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Biomedical subjects

R Lockwood

Publications and source records attributed to R Lockwood.

At least 19 recordsLinked to original sources

Breeds of dogs involved in fatal human attacks in the United States between 1979 and 1998.

OBJECTIVE: To summarize breeds of dogs involved in fatal human attacks during a 20-year period and to assess policy implications. ANIMALS: Dogs for which breed was reported involved in attacks on humans between 1979 and 1998 that resulted in human dog bite-related fatalities (DBRF). PROCEDURE: Data for human DBRF identified previously for the period of 1979 through 1996 were combined with human DBRF newly identified for 1997 and 1998. Human DBRF were identified by searching news accounts and by use of The Humane Society of the United States' registry databank. RESULTS: During 1997 and 1998, at least 27 people died of dog bite attacks (18 in 1997 and 9 in 1998). At least 25 breeds of dogs have been involved in 238 human DBRF during the past 20 years. Pit bull-type dogs and Rottweilers were involved in more than half of these deaths. Of 227 reports with relevant data, 55 (24%) human deaths involved unrestrained dogs off their owners' property, 133 (58%) involved unrestrained dogs on their owners' property, 38 (17%) involved restrained dogs on their owners' property, and 1 (< 1%) involved a restrained dog off its owner's property. CONCLUSIONS: Although fatal attacks on humans appear to be a breed-specific problem (pit bull-type dogs and Rottweilers), other breeds may bite and cause fatalities at higher rates. Because of difficulties inherent in determining a dog's breed with certainty, enforcement of breed-specific ordinances raises constitutional and practical issues. Fatal attacks represent a small proportion of dog bite injuries to humans and, therefore, should not be the primary factor driving public policy concerning dangerous dogs. Many practical alternatives to breed-specific ordinances exist and hold promise for prevention of dog bites.

Animals↗

Fatal dog attacks, 1989-1994.

OBJECTIVES: To update data on fatal dog bites and see if past trends have continued. DESIGN: To merge data from vital records, the Humane Society of the United States, and searches of electronic news files. SETTING: United States. SUBJECTS: U.S. residents dying in the U.S. from 1989 through 1994 from dog bites. RESULTS: We identified 109 dog bite-related fatalities, of which 57% were less than 10 years of age. The death rate for neonates was two orders of magnitude higher than for adults and the rate for children one order of magnitude higher. Of classifiable deaths, 22% involved an unrestrained dog off the owner's property, 18% involved a restrained dog on the owner's property, and 59% involved an unrestrained dog on the owner's property. Eleven attacks involved a sleeping infant; 19 dogs involved in fatal attacks had a prior history of aggression; and 19 of 20 classifiable deaths involved an unneutered dog. Pit bulls, the most commonly reported breed, were involved in 24 deaths; the next most commonly reported breeds were rottweilers (16) and German shepherds (10). CONCLUSIONS: The dog bite problem should be reconceptualized as a largely preventable epidemic. Breed-specific approaches to the control of dog bites do not address the issue that many breeds are involved in the problem and that most of the factors contributing to dog bites are related to the level of responsibility exercised by dog owners. To prevent dog bite-related deaths and injuries, we recommend public education about responsible dog ownership and dog bite prevention, stronger animal control laws, better resources for enforcement of these laws, and better reporting of bites. Anticipatory guidance by pediatric health care providers should address dog bite prevention.

Adolescent↗

Tryptophan metabolites, pyridoxine (vitamin B6) and their influence on the recurrence rate of superficial bladder cancer. Results of a prospective, randomised phase III study performed by the EORTC GU Group. EORTC Genito-Urinary Tract Cancer Cooperative Group.

This double-blind randomised phase III trial was designed to assess the effect of pyridoxine administration on the recurrence of Ta and T1 transitional cell tumours of the bladder. The trial accrued 291 patients and showed no significant difference between the pyridoxine and placebo treatment groups with respect to the time to first recurrence or the recurrence rate. Adjustment for the main prognostic factors, namely the recurrence rate prior to entry, the number of tumours at entry, the G grade and the levels of the tryptophan metabolites kynurenine plus acetyl kynurenine at entry do not change the overall conclusions.

Administration, Oral↗

The role of animals in our perception of people.

Objective evidence is beginning to confirm the popular belief that people are often judged by the way they interact with animals. This phenomenon is reviewed in the context of social and cognitive psychology and suggestions are offered for future research.

Animals↗

Comparative inhibition of nuclear RNA synthesis in cultured mouse leukemia L1210 cells by adriamycin and 4'-epi-adriamycin.

Adriamycin and 4'-epi-adriamycin were compared as to their effect on nRNA synthesis. 4'-Epi-adriamycin was a more effective inhibitor than the parent compound of RNA synthesis as measured by incorporation of [3H]-uridine. Adriamycin inhibited all three species of nRNA (ribosomal, non-poly(A)hnRNA, poly(A)hnRNA) to approximately the same extent. 4'-Epi-adriamycin on the other hand inhibited the nRNA species in the following order: non-poly(A)hnRNA greater than ribosomal RNA greater than poly(A)hnRNA. The inhibitory effects of both drugs on incorporation of uridine into RNA were reversible at low concentrations (5 microgram/ml).

Animals↗

Differentiation of metabolic adrenoceptors.

1 Cardiovascular and metabolic responses to intravenous infusion of isoprenaline were measured in fasted, anaesthetized cats. 2 Isoprenaline (0.2 mug kg-1 min-1 for 15 min) decreased diastolic blood pressure and increased heart rate, blood glucose, blood lactate and plasma free fatty acids. 3 Oxprenolol (0.5 mg/kg) antagonized all cardiovascular and metabolic effects of isoprenaline non-selectively. 4 Para-oxprenolol (0.25 mg/kg) and practolol (4 mg/kg) antagonized the effects of isoprenaline on heart rate and free fatty acids selectively. 5 H 35/25 ((I-(4-methylphenyl)-2-isopropyl aminopropanol) hydrochloride, 3 mg/kg) antagonized the effects of isoprenaline on blood pressure, glucose and lactate selectively. 6 It is concluded that metabolic adrenoceptors are differentiated into subtypes similar to those mediating cardiostimulation and vasodilatation.

Adrenergic beta-Antagonists↗

Selective activation of cardiovascular adenylate cyclase in vivo.

Cyclic AMP levels were measured in cardiac and vascular tissues removed from pentobarbitone-anesthetized rats pretreated with theophylline 45 mg/kg i.p. Noradrenaline, 20 microng/kg i.v., increased cardiac but not vascular cyclic AMP levels; this selective effect of noradrenaline was not altered by pretreatment with phenoxybenzamine, 1 mg/kg i.v. Tazolol, 120 microng/kg i.v., selectively increased cardiac cyclic AMP levels whereas fenoterol, 15 microng/kg i.v., selectively increased vascular cyclic AMP levels. The results suggest that adenylate cyclase activation in cardiac and vascular tissued in vivo is mediated by beta adrenoceptors which consist of different subtypes.

Adenylyl Cyclases↗

Distribution of renal blood flow in dogs with congestive heart failure.

Studies were performed to determine whether the intrarenal distribution of cortical blood flow is altered in congestive heart failure. Utilizing the radioactive microsphere method, we studied eight dogs that developed congestive heart failure secondary to the construction of an aortocaval fistula. They had marked reduction in total renal blood flow not accompanied by intracortical redistribution of blood flow. All dogs had developed edema and/or ascites, and gained a mean of 3.4 kg; glomerular filtration rate, hematocrit, and urinary sodium excretion fell significantly. Renal vascular resistance increased; mean blood pressure and filtration fraction were unchanged. Furosemide was administered to a second group of nine fistula dogs. The drug produced a marked natriuresis associated with a decrease in outer cortical blood flow (zone 1) and an increase in midcortical zones 2 and 3; no change was observed in zone 4. We conclude: 1) chronic salt retention occurs in high-output heart failure in the absence of redistribution of renal cortical blood flow, and 2) the effect of furosemide on intrarenal hemodynamics of dogs with heart failure is similar to that seen in normal animals.

Animals↗

Glucose and bicarbonate reabsorption in edematous dogs.

Glucose and bicarbonate reabsorption were studied in dogs made edematour by aortocaval fistula (A-V dogs) and in sham-operated dogs. Following construction of the A-V fistula, there was a significant increase in body weight; glomerular filtration rate, renal plasma flow, hematocrit, and sodium excretion decreased significantly. Bicarbonate reabosorption was significantly higher in A-V than in sham dogs both during control and volume expansion. Volume expansion depressed bicarbonate reabsorption significantly in both groups. Glucose reabsorption fell following volume expansion in both groups; glucose reabsorption was significantly higher in A-V dogs than in sham dogs during control and volume expansion. Volume expansion led to a minimal increase in sodium excretion in A-V dogs when compared to the increase in the sham dogs. These data demonsttate that chronic sodium retention is associated with enhanced reabsorption of glucose and bicarbonate. The site in the neophron responsible for the increase in reabsorption of these substances cannot be determined with certainty based on these clearance studies although it is possible that proximal reabsorption may be enhanced in this model.

Acid-Base Equilibrium↗