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Biomedical subjects

M Iseki

Publications and source records attributed to M Iseki.

At least 55 records · Page 3Linked to original sources
PubMed1991

Renal pathology in Saimiri monkeys during a vaccine trial using the recombinant circumsporozoite protein of Plasmodium vivax.

Renal specimens of squirrel monkeys (Saimiri sciureus boliviensis) were studied by light microscopy and immunohistochemistry to examine the pathologic changes during vaccine trials with four recombinant circumsporozoite (CS) proteins (rPvCS-1, rPvCS-2, rPvCS-3, NS1(81) V20) of Plasmodium vivax. The monkeys were vaccinated and later challenged with P. vivax sporozoites. Among the 33 posttrial biopsies, 17 had mild to moderate mesangial proliferation and nine had interstitial nephritis. Immunohistochemistry by the peroxidase-antiperoxidase (PAP) method revealed IgG deposits in only three of 24 specimens and failed to demonstrate C3 deposits and P. vivax antigens in their glomeruli. There was no relationship between the severity of nephropathy and intensity of parasitemia. The intensity of parasitemia was the same in the vaccinated and control groups. Vaccinated monkeys from the groups (rPvCS-1, rPvCs-2, rPvCS-3) had no differences in renal pathology from the unvaccinated controls, but one group vaccinated with NS1(81) V20 did not develop renal changes.

Amino Acid Sequence↗
PubMed1990

Thymolipoma with striated myoid cells. Histological, immunohistochemical, and ultrastructural study.

A large asymptomatic anterior mediastinal thymolipoma, discovered by chest radiograph during a regular check-up for company employees, was excised from a 33-year-old Japanese man. On immunohistochemical and electron-microscopic examination, clusters of myoglobin-positive cells with cytoplasmic Z band structures were found scattered in the medulla. Myoid cells have been previously seen in the normal thymus as well as in thymic hyperplasia, thymoma, and in the thymus of patients with myasthenia gravis. To our knowledge, this is the first reported instance of myoid cells in a thymolipoma.

Adult↗
PubMed1990

A histopathological study on senile changes in the human olfactory bulb.

Senile changes in the human olfactory bulb were studied histopathologically in 133 individuals ranging in age from 40 to 91 years with a mean age of 64.3 years. Neurofibrillary tangles (NFTs) in the olfactory bulb were observed in 47 subjects aged over 50 years. The frequency of NFTs was 35.3% (47/133) in total and 40.5% (47/116) among subjects 50 years of age or older. The frequency of individuals with NFTs increased linearly with age. Senile plaques (SPs) were observed in 5 individuals over 60 years old at a frequency of 3.8% (5/133) in total and 5.7% (5/88) among individuals 60 years old or more. Granulovacuolar degeneration was rarely seen, and amyloid angiopathy was not recognized. Senile changes in the hippocampus and parahippocampal gyrus were also examined. In some cases, the frequencies of NFTs and SPs in the hippocampal region were not identical to those in the olfactory bulb. However, it was not apparent whether senile changes first appear in the olfactory bulb or in the hippocampal region.

Adult↗
PubMed1990

A clinicopathologic study of tumors and tumor-like lesions of the penis.

A total of 147 specimens from 93 patients with penile lesions were examined at Nagasaki University Hospital during a 27-year period from 1961 to 1987. The most frequent malignant tumor was squamous cell carcinoma (SCC, 33 cases, 35.5%), followed by extramammary Paget's disease, transitional cell carcinoma, and Bowen's disease. The benign tumors and tumor-like lesions included condyloma acuminatum, cyst of the genitoperineal raphe, and lymphangioma. SCC of the penis accounted for less than 0.1% of all specimens and less than 0.62% of malignant tumors in men filed at our hospital. True phimosis accompanied 81.5% of the SCC cases. The 5- and 10-year survival rates for SCC were 77.2% and 71.3%, respectively. Two patients died of penile SCC. It was considered that an absence of both keratohyaline granules in the granular layer and melanin pigment in the basal layer can serve as a useful histologic indicator for diagnosis of well differentiated SCCs that are otherwise difficult to identify.

Adolescent↗
PubMed1990

Anaplastic ependymoma of the spinal cord in childhood. A case report.

We report a 6-year-old girl with anaplastic ependymoma probably originating in the region of the conus medullaris and probably spreading retrogradely to the region of the interventricular foramen (Monro) through the cerebrospinal fluid (CSF). Since ependymoma of the spinal cord rarely occurs in children, and retrograde spreading is extremely rare, the histological features and mechanism of metastasis of the tumor are discussed.

Child↗
PubMed1990

[Tetanus antitoxin levels in various Japanese age groups in 1989].

The nationwide DPT vaccine program was started in 1969 for infants under 12 months of age. In order to estimate the tetanus immune status among the general population of various age groups, we measured the serum tetanus antibody level in randomly selected outpatients from Metropolitan Tokyo (n = 211, 6 months-60 years) and Hamamatsu, a city of 510 thousand population (n = 128, 3 years-80 years) between January 1987 and June 1989. Among the 211 subjects from Tokyo, the antibody value exceeding effective level of 0.01 HAU/ml was observed in 102 subjects (48.3%). The antibody positive rate was 90.8% in subjects of 3 to 21 years and was 27.7% in subjects of 22 years or older. The positive rate was significantly higher in subjects of 21 years or younger (p less than 0.005). Among 128 subjects from Hamamatsu, 60 (46.1%) had a positive antibody and the antibody positive rare was 96.9% in subjects of 3 to 21 years and was 29.5% in subjects of 21 years or younger (p less than 0.005). The above findings indicate that our DPT vaccination program has been functioning well for the last 20 years and that the immunized population is adequately protected against tetanus.

Adolescent↗
PubMed1990

[Diphtheria antitoxin levels in Japanese adults (10-20 years after the last vaccination)].

The serum diphtheria antitoxin levels in Japanese adults were investigated and the persistence of diphtheria toxoid effect was evaluated. The subjects consisted of 56 volunteers (20-31 years of age) who had received regular inoculations of diphtheria and pertussis vaccine (I and II or III phases). They had been immunized according to the Vaccination Law (old version) revised in 1958. The length of time after the last inoculation of diphtheria toxoid was speculated to range from 10 to 20 years. Serum diphtheria antitoxin was determined by passive hemagglutination method. Antitoxin level was 0.025 HAU/ml in 1 subject (1.8%), 0.05 in 2 (3.6%), 0.1 in 2 (3.6%), 0.2 in 8 (14.3%), 0.4 in 7 (12.5%), 0.8 in 12 (21.4%), 1.6 in 7 (12.5%) and more than 1.6 in 17 (30.4%). Results indicated that 55 of 56 (98.2%) possessed a higher level than the prophylaxis standard (0.05 HAU/ml). Since the current Vaccination Law prescribes a lower amount and fewer inoculations than the old law, the number of adults possessing prophylactic antitoxin level may decrease in the future. Further investigation of antitoxin level in adults needs to be continued.

Adult↗
PubMed1990

Renal pathology in owl monkeys in Plasmodium falciparum vaccine trials.

Renal specimens of 16 owl monkeys (Aotus vociferans) were studied by light microscopy and immunohistochemistry during a vaccine trial with recombinant proteins of the ring-infected erythrocyte surface antigen (RESA) of Plasmodium falciparum. Deposition of IgG, C3, and P. falciparum antigens in the mesangium was demonstrated by the peroxidase anti-peroxidase (PAP) method. A relationship between the severity of parasitemia at the time of death and the presence of nephropathy was not apparent.

Animals↗
PubMed1990

The pathology of human cerebral malaria.

Blockage of the cerebral microvasculature by Plasmodium falciparum-infected erythrocytes appears to be the principal cause of human cerebral malaria. Knobs which appear on the membrane of the infected erythrocytes adhere to the endothelium, causing the obstruction of cerebral microvessels. Protein molecules such as CD36, thrombospondin, and intercellular adhesion molecule-1, which are present on the membrane of endothelial cells, may act as receptors for the attachment of knobs of P. falciparum-infected erythrocytes. Each of these candidate host molecules for infected-cell recognition and attachment are expressed in microvessels of the human brain. The presence of HRP1 and HRP2 in the cerebral microvessels of cerebral malaria patients may indicate the involvement of knob proteins in the pathogenesis of cerebral malaria. Owl monkeys infected with P. falciparum do not develop cerebral malaria. There is no blockage of cerebral microvessels by infected erythrocytes and knob proteins are absent. These findings support the contention that cerebral microvessel blockage and the presence of knob proteins are the probable causes of cerebral malaria.

Animals↗
PubMed1989

Infectivity of Cryptosporidium muris (strain RN 66) in various laboratory animals.

The infectivity of Cryptosporidium muris (strain RN 66), originally isolated from the house rat (Iseki 1986), to various laboratory animals was studied by transmission experiments. After oral inoculation with 1 x 10(6) oocysts, mice, guinea pigs, rabbits, dogs, and cats all discharged endogenously produced oocysts in their feces. Among these host species, mice and cats were highly susceptible to the parasite. The prepatent period for six 3-week-old specific pathogen-free (SPF) mice was 5 days postinoculation (PI), the patent periods varied between 34 and 75 days for each mouse, and the number of oocysts discharged per individual per day (OPD) was 11-46 x 10(6) at the maximum on days 16-26 PI. The total number of oocysts discharged per mouse during the patent period was estimated to be 170-560 x 10(6). Three inoculated cats (1-2 months old) also discharged a large number of oocysts for a long period. Guinea pigs, rabbits, and dogs showed low susceptibility to this strain; the OPD was extremely small and the patent periods were less than 3 weeks. The entire endogenous development of this parasite occurred in the stomach and not in the small and large intestines of these experimental animals. Because of this lack of host specificity, it is suspected that C. muris could be infective to humans, especially immunocompromised patients such as those with AIDS.

Animals↗
PubMed1989

[Effects of transfer factor on chronic hepatitis B in childhood].

Nine children, 1 to 13 years of age, with HBeAg positive chronic hepatitis B received transfer factor (T.F.) monotherapy for 3 to 17 months, and were monitored by check-ups every six months from serum HBeAg, anti-HBe and GPT. In 12 months, 4 subjects became HBeAg negative and had normal serum GPT. In 22 to 48 months, 6 of the nine subjects had negative HBeAg and normal GPT, 2 had positive HBeAg and high GPT values. The remaining 1 subject who was observed for six months after T.F. therapy remained HBeAg positive with a high GPT values. No side effects were observed. These preliminary observations may indicate beneficial effects of T.F. on the natural course of chronic hepatitis B in childhood, though the ultimate effects awaits longer and well controlled clinical trials.

Adolescent↗
PubMed1988

[A clinicopathological study of mediastinal tumors].

One hundred and fifty-eight cases of mediastinal tumors have been studied clinicopathologically, based on patients of Nagasaki University Hospital from 1961 to 1984. Of these tumors, 29.7% were thymic tumors, 23.4% neurogenic tumors, and 21.5% were germ cell tumors, the frequencies of which reflected the same tendency as other such reports in Japan. Thirty-three cases were malignant tumors. Among them, thymomas were the most common (48.5%) as Wada et al. have reported. Extrathoracic metastases have observed in 2 thymomas. Thymomas associated with myasthenia gravis were seen in 6 cases in which 5 patients are still alive.

Adolescent↗
PubMed1987

Ultrastructure of Cryptosporidium muris (strain RN 66) parasitizing the murine stomach.

The ultrastructure of Cryptosporidium muris, which parasitizes the stomach of mice, was studied by transmission electron microscopy. The entire development of the parasite occurred in the microvilli of the surface mucus cells in the gastric glands. The ultrastructural features of the attachment site of C. muris to the host cell differed remarkably from those of C. parvum and its closely related species, which parasitize the intestine of various animals. The size of C. muris was greater at almost every developmental stage than that of C. parvum. These findings confirmed that C. muris and C. parvum are distinct species. The mitochondria, subpellicular microtubules, and Golgi complex were demonstrated in detail. A small invagination in the meront and intravacuolar tubules were found in Cryptosporidium. The wall of each developing oocyst in the parasitophorous vacuole was composed of three layers: the outermost layer was considered to be a true oocyst wall, whereas the middle and innermost layers were assumed to develop into the sporocyst wall. The outermost layer was fragile and disintegrated as the oocyst matured. In excystation in vitro, a suture was seen in a thick layer of the two-layered sporocyst wall of an oocyst (sporocyst wall; see Discussion) that enveloped four sporozoites. The fine structure of the attachment site of the present species to the host cell appears to reveal a unique mode of host-parasite interaction in Cryptosporidium infection.

Animals↗
PubMed1987

Simple and rapid staining for detection of Entamoeba cysts and other protozoans with fluorochromes.

Three fluorochromes were applied to stain various parasitic protozoans. By double staining with 4',6-diamidino-2-phenylindole and propidium iodide, differentiation of the nuclei from the cytoplasm can easily be achieved within several seconds. The chromatoid bodies in Entamoeba cysts were stained bright red. Plasmodium yoelii at all stages except late trophozoites and young gametocytes was easily identified. In the oocysts of Cryptosporidium sp., the nuclei and cytoplasm of the sporozoites fluoresced bluish white and red, respectively, whereas the residual body appeared blue or green. The third fluorochrome, Calcofluor white M2R, was suitable for detecting the cysts of Entamoeba spp. and Chilomastix mesnili.

Entamoeba↗
PubMed1986

Alpha-fetoprotein-producing pancreatoblastoma. A case report.

A case of pancreatoblastoma, arising in the tail of the pancreas with metastases to the right radius, in an 8-year-old boy is reported. The serum alpha-fetoprotein (AFP) level was over 13 times the normal value before surgery, but returned to normal after removal of the primary tumor. Furthermore, AFP was detected in tumor tissue by immunohistochemistry. This case, representing the second primary non-germ cell pancreatic neoplasm in a child producing elevated serum AFP, supports the use of serum AFP in diagnosing this lesion.

Child↗