Biomedical subjects
Publications and source records attributed to P Tuchinda.
Two new 2-substituted furans, 1-(2-furyl)pentacosa-16,18-diyne and 23-(2-furyl)tricosa-5,7-diynoic acid, have been isolated from stems of Polyalthia suberosa. The structures were assigned by spectroscopic methods. The two compounds together with the previously reported kalasinamide, N-trans-feruloyltyramine and N-trans-coumaroyltyramine showed anti-HIV activities.
The General Practice was approved by the Thai Medical Council as a specialty in 1969. The residency training programs were revised in 1992. The first three - year rotating postgraduate residency training program was started in 1973 with a total of 9 programs by the late 1980s. Seven were in Bangkok, and the other 2 were in the North. The programs contained curricula objectives, clinical rotation in various disciplines including a general practice block in provincial or community hospitals. The weakness of the programs was the lack of a general practice department, a general practice trainer or preceptor and a general practice course organizer. Finally, the General Practitioners Association played a little role in the postgraduate general practice residency. After the revision, the general practice residency was changed to family medicine residency training in 1999. The College of Family Physicians of Thailand was established to take a central role in postgraduate education.
An azaanthracene alkaloid, 1-aza-9,10-dimethoxy-4-methyl-2-oxo-1,2-dihydroanthracene (kalasinamide) has been isolated from the stems of Polyalthia suberosa. In addition, the known N-trans-feruloyltyramine and N-trans-coumaroyltyramine are also reported from the same source. The structures were elucidated by spectroscopic methods.
Triptolide, a highly oxygenated diterpene isolated from Tripterygium wilfordii Hook f. (Celastraceae), has been shown to demonstrate potent antileukemic activity in rodent models at remarkably low treatment doses. A variety of other physiological responses are known to be mediated by this compound, including immunosuppressive and antifertility effects. We currently report that triptolide was not mutagenic toward Salmonella typhimurium strain TM677, either in the presence or absence of a metabolic activating system. Relatively potent but non-specific cytotoxicity was observed with a panel of cultured mammalian cell lines, and modest antitumor activity was observed when an i.p. dose of 25 microg was administered three times weekly to athymic mice carrying human breast tumors. Treatment regimens involving higher doses of triptolide (e.g. 50 microg/mouse three times weekly) were lethal.
Bioassay-guided fractionation of a hexane extract of the rhizomes of Curcuma xanthorrhiza Roxb. (Zingiberaceae) led to the isolation of three non-phenolic diarylheptanoids, identified mainly by high-field 1H-NMR as trans-trans-1,7-diphenyl-1,3-heptadien-4-one (alnustone), trans-1,7-diphenyl-1-hepten-5-ol, and trans,trans-1,7-diphenyl-1,3-heptadien-5-ol. The latter is reported for the first time as a plant constituent. Germacrone, curzerenone, and cinnamaldehyde were also isolated and identified. The three diarylheptanoids all exerted significant anti-inflammatory activity in the assay of carrageenin-induced hind paw edema in rats.
A new ring-A secotriterpene, koetjapic acid [1], and five known compounds, 3-oxo-olean-12-en-29-oic acid [2] (a novel natural product), katonic acid [3], (-)-alloaromadendrene, (-)-caryophyllene oxide, and (+)-spathulenol, have been isolated and characterized from a cytotoxic Et2O-soluble extract of Sandoricum koetjape stems. Of these compounds, 2 and 3 demonstrated significant cytotoxic activity against cultured P-388 cells (ED50 values of 0.61 and 0.11 microgram/ml, respectively). Significant, albeit less intense, cytotoxicity was also observed with a variety of cultured human cancer cells. The 13C-nmr chemical shifts of these triterpenes were assigned unambiguously using selective INEPT nmr experiments. Aside from compounds 2 and 3, these substances were not toxic with cultured cells.
Five known cardenolides, digitoxigenin (1), oleandrigenin (2), digitoxigenin alpha-L-cymaroside (3), digitoxigenin beta-gentiobiosyl-alpha-L-cymaroside (4), and delta 16-digitoxigenin beta-D-glucosyl-alpha-L-cymaroside (5), were isolated from the stems of Beaumontia brevituba Oliver by cytotoxicity-directed fractionation monitored by a cultured human lung cancer cell line. The cytotoxic activity of these compounds was evaluated with a panel of twelve human and murine cancer cell lines. The lignan glycoside, syringaresinol beta-D-glucoside, was obtained for the first time in the form of its levo-enantiomer.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Twenty-four hour urinary histamine in 12 patients with DHF compared to 12 normal subjects in the comparable age and sex were studied. The results revealed significantly increased urinary excretion in patients with DHF than in normal subjects in both free and total forms. This finding suggests that histamine may be one, if not all, of the mediators released during the course of the disease, especially in the severe cases. Histamine may play an important role for the leakage of intravascular fluid to the various serous spaces resulting in hypovolemia and shock.
Explore the source record for details and available documents.
During the period August 1970 through July 1973, about 50 faecal specimens collected each month from healthy pre-school children of lower economic status in Bangkok were studied for virus isolation using primary monkey kidney cells and new born mice. From a total of 1,823 samples, 557 (30.5%) were positive: 86 (4.8%) polioviruses, 77 (4.2%) coxsackieviruses B, 223 (12.2%) echoviruses, and 127 strains (7.0%) of unidentified viruses. Altogether, 45 serotypes of enteric viruses were identified. More than 30 serotypes, including the 3 types of poliovirus, were present each year. Infection rates were higher in males than in females and highest at one year of age, the rates decreasing with progressing age. There was no marked seasonal variation of enterovirus infections in Bangkok. The poliovirus infection index was low from September to January, and the index of polio and non-polio enterovirus infections was highest in April.
Explore the source record for details and available documents.
Explore the source record for details and available documents.