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Biomedical subjects

X Tang

Publications and source records attributed to X Tang.

At least 199 records · Page 11Linked to original sources

Fatal interstitial pulmonary disease in a patient with dyskeratosis congenita after allogeneic bone marrow transplantation.

Chronic restrictive lung disease in a 9-year-old boy with dyskeratosis congenita (DC) 7 years after allogeneic bone marrow transplantation (BMT) is described. When he was 1 year and 10 months old, severe aplastic anemia developed. He received a marrow transplant from his HLA serologically identical, but HLA-DP mismatched brother. He developed grade II acute graft-versus-host disease (GVHD) and thereafter chronic GVHD of progressive type, and was treated with both prednisolone and azathioprine resulting in clinical improvement. Thereafter he complained of dyspnea, and bilateral noncircumscribed interstitial shadows on chest CT scan were present. His pulmonary function showed restrictive changes. Prednisolone was not effective and he died of respiratory failure. Post-mortem examination confirmed interstitial fibrosis, lymphocytic infiltration of the bronchioles and alveoli with luminal fibrosis. There was no evidence of chronic GVHD in the skin and the liver. These findings raise the possibility that this pulmonary complication was associated with DC itself.

Anemia, Aplastic↗

Epstein-Barr virus (EBV)-induced CD30+ natural killer cell-type malignancy resembling malignant histiocytosis: malignant transformation in chronic active EBV infection associating hypogammaglobulinemia.

A 27-year-old male suffered from Epstein-Barr virus (EBV)-related liver dysfunction with persistent hypogammaglobulinemia. IgG titers to EBV antigens were significantly high, while other hepatitis markers were negative. Liver biopsy disclosed active intralobular inflammation. Two years later, he manifested persistent fever, leukopenia, effusions and hypoproteinemia, and his general condition worsened progressively. The peripheral blood small lymphocytes predominantly expressed natural killer (NK)-like phenotypes (CD2+, CD7+, CD16+, CD56+). Hepatosplenomegaly and marked elevation of serum lactic dehydrogenase were observed. He died of respiratory failure at the age of 29. At autopsy, the liver (2190 g), spleen (860 g), small bowel and mesenteric lymph nodes showed massive infiltration of large atypical lymphoid cells in close association with hemophagocytic histiocytes. Involvement was mildly noted also in the bone marrow, lungs, gall-bladder and kidneys. The atypical cells belonged to CD30+ activated NK-type cells expressing CD2, cytoplasmic CD3 epsilon, CD7, CD45RO, CD56, HLA-DR and HLA-DQ. T cell receptors (TCR), surface CD3, CD4, CD5 and CD8 were not expressed. Epstein-Barr virus-related small nuclear RNA (EBER1) and Epstein-Barr virus-associated nuclear antigen 1 were detected in the nuclei of a significant number of atypical cells, while EBV-related latent membrane protein-1 was negative. EBER1 was also identified in the nuclei of non-neoplastic small lymphocytes at both biopsy and autopsy. Monoclonal integration of the EBV genome into the lymphoma cells was shown by Southern blot analysis. Clonal rearrangement of TCR was undetectable. Roles of chronic active EBV infection in the development of NK cell-type malignancy resembling malignant histiocytosis are discussed.

Adult↗

Detection of Pneumocystis carinii DNA in air samples: likely environmental risk to susceptible persons.

The means by which humans acquire Pneumocystis carinii is not well understood. Whether it can be acquired from specific environmental sources or transmitted from person to person has not been determined. This study was designed to detect nucleic acids of P. carinii in air samples from various locations, including P. carinii-infected patients' homes and hospital rooms, non-P. carinii-infected patients' hospital rooms, empty hospital rooms, offices at Indiana University, and other homes in different locations. DNA was extracted from cellulose-ester filters through which air samples had been filtered, and the P. carinii DNA was amplified by PCR with primers specific for the internal transcribed spacer regions of rRNA. P. carinii DNA was found in 17 of 30 air samples (57%) from the rooms of P. carinii-infected patients. It was also found in 6 of the 21 other hospital rooms sampled (29%) but was not found in any of the offices, storage areas, or control homes. Environmental sampling suggests that the airborne presence of P. carinii genetic material and infectious organisms is plausible. The organism was also detected in locations where P. carinii patients were not immediately proximate, such as the hospital rooms of non-P. carinii-infected patients.

Air Microbiology↗

A single-tube nested PCR for Pneumocystis carinii f. sp. hominis.

A single-tube nested PCR which amplifies the internal transcribed spacer (ITS) regions of the rRNA genes of human Pneumocystis carinii was developed. The outer primers for the first PCR, which anneal to the 18S and the 26S rRNA genes of P. carinii, were made to have a midpoint temperature (Tm) of 74 degrees C. The inner primers for the second PCR have a Tm of 56 to 58 degrees C and are specific for human P. carinii; they anneal to an area close to the beginning of ITS1 and the junction of ITS2 and the 26S rRNA genes. The reaction mixture contained 2.5 pmol of the first-PCR primers and 25 pmol of the second-PCR primers. The first PCR was performed at an annealing temperature of 68 degrees C, which did not allow the second-PCR primers to function. Since very small amounts (2.5 pmol) of the first-PCR primers were used, they were exhausted when the first PCR was completed. The single-tube nested PCR did not amplify P. carinii isolated from rats, mice, or ferrets. All 10 bronchoalveolar lavage (BAL) specimens from patients with P. carinii pneumonia were positive, whereas all 10 BAL specimens from patients with other diseases or patients infected with several commonly found fungi were negative by PCR.

Animals↗

[A clinical study of correlation between ablation depth and corneal subepithelial haze after photorefractive keratectomy].

OBJECTIVE: To assess the correlation between excimer laser ablation depth and corneal subepithelial haze in correction of myopia. METHODS: The results of 31 cases (62 eyes) of myopic anisometropia on whose both eyes photorefractive keratectomy (PRK) was performed at the same time were analyzed. The bilateral eyes of each patient were divided into two groups: The lower myopic eyes (-9.13 +/- 3.53 D) were in the control group and the higher myopic eyes (-14.10 +/- 4.17 D) in the treatment group. The follow-up periods were 6 to 12 months (mean, 10 months). RESULTS: There is significant difference (P < 0.05) in the haze between the two groups after PRK. CONCLUSION: The higher the correction of myopia, the more dangerous the occurrence of the haze following PRK.

Adult↗

[Diagnostic value of pleuro-examination with fiberoptic bronchoscope in indefinite pleural effusions].

The diagnostic value of pleuro-examination with fiberoptic bronchoscope in indefinite pleural effusions was studied. Pleuro-examination with fiberoptic bronchoscope has been performed in 10 cases with indefinite pleural effusions, and its diagnostic value and complications have been observed. The results showed that the diagnoses were confirmed in 9 of 10 patients submitted to pleuro-examination, and no severe complications were found. The results suggest that pleuro-examination with fiberoptic bronchoscope is an effective and safe procedure and might be performed on patients with pleural effusions when routine examinations fail to provide a diagnosis.

Adenocarcinoma↗

[A simple and rapid method of preparing cell or tissue embedded in situ for transmission electron microscopy].

A simple and rapid method of preparing cell or tissue embedded in situ for transmission electron microscopy (TEM) is recommended. It is very simple; all procedures, including fixation, dehydration, infiltration and embedding, are performed on the same carrier (culture vase or microscope slides). It is also very rapid; the whole process takes only five hours. The entire cell or tissue embedded in situ is easily separated from the carrier. The ultrastructures of the cell or tissue embedded in situ are well preserved with minimal damage. This method can be used in preparing cultured monolayer cell for TEM study, paraffin section for electron microscopic diagnosis, and frozen section for TEM immunohistochemistry or enzymehistochemistry. The main points of the procedures of preparation have been discussed.

Humans↗

[The value of erythromycin pleurodesis in the treatment of malignant pleural effusions].

Malignant pleural effusion is a frequent complication of patients with advanced malignant tumors. For many patients suffering from malignant pleural effusion that increases rapidly and may be life threatening, it is important to control the effusions. To investigate the value of erythromycin as a pleural sclerosant, a dose of 1 g erythromycin in 30 ml of 5% glucose was injected into the pleural cavity of 26 patients with malignant pleural effusion. The results were assessed by Miller's standards. After treatment, numerous adhesions were present in 15 cases; Pleural effusion reduced in 7 patients, and no effect was noted in 4 patients. The total response rate was 84.6%, and there were no severe side-effects. The erythromycin-induced pleurodesis is probably the result of induced chemical inflammation in the locality. This study suggests that erythromycin is a useful pleural sclerosant.

Adenocarcinoma↗

[Comparative study on the erect and fallen types of Platycodon grandiflorum (Jacq.) DC].

Based on botanica characters, phenophase, yield and content of active constituents, the erect and fallen types of platycodon grandiflorum were compared. The results show that the comprehensive characters of erect type are better than those of fallen type and the erect type is therefore good for popularization. Some specific characters of the fallen type are better than those of the erect type, and the fallen type is therefore to be preserved as one of the germ plasm resources.

Glucose↗

[Reinnervation of pectoralis major myoflap by the hypoglossal nerve: an experimental study in rabbits].

In order to investigate the morphological, electrophysiological and histochemical characteristics of the pectoralis major myoflaps with original nerve innervation and with hypoglossal nerve reinnervation, after denervation, the model of myoflap transposition to reconstruct the tongue was adopted on 27 New Zealand white rabbits. After the myoflaps were transferred, original nerve innervation (ON), hypoglossal-genioglossus muscle branch nerve implantation (NI) and hypoglossal-genioglossus muscle neuromuscular pedicle implantation (NMP) were performed. The flaps were examined at the intervals of 4, 8, 12 weeks and 16 weeks after operation. The results showed that the denervated myoflaps were reinnervated in NI and NMP, myoflaps contracted when the hypoglossal nerves were stimulated. The histochemical properties of muscle fibers changed. Some type II fibers in the myoflaps transformed into type I fibers, but the pattern of distribution of the muscle fibers displayed mosaic and was similar to that of genioglossus muscle. In terms of speed and scope of reinnervation, the NMP was superior to the NI.

Animals↗

[Comparative study on three different methods in typing hepatitis C virus].

The sea from 120 anti-HCV-positive patients were detected by three different methods to type HCV. In method A, PCR product of 5'-NC region was cut by restriction endonuclease. In method B, PCR with HCV core region type-specific primers was used. In method C, EIA based on HCV genotype I, II (serotype 1) and genotype III, IV (serotype 2) synthetic peptides was used to detect type-specific antibodies. It was showed that HCV genotypes were successfully identified in 96(80%) patients both by method A and method B, with HCV-II 86(89.6%), HCV-III 8(8.3%), HCV-II/III coinfection 2(2.1%). The results of these two methods were completely agreeable. HCV type-specific antibodies were detected in 78(65%) cases by method C, with serotype 1 68(87.2%), serotype 2 6(7.7%), serotype 1 plus 2 positive 4(5.1%). The comparative estimation of 66 patients who were positive for all the three methods showed a remarkable concordance (64/66, 97.0%). Our study demonstrated that the results of different HCV-typing methods mentioned above were fairly consistent and reliable. The abvantages, disadvantages and practical applicable scope of these methods were discussed in the paper.

Genotype↗

[A rapid method for diagnosing alpha-thalassemia-1 of Southeast Asia type].

OBJECTIVE: To explore a rapid method for diagnosing alpha-thalassemia-1 of Southeast Asia type. METHODS: Seventy-six patients were detected by polymerase chain reaction (PCR). RESULTS: Thirty-one patients were diagnosed as alpha-thalassemia-1 of Southeast Asia type. PCR was compared with polyacrylamide gel electropheresis for detecting zeta-globin chain in 56 patients and the correspondance rate was 83.93%. Ten cases of prenatal diagnosis were performed by PCR, and the results showed that one was Hb bart's hydrop fetalis, four were carriers of alpha-thalassemia-1 of Southeast Asia type, and the others were normal fetalis or carrier of alpha-thalassemia-2. CONCLUSION: The PCR method is simple and accurate for diagnosing alpha-thalassemia of Southeast Asia type, and it provides a new approach to the prenatal diagnosis of alpha-thalassemia fetalis and the detection of alpha-globin gene cluster.

Adolescent↗

[Colony-stimulating activities of serum from patients with severe aplastic anemia].

OBJECTIVE: To investigate the correlation between colony-stimulating activities of serum from patients with severe aplastic anemia (SAA) and their responses to immunosuppressive therapy (IST). METHODS: In vitro effects of sera from SAA patients before and after IST and from normal subjects on human marrow colony growth were examined in a semisolid methylcellulose culture system for burst promoting activity (BPA) and granulocyte/macrophage colony-stimulating activity (GM-CSA). Serum erythropoietin (Epo) level was also measured by ELISA method before and after IST in SAA patients. RESULTS: Serum BPAs in SAA patients at diagnosis were significantly higher than that in normal controls (P<0.001), but serum GM-CSAs in 13 of 22 SAA patients were normal,and in 9 of 22 extremely low as compared with normal values. After IST, serum BPA and GM-CSA in SAA patients had no changes. Serum Epo levels in SAA patients at diagnosis were significantly higher than that in normal controls (P<0.001). After IST,serum Epo levels declined in responded patients, while further increased in nonresponded. CONCLUSION: Serum GM-CSA of SAA patients was a predictive factor for responsiveness to IST, and a normal value was associated with a good response.

Anemia, Aplastic↗

[HLA-DR-positive T lymphocytes in the bone marrow and peripheral blood of patients with severe aplastic anemia and their in vitro inhibitory effecton BFU-E and CFU-GM].

OBJECTIVE: [corrected] To elucidate the role of immunodysfunction in the pathogenesis of severe aplastic anemia (SAA). METHODS: HLA-DR+ T cells were detected in bone marrow (BM) and peripheral blood (PB) of 20 SAA patients and controls (9 for BM and 11 for PB). PHA-LYCM conditioned medium was prepared, and its in vitro effect on normal bone marrow BFU-E and CFU-GM was studied. RESULTS: The percentages of HLA-DR+ T lymphocytes in BM and PB of newly diagnosed SAA patients were significantly higher than that of controls (P<0.001), and that of recovered SAA (rSAA) patients after ALG therapy (P<0.05). Compared with controls, the PBA-LYCMs from newly diagnosed SAA patients showed significant inhibitory effect on normal BFU-E and CFU-GM (P<0.001). CONCLUSION: The activated T lymphocyte may play an important role in the pathogenesis of SAA.

Adolescent↗

[Colony formation of bone marrow hematopoietic progenitor cells in patients with severe aplastic anemia and its relation to the results of immunosuppressive therapy].

OBJECTIVE: To explore the defect of hematopoietic stem cell and analyze the relationship between the colony formation capacity of bone marrow hematopoietic progenitor cells and the results of immunosuppressive therapy (IST) in severe aplastic anemia (SAA) patients. METHODS: Methylcellulose semisolid culture was used. RESULTS: Thirty patients with SAA at diagnosis were studied. In 90% of the patients, the CFU-E and CFU-GM yields were strikingly decreased and in 56.7% of the patients there was no colony formation at all. Nevertheless, there was still 10% of the patients having normal CFU-E, BFU-E or/ and CFU-GM yields. After IST, 59.1% of the patients showed colony formation improvement. The difference between the results obtained pre- and post-IST(for CFU-E and BFU-E, P < 0.01, for CFU-GM, P < 0.05) was significant. In the majority of the patients, the colony formation capacities were still under the normal post-IST. Moreover, 22.7% of the patients remained no colony formation post-IST. The IST response rates between the patients with or without colony formation had no statistically difference (80% versus 50%, P < 0.05). The increment of colony formation appeared later than the therapeutic effect did, but frequently concurred with the appearance of magkaryocytes in the bone marrow smear. CONCLUSION: In the majority of SAA patients, the hematopoietic stem cells or progenitors were defective perhaps caused by immune damage; IST can improve the hematopoiesis in vitro and in vivo of SAA patients.

Adolescent↗