1026
|
Yang DJ, Xu SF, Xu DZ, Liu GL, Xu JL, Li JM, Chen T, Lu ZQ. Nasal mucociliary function in normal adults and different nasal diseases. Chin Med J (Engl) 1986; 99:969-72. [PMID: 3105976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
|
1027
|
Gesundheit N, Magner JA, Chen T, Weintraub BD. Differential sulfation and sialylation of secreted mouse thyrotropin (TSH) subunits: regulation by TSH-releasing hormone. Endocrinology 1986; 119:455-63. [PMID: 2426082 DOI: 10.1210/endo-119-2-455] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
To determine whether sulfate and/or sialic acid are present on secreted mouse TSH, thyrotropic tumor minces and hypothyroid pituitaries were incubated with [3H]methionine and [35S]sulfate, or [35S]methionine and [3H]N-acetylmannosamine. The metabolically labeled TSH and free alpha-subunits were then analyzed by gel electrophoresis. [3H]N-Acetylmannosamine was a specific precursor (greater than 80%) for the sialic acid [3H]N-acetylneuraminic acid, as established by HPLC characterization of tritium label released by acid hydrolysis. Each of the three secreted subunits (TSH alpha, TSH beta, and free alpha) incorporated both sulfate and sialic acid. The incorporation of these labels was confirmed by the release of [35S]sulfate by endoglycosidase F and of [3H]N-acetylneuraminic acid by neuraminidase. Differential labeling of newly synthesized secreted TSH subunits was observed. In secreted TSH dimer, TSH beta incorporated 1.3 times more [35S]sulfate (P less than 0.05) and 2.5 times more [3H] N-acetylmannosamine (P less than 0.02) per carbohydrate chain than did TSH alpha. Secreted free alpha-subunit incorporated more [3H]N-acetylmannosamine, but less [35S]sulfate, then did secreted TSH alpha. To investigate the effect of TRH on TSH sulfation and sialylation, thyrotropic tumor minces and hypothyroid pituitaries were incubated with [35S]sulfate or [3H]N-acetylmannosamine, with or without 10(-7) M TRH; labeling was then normalized in each case to incorporation of [3H]mannose, a marker of the inner core sugars. TSH secreted in the presence of TRH had a lower sulfate to mannose ratio [28 +/- (+/- SE) 4% of control; P less than 0.05] and a lower sialic acid to mannose ratio (63 +/- 8% of control; P less than 0.05). TSH alpha and TSH beta were affected equally. No change was seen in the labeling of non-TSH secretory proteins. Differential glycoprotein sulfation and sialylation may, in part, explain the previously observed variability in isoelectric point, bioactivity, and MCR of TSH in different physiological states and may represent a point of regulation by TRH.
Collapse
|
1028
|
Chedid A, Mendenhall CL, Tosch T, Chen T, Rabin L, Garcia-Pont P, Goldberg SJ, Kiernan T, Seeff LB, Sorrell M. Significance of megamitochondria in alcoholic liver disease. Gastroenterology 1986; 90:1858-64. [PMID: 3699404 DOI: 10.1016/0016-5085(86)90253-2] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The significance of megamitochondria in the alcoholic liver injury of humans was investigated as part of a large Veterans Administration cooperative study of the natural history of alcoholic hepatitis. Two hundred twenty patients were clinically stratified into the following three groups according to disease severity using serum bilirubin and prothrombin time as indicators: Group 1 (mild disease), serum bilirubin levels less than 5 mg/dl and prothrombin time prolonged for less than 4 s; group 2 (moderate disease), serum bilirubin levels greater than 5 mg/dl but prothrombin time prolonged for less than 4 s; and group 3 (severe disease), serum bilirubin levels greater than 5 mg/dl and prothrombin time prolonged for greater than 4 s. Megamitochondria were observed in 20% of the patients (45 of 220). Of these, 43 patients were in groups 1 and 2 of severity and only 1 patient belonged in group 3. The association of megamitochondria with cirrhosis was infrequent (33%, 15 of 45 patients). The differences in severity correlated with the differences in mortality: in patients with megamitochondria, only 1 had died at 6 mo compared with 40 deaths in patients without megamitochondria. By 12 mo, there were two deaths in patients with megamitochondria versus 51 deaths in those patients without. No complications were present in 72% of patients with megamitochondria versus 39% for those without. Infection, gastrointestinal bleeding, pancreatitis, hyperglycemia, azotemia, delirium tremens, seizures, and hepatic encephalopathy were all more common in patients without megamitochondria. The patients with megamitochondria appear to represent a subcategory of alcoholic hepatitis with a milder degree of clinical severity, lower incidence of cirrhosis, fewer complications, and good long-term survival.
Collapse
MESH Headings
- Biopsy, Needle
- Endoplasmic Reticulum/pathology
- Hepatitis, Alcoholic/complications
- Hepatitis, Alcoholic/mortality
- Hepatitis, Alcoholic/pathology
- Humans
- Liver/pathology
- Liver Cirrhosis, Alcoholic/complications
- Liver Cirrhosis, Alcoholic/mortality
- Liver Cirrhosis, Alcoholic/pathology
- Liver Diseases, Alcoholic/complications
- Liver Diseases, Alcoholic/mortality
- Liver Diseases, Alcoholic/pathology
- Microscopy, Electron
- Mitochondria, Liver/pathology
- Mitochondrial Swelling
- Necrosis
- Time Factors
Collapse
|
1029
|
Piraino BM, Rault R, Greenberg A, Dominguez JH, Wallia R, Houck P, Segre GV, Chen T, Foti FM, Puschett JB. Spontaneous hypercalcemia in patients undergoing dialysis. Etiologic and therapeutic considerations. Am J Med 1986; 80:607-15. [PMID: 3963041 DOI: 10.1016/0002-9343(86)90815-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Ten dialysis-treated patients with hypercalcemia (11.5 +/- 0.3 mg/dl, mean +/- SE) due to renal osteodystrophy were compared with 30 control dialysis-treated patients who were not hypercalcemic (9.5 +/- 0.1 mg/dl). The hypercalcemic patients were more disabled than the control patients. Fifty percent of the hypercalcemic patients and 37 percent of the control patients had a mineralization defect (p greater than 0.6). In the control group, intact parathyroid hormone level was significantly higher in patients with osteitis fibrosa than in those with osteomalacia (247 +/- 39 pg/ml versus 60 +/- 20 pg/ml, respectively, p less than 0.005) whereas in the hypercalcemic patients, parathyroid hormone measurements did not discriminate between these two types of bone disease. Osteomalacia was more severe and bone aluminum staining was stronger in the hypercalcemic patients than in the control patients (2.02 +/- 0.47 versus 0.35 +/- 0.11 mm/mm2 tissue area, p less than 0.001). The mean serum calcium level fell from 11.2 +/- 0.2 mg/dl to 10.5 +/- 0.3 mg/dl (p less than 0.01) in eight hypercalcemic patients treated with 24,25-dihydroxyvitamin D. It is concluded that hypercalcemia in patients undergoing dialysis is associated with an increase in bone aluminum level, and with more severe osteomalacia. Intact parathyroid hormone levels are useful for predicting bone histomorphometric parameters but only when hypercalcemia is not present. The drug, 24,25-dihydroxyvitamin D, was effective in lowering the serum calcium level.
Collapse
|
1030
|
Abboud TK, Kim SH, Henriksen EH, Chen T, Eisenman R, Levinson G, Shnider SM. Comparative maternal and neonatal effects of halothane and enflurane for cesarean section. Acta Anaesthesiol Scand 1985; 29:663-8. [PMID: 4072589 DOI: 10.1111/j.1399-6576.1985.tb02277.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The effects of placental transfer of enflurane and halothane were studied in 81 women undergoing cesarean sections. All patients had rapid sequence induction using thiopental, succinylcholine, and endotracheal intubation. They were then randomly assigned to one of five groups: Group I (n = 16) received N2O and oxygen, Group II (n = 16) N2O, oxygen, and 0.25% halothane, Group III (n = 18) N2O, oxygen, and 0.5% halothane, Group IV (n = 18) N2O, oxygen, and 0.5% enflurane, Group V (n = 13) N2O, oxygen, and 1% enflurane. At delivery, blood was drawn from the maternal artery, umbilical vein and artery for measurement of the halogenated agents using gas chromatography. The neonates were evaluated by Apgar scores, umbilical artery and vein acid base status and the Early Neonatal Neurobehavioral Scores (ENNS) at 2 and 24 h of age. Blood loss and the incidence of maternal awareness were also determined. The umbilical vein to maternal vein ratio was approximately 0.5 and 0.6 for enflurane and halothane, respectively. The umbilical artery to umbilical vein ratio was 0.5 with both agents; higher inspired anesthetic concentrations produced higher blood levels. All neonates had Apgar scores of 8 or more at 5 min with the exception of one neonate in the N2O group. Maternal and neonatal acid base status, blood loss, and ENNS were not affected by the addition of the halogenated agents. Of the patients who had N2O alone, 12% had awareness versus none in the other groups. These data demonstrate that low dose halothane or enflurane decreases the incidence of maternal awareness and does not adversely affect the neonate.
Collapse
|
1031
|
Chen T, Applegate D, Reisler E. Cross-linking of actin to myosin subfragment 1 in the presence of nucleotides. Biochemistry 1985; 24:5620-5. [PMID: 3878158 DOI: 10.1021/bi00341a050] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Chemical cross-linking of actin to the 20K and 50K fragments of tryptically cleaved myosin subfragment 1 (S-1) by the zero-length cross-linking reagent 1-ethyl-3-[3-dimethylamino)propyl]carbodiimide (EDC) was used as a probe of the acto-S-1 interface in the presence of nucleotides. The course of the two reactions was monitored by measuring on sodium dodecyl sulfate (SDS)-polyacrylamide gels the time-dependent formation of the 20K-actin and 50K-actin cross-linked products. Both reactions were inhibited somewhat in the presence of MgADP, were slowed 3-4-fold in the presence of magnesium 5'-adenylyl imidodiphosphate (MgAMPPNP), and proceeded at least 7-fold slower with N,N'-p-phenylenedimaleimide (pPDM) modified S-1, as compared to the respective rates in the absence of nucleotides. However, neither the binding of the nucleotides MgADP and MgAMPPNP to S-1 nor the modification of S-1 by pPDM significantly changed the ratio of the cross-linking rates of actin to the 20K and 50K fragments. Similar to what was previously observed in the absence of nucleotides [Chen, T., Applegate, D., & Reisler, E. (1985) Biochemistry 24, 137-144], actin was cross-linked at an approximately 3-fold faster rate to the 20K fragment than to the 50K fragment under all reaction conditions tested. Thus, irrespective of the extent of acto-S-1 dissociation or the binding of nucleotides to acto-S-1, the 20K fragment remains the preferred cross-linking site for actin. These results show that the interaction of actin with each of the cross-linking sites on S-1 is not under selective or preferential control by nucleotides.
Collapse
|
1032
|
Salen G, Horak I, Rothkopf M, Cohen JL, Speck J, Tint GS, Shore V, Dayal B, Chen T, Shefer S. Lethal atherosclerosis associated with abnormal plasma and tissue sterol composition in sitosterolemia with xanthomatosis. J Lipid Res 1985; 26:1126-33. [PMID: 4067433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Tissue sterol composition was determined in an 18-year-old male with sitosterolemia with xanthomatosis who died suddenly and whose coronary and aortic vessels showed extensive atherosclerosis and, for comparison, in an 18-year-old male with minimal atherosclerosis who died accidently. Sterols in the control tissues (plasma, erythrocytes, cardiac muscle, lung, liver, aorta, and brain) contained cholesterol with only trace amounts of cholestanol. In contrast, sterols in corresponding tissues of the sitosterolemic subject (except brain) were composed of cholesterol, increased amounts of plant sterols, campesterol and sitosterol, and 5 alpha-saturated stanols, cholestanol, 5 alpha-campestanol, and 5 alpha-sitostanol, that were deposited in approximately the same ratio as present in plasma. However, sitosterolemic brain sterol composition resembled that of the control brain with cholesterol and only trace amounts (less than 1%) of cholestanol and phytosterols. The sitosterolemic aorta was extensively atherosclerotic and contained more than twice the quantity of sterols as the control aorta (5.6 mg/g versus 2.6 mg/g) with increased amounts of cholesterol, plant sterols, and 5 alpha-saturated stanols. These results indicate that cholesterol, plant sterols, and 5 alpha-stanols are deposited prematurely and are associated with accelerated atherosclerosis in subjects with sitosterolemia with xanthomatosis.
Collapse
|
1033
|
Jaffe N, Robertson R, Ayala A, Wallace S, Chuang V, Anzai T, Cangir A, Wang YM, Chen T. Comparison of intra-arterial cis-diamminedichloroplatinum II with high-dose methotrexate and citrovorum factor rescue in the treatment of primary osteosarcoma. J Clin Oncol 1985; 3:1101-4. [PMID: 3874932 DOI: 10.1200/jco.1985.3.8.1101] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
A randomized two-arm study was undertaken to determine relative tumoricidal effects of intra-arterial cis-diamminedichloroplatinum II (I/A-CDP) and high-dose methotrexate with citrovorum factor rescue (MTX-CF) in the treatment of the primary tumor in patients with osteosarcoma. Responses were evaluated by clinical, radiographic, angiographic, and pathologic parameters. Fifteen patients were randomized to receive MTX-CF and 15 to I/A-CDP. In the MTX-CF arm there were four responses (three complete responses, one partial response) whereas in the I/A CDP arm there were nine responses (seven complete responses, two partial responses). Two patients who failed MTX-CF and requested alternative treatment with I/A-CDP also responded. The total I/A-CDP response was 11/17.
Collapse
|
1034
|
Chen T. [Development and present status of a leptospiral vaccine and the technology of vaccine production in China]. Nihon Saikingaku Zasshi 1985; 40:755-62. [PMID: 3903244 DOI: 10.3412/jsb.40.755] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
|
1035
|
Hewlett JS, Chen T, Balcerzak SP, Gutterman JU, Costanzi JJ, Amare M. High rate of long-term survival in adult acute leukemia following ten-day chemotherapy (OAP) induction. Maintenance with chemotherapy or chemotherapy plus BCG vaccine. ARCHIVES OF INTERNAL MEDICINE 1985; 145:1006-12. [PMID: 3890786] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
In this Southwest Oncology Group (SWOG) study, 216 adults with acute leukemia were treated with ten-day chemotherapy consisting of vincristine sulfate (Oncovin), cytarabine (ara-C) (100 mg per square meter of body area per day by 24-hour infusion), and prednisone (ten-day OAP). The results were compared with those of a previous SWOG study in which cytarabine (200 mg per square meter of body area per day) was given for five days (five-day OAP). Patients entering complete remission (CR) were given three consolidation courses of five-day OAP and randomized to maintenance chemotherapy alone (32 patients) or combined with BCG vaccine (24 patients). For 160 previously untreated patients with acute myelogenous leukemia, there was no difference in remission rates (53% vs 43%) or median survival times (48 vs 47 weeks) between ten-day and five-day OAP. The difference in duration of CR (74 vs 54 weeks, respectively) between the two maintenance arms was not statistically significant. However, 14% of evaluable patients with acute myelogenous leukemia and 26% of those achieving CR were alive and in remission more than five years.
Collapse
|
1036
|
Wolf EL, Chen T, Burnell DM. Further evidence for tunneling anisotropy in Nb crystals. PHYSICAL REVIEW. B, CONDENSED MATTER 1985; 31:6096-6098. [PMID: 9936616 DOI: 10.1103/physrevb.31.6096] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
|
1037
|
Chen T. [A brief analysis of population pressure on agricultural production under the new situation]. REN KOU YAN JIU = RENKOU YANJIU 1985:5-7. [PMID: 12341121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
|
1038
|
Chen T, Applegate D, Reisler E. Cross-linking of actin to myosin subfragment 1: course of reaction and stoichiometry of products. Biochemistry 1985; 24:137-44. [PMID: 3846455 DOI: 10.1021/bi00322a019] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The cross-linking of actin to myosin subfragment 1 (S-1) with 1-ethyl-3-[3-(dimethyl-amino)propyl]carbodiimide was reexamined by using two cross-linking procedures [Mornet, D., Bertrand, R., Pantel, P., Audemard, E., & Kassab, R. (1981) Nature (London) 292, 301-306; Sutoh, K. (1983) Biochemistry 22, 1579-1585] and two independent methods for quantitating the reaction products. In the first approach, the cross-linked acto-S-1 complexes were cleaved with elastase at the 25K/50K and 50K/22K junctions in S-1. This enabled direct measurements of the cross-linked and un-cross-linked fractions of the 50K and 22K fragments of S-1. We found that in all cases actin was preferentially cross-linked to the 22K fragment and that the overall stoichiometry of the main cross-linked products was that of a 1:1 complex of actin and S-1. In the second approach, actin was cross-linked to tryptically cleaved S-1, and the course of these reactions was monitored by measuring the decay of the free 50K and 20K fragments and the formation of cross-linked products. After selecting the optimal cross-linking procedure and conditions, we determined that the rate of actin cross-linking to the 20K fragment of S-1 was 3-fold faster than the reaction with the 50K peptide. The overall rate of cross-linking actin to S-1 corresponded to the sum of the individual reactions of the 50K and 20K fragments, indicating their mutually exclusive cross-linking to actin. Thus, the reactions with tryptically cleaved S-1 were consistent with the 1:1 stoichiometry of actin and S-1 in the main cross-linked products and verified the preferential cross-linking of actin to the 20K fragment of S-1. These results are discussed in the context of the binding of actin to S-1.
Collapse
|
1039
|
Inamasu M, Oishi N, Chen T, Legha S, McCracken J, Balcerzak S, Stephens R, O'Bryan R, Rivkin SE, Costanzi JJ. Phase II trial of amsacrine in pancreatic carcinoma: a Southwest Oncology Group study. CANCER TREATMENT REPORTS 1984; 68:1411-2. [PMID: 6548661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
|
1040
|
Hochberg Z, Benderli A, Levy J, Vardi P, Weisman Y, Chen T, Feldman D. 1,25-Dihydroxyvitamin D resistance, rickets, and alopecia. Am J Med 1984; 77:805-11. [PMID: 6548607 DOI: 10.1016/0002-9343(84)90516-3] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Two unrelated kindreds with four affected children having 1,25-dihydroxyvitamin D resistance, rickets, and alopecia are described. The children exhibited early onset of severe rickets with hypocalcemia, hypophosphatemia, elevated serum alkaline phosphatase levels, and secondary hyperparathyroidism. Radiography showed diffuse demineralization and classic changes of rickets. All affected children had total-body alopecia. Serum levels of 1,25-dihydroxyvitamin D3 were elevated and rose to extremely high values during treatment, with no apparent change in the mineral disorder. However, secondary hyperparathyroidism and hypophosphatemia did remit during treatment despite persistently low calcium levels. Skin biopsy was performed in the parents and affected children in one kindred. Analysis of 1,25-dihydroxyvitamin D3 receptors in cultured fibroblasts indicated apparent normal receptors in the parents and undetectable receptors in both affected children. After long periods of treatment with vitamin D metabolites and mineral replacement, healing took place in the older child in each kindred. These data suggest that the healing occurred spontaneously as the children reached seven to nine years of age rather than as a result of the treatment. The biochemical lesion in these children appeared to be a genetically transmitted defect in the 1,25-dihydroxyvitamin D3 receptor. The mechanisms by which healing was initiated and maintained remain to be elucidated.
Collapse
|
1041
|
Bennett A, Chen T, Feldman D, Hintz RL, Rosenfeld RG. Characterization of insulin-like growth factor I receptors on cultured rat bone cells: regulation of receptor concentration by glucocorticoids. Endocrinology 1984; 115:1577-83. [PMID: 6090106 DOI: 10.1210/endo-115-4-1577] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A specific receptor for insulin-like growth factor I (IGF-I) has been demonstrated in cultured fetal rat osteoblast-like bone cells. Specific binding of [125I]IGF-I to bone cells incubated at 15 C reached a steady state by 5 h. Half-maximal inhibition of [125I]IGF-I binding by unlabeled IGF-I was observed at 7 ng/ml. Multiplication-stimulating activity, insulin, and proinsulin were less effective than unlabeled IGF-I in competing for receptor occupancy. Scatchard analysis showed a curvilinear plot, with a Ka similar to that observed in human fibroblasts. Incubation of cell monolayers with glucocorticoids resulted in a concentration-dependent increase in [125I]IGF-I binding. This increase in [125I]IGF-I binding was dependent on cell density. After a 2-day exposure to dexamethasone, no increase in binding was observed in sparsely plated cells; however, an increase in binding was observed after 3 days in culture (log phase) and was maximal by 5 days (peak log phase). These data indicate that rat bone cells possess a specific receptor for IGF-I with binding characteristics similar to those reported in human fibroblasts, and that IGF-I receptor concentrations are increased by exposure to glucocorticoids. A role for glucocorticoids and IGF-I in rat bone proliferation is suggested by these findings.
Collapse
|
1042
|
Socol ML, Tamura RK, Sabbagha RE, Chen T, Vaisrub N. Diminished biparietal diameter and abdominal circumference growth in twins. Obstet Gynecol 1984; 64:235-8. [PMID: 6738957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Forty-three women with uncomplicated twin pregnancies and reliable menstrual dates had serial ultrasonic measurements of the fetal biparietal diameter (BPD) and abdominal circumference. The 25th, 50th, and 75th fetal BPD and abdominal circumference growth percentiles were generated from this normal twin population and compared with those for singletons. A slowing of both BPD and abdominal circumference growth in twins was noted in the third trimester. However, newborn anthropometric data were collected that suggest that the head circumference of twins is comparable to that of singletons. This discrepancy between ultrasonic BPD and neonatal head circumference in predicting head size may possibly be explained by dolichocephaly attributed to uterine crowding. For the antenatal assessment of growth in twins the authors recommend the use of BPD and abdominal circumference charts derived specifically from such uncomplicated twin pregnancies. When the BPD growth is abnormal, the head circumference and abdominal circumference should be measured to assess whether or not fetal growth is normal.
Collapse
|
1043
|
Chen T, Reisler E. Tryptic digestion of rabbit skeletal myofibrils: an enzymatic probe of myosin cross-bridges. Biochemistry 1984; 23:2400-7. [PMID: 6477873 DOI: 10.1021/bi00306a013] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Tryptic digestion of rabbit skeletal myofibrils under physiological ionic strength and pH conditions was used as a probe of cross-bridge interaction with actin in the presence of nucleotides and pyrophosphate. Under rigor conditions, digestion of myofibrils at 24 degrees C results in the formation of 25K, 110K [heavy meromyosin (HMM)], and light meromyosin (LMM) fragments as the main reaction products. Very little if any 50K peptide is generated in such digestions. In the presence of magnesium pyrophosphate, magnesium 5'-adenylyl imidodiphosphate (MgAMPPNP), and MgATP, the main cleavage proceeds at two positions, 25K and 75K from the N-terminal portion of myosin, yielding the 25K, 50K, and 150K species. The relative amounts of the 50K, 110K, and 150K peptides and the rates of myosin heavy-chain digestion in the presence of pyrophosphate and AMPPNP indicate partial dissociation of myosin from actin. Direct centrifugation measurements of the binding of HMM and subfragment 1 (S-1) to actin in myofibrils confirm that cross-bridges partition between attached and detached states in the presence of these ligands. In the presence of MgADP, HMM and S-1 remain attached to actin at 24 degrees C. However, tryptic digestion of myofibrils containing MgADP is consistent with the existence of a mixed population of attached and detached cross-bridges, suggesting that only one head on each myosin molecule is attached to actin. As shown by tryptic digestion of myofibrils and the measurements of HMM and S-1 binding to actin, nucleotide- and pyrophosphate-induced dissociation of cross-bridges is more pronounced at 4 than at 24 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
1044
|
Greenberg N, Chen T, Crews D. Social status, gonadal state, and the adrenal stress response in the lizard, Anolis carolinensis. Horm Behav 1984; 18:1-11. [PMID: 6706316 DOI: 10.1016/0018-506x(84)90045-x] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Adult males of the small arboreal iguanid lizard, Anolis carolinensis, form social dominance hierarchies when placed in habitats with limited resources. Skin color changes occur during hierarchy formation, most conspicuously in subordinates, who appear darker (more brown) than dominants (more green). Because skin color in this species is under the control of hormones frequently associated with physiological stress, radioimmunoassay of plasma levels of the principal reptilian adrenal steroid, corticosterone, was performed. To examine the influence of gonadal androgen, known to influence the aggression that attends hierarchy formation, lizard pairs were constituted in which one or both members were castrated. Corticosterone levels of intact subordinates were significantly elevated, whereas those of castrated subordinates or dominants showed levels comparable to those of isolates. No significant differences in spermatogenic stage could be detected between intact dominants or subordinates.
Collapse
|
1045
|
Valdivieso M, Cabanillas F, Keating M, Barkley HT, Murphy WK, Burgess MA, Frazier H, Chen T, Bodey GP. Effects of intensive induction chemotherapy for extensive-disease small cell bronchogenic carcinoma in protected environment-prophylactic antibiotic units. Am J Med 1984; 76:405-12. [PMID: 6322584 DOI: 10.1016/0002-9343(84)90658-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Fifty-five patients with extensive-disease small cell bronchogenic carcinoma received three courses of intensive, inpatient, remission induction chemotherapy in (25 patients) or out (30 patients) of protected environment-prophylactic antibiotic (PEPA) units. Chemotherapy consisted of ECHO induction (E = epipodophyllotoxin VP-16-213; C = cyclophosphamide; H = hydroxydaunorubicin; O = Oncovin) and PRIME maintenance (PR = procarbazine; I = ifosfamide; ME = methotrexate). All evaluable patients (22 in the protected environment group and 26 in the control group) had a complete (50 percent in the protected environment group and 54 percent in the control group) or partial (50 percent in the protected environment group and 46 percent in the control group) remission. Median response and survival durations for both treatment groups were similar. The median survival duration of patients with a complete remission favored the protected environment group (16.5 versus 12.67 months; p = 0.20). Two patients (one from each group) are alive and disease-free for more than four years. Myelosuppression was intense and more pronounced in the protected environment group (p less than or equal to 0.01). Infectious complications were less common in patients receiving intravenous prophylactic antibiotics and in those treated with intravenous antibiotics in PEPA units (p less than or equal to 0.04). There were no treatment-related deaths, although treatment might have contributed to the death of three patients in the protected environment group and four in the control group. The administration of intensive ECHO induction chemotherapy to patients with extensive small cell bronchogenic carcinoma produced a high complete remission rate, although there was no significant long-term survival advantage over a program of less intensity. The administration of intravenous prophylactic antibiotics and the use of PEPA units significantly reduced the infectious morbidity of chemotherapy.
Collapse
|
1046
|
Dixon CL, Valdivieso M, Umsawasdi T, Dubois G, Patton D, Chen T, Ali MK, Bodey GP. Small cell bronchogenic carcinoma: factors associated with pneumonia during chemotherapy. J Clin Oncol 1984; 2:201-6. [PMID: 6321688 DOI: 10.1200/jco.1984.2.3.201] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Sixty-five patients with small cell bronchogenic carcinoma were treated with intensive induction chemotherapy and supportive treatment. The clinical course of 43 patients who had pretreatment spirometry and arterial blood gases was studied. Thirteen patients developed pneumonia. Moderate hypoxemia, advanced age, and a low forced expiratory flow 25%-75% were associated with the development of pneumonia. Endobronchial obstruction and neutropenia, other factors associated with infection in cancer patients, appeared to be less important in this patient population.
Collapse
|
1047
|
Knust EJ, Machulla HJ, Baldwin RM, Chen T, Feinendegen LE. Synthesis of, and animal experiments with, N-isopropyl-p-123I-iodo-amphetamine (IMP) and 18F-3-deoxy-3-fluoro-D-glucose (3-FDG) as tracers in brain and heart diagnostic studies. Nuklearmedizin 1984; 23:31-4. [PMID: 6728691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
For the investigation of brain functions 18F-3-deoxy-3-fluoro-D-glucose (3-FDG) and N-isopropyl-p-123I-iodo-amphetamine (IMP) were synthesized and the course of radioactivity measured in several organs of mice. The results can be summarized as follows: IMP is rapidly extracted from the blood and reaches a value of less than 1% g within the first 15 min; 123I-radioactivity in the lungs shows a maximum of 76%/g as soon as half a minute after injection and decreases with a concomitant increase in the liver and brain; The maximum 123I-uptake in the brain of 11%/g is reached after 30 min and levels off at a constant value of 10%/g; 30 min after injection the brain/blood ratio for IMP is about 14; The time course of 3-FDG in the brain has a maximum of 4.8%/g as soon as 5 min after injection and decreases to a constant value of 3%/g within 1 hr; and Accumulation of 18F- radioactivity in the heart reaches a maximum of 14%/g after 1 hr and is eliminated with a half-life of 300 min. Comparative clinical studies with 3-FDG and 3-0-11C-methyl-D-glucose (CMG) have shown that 3-FDG can be considered as a CMG-analogue and thus can be used for the in-vivo determination of local glucose perfusion and transport rates.
Collapse
|
1048
|
Hvizdala E, Berry DH, Chen T, Dyment PG, Kim TH, Steuber CP, Sullivan MP. Impact of the timing of triple intrathecal therapy on remission induction in childhood acute lymphoblastic leukemia: a Pediatric Oncology Group study. MEDICAL AND PEDIATRIC ONCOLOGY 1984; 12:173-7. [PMID: 6374403 DOI: 10.1002/mpo.2950120306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Five weekly doses of triple intrathecal (IT) chemotherapy (methotrexate, hydrocortisone, cytosine arabinoside) starting on day 1 of treatment were added to systemic induction therapy in a regimen (Arm 3) that was compared to three other regimens (Arms 1, 2, and 4) in which central nervous system (CNS) prophylaxis was initiated after complete marrow remission (CR) was attained. The CR rate for Arm 3 was only 83% as compared to 91-92% for other Arms. The lower CR rate was the result of a significantly higher death rate during induction for patients receiving early CNS prophylaxis (10.6 vs 0.9-3.5%). These differences were only observed in high risk patients as defined in the study. The early death rate was especially high (30%) in Arm 3 for children who were less than 2 years of age. Infection was the primary cause of morbidity and mortality. Severe infection following the initiation of induction therapy was found in 16.7% of patients on Arm 3 vs 1.8-6% on other regimens. Immediate triple IT chemoprophylaxis during induction therapy of acute lymphoblastic leukemia as used in this study appears to be associated with increased susceptibility to infection and this form of CNS prophylaxis has increased hazards of morbidity and mortality in infants and other high risk patients.
Collapse
|
1049
|
Baker H, Frank O, Chen T, Feingold S, DeAngelis B, Baker E. Vitamin content of some normal human brain segments. J Neurosci Res 1984; 11:419-35. [PMID: 6235380 DOI: 10.1002/jnr.490110409] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Nicotinates, pantothenates, riboflavin, vitamins B6 and B12' free (acetyl) and total (free and bound) choline, biopterin, thiamin, biotin, methylated and nonmethylated folates in frontal, temporal, precentral, postcentral, and occipital cortex, thalamus, cerebellum, pons, basal ganglia, and substantia nigra were estimated. Nicotinates are significantly more concentrated in basal ganglia and thalamus than pons. Nonmethylated folate content is not significantly varied in brain segments; the pons contains more methylated folate. Riboflavin content is higher in the basal ganglia and temporal cortex than frontal cortex. Biotin is concentrated in pons and basal ganglia. Thiamin concentration is less in the postcentral cortex than the thalamus and substantia nigra. Biopterin is significantly higher in substantia nigra and basal ganglia than the other brain segments. Total choline content is high in substantia nigra, pons, and thalamus; free (acetyl) choline is significantly elevated in basal ganglia. B12 content is less concentrated in the cortex segments. B6 is highly concentrated in the basal ganglia. Pantothenate content is elevated in pons when compared to the various cortex segments and cerebellum.
Collapse
|
1050
|
Von Hoff DD, Chen T, Clark GM, Callahan SK, Livingston R. Mitoxantrone for treatment of patients with refractory small cell carcinoma of the lung: a Southwest Oncology Group Study. CANCER TREATMENT REPORTS 1983; 67:403-404. [PMID: 6303588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
|