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Biomedical subjects

S Song

Publications and source records attributed to S Song.

At least 253 records · Page 14Linked to original sources
PubMed1990

Cat-P300 present after association cortex ablation.

The cat-P300 is a positive endogenous potential, larger to a stimulus when rare than when frequent, with a latency of 200-500 msec. The role of polysensory association cortex, postulated to be important in human P300 generation, was assessed in the cat. EEG was recorded in 13 awake cats from a skull screw at the vertex. Stimuli included frequent (P = 0.80) 1 kHz and rare (P = 0.10) 2 kHz tone pulses with probabilities counterbalanced across 260-trial blocks. After 12 preoperative sessions, bilateral ablations were made of pericruciate cortex (4 cats), anterior lateral and medial suprasylvian gyri (4 cats) and all 3 areas (5 cats). Postoperatively, all 13 cats showed a P300 across 12 recording sessions. Thus polysensory association cortex is not essential for generation of the cat-P300.

Acoustic Stimulation↗
PubMed1990

[Cerebral germinoma].

16 cases of cerebral germinoma are reported. This tumor is comparatively rare. Since it is usually located in pineal and easily be confused with pineloma or ectopic pinealoma, its terminology, source of the tumor tissue, histopathological characteristics, diagnosis and differential diagnosis are discussed by the authors. According to the high mortality of the operative treatment, the radiotherapy is suggested.

Adolescent↗
PubMed1989

Retinoic acid regulation of the expression of retinoic acid receptors in wild-type and mutant embryonal carcinoma cells.

The embryonal carcinoma cell line P19 undergoes terminal differentiation upon induction by retinoic acid (RA). The effects of RA on the retinoic acid receptor (RAR) mRNA level were investigated in P19 cells and an RA non-responsive mutant RAC65. RA induced a rapid accumulation of RAR alpha within 2 h and this was followed by an increase in the RAR beta mRNA. RAC65 cells differed from P19 cells in that the accumulation of RAR alpha mRNA was delayed and that an aberrant pattern of RAR alpha transcript was observed.

Animals↗
PubMed1989

Effect of some oral contraceptives on serum concentrations of sex hormone binding globulin and ceruloplasmin.

Serum SHBG and ceruloplasmin (CP) concentrations were measured in women throughout a cycle of treatment with four oral contraceptives. In women receiving 150 micrograms levonorgestrel (LNG) daily both SHBG and CP decreased. SHBG also decreased, but CP increased, in women receiving ethynyloestradiol (EE) 30 micrograms with LNG 150 micrograms. In women taking 35 micrograms EE with either 600 micrograms or 1000 micrograms norethisterone, increases in CP were similar but SHBG increased more with the lower dose. Serum concentrations had not returned to pretreatment levels by eight days after cessation of dosing. The findings are compared with similar results for women taking 30 micrograms or 50 micrograms EE or an EE,LNG triphasic formulation. Serum concentrations of the gestagens were also measured. Increases in these concentrations when the gestagen was administered with EE to levels higher than expected from administration of the gestagen alone cannot be explained by increased binding to SHBG but are more likely to be due to changes in their metabolism. Differences in the responses of ostensibly closely related proteins of hepatic origin such as SHBG and CP to the oral contraceptives demonstrate that neither can be extrapolated to other pharmacodynamic responses.

Adult↗
PubMed1989

[Cloning and sequence analysis of salmon prolactin cDNA].

A cDNA library was prepared from pacific Chinook Salmon pituitaries. Salmon prolactin gene was screened using synthetic oligonucleotide probes based on partial protein sequence. A positive clone (PRL-10) was identified and sequenced. It is a full size clone containing 1.1 and coding for a preprolactin of 211 amino acids.

Amino Acid Sequence↗
PubMed1989

Determination of the complete nucleotide sequence of HBV adr NC-1 DNA.

On the basis of sequencing the large DNA-fragments which have been inserted into M13mp8, we design a simple strategy to determine the complete nucleotide sequence of HBV adr NC-1 DNA with chain termination method. The whole genome is 3195 nucleotides long. Five reading frames are observed. The gene location and organization are shown.

Base Sequence↗
PubMed1988

Molecular cloning and expression of salmon prolactin cDNA.

Prolactin was purified from chum salmon pituitaries. It was resolved into two variants by reverse-phase high-performance liquid chromatography. A cDNA library was prepared from Pacific chinook salmon pituitaries. Salmon prolactin gene was screened using a synthetic oligonucleotide based on partial protein sequence. A positive clone (PRL-10) was identified and sequenced. It is a full-size clone containing 1.1 kb and coding for a preprolactin of 211 amino acids. A modified prolactin plasmid (PRL-10A), in which the 5' untranslated sequence and the nucleotide sequence coding for the signal peptide of prolactin were deleted, was reconstructed into an expression vector using the heat-inducible lambda pL promotor. Mature prolactin, a single polypeptide of 22 kDa, was efficiently expressed in the bacteria at an elevated temperature.

Amino Acid Sequence↗
PubMed1987

Effect of Anordrin on serum levels of sex hormone binding globulin, caeruloplasmin and ovarian function.

Ten doses of 7.5 mg Anordrin were administered on alternate days from day 5 of the menstrual cycle to 20 women. Serum concentrations of both SHBG and CP were significantly increased after the fourth dose but the increases were minor compared to those produced by ethynyloestradiol. Two weeks after stopping Anordrin, serum concentrations of the proteins were still elevated in most women. Ovarian activity was studied in 8 women; serum oestradiol and progesterone concentrations indicated that ovulation occurred at the normal time in three women but was delayed for two weeks or more in the remaining five. The findings suggest that in humans, Anordrin acts as a weak oestrogen and may also have antioestrogenic activity.

Adult↗
PubMed1986

A pharmacokinetic and pharmacodynamic study of a 'visiting pill' containing norethisterone.

The pharmacokinetics and pharmacodynamic effects of two doses of norethisterone (5mg and 3mg) used as a 'visiting pill' were investigated. There were no significant differences in the pharmacokinetics of the two doses except for the peak concentration achieved and the bioavailability as assessed by the area under the serum norethisterone concentration - time curve. Both doses were rapidly absorbed. Pharmacodynamic effects were minor. No change occurred in serum concentrations of total cholesterol, total triglycerides or HDL-cholesterol. The area under the serum glucose concentration--time curve and particularly the area under the serum insulin concentration--time curve were significantly increased as a result of treatment but no change occurred in the serum levels of glycosylated haemoglobin. SHBG concentrations in serum decreased on treatment whereas those of ceruloplasmin increased.

Absorption↗
PubMed1986

A cavernous sinus cavernous hemangioma. Case report.

The case of a Turner's syndrome patient with an intracavernous hemangioma is presented. The rarity of this lesion is stressed, as is surgical removal without postoperative deficit, the role of estrogens in the pathogenesis, and the clinical and radiological findings.

Adolescent↗
PubMed1984

Sudden death in a patient with Von Recklinghausen's neurofibromatosis.

Sudden death caused by tumors is uncommon. Death attributable to an unsuspected primary intracranial neoplasm is especially rare. An undiagnosed brain tumor is particularly unusual in a patient with Von Recklinghausen's neurofibromatosis (NF). A young man with known NF, with no manifest central nervous system involvement, died less than 24 hours after plastic surgery. A glioblastoma multiforme was discovered at autopsy.

Adolescent↗
PubMedDate not supplied

Peritoneal lymphomatosis: CT findings.

BACKGROUND: Diffuse peritoneal tumor infiltration is well recognized on computed tomography (CT) and is usually associated with carcinomatosis. The purpose of this investigation was to analyze the CT findings of peritoneal spread from primary gastrointestinal lymphomas. METHODS: Abdominal CT scans in eight patients with peritoneal lymphomatosis were retrospectively reviewed. Patients were 12-75 years old (mean = 48 years); with six patients were male and two were female. Pathologic evidence of primary lymphoma was available by colonoscopic biopsy of the terminal ileum in seven cases and by gastroscopic biopsy of the stomach in one case. All patients had non-Hodgkin's lymphoma. We analyzed CT findings in view of presence or loculation of ascites, abnormal patterns of mesentery and omentum, presence of peritoneal enhancement, presence of low attenuation and location of lymph nodes, and primary gastrointestinal lymphoma. RESULTS: Although ascites was present in all patients, there was no loculation. The involvement of mesentery was present in seven patients, and the stellate pattern was the common type (4/7). The involvement of omentum was present in seven patients, and the common type was omental cake (3/7). Peritoneal enhancement was present in six patients. Enlarged lymph nodes were present in six patients, mainly at the retroperitoneum and mesentery, and showed centrally low attenuation in half the patients. CONCLUSION: Patterns of tumor involvement of mesentery, omentum, and peritoneum seen in peritoneal lymphomatosis are indistinguishable from those seen in peritoneal carcinomatosis or tuberculous peritonitis. However, ascites without any loculation or septation and diffuse distribution of enlarged lymph nodes were helpful signs of peritoneal lymphomatosis.

Adolescent↗
PubMedDate not supplied

Attenuation of age-dependent oxidative damage to DNA and protein in brainstem of Tg Cu/Zn SOD mice.

Age-dependent accumulation of oxidative DNA and protein damage in brainstem and striatum was assessed in normal and transgenic (tg) mice which overexpress human Cu/Zn superoxide dismutase (h-SOD1). A marker of oxidative DNA damage, 8-hydroxy-2'-deoxyguanosine (oxo8dG), was measured at 3, 12, and 18 months of age in control and tg mice. Cu/Zn SOD, but not MnSOD, activities in brainstems and striata from tg mice were increased compared to controls at all ages. At 18 months, oxo8dG levels were increased by 58% in brainstem and by 21% in striatum of control mice. In the tg mice, brainstem and striatal oxo8dG levels were increased to a lesser extent than in the corresponding controls. Protein oxidation (carbonyl content), was increased by 59% at 18 months in control brainstem, but not in striatum, and the increase was significantly attenuated in the tg mice. In summary, oxidative damage to DNA and protein increased with age in brainstem (and to a lesser extent in striatum), and augmented Cu/Zn SOD activity modified the extent of DNA and protein damage.

8-Hydroxy-2'-Deoxyguanosine↗
PubMedDate not supplied

Provocation of nonepileptic seizures by suggestion in a general seizure population.

Nonepileptic seizures (NES) are common and are often diagnosed at epilepsy centers by video-EEG recording of both spontaneous and suggestion-induced episodes, but no study has evaluated provocative testing in a general seizure population. We studied consecutive patients with a tentative diagnosis of epilepsy using saline provocation during video-EEG recording, suggesting that this could produce a typical seizure. Of 52 patients, 40% had no response, 23% had responses unlike their seizures, and 37% had typical episodes (positive test). Patients whose usual episodes resembled complex partial seizures (CPS) were more likely to have NES than were patients with a history of generalized tonic-clonic seizures (GTC). Of patients with positive provocations, the primary physician predicted NES in 68% of cases. This preliminary study suggests that NES are frequent in a general neurology setting, and that saline provocation is a sensitive method of identifying NES.

Adult↗