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Morrison SL, Canfield S, Porter S, Tan LK, Tao MH, Wims LA. Production and characterization of genetically engineered antibody molecules. Clin Chem 1988. [DOI: 10.1093/clinchem/34.9.1668] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Expression of antibody heavy- and light-chain genes by transfection permits the production of monoclonal antibodies with improved biological and antigen-binding properties. The immunoglobulin genes are placed in vectors containing a gene for encoding a protein that provides a biochemically selectable function in eukaryotic cells; these vectors are transfected into myeloma and hybridoma cells. Selection of drug-resistant cells permits the efficient isolation of the rare cells that express the transfected DNA. By placing heavy and light chains on plasmids with different selectable markers, one can deliver heavy- and light-chain genes simultaneously to the same cell. The transfected immunoglobulin genes are efficiently expressed and the proteins produced are a faithful mirror of the genes that were introduced. Using the standard techniques of genetic engineering and gene transfection, we can now produce antibodies of widely varying structures, including chimeric antibodies with segments derived from different species. These antibodies provide useful reagents to study structure-function relationships within the antibody molecule. Ultimately it will be possible to produce a new generation of antibody molecules with improved antigen-binding properties and effector functions.
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Cheong WY, Wang YY, Tan LK, Cheah ES, Poh SC. Pulmonary alveolar microlithiasis. AUSTRALASIAN RADIOLOGY 1988; 32:401-4. [PMID: 3202757 DOI: 10.1111/j.1440-1673.1988.tb02763.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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103
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Miller AD, Lakos SF, Tan LK. Central motor program for relaxation of periesophageal diaphragm during the expulsive phase of vomiting. Brain Res 1988; 456:367-70. [PMID: 3208085 DOI: 10.1016/0006-8993(88)90241-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Relaxation of the periesophageal diaphragm during expulsion in decerebrate cats was found to arise from central mechanisms rather than a reflex of peripheral origin. Reductions in periesophageal EMG activity during expulsion were similar before and after cervical vagotomy, which abolishes reflex relaxation of the periesophageal diaphragm following esophageal distension. Reduced activity was also observed in a phrenic nerve branch to the periesophageal region during 'fictive vomiting' in a paralyzed animal.
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104
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Kasian GF, Elash JH, Tan LK. Bacteriologic surveillance of indwelling urinary catheters in pediatric intensive care unit patients. Crit Care Med 1988; 16:679-82. [PMID: 3371044 DOI: 10.1097/00003246-198807000-00006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Daily cultures were obtained from the proximal tubing port on 108 indwelling urinary catheters in 100 pediatric ICU (PICU) patients aged 1 month to 17 yr to establish the risk of acquiring bacteriuria. Group 1 patients (58 catheters) were catheterized in the PICU and group 2 patients (50 catheters) were catheterized in the operating room. Group 1 patients had a significantly (p less than .03) greater risk of bacteriuria than group 2 during the early days of surveillance, but the final cumulative risk in both groups was similar (27% in group 1 and 37% in group 2). Combined, the overall cumulative risk was 29.1%. The risk of acquiring a urinary tract infection was not related to sex or prior antibiotic use. There was a significantly greater risk (p less than .025) in children under 1 yr of age.
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105
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Crone LA, Conly JM, Clark KM, Crichlow AC, Wardell GC, Zbitnew A, Rea LM, Cronk SL, Anderson CM, Tan LK. Recurrent herpes simplex virus labialis and the use of epidural morphine in obstetric patients. Anesth Analg 1988. [PMID: 3354864 DOI: 10.1213/00000539-198804000-00004] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A retrospective study of sequential obstetric patients delivering at University Hospital and receiving epidural anesthesia was conducted to determine if a suggested association exists between the recurrence of oral herpes simplex lesions and the use of epidural morphine. In a retrospective study of 291 patients, 13 of 134 (9.7%) receiving epidural morphine developed recurrent oral herpes lesions in contrast to 1 of 157 (0.6%) not receiving the drug (P less than 0.001). In a prospective hospital-based study of 729 consecutive obstetric patients, 146 patients received epidural opioids (morphine, fentanyl, or both) and 583 did not. Recurrent HSVL lesions occurred in 13 of 140 (9.3%) patients given epidural morphine but in only 6 of 583 (1.0%) not given epidural opioids (P less than 0.001). Three of the 13 patients with HSVL received both epidural morphine and fentanyl and 10 received only epidural morphine. Because of the small numbers of patients receiving only fentanyl, no relation between HSVL reactivation and epidural fentanyl could be established. In patients having caesarean sections, the association of recurrent HSVL and the use of epidural morphine was significant (P = 0.04), suggesting cesarean delivery was not a confounder. A hitherto undescribed triggering agent, epidural morphine, appears to be associated with reactivation of HSVL in obstetric patients in the postpartum period.
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106
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Crone LA, Conly JM, Clark KM, Crichlow AC, Wardell GC, Zbitnew A, Rea LM, Cronk SL, Anderson CM, Tan LK. Recurrent herpes simplex virus labialis and the use of epidural morphine in obstetric patients. Anesth Analg 1988; 67:318-23. [PMID: 3354864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
A retrospective study of sequential obstetric patients delivering at University Hospital and receiving epidural anesthesia was conducted to determine if a suggested association exists between the recurrence of oral herpes simplex lesions and the use of epidural morphine. In a retrospective study of 291 patients, 13 of 134 (9.7%) receiving epidural morphine developed recurrent oral herpes lesions in contrast to 1 of 157 (0.6%) not receiving the drug (P less than 0.001). In a prospective hospital-based study of 729 consecutive obstetric patients, 146 patients received epidural opioids (morphine, fentanyl, or both) and 583 did not. Recurrent HSVL lesions occurred in 13 of 140 (9.3%) patients given epidural morphine but in only 6 of 583 (1.0%) not given epidural opioids (P less than 0.001). Three of the 13 patients with HSVL received both epidural morphine and fentanyl and 10 received only epidural morphine. Because of the small numbers of patients receiving only fentanyl, no relation between HSVL reactivation and epidural fentanyl could be established. In patients having caesarean sections, the association of recurrent HSVL and the use of epidural morphine was significant (P = 0.04), suggesting cesarean delivery was not a confounder. A hitherto undescribed triggering agent, epidural morphine, appears to be associated with reactivation of HSVL in obstetric patients in the postpartum period.
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107
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Leong AF, Nambiar R, Tan LK. Cholangiocarcinoma in a choledochal cyst--a case report and review of the literature. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 1988; 17:104-6. [PMID: 2847628] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A rare case of cholangiocarcinoma occurring in a choledochal cyst in an adult woman is reported. Unlike the few previous reports this case was diagnosed pre-operatively and treated radically by an extended Whipple's operation.
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108
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Miller AD, Tan LK. Possible role of brain stem respiratory neurons in mediating vomiting during space motion sickness. AVIATION, SPACE, AND ENVIRONMENTAL MEDICINE 1987; 58:A126-8. [PMID: 2960318] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Vomiting is produced primarily by the coordinated action of the respiratory muscles. The object of this study was to determine if brain stem expiratory neurons control abdominal muscle activity during vomiting. We recorded the activity of 27 ventral respiratory group (VRG) expiratory neurons, which are known to be of primary importance for control of abdominal muscle activity during respiration. During fictive vomiting produced by emetic stimulants in decerebrate, paralyzed cats, only one-third of these neurons had the appropriate firing pattern to contribute to abdominal muscle activity during vomiting. In a second series of experiments, we recorded abdominal muscle activity in five cats before and after cutting the axons of VRG expiratory neurons. Abdominal activity remained at 60-100% of prelesion values in three animals. Thus, abdominal muscle activity during vomiting must be controlled not only by some brain stem expiratory neurons but also by other input(s).
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Miller AD, Tan LK, Suzuki I. Control of abdominal and expiratory intercostal muscle activity during vomiting: role of ventral respiratory group expiratory neurons. J Neurophysiol 1987; 57:1854-66. [PMID: 2955084 DOI: 10.1152/jn.1987.57.6.1854] [Citation(s) in RCA: 86] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The role of ventral respiratory group (VRG) expiratory (E) neurons in the control of abdominal and internal intercostal (expiratory) muscle activity during vomiting was examined in decerebrate cats by recording from these neurons during fictive vomiting in paralyzed animals and comparing abdominal muscle activity during vomiting before and after sectioning the axons of these descending neurons. Fictive vomiting was defined by a series of bursts of coactivation of abdominal and phrenic nerves elicited by either subdiaphragmatic vagus nerve stimulation or emetic drugs. Such coordinated activity would be expected to produce vomiting if the animals were not paralyzed. Data were recorded from 27 VRG E neurons that were antidromically activated from the lower thoracic (T13) or lumbar spinal cord. During fictive vomiting, almost two-thirds of these neurons (17/27) were mainly active in between periods of abdominal and phrenic nerve coactivation, when the internal intercostal motoneurons are known to be active. This group of neurons was termed INT neurons. INT neurons were subdivided according to whether they were active between every burst of phrenic and abdominal nerve coactivation (INTa neurons, n = 10) or only between some bursts (INTb neurons, n = 7). Another one-third of the VRG E neurons had normal or increased levels of activity when the abdominal nerves were active during fictive vomiting (ABD neurons). The one remaining neuron was mainly silent throughout fictive vomiting. ABD neurons were indistinguishable from INT neurons on the basis of their location in the VRG, type of firing pattern (ramp versus step ramp), conduction velocity, or extent of projection in the lumbar cord. However, INTa neurons had a significantly higher discharge rate during respiration than either ABD or INTb neurons. Abdominal muscle EMG and nerve activity were recorded from six unparalyzed cats before and after cutting the axons of VRG E neurons as they cross the midline between C1 and the obex. The lesions abolished or almost eliminated expiratory modulation of abdominal muscle activity. In contrast, the abdominal muscles were always active during vomiting; however, the amplitude of postlesion abdominal activity varied from approximately 70-100% of prelesion values in three cats to 60-70% of normal in a fourth animal to only approximately 20% of prelesion values in two other cats.(ABSTRACT TRUNCATED AT 400 WORDS)
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111
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Poh SC, Wang YT, Tan LK. Systemic to pulmonary artery fistulas in Hodgkin's disease. THE AMERICAN REVIEW OF RESPIRATORY DISEASE 1986; 134:1324-6. [PMID: 3789531 DOI: 10.1164/arrd.1986.134.5.1324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A case of Hodgkin's disease with multiple systemic to pulmonary artery fistulas is described. Despite resolution of the parenchymal infiltrate with combination chemotherapy, the vascular abnormalities persisted. Successful closure of the vascular connections occurred after therapeutic embolization with gel foam and alcohol.
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112
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Abstract
The use of iopamidol and iohexol for lumbar myelography is compared in this study. Fifty-eight patients were examined, the contrast media being allocated on a randomised double-blind basis. Radiographic quality was good with both media. Headache and an increase of back pain were the most frequent symptoms, though the incidence of side-effects was slightly but significantly greater with iohexol. We conclude from our study that while the radiographic quality is comparable, iopamidol seems to be slightly better tolerated.
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113
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Tan LK, Miller AD. Innervation of periesophageal region of cat's diaphragm: implication for studies of control of vomiting. Neurosci Lett 1986; 68:339-44. [PMID: 2944037 DOI: 10.1016/0304-3940(86)90513-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The extent of the region of the diaphragm around the esophagus that displays greatly reduced activity during the expulsive phase of vomiting was determined from electromyographic studies in cats to be about 0.75-1.0 cm from the esophagus. Horseradish peroxidase injected into this region retrogradely labeled motoneurons throughout most of the rostral-caudal extent of the phrenic nucleus, with the exception of caudal C6 and rostral C7. This widespread intermingling of motoneurons that innervate the region of reduced activity with other phrenic motoneurons creates a difficulty for needed follow-up studies of diaphragmatic control during vomiting.
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Wong J, Oh VM, Chia BL, Rauff A, Tan LK. Adrenal phaeochromocytoma and neurofibromatosis presenting with hypotension. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 1986; 15:127-31. [PMID: 2871801] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We report a case of adrenal phaeochromocytoma with the stigmata of neurofibromatosis, who presented with acute hypotension. The patient later had episodes of hypertension alternating with hypotension, associated with electrocardiographic changes simulating myocardial infarction, and finally a completed stroke. The circumstances illustrate the problem of early recognition of the protean clinical effects of an excess of circulating adrenal medullary hormones. They also emphasise the need to consider phaeochromocytoma as a differential diagnosis of apparent clinical shock.
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115
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Tan LK, Oi VT, Morrison SL. A human-mouse chimeric immunoglobulin gene with a human variable region is expressed in mouse myeloma cells. THE JOURNAL OF IMMUNOLOGY 1985. [DOI: 10.4049/jimmunol.135.5.3564] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Abstract
We have constructed and obtained expression of a chimeric human-mouse immunoglobulin gene after transfection into mouse myeloma cells. A human VDJH gene segment was joined to a mouse C kappa gene in the plasmid vector pSV2-gpt, and the construct was transfected into J558L cells by protoplast fusion. Analyses of six transformants by RIA and SDS-PAGE indicated that the chimeric protein was synthesized in large amounts in five. A kappa-specific transcript was observed by Northern blot analysis. Four out of five clones were stable producers of this chimeric chain over a period of 10 mo.
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Tan LK, Oi VT, Morrison SL. A human-mouse chimeric immunoglobulin gene with a human variable region is expressed in mouse myeloma cells. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 1985; 135:3564-7. [PMID: 3930609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
We have constructed and obtained expression of a chimeric human-mouse immunoglobulin gene after transfection into mouse myeloma cells. A human VDJH gene segment was joined to a mouse C kappa gene in the plasmid vector pSV2-gpt, and the construct was transfected into J558L cells by protoplast fusion. Analyses of six transformants by RIA and SDS-PAGE indicated that the chimeric protein was synthesized in large amounts in five. A kappa-specific transcript was observed by Northern blot analysis. Four out of five clones were stable producers of this chimeric chain over a period of 10 mo.
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Abstract
Renal functional abnormalities, occurring before overt renal disease and possibly due to abnormal vascular control mechanisms, have been described in diabetes mellitus. We used intravenous (i.v.) furosemide, which stimulates renal prostaglandin (PG) synthesis and renin release, to compare these vasoactive systems in 14 diabetic and 23 normal control subjects. Using urine thromboxane B2 (TXB2) as an index of renal synthesis of the vasoconstrictor prostanoid TXA2, and urine 6keto-PGF1 alpha for the vasodilator PGI2, we found evidence of increased renal TXA2 synthesis in diabetic subjects in response to furosemide. The increased TXA2 synthesis did not occur at the expense of PGI2 synthesis, as urine 6keto-PGF1 alpha was not reduced. Increased TXB2 excretion in diabetic subjects was particularly marked in the first 10 min after i.v. furosemide. During this time, diabetic males excreted 31 +/- 6 ng of TXB2 compared with 10 +/- 1 ng for normal males (P less than 0.05), while diabetic females excreted 15 +/- 3 ng compared with 7 +/- 1 ng for normal females (P less than 0.05). Also, 6keto-PGF1 alpha excretion at 10 min was increased in diabetic subjects: males, 29 +/- 3 ng versus 19 +/- 3 (P less than 0.05); females, 33 +/- 8 versus 16 +/- 3 (P less than 0.05). The ratio of TXB2 to 6keto-PGF1 alpha tended to be higher in diabetic males.(ABSTRACT TRUNCATED AT 250 WORDS)
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118
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Foo KT, Tung KH, Tan EC, Rauff A, Tan LK, Ong YY. Genito-urinary tuberculosis--a local experience on its diagnosis and management. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 1984; 13:644-50. [PMID: 6543296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
Abstract
Though the incidence of pulmonary tuberculosis has been on the decline, the incidence of genito-urinary tuberculosis has not decreased proportionately as the majority of patients have no associated pulmonary tuberculosis. Genito-urinary tuberculosis affects male and female equally and is commonest in the 4th decade of life. The most frequent presentation is that of persistent urinary tract infection in 2/3 of patients and gross haematuria in about 1/3 of our patients. A few may be relatively asymptomatic with loin ache. Though urine culture for acid-fast bacilli is important, diagnosis in most patients was established on histopathology and typical radiological features. The main stay of treatment is medical. The role of surgery is mainly reconstructive, to overcome strictures causing obstruction so as to preserve renal function. Close cooperation between physician and surgeon is important in the management of this disease.
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119
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Jennett PA, Laxdal OE, Hayton RC, Klaassen DJ, Mainprize GW, Swanson RW, Wilson TW, Spooner HJ, Wickett RE, Tan LK. Designing education interventions to improve physician performance in office practice. MOBIUS 1984; 4:55-61. [PMID: 10269873 DOI: 10.1002/chp.4760040414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Family doctors play a very important role in determining the health of the populace; however, surveys and expert opinions indicate that there is considerable room for improvement in the knowledge and skills of family physicians concerning the prevention, early detection and management of the major causes of death and disability. Effective Continuing Medical Education (CME) could help greatly to resolve this problem. THere is, however, little evidence that presently available systems of CME, though costly, are effective in improving either physician competence or patient health. Attractive and cost-effective CME methods are greatly needed. This study develops, field tests and evaluates more efficient office-based CME programs for family doctors. Prevention, early detection and improved management of cardiovascular disease and cancer are the primary goals. A pretest posttest control group and time series approach was chosen for the experimental design. Thirty-one family physicians are participating. Physician performance and patient outcome prior to and after education are being assessed largely through office record review.
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120
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Siow BL, Tan LK. Pathological pulmonary systemic hypervascularisation--a case report. Singapore Med J 1984; 25:190-4. [PMID: 6484592] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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122
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Howe HS, Woo KT, Tan LK, Rauff A, Foong WC, Lim CH. A review of post-transplant renal artery stenosis in Singapore. Singapore Med J 1984; 25:14-7. [PMID: 6379885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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123
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Yap IL, Chua KL, Ti TK, Tan LK, Yuen R. Zollinger-Ellison syndrome--report of four cases and review of literature. ANNALS OF THE ACADEMY OF MEDICINE, SINGAPORE 1983; 12:577-83. [PMID: 6146289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Four patients with Zollinger-Ellison Syndrome (ZES) are presented to highlight the difficulties in the recognition, diagnosis and management of this rare disease. The presentation of ZES is usually indistinguishable from ordinary peptic ulcer disease and in those patients with symptoms not related to peptic ulcer, i.e., diarrhoea, as their main complaint, the diagnosis is often not even considered. A high index of suspicion is required, however, in patients with recurrent ulcers, multiple ulcers and in those with resistant or rapidly relapsing ulcers after conventional therapy. A presumptive diagnosis can be made by the demonstration of grossly elevated fasting serum gastrin levels combined with a secretin stimulation test in doubtful cases. The main problem is the location of the gastrin-secreting tumour which is usually pancreatic but often too small to be detected by currently available techniques. Histamine H2-receptor antagonists in high doses are effective in controlling the gastric acid hypersecretion which is chiefly responsible for the morbidity and mortality in ZES. They provide the treatment of choice in patients where the tumour cannot be located, though every attempt should be made to do this as surgery is the treatment of choice for this invariably malignant tumour. Total gastrectomy is now reserved for those patients in whom medical therapy has failed. The role of chemotherapy in metastatic disease has yet to be established.
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Chin WW, Godine JE, Klein DR, Chang AS, Tan LK, Habener JF. Nucleotide sequence of the cDNA encoding the precursor of the beta subunit of rat lutropin. Proc Natl Acad Sci U S A 1983; 80:4649-53. [PMID: 6192440 PMCID: PMC384101 DOI: 10.1073/pnas.80.15.4649] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
We have determined the nucleotide sequences of cDNAs encoding the precursor of the beta subunit of rat lutropin, a polypeptide hormone that regulates gonadal function, including the development of gametes and the production of steroid sex hormones. The cDNAs were prepared from poly(A)+ RNA derived from the pituitary glands of rats 4 weeks after ovariectomy and were cloned in bacterial plasmids. Bacterial colonies containing transfected plasmids were screened by hybridization with a 32P-labeled cDNA encoding the beta subunit of human chorionic gonadotropin, a protein that is related in structure to lutropin. Several recombinant plasmids were detected that by nucleotide sequence analyses contained coding sequences for the precursor of the beta subunit of lutropin. Complete determination of the nucleotide sequences of these cDNAs, as well as of cDNA reverse-transcribed from pituitary poly(A)+ RNA by using a synthetic pentadecanucleotide as a primer of RNA, provided the entire 141-codon sequence of the precursor of the beta subunit of rat lutropin. The precursor consists of a 20 amino acid leader (signal) peptide and an apoprotein of 121 amino acids. The amino acid sequence of the rat lutropin beta subunit shows similarity to the beta subunits of the ovine/bovine, porcine, and human lutropins (81, 86, and 74% of amino acids identical, respectively). Blot hybridization of pituitary RNAs separated by electrophoresis on agarose gels showed that the mRNA encoding the lutropin beta subunit consists of approximately 700 bases. The availability of cDNAs for both the alpha and beta subunits of lutropin will facilitate studies of the regulation of lutropin expression.
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Adegbite AB, Khan MI, Paine KW, Tan LK. The recurrence of intracranial meningiomas after surgical treatment. J Neurosurg 1983; 58:51-6. [PMID: 6847909 DOI: 10.3171/jns.1983.58.1.0051] [Citation(s) in RCA: 383] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
A study of 114 surgically treated patients with intracranial meningiomas was carried out to evaluate factors influencing recurrence. The data of the initial surgery extended over a 24-year period from January, 1956, to December, 1979. The patients ranged in age from 1 1/2 years to 82 years. Seventy-one (62.3%) were females and 43 (37.7%) were males. The surgical procedure was graded according to Simpson's classification from 1 to 5 (Grade 1 = complete excision, Grade 5 = simple decompression). In this series, 33 procedures (28.9%) were Grade 1, 55 (48.2%) were Grade 2, seven (6.1%) were Grade 3, 18 (15.8%) were Grade 4, and one (0.9%) was Grade 5. There were eight (7%) postoperative deaths. Approximately 60% of the tumors were located in the sphenoid wing (23.7%), convexity (21.1%), and parasagittally (14.9%). Histological diagnosis in 96% of the patients was transitional (42.1%), syncytial (34.2%), and fibroblastic (20.2%) meningiomas. Eight (7%) patients received postoperative radiotherapy. There was evidence of recurrence in 22 patients (19.3%). Twenty-one underwent a second surgical procedure. Using survival analysis, it was determined that 80% of the patients were free of recurrence 5 years after the initial surgery, and approximately 50% showed no recurrence 20 years after the initial surgery. Only the grade of the initial surgery had a statistically significant influence on recurrence. Sex of patients, site and histology of the tumor, and postoperative radiotherapy had no statistically significant influence on recurrence. Angioblastic and malignant meningiomas were rare (only four cases), and recurred relatively quickly.
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