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Biomedical subjects

D W Nitzan

Publications and source records attributed to D W Nitzan.

At least 19 recordsLinked to original sources
PubMed1992

Intra-articular pressure measurements in patients with suddenly developing, severely limited mouth opening.

A condition of sudden, severe, and persistent limited mouth opening, which readily responds to arthrocentesis, is postulated to be the effect of a vacuum between disc and fossa in the upper compartment of the temporomandibular joint. In 16 patients with this condition, the negative intra-articular pressure was found to be significantly lower (mean, -82.6 +/- 25.4 mm Hg) than in the control group (mean, -7.7 +/- 2.5 mm Hg) (P less than .0001). It is suggested that the process underlying the vacuum effect starts with persistent pressure (eg, clenching) resulting in the viscoelastic disc being pressed flat against the fossa. Immediately on cessation of the pressure, the disc resumes its natural biconcave shape, but its rims remain fastened to the fossa. The consequent increased negative pressure in the closed space created firmly anchors the disc to the fossa and any attempt to elicit condyle and disc sliding will only stretch the joint capsule and cause pain. This, in turn, will reflexly prevent the pterygoid muscle from exerting sufficient force to pull the disc and thus release the vacuum. This chain of events may account for the severe and persistent limitation in jaw movement and for the easy reversal of the condition by simple nonsurgical treatment.

Adolescent↗
PubMed1992

Severe limitation in mouth opening following transtemporal neurosurgical procedures: diagnosis, treatment, and prevention.

Five new patients and six previously described patients with severe limitation in maximum mouth opening following transtemporal neurosurgical procedures are described. Six patients underwent an operation for epidural hematoma and three for skull-base meningloma; two were treated with a pterional craniotomy for an aneurysm. Limited maximum mouth opening in these circumstances is caused by temporal muscle scarring and shortening. Aggressive physiotherapy is potentially beneficial if started early. If, however, diagnosis is delayed, the efficacy of physiotherapy declines, and surgical treatments such as temporal muscle detachment and coronoidectomy are fully indicated. The differential diagnosis, prevention, and treatment of limited maximum mouth opening following neurosurgical procedures are discussed.

Adult↗
PubMed1991

An alternative explanation for the genesis of closed-lock symptoms in the internal derangement process.

Clinical and surgical data on 194 operated joints (135 patients) were used to substantiate a new concept challenging the presumed natural history of temporomandibular internal derangement (ID). A number of findings were incompatible with the traditional depiction of a progressive process based on gradual changes in disc position and shape. These findings were a lack or correlation between increasing age and the stages of the process; the percentage of patients in the third stage (closed lock) with limited opening (less than 25 mm) too severe to be caused solely by a nonreducible, displaced disc; the unexpectedly high incidence (greater than 50%) of normally shaped discs in the third stage of the process. A specific condition of severe and stubborn limited maximal mouth opening caused by total cessation of gliding, liable to occur at any age and unrelated to disc shape or position, which responds successfully to simple treatment by lavage and lysis, pressured injection, or arthrocentesis, was discerned. Lack of gliding was attributed to adherence of the disc to the fossa by a reversible effect such as a vacuum and/or decreased volume of synovial fluid of high viscosity. This condition was deemed worthy of an independent identity, dissociated from disc displacement, as a causative factor in the second and third stages of ID, and particularly as an aid to accurate diagnosis and treatment.

Adolescent↗
PubMed1991

The value of arthrography in the decision-making process regarding surgery for internal derangement of the temporomandibular joint.

In this study, the clinical and arthrographic findings from 43 internally deranged temporomandibular joints (TMJs) were compared with the intra-surgical observations. In 40 of 43 joints, arthrography did not provide any additional information useful for diagnosis or treatment. In six joints, the problem was misdiagnosed. Only in three joints did arthrography demonstrate the existence of perforation in the posterior attachment that had not been suspected during the clinical examination. Because of the doubtful importance of arthrographic information for the decision-making process, it is suggested that the method be applied only in cases in which clinical examination and plain radiographs have failed to uncover the signs and symptoms indicative of a TMJ disorder.

Adolescent↗
PubMed1991

Condylar hyperplasia: remodeling of facial structures following condylectomy. Report of two cases.

Condylectomy accompanied by either simultaneous or postponed surgical correction of facial asymmetry is the treatment of choice in cases of condylar hyperplasia in its active stage. However, spontaneous remodeling processes in facial structures following the elimination of an actively growing hyperplastic condyle may bring about improvement in symmetry without further surgical intervention. Two cases are presented.

Adult↗
PubMed1990

Arthroscopic lavage and lysis of the temporomandibular joint: a change in perspective.

Arthroscopic surgery was applied to correct various disorders of the temporomandibular joint (TMJ). Lysis and lavage of the upper TMJ compartment proved of value in patients with anterior disc displacement without reduction ("closed lock"), because it increased the range of mouth motion and alleviated pain in the TMJ. Because this beneficial arthroscopic intervention did not encompass repositioning the disc, its surgical relocation when attempting to overcome dysfunction and pain in the TMJ is questioned.

Adult↗
PubMed1990

The use of monoclonal anti-CEA antibody immunohistochemistry in detecting the origin of oral cavity metastasis.

A 75-year-old woman presented with a painless swelling in the right mandibular retromolar area and numbness of the left lower lip. Radiographic examination of the mandible demonstrated an osteolytic lesion of the ascending ramus. Biopsy revealed adenocarcinoma of obscure origin. Staining of the specimen with a monoclonal antibody specific to colon carcinoma revealed its origin. On subsequent examinations, a primary tumor in the rectosigmoid region with extensive lung, liver and skeletal metastases were diagnosed. This unusual case of colonorectal carcinoma, presenting as a metastatic lesion of the mandible, was readily diagnosed by a novel immunohistochemical technique that utilizes highly specific monoclonal antibodies.

Adenocarcinoma↗
PubMed1989

Oncogenous osteomalacia: a case study.

A case of oncogenous osteomalacia due to a fibrosarcoma of the maxilla is reported, with a 19 year course before treatment. Metabolic studies of calcium and phosphorus were performed 3 and 19 years after the first symptomology. There was a negative balance for both phosphorus and calcium with low serum levels of 1,25-dihydroxyvitamin D which were corrected by resection of the tumor. Portions of the tumor were cultured and the supernatant did not affect phosphorus transport by a proximal tubule kidney cell line. Other portions were injected into athymic nude mice where they resulted in hypophosphatemia and phosphaturia, thus confirming the endocrine nature of the oncogenous osteomalacia factor.

Adult↗
PubMed1989

Temporomandibular joint fibrous ankylosis following orthognathic surgery: report of eight cases.

Undue pressure on the temporomandibular joint consequent to orthognathic surgery may result in fibrous ankylosis in the joint. Occurrence of this disorder may increase with the use of rigid internal fixation combined with 6 to 8 weeks of maxillomandibular fixation. Proper intraoperative placement of the proximal mandibular segment is the key to prevention of this complication, especially in high-risk joints.

Adolescent↗
PubMed1986

Suppression of chemotactic activity of human polymorphonuclears by monoclonal IgMs with and without biological activity.

The influence of monoclonal IgMs on migration of human polymorphonuclears was studied at various temperatures by the use of 19 sera with monoclonal IgMs from patients with macroglobulinemia of Waldenstrom (MW) without obvious biological activity, 29 sera with monoclonal IgM cold agglutinins (18 with anti-I and 11 with anti-i IgMs) and 3 sera with monoclonal IgM rheumatoid factor (RF). Under-agarose migration method and modified Boyden chamber method with double filters and 51Cr-PMNs were used. In under-agarose method, chemotactic differentials for controls, MW, anti-I, and anti-i groups were, respectively, 57 +/- 8 mm, 39 +/- 9 mm, 44 +/- 14 mm, and 32 +/- 16 mm at 37 degrees C and 47 +/- 18 mm, 22 +/- 11 mm, 17 +/- 9 mm, and 15 +/- 12 mm at 24 degrees C. All three sera with IgM RF inhibited chemotaxis. The differences between all groups and controls were significant at p less than 0.01. Random migration was inhibited at 24 degrees C (p less than 0.01) but not at 37 degrees C. Inhibitory concentrations of IgM in the sera tested were equal or less than 0.5 mg/ml. Thirteen sera were tested by the modified Boyden chamber method. At 37 degrees C 8 of 13 sera and at 24 degrees C 11 of 13 sera inhibited significantly chemotaxis at a concentration of IgM of 1 mg/ml. The lowest inhibitory concentration of IgM was 25 micrograms/ml. Eleven chromatographically pure IgMs were tested in the under-agarose assay. At concentrations of 0.4-3.7 mg/ml, eight IgMs inhibited chemotactic differential at 37 degrees C and nine inhibited it at 24 degrees C. At concentrations of 0.6-2.0 mg/ml, all seven pure IgMs tested by the Boyden chamber method significantly inhibited chemotaxis at 24 degrees C and 37 degrees C. Some IgMs inhibited chemotaxis at concentrations as low as 25 micrograms/ml. Ten IgM CA were eluted from the red blood cells. Eluates inhibited strongly chemotaxis at 24 degrees C and 37 degrees C. Heat inactivation did not alter inhibitory activity of IgM, however pepsin digestion or reduction and alkylation of purified IgMs did abolish their inhibitory activity. Inhibition of chemotaxis was not related to the light chain type, the titre, or the thermoamplitude of cold agglutination. However, monoclonal IgMs with anti-i cold agglutinin activity were stronger inhibitors than anti-I. Since 75% of IgMs tested inhibited chemotaxis at 37 degrees C, it is possible that monoclonal IgMs, especially those with anti-i cold agglutinin activity, inhibit PMN migration in vivo.

Agglutinins↗
PubMed1986

The effect of aging on tooth morphology: a study on impacted teeth.

The effect of age on dental tissues was studied on histologic sections of totally impacted teeth obtained from patients between 11 and 76 years of age. Impacted teeth were used in order to obviate the influence of the environmental effects prevalent in the oral cavity. The presence of concentric denticles and diffuse calcifications was determined, and the width of secondary dentin, predentin, and cementum was measured. The width of predentin and cementum increased linearly with age, whereas the aging process of secondary dentin formation and diffuse calcifications followed a different pattern. The incidence of concentric denticles was identical for all age groups.

Adolescent↗
PubMed1986

Inflammatory cells and bacteria in pericoronal exudates from acute pericoronitis.

The present work is one in a series of studies carried out to verify the relationship between bacteria and gingival tissues in pericoronitis. Exudates from 6 cases of acute pericoronitis were examined by light and electron microscopy, including ultrathin sections and negative staining. While bacterial phagocytosis was prevalent in all the exudates studied, spirochetes, which were the predominant microorganisms, were not observed being phagocytized by PMNs or macrophages. The presence of spirochetes in pericoronitis as compared with acute necrotizing ulcerative gingivitis is discussed.

Acute Disease↗
PubMed1985

Modulation of locomotor activity of polymorphonuclear cells by cationic substances and cationic lysosomal fractions from human neutrophils.

Seven cationic substances--human and egg-white lysozyme, RNase, protamine, histone, poly-L-lysine and poly-L-arginine; five cationic lysosomal fractions from human polymorphonuclears (PMNs); RNA; poly-L-glutamic acid; DNA; heparin; endotoxin; mastocytotropic agent compound 48/80; and cytochalasin B were tested for the influence on chemotaxis and random migration of human PMNs using under-agarose migration and Boyden chambers with two filters and [51Cr]PMNs. The above substances were either preincubated with PMNs, added to chemoattractants, or used instead of chemoattractants. In under-agarose migration method chemotaxis was inhibited by 11-35% when egg-white lysozyme, protamine, heparin, endotoxin, or compound 48/80 was added to the cells. High concentration of cytochalasin B inhibited chemotaxis by 73%. Cationic fractions I and V and low concentration of cytochalasin B enhanced chemotaxis by 11%, 41%, and 30%, respectively. When human and egg-white lysozyme, DNA, or cytochalasin B was added to the chemoattractants, motility of PMNs was inhibited. Cationic fractions II and V from human PMNs, when used as chemoattractants, enhanced cellular motility by 143-167%. Random migration was enhanced by heparin and inhibited by cytochalasin B and by cationic fractions from human PMNs. These findings suggest that various cationic and anionic substances and cationic fractions from human PMNs have heterogeneous influence on random migration and chemotactic activity of human PMN. Analysis relating chemotaxis to phagocytosis and to intracellular bactericidal activity (ICBA) has shown several patterns. Protamine, poly-L-lysine, poly-L-arginine, and agent compound 40/80 all inhibit chemotaxis and enhance phagocytosis and ICBA; cationic fractions II and V enhanced all three functions, whereas cytochalasin B suppressed phagocytosis and ICBA and had concentration-dependent modulatory influence on chemotaxis. It implies diverse mechanisms of action and possible impact on inflammatory reactions.

Chemotaxis↗
PubMed1985

Pericoronitis: a reappraisal of its clinical and microbiologic aspects.

Pericoronitis is an infectious disease of the operculum overlying an erupting or semi-impacted tooth. It manifests itself mainly in late adolescence and young adulthood and nearly always occurs around the lower third molar. The distinctive location, age, clinical picture, and link with predisposing factors warranted a reappraisal of pericoronitis and its etiology. Spirochetes and fusobacteria proved prevalent at all stages of the disease. The presence of these microbacteria may provide a clue as to the late appearance, particular location, and singular clinical picture of pericoronitis. The fact that spirochetes and fusobacteria are also found in acute necrotizing ulcerative gingivitis, and have been associated with alveolar osteitis, indicates a possible relationship between these disorders and pericoronitis.

Adolescent↗