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Biomedical subjects

T Sun

Publications and source records attributed to T Sun.

At least 37 records · Page 2Linked to original sources
PubMed1991

Diagnostic value of lactate dehydrogenase isoenzymes in cerebrospinal fluid.

To evaluate the diagnostic value of lactate dehydrogenase (LD) isoenzymes in cerebrospinal fluid (CSF), 93 consecutive CSF specimens were analyzed. These specimens were from patients of four categories: tumors, infections, hemorrhages, and others. It was found that the isoenzyme patterns overlapped among different categories, but they differed within each category and were thus helpful in differential diagnosis. For instance, metastatic tumors showed prominent LD-5, whereas a primary brain tumor demonstrated an increase in all fractions. Viral encephalitis revealed an increase in the first three isoenzymes and bacterial meningitis, the last two. In acquired immune deficiency syndrome (AIDS) cases, however, LD isoenzyme changes were demonstrated in CSF when only cryptococcal meningitis and not when encephalitis was present. Both subdural and subarachnoid hemorrhages showed elevation of all fractions in our study. Elevation of the first three fractions was usually due to brain tissue damage or hemorrhage, as proven by our isoenzyme study of hemolysate mixed with CSF. The prominence of the last two fractions was related to anaerobic metabolism in the central nervous system or to granulocytic infiltration. In conclusion, LD isoenzyme analysis in CSF is helpful in differential diagnosis of various CNS disorders, although its sensitivity awaits further improvement.

Adult↗
PubMed1991

Enterobius egg granuloma of the vulva and peritoneum: review of the literature.

Two cases of Enterobius granuloma containing eggs only are reported. The first case involved the vulva, where no such granuloma has been reported previously. The coexistence of peritoneal granuloma and rectal adenocarcinoma in the second case suggests the possibility of direct penetration of the damaged colonic wall by the parasite, as emphasized by several previous reports of neoplastic involvement and perforation of the intestinal wall in cases of ectopic infections. The diagnostic criteria of Enterobius eggs granuloma, which might be a diagnostic dilemma for pathologists who are not familiar with such criteria, are described herein.

Adult↗
PubMed1991

Effects of Cordyceps sinensis on murine T lymphocyte subsets.

It was shown by flow cytometry analysis that crystalized preparation of Cordyceps sinensis (Cs-Cr) caused significant elevation of the number of T helper cells and Lyt-1/Lyt-2 (T helper to T suppressor cell) ratio both in peripheral blood and the treated mice spleen. The spleen weight, phagocyte counts and phagocytic activity were also elevated in the treated group. In addition, Cs-Cr could protect T helper cells from the immunosuppressive effects of prednisolone acetate and cyclophosphamide. These results further substantiate the fact that Cs-Cr is an immunoregulator/biological response modifier of cellular immunity and may be potentially useful in handling immunodeficient or immunosuppressed patients.

Animals↗
PubMed1991

[Clinical application of the ophthalmic high frequency ultrasonic B-scan diagnostic equipment].

800 eyes were examined with the ophthalmic high frequency ultrasonic B-scan diagnostic equipment. The results were confirmed by medication, optical examination, CT, surgical operation, or pathology at a rate of 93.3%. The authors discussed the acoustic characteristics of the ultrasonic image of common ocular diseases and its functional characteristics. It was believed that the equipment markedly enhanced the diagnostic capability of ultrasound in ophthalmology.

Adolescent↗
PubMed1991

Hand-mirror variant of microgranular acute promyelocytic leukemia.

We report a case of microgranular acute promyelocytic leukemia (APL, M3 V) presenting with the typical features of disseminated intravascular coagulopathy and cells with irregular, folded, or bilobed nuclei with occasional intracytoplasmic multiple Auer rods in the peripheral blood. A cytogenetic study of the bone marrow and blood showed translocation between chromosomes 15 and 17, characteristic of APL. The flow cytometric study also confirmed this diagnosis. The unusual feature in this case is the existence of 80% hand-mirror cells, which also contain multiple Auer rods, in the bone marrow. The hand-mirror variant of acute leukemia has been frequently encountered in acute lymphoblastic leukemia, but documented in only six cases of acute myelogenous leukemia, including the FAB groups of M1, M2, M4, and M5. This patient is, to our knowledge, the first reported case of a hand-mirror variant in microgranular APL. The mechanism of hand-mirror cell formation and its prognostic implication are discussed.

Bone Marrow↗
PubMed1990

Extranodal T-cell lymphoma mimicking malignant histiocytosis.

We report a case of extranodal T-cell lymphoma with fever, hepatosplenomegaly, pancytopenia, and diffuse sinusoidal infiltration of the spleen, liver, and bone marrow by the tumor cells, mimicking malignant histiocytosis. This is the second case of T-gamma (T-cell suppressor) lymphoma resembling the case reported by Kadin et al. [N Engl J Med 304:648, 1981]. The lack of lymph node involvement in this case supports the theory that this type of lymphoma arises in the spleen. This paper draws attention to the extranodal T-cell lymphoma groups that mimic malignant histiocytosis and the need of immunophenotyping for a correct diagnosis. The causes for the absence of T-cell receptor gene rearrangement in T-cell tumors are discussed.

Adult↗
PubMed1990

The clonal origin of two cell populations in Richter's syndrome.

A case of Richter's syndrome was studied by morphology, immunohistochemistry, flow cytometry, and immunoglobulin gene rearrangement. Flow cytometric study clearly demonstrated two monoclonal populations. The use of double staining with CD 5/CD 19 antibodies accompanied by two-color flow cytometric analysis clearly defined the chronic lymphocytic leukemia population and separated it from the lymphoma population. Immunoglobulin heavy-chain gene analysis of blood and lymph node specimens revealed nonidentical as well as identical nongermline bands in these two populations. However, light-chain gene analysis demonstrated that both populations shared a common clonal origin. This result underscores the unreliability of using heavy chain genotype alone to identify clonal origin. Since post-rearrangement deletion, point mutation, and heavy chain switching occur in heavy chain genes, but are seldom seen in light chain genes, it is important to analyze both heavy and light chain genes to conclusively determine clonal origin.

Antigens, CD↗
PubMed1990

[Dot-ELISA in the diagnosis of neurocysticercosis].

The dot-enzyme-linked immunosorbent assay was used to detect Cysticercus cellulosae antibodies in sera of patients with neurocysticercosis. Among 108 confirmed cases of neurocysticercosis 81.6-96.1% showed positive reactions. Two out of 54 normal control sera reacted at a serum dilution of 1:20, but none at a 1:40 (range 40-640). No cross reactions were observed with sera from cases of paragonimiasis and clonorchiasis, but it did occur to some extent with sera from cases of echinococcosis and cerebrovascular diseases. The results indicated that the dot-ELISA was sensitive, specific and economic for the diagnosis of neurocysticercosis.

Animals↗
PubMed1989

Comparison of phenotyping and genotyping of lymphoid neoplasms.

Comparison of phenotyping (PT) and genotyping (GT) of lymphoid neoplasms was performed on 51 specimens including lymph nodes, bone marrows, and body fluids. PT was performed with a flow cytometer using a large monoclonal antibody panel. GT included the testing for gene rearrangements of heavy chain, kappa and lambda light chains, and T-cell receptor beta-chain genes with DNA probes. The results obtained from these two techniques were generally compatible in terms of clonality and cell lineage. Only one case of B-cell lymphoma was not diagnosed by PT but showed gene rearrangement. For T-cell lymphoma, GT offers a more definitive diagnosis than does PT. Biclonality was demonstrated in one case of hairy cell leukemia by GT only. The rearranged band also offers a definitive clonal identification based on electrophoretic mobility. GT can detect a monoclonal population as small as 5% and can be performed on old or fresh specimens. PT requires 20% abnormal cells and a fresh specimen. It is concluded that GT is superior to PT for lymphoid tumor diagnosis, but it should be reserved as a supplementary test at this stage because of its technical complexity.

Antibodies, Monoclonal↗
PubMed1989

Improved immunohistochemical detection of prostatic acid phosphatase by a monoclonal antibody.

A monoclonal antibody with high affinity to acid phosphatase isoenzyme 2 (Ab-AcP2) was selected to examine its binding to different normal and tumor tissues using the indirect immunohistochemical method. Both mature prostatic epithelial cells in the prostate and the highly dedifferentiated prostatic cancer cells in the bone marrow showed strong binding to the antibody. Among nonprostatic tissues, only bone marrow, breast, and kidney showed trace staining in some specimens. The specificity of Ab-AcP2 was much better than that of the polyclonal antibody to acid phospatase previously reported. When the antibody to the prostate-specific antigen (Ab-PSA) was used, weak background staining was often encountered, and weak to moderate stains were seen in the prostatic stroma, bone marrow, lung, skin, and melanoma.

Acid Phosphatase↗
PubMed1989

Questionable clinical significance of Blastocystis hominis infection.

In the period from January 1986 to July 1988, Blastocystic hominis was found in moderate and numerous quantities in 103 (1.6%) of 6,262 stool specimens examined in our laboratory. There was no significant association of the detection of B. hominis with travel history or symptoms. Indeed, 20 patients (36%) with moderate to heavy infections had no gastrointestinal symptoms, and three symptomatic patients did not show clinical improvement after elimination of the parasite. Reexamination of stool samples revealed that eight untreated patients had spontaneous disappearance of B. hominis. We conclude that B. hominis probably is not responsible for clinical symptoms when detected, and additional investigations should be pursued for other etiologies of the patient's symptoms.

Adult↗
PubMed1988

A monoclonal antibody to a human neutrophil-specific plasma membrane antigen. Effect of the antibody on the C3bi-mediated adherence by neutrophils and expression of the antigen during myelopoiesis.

We have used mice selectively tolerized to antigens of human lymphocytes by treatment with cyclophosphamide to raise an mAb, BH2-C6, that reacts with a plasma membrane antigen specific for human neutrophils. This specificity is demonstrated by indirect immunofluorescence microscopy, cytochemical analysis of fluorescence-positive and -negative cell populations separated by flow cytometry, and by the selective, complement-mediated killing of mAb BH2-C6-treated neutrophils. Additional evidence for the neutrophil specificity of mAb BH2-C6 is shown by immunoelectron microscopy, which demonstrates a lack of reactivity with human eosinophils. Immunoblotting of SDS-PAGE-separated proteins of polymorphonuclear leukocytes with 125I-labeled BH2-C6 identifies protein with an average molecular mass of 157 kD. Binding studies show that, at saturation, neutrophils bind 214,000 molecules of 125I-BH2-C6 per cell. Addition of mAb BH2-C6 to neutrophils significantly reduces the number of C3bi-opsonized sheep erythrocytes (EIgMC3bi) bound by these cells. This reduction is partly reversed by the presence of soybean trypsin inhibitor (SBTI), indicating that at least one part of this inhibition is due to BH2-C6-stimulated secretion of a serine protease that may affect ligand binding. Cytochemical analysis of normal human bone marrow cells sorted by cytofluorimetry identifies the promyelocyte as the precursor cell that first expresses BH2-Ag on the plasma membrane. Using the leukemic cell line HL-60, we demonstrate that only inducers of granulocytic differentiation, cis-retinoic acid, and dimethyloxazolidine stimulate the expression of BH2-Ag. These results show that the expression of BH2-Ag during myelomonocytic differentiation is a property uniquely possessed by cells committed to the neutrophilic lineage.

Animals↗
PubMed1988

Protozoal infections in the acquired immunodeficiency syndrome.

Several protozoa have emerged as the major opportunistic infections and cause of death in patients with acquired immunodeficiency syndrome (AIDS). Pneumocystis carinii pneumonia is the leading cause of death in AIDS patients. Electron microscopy (EM) usually shows numerous trophozoites and cysts of Pneumocystis filling up the entire alveolar space, while only cysts are seen under the light microscope. The focal thickening of cyst wall of Pneumocystis, as demonstrated by EM and manifested as a "parentheses" shaped structure with silver stain, serves as a diagnostic marker for Pneumocystis. Freeze-fracture EM has demonstrated the intimate contact between Pneumocystis trophozoites and the type I pneumocytes, which may contribute to the alveolar-capillary block, leading to severe respiratory distress. However, EM is seldom needed for the diagnosis of this infection. Toxoplasma encephalitis, which is an unusual clinical manifestation in cases of toxoplasmosis reported previously, has become a common complication and one of the major causes of death in patients with AIDS. Because subclinical infection by Toxoplasma is common, serologic tests usually offer no definite answers as to whether the infection is acute or chronic, active or past. The small size and its non-specificity in both morphology and tissue affinity make light microscopic diagnosis of toxoplasmosis difficult. Only immunologic staining, such as immunoperoxidase and immunofluorescence, can help to achieve a definite positive identification of the organism. When special antibodies or facility for such staining is not available, EM is the final resort for identifying Toxoplasma by showing the apical complex with the characteristic sausage-shaped rhoptries. Cryptosporidiosis, practically unknown before the AIDS outbreak, has become one of the most common intestinal protozoa in both immunocompromised and immunocompetent patients. The protracted and sometimes fatal course of cryptosporidiosis in immunocompromised patients can be explained by the presence of autoinfective oocysts (thin-walled oocysts), as detected by EM, and by recycling of first-generation schizonts observed experimentally. While diagnosis of cryptosporidiosis can be made by detection of oocysts in stools in most cases, EM is still the last resort for a definitive identification of Cryptosporidium species. While the incidence of isosporiasis is still low, it has been found more frequently in patients with AIDS than in the general population. The parasite, Isospora belli, being a coccidian as is the Cryptosporidium species, is similar to the latter in its life cycle and clinical manifestations.(ABSTRACT TRUNCATED AT 400 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1988

Physical characteristics of the M.D. Anderson Hospital clinical neutron beam.

The physical characteristics of the M.D. Anderson Hospital (MDAH) clinical neutron beam are presented. The central-axis percent depth-dose values are intermediate between a 4 and 6 MV X-ray beam. The build-up curves reach a depth of maximum dose at 1.2 cm and have surface dose values of approximately 30%. Teflon flattening filters are employed to flatten the beam at the depth of the 75% dose level. Two wedges are available for shaping the beam; they are made of Teflon and produce wedge angles of 31 degrees and 45 degrees as defined by the ICRU. Output factors ranged from 0.88 for a 4 x 4 cm field to 1.12 for a 20 x 20 cm field. Tungsten blocks reduced the dose received at Dmax to 25% of the unblocked value but only 52% of the unblocked value at a depth of 22.8 cm.

Filtration↗