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Biomedical subjects

B He

Publications and source records attributed to B He.

At least 271 records · Page 15Linked to original sources
PubMed1991

[Effect of salt-loading on prostacyclin and thromboxane metabolism in kidney].

For evaluating the role of prostacyclin (PGI2) and thromboxane A2 (TXA2) in the metabolism of salt and water, the metabolic products of PGI2 and TXA2 (6-keto-PGF1 alpha and TXB2 respectively) were measured by radioimmunoassay in salt-loaded rabbits. 36 normal rabbits were randomly divided into 3 groups: 1. normal control group; 2. 3h salt-loading group (3 h group); 3. 24 h salt-loading group (24 h group). Both the 3 h and 24 h groups were given 0.9% NaCl solution by subcutaneous injection to the hind legs. The kidneys were dissected into 4 slices: outer cortex, inner cortex, outer medulla and inner medulla. The plasma 6-keto-PGF1 alpha in the 3 h group was increased from the control value of 46.61 +/- 19.04 pg/ml to 111.63 +/- 58.36 pg/ml (P less than 0.01). All of the dissected renal slices also showed significant increase of 6-keto-PGF1 alpha synthesis in both the 3 h and the 24 h groups (P less than 0.001 vs. normal). The urinary sodium concentrations have a good correlation with 6-keto-PGF1 alpha in plasma or in kidney tissues. Plasma TXB2 in normal group was 499.27 +/- 197.86 pg/ml, but no significant change was found in the 3h group. However, in the 24 h group it decreased significantly to 218.76 +/- 114.54 pg/ml (P less than 0.05 vs. normal group). Although the TXB2 increment was significant only in inner medulla, all other dissected renal slices showed some increase of TXB2 synthesis too. It is concluded that salt-loading can cause increase of PGI1 and TXA2 synthesis in normal renal tissues.(ABSTRACT TRUNCATED AT 250 WORDS)

6-Ketoprostaglandin F1 alpha↗
PubMed1991

[Invasion of human lung adenocarcinoma cell line LTEP-a2 into various organs of different species].

The invasiveness of human lung adenocarcinoma cell line LTEP-a2 was investigated in co-culture system of tumor cells and fragments of the heart and liver from the newborn, rabbit and rat. It was found that the tumor cells had different invasive behaviors, for example cell diastrophism, proliferation or invasion speed and adenic formation when invading various species or various organs in the same species. When invading the fragments of newborn heart and liver, strong cell diastrophism potential, cell twist or formation of multiprocess pseudopodia and mitosis could be observed. The result was contrary to the above when the fragments of rat heart and liver were used as the target. When the fragments of rabbit liver were invaded, marked adenization was formed by cancer cells with the invading speed increased. However, the adenic structure was absent as the heart fragments of rabbit were invaded. The results indicate that target organs could change biological behavior of the invading tumor cells to different degrees even their differentiation. It may be related to structure and biochemical property of the target organs.

Adenocarcinoma↗
PubMed1990

Genes of the Escherichia coli pur regulon are negatively controlled by a repressor-operator interaction.

Fusions of lacZ were constructed to genes in each of the loci involved in de novo synthesis of IMP. The expression of each pur-lacZ fusion was determined in isogenic purR and purR+ strains. These measurements indicated 5- to 17-fold coregulation of genes purF, purHD, purC, purMN, purL, and purEK and thus confirm the existence of a pur regulon. Gene purB, which encodes an enzyme involved in synthesis of IMP and in the AMP branch of the pathway, was not regulated by purR. Each locus of the pur regulon contains a 16-base-pair conserved operator sequence that overlaps with the promoter. The purR product, purine repressor, was shown to bind specifically to each operator. Thus, binding of repressor to each operator of pur regulon genes negatively coregulates expression.

Base Sequence↗
PubMed1990

[Morphological observation of destruction and phagocytosis of the target organs by human lung adenocarcinoma cell line in organ culture].

In a co-culture system of human lung adenocarcinoma cells (LTEP-a2) with tissue fragments of human heart and liver, it was found that the target organs were destroyed with cancer cells invading. The destruction shown as cell swelling, atrophy, fatty degeneration and disappearance of the cardiac muscle streak, myocomma and local cell membrane, always occurred at sites immediately in contact with the invading cancer cells. However, cell changes could develop not in direct contact with tumor cells. The farther invasion by the tumor cells, the more serious destruction was seen. It was also observed that the tumor cytoplasmic processes could surround debris derived from the target tissue and the debris could be found inside cancer cells. The rapidly invading cells contained more phagosomes than the slowly invading ones.

Adenocarcinoma↗
PubMed1989

Effects of cavities on EEG dipole localization and their relations with surface electrode positions.

Effects of cavities in the human head on EEG dipole localization have been investigated by computer simulation. The human head is represented by a homogeneous spherical conductor including an eccentric spherical cavity which approximates effects of actual cavities inside the head. The homogeneous sphere model is used for assessing the effects caused by neglecting the cavity in the volume conductor model in the inverse dipole fitting procedure. Four electrode configurations have been examined to investigate their relation to the EEG inverse dipole solution. After examination of 2520 dipoles in the brain, the effects of cavities in the human head are found to be negligible when the dipole is located in the cortex or in the subcortex. When the dipole is located in the brain stem, the EEG inverse dipole solution is strongly affected by the cavity and is sensitive to the electrode configuration on the scalp. The EEG inverse dipole solution in the deep brain is sensitive to inhomogeneity in the lower part of the head when a single positive or negative potential pole is observed by the electrodes on the scalp, and at the same time is sensitive to the extent of the scalp covered by the electrodes. In conclusion, the electrodes should cover as much of the upper scalp as possible for deep source localization.

Algorithms↗
PubMed1989

[Estrogen and progesterone receptors in human ovary and ovarian tumors].

Ovarian specimens from 159 different patients were analyzed for estrogen and progesterone receptor (ER and PR) content with the Dextran-coated Charcoal method. The results indicated that the contents of ER and PR in malignant ovarian tumors were not correlated with the menstrual cycle of the patient, clinical stage and differentiation of the tumor. Among malignant ovarian tumors, the mean ER and PR concentrations in sex-cord stromal tumors and endometrioid carcinomas were higher than those in other malignant ovarian tumors (P less than 0.05, P less than 0.025). This suggests the possibility of endocrine therapy for these patients with the hope for a better prognosis.

Adenocarcinoma↗
PubMed1988

Dipole-tracing of 'awareness' attenuating the cortical components of somatosensory evoked potentials.

Using the dipole-tracing method, the source generators of N18, P22 and P40 of the somatosensory evoked potential (SEP) were estimated as the equivalent dipole. After voluntary action of the thumb flexion, no changes were observed in N18 or P40, but the amplitude of P22 was suppressed. The after-effects of intention accompanied by a voluntary action or the subject's awareness that electrical stimulation will be given after the voluntary action were treated as 'awareness'. By subtracting the pure SEP from SEP during 'awareness', it was found that the equivalent dipole of 'awareness' of P22 was located at the same region of pure P22, but the vector was of opposite orientation. 'Awareness' attenuated the perceptive potential of SEP like P22 generated in the cortex.

Awareness↗
PubMed1987

Dipole-tracing method applied to human brain potentials.

A new computer-aided method was developed to estimate the location of an electric source generator (e.g. a current dipole) in the human brain. Brain activity such as somatosensory evoked potentials was recorded with 21 surface electrodes over the scalp. To solve the inverse problem, it was assumed that only one dipole is elicited at a given time, and that the head is embedded in an infinite and homogeneous conductor. The exact geometry of the human head was measured from 17 slices of CT-images of a real head to arrange a human head model. A dipole with a given moment and location is assumed in the head model. Potential distribution elicited by the dipole is compared with potential distribution which was the actual recorded one. The optimal dipole location was calculated, using the simplex method. Hence, the optimal dipole moment was obtained. The accuracy of estimation as an equivalent dipole was expressed in terms of dipolarity.

Brain↗