Preparation of large temporomandibular joint specimens for pathological study

Ten fresh temporomandibular joint (TMJ) specimens about 5 X 4.5 X 3.5 cm in size were removed at autopsy by 5 cuts according to appropriate anatomical landmarks. After routine formalin fixation, the whole-TMJ specimens were wrapped with a thin layer of self-curing resin and then cut with a low speed bone saw along the parasagittal plane predetermined by x-ray guidance. Each specimen was serially cut into 4 to 5 parallel slices of 3 mm thickness, which were then decalcified with 14% EDTA and embedded in paraffin. Histological sections of 5 microns were stained with hematoxylin and eosin. The procedures were accomplished within 20 to 24 days after autopsy. With this technique, the anatomical interrelationships among the various joint components could be maintained and the macroscopic and microscopic topography of the TMJ could be studied in the desired reference plane. Therefore, the corresponding changes among the joint components in a diseased TMJ could be thoroughly examined. This technique was also applicable for the study of large specimens containing both hard and soft tissues.

[Effect of dexamethasone-A synthetic glucocorticoid hormone on the immune response in pigs]

These experiments were designed to study the effects of a synthetic drug--dexamethasone (DEX) on the immune response of weaned pigs against viral antigen (hog cholera vaccine) and bacterial antigen (formalin inactivated Salmonella enteritis vaccine). Twenty-three five-week-old pigs were divided into eight groups, six of which were injected twice daily with DEX at 1.0 mg or 0.1 mg per Kg of body weight for either four or five days. The other two groups served as controls. During this period, the two 0.1 mg/Kg DEX-treated groups were injected with live hog cholera vaccine at 1.0 or 0.1 dosage respectively. This same treatment was applied to the two 1.0 mg/Kg DEX-treated groups. One control group was injected with a dose of hog cholera vaccine, while the other was given 1.0 ml of Sal. enteritis vaccine. The hog cholera antibody response in DEX-treated pigs was significantly suppressed (p less than 0.01). However, consistent levels of antibody titers were maintained, indicating a slight antibody production. But in pigs injected with one tenth of the normal dose of hog cholera vaccine, there was little or no immune response (p less than 0.01). A comparison of the response of pigs given different levels of DEX concentrations to those with different doses of hog cholera vaccine showed that dexamethasone significantly suppressed antibody production when antigen concentrations were lower. Significant suppression of agglutinating antibody in response to bacterial antigen was also observed at 14 days post-vaccination (p less than 0.05).

Interaction between bound cupric ion and spin-labeled cysteine beta-93 in human and horse hemoglobins

The location of the various copper binding sites for horse and human hemoglobin was probed using spin labels attached to the beta-93 cysteine residue. Dipole-dipole interactions between the spin label and bound copper produce a decrease in the amplitude of the spin label spectrum which was used to estimate the Cu(II) spin label distance. By comparing the results with horse and human hemoglobin at 298 and 77 K four different Cu(II) binding sites were identified. The low affinity horse hemoglobin site with the sulfhydryl blocked (site 1) was found to be located 10-13 A from the sulfhydryl spin label on the surface of the molecule. Only with a free sulfhydryl is the site (site 2) in the pocket between the F and H helices closer to the SH-group and the iron populated. It is site 2 which is responsible for the oxidation. In frozen solutions a Cu-nitroxide distance of about 17 A was determined with human hemoglobin. This distance is consistent with the previously postulated location of the "high affinity" human hemoglobin site near the amino terminus of the beta-chain. At 298 K a much shorter Cu-nitroxide distance of about 7 A was calculated for human hemoglobin. This shorter distance at higher temperature also correlated with a slightly smaller value of g11 and A11 for the Cu(II) ESR spectrum. It is postulated that in solution cross-linking between nitrogenous ligands in the region of the amino terminus of one beta-chain and the carboxyl terminus of the other beta-chain can explain this shorter distance. This cross-link could involve histidine beta-143, which is one of the ligands thought to be also involved in site 1. Binding to the "high-affinity" site in solution thus stabilizes the "low-affinity" site 2 relative to site 1 explaining the reported interaction between the "high-affinity" and "low-affinity" sites.

Effects of aging on the lipid order and composition of rat adipocyte ghosts

An analysis of the cholesterol/phospholipid ratio of adipocyte ghosts from rat epididymal fat pads shows a significant increase with age (P less than 0.005). An attempt to correlate these changes with the order of the lipid matrix was made using the stearic acid spin label 2-(3-carboxypropyl)-4, 4-dimethyl-2-tridecyl-3-oxazolidinyloxyl [I(12,3)]. Although order was negatively correlated with temperature in preparations from both 6- and 24-month-old rats, no effect of age could be detected.

Comparison of the genomes of pseudorabies (Aujeszky's disease) virus strains by restriction endonuclease analysis

The DNA of pseudorabies virus (PRV) strains from the United States and Taiwan and attenuated vaccine strains from Romania were compared by restriction endonuclease analysis. Electrophoretically separated PRV DNA fragments of KpnI and BamHI digests demonstrated cleavage pattern variations which clearly distinguished the 3 Taiwan isolates from all other strains, as well as from each other. One type of variation involved the loss or gain of restriction endonuclease cleavage sites. Examples of this type of variation were clearly observed in fragment patterns of the Taiwan isolates. Another type of variation that occurred at higher frequency for fragments mapping in the repeat and repeat-unique joint regions of the PRV genome involved sequence additions or deletions from existing fragments. This second type of variation occurred in most of the strains analyzed.

A histological study of the promotive effect of diethylstilbestrol on diethylnitrosamine initiated carcinogenesis of liver in rat

A single dose (80 mg/kg) of diethylnitrosamine (DEN) was given orally to castrated female Wistar rats. One week after that one half of the animals were treated with diethylstilbestrol (DES) 3 mg/kg/once a week subcutaneously. The other half of the animals received no any hormone or hormone derivatives. The change of the liver cells in animals treated with DEN alone failed to progress beyond the stage of hepatocellular alterations in foci or neoplastic nodules within 8 months, while most of those animals which received DES treatment after DEN initiation developed hepatocellular carcinomas after 6 months. This result denotes that the DES exerts a definite promotive effect on DEN initiated liver cell carcinogenesis.

Purification and characterization of the estrogen-induced protein (IP) of the rat uterus

One of the earliest responses of the rat uterus to estrogen is increased synthesis of a specific cytosol protein (IP). This synthesis is detectable within 40 min and is dependent on an even earlier actinomycin D-sensitive function. IP has now been purified to homogeneity as determined by SDS polyacrylamide gel electrophoresis (SDS PAGE). The procedure was complicated by a tendency of the more homogeneous and concentrated material to aggregate. Purification consisted of sequential chromatography, in the presence of 0.1% triton X-100, via DEAE-cellulose (2x), hydroxylapatite and agarose-acrylamide. These were followed by preparative PAGE and finally SDS PAGE. Molecular weight determination by Ferguson plot analysis yielded an apparent molecular weight of 45 000. On final SDS PAGE, the material consisted of two major bands: the 45 000 molecular weight IP band and a band with an estimated molecular weight of 80 000. This second band displayed an elevated synthesis in E2-stimulated uteri similar to IP and appeared to consist of some form of aggregated IP. Carbohydrate determination on SDS gels using periodic acid-Schiff (PAS) stain was negative. Co-purification of labeled cytosol proteins from uteri of control and E2-stimulated rats revealed that IP is synthesized to some extent in the unstimulated animal as well as the stimulated.

Demonstration of feline leukemia virus antibody in cats by passive hemagglutination (38583)

Two FeLV fractions from Sephadex G-150 gel filtration were used to sensitize RBC for the PHA test. When the cells were coated with the fraction from the second peak consisting mostly of a mojor gs antigen of FeLV, no antibodies could be detected either in hyperimmunized cat sera or sera from leukemic cats, whereas antibodies were readily detectable in immunized rabbits. Using cells coated with the first peak eluants or Tween-ether disrupted FeLV, PHA antibodies were detected in cat sera. There existed, however, one significant exception that a cat with the diagnosis of mast cell leukemia showed antibody against the second peak fraction. Little or no antibodies could be detected in cat sera by CF or gel-diffusion. There was some correlation between hemagglutinating antibodies and conglutinating complement absorbing antibodies, but these antibodies did seem to differ from neutralizing antibody.

Classification of North American porcine enteroviruses: a comparison with European and Japanese strains

Seventy-two strains of porcine enteroviruses including strains from North America, England, and Japan were compared by cell culture neutralization tests to provide a serological classification of North American strains. From the tests, eight serogroups evolved, with serogroup 8 having a possible three subgroups. There appeared to be some intergroup relationship among certain viruses in groups having the same specific cytopathic effect (CPE) in cell culture. There was no apparent cross-reaction between the group with type II CPE and groups with type I CPE. Antisera produced in nonhost chickens provided a satisfactory antibody source for the tests. It was proposed that satisfactory typing of viruses could be done best by cross-neutralization rather than by one-way neutralization tests. This provided the homologous serum titer as determined in the laboratory conducting the tests which was important where comparisons are made on the basis of per cent of the homologous titer. It was further emphasized that viruses of tissue origin and their antisera have fewer intergroup reactions than viruses of intestinal origin and their antisera. General type strains and specific North American strains were suggested as satisfactory type sera and viruses for seven of the eight groups to facilitate virus identification.