High expression of 92 kDa type IV collagenase (matrix metalloproteinase-9) in canine mammary adenocarcinoma.

The 92 kDa type VI collagenase (matrix metalloproteinase-9 (MMP-9)) activities on zymography assay were found to be 1-6 times higher in benign tumor breast tissues of 12 canines and 4-26 times higher in adenocarcinoma breast tissues of nine canines than that of control tissues, respectively. A full-length canine MMP-9 cDNA was cloned from the adenocarcinoma tissue by reverse transcription-PCR and 5'- and 3'-RACE. The isolated cDNA contained an open reading frame coding for a polypeptide of 704 amino acids. The predicted protein sequence displayed extensive similarity to that of known MMP-9s and contained a putative signal sequence, a propeptide, an active site with three zinc-binding histidine residues, a calcium-binding domain, a hemopexin region, and three key cysteine residues. Western blotting using MMP-9-specific antibodies prepared against the peptide corresponding to Arg(642)-Asp(704) of canine MMP-9 and Northern blotting using a MMP-9-specific cDNA fragment as a probe confirmed that MMP-9 (the 92 kDa protein band) was highly expressed in canine mammary adenocarcinoma tissues. Higher levels of MMP-9 activity were found in the sera of canines with mammary adenocarcinoma. The results indicated that MMP-9 plays an important role in the progression of a canine mammary tumor and that assay of serum MMP-9 is helpful for early diagnosis as progress of adenocarcinoma.

Natural Echinococcus multilocularis infection in a Norway rat, Rattus norvegicus, in southern Hokkaido, Japan.

Forty-two rats, Rattus norvegicus, captured at a garbage dump in southern Hokkaido, Japan, were examined, and one was found to be infected with Echinococcus multilocularis. The lesions were found in the liver, lung, mesenteric lymph nodes, greater omentum and also free in the abdominal cavity. No necrosis was observed in any of the lesions, and inflammatory reactions were mild. Protoscoleces were observed in the large liver cysts. A homogenate of these cysts, when transplanted into the abdominal cavity of three Mongolian gerbils and a rat, yielded numerous fully developed protoscoleces at 4-7 months post-inoculation. Judging from this, it is postulated that the rat could become a natural intermediate host for E. multilocularis in this area.

Trial-and-error correlation learning.

A new learning architecture is proposed for hardware implementation of neural networks. In this architecture, each synaptic weight is intentionally changed for each trial and then modified in proportion to the trial-and-error correlation between the changes in the weight and the total output error. If the weight changes are small, this learning is almost as good as the backpropagation (BP) learning, without requiring a complex backward network for error backpropagation. If the changes are large, the weights can move in the weight space without being restricted to a relatively small local-minimum. Computer simulation shows that this learning surpasses BP learning in converging to the global minimum when the trial-and-error correlation is defined so as to emphasize the gain (i.e., the decrease in the total output error) rather than the loss.

Nematodes of armadillos in Paraguay: a description of a new species Aspidodera esperanzae (Nematoda: Aspidoderidae).

Twelve species of nematodes comprising 9 genera were recovered from the gastrointestinal tract of 2 Euphractus sexcinctus and 2 Dasypus novemcinctus captured in the Department of San Pedro, Paraguay. All armadillos were infected with 1 or more species of nematode. The following nematodes were recovered: Mazzia mazzia, Spirura guianensis, Trichohelix tuberculata, Ancylostoma sp., Moennigia complexus, Moennigia pintoi, Ascaris dasypodina, Cruzia tentaculata, Aspidodera fasciata, Aspidodera scoleciformis, Aspidodera esperanzae n. sp., and Heterakinae gen. sp. This report describes a new species of the Aspidodera nematode, Aspidodera esperanzae n. sp., the first species to be reported bearing cephalic cordons made up of 7 longitudinal loops in the subfamily of Aspidoderinae. This study also documents a new host record for S. guianensis and shows a new geographical distribution in Paraguay for M. mazzia, S. guianensis, T. tuberculata, M. complexus, and M. pintoi.

Animal reservoirs for Trypanosoma cruzi infection in an endemic area in Paraguay.

Animal reservoirs for Trypanosoma cruzi infection were investigated in 5 communities in the Department of San Pedro, currently one of Paraguay's most highly endemic areas. A total of 112 domestic animals (37 cattle, 2 horses, 1 ass, 20 pigs, 44 dogs and 8 cats) and 4 wild animals (1 white-eared opossum, 2 yellow armadillos and 1 common long-nosed armadillo) were examined for blood. Although no trypomastigotes were found by 2 direct observation methods, the microhaematocrit and Giemsa stained thick and thin smears methods, several forms of trypanosoma flagellates morphologically identical to T. cruzi were detected in the liver infusion tryptose (LIT) medium from a single sample taken from a yellow armadillo, Euphractus sexicintus. When serum samples of all the animals were examined for antibody to T. cruzi by direct agglutination (DA) test, 3 cattle, 2 pigs, 16 dogs and 3 cats had positive titers (1:32 or greater), but no wild animals showed positive reactions. T. cruzi was not found by culture nor microscopic examination of samples from any of the seropositive animals. However, domestic animals such as cattle, pigs, dogs and cats which were found to be seropositive in this study, possibly act as an animal reservoir in this endemic area as well as armadillos in which T. cruzi was observed.

Parasites from the Asiatic black bear (Ursus thibetanus) on Kyushu Island, Japan.

Two Dirofilaria ursi, six Trichodectes pinguis and numerous Haemaphysalis megaspinosa were obtained from an Asiatic black bear (Ursus thibetanus) shot in Kyushu, Japan. The presence of two parasites specific to black bears may indicate the existence of a wild population, although the bears are regarded to be extinct on Kyushu Island.

[Behavior-genetic analysis of responses in runway test as measures of emotional reactivity in rats: I.- phenotypic variations and heritability estimates based on offspring-parents regressions (author's transl)].

Individual differences of emotional reactivity were estimated from 6 kinds of responses measured in the Runway Test (modified ("Timidity Test") in 974 random-bred albino rats. 3 different estimates of heritability of these responses were calculated from the regressions of offspring on dam, sire, and midparent. The types and degree of the phenotypic variations are very different among the responses measured. Heritability estimates of 2 kinds of responses which are related to the behavior going to the remotest part of runway from starting box were relatively higher (.30-.55). Heritability estimates of starting latency, time in the starting box, and the number of sections rats traversed were medium (.20-.40). The estimates from defecation scores had lowest (.10-.30).

[The genetic architecture of emotionality in rats using Mendelian cross analysis].

Two inbred strains of Tsukuba Emotionality Rat (THE and TLE) and four hybrids derived from them were observed for ambulatory response in a novel environment as a measure of emotionality. The Runway Test (modified "timidity test") was run for successive three days. Mean transformed (square root) scores of ambulation for generation were subjected to Mendelian cross analysis. Total ambulation scores showed significant additive genetic effect, maternal effect and environmental effect. Directional dominance toward low level of response was present only for males. Daily ambulation scores showed changes in the genetic architecture over three days and the difference between males and females. For females, directional dominance occurred toward low level on Day 1, toward high level on Day 3, but no directional dominance was observed on Day 2. Males' directional dominance toward low level, on the other hand, declined with days. These findings on the genetic architecture of emotionality were discussed with reference to evolutionary adaptation.

[Effect of interrun interval on serial pattern learning in rats].

The effect of interrun interval (IRI) on serial pattern learning was investigated in a runway. One of two serial sequences, a monotonic decreasing sequence (14-7-3-1-0 food pellets) or a nonmonotonic sequence (14-1-3-7-0), was combined factorially with a short (30 s) or a long (30 min) IRI. Following 28 acquisition trials, a short (or long) IRI was transferred to the same sequence with a long (or short) IRI. It was found that anticipation of the O-pellet developed more rapidly in the group receiving a monotonic sequence with a 30 s IRI than that with a 30 min IRI in acquisition phase. The O-pellet was not anticipated by either of the two nonmonotonic groups. Anticipation was eliminated by the increase in IRI, whereas it was developed by the decrease in IRI in the monotonic sequence. These results suggest that time-related factors such as the decay of the memory of numbers of pellets are needed for Capaldi's memory discrimination theory.

[Behavioral comparisons of rats (Rattus norvegicus) in Runway, open-field, and I-maze].

Behaviors of two strains of rats (F344/DuCrj and Wistar-Imamichi) in three novel situations (Runway, open-field, and I-maze) were compared in order to clarify the characteristics of each situation. Eighty rats were used; 40 were F344/DuCrj and 40 were Wistar-Imamichi. Principal component analysis of each ambulation score abstracted two major components of 'activity' and 'emotionality'. Highly 'active' rats ambulated much in the three situations, whereas highly 'emotional' rats ambulated much in the open-field test and little in the Runway test. These results suggest that there appeared 'escape response' in the open-field test, while 'freezing response' occurred in the same rat in the Runway test. Wistar-Imamichi was more 'active' than F344/DuCrj, whereas the latter was more 'emotional' than the former. This study also confirmed the idea that the rats were frightened in I-maze less than in Runway.

[Study of suckling behavior in the rat: the effects of food deprivation of pups and lactational age of mother].

The effects of food deprivation (0-1, 2-3, and 22-23 h) of pups and of lactational age of mother (1-7 days, 16-22 days and own mother) upon suckling behavior of pups were investigated with the mother anesthetized. The effect of food deprivation was not evident prior to 11 days of age but deprived pups showed higher level of suckling than non-deprived pups at 16 and 21 days of age (Experiment 1). The effect of lactational age of mother was not found at 6-17 days of age but pups at 1-2 and 21-22 days of age showed lower level of suckling to the anesthetized mother which differed in lactational age from their own mother (Experiment 2).

[Transition of occurrence of anisakiasis and its paratenic host fishes in Japan, with pathogenesis of anisakiasis].

The number of anisakiasis according to a nation-wide statistical survey totaled 4682 cases until June 1987 in Japan. Of these 4296 cases are gastric anisakiasis (including 215 cases of gastric terranovasis), 375 intestinal anisakiasis and 11 extra-gastrointestinal anisakiasis. Pseudoterranova larva does not invade the intestine, and worms are vomited in most cases. Clinical diagnosis of intestinal anisakiasis is more difficult than that of gastric anisakiasis, and it also is hard to find the worm itself in histopathological examination. Therefore the number of actual intestinal anisakiasis is probably 3 times more than that of the reported cases. The cases of gastrointestinal-wall perforation by worms are increasing, which means immune response by granuloma formation is important. The catches of paratenic hosts and the rate of infection vary with year. In addition, the kind of paratenic host fishes are different between the southern and northern areas of Japan. The paratenic hosts reported by patient are closely related to the catches of kinds of those fishes in the respective areas. Recently, cases by eating sardine are increasing in the southern area. Urticaria as a complication is related to the diagnostic rate, and intraperitoneal bacterial infection by the gastrointestinal perforation by worms is closely related to the prognosis.

Seroprevalence of tularemia in wild bears and hares in Japan.

Tularemia is a zoonotic disease caused by Francisella tularensis. The distribution of the pathogen in Japan has not been studied well. In this study, seroprevalence of tularemia among wild black bears and hares in Japan was determined. Blood samples collected from 431 Japanese black bears (Ursus thibetanus japonicus) and 293 Japanese hares (Lepus brachurus) between 1998 and 2009 were examined for antibodies against F. tularensis by micro-agglutination test (MA) or enzyme-linked immunosorbent assay. By subsequent confirmatory tests using western blot (WB) and indirect immunofluorescence assay (IFA), eight sera from Japanese black bears were definitely shown to be seropositive. All of these eight bears were residents of the northeastern part of main-island of Japan, where human tularemia had been reported. On the other hand, no seropositive Japanese hares were found. These results suggest that Japanese black bears can serve as sentinel for tularemia surveillance and may help understand the distribution of F. tularensis throughout the country. This is the first report on detection of antibody to F. tularensis in black bears of Japan.