelium-dependent relaxation to A23187, and endothelium-independent relaxation to nitroprusside. However, responses to ADP (P < 0.01) and A23187 (P < 0.05) were selectively impaired after hyper-K cardioplegia. Myogenic contraction was impaired after either hyper-Mg or hyper-K cardioplegia. Left ventricular systolic pressure, coronary blood flow, and +dP/dt were similar after hyper-Mg or hyper-K cardioplegia. These results suggest that hyper-Mg cardioplegia is superior to hyper-K cardioplegia in terms of preserving beta-adrenoceptor-mediated and endothelium-dependent regulation of the coronary microcirculation, yet it has minimal if any additional beneficial effect on preserving myogenic responses or myocardial contractile function.

Adrenergic beta-Agonists↗
PubMed1997

Comparative effects of continuous warm blood and intermittent cold blood cardioplegia on coronary reactivity.

BACKGROUND: Cardioplegia is known to affect coronary vascular reactivity. We examined the effects of intermittent cold and continuous warm blood cardioplegia on beta-adrenoceptor-mediated, adenosine triphosphate-sensitive K+ (K+ATP)-channel-mediated, and endothelium-dependent relaxation and on the myogenic tone of coronary arterioles. METHODS: Pigs were placed on cardiopulmonary bypass. Hearts were arrested for 1 hour with a cold blood cardioplegic solution administered intermittently (n = 12; iCB-CP) or with a warm blood cardioplegic solution delivered continuously (n = 12; cWB-CP). Selected hearts (n = 6 in each group) were then reperfused for 1 hour. In vitro relaxation responses of precontracted microvessels (50 to 160 microns) were studied in a pressurized no-flow state. RESULTS: Relaxation in response to isoproterenol (beta-adrenergic agonist) was similar after iCB-CP and cWB-CP, whereas forskolin (adenylate cyclase activator)-induced relaxation was impaired more after iCB-CP than after cWB-CP. After reperfusion the respective responses were similar. Both iCB-CP and cWB-CP preserved receptor-mediated, endothelium-dependent relaxation in response to adenosine, 5'-diphosphate; non-receptor-mediated endothelium-dependent relaxation in response to A23187; endothelium-independent cyclic guanosine monophosphate-mediated relaxation in response to sodium nitroprusside, and K+ATP-channel-mediated relaxation. Relaxations in response to 8-bromo-cyclic guanosine monophosphate (a cyclic guanosine monophosphate-dependent protein kinase activator) and to 8-bromo-cyclic adenosine monophosphate (a cyclic adenosine monophosphate-dependent protein kinase activator) were impaired after iCB-CP alone and after reperfusion, whereas the respective responses were not affected after cWB-CP. Myogenic tone was decreased similarly after iCB-CP and cWB-CP but was not further altered after reperfusion. Cardiac function was similar after iCB-CP and cWB-CP. CONCLUSIONS: These results suggest that cWB-CP is similar to iCB-CP in its ability to preserve endothelium-dependent relaxation and K+ATP-channel function. The superior preservation of beta-adrenergic-cyclic adenosine monophosphate-mediated coronary responses after cWB-CP is brief and associated with minimal improvement of myocardial function and myogenic tone.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1997

Pharmacokinetics of penicillin-G in ewes and cows in late pregnancy and in early lactation.

Concentrations of penicillin-G in serum were determined after single intravenous doses of potassium penicillin-G (10 mg/kg body wt) to ewes and cows in late pregnancy and in early lactation. Penicillin-G in serum was analysed by a microbiological method and pharmacokinetic parameters were calculated by model-independent methods. Serum concentrations were lower in early lactation than in late pregnancy in both ewes and cows. The differences were statistically significant at most sampling times in ewes but only during the first hour in cows. Weight corrected values of clearance and volume of distribution were significantly higher in early lactation than in late pregnancy in both ewes and cows. Mean residence time and elimination-half life were shorter in lactating than in pregnant ewes, however for the latter parameter the difference was not statistically significant. Neither of these parameters changed in cows. It is concluded that in both ewes and cows pharmacokinetic parameters of penicillin-G are altered from late pregnancy to early lactation but that these changes have little practical impact and do not call for a revised dosage regime of the studied drug.

Animals↗
PubMed1997

Outcome of African American men screened for prostate cancer: the Detroit Education and Early Detection Study.

PURPOSE: Will early detection impact on stage of disease and recurrence of prostate cancer in a high risk population? We initiated a community based study to educate and recruit African American men for early diagnosis of prostate cancer, that is the Detroit Education and Early Detection (DEED) study. Our objective was to evaluate our recruitment process for this target population, examine the percentage of organ confined prostate cancer in men undergoing radical prostatectomy and measure recurrence biochemically. MATERIALS AND METHODS: A community based study from February 1993 to February 1995 through the African American churches in metropolitan Detroit was initiated. We compared the early detection group treated with radical prostatectomy to the population presenting to our urological clinic during the same period. We tested and followed 1,105 African American men using the prostate specific antigen blood test. RESULTS: Pathologically organ confined prostate cancer was diagnosed in 11 of 17 men (65%) who underwent radical prostatectomy in the DEED project. Within the clinic population 35% of the African American men were diagnosed with pathologically organ confined prostate cancer. The difference between the 2 populations was statistically significant (p = 0.033). Disease recurred in 1 of 15 (7%) and 39 of 157 (25%) men in the DEED and clinic populations, respectively (p = 0.97). CONCLUSIONS: We demonstrated our ability to recruit African American men into a prostate cancer early detection program. We diagnosed early but clinically significant prostate cancers among African American men with characteristics similar to prostate cancers diagnosed in other early detection studies in which the overwhelming majority of men were white.

Aged↗
PubMed1996

Usage of antibacterial and antiparasitic drugs in animals in Sweden between 1988 and 1993.

The total usage of antibacterial and antiparasitic drugs in animals in Sweden between 1988 and 1993 was assessed. The data for the antibacterial drugs were divided among the different classes of drug used each year. Special attention was paid to the use of antibacterial drugs in feeding stuffs and to their use in pigs and fish. During the period studied, the total usage of antibacterial drugs remained stable at approximately 35 tonnes of active substance annually. The use of antibacterial drugs for growth-promoting purposes was prohibited in Sweden in 1986 and became available by veterinary prescription only. As a result the total amount used annually has decreased and stabilised at a level about 35 per cent lower than before the ban. Important changes during 1988 to 1993 were a doubled usage of tetracyclines and a 50 per cent decrease in the use of olaquindox. The five major classes of antibacterial drugs used in 1993 were benzyl penicillin (13.2 tonnes), tetracyclines (8.8 tonnes), olaquindox (3.5 tonnes), sulphonamides (2.0 tonnes) and aminoglycosides (1.9 tonnes). The total annual usage of coccidiostatic drugs, mainly used in the poultry industry, was stable at approximately 10 tonnes, while the usage of other antiparasitic drugs increased slightly to 7.7 tonnes.

Aminoglycosides↗
PubMed1995

Myogenic reactivity of coronary resistance arteries after cardiopulmonary bypass and hyperkalemic cardioplegia.

BACKGROUND: Cardiopulmonary bypass (CPB) and cardioplegia are associated with systemic hypotension and altered vascular responses, suggesting a defect in the smooth muscle control of vascular tone. Previous studies demonstrated alteration in neurohumoral control of the systemic and coronary circulation after CPB and cardioplegia; however, effects of CPB and cardioplegia on the intrinsic control of the vascular smooth muscle, especially in the coronary microcirculation, remain to be determined. METHODS AND RESULTS: Pigs were placed on CPB. Selected hearts were arrested with a cold, hyperkalemic ([K+] = 25 mmol/L) crystalloid cardioplegic solution for 1 hour. In another group, hearts were arrested and then reperfused with warm blood for 1 hour. Coronary arterioles (70 to 149 microns) were studied in a pressurized, no-flow state with video microscopy. Myogenic reactivity was examined to stepwise increases in intraluminal pressure from 10 to 100 mm Hg. The vessel diameter was normalized to the diameter at 50 mm Hg after application of papaverine (10(-4) mol/L). Myogenic reactivity of vessels from noninstrumented control pigs was not altered after mechanical denudation of the endothelium or pretreatment with NG-nitro-L-arginine or indomethacin. In vessels from control pigs and vessels from the CPB group, myogenic contraction was observed with pressures > 40 mm Hg. However, CPB significantly decreased intrinsic tone as the pressure-diameter relation shifted upward (P < .05 versus control). This decreased intrinsic tone was markedly attenuated by NG-nitro-L-arginine, suggesting an increased basal release of nitric oxide. Cardioplegic arrest, with or without reperfusion, decreased myogenic contraction to pressures > 40 mm Hg (P < .05 versus control). Pretreatment of vessels with glybenclamide normalized the cardioplegia-induced decrease in myogenic contraction (P < .05), suggesting that the reduced myogenic contraction is due to activation of ATP-sensitive potassium channels. CONCLUSIONS: The result of the present study suggests that coronary microvascular myogenic reactivity and the intrinsic tone are reduced after hyperkalemic cardioplegia and that CPB preserves myogenic reactivity but reduces the intrinsic tone of the vascular smooth muscle.

Animals↗
PubMed1995

Dating and context of three middle stone age sites with bone points in the Upper Semliki Valley, Zaire.

The extent to which the earliest anatomically modern humans in Africa exhibited behavioral and cognitive traits typical of Homo sapiens sapiens is controversial. In eastern Zaire, archaeological sites with bone points have yielded dates older than 89(-15)+22 thousand years ago by several techniques. These include electron spin resonance, thermoluminescence, optically stimulated luminescence, uranium series, and amino acid racemization. Faunal and stratigraphic data are consistent with this age.

Animals↗
PubMed1995

Pulmonary injury after total or partial cardiopulmonary bypass with thromboxane synthesis inhibition.

Previous studies have shown an increase in left atrial plasma thromboxane (TBX) level and associated increase in lung injury parameters after total cardiopulmonary bypass (t-CPB) but not after partial cardiopulmonary bypass (p-CPB). We used dazmegrel to study the effect of TBX synthesis inhibition on lung injury after t-CPB compared with p-CPB. Sheep were placed on t-CPB without ventilation and with pulmonary artery occlusion (n = 7) or p-CPB with ventilation and an unrestricted pulmonary artery (n = 7). All sheep were treated with dazmegrel. After 90 minutes we separated the sheep from CPB. Plasma TBX, platelets, white blood cells, protein concentration, lung lymph protein, flow, and pulmonary vascular resistance were measured before and after CPB. Lung biopsies were also obtained. Minimal derangement of these pulmonary parameters was seen after either p-CPB or t-CPB. Inhibition of TBX synthesis virtually eliminated the lung injury previously reported after t-CPB, when compared with p-CPB. Clearly TBX has an important role in mediating lung injury after t-CPB.

Animals↗
PubMed1994

Acidemia and hypernatremia enhance postischemic recovery of excitation-contraction coupling.

The purpose of the present study was to determine whether Na(+)-H+ and Na(+)-Ca2+ exchanges modulate postischemic recovery of excitation-contraction coupling. Experiments were performed in 43 isolated isovolumic dog hearts perfused with blood (pH 7.40, 141 mmol/L Na+, 34 degrees C, paced at 2 Hz). A 3 x 3-mm region at the left ventricular (LV) apex was loaded with aequorin for monitoring [Ca2+]i simultaneously with LV pressure. No-flow ischemia for 2 to 3 minutes was followed by 20 minutes of aerobic reperfusion with (1) unmodified control blood (141 mmol/L Na+, pH 7.40), (2) acidemic blood (141 mmol/L Na+, pH 6.60, at 0 to 3 minutes of reperfusion), (3) hypernatremic blood (149 or 157 mmol/L Na+, pH 7.40, at 0 to 20 minutes of reperfusion), or (4) hyperosmotic blood (141 mmol/L Na+ + 30 mmol/L mannitol, pH 7.40, at 0 to 20 minutes of reperfusion). Reperfusion with unmodified control blood was immediately followed by an increase in [Ca2+]i and LV systolic and diastolic pressure that persisted for 2 to 3 minutes before returning to or below baseline. Ventricular arrhythmia occurred during this period (> 80%). This transient increase of [Ca2+]i was attenuated by acidemic or hypernatremic perfusate. With acidemic or hypernatremic reperfusion, recovery of LV developed pressure at 20 minutes was more complete than with unmodified control reperfusion: acidemic blood (n = 7), 93 +/- 3% (P < .01); hypernatremic blood (149 mmol/L Na+, n = 7), 89 +/- 2% (P < .02); hypernatremic blood (157 mmol/L Na+, n = 4), 91 +/- 2% (P < .01); and unmodified control blood (n = 17), 80 +/- 2%. With hyperosmotic reperfusion, recovery of LV developed pressure at 20 minutes was not improved (82 +/- 3%). From these results we conclude that (1) an increase in intracellular Ca2+ occurs transiently after no-flow ischemia and may cause arrhythmia and decreased Ca2+ responsiveness of the contractile elements, (2) acidemic and hypernatremic reperfusion ameliorates postischemic dysfunction by preventing the increase in intracellular Ca2+, suggesting that (3) Na(+)-H+ and Na(+)-Ca2+ exchange may play important modulatory roles during reperfusion.

Animals↗
PubMed1994

Evaluation of a cow-side test for detection of gram-negative bacteria in milk from cows with mastitis.

A modified Limulus amebocyte lysate (LAL) cow-side test was evaluated under field conditions. The principle of the test is to visualize reactions between test components and endotoxin from the cell wall of Gram-negative bacteria. The practical purpose is to detect such bacteria in mastitic milk. Secretions from 789 udder quarters with clinical mastitis were examined by the LAL-test. Parallel quarter milk samples were sent to a mastitis laboratory of microbiological examination. Eleven veterinary surgeons in three veterinary districts in Norway performed the field investigations. Results of the LAL-test and culture agreed in 93% of all milk samples tested, agreement measured by kappa being 0.63. The sensitivity of the test in detecting Gram-negative bacteria was 63%, while the specificity was 97%. The predictive value of a positive test result was 70%, the figure being somewhat higher (75%) when the material was limited to milk samples without antibiotic residues. The predictive value of a negative test result was 95%. The LAL-test is considered to constitute a valuable cow-side test for the veterinary practitioner, aiding the selection of antibacterial drug of choice for the initial treatment of clinical mastitis.

Animals↗
PubMed1993

Accidental injection of white spirit into the hand in golfers.

We report two cases in which white spirit has been injected accidentally into the hand by golfers, while attempting to remove the grip of the golf-club handle in order to replace it. One of our patients has anecdotal evidence of this happening in at least two other cases, one of which resulted in amputation of the index finger, and the other in severe damage to the thumb.

Accidents↗
PubMed1992

Spread of a newly found trimethoprim resistance gene, dhfrIX, among porcine isolates and human pathogens.

A plasmid-borne gene mediating trimethoprim resistance, dhfrIX, newly found among porcine strains of Escherichia coli, was observed at a frequency of 11% among trimethoprim-resistant veterinary isolates. This rather high frequency of dhfrIX could be due to the extensive use of trimethoprim in veterinary practice in Sweden. After searching several hundred clinical isolates, one human E. coli strain was also found to harbor the dhfrIX gene. Thus, the dhfrIX gene seems to have spread from porcine bacteria to human pathogens. Furthermore, the occurrence of other genes coding for resistant dihydrofolate reductase enzymes (dhfrI, dhfrII, dhfrV, dhfrVII, and dhfrVIII) among the porcine isolates was investigated. In addition, association of dhfr genes with the integraselike open reading frames of transposons Tn7 and Tn21 was studied. In colony hybridization experiments, both dhfrI and dhfrII were found associated with these integrase genes. The most common combination was dhfrI and int-Tn7, indicating a high prevalence of Tn7.

Animals↗
PubMed1992

Mechanical assistance of the left ventricle: acute effect on cardiac performance and coronary flow of different perfusion patterns.

Mechanical circulatory assistance by ventricular assist devices provides an opportunity to influence the aortic pressure pattern, which may affect ventricular loading and coronary perfusion. The effect of synchronous, pulsatile coronary perfusion of an assist device-supported left ventricle has not been studied. To analyze the effect of different perfusion patterns on left ventricular performance and on coronary flow, independent of pressure and volume loading, we used three different modes of aortic perfusion in an isometric, contracting, isolated canine heart model. The effect of nonpulsatile, counter-pulsatile, and copulsatile coronary perfusion was analyzed in four subgroups to simulate different, clinically relevant situations (using two different ventricular end-diastolic volumes [normal and high] and two mean perfusion pressures [normal and critically low]). Our experiments demonstrated that total coronary flow is optimized by making the perfusion pressure pulsatile and by synchronously timing the pump systole with ventricular diastole (counterpulsation). Under identical conditions of preload and mean perfusion pressure, coronary flow and left ventricular contractility were decreased during non-pulsatile and copulsatile aortic perfusion when compared with counterpulsatile flow. There were no significant differences between the nonpulsatile and copulsatile modes. We conclude from these data that a nonejecting, but contracting, left ventricle will have improved systolic function and coronary blood flow if the coronary perfusion pressure is synchronized in a counterpulsatile manner. This is a significant implication for mechanical left ventricular assist devices when used to promote myocardial recovery.

Animals↗