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Biomedical subjects

J C Lin

Publications and source records attributed to J C Lin.

At least 217 records · Page 12Linked to original sources
PubMed1990

Characterization of four newly established human colorectal adenocarcinoma cell lines from Chinese patients.

Four colon adenocarcinoma cell lines, CC-M2, CC-M3, CC-M4, and CC-M2NM, have been established from surgical specimens of 18 unselected patients without the use of "feeder" cells and additional growth factors (e.g., insulin, hydrocortisone, etc.) in the culture medium. The methods of primary cultivation of tissue explants are described. Studies of determination of morphology, growth curve, plating efficiency, chromosomal analysis, CEA and beta-HCG synthesis, and tumorigenicity, were done to characterize the cell lines. Significant variations have been found in one of the four cell lines, both in vitro and in vivo studies. There are distinct phenotypes in the established cell lines which may be useful in studying the cell differentiation and progression of colorectal cancer.

Adenocarcinoma↗
PubMed1990

Extralobar pulmonary sequestration of the left retroperitoneum.

This paper presents an extralobar pulmonary sequestration in the left retroperitoneum in an eight year old girl. The clinical and diagnostic features included abdominal pain, an abdominal mass, elevated VMA, and radiological manifestations simulating a left adrenal mass. A laparatomy was performed. Extralobar pulmonary sequestration of the left retroperitoneum is fairly uncommon. An eight year old girl was admitted with abdominal pain, elevated urinary VMA and an abdominal mass. The radiological manifestations simulated a left adrenal mass. At surgery an extralobar pulmonary sequestration was detected.

Bronchopulmonary Sequestration↗
PubMed1990

Cancer of the auricle.

Thirty-five patients with carcinoma of the auricle seen in Veterans General Hospitals, Taipei and Taichung from January 1970 to December 1988 were reviewed retrospectively. There were 28 men and 7 women. More cases occurred in the 7th and 8th decades with an average of 64 years (median 67) and ranged from 29 to 91 years. The most common manifestations at diagnosis were exophytic mass (86%) and/or ulcerative lesion (29%). Histologically, basal cell carcinoma outnumbered squamous cell carcinoma 17 to 14. The remaining 4 cases consisted of 2 melanomas, 1 sweat gland adenocarcinoma and 1 unclassified sarcoma. Eighty-eight percent (15/17) of basal cell carcinoma presented at early stage without regional lymph node or distant metastasis. They were mainly treated by surgery. One patient with multifocal lesions suffered from marginal recurrence. The 2 and 5-year survival rates were 94% and 86% respectively. Half of our 14 patients with squamous cell carcinoma had local extensive tumor but no lymph node or distant metastasis was found at the time of diagnosis. Local recurrence occurred in 4 patients, one case associated with lung metastasis. The local control rate of combined surgery and irradiation in squamous cell carcinoma was 100% (4/4), superior than that of operation alone 67% (6/9) or radiotherapy alone (0/1). The actual 2 and 5-year survival rates were 85% and 64% respectively. Our 4 patients with different pathology other than basal cell or squamous cell carcinoma had high rate of regional lymph nodes or distant metastases, presenting poor prognosis. The overall treatment failure for carcinoma of the auricle was 23% (8/35) but reduced to 14% after salvage treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Perianal Paget's disease--report of 4 cases.

Over the past nine years (from 1981 to 1989), four patients with perianal Paget's disease were treated. All were male with an average age of 58.5 years. Clinically, perianal Paget's disease manifests as a slowly enlarging eczematous, and sharply demarcated perianal skin rash that may be oozing or itching. In the characteristic pathology finding, Paget's cells appear as large, rounded signet-ring cells with abundant mucin stain positive cytoplasm in the basal layer of the acanthotic epidermis. All but one, who suffered from primary sweat gland carcinoma, had underlying rectal adenocarcinoma. The first two cases expired soon after a delayed diagnosis of terminal underlying malignancy. Only in the later two cases was there a preoperative suspicion of perianal Paget's disease. There is often a delay in diagnosis due to clinical ignorance. Patients with persisting perianal skin rash should be biopsied frequently. If perianal Paget's disease is diagnosed, the underlying malignancy should be surveyed and managed thoroughly.

Aged↗
PubMed1990

Effects of hydralazine on the blood flow in RIF-1 tumors and normal tissues of mice.

Hydralazine is a peripheral vasodilator used as an antihypertensive agent. Hydralazine has been reported to potentiate tumor damage by hyperthermia as well as by hypoxic-cell-specific drugs through the reduction of tumor blood flow and pO2. In the present study, we investigated the changes in blood perfusion caused by hydralazine in S.C. RIF-1 tumors and normal tissues in C3H mice using the 86Rb uptake technique and laser Doppler flowmetry. The tumor blood flow was decreased significantly by an intravenous administration of 0.5-10.0 mg/kg hydralazine, as determined by both uptake of 86Rb and laser Doppler flowmetry. The tumor pO2 was also decreased significantly by the injection of hydralazine. On the other hand, the uptake of 86Rb was increased significantly in the skin and muscle by hydralazine. The changes seen in the skin and muscle after injection of hydralazine as assessed by laser Doppler flowmetry were similar to those assessed by uptake of 86Rb, indicating a significant increase in blood circulation in these tissues. Uptake of 86Rb remained unchanged in the kidney and decreased in the liver and spleen in the presence of hydralazine in a dose-dependent manner at 0.5-10.0 mg/kg. The decline in uptake of 86Rb in normal tissues strongly suggests that hydralazine decreases the blood flow in these normal tissues. Thus the recent proposal to use hydralazine to increase the antitumor activity of heat or certain drugs needs to be reexamined.

Animals↗
PubMed1989

The kinetics of vascular thermotolerance in SCK tumors of A/J mice.

Development of thermotolerance has been observed in diverse biological systems. Despite the important role of blood circulation in heat-induced tissue damage, little is known about vascular thermotolerance. The kinetics of vascular thermotolerance in SCK tumors of A/J mice was investigated in this study. A single heating at 43.5 degrees C or 44.5 degrees C for 1 hr caused marked damage in tumor vasculature, as demonstrated by a marked decrease in Rb-86 uptake (% of injected dose/g of dried tissue). The tumor vasculature became resistant or tolerant to subsequent heatings at those temperatures when the tumors were preheated at 42.5 degrees C for 1 hr. Vascular thermotolerance became significant at 5 hr and reached its maximum at 18 hr after preheating at 42.5 degrees C. When the vascular thermotolerance was at its peak, heating at temperatures as high as 44.5 degrees C for 1 hr could not reduce the tumor blood flow. The vascular thermotolerance decayed considerably but not completely at 72 hr after the preheating. The vascular thermotolerance may exert a profound implication on the response of tissues, including tumors, to multiple heatings.

Adaptation, Physiological↗
PubMed1989

Synergistic inhibition of Epstein-Barr virus: transformation of B lymphocytes by alpha and gamma interferon and by 3'-azido-3'-deoxythymidine.

We analyzed the effects of 3'-azido-3'deoxythymidine (AZT) and alpha and gamma interferon (IFN-alpha and IFN-gamma) on transformation of human umbilical cord lymphocytes (HUCLs) by Epstein-Barr virus (EBV). B lymphocytic outgrowth from HUCLs infected with EBV was monitored by focus formation; the presence of EBV genomes in transformed foci was confirmed by in situ cytohybridization and EBV nuclear antigen. The 50% inhibitory doses for preventing focus formation were 0.14 microM for AZT, 10 units (U)/mL for IFN-alpha, and 1 U/mL for IFN-gamma. To determine whether inhibition resulted from direct cytotoxic effects, we assessed the viability of nontransformed HUCLs exposed to the agents for 30 d. The nontoxic doses were 1 microM for AZT, 30 U/mL for IFN-alpha, and 3 U/mL for IFN-gamma. Combining IFN-alpha or IFN-gamma with AZT or IFN-alpha with IFN-gamma at nontoxic doses showed synergistic decreases in numbers of transformed foci. Transformation of HUCLs by EBV was sensitive to, but not abolished by, these agents at doses below those required for cell killing.

B-Lymphocytes↗
PubMed1989

Reversal by glucose of pancreatic amylase insufficiency in chronic alcoholic rats.

Carbohydrate consumption regulates pancreatic amylase synthesis in rats. The Lieber-DeCarli 36% alcohol diet employed in chronic alcohol studies and the isocaloric control diet contain 11 and 47% of total calories from carbohydrates, respectively. Young rats fed ad libitum the 36% ethanol diet for 2 weeks obtained 1.2 g/day of carbohydrate, whereas those pair-fed with control diet received 5.8 g/day. Rats fed the 36% ethanol diet and given an intramuscular injection of a solution of 1.5 g of glucose daily for 2 weeks received twofold greater amounts of carbohydrate than saline-injected controls (2.7 versus 1.2 g). These changes in carbohydrate intake produced proportionate changes in pancreatic amylase levels. The secretory responses to cholecystokinin-octapeptide (CCK8) of acini from control and glucose-injected rats were significantly higher compared with those in the saline-injected or noninjected alcohol groups. The blood alcohol levels in glucose-injected rats were markedly reduced compared with other alcohol groups (71.7 versus 274.9 mg/dl) despite similar amounts of ethanol ingestion daily (2.4 g) in the three groups. In vitro experiments with acini from rats fed a nutritionally optimal diet revealed that high pharmacologic concentrations of ethanol, while inducing basal secretion, inhibited CCK8-stimulated amylase secretion. These results indicate that: (a) the amount of alcohol consumption does not correlate with either the levels of blood alcohol or of pancreatic amylase; (b) the carbohydrate availability in rats regulates pancreatic amylase levels despite significant levels of alcohol in blood; (c) blood alcohol levels observed in vivo may not affect synthetic and secretory processes of amylase in pancreatic acini.

Alcoholism↗
PubMed1989

Regulation of pancreatic amylase by dietary carbohydrate in chronic alcoholic rats.

The nutritional adequacy of dietary ingredients is essential for optimal food consumption and growth of animals. Dietary carbohydrate levels regulate pancreatic amylase synthesis. Ethanol diets with 36% of total calories from ethanol and 11% from carbohydrate are nutritionally inadequate, whereas a 26% ethanol diet made isocaloric to the 36% alcohol diet by the addition of maltose-dextrins provides all nutrients in amounts recommended for normal growth. Young rats fed the modified ethanol diet for 3 months consume 101.4 ml of diet daily compared to 66.5 ml by those on the 36% ethanol diet. Increased food consumption results in (a) similar amounts of alcohol consumption (3.6 vs. 3.3 g/day), (b) a threefold enhancement in carbohydrate intake (5.1 vs. 1.7 g/day), and (c) a normal growth rate (6.7 vs. 3.1 g/day). Both the acinar content of amylase (20.2 +/- 0.3 micrograms/mg of protein) and the acinar response to cholecystokinin-octapeptide in 36% ethanol diet-fed rats are significantly reduced compared to those of 26% ethanol diet-fed rats (34.1 +/- 5.6 micrograms/mg of protein). These results confirm (a) the nutritional adequacy of the 26% ethanol diet compared to the 36% ethanol diet, and (b) that carbohydrate inadequacy, and not ethanol consumption per se, is the primary cause of pancreatic amylase insufficiency in chronic alcoholic rats.

Alcoholism↗
PubMed1989

Monoclonal antibody against rat renal cell tumor-associated antigen as a new tool for the analysis of renal tumorigenesis.

A monoclonal antibody, NR-2 MAb, against one of the rat renal cell tumor-associated antigens was developed. NR-2 MAb belonged to IgM class and recognized a polypeptide of 81,000 daltons designated as NR-2 antigen, which is of non-glycoprotein nature with a pI of 4.6. NR-2 MAb was employed to probe the histogenesis of renal cell tumors in rats treated with N-ethyl-N-hydroxyethylnitrosamine followed by trisodium nitrilotriacetate monohydrate. Immunohistochemical analysis indicated that NR-2 antigen was expressed in simple hyperplasia, adenomatous hyperplasia and renal cell tumors. Both clear cells and basophilic cells of the simple hyperplasia showed equally strong positive reactions with NR-2 MAb, whereas the vacuolated epithelium was negative. Furthermore, the proximal tubules in nontumorous areas also expressed NR-2 antigen, suggesting that the hyperplastic lesions which eventually lead to renal cell tumors may derive from epithelia of proximal tubules and not directly from vacuolated epithelium. Such NR-2 antigen-positive epithelia of proximal tubules seem to be initiated cells. NR-2 MAb also cross-reacted with preneoplastic liver lesions.

Animals↗
PubMed1989

The Epstein-Barr virus (EBV) BZLF1 immediate-early gene product differentially affects latent versus productive EBV promoters.

The Epstein-Barr virus (EBV) BZLF1 gene product is thought to mediate the disruption of latent EBV infection. We have examined the regulatory effects of BZLF1 by studying its transactivating effects on seven different EBV promoters. We find that whereas the BZLF1 gene product increases the activity of the two early promoters, BMLF1 and BMRF1, it decreases the activity of three latent promoters (the BamHI-C and BamHI-W Epstein-Barr nuclear antigen promoters and the latent membrane protein promoter). The BZLF1-induced changes in promoter-directed chloramphenicol acetyltransferase activity occur in EBV-negative as well as EBV-positive cell lines and are accompanied by a similar change in chloramphenicol acetyltransferase mRNA. Deletion analysis of the BamHI Z fragment indicates that in a portion of the amino-terminal half of the BZLF1 gene product (amino acids 24 to 86) is not essential for positive transactivating effects but is required for down-regulating effects. Thus, different domains of the same EBV immediate-early gene product can either increase the function of EBV promoters active in productive infection or decrease the function of key promoters active in latent infection.

Cell Line↗
PubMed1989

The Epstein-Barr virus immediate-early gene product, BMLF1, acts in trans by a posttranscriptional mechanism which is reporter gene dependent.

In DNA cotransfection experiments, the Epstein-Barr virus immediate-early gene product, BMLF1, stimulated the chloramphenicol acetyltransferase (CAT) activity of both latent and productive EBV promoters linked to CAT. This BMLF1-induced increase in CAT activity was out of proportion to the effect on CAT mRNA, suggesting a posttranscriptional mechanism. Furthermore, when growth hormone was used as a reporter gene instead of CAT, BMLF1 no longer functioned. Thus, the BMLF1 effect was reporter-gene dependent. The effect of the BMLF1 gene product does not then appear to be directed at promoter activation, but instead may function to increase the level of an as yet unidentified protein(s) required for Epstein-Barr virus infection.

Chloramphenicol O-Acetyltransferase↗
PubMed1989

[Sensory action potentials of ring finger in the diagnosis of carpal tunnel syndrome].

Amplitudes and latencies of sensory action potentials (SAPs) recorded over the index, middle, little and ring fingers by antidromic stimulation of the median or ulnar nerve at wrist were measured in 65 normal adults and 78 patients with clinically and electrophysiologically verified carpal tunnel syndrome. In the normal adults, there was no significant difference among the SAP latencies of the index, middle, ring and little fingers. Among these 65 normal adults, the difference between median and ulnar SAPs of ring finger was less than 0.4 msec in 64 subjects, but 0.7 msec in one. In the patient group, the median distal sensory latency of the ring finger was significantly longer than that of the ulnar nerve which was recorded over the ring and little fingers. Six cases (7.7%) of 78 patients diagnosed as CTS by conventional electrophysiological studies was false negative by using the ring finger sensory action potential study. It is suggested that the SAP study of the ring finger by stimulation of the median and ulnar nerves at the wrist can not replace the conventional electrodiagnostic methods for the diagnosis of carpal tunnel syndrome.

Action Potentials↗
PubMed1988

Structural determinants for transcriptional activation by cAMP-responsive DNA elements.

A transcriptional cAMP-responsive enhancer element (CRE) consisting of the 8-base pair (bp) palindrome, 5' TGACGTCA 3', is found in several eukaryotic genes. We analyzed the effects on gene transcription of point mutations within the CRE, the influence of the bases surrounding the CRE, and the requirements for transcriptional synergism of tandemly repeated CREs. When inserted as an oligonucleotide with restriction enzyme linker sites, the 8-bp CRE itself is as active in conferring cAMP responsivity on an enhancerless chloramphenicol acetyltransferase reporter plasmid as is a single copy of the choriogonadotropin alpha (CG alpha), twice repeated 18-bp sequence containing the CRE. Point mutations in the first (T to A), fourth (C to G), or eighth (A to T) positions of the CRE, when contained within the CG alpha 18-bp sequence, each inhibited transcriptional activity greater than 90%. However, the identical eighth position A to T mutation occurs in the cAMP-responsive sequence of the vasoactive intestinal peptide (VIP) gene, and that mutant sequence in the context of the adjacent bases of the native VIP sequence is maximally cAMP responsive when inserted in the reporter plasmid. The substantially reduced activity of the core 8-bp CRE when synthesized as a cassette including the adjacent bases of the rat glucagon or bovine parathyroid hormone gene further emphasizes the restrictive influence of particular surrounding sequences. Active oligonucleotides containing the 8-bp palindrome and different but equally permissive contexts have comparable properties in transfected reporter genes and gel mobility-shift assays. The pair of tandemly repeated 18-bp elements containing the CRE in the CG alpha gene synergistically stimulate transcription either with paired native CREs or when one native CRE is paired with one mutant CRE, suggesting the presence of cooperative interactions. Tandem insertion of more than two 18-bp sequences, or insertion of additional sequences between the two CREs, inhibits transcription. These observations indicate that the contexts of the bases adjacent to CREs exert profound influences on the transcriptional activities mediated by the cAMP-responsive elements.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1988

Microwave-induced thermoelastic pressure wave propagation in the cat brain.

This paper presents direct measurements of acoustic pressure wave propagation in cat brains irradiated with pulsed 2.45-GHz microwaves. Short rectangular microwave pulses (2 microseconds, 15 kW peak power) were applied singly through a direct-contact applicator located at the occipital pole of a cat's head. Acoustic pressure waves were detected by using a small hydrophone transducer, which was inserted stereotaxically into the brain of an anesthetized animal through a matrix of holes drilled on the skull. The measurements clearly indicate that pulsed microwaves induce acoustic pressure waves which propagate with an acoustic wave velocity of 1523 m/s.

Acoustics↗
PubMed1988

Cavernous hemangioma of the thoracic spinal cord.

A 25-year-old woman presented with a four-year history of progressive right-lower-extremity weakness and atrophy and a left hemisensory deficit was found. Metrizamide-enhanced spinal CT scan showed an intramedullary lesion at the level of T1-T2; this had expanded the cord in fusiform fashion but showed no evidence of a cystic component. Surgical resection was performed and the pathological diagnosis was cavernous hemangioma. Two and one-half years later, her left hemisensory deficit was worsening and a spinal MRI showed high signal intensity mass in the region of the previous surgery consistent with chronic hematoma which was re-evacuated with some improvement in the patient's neurological condition.

Adult↗
PubMed1988

What is expected of CT in the evaluation of stroke?

This study was based on 5042 cranial CT examinations in a 2-year period. 19.8% of all cranial CT scans were performed for confirmation or evaluation of clinically suspected stroke. 87% of the clinical diagnoses of stroke were confirmed by CT scan. Intracranial hemorrhage made up a small percentage in this study. The establishment of this diagnosis was a valuable service in the patients' management. Brain tumor may rarely present clinical symptoms mimicking stroke and may have a normal CT initially.

Cerebral Hemorrhage↗