Biomedical subjects

J S Lin

Publications and source records attributed to J S Lin.

At least 109 records · Page 6Linked to original sources

PubMed1996

Multispectral magnetic resonance images segmentation using fuzzy Hopfield neural network.

This paper demonstrates a fuzzy Hopfield neural network for segmenting multispectral MR brain images. The proposed approach is a new unsupervised 2-D Hopfield neural network based upon the fuzzy clustering technique. Its implementation consists of the combination of 2-D Hopfield neural network and fuzzy c-means clustering algorithm in order to make parallel implementation for segmenting multispectral MR brain images feasible. For generating feasible results, a fuzzy c-means clustering strategy is included in the Hopfield neural network to eliminate the need for finding weighting factors in the energy function which is formulated and based on a basic concept commonly used in pattern classification, called the 'within-class scatter matrix' principle. The suggested fuzzy c-means clustering strategy has also been proven to be convergent and to allow the network to learn more effectively than the conventional Hopfield neural network. The experimental results show that a near optimal solution can be obtained using the fuzzy Hopfield neural network based on the within-class scatter matrix.

Algorithms↗

PubMed1996

Implications of urinary basic fibroblast growth factor excretion in patients with urothelial carcinoma.

1. Angiogenesis occurs in response to wounding, and is of vital importance for tumour growth and metastasis. Basic fibroblast growth factor, a well-known angiogenic factor, has been suggested to be a urine marker for urothelial carcinoma. However, the relevance of its detection has not been evaluated in a large number of patients. 2. Immunoassay of basic fibroblast growth factor was performed on urine samples from different aetiologies of urothelial disorder. Expression of basic fibroblast growth factor in the corresponding tumour was correlated with the urine level. 3. The excretion of basic fibroblast growth factor (ng/g creatinine) was significantly elevated in both inflammatory and neoplastic urological diseases compared with normal individuals (P < 0.05), while it was normalized in tumour-free subjects (P < 0.01). Receiver operating characteristic plotting revealed a sensitivity of 40% for tumour diagnosis at the cut-off point of 3.29 ng/g creatinine. The sensitivity of the test in predicting tumour recurrence was only 14%. The basic fibroblast growth factor level in urine showed a positive association with increasing age of cancer patients (P = 0.02) and with tumour grading (P = 0.05). However, no important relationship was observed regarding tumour stage, size, number, shape or degree of local inflammatory reaction (P > 0.01). Pairwise analysis of the basic fibroblast growth factor level in urine and its expression in corresponding tumours did not reveal a conspicuous correlation (r = -0.097, P = 0.43). 4. Our results suggested that estimation of urinary basic fibroblast growth factor cannot be satisfactory as a tumour marker. The measurement may represent one of the tissue responses to injury or the host-tumour interactions. A longitudinal study is required to elucidate the role of basic fibroblast growth factor in order to select the appropriate treatment strategy for urothelial carcinoma.

Adult↗

PubMed1996

Transfusion of donor peripheral blood buffy coat cells as effective treatment for relapsed acute leukemia after transplantation of allogeneic bone marrow or peripheral blood stem cells from the same donor.

BACKGROUND: The transfusion of same-donor peripheral blood buffy coat (PBBC) cells to chronic myelocytic leukemia patients in relapse after bone marrow transplantation has been increasingly used as an effective antileukemic therapy. A graft-versus-leukemia effect mediated by immunocompetent donor T cells underlies its success. In acute leukemia, however, the effect of this adoptive cellular immunotherapy has not been established, and the results are generally poor. STUDY DESIGN AND METHODS: Five patients, three with acute lymphoblastic leukemia and two with acute myelocytic leukemia, who relapsed within 6 months after allogeneic marrow transplantation were enrolled in a nonrandomized pilot study to receive donor PBBC cell transfusions either before or after undergoing cytoreductive chemotherapy. ABO genotyping and polymerase chain reaction amplification of human tetrameric short tandem repeats DNA typing were used to test for marrow chimerism. RESULTS: Two acute lymphoblastic leukemia patients-both of whom underwent chemotherapy before PBBC cell transfusions, experienced a complete remission, and developed acute and then chronic, extensive graft-versus-host disease-have been leukemia-free for 9 and 7 months, respectively. Repeated molecular studies of their marrow as early as 2 weeks to 8 months after treatment confirmed that the marrow was of donor origin. The other three patients, who chose not to undergo chemotherapy before PBBC cell transfusions, failed to achieve remission and died 14, 16, and 30 days, respectively, after leukemia relapse. CONCLUSION: Adoptive cellular immunotherapy may be effective for acute lymphoblastic leukemia patients in relapse after bone marrow transplantation if chemotherapy is administered before PBBC cell transfusions are initiated.

Acute Disease↗

PubMed1996

Prognostic factors of primary transitional cell carcinoma of the upper urinary tract.

OBJECTIVES: We presented and analyzed our results in order to determine the relationship between patient survival and tumor grade and/or stage. In addition, a retrospective tumor DNA ploidy study was done to evaluate its possible role in predicting future tumor recurrence in the bladder. METHODS: A total of 112 patients with upper urinary tract transitional cell carcinomas (TCCs) were recorded at our hospital. Of these, 68 patients without concurrent bladder tumors (ages ranged from 36 to 80, mean 62.4 years; male:female = 1:1.2) were treated by nephroureterectomy and bladder cuff resection. They were followed up for 14-79 months (average 38.2 months). Eight (36.4%) of the 22 patients who had stage C or D tumors had received adjuvant systemic methotrexate, vinblastine, epirubicin, cisplatin chemotherapy after surgery. DNA flow cytometry using paraffin-blocked tumor specimens was performed on the tumors of 52 patients. RESULTS: Their pathologic stages and grades were 11 at stage 0, 15 at stage A, 20 at stage B, 14 at stage C, 8 at stage D; 9 of grade I, 41 of grade II, and 18 of grade III. Postoperatively, 13 patients (19.1%) subsequently developed bladder tumors with a latent period ranging from 2 to 37 months (average 14.9 months). The difference of the tumor DNA ploidy distribution pattern among tumors of high versus low stages and/or grades is not statistically significant (p > 0.05). Overall, the 5-year survival rates for patients with low- and high-stage tumors were 100 and 66.7%, respectively; for patients with grade I-II and III tumors they were 93.6 and 28.3%, respectively. CONCLUSIONS: Patient survival was mainly related to both tumor stages (p = 0.0037) and grades (p = 0.0001), rather than to tumor DNA ploidy. For patients with grade II upper urinary tract tumors, tumor DNA ploidy seems to provide no additional predictive value on subsequent tumor recurrence in the bladder.

Adult↗

PubMed1996

The half-moon sign. A useful roentgen sign of saccular aneurysm of the aortic arch.

OBJECTIVE: The half-moon sign is defined as a shadow seen on the lateral chest radiograph consisting of a smooth, partially demarcated opacity with the rounded portion of the half moon projecting over the aortic lumen at the level of the aortic arch, but the rest of the opacity merging with the aorta. In this study, we intended to evaluate the clinical usefulness of half-moon sign in aiding a diagnosis of saccular aneurysm of the aortic arch. METHODS: This series consisted of 57 patients with aortic arch aneurysm and 46 patients with a variety of nonvascular intrathoracic masses that presented as soft-tissue masses adjacent to the aortic arch on the frontal chest radiographs. The half-moon sign was evaluated independently by two senior chest radiologists who had no knowledge of the final causes. RESULTS: The half-moon sign was shown on the lateral chest radiographs in 5 of 10 patients with saccular aortic arch aneurysm but absent in 47 patients with fusiform aortic arch aneurysm. Furthermore, this roentgen sign was not seen on the lateral chest radiographs in 46 patients with nonvascular intrathoracic masses. In this selected population, the sensitivity and specificity of the half-moon sign in aiding a diagnosis of saccular aneurysm of the aortic arch were 50% and 100%, respectively. CONCLUSION: The half-moon sign shown on the lateral chest radiograph is highly suggestive of the saccular aortic arch aneurysm.

Adult↗

PubMed1996

Type I collagen and procollagen fragments in patients with metabolic bone diseases.

The purpose of the present study was to evaluate the serum levels of two new markers, and to compare their clinical usefulness with two conventional markers. Healthy women and patients with aberrant bone metabolism were evaluated for serum or urine levels of different bone markers. We measured serum levels of the pyridinoline cross-linked telopeptide domain of type I collagen (S-ICTP) and carboxy-terminal propeptide of type I procollagen (S-PICP) as markers of bone resorption and formation, respectively. These levels were compared to the concentrations of serum bone gamma-carboxyglutamic acid protein (S-BGP) and total urinary pyridinium cross-links (U-PYD). The control group included 222 premenopausal and postmenopausal women, and the disease groups consisted of 61 individuals with malignancy-associated hypercalcemia, Graves' thyrotoxicosis or primary hyperparathyroidism. Both S-PICP and S-BGP reflected higher bone turnover in postmenopausal than premenopausal women. All patient groups had significantly higher S-ICTP and U-PYD than the controls. Increased S-PICP was seen in malignancy-associated hypercalcemia and Graves' thyrotoxicosis, but not in primary hyperparathyroidism, while higher S-BGP was seen in Graves' thyrotoxicosis and primary hyperparathyroidism, but not in malignancy-associated hypercalcemia. Discrepancy between S-PICP and S-BGP in malignancy-associated hypercalcemia and primary hyperparathyroidism was noted. S-ICTP and U-PYD had higher sensitivity and specificity in discriminating patients from controls. We conclude that S-ICTP is superior to U-PYD as an index of bone resorption in aberrant bone metabolism. S-PICP may also be a useful bone turnover marker but discrepancies between it and S-BGP in malignancy-associated hypercalcemia and primary hyperparathyroidism need further investigation.

Adult↗

PubMed1995

Incidence of internal cancers and ingested inorganic arsenic: a seven-year follow-up study in Taiwan.

In order to elucidate the dose-response relationship between ingested inorganic arsenic and internal cancers, a total of 263 patients with blackfoot disease and 2293 healthy residents in the endemic area of arseniasis were recruited and followed up for 7 years. The information on consumption of high-arsenic artesian well water, sociodemographic characteristics, life-style and dietary habits, and personal and family history of cancers was obtained through standardized interviews. The occurrence of internal cancers among study subjects was determined through annual health examinations, home visit personal interviews, household registration data checks, and national death certification and cancer registry profile linkages. A dose-response relationship was observed between the long-term arsenic exposure from drinking artesian well water and the incidence of lung cancer, bladder cancer, and cancers of all sites combined after adjustment for age, sex, and cigarette smoking through Cox's proportional hazards regression analysis. Blackfoot disease patients had a significantly increased cancer incidence after adjustment for cumulative arsenic exposure.

Arsenic↗

PubMed1995

Selective suppression of type B monoamine oxidase immunoreactivity in the raphe nuclei following MPTP administration in the cat.

Using immunohistochemistry, we investigated in the cat the effects of MPTP, a Parkinsonian syndrome-inducing substance, on brain type B monoamine oxidase (MAO-B) which is responsible for the conversion of MPTP to its neurotoxic product (MPP+). Intraperitoneal administration of MPTP (5 mg kg-1 daily for 5 days) caused a selective suppression of MAO-B in neurones of the raphe nuclei without affecting hypothalamic MAO-B. Since these effects were accompanied by loss of nigral dopaminergic cells but not of raphe cell bodies or 5-HT immunoreactivity, we suggest that MPTP suppresses raphe MAO-B without destroying its presumed host serotoninergic neurones and that raphe MAO-B does not appear to be crucial in the MPTP-induced nigral lesion. In addition, the MPTP-induced paradoxical sleep suppression might be related to this raphe MAO-B loss.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1995

Effects of whole blood flow rates on mononuclear cell yields during peripheral blood stem cell collection using Fenwal CS 3000 Plus.

It is generally assumed that using high whole blood flow rates (WBFR), 80 ml/min, during peripheral blood stem cell (PBSC) collection on the Fenwal CS 3000 Plus blood cell processor will result in higher yields of mononuclear cells (MNC) than using lower WBFR (50 ml/min). To test this assumption, we retrospectively studied 129 PBSC procedures on 17 patients in a multiple myeloma protocol comparing MNC yield, as well as red blood cell (RBC), granulocyte, and platelet (Plt) content, of four average WBFR groups. Standard PBSC procedures were performed using modified procedure 1, interface offset 100, anticoagulant (AC) ratio of 11:1, small volume collection chamber, and a processing time of 4 hours. After correcting for AC volume used, the volume processed was divided by 240 minutes to obtain the average WBFR. WBFRs were separated into 4 groups of 40-49, 50-59, 60-69, and 70-79 ml/min. When compared to the highest flow rate group (70-79 ml/min), the three lower flow rate groups had significantly higher MNC yields of 16.2 +/- 6.9, 13.1 +/- 5.1, and 11.5 +/- 4.7 x 10(9), respectively, as compared to 8.9 +/- 6.1 x 10(9) MNC for the 70-79 ml/min group. There was no significant difference in granulocyte yield which ranged from 1.6 +/- 2.1 to 4.5 +/- 4.8 x 10(9).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

Differentiation between nodules and end-on vessels using a convolution neural network architecture.

In recent years, many computer-aided diagnosis schemes have been proposed to assist radiologists in detecting lung nodules. The research efforts have been aimed at increasing the sensitivity while decreasing the false-positive detections on digital chest radiographs. Among the problems of reducing the number of false positives, the differentiation between nodules and end-on vessels is one of the most challenging tasks performed by computer. Most investigators have used a conventional two-stage pattern recognition approach, ie, feature extraction followed by feature classification. The performance of this approach depends totally on good feature definition in the feature extraction stage. Unfortunately, suitable feature definition and corresponding extraction implementation algorithms proved to be very difficult to define and specify. A convolution neural network (CNN) architecture, trained by direct connection to the raw image is proposed to tackle the problem. The CNN, which uses locally responsive activation function, is directly and locally connected to the raw image. The performance of the CNN is evaluated in comparison to an expert radiologist. We used the receiver operating characteristics (ROC) method with area under the curve (Az) as the performance index to evaluate all the simulation results. The CNN showed superior performance (Az = 0.99) to the radiologist's (Az = 0.83). The CNN approach can potentially be applied to other applications, such as the differentiation of film defects and microcalcifications in mammography, in which the image features are difficult to define or not known a priori.

Algorithms↗

PubMed1995

Use of the urine-to-blood carbon dioxide tension gradient as a measurement of impaired distal tubular hydrogen ion secretion among neonates.

To evaluate the utility of the urinary-minus-blood partial pressure of carbon dioxide (U-B PCO2) gradient for the diagnosis of distal renal tubular acidosis in neonates, we measured the U-B PCO2 gradient corresponding to different urinary bicarbonate concentrations in 40 neonates. The U-B PCO2 gradient in these neonates had a significant linear relationship to the urinary bicarbonate concentration. When the urinary bicarbonate concentration was > 10 mmol/L, in all the neonates the U-B PCO2 could be increased above the 20 mm Hg level. We conclude that it is appropriate to determine the U-B PCO2 gradient as an index of distal urinary acidification and that it is a necessary test for diagnosis of distal renal tubular acidosis in neonates.

Acidosis, Renal Tubular↗

PubMed1995

Clinical significance of urinary ferritin excretion in patients with transitional cell carcinoma.

1. The serum ferritin level provides a valuable index of the body iron store. An increase in serum ferritin has often been observed in patients with neoplastic disease and correlates well with the stage of cancer. A few studies have suggested the potential of urinary ferritin as a marker for transitional cell carcinoma. The rationale of the measurement, however, has not been investigated in detail. 2. Urinary ferritin levels were evaluated in patients with diverse urological diseases to investigate their potential clinical implications. 3. Analysis of logarithmic transformed values (ng/mg creatinine) showed that patients with both neoplastic and non-neoplastic urological diseases had significantly higher ferritin levels than normal control subjects (P = 0.02). There was no apparent difference between subgroups of patients with urological disease (P > 0.5). For patients with urothelial carcinoma, univariate analysis revealed a strong positive relationship between urinary ferritin levels and the density of lymphoid cells in tumour stroma (P = 0.0001), while no important association was observed with tumour grade (P = 0.32), stage (P = 0.29) or urinary cytology detection (P = 0.33). Patients with muscle-invasive tumour had significantly higher ferritin levels than those with papillary, superficial cancer (P < 0.05). For patients with non-neoplastic urological disease (n = 19), urinary ferritin levels tend to correlate with the severity of tissue inflammation (P = 0.03). 4. The results suggest that urinary ferritin may reflect the degree of local inflammatory reaction in the urinary tract.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1995

The inflammatory cytokine response to Chlamydia trachomatis infection is endotoxin mediated.

Chlamydia trachomatis is a major etiologic agent of sexually transmitted diseases. Although C. trachomatis is a gram-negative pathogen, chlamydial infections are not generally thought of as endotoxin-mediated diseases. A molecular characterization of the acute immune response to chlamydia, especially with regard to the role of its lipopolysaccharide (LPS), remains to be undertaken. We extracted 15 mg of LPS from 5 x 10(12) C. trachomatis elementary bodies (EB) for analysis of structure and biological activity. When methylated lipid A was subjected to high-pressure liquid chromatography followed by mass spectrometry, the majority of the lipid A was found to be pentaacyl. The endotoxin activities of whole C. trachomatis EB and purified LPS were characterized in comparison with whole Salmonella minnesota R595 and with S. minnesota R595 LPS and lipooligosaccharide from Neisseria gonorrhoeae. Both C. trachomatis LPS and whole EB induced the release of tumor necrosis factor alpha from whole blood ex vivo, and C. trachomatis LPS was capable of inducing the translocation of nuclear factor kappa B in a Chinese hamster ovary fibroblast cell line transfected with the LPS receptor CD14. In both assays, however, C. trachomatis was approximately 100-fold less potent than S. minnesota and N. gonorrhoeae. The observation that C. trachomatis is a weak inducer of the inflammatory cytokine response correlates with the clinical observation that, unlike N. gonorrhoeae infection, genital tract infection with C. trachomatis is often asymptomatic. The ability of specific LPS antagonists to completely inhibit the tumor necrosis factor alpha-inducing activity of whole C. trachomatis EB suggests that the inflammatory cytokine response to chlamydia infection may be mediated primarily through LPS. This implies that the role of other surface protein antigens, at least in terms of eliciting the proinflammatory cytokine response, is likely to be minor.

Antigens, CD↗

PubMed1995

Effects of pregnancy and progesterone on autonomic function in the rat urinary bladder.

Previous studies have shown that pregnancy is associated with a decrease in cholinergic function in the rabbit urinary bladder. The present study aimed at evaluating the effects of pregnancy on the autonomic function of the rat urinary bladder and to elucidate whether progesterone is responsible for such alterations. Female Wistar rats, 3 months old, were divided into four groups: (1) 2-week pregnant rats; (2) rats given daily intramuscular injections of progesterone 5 mg/kg for 2 weeks; (3) rats given intramuscular injections of vehicle for 2 weeks, and (4) controls. Cystometry showed a significant increase in bladder capacity in the pregnant rats. The wet weight of the pregnant rat bladder was also significantly increased. Histologic study revealed increased bladder wall thickness with interstitial edema and urothelium proliferative changes to a papillary configuration in these pregnant bladders. Bladder muscle strip study showed significantly reduced maximum contractile responses to acetylcholine and methoxamine in the pregnant and the progesterone groups. Muscarinic receptor binding study demonstrated reduced Bmax in the pregnant rats and rats receiving progesterone injections (control group Bmax = 57 +/- 11, pregnant group Bmax = 44 +/- 8, p < 0.05; progesterone group Bmax = 40 +/- 7, vehicle group Bmax = 58 +/- 9 fmol/mg protein, p < 0.05). The contractile response to lower concentrations (10(-6) mol/l to 10(-4) mol/l) of ATP was elevated in the pregnant rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1995

Correlation of transrectal ultrasonographic findings of the prostate with the occurrence of detrusor instability in patients with benign prostatic hyperplasia.

Forty patients with benign prostatic hyperplasia were evaluated with urodynamics and transrectal ultrasonography. Seventeen patients were found to have detrusor instability while the remaining 23 did not. No significant differences were noted during ultrasonography in the estimated prostatic volume, the presumed circle area ratio and the incidence of finding prostatic calcification between these two groups. However, the incidence of detecting intravesical protrusion of the prostate is significantly higher in patients with instability than in patients with stable bladder (53 vs. 13%, p < 0.01). It is therefore postulated that intravesical protrusion may increase afferent impulses from the prostate and alter the stability status of the urinary bladder.

Aged↗

PubMed1995

Role of cyclic adenosine monophosphate in prostaglandin E1-induced penile erection in rabbits.

To investigate the role of cyclic adenosine monophosphate (cAMP) in penile erection in relation to the effect of prostaglandin E1 (PGE1) male adult New Zealand white rabbits were utilized as a model to study intracavernous pressure (ICP) in vivo. After intracavernous injection of PGE1 (0.2-1.6 micrograms/kg) and 8-bromocyclic adenosine monophosphate (8-Br-cAMP, 0.5-1.5 mg/kg), both drugs raised the ICP in a dose-dependent manner. The increased ICPs induced by PGE1 and 8-Br-cAMP were 33.4 +/- 8.12 and 24.1 +/- 4.9 mm Hg, respectively (p < 0.05, paired Student's t test). Administrations of cyclic adenosine monophosphothioate, Rp-isomer (cAMP antagonist, 0.02-0.08 mumol/kg) prior to PGE1 injections inhibited the effect of PGE1 in vivo in a dose-dependent manner. The systemic blood pressures and heart rates in rabbits were unchanged during all the intracavernous injections. The corpus cavernosal tissues isolated from rabbits were studied for the cAMP contents after incubation of different doses of PGE1 in vitro. The cAMP contents were also elevated in a manner parallel with the increases in PGE1 concentrations (3-9 microM). We conclude: (1) the feasibility of intracavernous injection of vasoactive drugs is similar to that in man, thus the rabbit can be used as a suitable alternative for the studies of penile erection, and (2) cAMP is mediated in PGE1-induced relaxation of the rabbit corpus cavernosum, and the cAMP system only participates partially in penile erection.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed1995

The role of transrectal ultrasonography on the palpable and impalpable abnormal prostate.

Two hundred and three male patients underwent transrectal ultrasonography (TRUS) examination because of palpable nodule or hard consistency of the prostate. Of these, 56 of 65 (86.2%) digital rectal examination (DRE)-abnormal and 34 of 138 (24.6%) DRE-normal patients received transrectal sonoguided core needle biopsy. Among the DRE-abnormal patients, 18 (32.1%) had prostatic adenocarcinoma by biopsy with 2 additional patients who had initial negative biopsies eventually found to have cancer by transurethral resection of the prostate. In contrast, only 2 (5.9%) of 34 DRE-normal patients had cancers that were both hypoechoic and peripheral zone located. In 13 patients with transitional zone located lesions (hypoechoic 9, isoechoic 4), none had cancer. Of 27 patients who had normal DRE and unsuspected TRUS and received transurethral prostatectomy because of bladder outlet obstruction, 4 (14.8%) had cancer. In this study, hypoechoic lesions were found in 68 patients, among them 60 (88.2%) underwent biopsy but only 14 (23.3%) had cancer. From the results of this study, we concluded that TRUS can be a useful adjunct of DRE in detecting prostatic malignancy, especially when there has been an abnormal DRE, but its role on a digitally normal prostate requires further evaluation. Serum prostate-specific antigen can be an additional indicator to increase the prostate cancer detection rate.

Adenocarcinoma↗

PubMed1995

Detubularized folded O-shaped ileal bladder.

Using a submucosal needle tunneling technique for ureteral implantation, detubularized folded O-shaped ileal bladders were created for seven patients in need of bladder replacement. A segment of ileum of only 300 to 400 mm in length was required. Anastomosis of the reservoir to the urethra was simply performed by tailoring the ileum to reduce tension at the anastomosis site. Follow-up periods ranged from 24 to 46 months. Excellent upper tract function and good evacuation function with minimal residual urine were demonstrated. Urodynamic studies revealed a mean bladder capacity of 367 mL, with low intra-ileobladder pressure. All patients are continent during the day. Mild enuresis was noted in three patients. No reflux was noted on follow-up voiding cystourethrography. This type of ileal bladder is simple to create and provides reliable results. The presence of a short mesentery is not a serious limiting factor.

Adult↗