Elution characteristics of vancomycin, teicoplanin, gentamicin and clindamycin from calcium sulphate beads.

The in vitro release of vancomycin, teicoplanin, gentamicin and clindamycin from biodegradable calcium sulphate (CaSO(4)) carrier beads is described. All antibiotics showed prolonged release from the carrier beads, which was elevated during the first 24 h, with peak levels exceeding 2500 microg/bead. Doubling the antibiotic load of the beads revealed a more prolonged elution and a two-fold increase in antibiotic release. Local carrier-associated antibiotic treatment with CaSO(4) beads may prove to be effective in the management of chronic bone infections.

Grb2-associated binder-1 mediates phosphatidylinositol 3-kinase activation and the promotion of cell survival by nerve growth factor.

Nerve growth factor (NGF) prevents apoptosis through stimulation of the TrkA receptor protein tyrosine kinase. The downstream activation of phosphatidylinositol 3-kinase (PI 3-kinase) is essential for the inhibition of apoptosis, although this enzyme does not bind to and is not directly activated by TrkA. We have found that the addition of NGF to PC-12 cells resulted in the phosphorylation of the Grb2-associated binder-1 (Gab1) docking protein and induced the association of several SH2 domain-containing proteins, including PI 3-kinase. A substantial fraction of the total cellular PI 3-kinase activity was associated with Gab1. PC-12 cells that overexpressed Gab1 show a decreased requirement for the amount of NGF necessary to inhibit apoptosis. The expression of a Gab1 mutant that lacked the binding sites for PI 3-kinase enhanced apoptosis and diminished the protective effect of NGF. Hence, Gab1 has a major role in connecting TrkA with PI 3-kinase activation and for the promotion of cell survival by NGF.

Experimental Brucella suis biovar 4 infection in a moose.

A moose (Alces alces gigas) was inoculated with Brucella suis biovar 4 to better understand the effects of brucellosis in this species. Serum antibody titers increased rapidly and peaked within 21 to 56 days. Fever, leukocytosis, recumbency, anorexia and depression were observed starting 42 days post inoculation. Brucella suis biovar 4 was isolated from blood, lymph nodes, liver and spleen.

Attempted reactivation of contagious ecthyma in Dall sheep.

Dexamethasone was administered to 2 Dall ewes that had clinically recovered from contagious ecthyma in an attempt to reactivate contagious ecthyma in the sheep. Clinical signs of disease were not detected within 24 days after corticosteroid injection, and virus was not detected in tissues collected at necropsy.

Serologic and experimental investigations of contagious ecthyma in Alaska.

Serologic evidence of contagious ecthyma (CE) was found in domestic sheep (Ovis aries), domestic goats (Capra hircus), Dall sheep (Ovis dalli), and musk-ox (Ovibos moschatus) in Alaska. A moose (Alces alces) calf and a caribou (Rangifer tarandus) fawn were susceptible to experimental infection and both developed antibody titers as a result. CE virus was isolated from lesions of Dall sheep which were involved in a natural outbreak of the disease.

Trypanosoma cervi from Alaskan reindeer, Rangifer tarandus.

Twenty-nine (64.4%) or 45 reindeer, Rangifer tarandus, examined over a two-year period were infected with trypanosomes. Trypomastigotes and dividing epimastigotes were found in the blood of fawns, cows, and bulls. Morphometric analysis of bloodstream trypomastigotes from reindeer and comparison of these parasites with similar stages of trypanosomes from elk, mule deer, and white-tailed deer from the continuous United States proved them conspecific; the trypanosomes from these members of the Cervidae are identified as Trypanosoma cervi Kingston & Morton, 1975. This is the first report of trypanosomes from reindeer. No pathogenic effects are known to be caused by these parasites.

Vesicular exanthema of swine and San Miguel sea lion virus: experimental and field studies in otarid seals, feeding trials in swine.

The naturally occurring disease caused by San Miguel sea lion virus in fur seals was characterized by small fluid-filled vesicles 1 to 25 mm in diameter on the nonhaired portions of the flippers. Early epithelial lesions contained multifocal sites of cell lysis. The resultant microvesicles enlarged and coalesced, forming grossly visible macrovesicles. Mature vesicles progressed to involve all layers of the epithelium but did not involve the underlying dermis. Intradermal inoculation of vesicular exanthema of swine virus type A48 or San Miguel sea lion virus type 2 into otarid (fur) seal pups caused plaque-like lesions around inoculated coronary bands. These swellings regressed without rupture by 96 hours postinoculation. One seal inoculated with San Miguel sea lion virus had a linear lingual erosion at ten days postinoculation. Virus was isolated from this site and from two uninoculated sites, the tonsil and testicle. Contact controls showed no evidence of infection. Virus was isolated in low titers from some sites of inoculation and draining lymph nodes from seals infected with vesicular exanthema of swine virus. Virus was recovered more easily, in higher titers, and from more tissues, from seals infected with San Miguel sea lion virus. Inoculated seals tested after four to ten days seroconverted. Feeding swine seal tissues from the inoculation experiments resulted in seroconversion in swine which were fed tissues from seals infected with vesicular exanthema of swine virus but not in those which were fed tissues from seals infected with San Miguel sea lion virus.

Contagious ecthyma in Alaskan musk-oxen and Dall sheep.

In 1976 and 1977, a disease resembling contagious ecthyma was seen in captive musk-oxen (Ovibos moschatus) in Alaska. A similar disease occurred in 1977 in captive Dall sheep (Ovis dalli). Paravaccinia viruses were detected by electron microscopy and isolated in cell cultures from both species. Experimental inoculation in susceptible and immune domestic sheep (Ovis aries) plus fluorescent antibody tests with ecthyma-immune conjugate indicated that the isolate was contagious ecthyma virus.

Effects of killed Brucella abortus strain 45/20 vaccine on reindeer later challenge exposed with Brucella suis type 4.

Six seronegative pregnant reindeer (Rangifer tarandus L) were vaccinated with killed Brucella abortus strain 45/20 with added adjuvant. These were challenge exposed with B suis type 4 after 90 days; at the same time, 4 seronegative, nonvaccinated, pregnant reindeer (controls) were given the challenge inoculum. Humoral antibodies were detected in the vaccinated reindeer by postvaccination day 14. A marked increase in antibody levels also occurred after they were challenge exposed, but did not reach the levels observed in control reindeer which seroconverted within 8 days after they were given the challenge inoculum. One control reindeer aborted at 45 days after challenge exposure (at 165 days of a normal 225-day gestation period), and the fawn of another lived only a few days after delivery. Brucella suis type 4 was isolated from tissues of 3 of 4 control reindeer and of 2 of their fawns. All vaccinated reindeer gave birth to live fawns which were culture negative, although 1 fawn lived only a few days. Brucella suis type 4 was isolated from tissues of 1 vaccinated reindeer. Under the conditions of this experiment, killed B abortus 45/20 vaccine provided increased resistance to brucellosis.

An investigation of arterial disease in Alaskan reindeer and Caribou.

No significant lesions of atherosclerosis or other vascular diseases were found in the aorta and coronary arteries of 34 reindeer and 15 caribou (Rangifer tarandus). Serum lipid, phospholipid, cholesterol and triglyceride levels were similar in caribou and reindeer and did not differ greatly from those reported in other ruminants.

Avian pox infection in an American green-winged teal (Anas crecca carolinensis) in Alaska.

Poxvirus infection was diagnosed on the basis of gross and microscopic appearance plus the presence of typical inclusion bodies in a juvenile American green-winged teal (Anas crecca carolinensis) in Alaska. This constitutes the first known report of avian pox in migratory ducks and the first report of poxvirus infection in wild birds in Alaska.

Atherosclerosis in lemmings and voles fed a high fat, high cholesterol diet.

Two species of lemmings and two species of voles were fed a high fat, high cholesterol diet for several months. Clethrionomys rutilus had a moderate (2x) rise in serum cholesterol while Microtus oeconomus had a marked increase (5x); Dicrostonyx stevensoni and Dicrostonyx rubricatus had extreme increases (8x and 11x, respectively). Typical lesions of atherosclerosis were observed in all species, but D. rubricatus had significantly more severe lesions. Hepatic fatty infiltration was the principal pathologic lesion found besides atherosclerosis in those test rodents which died spontaneously.

Mandibular lesions in the Western Arctic caribou herd of Alaska.

Lesions were noted in 7.0 and 4.4% of mandible pairs collected from the Western Arctic caribou herd of northwestern Alaska in 1959-61 and 1975-77, respectively. The prevalence of mandibular lesions in the 1959-61 collection is believed to be the highest reported in wild caribou herds of North America. The frequency of occurrence of mandibular lesions was highest in caribou 7 years of age and older, and there was a higher prevalence in adult males than in adult females. Trauma, dental abscesses, and periodontal disease were the probably cause of most lesions. Pathogenic bacteria were not isolated from mandibular lesions from an 11 year-old female. Thirty-three of 98 (33.7%) mandibles with lesions were missing one tooth, while ten (10.2%) were missing more than one tooth. The first molar (M1) was the most common tooth lost in association with lesions, although the loss of two or more teeth was more common among premolars than among molars.

Postnatal changes in body composition of laboratory maintained brown lemmings, Lemmus sibiricus.

Postnatal changes in the body composition components, namely, body water, fat-free dry solids, and fat, were determined for laboratory-maintained brown lemmings, Lemmus sibiricus. The proportion of body water decreased while the proportion of fat-free dry solids and fat increased from birth to approximately 15 weeks of age. From 20 through 80 weeks of age, the proportions of all body composition components as well as total body weight remained relatively constant. Body composition components were more closely correlated with body weight than with chronologic age. As a function of body weight, body water decreased while fat-free dry solids and fat increased. Body fat was the most variable body composition component as related both to body weight and chronologic age. The von Bertalanffy growth equation and the differential growth equation were used to describe the body composition component data as related to chronologic age and body weight, respectively.

Quantitative morphological analysis of glomerular changes of the rabbit kidney on treatment with insulin preparations of different purity.

Thirty rabbits were immunized with MC insulin and high-molecular impurities of commercial insulin preparations (a+b component) over 30, 60 and 90 days. The serum insulin antibody titer was determined in animals as the insulin binding capacity. Further, a quantitative morphological analysis of the various types of glomerular cells and of the mesangium was performed on the glomeruli as a blind study. Significant mesangial cell proliferation and an increase in mesangial matrix were found on treatment with the a+b component whereas the animals treated with MC insulin exhibited only a transient and slight mesangial activation after 30 days. There was a positive correlation between the magnitude of the insulin binding capacity and the mesangial activation. Hence, the glomerular changes which are observed after treatment with insulin which is not highly purified must be attributed to the high treatment with insulin which is not highly purified must be attributed to the high molecular weight contaminants. Heterologous pure insulin must be regarded as having virtually no immunological effect.

Breeding and reproduction of fifteen wild rodents maintained as laboratory colonies.

Data on reproduction and production were presented for laboratory colonies of Microtus pennsylvanicus tananaensis, M oeconomus macfarlani, M o operarius, M mirurus, M abbreviatus, Lemmus lemmus, L sibiricus trimucronatus, Dicrostonyx stevensoni, Clethrionomys rutilus, Peromyscus maniculatus borealis, P m bairdii, Baiomys taylori, Calomys ducilla, C callosus, Acomys cahirinus. Litter size varied from 2.0 in A cahirinus to 5.5 in C callosus. Infant (neonatal) and juvenile losses through the end of the first month ranged from 9% in C callosus to 45% in M o operarius. Young successfully weaned per female ranged from 3.4 in L sibericus to 15.2 in P m bairdii. The number of young weaned per female per month, which may be the most useful measure of production, ranged from 0.6 in A cahirinus to 2.6 in C ducilla. The most common 21-da interval between litters confirms postpartum estrus and mating, and a 21-da gestation in most cricetids.