Biomedical subjects

J C Lin

Publications and source records attributed to J C Lin.

At least 163 records · Page 9Linked to original sources

PubMed1994

Concomitant chemoradiotherapy for advanced epidermoid carcinoma of the uterine cervix: a preliminary report.

BACKGROUND: Because the prognosis of advanced carcinoma of the uterine cervix is poor, and has improved very little in the last 20 years, a prospective study was initiated to evaluate the feasibility, response and toxicities of concomitant chemoradiotherapy for such cervical cancer. METHODS: From May 1992 to December 1992, 22 patients entered the study, 21 of them completed the entire treatment. Their ages ranged from 47 to 72 years, median 57. There were 16 FIGO stage IIIB, and 5 stage IIB. Radiotherapy was administered using 1.8 Gy/day, five days a week, to the whole pelvis (50.4 Gy/28 fractions) with or without parametrial boost according to the tumor response. Intracavitary brachytherapy 5 Gy x five to six times was given after one or two weeks of rest. Chemotherapy consisted of etoposide 100 mg/m2 day 1 + cisplatin 50 mg/m2 day 1 + bleomycin 25 mg/m2/day day 2-3, repeated every two weeks during external irradiation. RESULTS: All 21 eligible patients achieved complete response, sustaining during a median follow-up time of 12 months. All the initially elevated tumor markers (SCC, CEA, CA-125) returned to normal range after treatment. The toxicity was well tolerated. CONCLUSIONS: Concomitant chemoradiotherapy for advanced cervical carcinoma is both feasible and effective, with acceptable toxicities. Long-term follow-up is mandatory, and a randomized trial to confirm the superiority of this protocol will be started soon.

Adult↗

PubMed1994

MR imaging evaluation of bone marrow signal change in post-irradiation patients with nasopharyngeal carcinoma.

BACKGROUND: The normal distribution of red and yellow marrow can be altered by therapeutic irradiation, which causes a well-documented sequence of bone marrow changes. This study measured the T1 signal intensity of the clivus and cervical vertebral bodies of NPC patients who had received a complete course of radiation therapy. METHODS: There were 3 categories of patients: Group I: NPC patients who had radiation myelitis; 14 persons which a total 20 times of MRI. Group II: NPC patients, without radiation myelitis; 6 patients, which a total 6 times of MRI. Group III (control group): patients who received MRI of the cervical spine because of cervical spondylosis or HIVD, were total of 45 patients. In the sagittal section of T1WI, the signal intensity of the bone marrow of clivus and C2 to T1 vertebral bodies was measured. RESULTS: 1). There were homogeneous increases of signal intensity of the bone marrow of clivus and C2 to T1 in Groups I and II. 2). There was no statistical difference between Groups I and II. 3). The increased signal intensity of bone marrow after radiation showed no difference in short and long duration between radiation therapy and MR examinations, indicating that bone marrow signal intensities were increased in NPC patients whether or not they had radiation myelitis. CONCLUSIONS: Signal change in bone marrow may have occurred soon after radiation therapy, and may have persisted for several years. The radiation myelitis always involved the low medulla oblongata to C5 level; however, the bone marrow signal change always extended downward to the T1 level, so bone marrow is more sensitive than the spinal cord and is prone to be affected by irradiation.

Adult↗

PubMed1994

Endogenous Candida endophthalmitis: a case report.

We experienced a 63-year-old male with a typical finding of endogenous Candida endophthalmitis. Candida albicans was cultured from the vitreous tapping. The patient received oral fluconazole treatment and the symptom improved. In this report, the clinical manifestations of endogenous Candida endophthalmitis and the experience of fluconazole treatment were reported.

Candidiasis↗

PubMed1994

Pain on injection of propofol.

A controlled randomized double-blinded clinical study was undertaken to evaluate and compare the efficacy of three methods of preventing pain during injection of propofol on induction of anesthesia. Patients were randomly allocated to six groups: saline pretreatment, followed by induction with propofol at room temperature plus saline; lidocaine pretreatment, followed by induction with propofol at room temperature plus saline; saline pretreatment, followed by induction with propofol at a temperature of 4 degrees C plus saline; lidocaine pretreatment, followed by induction with propofol at a temperature of 4 degrees C plus saline; saline pretreatment, followed by induction with propofol at room temperature plus lidocaine 40 mg; saline pretreatment, followed by induction with propofol at a temperature of 4 degrees C plus lidocaine 40 mg. Pretreatment with lidocaine reduced the incidence of pain and discomfort significantly compared with unpretreated groups. Groups which received propofol mixed with lidocaine also showed a significant reduced incidence of pain. induction with cold 4 degrees C propofol showed no significant difference in reduction of injection pain.

Adult↗

PubMed1994

Mycobacterium smegmatis keratitis after radial keratotomy--a case report.

A 42-year-old woman who developed a corneal ulcer in the left eye after radial keratotomy. The acid-fast stain showed that numerous clusters of acid-fast bacilli and Mycobacterium smegmatis were isolated on the culture. To the best of our knowledge, this is the first documented case of Mycobacterium smegmatis keratitis in the world literature. The sensitivity test showed that this organism resistant to all the anti-tuberculous agents and antibiotics we test. An initial response to amikacin and kanamycin was found, but relapse of infiltrate was noted one month later. The regimen was therefore changed to a combination of amikacin with ofloxacin. This patient had a favorable response to the topical therapy with amikacin and ofloxacin.

Adult↗

PubMed1994

Concomitant chemoradiotherapy for advanced head and neck cancer.

Head and neck cancer is mostly curable in the early stages by either surgery or radiotherapy alone, but the control rate for advanced stages is low, even with combined surgery and postoperative radiotherapy. From September, 1990, to January, 1992, 35 patients with locoregionally advanced head and neck cancers were entered in a prospective study of concomitant chemoradiotherapy. Thirty-three completed the treatment. There were 29 males and four females with a median age of 53 years. All except one patient were in stage IV. Radiotherapy was delivered using a telecobalt unit and by conventional fractionation (1.8 Gy/fraction, 5 fractions/wk). Chemotherapy with cisplatin (10 mg/m2/day, daily, days 1-5) and 5-FU (500 mg/m2/day continuously infused for five days) was given concurrently during the first and fifth weeks of radiation. Twenty-four among 31 eligible patients achieved complete response (77.4%) and the other seven (22.6%) partial response, resulting in a 100% response rate. The toxicities experienced were increased compared with those caused by radiotherapy alone. The most common side effects were gastrointestinal and hematologic toxicities but the whole treatment was well tolerated. The two-year actuarial survival rate is 45%. We found the primary origin and overall treatment time to affect survival significantly. The survival rate for tumors arising from the nasopharynx or paranasal sinus is better than for those arising from other regions of the head and neck. The shorter treatment times (within eight weeks) had a better survival rate. Our preliminary experience suggests that concomitant chemoradiotherapy is both feasible and effective for head and neck cancer. The optimal scheduling and dosage of concomitant chemoradiotherapy should be further researched.

Adolescent↗

PubMed1994

Experience of anesthesia for transthoracic endoscopic sympathectomy in palmar hyperhidrosis--110 cases.

Transthoracic endoscopic sympathectomy (TES) is an effective treatment for palmar hyperhidrosis. We review our experience and discuss the anesthetic technique and perioperative complications encountered in 110 patients undergoing TES for palmar hyperhidrosis. All patients were monitored with EKG, NIBP and pulse oximetry (SPO2) during the operation. The trachea was intubated with a single lumen endotracheal tube and ventilation was controlled manually. 100% inspired oxygen was necessary during TES to avoid hypoxia. One patient developed sudden cardiac arrest during electrocauterization of the left sympathetic chain and two patients required underwater drainage for hemothorax. Minimal pneumothorax was diagnosed in 4 patients and all cases resolved spontaneously without active treatment.

Adolescent↗

PubMed1993

Establishment of estrogen receptor-positive transplantable rat thyroid tumor cell lines in vivo.

We established 17 transplantable rat thyroid tumor cell lines from the primary thyroid tumor of rats induced by N-bis(2-hydroxypropyl)nitrosamine. Among the 17 tumor cell lines established, only two of them (D1 and G1) were estrogen receptor (ER) positive. These two cell lines were characterized with respect to transplantability, histological features, ER contents and cellular localization, and expression of ER message. The ER contents, determined by dextran-coated charcoal assay, were 13.3 and 20.7 fmol/mg protein for D1 and G1 cell lines, respectively. Scatchard plot analysis indicates that the dissociation constants (Kd) were 0.17 and 0.4 nM, respectively, for D1 and G1 cell lines. Sucrose density centrifugation analysis detected a hormone-receptor complex which sedimented at the 4S region, characteristic for ER. Immunohistological staining revealed that the ER was localized in the nuclei. The presence of ER in D1 and G1 cell lines was further confirmed by reverse transcriptase-polymerase chain reaction to detect the ER mRNA. These results demonstrated that ER is expressed in some thyroid tumors. The ER-positive transplantable tumor cell lines are useful for studying the direct effect of estrogen on thyroid tumors in vitro and in vivo.

Animals↗

PubMed1993

The Epstein-Barr virus DNA polymerase transactivates the human immunodeficiency virus type 1 5' long terminal repeat.

We have demonstrated in transient expression assays that the Epstein-Barr virus (EBV) DNA polymerase transactivates expression of the bacterial chloramphenicol acetyltransferase (CAT) gene linked to the human immunodeficiency virus (HIV) type 1 5' long terminal repeat (LTR). The evidence was provided by two sets of experiments. Transfection of Raji cells with HIV LTR-CAT followed by superinfection with EBV resulted in a 150-fold increase in CAT activity. In the presence of viral DNA inhibitor 3'-azido-3'-deoxythymidine (AZT), the CAT activity was inhibited by approximately 70%, suggesting that EBV DNA polymerase was involved in the transactivation of HIV LTR. The direct proof came from the cotransfection of HIV LTR-CAT with expression plasmid containing EBV polymerase gene; depending on the polymerase gene construct cotransfection with both plasmids resulted in a 23- to 38-fold increase of HIV LTR-CAT activity. The interaction between EBV polymerase and HIV may contribute to the role of EBV as a cofactor in the pathogenesis of AIDS.

Binding, Competitive↗

PubMed1993

Precision of genotyping of Epstein-Barr virus by polymerase chain reaction using three gene loci (EBNA-2, EBNA-3C, and EBER): predominance of type A virus associated with Hodgkin's disease.

To precisely determine the genotype of Epstein-Barr virus (EBV) in Hodgkin's disease (HD), we simultaneously analyzed three divergent gene loci (EBNA-2, EBNA-3C, and EBER) that distinguish type A and B viruses. The primers designed to amplify these three gene loci encompass either type-specific deletion sequences (EBNA-2 and EBNA-3C) or type-specific point mutations (EBER) that identify the virus strain based on the sizes of the polymerase chain reaction (PCR)-amplified products or the mobility shifts in single-strand conformation polymorphism analysis. The locations of point mutations were identified by direct sequencing of the PCR-amplified DNA. We analyzed 15 EBV-infected cell lines and found a good correlation between EBNA-2 and EBNA-3C typing results. In contrast, approximately 33% of the cell lines analyzed maintained type A sequences in EBNA-2 and EBNA-3C genes while carrying type B sequences in the EBER region. Data obtained from analysis of cell lines served as a reference for studying HD samples. EBV DNA was detected in about 70% of HD. Among the EBV-positive samples, 56% were associated with type A virus, 13% with type B, and 31% with dual viral sequences. Thus, type A virus is predominant in HD. Based on the histology, the frequencies of EBV positivity were 83%, 71%, and 33% for mixed cellularity, nodular sclerosis, and lymphocyte predominance, respectively. The detection of high frequency of both type A and B sequences in HD may provide a lead in investigating the role of dual viral infection in EBV pathogenesis.

Antigens, Viral↗

PubMed1993

Influence of vascular thermotolerance on the heat-induced changes in blood flow, pO2, and cell survival in tumors.

Vascular thermotolerance in SCK tumors of A/J mice was studied by comparing the changes in blood flow, as measured by the 86Rb uptake method, from a single heating with those from two heatings. The heat-induced decline in 86Rb uptake in tumors could be substantially inhibited when the tumors were preheated, indicating the development of vascular thermotolerance. In SCK tumors, the vascular thermotolerance peaked 5 or 18 h after the tumors were heated for 1 h at 41.5 degrees C or 42.5 degrees C, respectively. Consequently, the tumor blood flow decreased by 50% in 81 min when the tumors were heated at 43.5 degrees C without preheating, whereas the tumor blood flow decreased by 50% in 195 min at 43.5 degrees C when the tumors were preheated 18 h earlier at 42.5 degrees C for 1 h. The influence of vascular thermotolerance on the heat-induced changes in intratumor pO2 was also investigated. The average intratumor pO2 was 8.9 mm Hg before heating. Heating at 43.5 degrees C or 44.5 degrees C for 1 h dramatically decreased the intratumor pO2 to 3.0 or 1.2 mm Hg, respectively. However, the intratumor pO2 decreased to 6.6 or 3.8 mm Hg when the tumors were heated at 43.5 degrees C or 44.5 degrees C, respectively, 18 h after preheating at 42.5 degrees C for 1 h. Heating the tumors when tumor vasculatures were at peak thermotolerance was relatively ineffective in suppressing tumor growth. The data demonstrate that vascular thermotolerance in tumors may exert profound effects on tumor response to multiple heatings in clinical hyperthermia.

Animals↗

PubMed1993

Cranial computed tomography in children with acute lymphoblastic leukemia after prophylactic treatment with cranial radiation therapy and intrathecal methotrexate.

BACKGROUND AND METHODS: Thirty-one children with acute lymphoblastic leukemia (ALL) who had received cranial radiation therapy (CrRT) and five concomitant doses of intrathecal methotrexate (IT MTX) for central nervous system prophylaxis (CNSP) and who had an event-free survival exceeding 5 years had cranial computed tomography (Cr CT) examination. The fractional dose for 21 of them was 1.5 Gy. The interval between the completion of CNSP and the time of Cr CT ranged from 5 to 8.5 years, with a median of 5 years 2 months. RESULTS: Unlike the previous reports in the literature that 9-77% of children with ALL who had received Cr RT 18 Gy and IT MTX as CNSP had CT scan abnormalities, in this study no patient had CT scan abnormalities. CONCLUSIONS: Our results might be attributable to the fractional dose of Cr RT being adequate, the IT chemotherapy being suitable, and the systemic chemotherapy not being intensive.

Brain↗

PubMed1993

Optimalization of southwestern technique for detection of binding of Epstein-Barr virus nuclear antigen 1 to origin of replication.

An optimized protocol of Southwestern analysis for detection of Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1) binding to the origin of viral replication (oriP) was described. The unique feature of this optimized protocol includes the restoration of the denatured proteins to native conformation after SDS-polyacrylamide gel electrophoresis and blocking of nonspecific and low-affinity binding sites prior to DNA binding. The parameters and conditions that may affect the specific interaction of EBNA-1 to oriP DNA were then determined. The specific binding was affected by divalent cations (MgCl2) and ionic strength; the optimal concentrations of MgCl2 and NaCl were observed at 10 and 300 mM, respectively. The various buffer systems and pH values tested had no apparent effect on EBNA-1 binding. Under the optimal conditions, a single protein of 68 Kd was detected and the bindings of other nonspecific, low-affinity DNA-binding proteins were abolished. The authenticity and specificity of 68 Kd protein as EBNA-1 were determined by reaction with antibody specific for EBNA-1 and competition assay with specific DNA sequence. After optimization this technique can be a powerful and yet simple means of studying protein-DNA interactions and their roles in gene expression.

Antigens, Viral↗

PubMed1993

Antitumor effect of interleukin 1 alpha in combination with hyperthermia.

The combined effects of interleukin-1 alpha (IL-1 alpha) and hyperthermia on SCK tumors grown in the legs of A/J mice were investigated. When the host mice were given i.p. injections of 25 micrograms/kg IL-1 alpha, the tumor blood perfusion, as measured with the 86Rb uptake method, significantly declined, reaching minimum blood perfusion in 3-5 h. Although the tumor blood perfusion started to rise thereafter, the recovery was still incomplete 1 day later. Hyperthermia at 42.5 degrees C or 43.5 degrees C for 1 h also caused a marked decline in tumor blood perfusion. When the tumors were heated 5 h after an i.p. injection of IL-1 alpha at 25 micrograms/kg, at which time the tumor blood perfusion was low, the tumor blood perfusion decreased further. The heating of tumors at 42.5 degrees C or 43 degrees C for 1 h significantly reduced the clonogenic cell number in the tumors, delayed the tumor growth, and prolonged the survival time of host animals. The antitumor effect of 25 micrograms/kg IL-1 alpha alone, as judged from the clonogenic cell number, tumor growth delay, and host survival, was smaller than that of hyperthermia. When the host mice were treated with IL-1 alpha and the tumors were heated 5 h later, the decline in the clonogenic tumor cell number, tumor growth delay, and prolongation of host survival were significantly greater than those produced by either treatment alone. It was concluded that the prior reduction of blood perfusion by IL-1 alpha potentiated the antitumor effect of subsequent heatings.

Animals↗

PubMed1993

Recurrent ascending myelitis: an unusual presentation of herpes simplex virus type 1 infection.

We report on a healthy female with a unique relapsing transverse myelitis accompanied by herpes simplex virus type 1 (HSV-1) infection. Magnetic resonance imaging showed cord enlargement and increased signal intensity on T1-weighted image with gadolinium enhancement from T-4 to T-10 during the first attack and from C-1 to C-2 during the second episode. She was not diagnosed during the first attack. During the second episode, laboratory studies disclosed IgM and IgG antibodies to HSV at the outset with greater than fourfold increases in antibody levels in the serum and cerebrospinal fluid (CSF). Cells cultured from the CSF were positive for HSV-1 according to the immunofluorescence method. The presence of HVS-1 DNA in CSF was documented by polymerase chain reaction (PCR) technique. Acyclovir was given with a partial recovery. We anticipate that PCR assay of CSF will assist early diagnosis of herpetic central nervous system disorders.

Aged↗

PubMed1993

The effect of pulsed microwaves on passive electrical properties and interspike intervals of snail neurons.

The effects of pulsed microwaves (2.45 GHz, 10 microseconds, 100 pps, SAR: 81.5 kW/kg peak, 81.5 W/kg average) on membrane input resistance and action potential (AP) interval statistics were studied in spontaneously active ganglion neurons of land snails (Helix aspersa), at strictly constant temperature (20.8 +/- .07 degrees C worst case). Statistical comparison with sham-irradiated neurons revealed a significant increase in the mean input resistance of neurons exposed to pulsed microwaves (P < or = .05). Pulsed microwaves had no visible effect on mean AP firing rate; this observation was confirmed by analysis of interspike intervals (ISIs). Using an integrator model for spontaneously active neurons, we found the net input current to be more variable in neurons exposed to pulsed microwaves. The mean input current was not affected. The standard deviation of ISIs and the autocorrelation of the input current were marginally affected, but these changes were not consistent across neurons. Although the observed effects were less obvious than those reported in other studies, they represent evidence of a direct interaction between neurons and pulsed microwaves, in the absence of macroscopic temperature changes. The data do not suggest a single, specific mechanism for such interaction.

Animals↗

PubMed1993

Neurofibroma: an unusual presentation.

We report neurofibroma discovered incidentally in a woman who suffered trauma to her cheek. The lesion was manifest on CT as a haematoma within a parotid tumour.

Adult↗

PubMed1993

Computed tomography of spontaneous intracranial haemorrhage due to haemostatic disorders in children.

Intracranial haemorrhage is a serious problem in haemostatic disorders in children. Intracranial bleeding is sometimes more marked than suspected clinically. Computed tomography (CT) permits accurate, sensitive diagnosis of intracranial haemorrhage. We report 13 patients; 3 patients with hypoprothrombinaemia, 4 patients with thrombocytopenia or platelet dysfunction and 6 with haemophilia A, B or Von-Willebrand's disease. One patient with hypoprothrombinaemia had a subarachnoid hemorrhage (SAH), one a subdural haematoma (SDH) and the third a combination of SAH, SDH and intracerebral haematoma (ICH). One patient with thrombocytopenia or platelet dysfunction had a SDH, while the others had ICH. In the six patients with haemophilia A, B or Von-Willebrand's disease, there were four examples of ICH, five of SAH and six of SDH. A neurosurgical procedure was performed in only one patient. Three children died of serious intracranial complications with uncal herniation.

Adolescent↗