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Biomedical subjects

L Silverstein

Publications and source records attributed to L Silverstein.

17 recordsLinked to original sources
PubMed2000

Periodontal probing: probe tip diameter.

BACKGROUND: Periodontal probing is one of the most common methods used in diagnosing periodontal disease. The purpose of this study was to determine the importance of the diameter of periodontal probing tips in diagnosing and evaluating periodontal disease. METHODS: The literature discussing periodontal probe diameters in human, dog, and monkey studies was reviewed and compared. Tip diameters varied from 0.4 to over 1.0 mm in these studies. Probe advancement between the gingiva and the tooth is determined by the pressure exerted on the gingival tissues and resistance from the healthy or inflamed tissue. The pressure is directly proportionate to the force on the probe and inversely proportionate to the probe tip diameter. The larger probing diameters reduced probe advancement into inflamed connective tissue. This effect of change in probe diameter reduced the pressure in a greater manner than an increase of similar change in probe force. RESULTS: In the studies reviewed, the pressure used to place the probe tip at the base of the periodontal sulcus/pocket was approximately 50 N/cm2 and at the base of the junctional epithelium, 200 N/cm2. A tip diameter of 0.6 mm was needed to reach the base of the pocket. Clinical inflammation did not necessarily reflect the severity of histological inflammation, and the recordings may not illustrate probing depth. Furthermore, probing depth did not identify anatomical locations at the base of the pocket. CONCLUSIONS: Probe tips need to have a diameter of 0.6 mm and a 0.20 gram force (50 N/cm2) to obtain a pressure which demonstrates approximate probing depth. This pressure was needed to measure the reduction of clinical probing depth, which included formation of a long junctional epithelium as a result of therapy. In addition, different forces or diameter tips are needed to measure healthy or inflamed histological periodontal probing depths.

Animals↗
PubMed1998

The key to success: maintaining the long-term health of implants.

During the infancy years of dental implantology, the emphasis for long-term success of osseointegrated implants was the surgical phase of dental implantology. In the years that followed, the emphasis for success had switched from a purely surgical influence to focusing more on the proper fixture placement which would be dictated by the prosthetic and aesthetic needs of each particular case. In more recent years, the dental profession has recognized professional implant maintenance and diligent patient home care as two critical factors for the long-term success of dental implants. The microbiota and clinical presentation of peri-implantitis is the same as periodontitis around a natural tooth.

Dental Implantation, Endosseous↗
PubMed1995

Cytokine secretion induced by superantigens in peripheral blood mononuclear cells, lamina propria lymphocytes, and intraepithelial lymphocytes.

Superantigens are potent inducers of T-cell proliferation and induce a broad range of cytokines, including tumor necrosis factor (TNF), gamma interferon, and interleukin 2 (IL-2). In the present study, we compared the abilities of different staphylococcal superantigens (staphylococcal enterotoxin B [SEB], staphylococcal enterotoxin E [SEE], and toxic shock syndrome toxin 1 [TSST-1]) to stimulate distinct cytokine profiles in peripheral blood mononuclear cells (PBMC), lamina propria lymphocytes (LPL), and intraepithelial lymphocytes (IEL). One million PBMC, LPL, and IEL were stimulated with various concentrations of superantigen (10 to 0.001 ng/ml) for 24, 48, and 72 h. Maximum cytokine production by PBMC, LPL, and IEL was observed for all three superantigens at 48 h at a concentration of 1 ng/ml. In PBMC, SEE and TSST-1 stimulated more IL-2 and gamma interferon than SEB. SEE and TSST-1 also stimulated more TNF and IL-4 production than SEB. In contrast, SEB stimulated more IL-6 than either SEE or TSST-1. In LPL, there was no SEE-induced IL-2 or IL-4 production, but IL-6, TNF, and gamma interferon were induced. SEB similarly induced no IL-2 or gamma interferon from the LPL, but IL-4, IL-6, and TNF were detected. TSST-1 stimulation of LPL resulted in IL-2 and TNF production but no IL-4, IL-6, or gamma interferon. In IEL, SEE induced no IL-2, IL-4, or gamma interferon but produced IL-6 and TNF, while SEB stimulation resulted in no IL-2 or gamma interferon but did result in detectable IL-4, IL-6, and TNF. Taken together, these data indicate that there are significant differences in the cytokine profiles induced by superantigens in LPL and IEL compared with those in PBMC, and these differences may relate to differences in activation requirements.

Bacterial Toxins↗
PubMed1994

Implant prosthodontic procedures for a completely edentulous patient with cleft palate.

Prosthodontic treatment of the edentulous cleft palate patient presents the dentist with numerous challenges for achieving a satisfactory result for the patient. A technique is described for prosthodontic rehabilitation of a completely edentulous cleft palate patient using bone augmentation procedures, root-form dental implants, and a removable maxillofacial prosthesis. Dental implants may improve prosthesis retention, stability, and occlusal function when used in carefully selected cases.

Adult↗
PubMed1992

Carcinoma of prostate in men aged fifty and under: therapeutic options.

We made a retrospective study of 20 men, aged fifty or under, with adenocarcinoma of the prostate to evaluate presenting symptoms, stage, grade, and therapeutic results. Sixty-five percent were found to have extracapsular spread of disease (Stage C or D). The therapy used was one or a combination of three types: radical prostatectomy, radiation therapy, and hormonal manipulation. Five of 6 patients with Stage B disease and 3 of 6 patients with Stage C disease were treated with radiation therapy. The other Stages B and C patients underwent radical prostatectomy. In all 5 of Stage B patients receiving radiation, therapy failed; the mean time to tumor recurrence was 3.2 years. Two of 3 patients with Stage C disease died of metastatic disease within three years of receiving radiation. The 4 patients (Stages B and C) who underwent radical prostatectomy are free of disease. There was a statistically higher failure rate among the radiation therapy patients with Stages B and C disease than among the surgical patients (X2 = 8.4, p less than 0.1).

Adenocarcinoma↗
PubMed1989

Lichenoid epidermal nevus: "linear lichen planus".

A 3-year-old girl had an eruption that showed clinical and histologic evidence of both a verrucous epidermal nevus and a lichenoid tissue reaction. Linear plaques had been present on her right lower limb for 2 years. Microscopic features included hyperkeratosis, papillomatosis, acanthosis, a bandlike lymphohistiocytic infiltrate that obscured the dermoepidermal junction, Civatte bodies, and melanophages. Lichenoid epidermal nevus is a new variant of linear verrucous epidermal nevus. At least some of the cases previously diagnosed as linear lichen planus probably represent lichenoid epidermal nevus. There is a parallel between lichenoid epidermal nevus and the entity described as inflammatory linear verrucous epidermal nevus, which frequently was misinterpreted as linear psoriasis before it was recognized as a linear verrucous epidermal nevus with psoriasiform features.

Child, Preschool↗
PubMed1988

Clinical and microbiologic effects of local tetracycline irrigation on periodontitis.

This investigation was conducted on seven individuals referred for treatment of moderate adult periodontitis. Twenty-eight sites with an average probing depth of 5.6 +/- 0.9 mm were evaluated. One tooth per jaw quadrant was randomly assigned to receive one of the following treatments: (I) no treatment, i.e., control; (II) saline irrigation; (III) tetracycline irrigation and (IV) scaling and root planing (SC/RP). A plaque control program was instituted one week prior to the experimental period and reinforced throughout the eight-week study. Irrigation was performed every 48 hours during the first two weeks of the experiment for Groups II and III, and the single treatment of SC/RP was carried out immediately following the baseline examination for Group IV. Clinical and microbiologic changes were monitored every two weeks using plaque and gingival indices, gingival fluid flow, probing depths, bleeding on probing and dark-field microscopic examination of the subgingival microbial flora. The tetracycline and SC/RP treatment modalities resulted in statistically significant clinical and microbiological improvements when compared with the control. Tetracycline irrigation alone and SC/RP alone had a similar effect in changing the subgingival microflora from one associated with disease to one associated with health. Thus, these treatment modalities are effective methods of producing statistically significant alterations in the subgingival microflora. The property of substantivity may contribute to the sustained duration of the effect of locally delivered tetracycline.

Adult↗
PubMed1987

Transformation of hairy cell leukemia to EBV genome-containing aggressive B cell lymphoma.

Hairy cell leukemia is a preplasmacytic B cell leukemia which is not EBV associated, although elevated titers of Epstein-Barr virus (EBV) antibodies have been seen in this leukemia and chronic lymphocytic leukemia. Hairy cells are not readily susceptible to EBV infection in vitro, even though they are EBV receptor-positive B cells. We have observed a 59-year-old patient who after 9 years of hairy cell leukemia developed a well-differentiated IgG-kappa monoclonal B cell lymphoma without further evidence of hairy cell leukemia. Pathologically, the lymphoma showed plasmacytic differentiation, and in the patient's serum, a 2 g/dl monoclonal IgG-kappa component was present. DNA extracted from the lymphomatous lymph node hybridized with DNA fragments of a reiterated sequence of EBV, IR1. The transformation, with no chemotherapy involved, from a preplasmacytic leukemia into a lymphoplasmacytic lymphoma with monoclonal gammopathy may be related to the entry of EBV into these cells. Studies at the molecular level may help understand mechanisms of malignant transformation or interconversion in lymphoproliferative disorders of the B cell type.

B-Lymphocytes↗
PubMed1985

Agarose-polyacrolein microsphere beads: a new microcarrier culturing system.

A new microcarrier (MC) culturing system for anchorage-dependent cells is described. The system is based on polyacrylein microspheres encapsulated in agarose and derivatized by various amino ligands. In practice, any protein or ligand with primary amino groups may be covalently bound to the microspheres through their aldehyde groups. The ease with which the beads may be derivatized enables the preparation of MC with desired surface properties for growing a variety of cells. In this model system the beads were derivatized by 2-(diethylamino)ethylamine (DEAE), diaminohexane (DAH), poly-L-lysine (PL), gelatin and collagen. The derivatized beads supported the growth of primary cells, diploid cell strains and established cell lines for biological studies as well as for production of various cell products.

Acrolein↗
PubMed1984

Vitamin-mineral supplement fails to improve IQ of mentally retarded young adults.

Twenty mentally retarded persons participated in a study to determine the effect of large doses of vitamin-mineral supplements on IQ, educability, electrophysiological responsiveness, and pyridoxine metabolism. Using a double-blind matched group experimental design, we administered supplements and placebos for 6 months. Pre- and postmeasurements showed no significant effects on any of the measured variables.

Adolescent↗
PubMed1968

Metacontrast and evoked potentials: a reappraisal.

Stimulation of the parafoveal retina may give rise to visual evoked responses generated in large part by stray light impinging upon the fovea. This effect appears to account for the absence of changes in the visual evoked response to parafoveal stimulation during metacontrast suppression. When the central retina is directly stimulated, the spatiotemporal interactions associated with brightness suppression during metacontrast may be readily demonstrated in a late component of the visual evoked response.

Evoked Potentials↗