A triangular wave microelectrode oscillating apparatus was constructed to evaluate an intracellular recording of rat neuron activity in the medial preoptic area (POA) of the hypothalamus. In this apparatus, electrodes passed a current with a frequency of 1.0 to 1.8kHz and a voltage of 2.2 to 3.2V and produced micro-oscillation of the electrode tip. The electrode was inserted into a neuron of the rat POA in vivo. In vivo recording of the activity of the rat POA neuron was possible. By means of electrical stimulation of the median eminence arcuate of the hypothalamus, an intracellular recording of antidromic, orthodromic or non-responding neuron was also possible. As a result, various components of the action potential such as the resting, threshold and spike potentials, and depolarization and repolarization such as after-hyperpolarization and after-depolarization were observed. The resting potentials ranged from 45 to 90mV, and POA neurons possessed action potentials of almost the same magnitude. Several problems, however, remain to be solved. In general, the time available for the intracellular recordings is too short. The cells survive only for 15 minutes at the longest and may die in only a few minutes. An improvement of the apparatus was mandatory.
A case of Wolff-Parkinson-White (WPW) syndrome in a Holstein-Friesian cow aged 10-year-old was examined in detail. In electrocardiogram (ECG), the P-wave was the same configuration in both the normal and abnormal ECG. The PR-interval shortened from 0.2 to 0.1 second and the duration of the QRS-complex prolonged from 0.1 to 0.12 second compared with normal ECG. The delta wave, characterized in WPW syndrome, could not be recognized. In echocardiogram, notches were recognized at the early stage of ventricular contraction in the interventricular septum. This cow was, therefore, diagnosed as type B WPW syndrome. The abnormal ECG disappeared by the administration of procainamide. It was strongly indicated that the ventricular contraction showing abnormal ECG was generated only by the stimulation through an accessory pathway in this cow.
Ultraviolet (UV)-irradiation of peripheral blood lymphocytes (PBL) of miniature swine prevented them from initiating proliferative responses in allogeneic mixed lymphocyte reactions (MLR). When pigs were given 4 weekly intravenous transfusions of UV-irradiated allogeneic donor PBL differing in major histocompatibility (MHC), PBL of recipient pigs progressively responded less vigorously to donor PBL in MLRs over the treatment period. These pigs did not produce anti-donor PBL antibody. Pigs treated with UV-irradiated PBL also had negligible delayed type hypersensitivity (DTH) responses to donor PBL at the end of the treatment period. In contrast, pigs receiving injections of untreated allogeneic PBL gave strong DTH responses to donor PBL, high proliferation in MLRs with donor PBL and all produced anti-donor PBL antibody.
Isolation of Cryptococcus neoformans was carried out on sunflower seed agar medium (SFA) and Sabouraud dextrose agar (SDA). Out of 346 environmental substrates (133 fruits, 107 avian extreta, 91 vegetables and 15 wooden scrapings) tested, 3 specimens were positive for C. neoformans. The positive isolations came from the fruits of 2 banana (Musa sapientum) and a potato tuber (Solnum tuberosum). The pathogen could not be demonstrated in 107 samples of avian droppings and 15 of wooden materials. All the 3 isolates of the yeast were obtained on SFA, while they were not cultured on the plates of SDA with chloramphenicol which were badly contaminated with rapidly growing molds, yeasts and bacteria. To the present author's knowledge, this appears to be the first reports of the isolation of this pathogenic basidiomycetous yeast from contaminated fruits of banana. We suggest more comprehensive ecological surveys to seach for environmental niche of C. neoformans var. neoformans and C. neoformans var. gattii as the latter variety is also implicated in the etiology of cryptococcosis.
Fecal samples (2, 019) from cattle in the university farm, Tohoku University, were examined for coccidian oocysts from April 1986 to January 1987, and 19.3% of them was positive for Eimeria spp. Thirteen Eimeria species were identified. Eimeria bovis (25.7%) was the most dominant species, followed by E. auburnensis (17.6%), E. canadensis (14.5%), E. alabamensis (9.7%), E. ellipsoidalis (8.1%), E. zuernii (7.0%), E. bukidnonensis (5.4%), E. brasiliensis (3.9%), E. cylindrica (1.3%), E. illinoiensis (0.4%), and E. pellita (0.2%). Fecal samples positive for coccidial oocysts amounted to 12.9% and 26.7% on average during grazing on pasture and loose housing, respectively.
Eighteen canine herpesvirus (CHV) isolates from Japan and two reference strains were compared by restriction endonuclease analysis technique using total DNA extracts from cells infected with the viruses. In order to select the suitable restriction endonucleases for differentiation of CHV isolates, ten enzymes were used and three of them, HindIII, XbaI, and PvuII, were found to be useful for strain differentiation. With these enzymes, CHV isolates from unrelated individuals were readily differentiated from each other. In contrast, all the isolates derived from the same litter were not distinguishable on the basis of restriction cleavage patterns. However, slight mobility shifts were observed among the isolates from the same litter or the same individual. The results showed that this method provides a powerful tool for epidemiological surveys of CHV infection.
To study effects of isoprothiolane and phytosterol on dietary fat necrosis, 3 groups of rats were fed hardened-tallow (HT) diet. Two groups of rats received either isoprothiolane (50mg/kg) or phytosterol (20mg/kg) orally once a day consecutively for 10 weeks. One group of rats received standard diet (CE-2) as a control. Fat necrotic lesions were observed in epididymal and perirenal adipose tissues from all rats in the 3 groups fed HT diet. Rats with fat necrosis were characterized by visceral type obesity and saturation in fatty acid composition of triglyceride in adipose tissue. The highest glucose conversion to total lipids was seen in adipocytes from the rats given phytosterol. There was no lipolytic response to epinephrine stimulation (1-100μM) in adipocytes from the rats given only HT diet, while similar response of adipocytes from the 2 groups treated with either drug to those from the rats fed standard diet was observed. The levels of total saturated fatty acids of phospholipid in adipose tissue from the rats given either drug were lower than that of the rats given only HT diet. These data suggest that either drug alters fatty acid composition of phospholipid in fat cell membrane and enhances lipolysis of the cells.
A simple procedure was developed for detection of Theileria sergenti infection on the basis of hybridization of parasite DNA with a specific probe. A genomic DNA library of T. sergenti constructed in pUC-18 was screened to detect clones containing the parasite's DNA sequences by colony and Southern hybridizations. Two positive DNA inserts were purified from the recombinant plasmids and used as probes labelled with 32P or non-isotopic reagent, biotin-11-dUTP. 32P-radio-labelled and non-radioactive probes appear to be sensitive enough to detect 15 pg (equivalent to 1, 200 parasites) and 125 pg (equivalent to 10, 000 parasites) of purified T. sergenti DNA, and in diluted T. sergenti-infected red blood cells, they are able to detect 8, 000 parasites and 16, 000 parasites, respectively.
Analysis of surface marker of cells after intratumor injection with Nocardia rubra cell wall skeleton (N-CWS) resulted in gradually increasing percentage of macrophage, Pan T and BoCD4+ cells. Proportion of BoCD8+ cells gradually increased from. 4th day and then decreased from 8th day after the injection. Fresh tumor infiltrated cells obtained from lymphatic nodule at 8 days after injection of N-CWS showed cytotoxic activity against bovine leukemia cell line, but this activity decreased with the time of cultivation and no activity could be detected after 14 days cultivation. These cultured cells were injected twice to lymphatic nodule at one week interval for adoptive immunotherapy and found to induce complete regression of nodule after 5 weeks from first injection.
To investigate whether adult heartworms harboring in the pulmonary arteries contribute to pulmonary hypertension, we determined the cardio-pulmonary values immediately before and after removal of heartworms from the pulmonary arteries and before and after insertion of live worms in their place. In 10 heartworm-infected dogs, 8 to 46 worms were removed. The mean pulmonary arterial pressure fell significantly from 24.5±7.9 mmHg to 16.3±4.9 mmHg (p<0.01) immediately after removal. The right cardiac output decreased in 7 of the 10 cases. The total pulmonary resistance and right ventricular stroke work index also decreased. At 24 hours after removal, live heartworms were put back into the pulmonary arteries of their host dog. The mean pulmonary arterial pressure elevated significantly (p<0.01) immediately after insertion. The right cardiac output further decreased in 7 of the 10 dogs, and the total pulmonary resistance and right ventricular stroke work index increased. Separate from this, 12 to 42 heartworms were transplanted into the pulmonary arteries of 5 heartworm-free dogs. Immediately after transplantation, the pulmonary arterial pressure did not show any significant change. However, the stroke volume decreased, and the total pulmonary resistance increased. These facts suggest a contribution of live heartworms to the pulmonary hypertension, although there is a complicated interaction among the presence of heartworms, the pulmonary lesions and the pulmonary hypertension.
Strains of Staphylococcus species isolated from bovine mastitic milk at 66 dairy farms in Japan during the period from November 1988 to May 1989 were identified, and examined for their drug susceptibility and β-lactamase production in order to clarify an epidemiological aspect of bovine mastitis caused by staphylococci. The results of bacteriological identification showed that the most predominant species was S. xylosus. Other major species isolated were S. aureus, S. sciuri and S. hyicus. Thirty-eight (71.7%) isolates of S. xylosus, 21 (45.7%) of S. aureus and 5 (71.4%) of S. epidermidis were positive for β-lactamase production. Most of the β-lactamase-producers of S. aureus were classified as high producers, although all of the β-lactamase-positive S. xylosus isolates remained to be low producers. All isolates of S. aureus were sensitive to methicillin and cloxacillin at 6.25μg/ml and 1.56μg/ml, respectively, and none of methicillin-resistant S. aureus were detected. Isolates of other species were considered to be susceptible to 6 β-lactams, in contrast to human isolates, but antibacterial activities of penicillin G and ampicillin were affected more strongly by β-lactamase than those of methicillin, cloxacillin, cefazolin and cefoperazone.
Colostrum-deprived, neonatal, 2 days old pigs were inoculated with the attenuated HT-/SK or the virulent 90HS strain of porcine parvovirus (PPV) by the oral or subcutaneous route and sacrificed 2, 4 or 6 days after inoculation. Then, comparison was made on viral multiplication in pigs between the two strains. Pigs inoculated with the HT-/SK strain showed no detectable viremia or HI antibody responses against PPV within 6 days after inoculation. Only in pigs inoculated by the subcutaneous route, a small amount of virus was recovered from the spleen, liver, or mesenteric lymph nodes. These viruses were distinguished from the parental virulent 90HS strain, as examined for rct maker in vitro. When pigs were inoculated with the virulent 90HS strain, viremia appeared in all of them 1 day after inoculation and continued for up to the sacrificed day. Moreover, a considerable amount of virus was also detected from all tissues, including brain, lung, liver, spleen, pancreas, small intestine, and lymph node tissues, in all pigs tested. HI antibodies were first detected 6 days after inoculation.
A total of 500 fecal droppings of crows collected from a seashore of an ocean bay and from a cemetery on a hill surrounded by a forest were examined for thermophilic campylobacters, and the Skirrow's biovars and Penner's serogroups of the isolates were determined. The organisms were isolated from 169 (62.6%) of 270 seashore crow samples and 106 (46.1%) of 230 cemetery crow samples. During the investigation period from May 1986 to April 1987, the monthly isolation rate of thermophilic campylobacters in the seashore crow varied from 32.0 to 85.0%. C. jejuni, C. coli, and C. laridis were isolated from 150, 21 and 14 samples, respectively. In case of the cemetery crow, the monthly isolation rate varied from 20.0 to 75.0%, and C. jejuni, C. coli, and C. laridis were detected from 80, 12 and 16 samples, respectively. Among 192 strains of C. jejuni selected from 98 seashore and 57 cemetery crow samples, 106 (93.0%) of 114 seashore crow strains and 69 (88.5%) of 78 cemetery crow strains were identified as Skirrow's biovar I. Of 192 strains of C. jejuni serogrouped, 169 strains were classified into 20 serogroups. The Penner's serogroup 2, one of common serogroups among poultry and human isolates in Japan, was the most predominant in crow strains.
The correlation between haptoglobin (Hp) and mucoprotein or sialic acid in sera from diseased cattle was examined to evaluate the clinical application of serum Hp. First, the ranges of mucoprotein, sialic acid and hemoglobin binding capacity (HbBC) of 46 healthy cattle were determined. Then, levels of these reactants in 35 cattle suffering from various diseases were measured. The frequency of the abnormal values was 94.3% in mucoprotein, 45.7% in sialic acid and 82.9% in HbBC in diseased cattle. There was a significant correlation between mucoprotein and sialic acid, and between HbBC and mucoprotein of sialic acid. Some correlation between mucoprotein and neutrophils or α-globulin was also observed. In spite of high levels of mucorprotein and sialic acid, lower HbBC than expected levels were often observed in inflammatory disorders. Such cases might be complicated with some hemolytic disorders such as piroplasmosis. Determining serum HbBC together with other acute phase reactants might be useful for evaluating inflammatory diseases complicated with hemolytic disorders.
The characteristics of developing intraerythrocytic stages of T. sergenti were studied by light and transmission electron microscopy. The parasites with many ribosomes, acristate mitochondria, cytostome, and food vacuoles were morphologically regarded as the trophozoite stage. Although this type of parasites was frequently detected, intraerythrocytic merozoite stage with electron dense cisternae, rhoptries and small electron dense bodies was rarely observed in high parasitaemia. The intraerythrocytic stages of T. sergenti were divided mainly into four daughters by schizogony, and alternatively into two by binary fission. The daughter parasites in each division had the same ultrastructural features as of merozoites. As a result, it was suggested that T. sergenti trophozoites multiplied by schizogony to four organisms or by binary fission in the peripheral erythrocyte, and differentiated to the merozoites which acquired penetrating ability into the erythrocytes.