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Biomedical subjects

M Gornitsky

Publications and source records attributed to M Gornitsky.

At least 19 recordsLinked to original sources
PubMed2002

A case-control study of temporomandibular disorders: symptomatic disc displacement.

This case-control study was designed to investigate the risk factors for disc displacement (DD) without myofascial pain (MFP). The study population included 59 cases with DD without MFP, selected in two hospital dental clinics, and 100 concurrent controls selected in one of these clinics. The association with DD was evaluated for bruxism, head-neck trauma, orthodontic treatment, and sociodemographic characteristics by using unconditional logistic regression. In the multivariate analysis, excluding psychological factors, an association was found between DD and clenching-grinding (OR=3.57; 95% CI: 1.27-9.98). This association persisted when anxiety (OR=3.07; 95% CI: 1.08-8.70) or depression (OR=4.02; 95% CI: 1.43-11.31) was included in the model. A positive association was noted between orthodontic treatment and DD (OR=3.10; 95% CI: 1.06-9.65). The effect between orthodontic treatment and DD remained and increased with the inclusion of anxiety (OR=3.65; 95% CI: 1.15-11.61) or depression (OR=3.20; 95% CI: 1.06-9.65). A high level of anxiety (OR=2.40; 95% CI: 1.01-5.73), was positively related to DD. We concluded that clenching combined with grinding, and orthodontic treatment are factors related to DD. The interpretation of these associations, however, requires caution because of the inclusion of prevalent cases.

Adolescent↗
PubMed2002

Heterogeneity of temporomandibular disorders: cluster and case-control analyses.

Cluster analysis has been applied to the classification of temporomandibular disorders (TMD). The factors most often used in these classification systems are psychological and psychosocial. The aim of this study is to classify individuals diagnosed with TMD, by using cluster analysis based on their clinical condition and the global severity of the disease. In this study, one investigator selected the patients at the dental clinics located at the Jewish General and Montreal General hospitals, Montreal, Canada, from September 1994 to December 1997. The study population included 162 outpatients. The results of this study indicated the existence of four TMD subgroups: three TMD pain groups with localized or generalized disorder related to different levels of interferences in their life and a non-pain, but disabled group. External validation of the cluster solution support the replication of the four groups and allow for further interpretation of the patients' profiles. Clenching-grinding and depression were related to the groups presenting generalized TMD. Orthodontic treatment and female sex, however, were the factors associated with a more localized condition. This classification system may provide a better understanding of the TMD subgroups and clues for the treatment and prognosis of TMD patients.

Adolescent↗
PubMed1998

Mercuric chloride induces a stress response in cultured astrocytes characterized by mitochondrial uptake of iron.

Mercury exerts a variety of toxic effects on both neurons and glia. Mercury induces aberrations in microtubules, ion channels and mitochondria presumably by binding to sulfhydryl groups. Indirect evidence further suggests that mercury targeted to mitochondria may induce iron-catalyzed oxygen radical production. We have previously shown that the mitochondria of astrocytes subjected to oxidative stress accumulate redox active transition metals that may catalyze the formation of cytotoxic oxygen free radicals. In the present study we have investigated the effect of mercuric chloride on astrocytes in monolayer culture in order to determine whether mercury accumulates in astrocytic mitochondria and whether mercury exposure triggers a stress response-associated uptake of iron. Our results indicate that mercuric chloride exposure initiates the constellation of changes in mitochondrial structure that typifies the response of these cells to oxidative stress. Energy dispersive Xray microspectroscopy demonstrates that these altered mitochondria concentrate both mercury and iron. Concurrent with these changes, mercuric chloride treatment activates transcription of the heme oxygenase-1 (HO-1) gene in a dose dependent manner, further indicating an oxidative stress response. Thus, mercury-induced stress may transform innocuous astrocytes into potentially lethal sources of cytotoxic oxygen free radicals.

Animals↗
PubMed1996

Oral stent as treatment adjunct for oral submucous fibrosis.

Oral submucous fibrosis is a chronic inflammatory disease that results in progressive juxtaepithelial fibrosis of the oral soft tissues that can cause increasing difficulty in chewing, swallowing, speaking, and mouth opening. Many treatment regimens for oral submucous fibrosis have been proposed to alleviate the signs and symptoms of the disorder. In severe cases, surgical intervention is the only treatment modality, but relapse is a major problem. This article describes the use of an oral stent as an adjunct to surgery to prevent relapse.

Deglutition↗
PubMed1996

Candidal infection of the tongue together with candidal infection of the palate in patients with the human immunodeficiency virus.

The most common oral opportunistic infection affecting persons with acquired immunodeficiency is candidiasis. This article reports on candidal infection of the tongue together with candidal infection of the palate in patients who have the human immunodeficiency virus. A retrospective analysis of 336 patients with acquired immunodeficiency syndrome revealed a prevalence of 8% with candidal infection of both the tongue and palate. Patients in this group were significantly older (39.2 years versus 34.5 years) and had significantly lower CD4-CD8 ratios than did the rest of the cohort.

AIDS-Related Opportunistic Infections↗
PubMed1996

Fourth molars: a clinical study.

Supernumerary teeth may be found in both the primary and permanent dentition, although they are more common in the permanent dentition. Presence of a fourth molar is rare, and such a tooth is almost invariably impacted. Dental practitioners should be aware of the possibility of encountering this rare supernumerary, its diagnosis and treatment. The authors of this article conducted a survey of patients in Montreal, looking specifically at the prevalence, aetiology, diagnosis, pathology and treatment of fourth molars. Their findings are reported here, and compared with data from the literature over the past 15 years.

Adolescent↗
PubMed1995

The use of implants for orthodontic correction of an open bite.

This case illustrates the integration of maxillofacial surgery, orthodontics, prosthodontics and periodontics in the treatment of an adult male. A traumatic injury to the lower jaw was the stimulus for the patient to seek orthodontic correction of a severe malocclusion including crossbites and an anterior open bite. The loss of a large portion of the anterior alveolar process of the lower jaw including six teeth was corrected with an implant bearing prosthesis which was subsequently used as anchorage to correct the malocclusion. Through the combined efforts of the above disciplines, properly orchestrated, this patient was treated in an effective and successful manner.

Adult↗
PubMed1995

Nifedipine-induced gingival hyperplasia. A comprehensive review and analysis.

A comprehensive review of the literature and analysis of the clinical history, mechanisms, pathogenesis, histology, and management of nifedipine-induced gingival hyperplasia is reported. A correlation to age, gender, drug, dosage, duration of drug therapy, location, and mode of treatment is discussed. The case report presented provides a model for management of nifedipine-induced gingival hyperplasia and other drug-induced gingival hyperplasia.

Calcium↗
PubMed1994

Tongue, primary amyloidosis, and multiple myeloma.

A case of macroglossia and resulting apertognathia because of primary amyloidosis in a 65-year-old man with multiple myeloma is described. In addition, a retrospective study of the oral manifestations of primary amyloidosis and multiple myeloma in the last 15 years is reported.

Aged↗
PubMed1994

Interleukin-2-inducible natural immune (lymphokine-activated killer cell) responses as a functional correlate of progression to AIDS.

The functions of natural killer (NK) cells and their interleukin-2-deducible counterparts, lymphokine-activated killer (LAK) cells, are often impaired in human immunodeficiency virus (HIV)-infected individuals. A statistical approach was used to establish if changes in LAK activity were associated with antiviral drug therapy, HIV-1 burden, or lymphocyte subset alterations. Our study group included 61 HIV-positive subjects without any opportunistic infections (OI-), 16 of whom received zidovudine (AZT), and 97 HIV-positive individuals with AIDS-related infection (OI+), 50 of whom received AZT. As expected, there was a stepwise decrease in total lymphocyte numbers in OI+ groups as a result of the selective loss of CD4+ cells. The groups receiving AZT therapy had fewer CD4+ cells but lower circulating p24 antigen levels than corresponding untreated groups did. No significant changes in the relative proportions or absolute numbers of CD56+ subsets in HIV-positive groups could be ascribed to OI status or AZT intervention. LAK cell cytotoxic responses, measured as LU20 values (which give a measure of 20% cytolysis of target cells), lysis per unit CD56+ NK cell, or lysis per unit blood volume, declined in OI+ groups. No main or interactive effects of AZT therapy on LAK activities were observed. Multivariate general linear models were used to determine the interactive effects of NK- and T-cell subsets on measured LAK cell numbers were added negative and positive predictors of LAK activity, respectively. These findings indicate that declines in NK-mediated LAK cell responses serve as functional correlates of progression in HIV-infected individuals.

AIDS-Related Opportunistic Infections↗
PubMed1993

Changes in natural immunity during the course of HIV-1 infection.

The role of natural killer (NK) and lymphokine-activated killer (LAK) cell-mediated cytotoxicity in AIDS has yet to be established. The objective of this study was to determine inducible LAK cell responses at different stages of HIV-1 infection, and specifically to establish the participation of CD8 lymphocytes in these responses. Peripheral blood lymphocytes (PBL) were isolated from healthy seronegative (CDC-0) subjects and HIV-1+ individuals who were clinically asymptomatic (Centre for Disease Control group 2, CDC-2) or symptomatic (CDC-4) with regard to secondary opportunistic infection (OI). LAK cells were generated upon incubation of PBL with IL-2 and their cytolysis of K562 and U-937 targets was determined using chromium release assays. The role of CD8+ lymphocytes as progenitors and effectors of these LAK cell responses was determined by immunomagnetic depletion of CD8+ cells from precursor PBL and LAK cells, respectively. LAK cell-mediated cytotoxicities in HIV-1-infected individuals were reduced compared with seronegative controls without any corresponding changes in the relative proportions of CD56+ (NK) cells among groups. Depletions of CD8+ subsets from either PBL or LAK cells dramatically reduced total LAK cytotoxic responses and LAK activities per unit CD56+ cell in the OI-/CDC-2 seropositive population. No corresponding changes in LAK activities in seronegative control or HIV+/OI+/CDC-4 groups were observed. Levels of LAK activity against K562 targets in CDC-0/HIV- and CDC-4/HIV+ groups correlated with the percentage of CD56+ LAK cells; corresponding LAK activity in the CDC-2/HIV+ group correlated with the percentage of both CD56+ and CD8+ subsets. These findings suggest that adaptive changes in non-MHC restricted cytotoxic responses occur in HIV-1 individuals at early stages post-HIV infection, before the onset of opportunistic infection.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Increased LAK activity against HIV-infected cell lines in HIV-1+ individuals.

The role of natural killer (NK) cells and their inducible counterparts, lymphokine-activated killer (LAK) cells in AIDS with regard to HIV-1 viral immunosurveillance and the control of secondary opportunistic disease has yet to be established. In this study, we have demonstrated that LAK cells derived from all HIV-1+ groups showed striking increases in their capacity to lyse HIV-1-infected U-937 cells relative to their uninfected U-937 counterparts. Surprisingly, similarly derived LAK cells from healthy seronegative controls showed no differences in their lysis of HIV-1-infected versus uninfected U-937 cells. The differential ability of LAK effectors from seropositive donors to lyse HIV-1-infected targets was demonstrable using a number of U-937 subclones and their HIV-1-infected counterparts. Again, no differences in LAK cell-mediated lysis of HIV-1-infected and uninfected U-937 subclones were observed in seronegative individuals. Our findings that HIV-1+ individuals show selective expansion of non-MHC restricted, HIV-1-directed cytotoxic LAK cells indicate that natural immunity may indeed play a role in HIV-1 viral immunosurveillance.

Antigens, CD↗
PubMed1991

Clinical documentation and occurrence of putative periodontopathic bacteria in human immunodeficiency virus-associated periodontal disease.

Human immunodeficiency virus (HIV)-associated gingivitis (HIV-G) and HIV-associated periodontitis (HIV-P) are two intraoral lesions manifested by patients with HIV infection. Periodontal indices were measured for 87 subjects in 5 study groups: HIV-seropositive patients with healthy periodontium (HIV-H), with HIV-G, or with HIV-P; and non-HIV-infected subjects with healthy periodontium (H) or with adult chronic periodontitis (P). The quantitative clinical parameters were compared and statistically significant intergroup differences were noted. The mean scores on PI and PD do not discriminate between HIV-seropositive and non-HIV-infected seronegative cohorts, but a significant difference in the GI between HIV-H and H was noted. When categories of PD and AL are examined, some differences become apparent. Generally, the PD and AL of HIV-P are not as great as those of P. PI correlates well with GI (r = 0.86) in P, but does not (r = 0.33) in HIV-P. In addition, the occurrence of selected putative periodontopathic bacteria (Porphyromonas gingivalis, spirochetes, and motile eubacteria) in these lesions was determined by brightfield (after staining), darkfield and immunofluorescent microscopy. No difference in microbiological profile in the bacterial groups monitored was found between P and HIV-P. Spirochetes were found to be more abundant than P. gingivalis in the lesions of P and HIV-P. In marked contrast, P. gingivalis was found to be in highest numbers in samples from the gingival crevice of H as determined by indirect immunofluorescence.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Benign mucous membrane pemphigoid: a case report.

A relatively rare systemic disease, benign mucous membrane pemphigoid (cicatricial pemphigoid) usually starts in the mouth and is clinically characterized by bullae that rupture and form an ulcer. A distinctive Nikolsky's sign is apparent using gentle air blasts or finger pressure. The pharynx, larynx, nose, esophagus, genitals and eyes can also be affected. Involvement of the conjunctivae can lead to scarring and ensuing blindness. The following case of a healthy 77-year-old man, diagnosed as suffering from mucous membrane pemphigoid, is of particular interest since several confusing clinical observations, including poor oral hygiene, the possibility of a contact dermatitis or an adverse antibiotic reaction, made the diagnosis more difficult. A careful medical history, examination and consultation process is paramount to initiating proper treatment and subsequent relief of symptoms. Benign mucous membrane pemphigoid must always be considered in any patient with desquamative epithelium of the oral mucosa.

Aged↗
PubMed1990

Resistance to infection by HIV-1 of peripheral blood mononuclear cells from HIV-1-infected patients is probably mediated by neutralizing antibodies.

We have investigated whether PBMC of HIV-1-seropositive subjects are as susceptible to in vitro infection by HIV-1 as are PBMC from seronegative controls. Accordingly, stimulated PBMC from 19 HIV-1-infected subjects were inoculated with four different variants of HIV-1. None of these cultures produced either detectable quantities of viral reverse transcriptase activity or p24 Ag following inoculation with HIV-1. In contrast, in five of six cases in which these PBMC were depleted of B cells by antibody plus complement prior to viral inoculation, the presence of viral reverse transcriptase and p24 Ag was detected. The presence of normal levels of CD4-Ag at the surface of the CD4+ cells in these populations was established by flow cytometry. Analysis by an immunoblot assay revealed that anti-HIV antibodies were present in the sera obtained from these infected donors; in addition, 7 of 10 culture fluids derived from the nondepleted PBMC were shown to contain virus-neutralizing antibodies. Cultures which were depleted of B cells did not contain detectable levels of antiviral antibodies. Confirmation that the virus produced by the PBMC which had been depleted of B cells was of the strain used to infect the cultures, rather than that which initially caused patient infection, was provided on the basis of differential susceptibility to antibody neutralization. These results suggest that antibodies produced by B cells in cultures of PBMC from seropositive donors may restrict infection by HIV-1 of such cultures under laboratory conditions.

Adult↗
PubMed1990

Diminution of inducible lymphokine-activated killer cell activity in individuals with AIDS-related disorders.

We have compared the relative ability of lymphokine-activated killer (LAK) cells derived from peripheral blood of HIV-seropositive people, AIDS subjects, and healthy controls, to lyse a panel of natural killer (NK)-sensitive and NK-resistant tumor and virally-infected targets. We have found that LAK cells derived from HIV-seropositive populations show a significant, albeit reduced, capacity to lyse U937, K562, and RAJI target cell lines, in comparison with similarly derived cells from healthy controls. The reductions in LAK activity in both HIV-seropositive asymptomatic and AIDS populations reflect a significant reduction in cytotoxic potential of individual LAK cells. The maximal LAK cytotoxic potentials of control, asymptomatic seropositive, and AIDS populations are comparable. LAK cells derived from HIV-seropositive populations show an enhanced capacity to lyse HIV-infected U937 targets relative to their uninfected counterparts. These enhancements in HIV-infected U937 versus U937 cytolysis arise from increases in the maximal cell-mediated cytolytic plateau. Depletion of NK (CD56+) lymphocytes from peripheral blood prior to LAK cell generation markedly diminishes subsequent specific and total inducible LAK activity. In some subjects, peripheral blood T-cell depletion prior to LAK cell generation results in LAK cells that are subsequently enriched for cytolytic activity, whereas in other subjects similar T-cell depletion impairs inducible LAK cell responses.

Acquired Immunodeficiency Syndrome↗
PubMed1989

Active replication of human immunodeficiency virus type 1 by peripheral blood mononuclear cells following coincubation with herpes viruses.

Patients with acquired immunodeficiency syndrome (AIDS) commonly suffer from opportunistic infections associated with members of the herpes virus family. To investigate whether certain of these other viruses might have an effect on the ability of the human immunodeficiency virus type 1 (HIV-1) to replicate, we coincubated peripheral blood mononuclear cells (PBMC) from nine HIV-1-seropositive donors with live preparations of various herpes viruses. In seven of nine cases, exposure of PBMC to preparations of either HSV-1, HSV-2, or CMV stimulated the cells to become active producers of HIV-1, as determined by reverse transcriptase activity and by the presence of infectious progeny virus. This increased production of HIV-1 particles appeared to be a consequence of mitogenic proliferation and of herpes virus-encoded transacting factors. These results supplement earlier findings on the molecular activation of the HIV-1 genome by both HSV and CMV genetic elements and point to a possible role for these viruses in the pathogenesis and ultimate clinical outcome of HIV-1 infections.

Adult↗