Biomedical subjects

X Xie

Publications and source records attributed to X Xie.

227 records · Page 13Linked to original sources

PubMed1990

[Studies on the assimilation of inorganic selenium by yeast].

In the process of assimilation of inorganic selenium by yeast to the organic-selenium, some rules on the relation of the kinds of culture medium, concentration of sodium selenite and methionine to the total selenium and selenomethionine content in the yeast formed have been found; and a new, accurate procedure--modified acid hydrolysis-ion exchange chromatography for determining the content of seleno-amino acid in biological materials has been established.

Culture Media↗

PubMed1990

[An immunologic study of patients with epilepsy].

Eight indices of the immunological function were studied in 246 adult epileptic patients with 100 normal adults as control, it was found that mean contents of blood IgA, and IgM decreased, that of complement C3 increased, and the rates of lymphocyte transformation as well as rosette formation decreased in this group of epileptic patients. The decrease of IgA was related to the types of seizures and the taking of antiepileptic drugs. Suggesting that immunological abnormality did exist in the epileptic patients. The mean content of circulating immune complexes. (CIC) had a negative correlation with the period of time after seizures. It was much higher than that of the controls within the first 3 days after the seizures with its highest levels reached on the first day. Suggesting that immune reactions took part in the process of seizure episodes.

Adolescent↗

PubMed1990

[The X-ray characteristic feature of the multiple primary malignant tumor of digestive tract].

A study on the multiple primary malignant tumor of digestive tract (MPMTDT) was made in the period of 1984-1988 in our hospital. Twenty five cases are reported in this paper. All of them were examined by X-ray, endoscopy, and proved to be MPMTDT by surgery and pathological examination. Twenty three cases were double primary tumors and 2 cases triple primary malignant tumors. The characteristic X-ray feature of the site of predilection and manifestation in primordial period of MPMTDT are described in this paper. These criteria are important for the early detection and selection of treatment of the tumors.

Adenocarcinoma↗

PubMedDate not supplied

Phase relationship between ocular and behavioral circadian rhythms in Bulla gouldiana exposed to different photoperiods.

To determine whether the ocular circadian pacemakers of the marine snail Bulla gouldiana exert phase control over the circadian rhythm in locomotor activity, we measured the phase angles for entrainment of the ocular pacemakers and the activity rhythm on four different photoperiods: L:D 15:9, 12:12, 9:15, and 4:20. We found that the phase angle for ocular entrainment was progressively advanced relative to dawn as photoperiod decreased, although the phase was fixed relative to the middle of the day. In contrast, activity began near dusk on all photoperiods. On subsequent release into constant conditions, the free-running locomotor activity commenced near the time of previous activity onset. Thus, activity phase on light cycles represents the entrainment of a light sensitive pacemaker. The resulting lability in phase between ocular and behavioral rhythms in Bulla exposed to light cycles suggests that the ocular pacemakers are not the only determinants of locomotor activity phase in Bulla.

Animals↗

PubMedDate not supplied

Left ventricular diastolic function in young adults: the Coronary Artery Risk Development in Young Adults Study.

Doppler transmitral flow velocities have been used to assess left ventricular diastolic function. Associations of transmitral velocities with specific physiologic variables and cardiovascular risk factors have not been reported previously in a large population-based study of young adults. We performed Doppler analysis of left ventricular inflow in 3492 black and white men and women (aged 23 to 35 years) in the year-5 examination of the Coronary Artery Risk Development in Young Adults (CARDIA) Study. First third filling fraction, peak flow velocity in early diastole (PFVE), peak flow velocity in late diastole (PFVA), and the PFVA/PFVE ratio were measured. Women had higher PFVE and PFVA than had men (PFVE: 0.81 +/- 0.13 m/sec versus 0.76 +/- 0.13 m/sec; PFVA: 0.47 +/- 0.11 m/sec versus 0.43 +/- 0.10 m/sec; both p < 0.001). Gender-specific multiple regression analyses showed that age, heart rate, systolic blood pressure, left ventricular percent fractional shortening, and body weight were independently and positively related to PFVA (all p < 0.001) in men and women. Age, heart rate, and forced expiratory lung capacity in 1 second were inversely related to PFVE and first third filling fraction (both p < 0.01). Left ventricular percent fractional shortening was positively related to PFVE and first third filling fraction (p < 0.001). Age, heart rate, and body weight were positively correlated with the PFVA/PFVE ratio (all p < 0.001). Height had weak negative associations with PFVA and PFVE in women only. These results suggest that, in young adults, Doppler measures of left ventricular diastolic filling are related to age, sex, body weight, blood pressure, heart rate, left ventricular systolic function, and lung function.

Adult↗

PubMedDate not supplied

Regression of colon cancer and induction of antitumor immunity by intratumoral injection of adenovirus expressing interleukin-12.

Interleukin-12 (IL-12) has been shown to possess potent immunoregulatory and antitumoral effects. We have evaluated the anti-oncogenic potential and the mechanisms of the antitumoral effect of in vivo adenovirus-mediated transfer of IL-12 gene in a murine model of colon cancer. AdCMVIL-12 was constructed to permit coordinated production of p40 and p35 subunits of IL-12 gene to obtain the maximum IL-12 bioactivity. Infection of murine colon cancer CT-26 cells in vitro with AdCMVIL-12 resulted in the production of high levels of IL-12. In vivo gene therapy of colon cancer nodules by intratumoral injection of AdCMVIL-12 induced a local increase in IL-12 and interferon-gamma levels and a complete regression of the tumor in 26 of 34 (76%) mice. Tumor disappeared between days 7 and 10 after vector administration. The antitumoral effect was mediated by CD8+ T cells and was associated with the generation of cytotoxic T lymphocytes against colon cancer cells. Animals that eliminated the tumor were protected against a second administration of neoplastic cells. Treatment with AdCMVIL-12 of one tumor nodule also caused regression of established tumors at distant sites. These data demonstrate that AdCMVIL-12 is a useful therapeutic tool for established colon cancer in mice and should be considered for application in humans.

Adenoviridae↗

PubMedDate not supplied

Air pollution-type fluorosis in the region of Pingxiang, Jiangxi, Peoples' Republic of China.

This paper reports on the epidemiology, environmental factors, geological features, and total amount of fluoride intake by residents of the Pingxiang region in the Peoples' Republic of China where there is a high incidence of endemic fluorosis. The results demonstrate that the type of endemic fluorosis is related to air pollution, the major source of which comes from coal that is burned by the residents in their homes. Air pollution also originates from the small kilns that are used to make bricks and tile. The fluorine content in the coal and mud used to mix the coal is considerably high; the content in the mud used as adobe for tiles exceeds 10,000 mg/kg. During the process of burning coal or baking bricks or tiles, a large amount of nonsoluble fluorine is converted into water-soluble fluoride, which can have major human health effects.

Adolescent↗

PubMedDate not supplied

Differential expression of short-term potentiation by AMPA and NMDA receptors in dentate gyrus.

Both alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) and N-methyl-D-aspartate (NMDA) glutamatergic receptor subtypes in hippocampus have been shown to express long-term potentiation (LTP), a form of synaptic modification believed to be involved in memory formation. Because of their postsynaptic localization, any differential expression of LTP by the two receptor subtypes would strongly support the existence of a postsynaptic mechanism of LTP expression. In this study, electrophysiological recordings from dentate granule cells were used to compare the potentiation of AMPA and NMDA receptor-mediated responses occurring during the initial phase of LTP, typically identified as STP. Results revealed that high-frequency stimulation (HFS) of perforant path afferents induces a robust STP of both AMPA and NMDA receptor-mediated components of granule cell EPSPs (referred to as AMPA STP and NMDA STP, respectively). Although STP for both receptor subtypes decayed to an asymptotic, steady-state level of LTP and could be induced repetitively, there were substantial differences in several aspects of AMPA and NMDA STP dynamics. STP of the AMPA receptor reached its peak magnitude approximately 30 sec after HFS and decayed with a time constant of approximately 6 min. In contrast, peak magnitude of NMDA STP always appeared immediately after HFS and decayed with a time constant of only 1 min. Single-pulse stimulation of perforant path afferents paired with postsynaptic depolarization also induced LTP of both AMPA and NMDA components. When this induction paradigm was used, however, only the AMPA component showed significant STP. Our results demonstrate that AMPA and NMDA receptors exhibit markedly different degrees of activity-dependent, short-term modifiability, with the possibility that STP of the NMDA receptor reflects primarily post-tetanic potentiation (PTP). In addition, our results strongly suggest that the mechanisms underlying STP of the AMPA receptor are postsynaptic in origin.

Animals↗

PubMedDate not supplied

Extrauterine choriocarcinoma of the greater omentum after tubal pregnancy: case report.

Extrauterine choriocarcinoma is a rare form of gestational trophoblastic tumor. Extrauterine choriocarcinoma of the greater omentum is extremely rare in the literature. A 24-year-old female with irregular vaginal bleeding, mimicking as ectopic pregnancy, underwent emergency exploratory laparotomy and local excision of the greater omentum mass. The serum beta-human chorionic gonadotropin level decreased rapidly after operation; however, it rose up again before long. Pathology showed choriocarcinoma in the greater omentum. No evidence showed lesions on uterus. No other metastasis was found. Multiple courses of combined chemotherapy were effective for this case. Surgical excision and combined chemotherapy were effective for extrauterine choriocarcinoma of the greater omentum.

Adult↗

PubMedDate not supplied

In vivo 31P magnetic resonance spectroscopy and 1H magnetic resonance imaging of human bladder carcinoma on nude mice: effects of tumour growth and treatment with cis-dichloro-diamine platinum.

In vivo 31P NMR spectroscopy and 1H NMR imaging were used to examine the bladder T24B carcinoma in nude mice during untreated growth and in response to chemotherapy by Cis-dichloro-diammine-platinum (CDDP) at a dose of 8 mg/kg i.p. Untreated growth was associated with an increase of inorganic phosphate and phosphomonoesters and a decrease of phosphocreatine. Fast growing tumours and early stage of regrowth after treatment presented a higher phosphocreatine/beta NTP ratio. Following CDDP treatment, 31P metabolite ratios and pH were significantly altered compared with age-matched controls, as early as 6 hours after treatment. Although necrotic area was clearly visible in MRI, no treatment effect could be detected on the images of treated tumours.

Animals↗

PubMedDate not supplied

Kinetics of distribution and adipose tissue storage as a function of lipophilicity and chemical structure. II. Benzodiazepines.

Distribution kinetics of flurazepam, medazepam, prazepam, and clobazam were determined in rats. Concentration-time curves of unchanged drugs and non-polar metabolites in plasma, adipose tissue, liver, brain, and muscle after a single iv administration were obtained using GLC/electron capture detector analysis. Pharmacokinetic parameters were calculated for plasma and tissues. Adipose tissue storage was quantified with the adipose storage index (ASI). Including data of benzodiazepines from the literature, a correlation between ASI and log P (over a range 1.6-3.8) was nonexistent and the influence of individual functional groups was not easily discernible. However, benzodiazepines with a pKa (base) within the range 1.6-6.2 were stored in adipose tissue (ASI greater than 1), whereas those with pKa greater than 7 were not (ASI less than 1). Since many other basic lipophilic drugs with pKa greater than 7 are not stored in adipose tissue, and this is likely due to lysosomal trapping in lean tissues, which requires a pKa value above 7, it is suggested that within the series of benzodiazepines, adipose tissue storage is mainly influenced by the basicity of the drugs.

Adipose Tissue↗