Biomedical subjects

Rumelia Koren

Publications and source records attributed to Rumelia Koren.

26 records · Page 2Linked to original sources

PubMed2002

Periappendiceal actinomycosis mimicking malignancy report of a case.

A case of a periappendiceal actinomycosis, seen in an 83-year-old woman, clinically mimicking a right ovarian neoplasm penetrating the right colon, is presented. The patient's complaints led to the discovery of a right abdominal mass. Explorative laparotomy and right hemicolectomy were done. Histological examination revealed periappendiceal actinomycotic abscesses. We discuss a possible pathogenesis and the therapeutic modalities.

Abscess↗

PubMed2002

The spectrum of laryngeal neoplasia: the pathologist's view.

Several types of neoplastic change with different prognostic implications typically involve the laryngeal squamous epithelium. The purpose of this review is to examine the spectrum of these changes, as well as their relationship to benign squamous epithelial proliferative states. Since these pathological changes are apt to occur in regions where the epithelial lining is typically squamous, it is important to recognize that the epithelium of the larynx varies from stratified squamous to respiratory-type, depending on the location. The lingual (anterior) surface of the epiglottis is lined by a stratified squamous type, while the laryngeal (posterior) surface is stratified squamous merging into respiratory-type. In the larynx, the supraglottic and infraglottic portions are a respiratory-type, which contrasts with the stratified squamous epithelium of the glottis. This typical distribution does show some degree of variability in those patches of squamous epithelium and is frequently seen within the respiratory-type epithelial regions. The junction between the two epithelial types may be abrupt or separated by a transitional zone.

Carcinoma in Situ↗

PubMed2002

Histological and scanning electron microscope examination of root canal after preparation with Er:YAG laser microprobe: a preliminary in vitro study.

OBJECTIVE: Until now, there has been no study that demonstrates the effectiveness of Er:YAG laser microprobes to clean and shape the root canal without using any mechanical instrumentation. MATERIALS AND METHODS: The study was conducted on 28 single-rooted extracted central incisors teeth with straight roots. Fourteen were mechanically prepared and served as the control group, and 14 were treated by Er:YAG laser only. From every group, half of the teeth were examined histiolgically and half by SEM. The instrument tested was an Er:YAG laser with microprobes 200-400 micro in diameter and 20 mm in length, coupled onto special handpieces, attached to the delivery fiber of an OPUS 20 Er:YAG laser. The Er:YAG laser was applied with the following parameters: wavelength 2.94 microm; pulse duration 400 msec; repetition rate 10 Hz; energy per pulse 140 mJ for the 400 micro microprobe and 90 mJ for the 200-micro microprobe. RESULTS: For the control group, histologically, large amounts of residual pulp tissue were found in the root canal cavity, and open tubules were seen in all the specimens; SEM examination showed very uniform root canal, from apical to cervical portion, high number of open tubules, and different levels of canal debridment. For the study group, histologically, no residual pulp tissue was found in the root canal cavity and open tubules were seen in all the specimens; SEM examination showed the root canal free of debris, removed smear layer, open dentinal tubules, and different levels of enlargement. CONCLUSION: Our results show that the Er:YAG laser special microprobes are effective in shaping, cleaning, and enlarging straight root canals faster and more efficiently then traditional methods.

Dental Instruments↗

PubMed2002

[CO2 laser surgery for the treatment of vocal cord carcinomas in early stages (T1 T2)].

BACKGROUND: The standard treatment for patients with early vocal cord carcinoma has been radiotherapy. In recent years, encouraging results with CO2 laser surgery has changed our treatment strategy in selective cases. During the past four years at the Rabin Medical Center we have treated patients with carcinoma of the vocal cord using CO2 laser surgery. PURPOSE: We conducted a retrospective study to investigate the results of the Head and Neck Surgery department with CO2 laser treatment for squamous cell carcinoma of the vocal cord during early stages (T1, T2) without radiotherapy. MATERIALS AND METHODS: Twenty one patients with carcinoma of the vocal cords in early stages were treated with CO2 laser. Nineteen patients suffered from stage T1 carcinoma located in one vocal cord, three of these patients suffered from involvement of the anterior commissure and one patient also had involvement with the anterior part of the second vocal cord. Two patients with carcinoma in stage T2, one with involvement of the ventricular band and one with limited movement of the vocal cord. The follow-up period for the patients ranged from one month to four years. RESULTS: Only one patient in stage T1 developed local recurrence after half a year, no patients died during the follow-up. CONCLUSION: Careful patient selection with endoscopic staging also during the biopsy, removal of the carcinoma in free border, strict follow-up and stroboscopic examination are essential to secure good results in the treatment of CO2 laser for early stages of vocal cord carcinoma.

Carcinoma↗

PubMedDate not supplied

Laser surgery for the treatment of glottic carcinomas.

PURPOSE: The standard treatment for patients with early glottic carcinoma in Israel has been radiotherapy. In recent years, encouraging results with laryngo-microscopic carbon dioxide laser surgery as a treatment for early glottic carcinoma has changed our treatment strategy. We conducted a retrospective study to investigate the results of carbon dioxide laser excisional technique for early glottic carcinoma (T1, T2). MATERIALS AND METHODS: Twenty-six had squamous cell carcinoma (SCC), (21 patients with T1 and 5 patients with T2 lesions), 3 had carcinoma in situ, (CIS) and 3 had verrucous carcinoma (VC). RESULTS: All patients were free of disease after salvage treatment at the most recent follow-up. CONCLUSIONS: Careful patient selection with endoscopic staging and strict follow-up are essential to secure good results in the treatment of carbon dioxide laser for early laryngeal carcinoma.

Adult↗

PubMedDate not supplied

A new scoring system using multiple immunohistochemical markers for diagnosis of uterine smooth muscle tumors.

The diagnosis of uterine smooth muscle neoplasms by light microscopy is difficult. Multiple classification schemes have been proposed based on mitotic rate, nuclear atypia, and the presence or absence of necrosis. None of these classification systems has been entirely successful. This study was undertaken to evaluate the use of selected immunohistochemical and histochemical markers in differentiating these tumors, in addition to accepted morphologic criteria. Ten cases of each of the following: leiomyosarcomas (LMS), atypical leiomyomas (AL), cellular leiomyomas (CL) and usual leiomyomas (UL), were classically evaluated for histological diagnosis and were stained for Ki-67 (MIB-1), bcl- 2 and p53 using monoclonal antibodies and the avidin-biotin peroxidase method, and argyrophilic nucleolar organizer region (AgNORs). The number of stained cells was counted in the most positively stained region in a 4 mm2 square cover glass mounted on each slide. The mean value was calculated for each group of tumors. The data for Ki-67 (MIB- 1), bcl-2, p53 and AgNOR staining respectively, were significantly higher in LMS by comparison to UL, CL or AL. Because many singular cases had superimposed data being difficult to diagnose, a new scoring system for pathological evaluation was created. The results obtained by this scoring system suggest that immunohistochemical markers Ki-67 (MIB-1), bcl-2, p53 together with the AgNOR staining could be useful, by the scoring system, as an adjunct to the current accepted morphologic criteria in differentiating smooth muscle tumors of the uterus.

Antigens, Nuclear↗

PubMedDate not supplied

Immunohistochemical profile and treatment of uncommon types of thyroid carcinomas.

The distinction of uncommon types of thyroid carcinomas is important, because their treatment and prognosis differ. The aim of this study was to describe retrospectively the immunohistochemical profile of uncommon types of thyroid carcinomas and mode of treatment. Of the 1194 patients with thyroid carcinomas treated in Rabin Medical Center from 1954 to 2001, 153 were uncommon types (not papillary or follicular carcinomas). Specimens from archival tissue obtained from thyroidectomies in all these cases were revised and immunohistochemically examined. Anaplastic carcinomas (n=59) were positive for high molecular weight cytokeratin (CK HMW), low molecular molecular weight cytokeratin (CK LMW), cytokeratin (CK) 7, CK 8 and 18, thymoglobulin, EMA and vimentin; medullary carcinomas (n=39) were positive for CK LMW, CK 19, CK 8 and 18, CK 10, CK 7, carcinoembryonic antigen (CEA) and calcitonin; Hurthle cell carcinomas (n=30) for CK LMW, CK 19, CK 8 and 18, thyroglobulin, epithelial membrane antigen (EMA) and CEA; squamous cell carcinomas (SCC) (n=12) for CK HMW and cytokeratin total (CKs); lymphomas (n=7) for leukocyte common antigen (LCA) and B-cells (CD 20), and clear cell carcinomas (n=6) for CK LMW, CEA and thyroglobulin. Use of an immunohistochemical panel has diagnostic value in the differentiation of uncommon types of thyroid carcinoma, which help to plan the best mode of treatment.

Carcinoma↗

PubMedDate not supplied

Use of Er:YAG laser to improve osseointegration of titanium alloy implants--a comparison of bone healing.

PURPOSE: The objective of this study was to compare the osseointegration of implants in rats in sites prepared with an Er:YAG laser with osseointegration in sites prepared using a conventional drill by assessing the percentage of bone-implant contact (BIC). MATERIALS AND METHODS: Osteotomies were prepared with an Er:YAG laser in the tibiae of 18 rats (the test group) and drill-prepared with a 1.3-mm-wide surgical implant drill at 1,000 rpm with simultaneous saline irrigation in the tibiae of another 18 rats (the control group). Acid-etched titanium alloy implants (2 x 8 mm) were placed in the tibiae, engaging the opposite cortical plate. The Er:YAG laser was used with a regular handpiece and water irrigation (spot size, 2 mm; energy per pulse, 500 to 1,000 mJ; pulse duration, 400 ms; and energy density, 32 J/cm2). Nine animals from each group were sacrificed after 3 weeks of unloaded healing; the remainder were sacrificed after 3 months. The tissues were fixed and prepared for histologic and histomorphometric evaluation. RESULTS: Statistical analysis showed significant differences between the 2 groups at both 3 weeks and 3 months. After 3 weeks of unloaded healing, the mean BICs (+/- SD) were 59.48% (+/- 21.89%) for the laser group and 12.85% (+/- 11.13%) for the control group. Following 3 months of unloaded healing, the mean BICs (+/- SD) were 73.54% (+/- 11.53%) for the laser group and 32.6% (+/- 6.39%) for the control group. DISCUSSION: Preparation of the implant sites with the Er:YAG laser did not damage the interface; the healing patterns presented were excellent. CONCLUSIONS: Based on the results of this study, it may be concluded that the Er:YAG laser may be used clinically for implant site preparation with good osseointegration results and bone healing and with a significantly higher percentage of BIC compared to those achieved with conventional methods.

Animals↗