Chemiluminescence-high-performance liquid chromatographic determination of tea catechin, (-)-epigallocatechin 3-gallate, at picomole levels in rat and human plasma

A method of chemiluminescence detection-high-performance liquid chromatography (CL-HPLC) for the highly specific determination of tea catechin, (-)-epigallocatechin 3-gallate (EGCg), present in rat and human plasma has been newly developed. The CL-HPLC system consists of reversed-phase HPLC and chemiluminescence detector, in which separated EGCg generates chemiluminescence at post column successively reacting with the following two chemiluminescence cocktails; 8.2 M acetaldehyde in 50 mM phosphate buffer (pH 7.4, contained 108 mg horseradish peroxidase/L) and 8.8 M hydrogen peroxide aqueous solution. The plasma EGCg was extracted by methanol. This method enables the detection of EGCg in the free form selectively at as low as 2 pmol with recovery of 84%. The EGCg concentration in fasted rat plasma was initially below the detection limit (< 2 pmol/ml), but increased to maximum level (2284 pmol/ml plasma, 1047 ng/ml; calculated 0.012% of ingested EGCg) 30 min after a single oral supplementation of 56 mg EGCg per rat. The EGCg concentration in fasted human plasma was also initially below the detection limit and increased to 341 pmol/ml (156 ng/ml; calculated 0.32% of ingested EGCg) at 60 min after a single oral intake of 97 mg EGCg per subject. The results indicated that tea catechin, EGCg, is absorbed from the digestive tract into the rat and human body and that the CL-HPLC method reported here should be a powerful tool for studying the metabolic fate and bioavailability of EGCg.

Superparamagnetic iron oxide enhanced magnetic resonance imaging of rat liver with hepatocellular carcinoma and benign hyperplastic nodule

RATIONALE AND OBJECTIVES

The authors assess the potential of a new superparamagnetic iron oxide (SPIO) in grading hepatocellular carcinoma (HCC) histologically and in differentiating HCC from benign hyperplastic nodule (HPN).

METHODS

Nine Wistar rats (with poorly to moderately differentiated HCC, well-differentiated HCC, and HPN) received drinking water containing N-nitrosomorpholine, and were examined by magnetic resonance imaging (4.7 tesla). Spin-echo images (repetition time/echo time, 600/24.5 mseconds) were obtained before and 15 minutes after intravenous administration of 10 mumol Fe/kg of SH U 555A.

RESULTS

Poorly to moderately differentiated and well-differentiated HCC showed no significant change in signal-to-noise ratio (SNR) 15 minutes after contrast, whereas HPN showed a significant decrease in SNR. The contrast-to-noise ratio (CNR) between each kind of tumor and adjacent liver parenchyma showed a significant increase at 15 minutes after contrast.

CONCLUSIONS

The SPIO discussed in this article may help to differentiate HCC from HPN, but it remains difficult to grade hepatocellular carcinoma histologically.

A rat model of spontaneously arrested hydrocephalus. A behavioural study

HTX rats with congenital hydrocephalus that survived for more than 2 months are termed spontaneously arrested hydrocephalic rats. These rats showed impairment in learning, a reverse light-dark discrimination task in a Y-maze. A clear relationship between learning impairment and ventricular dilatation was observed in spontaneously arrested hydrocephalic animals. The usefulness and limitations of HTX-rats as an animal model of spontaneously arrested hydrocephalus are discussed.

[Synthesis and antibacterial properties of pyrido[2,3-b]pyrazine derivatives]

Novel pyrido[2,3-b]pyrazine 1,4-dioxide and pyrido [2,3-b]pyrazine 1-oxide derivatives were synthesized from furazano [4,5-b]pyridine 3-oxide and the enolic form of 1,3-diketones or beta-ketoesters catalyzed by silica gel or molecular sieves. Their antibacterial activities were evaluated. As the results of anti-bacterial screening tests in vitro, pyrido[2,3-b]pyrazine 1,4-dioxide derivatives revealed strong activities, but pyrido[2,3-b]pyrazine 1-oxide derivatives revealed no activities.

Intraischemic hypothermia during pretreatment with sublethal ischemia reduces the induction of ischemic tolerance in the gerbil hippocampus

We examined whether mild brain hypothermia during pretreatment with sublethal 2-min ischemia affected the tolerance to subsequent lethal 5-min ischemia. The neuronal densities in the hippocampal CA1 sector of gerbils preconditioned at mild brain hypothermia (32% of normal) were significantly lower than those in gerbils preconditioned at brain normothermia (70% of normal). 72-kDa heat-shock protein immunoreactivity in the CA1 sector preconditioned at mild hypothermia was reduced. These results suggests that mild brain hypothermia during pretreatment with sublethal ischemia reduces the tolerance to subsequent lethal ischemia.

Replication of feline syncytial virus in feline T-lymphoblastoid cells and induction of apoptosis in the cells

Feline syncytial virus (FSV) was isolated from feline peripheral blood mononuclear cells of FSV-seropositive cats. When the susceptibility of feline T-lymphocytes to FSV was examined using three strains of FSV, FSV antigens were detected in the FSV-infected T-lymphoblastoid cells. Further, a diversity of biological properties, including replication kinetics and syncytia formation, was noted among the strains, and condensation of chromatin and the fragmentation of cellular DNA were observed in the infected cells. From these data, we conclude that FSV is lymphotropic and can induce apoptosis in the lymphocytes.

Feline leukaemia virus proviral DNA detected by polymerase chain reaction in antigenaemic but non-viraemic ('discordant') cats

A nested polymerase chain reaction (PCR) was established to detect exogenous feline leukaemia virus (FeLV) proviral DNA in feline peripheral blood leukocytes (PBL). The assay detected a single copy of plasmid DNA of an infectious molecular clone of FeLV subgroup A in the sample by ethidium bromide staining in agarose gels. The utility of the nested PCR in the diagnosis of FeLV infections was compared with the detection of FeLV p27 antigen by enzyme-linked immunosorbent assay (ELISA) and virus isolation (VI). FeLV genomes were detected by PCR in all 4 samples that were positive by ELISA and VI but in none of 7 samples that were negative by the two methods. FeLV genomes were found by PCR in 13 of 39 samples from cats that were antigenaemic but from which no virus was isolated ('discordant' cats). These results demonstrated that a proportion of discordant cats harboured FeLV genome in their PBL.

[A case of jugular foramen neurinoma originating from glossopharyngeal nerve]

A 39-year-old man was admitted with right hearing loss, tinnitus and vertigo. Neurological examination on admission revealed right facial palsy, right acoustic nerve disturbance and cerebellar ataxia. CT scan demonstrated a mass with intra-and extracranial extension in the pyramid bone concomitant with enlarged jugular foramen. MRI showed a ring-like enhanced, extra-axial mass in the right CP angle. Cerebral angiography showed no tumor stain. Venous phase of VAG revealed lateral displacement of the right sigmoidal sinus and obstruction of the internal jugular vein. Three dimensional CT was very useful to reveal enlarged jugular foramen. The tumor was resected totally and was approached through a right suboccipital craniectomy and mastoidectomy on July, 1994. Surgery confirmed that the tumor was a neurinoma originating from the glossopharyngeal nerve. After the operation, right facial palsy developed and transient fugitive CSF leakage was observed, but the patient is doing well. There was no amelioration of right hearing loss. JFN originating from the glossopharyngeal nerve is rare. Twenty-five cases of glossopharyngeal neurinoma are reviewed.

Phylogenetic analysis of feline immunodeficiency virus isolated from cats in Taiwan

Feline immunodeficiency virus was isolated from four cats in Taiwan. The isolates were designated TI-1, TI-2, TI-3 and TI-4. Each was isolated from PBMCs following co-cultivation of PBMCs with a feline T-lymphoblastoid cell line (MYA-1 cells). However, the Taiwanese isolates did not grow in a feline kidney cell line (CRFK cells). The nucleotide sequences of the V3-V5 region of the envelope gene of the Taiwanese isolates were determined and compared with those of previously described isolates. Phylogenetic analysis of this region indicates that Taiwanese isolates belong to subtype C.

Roles of the auxiliary genes and AP-1 binding site in the long terminal repeat of feline immunodeficiency virus in the early stage of infection in cats

To examine the roles of auxiliary genes and the AP-1 binding site in the long terminal repeat of feline immunodeficiency virus (FIV) in vivo, three mutant viruses, which are defective in the vif gene ([delta]vif), ORF-A gene (deltaORF-A), and AP-1 binding site (deltaAP-1), and wild-type virus as a positive control were separately inoculated into three specific-pathogen-free cats. These cats were assessed by measuring the number of proviral DNA copies in peripheral blood mononuclear cells (PBMCs), the CD4/CD8 ratio and antibody responses to FIV for 16 weeks and then examining histological changes at necropsy. Although viral DNAs were detected in PBMCs from all 12 cats to various degrees until 16 weeks postinoculation, no virus was recovered from PBMCs of cats infected with (delta)vif virus during the observation period. However, a very weak antibody response was induced in one cat infected with the (delta)vif virus. In contrast, despite the successful recovery of virus from both groups of cats infected with deltaORF-A and deltaAP-1 virus, antibody responses and decrease in the CD4/CD8 ratio in the groups were milder than those in cats infected with wild-type virus. Furthermore, the numbers of proviral DNA copies in PBMCs from the two groups were not able to reach the level in cats infected with wild-type virus during the observation period. From these results, we conclude that these mutant viruses are still infectious for cats but failed in efficient viral replication and suggest that these auxiliary genes and enhancer element are important or essential to full viral replication kinetics and presumably to full pathogenicity during the early stage of infection in vivo.

Repeated hyperbaric oxygen induces ischemic tolerance in gerbil hippocampus

Hyperbaric oxygen (HBO; 100% oxygen at 2 atmospheres absolute) was administered for 1 h to male Mongolian gerbils either for a single session or every other day for five sessions. Two days after HBO pretreatment, the gerbils were subjected to 5 min of forebrain ischemia by occlusion of both common carotid arteries under anesthesia. Seven days after recirculation, neuronal density per 1-mm length of the CA1 sector in the hippocampus was significantly better preserved in the five-session HBO pretreatment group (n = 10: 175.7 (47.8/mm, 54.9% of normal) than in the ischemic control group (n = 10: 26.2 (11.6/mm, 8.0% of normal) and in the single-session HBO pretreatment group (n = 7: 37.3 (21.7/mm, 11.4% of normal). Immunohistochemical staining for the 72-kDa heat-shock protein (HSP-72) in the CA1 sector performed 2 days following pretreatment revealed that the five-session HBO pretreatment increased the amount of HSP-72 present compared with that in the ischemic control group and in the single HBO pretreatment group. These results suggest that tolerance against ischemic neuronal damage was induced by repeated HBO pretreatment, which is thought to occur through the induction of HSP-72 synthesis.

Pontine glioma with osteoblastic skeletal metastases in a child

BACKGROUND

The development of systemic metastases from primary intracranial gliomas is rare. We report here a rare case of pontine glioma with osteoblastic skeletal metastases.

CASE

This 12-year-old boy presented with a 4-month history of hoarseness, dysphagia, and a progressively ataxic gait. Cranial computed tomography (CT) and magnetic resonance imaging (MRI) revealed a brain stem tumor that was diagnosed as a low grade glioma by stereotactic biopsy. Twelve months later following chemotherapy and radiotherapy, neurologic examination and neuroradiologic studies disclosed a recurrence of the pontine glioma. Skeletal roentgenograms revealed widespread osteoblastic metastases in the skull, vertebral bodies, pelvis, and long bones. A specimen from the iliac bone demonstrated cells that were immunoreactive glial fibrillary acidic protein (GFAP).

DISCUSSION

The mechanism of how glioma cells determine their biologic behavior at bony metastatic sites is not known. Infratentorial gliomas, which occur frequently in young patients and demonstrate active bony metabolism, may stimulate osteoblastic cells, and induce osteoblastic changes.

HLA associations in otosclerosis in Japanese patients

Otosclerosis is a disease of the otic capsule that is caused by abnormal resorption and redeposition of bony tissue. Sixty-two unrelated Japanese patients exhibiting clinical otosclerosis were typed for HLA-A, -B, -C antigens. Twenty-one of the patients were also typed for DR antigens. The frequency of HLA-Aw33 was significantly higher in otosclerosis patients than in the control group (24.2% vs 9.5%). This finding suggests that the presence of HLA-Aw33 antigens may be related to an increased susceptibility to otosclerosis or to its clinical outcome.

Eustachian tube function and middle ear barotrauma associated with extremes in atmospheric pressure

Eustachian tube (ET) function was studied by means of sonotubometry and tubotympano-aerodynamography (TTAG) prior to and following exposure to hypobaric or hyperbaric conditions. Forty normal adults were subjected to hypobaric pressure. Fifty adults who underwent hyperbaric oxygen (HBO) therapy also were studied. Following hypobaric exposure, 14 of 80 ears (17.5%) exhibited middle ear barotrauma. Following hyperbaric exposure, 34 of 100 ears (34%) exhibited middle ear barotrauma. Dysfunction of the ET, characterized by altered active and passive opening capacity, was more prevalent following exposure to extremes in atmospheric pressure compared to baseline. The ET function, which was impaired after the first HBO treatment, improved gradually over the next 2 hours. Overall, however, ET function was worse after the seventh treatment. The patients who developed barotrauma exhibited worse ET function prior to hypobaric or hyperbaric exposure. Thus, abnormal ET function can be used to predict middle ear barotrauma prior to exposure to hypobaric or hyperbaric atmospheric pressure.

Stapes fixation associated with symphalangia

We describe a 10-year-old boy and his 9-year-old sister, both of whom had bilateral hearing loss associated with ankylosis of the proximal interphalangeal joints (symphalangia). They had no other abnormal findings except hearing loss and ankylosis of the joints of some fingers and toes on systemic examination. The cause of conductive hearing loss in both cases was bony fusion between the stapes and the bone of the oval window niche. There were no other anatomical abnormalities in the middle or the external ear. The patients' hearing improved markedly after stapes surgery. Histopathologic examination of the stapes revealed an abnormal zone of ossification near the anterior annular ligament and calcification in the annular ligament, which seemed to be the cause of the stapes fixation.

[Effect of heparin-supplemented iopamidol on the blood coagulation]

The purpose of the study was to determine the concentration of heparin to be added to iopamidol in order to assure adequate anticoagulant activity and tolerability. Iopamidol that contained heparin at a concentration of 3 U/ml showed the anticoagulant activity similar to ionic contrast agents, while maintaining excellent tolerability.

Persistence of high virus neutralizing antibody titers in cats experimentally infected with feline immunodeficiency virus

The development of virus neutralizing (VN) antibody is one of the most effective host defense mechanisms against virus infection. In the present study, we developed a new VN assay against feline immunodeficiency virus (FIV) using a feline T-lymphoblastoid cell line, MYA-1 cells, based on inhibition of viral reverse transcriptase production. This assay is applicable to strains of FIV which can not infect CRFK cells. By using the assay, we examined long-term responses of VN antibody in cats experimentally infected with FIV. VN antibody titers increased progressively during first 30 weeks post inoculation and remained at high titers thereafter for 7 years of observation periods.

[The epidemiology of nontuberculous mycobacterial diseases in Hiroshima Prefecture]

The patients of diseases caused by nontuberculous mycobacteria (NTM) newly diagnosed in 1993 in Hiroshima Prefecture were investigated retrospectively. During 1993, 59 newly diagnosed patients of NTM disease, who were the resident of Hiroshima Prefecture were reported from 6 hospitals. Mycobacterium avium complex (MAC) disease was most frequent (53 patients, 90%) and M. kansaii (MK) disease, which accounts for more than 20 percent of all the NTM diseases in the national survey of Japan, was found only in 3%. Other pathogenesis were M. chelonae and M. fortuitum. Incidence rate for all NTM disease per 10(5) population was 2.1. Age-specific incidence rate calculated from the estimated population of Hiroshima Prefecture was; less than 0.4/10(5) under the age 40, 4.0/10(5) in the age group 50 to 59, 4.5/10(5) in the age group 60 to 69 and 9.4/10(5) in the age group over 70. Thirty-one patients (57%) had underlying pulmonary disease such as previous lung tuberculosis (TB) and previous history of TB was found in 41 percent of patients over 60 yr. of age. The data suggest that epidemiological picture of NTM diseases may change in the future. Relative increase of elder population will lead to the increase of NTM diseases as a whole; the incidence rate calculated from the age specific incidence rate and predicted population of Japan in 2025 is 3.1/10(5), which is 1.5 fold higher than the present rate. However, secondary NTM diseases with healed TB will decrease because of the sharp decline of TB morbidity in Japan. Assuming that secondary NTM disease with healed TB decreases to one-fourth, estimated incidence rate will be 2.3. Further, the upward tend of MK disease in Japan should be taken into consideration. Thus, the future trends of NTM diseases will increase fairly due to the increase of elder population as well as the MK disease. It was pointed out that many NTM disease cases had been counted as tuberculosis in the surveillance system of Japan. In our present study, 52 (82%) were registered as tuberculosis in the beginning and only 19 cases were reported later to health centers as NTM disease. As tuberculosis classification and surveillance system in Japan were changed from 1996 to separate NTM disease from TB, NTM disease cases will be counted separately in the tuberculosis statistics. This revision in the management of NTM disease should be taken into account when discussing the trend of tuberculosis statistics in Japan.

Genetic diversity of Argentine isolates of feline immunodeficiency virus

We report the nucleotide sequence and genetic diversity of part of the envelope (env) gene of four strains of feline immunodeficiency virus (FIV) isolated from Argentine domestic cats. The DNA encoding the V3 to V5 regions of the env gene of the FIV isolates were amplified by PCR, cloned and sequenced. Phylogenetic analysis revealed that the Argentine isolates did not cluster into a single group; one isolate clustered with subtype B FIV isolated in the USA and Japan, whereas the others formed a new cluster of FIV which might represent a prototype sequence for subtype E.

Feline immunodeficiency virus can infect a human cell line (MOLT-4) but establishes a state of latency in the cells

Infectivity of feline immunodeficiency virus (FIV) in feline and human lymphoblastoid cell lines was examined using homogeneous populations of FIV derived from infectious molecular clones of strains TMZ and Petaluma, and two recombinant chimeric clones carrying gag, pol, vif and ORF-A from the heterologous virus. FIV from the clones with the env region of the Petaluma strain was shown to infect and establish provirus in a human lymphoid cell line (MOLT-4), although the FIV-infected cells did not produce any infectious viruses. By treatment of the infected MOLT-4 cells with a phorbol ester, infectious virus was rescued. To examine which stage of the life-cycle of FIV is blocked in these cells, we analysed transcription of FIV-14 in the cells by RT-PCR. FIV-specific RNA expression could not be detected. These results strongly suggest that latency of the virus in MOLT-4 cells is due to a failure in transcription.

Inhibition of mucosal lipid hyperoxidation by green tea extract in 1,2-dimethylhydrazine-induced rat colonic carcinogenesis

Phosphatidylcholine hydroperoxide (PCOOH) measured using a chemiluminescence detector to examine colonic mucosal lipid hyperoxidation increased after injection of 1,2-dimethylhydrazine and green tea extract (GTE), which we previously showed inhibited carcinogenesis and oxidative DNA damage in the gastrointestinal tract. Therefore, the hyperoxidation of membrane phospholipids reflected well the degree of DNA damage and carcinogenic alteration, and may be a useful intermediate biomarker for initiation of carcinogenesis.

[Successful treatment of pulmonary alveolar proteinosis by massive bronchoalveolar lavage]

In two patients with pulmonary alveolar proteinosis, PaO2 was normalized by massive bronchoalveolar lavage (BAL). Patient 1: A 29-year-old man presented with exertional dyspnea and a PaO2 of 57.8 mmHg. After four BALs, the PaO2 was 106.4 mmHg. For ten years thereafter he has been doing well. Patient 2: A 58-year-old women presented with extertional dyspnea and a PaO2 of 64.4 mmHg. The PaO2 increased to 110.6 mmHg after four BALs. BAL required much skill, but it is one of the most effective methods for the treatment of pulmonary alveolar proteinosis. Because this condition is related to an interstitial process, these two patients need to be followed carefully.