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H Gendelman

Publications and source records attributed to H Gendelman.

At least 19 recordsLinked to original sources
PubMed2001

Loss of maternally derived human herpesvirus-6 immunity and natural infection in Argentinian infants.

BACKGROUND: Human herpesvirus-6 (HHV-6) infection is widespread throughout the world. No data are available in Argentina about the loss of maternally derived HHV-6 immunity and natural infection in infants. METHODS: A population of 100 pregnant women and 407 children between 1 and 15 months of age were assayed by indirect immunofluorescence to detect and quantify specific IgG anti-human herpesvirus-6 (anti-HHV-6) antibodies in Córdoba City, Argentina. RESULTS: There was no significant difference in the positive rate between infants aged 1 to 9 months (range, 43.6 35.5%) and pregnant women (37%). Seropositive ratio dropped in the 10-month group (23.33% seropositive) and rose sharply in the 11-month group (38.89%), 12-month (60.61%), and 13- to 15-month group (63.46%). The geometric mean titer (GMT) for infants in the 12 to 15 months age group (23.4 41.64) was significantly higher than the GMT for infants 10 months of age (11.04) (P < 0.05 with the Tukey-HSD test). CONCLUSIONS: This study shows a significant association between loss of passive HHV-6 antibody and age among infants. The results support evidence that HHV-6 enters the susceptible population at 11 months, leading to a high prevalence of antibodies in children between 13 and 15 months of age.

Adolescent↗
PubMed2001

Human papillomavirus infection in cyclosporin-induced gingival overgrowth in renal allograft recipients.

BACKGROUND: Host immunity plays an important role in the development of human papillomavirus (HPV)-associated disease. The HPV infection in oral cyclosporin-induced gingival overgrowth in renal transplant recipients has not been investigated previously. The aim of this study was to establish the HPV infection of cyclosporin-induced gingival hyperplasia in renal transplant recipients through morphological changes and use of the in situ hybridization technique. METHODS: We examined 13 renal transplant recipient biopsies with gingival overgrowth lesions and 4 healthy mucosa samples of these patients. The histopathological diagnoses were established on the basis of widely accepted criteria, and the pathologist was not aware of the HPV result. An in situ molecular hybridization was carried out under low stringent conditions to detect HPV species with mixed biotin-labeled probes of HPV 6 and HPV 11, and under high stringent conditions with HPV 6, HPV 11, HPV 16, and HPV 18 probes for HPV typing. RESULTS: The HPV prevalence among the 13 samples studied was 92.31% (12/13), of which 4 tested positive for HPV 6-11 and 1 for HPV 16. The 4 biopsies of normal mucosa from gingival overgrowth patients were also reactive for HPV DNA. In 11/12 (91.7%) HPV-positive cases, koilocytotic atypia was found. CONCLUSIONS: The suppression of T-cell function by cyclosporin therapy can result in an increase of HPV infection, adding to the proliferative activity of cyclosporin in the oral mucosa.

Adolescent↗
PubMed2000

[Morphology of the cells in myxoid tumors].

We describe a morphologic study of myxoid cells in myxoid tumors or with myxoid regions: myxoid fibrosarcoma, myxoma, myxoid liposarcoma, embryonal rhabdomyosarcoma, chondroma, chondrosarcoma, myxoid leiomyosarcoma, schwannoma, and odontoameloblastoma; and we compare with fibroblasts of umbilical cord, embryonal mesenquima and loose connective tissue in inflammatory conditions. Histologic techniques: H-E, PAS, Masson's trichrom, and Del Río Hortega's panoptic silver staining. Histologically Del Río Hortega's technique reveals bipolar fibroblasts with long processes. In myxoma and myxoid fibrosarcoma they are stellated with abundant processes and mucin cytoplasm secretion contained in bowls that slides through cytoplasmic expansions and discharge into intercellular space. The lipoblasts of myxoid liposarcoma are also stellated with abundant processes and contain drops of lipids. The rhabdomyoblasts are raquetoid cells with cross striated cytoplasm, myofibrils and cigar-shaped nuclei. Schwannomas are composed of spindle and bipolar cells with long and thin cytoplasmic extensions. The chondroblasts in chondromas and chondrosarcomas have wide cytoplasm with short processes. The odontoblasts in odontoameloblastomas have wide cytoplasm and long processes directly extended toward adjacent dentinal. These morphologic details can help in the differential diagnosis associated with immunoperoxidase stains.

Adolescent↗
PubMed2000

Enlargement of periosteocytic lacunae associated to mechanical forces.

Demineralization of bone has been linked to the action of osteocytes via the process of osteocytic osteolysis. The aim of this study was to assess the influence of mechanical forces produced during orthodontic movements on the osteocytic lacunae. Orthodontic movements were achieved employing a device constructed "ad hoc" for rats that exerts a force of approximately 70 gr. The experimental animals and the corresponding controls were killed 48 and 96 hours after the onset of the experiment. Histologic sections oriented along the bucco-palatine axis were employed to measure the area of osteocytic lacunae to infer information on volume in keeping with standard stereological concepts. Regions alongside resorption areas of cortical bone and resting areas of palatine bone were evaluated. Osteocytic lacunae associated to erosive surfaces were rounded and rose markedly in area after the application of the orthodontic force (58.4 +/- 6 mm2). Elongated lacunae were present in relation to resting areas (24.8 +/- 2 mm2). The present study shows an association between the increase in size of osteocytic lacunae and the resorption fronts induced by the application of orthodontic forces. This finding would suggest that the osteocyte would participate in the resorption process of bone submitted to pressure.

Alveolar Bone Loss↗
PubMed1999

[Human papillomavirus detection in oral cancer lesions in the city of Córdoba].

Oral cancer is a process that involves different etiological factors and mechanisms in the light of current view of viral cocarcinogenesis. Evidence from histology and DNA hybridization studies suggests that HPV is engaged in oral carcinogenesis. The Pathology Laboratory of the Dentistry School, National University of Córdoba, admits approximately 20% of all patients with cancerous lesions in this city. In the January 1992-December 1997 lapse, we examined 1950 biopsies with oral lesions, 4.77% (93/1950) of which were malignant neoplasms, 79.57% (74/93) were oral carcinomas. Thirty-three oral carcinomas (44.6%; 33/74) were selected at random and included in this study, 33 cells smears of normal oral mucosa of controls individuals were included. They were analyzed by conventional light microscopy and an in situ hybridization technique for the detection of HPV. Data were analyzed with chi square test. The prevalence of HPV among the 33 cancer samples studied was 27.27%, 9/33 tested positive for HPV in low stringent conditions. Only one was positive in high stringent condition for HPV16, a verrugous carcinoma. No HPV-DNA was detected in cells smears of controls. Among the HPV positive, 3/9 (33.33%) were squamous carcinomas and 5/9 (55.56%) were verrugous carcinomas. Only one was a melanoma. Verrugous carcinoma was the carcinoma most associated with the HPV infection (x2 = 20.5; 95% level of confidence). This would indicate a major role of HPV in the pathogenesis of verrucous carcinomas. The viral prevalence found in cancerous lesions reinforces the concept of heterogenic natures of oral cancer. HPV is a circumstance that increase the probability of malignancy, and when reducing, diminish the frequency of cancer.

Argentina↗
PubMed1997

Comparative study of AgNOR and PCNA in experimental carcinogenesis of salivary glands of rats.

Previous studies regarding experimental carcinogenesis demonstrated that submaxillar glands (GSM) submitted to DMBA present cellular modifications of progressive gravity in different periods after eight days of the experiment (J. Dent. Res 59: 1067, 1980). This current work pursues the objective of determining, quantitatively, regions of nucleolar organizations (AgNOR) and immunomarkation of the antigen of nuclear proliferation (PCNA) for their possible link with the morphostructural findings previously described. By means of argentic impregnation, the AgNOR were identified. The histometric was performed according to the numeric parameters of AgNOR per nucleus (CABRINI et al. 1992) immersed 1000x. A triple blind reading of the five randomly chosen studies from each of the twenty cases studies with distinct experimentation stages was completed. The results were compared to the normal areas (control group). The PCNA was determined immunohistochemically (Avidina-Biotina System Dako). The average number of AgNOR was 11 after eight days; 16 after fifteen days and 12 after twenty days of the experiment (100% adenocarcinoma). In the control group, the average number of AgNOR did not exceed 6. The PCNA after eight days was negative. The reaction in the tumor area was between 20 and 30% positive. The results indicate an increase in the number of AgNOR in relation to the neoplastic proliferation, corroborated by PCNA immunodetection.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1996

Study of the vascular pattern in oral lichen planus.

Oral Lichen Planus is a relatively frequent disease. Its etiopathogenesis is still unknown and it can undergo malignant transformation during its evolution. Thus, data which could contribute to the knowledge of the biology of this disease are particularly significant. The present study involves a quantitative evaluation of the vascular pattern of oral lichen planus. A portion of biopsy specimens taken for histopathologic diagnosis was processed to mark vascular walls using the histoenzymic technique for ATPase activity demonstration. Stained Sections were then evaluated in a semi-automatic magnetic image analyser. The stereologic parameters studied, showed there is no vascular increase in lichen with regard to normal mucosae or leukoplakias, since the number of vascular walls did not show significant differences. Instead, a significant increase was observed in the vascular area. The association of these parameters, indicates that lichen is a more congestive lesion than the other two conditions studied. These findings indicate that the modifications of the vascular pattern could play a role in the etiopathogenesis of oral lichen planus and suggest that the observation of these changes could be a useful element in the histopathologic diagnosis.

Adult↗
PubMed1994

Effect of dowel space preparation on the apical seal of root canal fillings.

The effect of post preparation on the apical seal was studied using simulated root canals. The maximum level of removal was tested with residual fillings 1, 2, 3, and 4 mm long. All of the artificial canals were filled with gutta-percha, Grossman's sealer, and lateral condensation. The removal was immediate and carried out with warm pluggers and the dowel space was completed with a Peeso drill. Stainless steel posts were cemented with zinc phosphate cement in the free space of the root canals. The coronal access of the canals was sealed with temporary fillings. After setting the materials, the specimens were immersed in a 2% methylene blue dye solution for 72 h and were observed with a measuring microscope. The final length of the apical fillings was found to be different from the intended length in every group. As far as leakage was concerned, 1, 2, and 3 mm-long fillings did not show a significant difference when compared with the negative control group (that is to say, filled canals where no dowel space was created). In the 4 mm fillings the leakage value was zero. These findings may be of clinical importance when restoring short roots.

Dental Leakage↗
PubMed1993

Ameloblastic odontosarcoma: report of a case.

Ameloblastic odontosarcoma is an extremely rare malignant odontogenic tumor. To date only 8 cases have been reported in the literature. The case of a 12-year-old Hispanic-American boy with ameloblastic odontosarcoma of the mandible is presented. The patient had a tumor diagnosed previously as benign ameloblastic fibroma that underwent transformation to ameloblastic odontosarcoma. The patient has been followed for 19 years since the surgical removal of the tumor. Radiographic and clinical examination confirm that there is no evidence of recurrence. Periodic examination for the reappearance of the tumor will be continued.

Child↗
PubMed1993

Neodymium-YAG and CO2 lasers in treatment of pre-cancerous lesions of the oral cavity.

The oral mucosa is an area of premalignant lesions such as leukoplakias and lichens. This work analyzes results obtained from patients who are carriers of these premalignant lesions treated with 1,060 and 1,320 nm Nd-YAG and CO2 lasers. Certain immediate and mediate post-op symptoms such as pain edema, hemorrhage, recidivism and scar fibrosis were studied and favorable results were obtained with this therapy.

Adult↗
PubMed1991

[Incipient cariogenic demineralization of human enamel].

32 teeth (12 premolars and 20 molars) were studied under light microscopy, polarized microscopy, transparence light microscopy and scanning electron microscopy. These teeth presented changes in colour in their free and proximal surface as well as close to pits and fissures. As an extra diagnostic test the PAS reaction was used to assess descalcifying processes in both light and transparence microscopy. Polarized light was used to assess normal enamel. Scanning electron microscopy corroborated the lesions produced in the enamel surface in the form of micropores. PAS reaction diagnosed decalcifying processes in yellow, brown and brownish stains. White staims not always were PAS-positive and when they reacted in the same manner as other positive stains, with the immersion technique. This penetrated 40-60 umtrs. and in some areas in relation to lamellae they reached dentin. Light, polarized and scanning electron microscopy showed the presence of micropores in the external surface of enamel in PAS-positive cases. The possibility of a modified PAS technique to use in clinical practice is discussed. It is concluded that PAS relation is useful as "ex situ" test to detect the first signs of mineral salt loss at the enamel surface. More research is needed to transfer these results to clinical practice.

Bicuspid↗
PubMed1980

Histochemistry of glycoconjugates of pleomorphic adenomas of minor salivary glands, with special reference to glycocalyx of tubular areas.

Histochemical characterization of glycoconjugates elaborated by palatal pleomorphic adenomas showed that glycoproteins, glycosaminoglycans, and perhaps glycolipids were present in both the "epithelial" and "connective tissue" components of these tumors, as well as in the distinct glycocalyx present in the luminal surface of tubular and cystic areas.

Adenoma, Pleomorphic↗