PubMed Health⌕ Search

Biomedical subjects

D Han

Publications and source records attributed to D Han.

At least 55 records · Page 3Linked to original sources
PubMed1997

[The study of effects of immunologic modifier on proliferation and cytotoxicity against HEP-2 of LAK cells in vitro].

Adoptive immunotherapy as a new approach has been used to treat advanced carcinoma for almost ten years, and gained some good results. However, the application of this method is largely restricted by the side effects along with high dose of IL-2 and lack of sufficient amount of LAK cells. Mycobacterial Polysaccharides (MPS) and anti-CD3 antibodies (CD3Ab) have been demonstrated to be effective immunologic modifiers capable of proliferating lymphocytes and increasing cytotoxity against tumor cells. In this article we discussed the effects of MPS and CD3Ab on proliferation and cytotoxity against HEP-2 cells of LAK cells. Our results showed that: 1. MPS group (incubating IL-2 2 x 10(5)/L plus MPS 0.4 mg/L) or CD3 group (IL-2 1 x 10(6)/L plus CD3Ab 4 mg/L) were more proliferative than LAK group (only incubated with IL-2 1 x 10(6)/L). MPS group is the most proliferative in the three groups, P < 0.05. 2. Cytotoxity against HEP-2 in MPS or CD3 group was also better than in LAK group. CD3 group could maintain good cytotoxity in the longest period. These results could provide guidance for adoptive immunotherapy assisted by MPS or CD3Ab.

Antibodies, Monoclonal↗
PubMed1997

[The observation on treatment effects of local adoptive immunotherapy in 33 cases with head and neck cancer].

OBJECTIVE: To evaluate treatment effects of local adoptive immunotherapy in 33 cases with head and neck cancer. METHODS: IL-2 1 x 10(5)-2 x 10(5) U per day was injected into tumor for 10 days; during the 4th-8th day LAK cells 1.0 x 10(8)-5.0 x 10(8) per day were combined with IL-2 injection. Then we analysized clinical effect, immunopathology, side effects, etc. RESULTS: CR was seen in 1 case; PR in 6, MR in 20 cases, and SD in 6 cases. The one-, two- and three-year survival rate was 96.3%, 83.3% or 75.0% respectively. The results of histopathology showed that there were large amount of T lymphocytes (CD3+/4+) infiltrating in the tumor area after immunotherapy. No serious side effects were found during the course of the treatment. CONCLUSION: Local injection of IL-2/LAK can be used as immunotherapy for head and neck cancer.

Adolescent↗
PubMed1996

Temporal specificity of muscarinic synaptic modulation of the Ca(2+)-dependent K+ current (ISAHP) in rat hippocampal neurones.

1. We examined synaptic modulation of the Ca(2+)-dependent K+ current (ISAHP), which underlies the slow after-hyperpolarization (sAHP) in hippocampal CA1 neurones of rat brain slices. ISAHP was evoked in whole-cell voltage-clamp mode by depolarizing pulses, and synaptic afferents to CA1 neurones were stimulated electrically with a paired-pulse protocol. 2. Afferent stimulation delivered 200-1500 ms prior to be depolarizing pulse produced a profound reduction of ISAHP by 58%, but not other Ca(2+)-dependent outward currents that preceded ISAHP. Perfusion of slices with atropine significantly attenuated the synaptic reduction of ISAHP, indicating an event mediated largely by muscarinic receptor activation. When delivered < 400 ms after the depolarizing pulse, similar synaptic stimuli produced no substantial reduction in ISAHP, even in neurons where the duration of ISAHP was prolonged to 8-10 s either by lowering the recording temperature or by intracellular application of a calcium chelator. 3. To examine the effect of cholinergic stimulation of the depolarization-activated Ca2+ influx, high-threshold voltage-activated Ca2+ currents were recorded in the conventional or perforated whole-cell mode. Perfusion of slices with 5-10 microM carbachol for 5-10 min caused no substantial decrease in these Ca2+ currents, suggesting that the synaptic reduction of ISAHP is unlikely to be due to a blockade of depolarization-induced Ca2+ influx which triggers the generation of ISAHP. 4. The present data demonstrate that afferent stimulation reduces ISAHP only if it occurs prior to the depolarization-induced Ca2+ influx. We propose that modulation of inactive sAHP channels by muscarinic stimulation may decrease their sensitivity to the influx of Ca2+, whereas sAHP channels activated by Ca2+ may compete with the receptor-coupled modulation thus rendering the sAHP channels unresponsive to cholinergic afferent stimulation.

Animals↗
PubMed1996

Evolution of proneural atonal expression during distinct regulatory phases in the developing Drosophila eye.

BACKGROUND: Receptors of the Notch family affect the determination of many cell types. In the Drosophila eye, Notch antagonises the basic helix-loop-helix (bHLH) protein atonal, which is required for R8 photoreceptor determination. Similar antagonism between Notch and proneural bHLH proteins regulates most neural cell determination, however, it is uncertain whether the mechanisms are similar in all cases. Here, we have analyzed the sensitivity of atonal expression to Notch signalling using a temperature-sensitive Notch allele, by the expression of activated Notch or of the ligand Serrate, and by monitoring expression of the atonal-dependant gene scabrous and of the Notch-dependent Enhancer of split genes. RESULTS: The atonal expression pattern evolves from general "prepattern' expression, through transient "intermediate groups' to R8 precursor-specific expression. Successive phases of atonal expression differ in sensitivity to Notch. Prepattern expression of atonal is not inhibited. Inhibition begins at the intermediate group stage, corresponding to the period when atonal gene function is required for its own expression. At the transition to R8 cell-specific expression, Notch is activated in all intermediate group cells except the R8 cell precursor. R8 cells remain sensitive to inhibition in columns 0 and 1, but become less sensitive thereafter; non-R8 cells do not require Notch activity to keep atonal expression inactive. Thus, Notch signaling is coupled to atonal repression for only part of the atonal expression pattern. Accordingly, the Enhancer-of-split m delta protein is expressed reciprocally to atonal at the intermediate group and early R8 stages, but is expressed in other patterns before and after. CONCLUSIONS: In eye development, inhibition by Notch activity is restricted to specific phases of proneural gene expression, beginning when prepattern decays and is replaced by autoregulation. We suggest that Notch signalling inhibits atonal autoregulation, but not expression by other mechanisms, and that a transition from prepattern to autoregulation is necessary for patterning neural cell determination. Distinct neural tissues might differ in their proneural prepatterns, but use Notch in a similar mechanism.

Animals↗
PubMed1996

IL2 triggers a tumor progression process in a melanoma cell line MELP derived from a patient whose metastasis increased in size during IL2/INFalpha biotherapy.

Human melanomas may express both in vivo and in vitro functional IL-Rs and may be expected to directly respond to injected IL2. This may generate biological situations which may be favourable for the patient, but also for tumor progression. Here, we analyse the latter hypothesis. MELP is a melanoma cell line derived from a patient whose metastasis increased in size during IL2/IFN alpha biotherapy [correction of biotheraphy]. These cells have been characterized in vitro for their phenotype and for their sensitivity to IL2. In vitro MELP cells express an IL2-R alpha(+) beta(+) gamma(-) phenotype and IL2 treatment induces the acquisition of new functional characteristics represented (i) by the increased surface expression of two markers of metastatic evolution (ICAM-1 and CD44); (ii) by the stable induction of the IL2-R gamma with the appearance of functional IL2-R beta complex, which are also recognized by GM-CSF; (iii) by the inhibition of transcription of a regulatory cytokine such as IL6; (iv) by a differential effect of IL6 on CD44 surface expression in MELP cells treated or not with IL2 (MILG cells); (v) by the acquisition of faster growth rates and appearance of piling up and multilayer cellular organization; (vi) by the development of rapidly growing tumors in nude mice. IL2 induces in MELP cells a tumor progression process that could mimic the metastatic evolution observed in vivo during biotherapy. Therefore, MELP phenotype may help to define a subset of patients in which IL2 therapy may trigger unfavourable evolution.

Adult↗
PubMed1996

Single-tube nested polymerase chain reaction assay based on Flagellin gene sequences for detection of Borrelia burgdorferi sensu lato.

An inherent drawback of nested PCR systems to increase sensitivity of PCR-based assays is that tubes must be opened after the first round of amplification in order to transfer template molecules to the second amplification reaction; this procedure introduces the risk of carry-over contamination of negative specimens. To obviate this disadvantage, a nested PCR assay for detection of Borrelia burgdorferi in which both amplifications are performed in a single tube that remains closed throughout the entire process was devised. The assay is based on flagellin gene sequences with previously determined species-wide and species-specific properties. The nested PCR system proved to be 1000 times more sensitive than the conventional assay. Using the nested PCR system, ten spirochaetes could be routinely detected by agarose gel electrophoresis alone, whereas the conventional PCR system could detect only 10(4) spirochaetes under these conditions. After Southern transfer on amplification products and hybridization with 320- or chemiluminescent-labeled probes, the nested PCR system could easily detect a single spirochaete by both means, whereas the sensitivity of the conventional PCR assay varied from 10(1) (32P) to 10(3) (chemiluminescence) spirochaetes. This single-tube nested PCR system should be a useful addition to the current range of diagnostic assays for Lyme borreliosis.

Base Sequence↗
PubMed1996

Molecular characterization of Borrelia burgdorferi sensu lato from Slovenia revealing significant differences between tick and human isolates.

One hundred twenty-nine Slovenian isolates of Borrelia burgdorferi sensu lato derived from patients (69 strains) or Ixodes ricinus ticks (60 strains) were characterized. All of the strains were first- or second-passage isolates obtained in 1992 and 1993 from the same endemic region. The techniques used for the molecular analysis of strains included species-specific polymerase chain reaction (PCR) typing, and pulsed-field gel electrophoretic separation of undigested and MluI-digested genomic DNA. Isolates were identified to the species level by large restriction fragment pattern (LRFP) analysis and the results compared with the species-specific PCR result. Fifty-two patient isolates (75%) were typed as Borrelia afzelii (LRFP MLa1), 6 (9%) as Borrelia garinii (LRFPs MLg1-4), and 11 (16%) as Borrelia burgdorferi sensu stricto. The latter included 9 isolates (13%) with a new LRFP that is not typical of Borrelia burgdorferi sensu stricto and for which the designation MLx is suggested. In contrast, only 32 of 60 (53%) tick isolates were typed as Borrelia afzelii, while 20 strains (33%) were typed as Borrelia garinii and 8 strains (13%) as Borrelia burgdorferi sensu stricto. Three new LRFPs were found among the Borrelia garinii (MLg5 and 6) and Borrelia burgdorferi sensu stricto (MLb15) tick isolates. Large restriction fragment pattern analysis identified new groups of Borrelia burgdorferi sensu lato and revealed an apparent difference in the isolation frequency of different species from patients and ticks in the same endemic region.

Animals↗
PubMed1996

MR findings in human fascioliasis.

Fasciola hepatica is a trematode of herbivorous mammals, and man is infected by accidental ingestion of contaminated raw aquatic vegetables or water. There have been many reports on computed tomographic and cholangiographic features of human fascioliasis. However, findings of magnetic resonance (MR) imaging have not been reported. Hepatic fascioliasis produces three types of lesions in MR images arranged in tract-like fashion. The outermost area presents as an iso-signal area in T1WI, with slightly higher signal intensity in T2WI and diffuse enhancement after i.v. contrast. The second type presents as a well defined low signal area in T1WI, not enhanced, and also shows low signal intensity in T2WI. The third type has low signal intensity in T1WI, is not enhanced, and has high signal intensity in T2WI which is similar to fluid-containing inflammatory lesions such as pyogenic abscess. These findings suggest various changes associated with traumatic hepatitis caused by the migration of the worm in the liver. This diverse signal intensity can be a suggestive finding of fascioliasis.

Fascioliasis↗
PubMed1996

Decomposition of alpha-lipoic acid derivatives by photoirradiation-formation of dihydrolipoic acid from alpha-lipoic acid-.

Due to its strained five-membered ring, alpha-lipoic acid (LA) has an absorption band around 330 nm, which is used to quantify its concentration. In order to obtain information for the homolytic rupture of the S-S bond and the formation of dihydrolipoic acid (DHLA), the photochemical reaction of lipoic acid was examined in the presence or absence of ascorbic acid upon exposure to UVA light. The absorption band of alpha-lipoic acid at around 330 nm disappeared by photoirradiation, which corresponds to the rupture of S-S bond of the 1,2-dithiolane ring in lipoic acid. HPLC-Electrochemical Detection (ECD) analysis of lipoic acid showed significant formation of dihydrolipoic acid and other thiols. The formation of thiols from the photoreaction of lipoic acid was also confirmed by the Ellman method. The formation of thiols from lipoic acid was completely time-dependent and the formation of the thiols increased upto 55%. Similar results were obtained in the photochemical reactions of short-chain analogues, bisnor- and tetranor-lipoic acid. On the other hand, beta-lipoic acid was quite stable, no photodecomposition of beta-lipoic acid was observed in the UV region. The formation of thiols including dihydrolipoic acid from lipoic acid can be explained by considering the rupture of S-S bond, which results in the formation of the dithiyl radicals of alpha-lipoic acid. It is proposed that intra- and intermolecular hydrogen abstraction of the dithyl radical produces thiols including dihydrolipoic acid as final products.

Antioxidants↗
PubMed1996

[Effects of endoscopic sinus surgery and relative factors].

The results of 296 endoscopic sinus surgery (ESS) from Oct. 1991 to May, 1993 were analysed. Pre- and post-operative examinations in this series were as follows: 1. Peripheral blood T lymphocyte subclusters test (100 cases): 2. Immunohistochemical test of nasal polyp (103 cases): 3. Pathologic examination of nasal polyp: 4. CT scan typing (103 cases). Men and women ratio was 2:1 and their ages varied from 7 to 72 years. 107 patients were given general anesthesia and 189 patients local anesthesia. The clinical stages of chronic sinusitis were divided as: 53.7% (N), 29.3% (II), 10.9% (III) and 6.1% (I). The clinical curative rate was 85.7% (126/147 cases), and improving rate was 99.3%. The standard of clinical stage of chronic sinusitis, the relative factors of prognosis with the results of ESS, pathological test, immunohistochemical test and follow-up after ESS were discussed.

CD4-CD8 Ratio↗
PubMed1996

[Investigation of infiltrating lymphocytes and immunoglobulin by immunohistochemical method in cheilitis granulomatosa].

Category and distribution of infiltrating lymphocytes and immunoglobulin in 12 cases with cheilitis granulomatosa (CG) and 4 cases with Melkersson-Rosenthal syndrome (MRS) were investigated. The result was that infiltration of lymphocytes in granulomatous type was more severe than that in interstitial inflammtion type. Infiltrators mainly consisted of T helper lymphocytes and immunoglobulin was IgM. It was considered that local immunoreaction was enhanced suggesting that cyto-immunity was a dominant factor with participation of humoral immunity. The result will be helpful to elucidate the pathogeneses and the function of many immuno-factors in the CG. It helps to understand the clinical manifestations and may be a theoretic reference for seeking immuno-modulation for treatment.

Humans↗
PubMed1996

[The cellular immunologic status of the laryngeal cancer patients].

To observe the cellular immunologic status of the laryngeal cancer patients 70 laryngeal cancer patients were examined with immunohistochemical method. The peripheral blood T lymphocyte subsets were detected and local tumor infiltrative T lymphocytes were observed. The results showed that the cellular immunologic function of laryngeal cancer patients was lower than that of the healthy persons and the function of late staged patients was lower than that of the early staged patients. The pattern of changes of these two observations was of the same trend. The clinical significance of the examinations was discussed.

Adult↗
PubMed1996

[The relationship between human chorionic gonadotrophin and lipoprotein metabolism].

We compared human chorionic gonadotrophin (hCG-beta) with lipids, lipoproteins and apolipoproteins in serum between pre- and postmenopausal women, and observed the changes of levels of hCG-beta in animals suffering from hypertriglyceridemia. The results have shown that the concentration of hCG-beta in postmenopausal women is much higher than that in premenopausal women (P < 0.001). Correspondingly, triglyceride (TG) is elevated (P < 0.05). High density lipoprotein cholesterol (HDL-C) and HDL-C/LDL-C ratio are decreased (P < 0.001, P < 0.01). On the other hand, the tendency of highing hCG-beta level has been found in animal study. The concentration of hCG-beta in male rats suffering form hypertriglyceridemia is higher than that in normal animals (P < 0.05).

Adult↗
PubMed1996

[Treatment outcome of 1,000 cases of endoscopic sinus surgery].

To assess the treatment outcome of endoscopic sinus surgery (ESS), 1,000 patients with chronic sinusitis and nasal polyp treated between November 1991 and January 1995 were included in this study. Among them, 754 patients (64.8%) had previous operations from 1 to 25 times with an average of 3.7. Before ESS, axial and coronal CT scans were obtained (window width: 1,000 HU, window level: +90 HU; section thickness: 2 mm with 12 to 16 sections). Patients with clinical stages from I to IV were 9.9%, 21.0%, 15.0% and 54.1% respectively. Bilateral ESS was performed in 95% patients, septoplasty in 27.6%, middle meatal antrostomy in 78.5%. The clinical cure rate was 84.0%, 557 patients were considered as primary healing, 283 patients delayed healing and 160 patients had persistent inflammation. Complications were noted in 18 patients. Bleeding during ESS varied from 10 to 1,800 ml (average 180 ml). The indications, preoperative evaluation, control of bleeding, prevention of complications and prognosis were discussed in detail. The article indicated that the important factors to increase the cure rate are postoperative follow-up and systematic treatment.

Adolescent↗
PubMed1996

[Endoscopic CO2 laser treatment for the decannulation difficulty after vertical laryngectomy].

Sixteen patients with the decannulation difficulty after vertical laryngectomy were treated by endoscopic CO2 laser. The rate of decannulation was 87.5% (14/16). The curative effect was stable after 1-3 years. The causes of the decannulation difficulty included the over growth of granulation tissue, scar formation and bulky of the muscle flap. The result showed that endoscopic CO2 laser is an effective modality in the treatment of the decannulation difficulty after vertical laryngectomy.

Adult↗