Biomedical subjects

P Wan

Publications and source records attributed to P Wan.

4 recordsLinked to original sources

PubMed1995

[Hypocrellin B-ethanolamine (HB-E) sensitized photodamage on rat mitochondria].

The Hypocrellin B-Ethanolamine (HB-E) sensitized photodamage on lipid peroxidation, sulfhydryl oxidation and ATPase inactivation of rat liver mitochondria was studied under illumination of 640 nm, The HB-E sensitized photodamage of lipid peroxidation is less than sulfhydryl photooxidation, when HB-E concentration is 50 mumol/L. To elucidate the mechanism of photodamage of HB-E, antioxidant: BHT, Vit E, oxygen radical quencher: L-His, beta-Cart, were investigated. The results showed that HB photodamage of mitochondria is not only by oxygen radical, but also by HB-E radical as well. From compared tests among HB, HA, Hp, MB and HB-E, we found that HB-E had higher ability to photodamage lipid peroxidation, sulfhydryl oxidation and tryptophan than other photosensitizers. The experiments showed that the superoxide generated may be by HB-E radical.

Adenosine Triphosphatases↗

PubMed1994

[Case report of pulmonary histoplasmosis].

A case of pulmonary histoplasmosis in Beijing was reported Patient's CT scan showed naly patchy consolidation partly with small cavitations and hilar silhouette enlarged in both lungs. On pathologic examination, Histoplasma Capsutatums were found in the lung tissures by percutaneous lung biopsy. Skin rash had developed in the course. After treated by fluconaxole, most of the lung lesions and skin rash disappeared.

Adult↗

PubMed1990

[Cytological study on Eclipta prostrata L].

The authors report that the karyotype formula of Eclipta prostrata is K(2n) = 22 = 16m + 6sm, which belongs to "1A" of stebbins, the chromosome composition based on relative length is 2n = 22 = 10M2 + 12M1, and the total length of the chromosome is 29.3 microns. The chromosome volume of E. prostrata has also been calculated.

Chromosomes↗

PubMed1987

Cytotoxicity of compounds that interfere with the regulation of intracellular pH: a potential new class of anticancer drugs.

The extracellular pH (pHe) in many solid tumors is often lower than in normal tissues. Cells may survive conditions of acid pHe because antiports in their membrane exchange Na+ for H+, or HCO3- for Cl-, and thus regulate the intracellular pH (pHi). We have therefore assessed the effects of drugs which interfere with regulation of pHi on survival of Chinese hamster ovary and human bladder cancer MGH-U1 cells in tissue culture. Nigericin, an ionophore which acidifies the cytoplasm when cells are placed in medium at low pHe, was not toxic at pHe 6.5 or above but became very toxic as pHe was reduced below this value. Amiloride and 4,4'-diisothiocyanostilbene 2,2-disulfonic acid, inhibitors of the Na+/H+ and HCO3-/Cl- exchangers, respectively, decreased pHi in the presence of nigericin at low pHe. These drugs showed little or no toxicity in the pHe range of 6.0-7.0 but added greatly to the toxicity of nigericin. A combination of all three drugs led to toxicity in the pHe range of 6.5-6.8, well within the measured range of tumor pH, but not at pHe 7.0 or above. A combination of low pH and hypoxia, two conditions likely to be found in regions distant from tumor blood vessels, caused cell mortality in the absence of drugs, and this effect was increased by nigericin used alone or in combination with amiloride and 4,4'-diisothiocyanostilbene 2,2-disulfonic acid. These drugs may be regarded as prototypes for potential new anticancer agents that might achieve selective killing of tumor cells by interfering with the regulation of intracellular pH.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗