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Biomedical subjects

B Rodu

Publications and source records attributed to B Rodu.

At least 55 records · Page 3Linked to original sources
PubMed1991

Determining therapeutic efficacy in recurrent herpes labialis by lesion size analysis.

We devised an experimental model for the analysis of therapeutic efficacy of topical medications for recurrent herpes labialis with a double-blind, placebo-controlled format. Rigid prestudy screening evaluations allowed the enrollment of a homogeneous starting population with characteristic herpetic reactivation in an early stage. Using precise measurements of lesion area for a 5-day period, we evaluated the effects of a novel medication containing tannic acid, which has demonstrated impressive inhibitory effects on herpes simplex virus in many recent studies, and salicylic acid, which has rapid absorption kinetics and substantial topical anti-inflammatory and keratin-disrupting properties. Using parametric and nonparametric tests, we studied differences in mean lesion size and used these measurements to evaluate objective and clinically applicable improvement criteria. Although there were no significant differences in mean lesion size at presentation (day 1) between the active medication and placebo groups, the former demonstrated significantly smaller lesions at days 2 through 5 (p less than 0.05). By day 5, 10 of 14 treated subjects showed improvement as defined by a 25% reduction in lesion size compared with day 1, in contrast to only 2 of 12 subjects in the placebo group (p = 0.0079, Fisher's Exact Test). This model can be employed in the evaluation of topical antiviral agents for herpes labialis in a healthy population, because it standardizes criteria for subject enrollment and provides objective and reproducible measurements of therapeutic efficacy.

Antiviral Agents↗
PubMed1991

Peripheral ameloblastoma: a clinical and histologic study of 11 cases.

Peripheral ameloblastoma (PA) is a rare odontogenic tumor. Previously, only 39 cases of PA had been reported in the English literature. In this article 11 additional cases of PA are presented. Concordance with previous cases was evident with regard to race, clinical appearance, and site of predilection. However, differences were observed with regard to age, sex distribution, and predominant histologic pattern. The average age in the current cases is younger, there is no male bias, and the most common histologic pattern is plexiform rather than follicular or acanthomatous. Recurrence following simple excision is rare, but has been reported. Long-term postoperative follow-up is recommended.

Adult↗
PubMed1991

Comparison of convection heat sterilization units for the orthodontic office.

Convection heat has become a popular means of sterilization for orthodontic practices. Several commercial brands are currently being marketed. This investigation compares the Cox sterilizer, the Dentronix DDS 5000, and a Farberware convection oven by means of thermal and bacteriologic testing. Thermal testing was conducted with a thermocouple in well-defined areas of each oven, while bacterologic evaluation involved Bacillus subtilis spore strips placed in specific sectors. The results showed that specific areas of the Cox sterilizer dropped below 375 degrees F during the sterilization cycle, while the DDS 5000 maintained temperatures above 375 degrees F. The Farberware oven reached a mean temperature (including 1 standard deviation) above 375 degrees F when set at 400 degrees F after the oven was allowed to warm up for 13 minutes. Spore growth was detected in several sectors of both the Cox sterilizer and the DDS 5000. No growth was seen in the Farberware oven.

Dental Offices↗
PubMed1991

Simplified PCR-based detection and typing strategy for human papillomaviruses utilizing a single oligonucleotide primer set.

Utilizing the PCR, we have devised a detection and typing system for the human papillomaviruses (HPVs) that are commonly associated with preneoplastic and cancerous lesions of the genital and aero-digestive tracts: HPV 6, 11, 16 and 18. Utilizing computer sequence analysis, we designed a single, "consensus" set of oligomeric nucleotide primers capable of amplifying a 571-594-bp region of the E1 open reading frame of all of these HPVs. Detection via PCR amplification is followed by restriction endonuclease digestion of the resultant products that yield distinctive and reproducible banding patterns by polyacrylamide gel electrophoresis because of their internal sequence diversity. The system is sensitive, does not require sophisticated molecular biology expertise or radioisotopes and can be modified as new information on HPV types and their relationship to diseases becomes available.

Electrophoresis, Agar Gel↗
PubMed1991

Differential diagnosis of oral mucosal petechial hemorrhages.

Petechiae are pinpoint hemorrhages that occur in subcutaneous or submucosal tissues in a wide variety of conditions. Because of their diversity, the differential diagnosis of oral mucosal petechial hemorrhages is complex. The authors report a case of palatal petechial hemorrhages secondary to episodes of intense vomiting. A review of the many disorders underlying petechial hemorrhages is based on etiologic factors including trauma, platelet abnormalities, clotting factor deficiencies, and defects in vascular integrity.

Adult↗
PubMed1990

The polymerase chain reaction: the revolution within.

This article has attempted to review the basic and more sophisticated applications of the PCR to modern molecular biology research strategies. It is an inherently powerful tool which has immediately impacted research methodology. But it is equally elegant in its theoretical simplicity and it is this quality that will not simply enhance the means to answer research questions, but effect profound and lasting transformations on the basic nature of the questions themselves. This is where the revolution begins.

Gene Amplification↗
PubMed1990

Oncogenes, malignant transformation, and modern medicine.

During the past decade there have been remarkable strides in the understanding of the basic mechanism of cancer. It is now clear that there is a set of genes, known as oncogenes, that can cause cells to become malignant if their expression is altered, either by mutation or overexpression. The products of these genes include growth factors, growth factor receptors, signal tranduction proteins, and DNA binding proteins. The normal cellular counterparts of these genes play very important roles in the regulation of growth and proliferation by normal cells. Another set of genes, anti-oncogenes, also play an important role in preventing abnormal cell proliferation. The remarkable explosion of understanding of the pathophysiology of malignancy has led to a common unifying concept of malignant transformation that applies to all tumors. It is likely that these new insights will lead to improved and more specific treatments for malignant disease in the next decade.

Animals↗
PubMed1990

Stimulation of renal and hepatic c-myc and c-Ha-ras expression by unilateral nephrectomy.

Unilateral nephrectomy induces compensatory hypertrophy of the contralateral kidney in rats, resulting in a 25% weight increase in 14 days. We have demonstrated that expression of the c-myc and c-Ha-ras protooncogenes is increased more than ten-fold in the contralateral kidney within 4 to 8 hr following unilateral nephrectomy in rats. The increased expression of these genes is analogous to the increased expression of c-myc and c-Ha-ras that occurs early in liver regeneration, preceding the first increase in DNA synthesis by at least 20 hr. In order to define the tissue specificity of the signals for compensatory renal hypertrophy, we also determined the early protooncogene response and the proliferative response in the liver of rats following unilateral nephrectomy. The expression of c-myc and c-Ha-ras was also increased (five- to ten-fold) in the livers of these animals. DNA synthesis was stimulated in the contralateral kidney at 26-30 hr following nephrectomy as measured by 3H thymidine incorporation, indicating a hyperplastic response to unilateral nephrectomy. However, there was no increase in DNA synthesis in the liver despite the dramatic increase in c-myc and c-Ha-ras expression. Our data suggest that the early increase in protooncogene expression in response to unilateral nephrectomy is stimulated by circulating signals that are not tissue-specific. Increased protooncogene expression in both kidney and liver following unilateral nephrectomy is an early response to the regenerative stimulus, but later signals must provide the tissue specificity necessary for regeneration and cellular proliferation.

Animals↗
PubMed1988

The pathogenesis and clinical significance of cytologically detectable oral Candida in acute leukemia.

Using serial examination and oral cytology, 50 adult patients undergoing induction therapy for acute leukemia were studied for oral colonization with candida species. Ninety percent of patients were found to be colonized with Candida, with most of these colonizations present by day 14. The 30 patients exhibiting colonization with pseudohyphae received ketoconazole 400 mg daily by mouth. Of 20 patients in this group treated for 5 or more days, Candida organisms were eradicated in nine. Sixteen patients from the above group with persistent colonization on ketoconazole were treated by independent clinical decision for sustained fever and neutropenia with Amphotericin B, but only one responded by elimination of colonization. Seven of the 15 patients who did not initially receive ketoconazole developed Candida dissemination in contrast to two of 30 who received ketoconazole initially (P = 0.003, Fisher's exact test). No patient who initially had or acquired a negative cytology developed oral or disseminated candidiasis. Clinical oral candidiasis occurred in three patients, all of whom were receiving amphotericin B. Approximately 90% of these patients have or develop oral colonization with Candida organisms as identified by oral cytology. Those with colonization, both with and without pseudohyphae present, are at risk for dissemination. Amphotericin B does not eliminate colonization remaining after treatment with 400 mg of ketoconazole daily. More effective diagnostic and therapeutic strategies are needed to identify and eliminate Candida organisms and to prevent disseminated candidiasis in this population of patients.

Acute Disease↗
PubMed1988

Performance of a hydroxypropyl cellulose film former in normal and ulcerated oral mucosa.

Although oral ulcers are commonly encountered in clinical dental and medical practice, current therapeutic options with respect to pain relief are limited. This study evaluated the mucosal binding characteristics and the pain relief and protection properties of Zilactin, a hydroxypropyl cellulose film former. In 12 healthy volunteers, the mean duration of mucosal adherence of Zilactin was 3.92 hours, which was significantly longer than that of a widely available topical preparation (1.38 hours, p = 0.0001). When evaluated in 20 subjects with recurrent aphthous ulcerations, Zilactin demonstrated the ability to significantly decrease ulcer pain over a 4-hour period when compared with the subjects' individual standardized level of initial discomfort, which was used as an internal control for all subsequent steps. Challenge with an irritating citrus beverage was made before and after application of the medication. A significant difference in premedication and postmedication sensitivity was shown (p = 0.0001), indicating that the film provides protection, as well as pain relief. As a result of its unique and tenacious film-forming characteristics, this agent is exceptionally effective in the treatment of oral mucosal ulcerations. Greater awareness on the part of physicians and dentists may lead to the development of additional applications.

Adhesiveness↗
PubMed1988

Clinical and chemical properties of a novel mucosal bioadhesive agent.

Through clinical observations and known chemical properties, this series of studies delineates properties of a new bioadhesive agent available commercially (Zilactin). Using a previously published protocol, we determined that the duration of the film formed on mucosa was not altered after exposure to extremes in temperatures encountered in drinking hot and cold liquids. In addition, through dissection of the agent into several component parts, we were able to determine a specific role for each of the acidic ingredients. It is clear that the solubility of hydroxypropyl cellulose (Klucel) is altered by esterification of the polymer by tannic and salicylic acids and that boric acid effectively crosslinks these to form Zilactin's characteristic clinical film. Other fine points of the chemical reactions are detailed. These studies are intended to serve as a foundation for the future manipulation and application of this agent in oral mucosal diseases.

Adhesiveness↗
PubMed1988

In vitro virucidal activity by components of a topical film-forming medication.

This study evaluated the in vitro virucidal activity of soluble components of a topical film-forming medication, Zilactin, against Herpes simplex virus type 1 (HSV-1). Using a standard plaque reduction assay, a 1:10 dilution of the experimental liquid resulted in total destruction of infectious HSV-1. The phenomenon could not be explained by ethanol concentration or lowering of pH, both of which had no effect on control samples. As employed in this assay, Zilactin diluted 1:10 did not demonstrate cyctotoxicity to the cell monolayer system. The implications of these findings on the design and implementation of clinical trials are discussed, with special reference made to the restrictions imposed by the natural history of clinical lesions caused by HSV-1.

Animals↗
PubMed1987

Acute myelofibrosis and multiple chloromas of the mandible and skin.

Acute myelofibrosis is a rare clinical entity characterized by severe marrow fibrosis and peripheral blood pancytopenia. It may be very closely related to and has been considered synonymous with megakaryocytic leukemia. Chloroma is also a rare entity composed of a localized collection of immature myeloid cells and is associated with a known or covert leukemia. A patient presenting with a rare combination of acute myelofibrosis, megakaryocytic leukemia and multiple chloromas of the mandible and skin, are described. Although presenting a diagnostic challenge, their combination in one patient aids in the understanding of the myeloproliferative process. To our knowledge, this is the 3rd case of chloroma involving the oral osseous structures.

Acute Disease↗
PubMed1987

The implications of inflammation in odontogenic keratocysts.

The histologic features of 112 odontogenic keratocysts (OKC's) were examined from both a clinical and histopathological perspective with emphasis on the microscopic presence of inflammation and its relationship to transformation of the classic epithelial cyst lining found in OKC's to a nonkeratinized lining characteristic of common inflammatory odontogenic cysts. Eighty-five (76%) of these cases exhibited inflammation. The sensitivity of inflammation as a predictor of this aforementioned transformation is 100%, and its positive predictive value is 88%. The specificity of the same parameters remains high at 73%. Using previous studies, the implications of these findings on the biologic behavior of OKC's is discussed with special reference to therapeutic considerations.

Adolescent↗
PubMed1987

New developments in understanding phenytoin-induced gingival hyperplasia.

In approximately half of the patients taking phenytoin, gingival fibroblasts proliferate, causing tissue overgrowth and gingival hyperplasia. Recent clinical and basic research is reviewed, describing the conditions associated with phenytoin therapy and gingival hyperplasia.

Gingival Hyperplasia↗