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Biomedical subjects

S Kon

Publications and source records attributed to S Kon.

At least 109 records · Page 6Linked to original sources
PubMed1984

Revascularization following a combined gingival flap-split thickness flap procedure in monkeys.

A combined technique (gingival flap-split thickness flap) was performed in monkeys. The clinical, histological and microvascular aspects of healing were studied, mainly focusing on the gingival flap, since some of the vessels supplying this area were severed during the second phase of the procedure. The animals were perfused with a combined solution of Pelikan carbon black and 10% formalin solution and killed from 1 to 35 days postoperatively. Cleared specimens and regular histology were obtained. It was concluded that: (1) the remaining periosteal vessels and surrounding structures provided enough nutrition for the survival of the gingival flap, (2) the microvascularization was normal at the 14 days postoperative period in both the gingival flap and the apically positioned split areas and (3) the exposed connective tissue remained narrow and exhibited an irregular vascular arrangement throughout the experiment.

Animals↗
PubMed1984

Revascularization following the lateral sliding flap procedure.

Two young adult rhesus monkeys, with an average weight of 12 pounds were used. Anesthesia with Nembutal 30 mg/kg of body weight was given to perform the surgeries. Artificial defects were created by raising a flap and removing about 5 X 7 mm of the buccal alveolar plate and suturing the flaps exposing the alveolar crest. These defects were left untreated for 2 months. Then, mucogingival lateral sliding flaps were performed to cover the recessions. Postoperative periods of 1, 9, 14, 21, 28 and 35 days were obtained when the animals were killed. A combined solution of Pelikan carbon black and 10% buffered formalin was perfused through the exposed and cannulated external carotid arteries to evaluate revascularization. After killing, blocks, including the operated teeth and the surrounding tissues, were fixed in 10% formalin and then partially decalcified in EDTA. Two blocks per time interval were obtained. One of the blocks was processed for regular histology, and sectioned bucco-lingually. In these sections it was found that the new attachment to the root was mediated by a combination of connective tissue attachment and a long junctional epithelium. The other blocks were cut cross-sectionally at about 1-mm thickness. Sections were selected from three different areas: (a) at the most coronal part of the laterally displaced flap, (b) at the middle of the localized defect and (c) at the bottom of the defect. They were cleared following the Spalteholtz method.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1984

Rat T lymphocyte antigens comparable with mouse Lyt-1 and Lyt-2,3 antigenic systems: characterization by monoclonal antibodies.

Rat T lymphocyte antigens were defined by using two distinct monoclonal antibodies (R1-3B3 and R1-10B5). R1-3B3 antibody, when tested for its reactivity with rat lymphoid cells by immunofluorescence, stained almost all of thymus and T cells but not the majority of B cells and bone marrow cells. The antigen defined by R1-3B3 existed more abundantly on medullary thymocytes and peripheral T cells than on cortical thymocytes. Immunochemical data showed that R1-3B3 antibody recognized a single glycoprotein with a m.w. of 67,000, showing marked electric charge heterogeneity with isoelectric points ranging from 5.4 to 7.3. R1-10B5 antibody, on the other hand, had more restricted reactivity with rat T cells and labeled approximately 85% of thymus cells and 30% of the peripheral T cells but neither B cells nor bone marrow cells. These T cells positive for R1-10B5 appeared to be negative for W3/25 antigen, which has been shown to be the marker for the rat T cell subset associated with helper function. R1-10B5 antibody detected a basic glycoprotein complex consisting of sulfhydryl-linked subunits with 30,000 and 34,000 m.w. Although the antigen defined by R1-3B3 was resistant to trypsin digestion, the one detected by R1-10B5 was much more sensitive to trypsin cleavage. All of these data obtained with either R1-3B3 or R1-10B5 are quite comparable to those reported for mouse Lyt-1 or Lyt-2,3 antigens, and thus suggest that the antigens defined by R1-3B3 and R1-10B5 antibodies represent rat homologues of Lyt-1 and Lyt-2,3 antigens in the murine system, respectively.

Animals↗
PubMed1983

Fibrin and collagen deposition and fibroblasts proliferation in granuloma of murine leprosy. Comparison of two mouse strains with different immune reactions.

Comparative immunofluorescence study with murine lepromas induced in C57BL/6NJcl (immunologically high responder) and CBA/N (low responder) mouse strains revealed that fibrin formation was associated with cell-mediated immune resistance against invasive bacilli. Histochemistry on paraffin sections further elucidated fibroblast proliferation and formation of collagen fibers following fibrin deposition only in murine lepromas with positive host reactions.

Animals↗
PubMed1983

Comparative study with two polar types of murine leprosy: an involvement of plasminogen activator and its possible regulating factor in the granulomatous tissue reaction.

Enzymatic activities in a saline-extractable fraction from two polar types of murine lepromas were investigated using pyroglutamyl-glycyl-arginine-p-nitroanilide and plasminogen-rich, as well as plasminogen-free, fibrin plates. An inhibitor activity for urokinase was also measured. C57BL/6NJcl (immunologically high responder strain) mice inoculated with 2 X 10(8) Mycobacterium lepraemurium developed a localized lepromatous lesion after 4 weeks. The tissue extracts obtained after 4-6 weeks exhibited inhibition for urokinase (8.8 IU/mg protein), but no enzymatic activity. After 8-11 weeks, when the lepromas showed an ulcerative change, prominent peptide hydrolytic activity (84.8 nmol/mg/protein/ min) was demonstrated. The fibrin plate assay confirmed that plasminogen activator is predominantly involved (26.4 IU/mg protein). The proteolytic activation was apparently correlated with discharge of purulent materials containing the bacilli and subsequent limitation of leproma development. However, similar modulation of the fibrinolytic enzyme-inhibitor system was not shown in CBA/N mice (immunologically low responders). The tissue extracts showed a low level of urokinase inhibitor activity (1.9 IU/mg protein), but no peptidolytic or plasminogen activator activity. Consequently, lepromas were developed progressively until 25 weeks after infection and dissemination from the lepromatous lesion took place thereafter. In comparison with histologic findings, which revealed accumulation of lymphocytes and mononuclear cells in the peripheral zone of lepromatous lesions in the C57BL/ 6NJcl, but not in the CBA/N mice, a controlling mechanism of plasminogen activator in tissue is assumed to be involved in the development of the granulomatous tissue reaction.

Animals↗
PubMed1983

Purification of calmodulin from bovine parotid gland.

Calmodulin was purified from bovine parotid gland. This calmodulin showed a single band upon sodium dodecyl sulfate polyacrylamide gel electrophoresis, and a characteristic decrease of the mobility on native gel in the presence of Ca2+. The parotid gland calmodulin activated also calmodulin-deficient cyclic nucleotide phosphodiesterase in a Ca2+-dependent fashion, and this activation was abolished by trifluoperazine, W-7 or chlorpromazine. These results may indicate clearly the existence of calmodulin in bovine parotid gland.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1983

Four distinct antigen systems on human thymus and T cells defined by monoclonal antibodies: immunohistological and immunochemical studies.

Human thymus and T cell antigens were identified by using four distinct monoclonal antibodies (MoAb), designated 2D5, 5B3, 7A5 and 9D4. 2D5 antibody reacted with most human thymocytes and a few peripheral lymphocytes as well as with a subpopulation (20%) of bone marrow cells, and precipitated a 45K molecular weight (mol. wt.) component from 125I-labelled thymus cell lysate. 7A5 antibody also reacted with the majority (80%) of thymocytes but neither with peripheral lymphocytes nor with bone marrow cells. The antigen detected by 7A5 was a glycoprotein consisting of 48K and 12K mol. wt. components, which were non-covalently associated with each other. 5B3 reacted with virtually all of human thymus and T cells but not with the majority of B cells and bone marrow cells. This reagent precipitated a 72K mol. wt. glycoprotein from thymus and T cells. An additional 65K mol. wt. glycoprotein was precipitated by 5B3 together with the 72K mol. wt. component, but with poor reproducibility. 9D4 antibody, on the other hand, reacted with a 200K mol. wt. component from thymus and T cells as well as 220K and 210K components from the non-T cell fraction of tonsil lymphocytes. Whereas antigens detected by 2D5 and 7A5 appeared to be highly expressed on cortical thymocytes, the antigen defined by 5B3 occurred much more abundantly on medullary thymocytes and peripheral T cells than on cortical thymocytes. Based on the data described above, it is suggested that 7A5, 5B3 and 9D4 MoAb recognize human homologues of mouse TL, Ly-1 and Ly-5 antigens, respectively, whereas 2D5 antibody seems to resemble OKT10, as described by others.

Antibodies, Monoclonal↗
PubMed1982

Lead poisoning in an art conservator.

A case of lead poisoning in a female art conservator is reported. The patient had experienced excessive lead exposure while restoring an antique Peruvian tapestry from the Chancay period (1000 to 1500 AD) using a powdered pigment (cinnabar), which had been recovered from the same tomb in which the tapestry was found. Over two months, prominent neurological, gastrointestinal, and diffuse muscular symptoms developed. Severe anemia accompanied by basophilic stippling of RBCs led to the diagnosis of lead poisoning, which was confirmed by markedly elevated blood lead levels (up to 130 micrograms/dL) and impairment of heme synthetic enzymes. The severity of the intoxication necessitated chelation therapy. Chemical analysis of the antique powdered pigment showed it to be the source of lead exposure, in that it contained about 1% lead.

Adult↗
PubMed1982

Surface antigenic phenotypes of human T-cell leukemia corresponding to those of post-thymic T cells.

Leukemic cells from eight adult patients with various types of T-cell leukemias, including one patient with lymphosarcoma cell leukemia (T-LSL), two patients with chronic lymphocytic leukemia (T-CLL), and five patients with adult T-cell leukemia (ATL), were analyzed for their surface antigenic phenotypes with a series of monoclonal antibodies directing to human T-cell differentiation antigens. All of the leukemic T cells studied were regarded as being of post-thymic T-cell origin because of their ability to form rosettes with sheep red cells under the condition at 4 degrees C but not 37 degrees C as well as the expression of human Ly-1-like but not TL-like antigen on their cell surfaces. By using monoclonal antibodies to a variety of human of three distinct categories. Thus, one patient with T-LSL had cells with Leu-1+2a+3a+ phenotype, which might reflect possible post-thymic precursor T cells, whereas one patient with T-CLL had cells with the same phenotype (Leu-1+2a+3a-) as normal cytotoxic/suppressor T cells. The latter cells also expressed Ia antigens as defined by monoclonal antihuman Ia antibody. The remaining six cases, including one T-CLL and five ATL patients had leukemic cells with the same phenotype (Leu-1+2a-3a+) as normally found on helper/inducer T cells, despite distinct clinical and immunological features between T-CLL and ATL. Some clinical findings observed in those patients may reflect functional activities retained by their leukemic T cells.

Antibodies, Monoclonal↗
PubMed1982

Assessment of lead health hazards in a body shop of an automobile assembly plant.

This study of an occupationally lead-exposed group in the automobile assembly industry (body shop employees) has provided information with regard to current and recent lead-exposure levels characteristic for these operations. Comparison with findings in other, previously studied occupational groups (secondary smelter workers) indicated that current and recent lead exposure was significantly lower in the autobody shop employees. Prevalence of symptoms was found to be higher than in a control, non-lead-exposed group of maintenance workers in the same plant, but the differences reached the level of statistical significance only sporadically. Long-term effects on renal function, as reflected in blood urea nitrogen (BUN) and creatinine levels, were documented to be significant in this group of autobody shop employees. When compared with two secondary lead smelter populations previously studied, correlations between indicators of renal function, BUN and creatinine, and duration of lead exposure were consistently higher in the secondary lead smelter populations than in the group of autobody shop employees, although duration of lead exposure was greater in the latter. These findings are consistent with a dose-response relationship with regard to renal function impairment due to lead absorption. An increased prevalence of hypertension, especially diastolic, was also found, probably the consequence of renal effect.

Adult↗
PubMed1982

Subjective symptoms in workers with low-level exposure to lead.

In an attempt to identify health effects associated with low-level lead exposure, 45 cable-manufacturing workers underwent clinical examinations in a cross-sectional study. Thirteen workers were in direct contact with lead-containing stabilizers, while 31 were only indirectly exposed. The directly exposed had a higher prevalence of reported neurological and gastrointestinal symptoms than those with low or insignificant lead exposure. None of the directly exposed had blood lead levels exceeding 60 micrograms per 100 ml. The clinical symptoms correlated with blood lead and zinc protoporphyrin. However, when the data were subjected to hierarchical log-linear modeling, a partial association was found between zinc protoporphyrin and symptoms, but not between blood lead and symptoms. The data suggest that non-specific neurological and gastrointestinal symptoms may occur at relatively low blood lead and zinc protoporphyrin levels, and that measurement of zinc protoporphyrin and exploration of clinical symptoms are valuable components in lead screening programs.

Adult↗
PubMed1981

Analysis of human T-cell antigens by one- and two-dimensional polyacrylamide gel electrophoresis.

One- and two-dimensional polyacrylamide gel electrophoresis (PAGE) was performed on immunoprecipitates formed between anti-human T-cell xeno-antiserum (ATS) and cell-surface glycoproteins of human lymphocytes, that had been radioiodinated by lactoperoxidase and purified on a Lentil lectin-coupled Sepharose 4B column. In some experiments, the cells were 3H-labeled by periodate-tritiated borohydride. ATS that was absorbed with B cells recognized a number of cell-surface antigens expressed preferentially on human thymus and T cells, with molecular weights of 150K (T150), 94K (T94), 72K (T72), and 65K (T65) daltons. Whereas T150 appeared to consist of multiple components of heavily sialylated glycoproteins and to be expressed largely on thymus and T cells, and to a much lesser extent on B cells, the remaining T94, T72, and T65 glycoproteins seemed to be present on thymus and T cells but absent from B cells. Two-dimensional PAGE analysis of these T-cell glycoproteins precipitated by ATS demonstrated that T94 was an acidic glycoprotein with pI of 4, while T72 and T65, the latter being found on thymus and T cells but not on T cell-type leukemic cells, exhibited marked electric charge heterogeneity with pI ranging from 4 to 7. These data clearly suggest that human thymus and T cells possess a complex antigenic make-up on their cell surfaces, comparable to that of mouse T cells with a variety of Ly antigen systems.

Antigens, Surface↗
PubMed1981

Immunochemical characterization of human TL-like (T48) and Ly 1-like (T72) glycoproteins using two-dimensional polyacrylamide gel electrophoresis.

Xenoantisera, designated AT48 and AT72, were developed by immunizing rabbits with human thymus cell membrane and guinea-pigs with a T-cell glycoprotein purified from leukaemic T-cell membrane. Whereas AT48, after appropriate absorption, reacted exclusively with the majority of thymocytes (mainly cortical thymocytes) among normal lymphoid populations, AT72 reacted with virtually all of the thymus and T cells but not with B cells. Thymocytes, which were strongly reactive with AT72, existed in the thymic medulla, but cortical cells were also very weakly reactive with AT72. When cultured T-cell lines, all of which were derived from patients with T-cell-type acute lymphatic leukaemias, were tested for their reactivities with AT48 and AT72 by immunofluorescence, we found that AT48 stained certain T-cell lines, whereas AT72 stained all of the T-cell lines tested so far. Immunochemical data showed that AT48 precipitated a 48K molecular weight (mol. wt) glycoprotein from 125I-labelled thymus cell surface glycoproteins, which appeared to be very weakly associated with a 12K mol. wt component. These 48K and 12K mol. wt components precipitated by AT48 showed almost identical isoelectric points (pI) to those of HLA heavy chain and beta 2-microglobulin respectively. AT72, on the other hand, precipitated a 72K mol. wt glycoprotein from thymus and T cells as well as from leukaemic T cells. A less prominent 65K mol. wt glycoprotein was also precipitated by AT72 from thymus and T cells but not from leukaemic T cells. These two components showed almost identical pI ranging approximately from 4 to 7, and this marked charge heterogeneity observed was reduced by neuraminidase treatment, suggesting that it reflects the heterogeneity in sialylation of this molecular species. We concluded from these data that AT48 and AT72 used in this work could detect human homologues of mouse TL and Ly 1 antigens respectively.

Antigens, Differentiation, T-Lymphocyte↗