751
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Abstract
Expression of the early regions of several primate polyomaviruses (SV40, BKV, JCV, and LPV) in hamster cells induces transformation, manifested by the ability to grow in soft agar. Hamster cells transformed by SV40 contain complexes between the SV40 T antigen and the cellular tumor suppressor protein p53. We detected analogous complexes between p53 and the BKV T antigen in hamster cells transformed by the BKV early region, where the half life of p53 increased 16-fold. However, neither a LPV-transformed hamster fibroblast cell line [LPV-HE (F); K. K. Takemoto and T. Kanda, 1984, J. Virol. 50, 100-105] nor BHK-21 cells transformed by the LPV early region contained detectable complexes between the LPV T antigen and p53, nor was the stability of p53 in LPV transformed BHK-21 cells altered. Association between hamster p53 and the LPV T antigen expressed as glutathione S-transferase fusion protein could not be detected in vitro. These data indicate that alteration of the amount or stability of p53 is not required for transformation of hamster cells by LPV. However, as viruses such as SV40 and BKV whose T antigens bind p53 are oncogenic in hamsters, whereas LPV is not, the alteration of p53 amount or stability may be required for tumorigenesis.
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Affiliation(s)
- S Kang
- Department of Biochemistry, University of Missouri, Columbia 65212
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752
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Miller AH, Spencer RL, Pulera M, Kang S, McEwen BS, Stein M. Adrenal steroid receptor activation in rat brain and pituitary following dexamethasone: implications for the dexamethasone suppression test. Biol Psychiatry 1992; 32:850-69. [PMID: 1334712 DOI: 10.1016/0006-3223(92)90175-y] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The dexamethasone suppression test (DST) has been used extensively to evaluate feedback inhibition of the hypothalamic-pituitary-adrenal (HPA) axis by adrenal steroids. Nevertheless, it remains unclear at what level of the HPA axis and through which adrenal steroid receptor subtype dexamethasone exerts its inhibitory effect. Because adrenal steroid receptor activation is an important prerequisite for dexamethasone to affect cellular function, HPA axis tissues that exhibit evidence of receptor activation following dexamethasone administration are likely site(s) of action for this synthetic hormone to inhibit HPA axis activity. Therefore, type-I and type-II adrenal steroid receptor activation was assessed in the pituitary, hypothalamus, and hippocampus of intact and adrenalectomized rats after overnight exposure to various oral doses of dexamethasone. Results with dexamethasone were compared to similar studies using corticosterone, the endogenous glucocorticoid of the rat. All dexamethasone doses led to significant type-II receptor activation in the pituitary, whereas only an exceedingly high dexamethasone dose activated type-II receptors in the hippocampus and hypothalamus. Dexamethasone had little effect on type I receptors in any tissue at any dose. In contrast, corticosterone significantly activated type-I receptors in all tissues, whereas it activated type-II receptors in the brain and not the pituitary at physiological concentrations. Because dexamethasone activated pituitary type-II receptors at blood concentrations that did not activate type-II receptors in the brain, these results suggest that the DST in humans may primarily be a measure of type-II adrenal steroid receptor feedback inhibition at the level of the pituitary.
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Affiliation(s)
- A H Miller
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY 10029
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753
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Kang S, Wells RD. Central non-Pur.Pyr sequences in oligo(dG.dC) tracts and metal ions influence the formation of intramolecular DNA triplex isomers. J Biol Chem 1992; 267:20887-91. [PMID: 1400403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The effect of the central non-Pur.Pyr sequences in oligo(dG.dC) inserts on determining the type of intramolecular DNA triplex isomers formed in negatively supercoiled plasmids was investigated. Different triplex types (H-r3, H-r5, and H-y3), revealed by a combination of chemical probing and Maxam-Gilbert sequencing reactions, were adopted by the oligo(dG.dC) tracts depending on the length and composition of the central non-Pur.Pyr sequences (0, 3, or 5 base pairs) and the kind of metal ions. The H-r3 triplex conformer, one isomer of a Pur.Pur.Pyr structure, was formed in the (C)20 and (C)10GCG(C)10 inserts in plasmids in the presence of certain metal ions. Interestingly, H-r5, the other isomer of the Pur.Pur-Pyr triplex which had not been detected previously, was formed in a (C)9GAATT(C)9 insert in the presence of either Mg2+ or Ca2+. Alternatively, H-y3, one isomer of a Pyr.Pur.Pyr triplex, was formed in the (C)9GAATT(C)9 insert in the absence of metal ions. Thus, central non-Pur.Pyr sequences and metal ions play a role as determinants of the types of intramolecular triplexes formed; they also reduce the requirement of longer Pur.Pyr repeat sequences to form intramolecular triplexes. Furthermore, the effects of MgCl2 concentration and pH on the formation of triplex isomers were examined. The Pur.Pur.Pyr conformations (H-r3 and H-r5) may be the favored conformations in the cellular milieu, since they are stable at physiological pH and metal ion concentration.
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Affiliation(s)
- S Kang
- Institute of Biosciences and Technology, Texas A & M University, Texas Medical Center, Houston 77030
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754
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Abstract
BACKGROUND Development of multiple primary cutaneous melanomas is a well-recognized phenomenon. As with single primary melanoma, personal and family histories of melanoma and dysplastic nevi (DN) are considered important risk factors. The natural history and impact of regular follow-up evaluation of this entity were examined. METHOD Through a search of the computerized data bank of the Pathology Department and the Melanoma Registry of the Pigmented Lesion Clinic at Massachusetts General Hospital, 41 patients with multiple cutaneous melanomas were identified. RESULTS Mean (+/- standard error) age at first diagnosis was 49 +/- 2 years (range, 21-75 years). The male to female ratio was 2:1. The median number of primary melanomas was two (88%). Three patients had three and one had five. Melanoma types included superficial spreading (70%), nodular (8%), lentigo maligna (2%), and unclassified (10%), and in 7% the type was unknown. Nineteen (46%) patients had histologic and/or clinical evidence of DN. For the group with DN, the mean age at first diagnosis (44 +/- 3 years) was significantly less than that of patients without DN (54 +/- 3 years) (P less than 0.05). Family history of melanoma was found in 10 patients (24%). Multiple melanomas were diagnosed concurrently in 16 patients (39%), whereas in 25 (61%) diagnosis was sequential. For the latter group, the mean tumor thickness from the first (1.21 +/- 0.28 mm) to the second melanoma (0.51 +/- 0.08 mm) decreased significantly (P less than 0.05); the median time interval was 36 months (range, 2-372 months). CONCLUSION These data confirm the need for complete skin examination for patients with newly diagnosed melanoma; and, with subsequent melanomas appearing as long as 31 years after the first melanoma, continued follow-up with complete skin examinations seems prudent.
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Affiliation(s)
- S Kang
- Department of Dermatology, Massachusetts General Hospital, Harvard Medical School, Boston
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755
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Kang S, Wohlrab F, Wells RD. GC-rich flanking tracts decrease the kinetics of intramolecular DNA triplex formation. J Biol Chem 1992; 267:19435-42. [PMID: 1527063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The effect of the base composition of flanking sequences on DNA intramolecular triplex formation was investigated in negatively supercoiled plasmids. The rates of triplex formation at two oligopurine.oligopyrimidine inserts with interrupting sequences in plasmids containing AT- or GC-rich flanking sequences were compared as a function of temperature, pH, and negative superhelical density. The kinetics of the transition of linear B-DNA to triplex (also called H-DNA) were influenced by all of these factors; triplexes were formed slower in a GC-rich background than in an AT-rich background. However, at equilibrium, the same amounts of the triplexes in AT- or GC-rich contexts were formed, and the conformations adopted by (GAA)4TTCGC(GAA)4 showed the canonical intramolecular triplex as mapped with chemical probes. We propose that the GC-rich segments caused this effect by thermodynamically clamping the DNA inserts, since the dependence of kinetics on base composition disappeared in tetraalkylammonium ions which eliminate the dependence of helix-coil transitions on base composition. The dependence of the kinetics of intramolecular triplex formation on flanking sequences further strengthens the concept of the role of DNA as a dynamic participant in cellular events.
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Affiliation(s)
- S Kang
- Institute of Biosciences and Technology, Texas A & M University, Houston 77030
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756
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757
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Kang S, Chen S. [Isolation and identification of julibrotriterpennoidal lactone A from Albizia julibrissin Durazz]. Zhongguo Zhong Yao Za Zhi 1992; 17:357-8, 384. [PMID: 1418582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Julibrotriterpennoidal lactone A was isolated from the cortex of Albizia julibrissin. Its structure (the C28----C21 lactone of, 3 beta, 16 beta, 21 beta-trihydroxy-delta 12-oleanen-28-oic acid) has been determined on the basis of spectral evidence (IR, 1HNMR, 13C NMR and MS).
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Affiliation(s)
- S Kang
- Laboratory of Chinese Materia Medica, Chengde Medical College
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758
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Kang S, Barnhill RL, Graeme-Cook F, Randolph G, Nadol JB, Sober AJ. Primary malignant melanoma of the external auditory canal: a case report with presentation as an aural polyp. Am J Otol 1992; 13:194-6. [PMID: 1599012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A case of primary cutaneous melanoma of the external auditory canal and a review of the literature are reported. This is the first reported case with microstaging of the tumor. The tumor presented as a polypoid obstructive lesion of the external ear canal. Although occurrence of melanoma in this location is extremely rare, differential diagnosis of an external ear canal polyp should be expanded to include primary malignant melanoma.
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Affiliation(s)
- S Kang
- Department of Dermatology, Massachusetts General Hospital, Boston 02114
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759
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Kang S, Zhang J, Lu Y, Lu D. [Chemical constituents of Rhodiola kirilowii (Reg.) Reg]. Zhongguo Zhong Yao Za Zhi 1992; 17:100-1, 127. [PMID: 1384543] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Three compounds were isolated from the water-soluble part of alcohol extracts of rhizomes of Rhodiola kirilowii. Two of them were identified as salidroside and tyrosol, respectively by chemical and spectral analysis. beta-sitosterol was obtained from the petroleum extracts of the plant.
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Affiliation(s)
- S Kang
- Institute of Qinghai High Altitude Medical Scientific Research, Xining
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760
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Affiliation(s)
- A J Sober
- Department of Dermatology, Harvard Medical School, Boston, Massachusetts
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761
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Kang S, Brange J, Burch A, Vølund A, Owens DR. Subcutaneous insulin absorption explained by insulin's physicochemical properties. Evidence from absorption studies of soluble human insulin and insulin analogues in humans. Diabetes Care 1991; 14:942-8. [PMID: 1797506 DOI: 10.2337/diacare.14.11.942] [Citation(s) in RCA: 97] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To study the influence of molecular aggregation on rates of subcutaneous insulin absorption and to attempt to elucidate the mechanism of absorption of conventional soluble human insulin in humans. RESEARCH DESIGN AND METHODS Seven healthy male volunteers aged 22-43 yr and not receiving any drugs comprised the study. This study consisted of a single-blind randomized comparison of equimolar dosages of 125I-labeled forms of soluble hexameric 2 Zn2+ human insulin and human insulin analogues with differing association states at pharmaceutical concentrations (AspB10, dimeric; AspB28, mixture of monomers and dimers; AspB9, GluB27, monomeric). After an overnight fast and a basal period of 1 h, 0.6 nmol/kg of either 125I-labeled human soluble insulin (Actrapid HM U-100) or 125I-labeled analogue was injected subcutaneously on 4 separate days 1 wk apart. Absorption was assessed by measurement of residual radioactivity at the injection site by external gamma-counting. RESULTS The mean +/- SE initial fractional disappearance rates for the four preparations were 20.7 +/- 1.9 (hexameric soluble human insulin), 44.4 +/- 2.5 (dimeric analogue AspB10), 50.6 +/- 3.9 (analogue AspB28), and 67.4 +/- 7.4%/h (monomeric analogue AspB9, GluB27). Absorption of the dimeric analogue was significantly faster than that of hexameric human insulin (P less than 0.001); absorption of monomeric insulin analogue AspB9, GluB27 was significantly faster than that of dimeric analogue AspB10 (P less than 0.01). There was an inverse linear correlation between association state and the initial fractional disappearance rates (r = -0.98, P less than 0.02). Analysis of the disappearance data on a log linear scale showed that only the monomeric analogue had a monoexponential course throughout. Two phases in the rates of absorption were identified for the dimer and three for hexameric human insulin. The fractional disappearance rates (%/h) calculated by log linear regression analysis were monomer 73.3 +/- 6.8; dimer 44.4 +/- 2.5 from 0 to 2 h and 68.9 +/- 3.5 from 2.5 h onward; and hexameric insulin 20.7 +/- 1.9 from 0 to 2 h, 45.6 +/- 5.0 from 2.5 to 5 h, and 70.6 +/- 6.3 from 5 h onward. CONCLUSIONS Association state is a major determinant of rates of absorption of insulin and insulin analogues. The lag phase and the subsequent increasing rate of subcutaneous soluble insulin absorption can be explained by the associated state of native insulin in pharmaceutical formulation and its progressive dissociation into smaller units during the absorption process.
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Affiliation(s)
- S Kang
- Department of Medicine, University of Wales College of Medicine, Cardiff, United Kingdom, Research Institute
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762
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Kang S, Brange J, Burch A, Vølund A, Owens DR. Absorption kinetics and action profiles of subcutaneously administered insulin analogues (AspB9GluB27, AspB10, AspB28) in healthy subjects. Diabetes Care 1991; 14:1057-65. [PMID: 1797487 DOI: 10.2337/diacare.14.11.1057] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The subcutaneous absorption and resulting changes in plasma insulin or analogue, glucose, C-peptide, and blood intermediary metabolite concentrations after subcutaneous bolus injection of three soluble human insulin analogues (AspB9GluB27, monomeric; AspB28, mixture of monomers and dimers; and AspB10, dimeric) and soluble human insulin were evaluated. RESEARCH DESIGN AND METHODS Fasting healthy male volunteers (n = 7) were studied on five occasions 1 wk apart randomly receiving 0.6 nmol.kg-1 s.c. 125I-labeled AspB10 or soluble human insulin (Novolin R, Novo, Copenhagen); 1st study and 0.6 nmol.kg-1 s.c. 125I-labeled AspB28, AspB9GluB27 or soluble human insulin (2nd study). Residual radioactivity at the injection site was measured over 8 h with frequent venous sampling for plasma immunoreactive insulin or analogue, glucose, C-peptide, and blood intermediary metabolite concentrations. RESULTS The three analogues were absorbed 2-3 times faster than human insulin. The mean +/- SE time to 50% residual radioactivity was 94 +/- 6 min for AspB10 compared with 184 +/- 10 min for human insulin (P less than 0.001), 83 +/- 8 min for AspB28 (P less than 0.005), and 63 +/- 9 min for AspB9GluB27 (P less than 0.001) compared with 182 +/- 21 min for human insulin. delta Peak plasma insulin analogue levels were significantly higher after each analogue than after human insulin (P less than 0.005). With all three analogues, the mean hypoglycemic nadir occurred earlier at 61-65 min postinjection compared with 201-210 min for the reference human insulins (P less than 0.005). The magnitude of the hypoglycemic nadir was greater after AspB9GluB27 (P less than 0.05) and AspB28 (P less than 0.001) compared with human insulin. There was a significantly faster onset and offset of responses in C-peptide and intermediary metabolite levels after the analogues than after human insulin (P less than 0.05). CONCLUSIONS The rapid absorption and biological actions of these analogues offer potential therapeutic advantages over the current short-acting neutral soluble insulins.
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Affiliation(s)
- S Kang
- Department of Medicine, University of Wales College of Medicine, Cardiff, United Kingdom
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763
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Kang S, Zou Z, Qiao X. [The qualitative and quantitative analyses of protein with a novel fluorescence agent (EPQS) by fluorescent scanning on solid substrate]. Hua Xi Yi Ke Da Xue Xue Bao 1991; 22:262-5. [PMID: 1748409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We synthesized a new fluorescence agent, EPQS, which could be soluble in water and was stable in the analytical process. It was characteristic of good fluorescence parameters. Human serum albumin (HSA) was marked with EPQS and purified by the paper electrophoresis dialysis. We determined the fluorescent spectra and excitation spectra of the marked HSA, or EPQS on the cellulose acetate paper by RF-510 fluorescence spectrophotometer-thin-layer chromatoscanner. The former lambda ex = 370nm lambda em = 470nm; the latter lambda ex = 382nm lambda em = 476 nm. Then we touched different quantity of EPQS-HSA upon the cellulose acetate. The fluorescent scanning on the paper disclosed that the relationship between the quantity adopted and the fluorescence intensity is linear. These showed that the protein could be quickly determined qualitatively and quantitatively by this simple method, and EPQS was useful.
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764
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Kang S, Creagh FM, Peters JR, Brange J, Vølund A, Owens DR. Comparison of subcutaneous soluble human insulin and insulin analogues (AspB9, GluB27; AspB10; AspB28) on meal-related plasma glucose excursions in type I diabetic subjects. Diabetes Care 1991; 14:571-7. [PMID: 1914797 DOI: 10.2337/diacare.14.7.571] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE To compare postprandial glucose excursions and plasma free insulin-analogue levels after subcutaneous injection of three novel human insulin analogues (AspB10; AspB9, GluB27; and AspB28) with those after injection of soluble human insulin (Actrapid HM U-100). RESEARCH DESIGN AND METHODS Six male subjects with insulin-dependent diabetes, at least 1 wk apart and after an overnight fast and basal insulin infusion, received 72 nmol (approximately 12 U) s.c. of soluble human insulin 30 min before, or 72 nmol of each of the three analogues immediately before, a standard 500-kcal meal. RESULTS Mean basal glucoses were similar on the 4 study days. Compared to human insulin (6.3 +/- 0.8 mM), mean +/- SE peak incremental glucose rises were similar after analogues AspB10 (5.4 +/- 0.8 mM) and AspB9, GluB27 (5.4 +/- 0.7 mM) and significantly lower after analogue AspB28 (3.6 +/- 1.2 mM, P less than 0.02). Relative to soluble human insulin (100% +/- SE21), incremental areas under the glucose curve between 0 and 240 min were 79% +/- 34 (AspB10, NS), 70% +/- 29 (AspB9, GluB27, NS), and 43% +/- 23 (AspB28, P less than 0.02). Basal plasma free insulin levels were similar on the 4 study days. Plasma free insulin-analogue levels rose rapidly to peak 30 min after injection at 308 +/- 44 pM (AspB10); 1231 +/- 190 pM (AspB9, GluB27) and 414 +/- 42 pM (AspB28) and were significantly higher than corresponding (i.e., 30 min postmeal) plasma free insulin levels of 157 +/- 15 pM (P less than 0.02 in each case). CONCLUSIONS Plasma profiles of the insulin analogues were more physiological than that of human insulin after subcutaneous injection. All three analogues given immediately before the meal are at least as effective as soluble human insulin given 30 min earlier. These analogues are promising potential candidates for short-acting insulins of the future.
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Affiliation(s)
- S Kang
- Department of Medicine, University of Wales College of Medicine, Cardiff, United Kingdom
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765
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Markowitz JS, Cosimi LA, Carey RW, Kang S, Padyk C, Sober AJ, Cosimi AB. Prognosis after initial recurrence of cutaneous melanoma. Arch Surg 1991; 126:703-7; discussion 707-8. [PMID: 2039357 DOI: 10.1001/archsurg.1991.01410300045006] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We reviewed 231 patients who developed recurrent disease 1 to 218 months after surgical therapy for clinical stage I cutaneous melanoma. Metastatic lesions amenable to surgery, including visceral recurrences, were resected. Adjuvant systemic chemotherapy/immunotherapy or regional hyperthermic perfusion was added in patients with unresected disease. Local irradiation was employed for nonresectable brain or other isolated symptomatic metastases. The overall 5-year survival rate after initial recurrence was 36%. In patients with soft tissue or nodal recurrence, the 5-year survival rates were 49% and 38%, respectively; six (11%) of 53 patients whose initial recurrence was in a visceral organ achieved prolonged remission. Primary lesion anatomic site, thickness, pathologic type, and interval from initial therapy to recurrence were unrelated to survival. Significant prognostic factors included the site of initial metastasis, stage of primary disease, and the successful complete eradication of gross disease by surgical excision or intensive chemotherapy.
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Affiliation(s)
- J S Markowitz
- General Surgical, Massachusetts General Hospital, Boston 02114
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766
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Yuan A, Kang S, Qin L, Ruan B, Fan Y. [Isolation and identification of aloesin from the leaves of Aloe vera L. var, chinensis (Haw.) Berger]. Zhongguo Zhong Yao Za Zhi 1991; 16:292-3, 319. [PMID: 1781897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- A Yuan
- Guangxi Institute of Traditional Chinese Medical and Pharmaceutical Sciences, Nanning
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767
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Kang S, Sproull RD. Iron oxidation by Thiobacillus ferrooxidans. Scientific note. Appl Biochem Biotechnol 1991; 28-29:907-15. [PMID: 1929392 DOI: 10.1007/bf02922660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- S Kang
- Department of Chemical Engineering, Oregon State University, Corvallis 97331-2702
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768
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Abstract
In response to phosphorus starvation, Neurospora crassa makes several enzymes that are undetectable or barely detectable in phosphate-sufficient cultures. The nuc-1+ gene, whose product regulates the synthesis of these enzymes, was cloned and sequenced. The nuc-1+ gene encodes a protein of 824 amino acids with a predicted molecular weight of 87,429. The amino acid sequence shows homology with two yeast proteins whose functions are analogous to that of the NUC-1 protein. Two nuc-1+ transcripts of 3.2 and 3.0 kilobases were detected; they were present in similar amounts during growth at low or high phosphate concentrations. The nuc-2+ gene encodes a product normally required for NUC-1 function, and yet a nuc-2 mutation can be complemented by overexpression of the nuc-1+ gene. This implies physical interactions between NUC-1 protein and the negative regulatory factor(s) PREG and/or PGOV. Analysis of nuc-2 and nuc-1; nuc-2 strains transformed by the nuc-1+ gene suggests that phosphate directly affects the level or activity of the negative regulatory factor(s) controlling phosphorus acquisition.
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Affiliation(s)
- S Kang
- Department of Physiological Chemistry, University of Wisconsin, Madison 53706
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769
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Abstract
Due to the inherent pharmacokinetic properties of available insulins, normoglycemia is rarely, if ever, achieved in insulin-dependent diabetic patients without compromising their quality of life. Subcutaneous insulin absorption is influenced by many factors, among which the associated state of insulin (hexameric) in pharmaceutical formulation may be of importance. This review describes the development of a series of human insulin analogues with reduced tendency to self-association that, because of more rapid absorption, are better suited to meal-related therapy. DNA technology has made it possible to prepare insulins that remain dimeric or even monomeric at high concentration by introducing one or a few amino acid substitutions into human insulin. These analogues were characterized and used for elucidating the mechanisms involved in subcutaneous absorption and were investigated in preliminary clinical studies. Their relative receptor binding and in vitro potency (free-fat cell assay), ranging from 0.05 to 600% relative to human insulin, were strongly correlated (r = 0.97). In vivo, most of the analogues exhibited approximately 100% activity, explainable by a dominating receptor-mediated clearance. This was confirmed by clamp studies in which correlation between receptor binding and clearance was observed. Thus, an analogue with reduced binding and clearance gives higher circulating concentrations, counterbalancing the reduced potency at the cellular level. Absorption studies in pigs revealed a strong inverse correlation (r = 0.96) between the rate of subcutaneous absorption and the mean association state of the insulin analogues. These studies also demonstrated that monomeric insulins were absorbed three times faster than human insulin. In healthy subjects, rates of disappearance from subcutis were two to three times faster for dimeric and monomeric analogues than for human insulin. Concomitantly, a more rapid rise in plasma insulin concentration and an earlier hypoglycemic response with the analogues were observed. The monomeric insulin had no lag phase and followed a monoexponential course throughout the absorption process. In contrast, two phases in rate of absorption were identified for the dimer and three for the normal hexameric human insulin. The initial lag phase and the subsequent accelerated absorption of soluble insulin can now be explained by the associated state of native insulin in pharmaceutical formulation and its progressive dissociation into smaller units during the absorption process. In the light of these results, the effects of insulin concentration, injected volume, temperature, and massage on the absorption process are now also understood.(ABSTRACT TRUNCATED AT 400 WORDS)
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Affiliation(s)
- J Brange
- Novo Research Institute, Novo Nordisk A/S, Bagsvaerd, Denmark
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770
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Affiliation(s)
- S Kang
- Department of Dermatology, Harvard Medical School, Massachusetts General Hospital, Boston 02114
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771
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Chung WS, Kang S, Lee J, Kim J. Extended N=2 superconformal algebra. Phys Rev D Part Fields 1990; 41:1205-1208. [PMID: 10012453 DOI: 10.1103/physrevd.41.1205] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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772
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Abstract
Postprandial plasma glucose excursions and plasma levels of free insulin after subcutaneous bolus injection of a rapidly absorbed monomeric insulin analogue (B9AspB27Glu) or soluble human insulin ('Actrapid HM' U100) were studied in six insulin-treated diabetic subjects. 10 U actrapid or an equimolar amount of the analogue were injected, in random order with an interval of 1 week, immediately before a 500 kcal test meal. Basal insulin levels were similar on the 2 study days (mean 74.1 [SE 5.1] pmol/l, actrapid; 79.7 [13.0] pmol/l, analogue). After injection of actrapid plasma free insulin levels rose slowly, reaching a plateau by 105 min at 222 (19) pmol/l. Injection of the analogue resulted in a rapid early peak at 30 min (798 [112] pmol/l), and levels were significantly higher than those after actrapid between 15 and 210 min. The more physiological plasma insulin levels achieved with the analogue were accompanied by a substantial reduction in postprandial plasma glucose excursions; the integrated area under the incremental plasma glucose curve was 45% lower after the analogue than after actrapid.
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Affiliation(s)
- S Kang
- Diabetes Research Unit, University of Wales College of Medicine, Cardiff, UK
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773
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Niemetz J, Kang S. A streptokinase dependent plasma factor (SKDF) induces leucocyte tissue factor activity. Br J Haematol 1988; 70:427-33. [PMID: 2975501 DOI: 10.1111/j.1365-2141.1988.tb02512.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Various inducers endow human leucocytes with a procoagulant activity of tissue factor type. We have observed a novel plasma factor which in combination with streptokinase induces powerful leucocyte procoagulant activity. This streptokinase dependent factor (SKDF) is present in normal plasma or serum albeit quantitatively different in individual donors. The generation of tissue factor activity as a function of streptokinase-plasma complex shows a specific and saturable sigmoidal dose-response curve. The Hill plot shows a straight line with Hill coefficient, H = 2.2, suggesting a strong positive cooperativity for the binding of this streptokinase-plasma complex to the leucocyte surface receptor for the signal transduction leading to the biosynthesis of tissue factor apoprotein. It also suggests that the leucocyte surface receptor for streptokinase-plasma complex differs from that for endotoxin lipopolysaccharides. SKDF is of apparent high molecular weight. It does not appear to be an antibody to streptokinase since its level does not correlate with the level of antibodies to streptokinase, and it does not correlate with the antistreptolysin titre. Furthermore, SKDF does not bind to protein A. It has a narrow pH range of stability, and is destroyed at 56 degrees C, or at freeze-drying, Urokinase, another plasminogen activator, or plasmin were unable to activate SKDF to induce the leucocyte procoagulant activity. SKDF may play a role in thrombolytic therapy.
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774
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Vora JP, Owens DR, Dolben J, Atiea JA, Dean JD, Kang S, Burch A, Brange J. Recombinant DNA derived monomeric insulin analogue: comparison with soluble human insulin in normal subjects. BMJ 1988; 297:1236-9. [PMID: 3145064 PMCID: PMC1834710 DOI: 10.1136/bmj.297.6658.1236] [Citation(s) in RCA: 32] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
OBJECTIVE To compare the rate of absorption from subcutaneous tissue and the resulting hypoglycaemic effect of iodine-125 labelled soluble human insulin and a monomeric insulin analogue derived by recombinant DNA technology. DESIGN Single blind randomised comparison of equimolar doses of 125I labelled soluble human insulin and insulin analogue. SETTING Study in normal people at a diabetes research unit and a university department of medical physics. SUBJECTS Seven healthy male volunteers aged 20-39 not receiving any other drugs. INTERVENTIONS After an overnight fast and a basal period of one hour two doses (0.05 and 0.1 U/kg) of 125I labelled soluble human insulin and insulin analogue were injected subcutaneously into the anterior abdominal wall on four separate days. END POINT To find a fast acting insulin for meal related requirements in insulin dependent diabetics. MEASUREMENTS and main results--Residual radioactivity at the injection site was measured continuously for the first two hours after injection of the 125I labelled preparations and thereafter for five minutes simultaneously with blood sampling. Frequent venous blood samples were obtained over six hours for determination of plasma immunoreactive insulin, insulin analogue, glucose, and glucagon values. Time to 50% of initial radioactivity at the injection site for the insulin analogue compared with soluble insulin was 61 v 135 minutes (p less than 0.05) with 0.05 U/kg and 67 v 145 minutes (p less than 0.001) with 0.1 U/kg. Concentrations in plasma increased faster after the insulin analogue compared with soluble insulin, resulting in higher plasma concentrations between 10 and 150 minutes (0.001 less than p less than 0.05) after 0.05 U/kg and between 40 and 360 minutes (0.001 less than p less than 0.05) after 0.1 U/kg. The hypoglycaemic response to insulin analogue was a plasma glucose nadir at 60 minutes with both doses compared with 90 and 120 minutes with soluble insulin at 0.5 and 0.1 U/kg respectively. The response of glucagon substantiated the earlier and more dramatic hypoglycaemic effect with the insulin analogue. CONCLUSIONS The much faster absorption from subcutaneous tissue of the disubstituted monomeric insulin analogue compared with soluble insulin suggests that the analogue may be a potential candidate for rapid insulin delivery after subcutaneous bolus injection.
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Affiliation(s)
- J P Vora
- Department of Medicine, University of Wales College of Medicine, Health Park, Cardiff
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775
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Kang S, Niemetz J. Purification of human brain tissue factor. Thromb Haemost 1988; 59:400-3. [PMID: 3187930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Tissue factor (thromboplastin or Factor III), a glycoprotein cofactor, is required for Factor VII to express its catalytic activity, thereby initiating the extrinsic as well as intrinsic pathway of blood coagulation. Human brain tissue factor was purified 2,500-fold to 98% homogeneity from 2% Triton X-100 extraction of acetone dried brain powder with an overall yield of 36%. The method was based upon affinity chromatography utilizing the high affinity binding of tissue factor to Factor VII noncovalently complexed to immobilized anti-Factor VII-agarose beads. The apparent molecular weight of the purified tissue factor is 45,000 as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and its isoelectric point is 4.8-5.1 by column chromatofocussing and flat bed agarose isoelectric focussing.
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Affiliation(s)
- S Kang
- Mount Sinai School of Medicine, New York, NY
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776
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Mizuno S, Kang S, Lee H, Trapani J, Yang S. Isolation and expression of a cDNA clone encoding an HLA-Cw6 gene. Hum Immunol 1988. [DOI: 10.1016/0198-8859(88)90212-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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777
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Ellis CN, Kang S, Vinik AI, Grekin RC, Cunningham WJ, Voorhees JJ. Glucose and insulin responses are improved in patients with psoriasis during therapy with etretinate. Arch Dermatol 1987; 123:471-5. [PMID: 3548599] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Since lipemia is commonly induced by retinoid therapy, we investigated the effects of etretinate administration on glucose metabolism by obtaining five-hour oral glucose tolerance tests in 23 patients before and after 20 weeks of etretinate therapy for psoriasis. Compared with pretreatment values, peak and aggregate levels for serum glucose and aggregate levels for serum insulin were significantly lower during therapy. The changes were not associated with obesity, weight loss during treatment, or pretherapy glucose tolerance or insulin secretion level. Of 11 patients with impaired or diabetic glucose tolerance prior to therapy, eight patients had improved glucose tolerance after 20 weeks of etretinate treatment. Despite inducing hypertriglyceridemia in most patients, etretinate therapy is associated with a reduction in glucose levels in response to a glucose load.
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778
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Kang S, Ellis CN, Grekin RC, Hamilton TA, Voorhees JJ, LoBuglio AF. Etretinate therapy and immune activities. Arch Dermatol 1986; 122:629-30. [PMID: 3717974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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779
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780
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781
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Ellis CN, Fallon JD, Kang S, Vanderveen EE, Voorhees JJ. Topical application of nonsteroidal anti-inflammatory drugs prevents vehicle-induced improvement of psoriasis. J Am Acad Dermatol 1986; 14:39-43. [PMID: 3950112 DOI: 10.1016/s0190-9622(86)70004-2] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In a double-blind fashion, we compared the effect of topical application of 1% indomethacin cream or 1% meclofenamate cream with the effect of vehicle therapy alone in thirty patients with psoriasis. After 4 weeks' treatment of bilaterally symmetric psoriatic plaques, the indomethacin-treated sides were worse than the vehicle-treated sides in fourteen of twenty patients (p less than 0.01); the meclofenamate-treated sides were worse than the vehicle-treated sides in seven of ten patients (p less than 0.05). We suspect that the nonsteroidal anti-inflammatory drugs contributed to the maintenance of our patients' psoriasis by altering the arachidonic acid transformation cascade.
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782
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783
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Ellis CN, Kang S, Grekin RC, Voorhees JJ, Silva J. Etretinate therapy reduces polymorphonuclear leukocyte chemotaxis--enhancing properties of psoriatic serum. J Am Acad Dermatol 1985; 13:437-43. [PMID: 4056118 DOI: 10.1016/s0190-9622(85)70186-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Using a Boyden chamber technic, we measured the directed chemotaxis of polymorphonuclear leukocytes obtained from control subjects or psoriasis patients when the leukocytes were placed in sera obtained from control subjects or psoriasis patients. The samples from patients were obtained before therapy and after 2 and 4 weeks of etretinate administration. Compared with control sera, the sera from seven untreated psoriasis patients significantly enhanced the chemotaxis of polymorphonuclear leukocytes from control subjects toward a chemotaxin (p less than 0.05). After 4 weeks of etretinate therapy, the chemotaxis-stimulating ability of the sera from psoriasis patients was no longer significantly greater than that of the control sera. This decline in the chemotaxis-stimulating activity of our patients' sera preceded significant clearing of their psoriasis. The levels of circulating etretinate in the blood of our patients could not account for the reduction. Etretinate therapy had no apparent direct effect on the chemotactic activity of polymorphonuclear leukocytes from the psoriasis patients but may act in part by reducing the inflammatory effects of psoriatic sera.
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784
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Ellis CN, Kang S, Grekin RC, LoBuglio AF, Voorhees JJ. Etretinate therapy for psoriasis. Reduction of antibody-dependent cell-mediated cytotoxicity of polymorphonuclear leukocytes. Arch Dermatol 1985; 121:877-80. [PMID: 4015133 DOI: 10.1001/archderm.121.7.877] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We monitored the antibody-dependent cell-mediated cytotoxicity of polymorphonuclear leukocytes from 14 patients with psoriasis before and during etretinate therapy. Neutrophils obtained from the patients with psoriasis at pretherapy demonstrated significantly greater cytotoxic activity than control cells. After four weeks of etretinate therapy, the cytotoxicity of neutrophils from the psoriatic patients decreased significantly and was no longer significantly different from the control value (at a 1:1 effector-to-target ratio). The decline in neutrophil cytotoxicity preceded significant clearing of our patients' psoriasis. The reduction in the antibody-dependent cell-mediated cytotoxicity of polymorphonuclear leukocytes from patients with psoriasis occurs early during therapy and may represent one of the mechanisms of action of etretinate.
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785
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Abstract
A case of extensive bone and joint tuberculosis is reported in a 62-year-old caucasian woman who had a 25 year history of inadequately treated facial lupus vulgaris. In spite of a good response to standard anti-tuberculosis chemotherapy there was extensive residual joint destruction.
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786
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Abstract
A prospective evaluation of the efficacy and safety of oral ibuprofen and tetracycline hydrochloride was conducted for 8 weeks in patients with moderately severe acne. Sixty-eight patients were randomly assigned in a double-blind fashion to one of four regimens: (1) one 600 mg ibuprofen tablet plus one 250 mg tetracycline capsule four times daily; (2) one 600 mg ibuprofen tablet plus one placebo capsule four times daily; (3) one 250 mg tetracycline capsule plus one placebo tablet four times daily; and (4) one placebo tablet and one placebo capsule four times daily. Sixty patients completed the 8-week study. The mean percent improvement in the groups treated with ibuprofen and tetracycline (56% +/- 5 SE), ibuprofen alone (26% +/- 13 SE), or tetracycline alone (26% +/- 9 SE) was statistically significant. However, only the combination of ibuprofen and tetracycline therapy had an effect statistically better than the placebo response (16+ +/- 11 SE). Adverse effects were transient and were similar in all four groups.
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787
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Cailletaud G, Nouailhas D, Grattier J, Levaillant C, Mottot M, Tortel J, Escavarage C, Héliot J, Kang S. A review of creep-fatigue life prediction methods: identification and extrapolation to long term and low strain cyclic loading. Nuclear Engineering and Design 1984. [DOI: 10.1016/0029-5493(84)90121-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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788
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Abstract
Minoxidil, a potent peripheral vasodilator used orally for refractory hypertension, has produced hypertrichosis. To determine the efficacy and safety of 1% or 5% topical minoxidil for the stimulation of scalp hair regrowth, we studied fifteen normotensive patients, five with androgenic alopecia and ten with alopecia areata diagnosed clinically and by biopsy, for 12 months. Three of five patients with androgenic alopecia using 5% minoxidil for 12 months noted hair regrowth, ranging from minimally observable hair to an appreciable restoration of larger, pigmented, terminal hair in one patient. Among the patients with androgenic alopecia, regrowth response corresponded to the serum minoxidil blood levels. None of the patients with alopecia areata receiving either 1% or 5% minoxidil noted hair regrowth despite comparable minoxidil blood levels. Improved local absorption of topical minoxidil solution may promote hair regrowth in androgenic alopecia.
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789
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Muhlfelder TW, Niemetz J, Kang S. GLucocorticoids inhibit the generation of leukocyte procoagulant (tissue factor) activity. Blood 1982; 60:1169-72. [PMID: 7126870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
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790
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Kang S, Maelicke A. Fluorescein isothiocyanate-labeled alpha-cobratoxin. Biochemical characterization and interaction with acetylcholine receptor from Electrophorus electricus. J Biol Chem 1980; 255:7326-32. [PMID: 6771288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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791
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Kang S, Maelicke A. Fluorescein isothiocyanate-labeled alpha-cobratoxin. Biochemical characterization and interaction with acetylcholine receptor from Electrophorus electricus. J Biol Chem 1980. [DOI: 10.1016/s0021-9258(20)79707-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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792
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Kang S, Ernst L, Weinstein H, Osman R. [13C]NMR chemical shifts and calculated electronic structures of serotonin congeners: relation to biological activity. Mol Pharmacol 1979; 16:1031-9. [PMID: 530246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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793
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794
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795
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Kang S, Bergamini MV, Hasen M. Conformation of N-formyl-1,3-dihydroxy-delta31-pentene, a model compound of sphingomyelin. J Theor Biol 1976; 63:117-24. [PMID: 1003987 DOI: 10.1016/0022-5193(76)90088-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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796
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Weinstein H, Chou D, Johnson CL, Kang S, Green JP. Tautomerism and the receptor action of histamine: a mechanistic model. Mol Pharmacol 1976; 12:738-45. [PMID: 995124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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797
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Abstract
Classical potential function calculations were carried out on the hypothalamic factor Pro-Leu-Gly-NH2. The results indicate that the proposed 10-membered, hydrogen-bonded beta-turn conformation of this tripeptide is a strongly preferred structure. Its stability appears to be inherent in the rather rigid backbone conformation of the leucine residue rather than the hydrogen bond between the carboxamide proton of glycinamide and the C=O of the proline moiety; the glycinamide has little influence on the phi-psi of the leucine backbone structure. The type II beta-turn structure of the Pro-Leu-Gly-NH2 is preferred.
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798
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Kang S, Chou D. Tautomerism of histamine. Chem Phys Lett 1975. [DOI: 10.1016/0009-2614(75)87032-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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799
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800
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Honda M, Nakamura K, Toyota H, Kang S, Seki M. [Postoperative follow-up of pulmonary hypertension with congenital heart diseases]. Nihon Kyobu Geka Gakkai Zasshi 1974; 22:428-9. [PMID: 4474210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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