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Biomedical subjects

J T Lin

Publications and source records attributed to J T Lin.

At least 127 records · Page 7Linked to original sources
PubMed1995

Comparison between resectable gastric adenocarcinomas seropositive and seronegative for Helicobacter pylori.

The preoperative seropositivity of Helicobacter pylori was determined in 128 patients who had undergone gastrectomy for primary gastric adenocarcinoma during the past 5 years. The overall seroprevalence of H. pylori was 64 per cent. Gastric cancers positive for H. pylori were associated with tumours located in the lower third of the stomach which were of localized type (Borrmann I and II) (P < 0.05), but not with age, sex, blood type, tumour size, invasion depth, lymph node metastases, histological type, DNA ploidy or type of surgery. The cumulative 5-year survival curves after surgical resection were significantly better in patients who were positive for H. pylori. Multivariate analysis revealed that seropositivity for H. pylori was not an independent prognostic factor. Pathological tumour node metastasis staging was the only prognostic indicator. Better prognosis for those with H. pylori-seropositive gastric cancer may be attributed to the more advanced stage of H. pylori-seronegative gastric cancers. The potential role of H. pylori in gastric cancer carcinogenesis and its biological significance warrant further investigation.

Adenocarcinoma↗
PubMed1995

Ecological study of association between Helicobacter pylori infection and gastric cancer in Taiwan.

The association between Helicobacter pylori infection and gastric cancer remains controversial. A community-based serosurvey was carried out in Taiwan to investigate the association. Serum IgG antibodies against Helicobacter pylori were examined in 728 subjects randomly selected from three townships with different gastric cancer mortality rates. The overall seropositivity of Helicobacter pylori was 54.7% (398/728) with no gender difference (males: 54.5%; females: 54.8%). The seroprevalence of Helicobacter pylori progressively increased with age in all three study townships. The age-specific seropositivity of Helicobacter pylori correlated well with age-adjusted gastric cancer mortality in the three townships. The difference in seropositivity was more profound in younger age groups. The ecological study in Taiwan suggests an association between Helicobacter pylori infection and gastric cancer. Helicobacter pylori infection in early childhood may be a key issue; in addition, a long induction time appears to be required for gastric carcinogenesis.

Adolescent↗
PubMed1995

Diagnosis of gastric adenocarcinoma using a scoring system: combined assay of serological markers of Helicobacter pylori infection, pepsinogen I and gastrin.

This study was carried out to develop a scoring system for the diagnosis of gastric adenocarcinoma (GAC). A total of 686 subjects, 150 patients with GAC, 182 with gastric ulcer, 127 with duodenal ulcer, and 227 subjects with negative findings, were enrolled. Analysis of the likelihood ratio (LR) showed that patients with advanced age, ulcer in the stomach, low serum levels of pepsinogen I (PGI), low PGI x gastrin values, and low PGI/gastrin ratio were likely to have GAC. Of these indicators, the serum PGI level had the greatest weight, with a LR of 7.59 for the group with a level < 30 ng/ml. A scoring system combining serum PGI level, Helicobacter pylori seropositivity, and gastric ulcer status was derived, using a logistic regression model. This scoring system was found to be better than any one-parameter criterion for diagnosing GAC after evaluation by the area under the receiver operating characteristic curve (0.84; 95% confidence interval, 0.81-0.88) or by specificity-fixed sensitivity (sensitivity 0.82 at specificity 0.72, sensitivity 0.87 at specificity 0.66, sensitivity 0.96 at specificity 0.44). This scoring system may be potentially useful as a new model for the noninvasive diagnosis of GAC in the future.

Adenocarcinoma↗
PubMed1995

Determinants of metastatic rate and survival in patients with Zollinger-Ellison syndrome: a prospective long-term study.

BACKGROUND/AIMS: It is unclear whether tumor location, size, or the presence of multiple endocrine neoplasia type 1 (MEN-1) alters metastatic rate and survival in patients with pancreatic endocrine tumors. The purpose of this study was to determine the prognostic factors of survival and metastatic rate in patients with Zollinger-Ellison syndrome (ZES). METHODS: Data were analyzed from 185 consecutive patients with ZES who were followed up prospectively. RESULTS: Liver metastases were present in 24% of patients and correlated with the size of the primary tumor. Duodenal tumors were smaller than pancreatic tumors. Liver metastases occurred more often (P < 0.00001) with pancreatic than duodenal tumors, whereas the metastatic rate to lymph nodes was not different. Survival of patients with liver but not lymph node metastases was shortened. In patients with sporadic ZES, liver metastases were more common during the initial evaluation and survival was decreased compared with patients with MEN-1; however, during follow-up, an equal percentage of patients with and without MEN-1 developed liver metastases. CONCLUSIONS: Survival was primarily determined by the presence of liver metastases. The frequency of liver metastases depends on the size and location of the primary tumor and on the presence of MEN-1 at the initial presentation. Metastases to the lymph nodes do not depend on these factors. A benign and malignant form of ZES exists.

Adolescent↗
PubMed1995

Bombesin does not stimulate pepsinogen release in isolated gastric chief cells.

Bombesin (BN)-related peptides, such as gastrin-releasing peptide (GRP), have been shown in vivo to stimulate release of pepsinogen. However, whether this is due to a direct interaction with chief cells is not clear. To clarify this we prepared isolated chief cells (> 90% pure) from guinea pig stomach. BN, GRP, or neuromedin B (NMB), at concentrations up to 1 microM, did not stimulate pepsinogen release or affect the stimulation caused by vasoactive intestinal peptide (VIP) (100 nM) or CCK-8 (10 nM), respectively. In addition, BN, GRP, or NMB at a concentration of 1 microM did not increase cAMP nor did they alter the increase in cAMP caused by VIP or secretin. BN (1 microM) did not alter basal cytosolic calcium [Ca2+]i or affect the increase in [Ca2+]i caused by CCK-8 (1 microM). Furthermore, BN, GRP, or NMB at a concentration of 1 microM did not increase the generation of inositol phosphates (IP) or alter the increase in [3H]IP1, [3H]IP2, or [3H]IP3, caused by CCK-8 (1 microM) or carbachol (1 mM). Binding studies demonstrated no saturable binding of either [125I][Tyr4]BN or [125I][D-Tyr0]NMB using experimental conditions where binding with other peptide ligands to other receptors on chief cells is seen. We conclude that BN-related peptides do not interact directly with specific receptors on chief cells to stimulate or alter stimulated pepsinogen secretion, increase the breakdown of inositol phosphates, or alter [Ca2+]i or cAMP.

Analysis of Variance↗
PubMed1995

Microsatellite instability in gastric carcinoma with special references to histopathology and cancer stages.

To study the molecular mechanism of gastric carcinogenesis, the frequencies of microsatellite instability were evaluated with seven dinucleotide repeat loci in 59 patients with gastric carcinoma. Microsatellite instability at two or more loci was found in 41.5% (17/41) of advanced gastric carcinoma, 21.4% (3/14) of early gastric carcinoma, but not in remnant gastric carcinoma (0/4), with an overall frequency of 33.9% (20/59). Diffuse gastric carcinoma had a similar prevalence (32.1%, 9/28) to intestinal gastric carcinoma (40.7%, 11/27). The frequency of microsatellite instability in gastric carcinoma was not significantly different with respect to age, sex and Helicobacter pylori infection. Microsatellite instability tended to occur more frequently in cancers of the cardia (62.5%, 5/8) compared with cancers of other stomach regions (31.9%, 15/47), but the difference was not statistically significant. These data suggest that microsatellite instability occurs in early gastric carcinoma and its occurrence increases during tumour progression. Furthermore, its frequency was independent of age, gender, histological types and Helicobacter pylori infection.

Adenocarcinoma↗
PubMed1995

Clinicopathologic characteristics of Helicobacter pyloric seropositive gastric adenocarcinomas.

To compare and characterize retrospectively the clinicopathologic features of gastric cancers with and without previous Helicobacter pylori infection, we determined the preoperative seropositivity of H. pylori in 151 patients who had undergone gastric resection for primary gastric adenocarcinoma between 1988 and 1993. The overall seroprevalence of H. pylori was 60.9%. H. pylori-positive gastric cancers were frequently associated (p<0.05) with macroscopic localized types (Borrmann I and II) in which negative cancer associated with infiltrative types (Borrmann III and IV) and cancer invasion of the duodenum. Multivariate analysis showed that H. pylori seropositivity was not an independent prognostic factor. Pathologic tumor-node-metastases (TNM) stage remained the only prognostic indicator. Our study suggests that H. pylori has a significant impact on the clinically relevant tumor biology of gastric cancer. Investigation along this line is warranted.

Adenocarcinoma↗
PubMed1995

Familial acanthosis nigricans with madarosis.

We report familial acanthosis nigricans affecting a 35-year-old woman, her 7-year-old son and 5-year-old daughter. Absence of the eyebrows and eyelashes was noted in this family. The mother had no axillary hair and her pubic hair was sparse. The boy also suffered from congenital heart disease and a congenital cataract in the left eye. The combination of acanthosis nigricans and ectodermal defects in this family may represent a distinct nosological entity.

Acanthosis Nigricans↗
PubMed1995

A phase II study of continuous infusion of trimetrexate in patients with refractory acute leukemia.

Trimetrexate, a second-generation folate antagonist, is a potent inhibitor of dihydrofolate reductase with a broader spectrum of activity and different mechanism of entry and intracellular accumulation than methotrexate. Six patients with refractory or relapsed acute leukemia were treated with a 5-day continuous infusion of trimetrexate of 8 mg/m2/day after an initial loading dose of 4 mg/m2 to achieve a target plasma concentration of 0.2-0.5 microM. In 4 patients with peripheral blasts at study entry, transient decrease or disappearance of blasts was observed, although no decrease of bone marrow blasts occurred. Mucositis was dose-limiting and severe in 4 patients. Neutrophil and platelet nadirs occurred on day 5-12 postinfusion. Because of dose-limiting mucositis, this dose schedule of trimetrexate is not recommended for further studies in refractory acute leukemia. However, other dose schedules (24- to 72-hr infusions) and its use as a modulating agent with thiopurines or leucovorin in patients that are resistant to methotrexate should be explored.

Adult↗
PubMed1995

Peptide structural requirements for antagonism differ between the two mammalian bombesin receptor subtypes.

Recently it has been established that both a gastrin-releasing peptide (GRP) receptor and a neuromedin B (NMB) receptor mediate the actions of bombesin-related peptides in mammals. Five different classes of peptides that function as GRP receptor antagonists have been identified; however, it is unknown whether similar strategies will yield antagonists for the closely related NMB receptor. In the present study we have used either native cells possessing only one bombesin (Bn) receptor subtype or cells stably transfected with one subtype to determine whether using the strategies that were used successfully for GRP receptors would allow NMB receptor antagonists to be identified. [DPhe12]Bn analogs; des Met14 amides, esters and alkylamides; psi 13-14 Bn pseudopeptides; and D-amino acid-substituted analogs of substance P (SP) or SP(4-11) were all synthesized and each functioned as a GRP receptor antagonist. All of these antagonists had low affinity for the NMB receptor. Application of similar strategies to NMB by formation of [DPhe8]NMB, [psi 9-10]NMB pseudopeptides, des-Met10 NMB amides, alkylamide or esters did not result in any potent NMB receptor antagonists. D-Amino acid SP and SP(4-11) analogs were weakly selective NMB receptor antagonists. No COOH-terminal fragments of NMB or GRP functioned as a GRP or NMB receptor antagonist. These results demonstrate that none of the known strategies used to prepare peptide GRP receptor antagonists are successful at the NMB receptor, suggesting that a different strategy will be needed for this peptide, such as the formation of somatostatin octapeptide or D-amino acid-substituted substance P analogs. These results suggest that even though there is a close homology between GRP and NMB and their receptors, their structure-function relations are markedly different. These results indicate that the development of receptor subtype-specific peptide agonists or peptide antagonists for newly discovered receptor subtypes of gastrointestinal hormones/neurotransmitters may be difficult because the strategies developed for one well-studied subtype may not apply to the other even though it is structurally closely related.

3T3 Cells↗
PubMed1995

A clinicopathological study of idiopathic nephrotic syndrome in children.

This paper retrospectively examines the association of outcome with histological and clinical manifestations in 107 pediatric patients with idiopathic nephrotic syndrome (INS). At the time of renal biopsy, the patients were between 2 and 15 years of age. The interval from the onset of the disease to renal biopsy ranged from 1 to 156 months with a mean of 21 months. Continuous clinical follow-up was successfully conducted in 96 patients. The average duration of INS in these patients was 86.6 months (31 to 208 months). IgM deposition in the mesangium may play an important role in the pathogenesis of INS and our data showed that even in a minor glomerular abnormality (MCNS) subgroup, nearly half of the cases (42.9%) showed mesangial IgM deposition. However, the severity of hematuria, response to drug therapy with either steroids or cyclophosphamide, and the outcome, were not related to the presence or absence of IgM deposition, but were more closely associated with the type of histological category. The subgroup of patients with focal segmental glomerulosclerosis (FSGS) and diffuse mesangial proliferation (FSGS + DP) showed the most significant ultrastructural changes with positive mesangial IgM deposition (73.6%). The presence of IgM deposition in most of the patients in the subgroups with diffuse mesangial proliferative glomerulonephritis (DPGN) and FSGS + DP closely corresponded to the presence of electron-dense mesangial deposition. The FSGS + DP subgroup had a high incidence of denudation, vacuolization and detachment of podocytes, partial collapse of the glomerular basement membrane, and a very high incidence of resistance to steroid therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Histomorphometric study in children with idiopathic nephrotic syndrome.

From 1981 to 1987, renal specimens obtained from 91 children with idiopathic nephrotic syndrome were categorized into 5 histologic subgroups, according to the WHO classification. We analyzed differences in the ratios of the size of the mesangial stalks and attached capillary, including the Bowman's space between the capillary tufts (E), mesangial matrix (Mx), and approximate capillary lumens (E-Mx) to the whole glomerular area of these subgroups using the histomorphometer-IBAS. Focal segmental glomerulosclerosis with diffuse mesangial proliferation (FSGS + DP) had the largest matrix area (Mx/G > 0.5), and smallest capillary lumen size (E/G-Mx/G) (0.3474 +/- 0.0702). On the contrary, FSGS with minimal change (FSGS + MC) had the smallest mesangial matrix (Mx/G), 0.2834 +/- 0.07726, but preserved a larger capillary lumen (0.427 +/- 0.1215). The approximate size of capillary lumens, from the smallest to the largest, was in the following order: FSGS + DP, diffuse mesangial proliferative glomerulonephritis (DPGN), focal segmental proliferative glomerulonephritis (FSPGN), FSGS + MC and minimal change nephrotic syndrome (MCNS). The ratio of the total number of mesangial cells to the area of the whole glomerulus (MCN/G) derived from the light microscopic examination was parallel to the value of Mx/G obtained by the histomorphometric technique. In summary, we introduced the histomorphometric technique using the histomorphometer-IBAS for quantitative measurement of various areas in the glomeruli. The data derived from the system is compatible with those obtained by experienced nephrologists, suggesting that the histomorphometric technique is helpful in histopathology. It is hoped that this new methodology will be used more extensively in the near future.

Adolescent↗
PubMed1995

Coverage of chest wall defect with pectoralis-breast myocutaneous flap: a report of two cases.

Reconstruction of a chest wall defect remains a challenging problem, especially where such defects are radiation related. Two cases of modified breast flaps associated with pectoralis major muscle were performed to cover a huge mediastinal defect, with heart lung exposure and a post-mastectomy radiation-related chest wall defect with partial rib resection. Both modified breast flaps healed uneventfully. No respiratory distress was encountered post-operatively. The breast flap associated with pectoralis major muscle ensured flap reliability and minimized flap complication. It is easy to raise and its size is large enough to cover of large chest wall defect which is radiation related, or those internal mammary arteries and thoracodorsal arteries compromised in previous surgery where the transverse rectus abdominis myocutaneous (TRAM) flap and latissimus dorsi flap become unreliable. In such cases a contralateral modified breast flap associated with pectoralis major muscle is the better choice.

Aged↗
PubMed1994

Transfusion-transmitted human T-cell lymphotropic virus type I infection in Taiwan: a true risk and occasional coinfection with hepatitis C virus shown in a prospective study.

To study the incidence of human T-cell lymphotropic virus (HTLV) after blood transfusion in Taiwan, serum samples from 699 patients in a prospective study were examined for seroreactivity of anti-HTLV. By an enzyme immunoassay, 9 of the 699 recipients were repeatedly positive. Serial serum samples of these 9 patients were then confirmed with a Western blot analysis and with a polymerase chain reaction (PCR) assay for HTLV-I genome. Four were already positive for anti-HTLV before transfusion, 1 carried antibodies to HTLV-I transiently after transfusion, and only 4 cases had de nova seroconversions. These patients and their family members were called back and tested for HTLV-I genome in the peripheral blood mononuclear cell (PBMC) and plasma. All the serologically positive patients, except the "transient one," were positive for HTLV sequences in the PBMCs. Viral sequences could also be detected in several serum or plasma samples. In the family members, only the spouse of a pretransfusion-positive patient was infected. These results suggested that approximately 0.6% of the blood recipients were infected by HTLV-I through transfusion in Taiwan, and that the frequency of intrafamilial HTLV-I transmission is low. We also observed the unusual coinfection by both HTLV-I and hepatitis C virus in 2 patients, and superinfection of hepatitis C virus after blood transfusion in 1 HTLV-I carrier. Cases of coinfection suggest a prevalence of both viruses in blood donors and warrant further screening.

Adolescent↗
PubMed1994

Phalloplasty for female transsexuals with sensate free forearm flap.

One of the primary goals of phalloplasty on female to male transsexuals is to void while standing. However, achieving competence of the neourethra, sensation, and rigidity of the neophallus still present a challenge. Over a 5 year period (1988-1993), 56 phalloplasties using sensate free forearm flaps were performed for 56 primary female transsexuals. The urethrocutaneous fistula rate was 38/56 and one flap totally necrosed. However, when the flap was prefabricated with a tubed graft of vaginal mucosa for the 28 cases (the later part of the series), there were less complications and a lower fistula rate within this portion of the neourethra. Although the whole procedure was time consuming, it was worthwhile and patient satisfaction was high.

Female↗