Rats were exposed to three cigarettes per day for 35 days, under realistic conditions. Pulmonary glucose-6-phosphate dehydrogenase (G-6-PD) activity in the exposed animals increased 27% over control values (P less than .05). Subsequent exposure to acute, high-dose ozone (3 ppm for 4 hr) decreased the augmented G-6-PD activities to near normal levels, whereas ozone exposures in animals not exposed to cigarette smoke caused mild decreases in pulmonary G-6-PD activities. The importance of these findings with respect to the susceptibility of the smoker to oxidant exposures is unknown.

Animals↗

PubMedDate not supplied

Q fever hazards from sheep and goats used in research.

Two recent outbreaks of Q fever in research institutions prompted the authors to review extant data, in an effort to delineate hazards to humans from small ruminants used in research. Prevalence of Q fever antibodies was 24% among 2097 sheep and 57% among 1475 goats from various sources. In a facility using sheep for prenatal research, in which an epidemic of human Q fever later occurred, antibody prevalence among sheep was 77%, with larger than usual proportions of high (greater than or equal to 128) titers. Antibody prevalence was 5% in a sample from the general human population and 11% among 347 persons at three research institutions (17% among students, 8% among the research staff). Except for animal caretakers routinely exposed to sheep, antibody prevalence among research staff approximated prevalence in the general population. Suggestions are made for surveillance and vaccination of sheep and goats used in medical research institutions.

Animals↗

PubMedDate not supplied

Epidemiologic study of physiological effects in usual and volunteer citrus workers from organophosphate pesticide residues at reentry.

Biological parameters associated with organophosphate (OP) pesticide exposure were evaluated in a study of citrus harvesters. Changes in these parameters related to environmental residues of cholinesterase (ChE) inhibiting pesticides were studied. Further, it was determined whether usual and volunteer workers differed in their biochemical parameters after exposure to pesticide residues during field operations. Urine metabolite findings for usual farm workers showed that some exposure to OP pesticides had occurred. Too few workers were available during the reentry stage of the field study to evaluate the effect of this exposure on blood ChE. Baseline (nonexposure) acetylcholinesterase (AChE) and plasma cholinesterase (PChE) activities were significantly higher in usual (Mexican American) workers than in volunteer workers (student volunteers). Student volunteers in the test citrus grove showed statistically significant declines in PChE during the exposure period, yet changes in AChE activity, urine metabolites, and residue levels were very small. The implications of these findings are discussed in light of current reentry standards as well as future epidemiologic studies on reentry research.

Cholinesterases↗

PubMedDate not supplied

Silica-containing urinary calculi in dogs (1981-1993).

Silica-containing urinary calculi obtained from 773 dogs and submitted by veterinarians throughout the United States were analyzed by quantitative crystallographic analysis to determine mineral composition. Specimens were composed of either multiple mineral layers (535 specimens) or 1 mineral layer (238 specimens). Most multiple-layer calculi were composed of 80% or greater silica (300 of 535, 56%) or 20% to 79% silica (184 of 535, 34%) in any mineral layer. Most 1-layer calculi were composed of 100% silica (212 of 238, 89%). Most dogs forming silica-containing calculi were of male gender (679 of 773, 88%). Bacterial cultures of calculus or urine or both were performed on 49% (376 of 773) of the specimens, and bacterial growth was obtained from 37% (139 of 376) of samples cultured. The prevalence of calculus-associated urinary tract infection was 35% (113 of 321) in males and 47% (26 of 55) in females. The gender prevalence for infection with Staphylococcus species was 16% (51 of 321) in males and 33% (18 of 55) in females. The breed and gender of dogs that formed calculi (silica population) were compared with the hospital population (Veterinary Medical Teaching Hospital [VMTH] population) and with a population of calculus-forming dogs (Stonelab population) to determine risk factors for silica calculus formation. For all breeds compared, the ratio of males to females was higher in the silica population. The German Shepherd Dog and Old English Sheepdog were significantly overrepresented when the silica population was compared with either the VMTH population or the Stonelab population. We conclude that male German Shepherd Dogs and Old English Sheepdogs are at increased risk for formation of silica-containing urinary calculi.

Animals↗

PubMedDate not supplied

Renal calculi in dogs and cats: prevalence, mineral type, breed, age, and gender interrelationships (1981-1993).

Three hundred seventeen specimens of urinary calculi of renal origin from 214 female dogs and 103 male dogs, and 71 specimens of urinary calculi of renal origin from 38 female cats and 33 male cats were submitted for mineral analysis between July 1, 1981, and December 31, 1993. Among dogs, 45 breeds were affected with renal calculi. Thirty-three breeds and a crossbred group were represented among females, but 8 breeds and the crossbred group accounted for 81% of the total. Among male dogs, 30 breeds and a crossbred group were represented, but 7 breeds and the crossbred group accounted for 69% of the total. Among cats, 10 breeds and a crossbred group were represented. Dogs and cats with renal calculi were older than those of 2 comparison population groups. More than one-half of the renal calculi in both dogs and cats were from the 1st known episode of urolithiasis. The risk of formation of renal calculi was found to be higher for cats than for dogs, when compared to other stone-forming cats and dogs (approximately 4.95 per 100 stone-forming cats and 2.88 per 100 stone-forming dogs). Among dogs, breeds at highest risk of developing renal calculi were Miniature Schnauzers, Shih Tzus, Lhasa Aposos, Yorkshire Terriers, and female Pugs. Also at high risk were male Dalmatians and male Basset Hounds. Among small dogs, females generally were at higher risk of developing renal calculi than were males. Regardless of size, terrier breed males generally were at higher risk of developing renal calculi. Breeds of dogs at low risk for development of renal calculi included crossbreds. German Shepherd Dogs, Labrador Retrievers, Golden Retrievers, and female Dachshunds. When only 1 kidney was involved, the risk of left renal calculus was greatest for both dogs and cats, but bilateral renal involvement was relatively common in both species (19% and 9%, respectively). Among dogs, specimens composed of 1 mineral substance (e.g., struvite) occurred more often in males (58.3%) than in females (37.9%). Female dogs formed renal calculi containing struvite or oxalate more often than did males; males formed calculi containing urate more often than did females. Calculi containing oxalate, apatite, or some combination of these minerals predominated among cats; only 1 specimen from 38 female cats and only 4 specimens from 33 male cats contained neither oxalate nor apatite. Crossbred cats were significantly less likely to have renal calculi than were other breeds. A single renal calculus specimen was identified in several uncommon breeds including Tonkinese and Birman cats, and Affenpinscher, Clumber Spaniel, English Shepherd, and Field Spaniel dogs. No significant differences were observed between male and female dogs or between male and female cats with regard to mineral type of the specimen and the presence of urinary tract infection.

Age Distribution↗

PubMedDate not supplied

Recurrent and persistent urinary tract infections in dogs: 383 cases (1969-1995).

Laboratory records of bacterial urine cultures from 383 dogs with recurrent or persistent urinary tract infections (UTI) diagnosed at the University of California Veterinary Medical Teaching Hospital (VMTH) between 1969 and 1995 were reviewed retrospectively to characterize the bacteria involved and their association with age, gender, and breed of dogs affected. Sixty-eight breeds and a mixed-breed group were represented. Escherichia coli was the most common isolate, although mixed-bacterial infections were seen in 58% of the female and 55% of the male dogs. Recurrent and persistent UTI were most prevalent in middle-aged to older German shepherd dogs, miniature/toy poodles, and Labrador retrievers, with no apparent sex predilection. Criteria fitting recurrent and persistent UTI were present in 0.3% of all dogs seen at the VMTH during this 26-year period.

Animals↗

PubMedDate not supplied

A quantitative study of the effect of endotoxin on embryonating chicken eggs.

A quantitative study of the effect of endotoxin on embryonating chicken eggs revealed the importance of several variables. In the study, the chorioallanotic membrane was detached (i.e.,dropped) from the eggshell membrane on the 9th and 11th incubation days. Various doses of endotoxin in various amounts of diluent were applied on the dropped membrane on the 11th day. Embryo deaths were greater when the membrane was dropped on the 11th day. Within the limits of our trial, the variables were, in decreasing order of significance: 1) the day the membrane was dropped; 2) the amount of endotoxin applied; and 3) an interaction between 1 and 2. The volume of diluent had no significant effect on mortality. The importance of these variables is discussed with reference to the design of additional experiments with endotoxin.

Animals↗

PubMedDate not supplied

Interrelations of organism prevalence, specimen collection method, and host age, sex, and breed among 8,354 canine urinary tract infections (1969-1995).

Selected information was compiled from canine urinalyses and urine cultures conducted between January 1969 and December 1995. Eight thousand three hundred fifty-four microbial isolates (bacteria and fungi) included 4,873 isolates from females and 3,481 from males. Ten bacterial genera accounted for 96.3% of the urinary isolates, including Escherichia coli (44.1%), Staphylococcus spp. (11.6%), Proteus spp. (9.3%), Klebsiella spp. (9.1%), Enterococcus spp. (8.0%), and Streptococcus spp. (5.4%) as the 6 most common isolates in both genders of dogs. Among these 6 genera, female dogs were generally predisposed over males, although males had more urinary tract infections (UTIs) caused by Klebsiella spp. Distributions of ages at UTI diagnosis tended to be similar between genders. Infection with a single microbial species was responsible for >72% of UTIs in both genders. Among females, 40 breeds and a mixed-breed group represented 90.2% of all positive urine cultures, 88.4% of the individual dogs with UTIs. and 88.2% of the microbial isolations. Among males, these same 41 breed groups represented 87.9% of all positive urine cultures, 87.6% of the individual dogs, and 88.2% of the microbial isolations.

Age Distribution↗