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Biomedical subjects

M D Rohrer

Publications and source records attributed to M D Rohrer.

At least 37 records · Page 2Linked to original sources
PubMed1986

Microwave sterilization of hydrophilic contact lenses.

We used standard 2,450-MHz microwave irradiation to achieve sterilization of hydrophilic contact lenses contaminated with a variety of bacterial, fungal, and viral corneal pathogens. A three-dimensional rotisserie was used to overcome the problem of "cold spots" within the microwave oven. The contact lenses became dehydrated in approximately two minutes. Rehydration with normal saline restored their shape and appearance. The time necessary to prohibit all growth of the bacterial and fungal organisms studied ranged from 45 seconds to eight minutes. All viral contaminants were completely inactivated after four minutes of microwave exposure. Refractive properties were unaffected after 101 exposures to microwaves for ten minutes. Slit-lamp examination and scanning electron microscopy disclosed minute particles on the surface of these contact lenses but no damage to the lens matrix from irradiation.

Bacteria↗
PubMed1985

Microwave sterilization of nitrous oxide nasal hoods contaminated with virus.

Although there exists a desire to eliminate the possibility of cross-infection from microbial contaminated nitrous oxide nasal hoods, effective and practical methods of sterilization in a dental office are unsatisfactory. Microwaves have been used to sterilize certain contaminated dental instruments without damage. In this study nasal hoods contaminated with rhinovirus, parainfluenza virus, adenovirus, and herpes simplex virus were sterilized in a modified microwave oven. Ninety-five percent of the virus activity was destroyed after 1 minute of exposure of the contaminated nasal hoods to microwaves. By the end of 4 minutes, complete inactivation of all four viruses was found. Repeated exposure of the nasal hoods to microwaves resulted in no damage to their texture and flexibility. Microwave sterilization may potentially provide a simple and practical method of sterilizing nitrous oxide anesthesia equipment in a dental or medical practice.

Adenoviruses, Human↗
PubMed1985

Comparison of meclofenamate sodium with buffered aspirin and placebo in the treatment of postsurgical dental pain.

The efficacy of meclofenamate sodium (Meclomen) at two different doses was compared with that of buffered aspirin and placebo in the control of postsurgical pain in a double-blind, randomized study of 205 patients. Meclofenamate sodium, 200 mg, was significantly better than meclofenamate sodium, 100 mg, in some efficacy parameters. Both doses of meclofenamate sodium were superior to buffered aspirin in most parameters of efficacy, and more effective than placebo in every parameter.

Acetaminophen↗
PubMed1985

Microwave sterilization.

This study has shown that representative fungi, viruses, and aerobic and anaerobic bacteria, including spore formers, can easily be killed in a conventional microwave oven with proper modifications. Metal instruments, including air turbine handpieces and burs, and acrylic dentures can be sterilized in short periods. Consistent sterilization can be accomplished only if the items to be sterilized are rotated in a three-dimensional manner throughout the microwave cavity. Arcing back to the magnetron and damage to the microwave oven are prevented by placing a radar absorbent material within the oven and with proper insulation of the item to be sterilized.

Bacteriological Techniques↗
PubMed1982

Histopathology of mixed anaerobic intraabdominal infection in mice.

This study characterized acute peritonitis and chronic abscess formation resulting from experimental mixed anaerobic infection with Bacteroides melaninogenicus and Fusobacterium necrophorum. At intervals after infection liver and spleen samples were obtained, fixed, and processed for histological examination. An acute to chronic infection progressed in mice infected with this mixture of anaerobic bacteria, whereas, no infection resulted when either organism was injected alone. Acute inflammatory cell infiltrates were noted in tissue samples at 12 h postinfection. Small, discrete areas of liver cell necrosis with neutrophilic infiltrates were observed as early as 24 h. By 48 h after infection the liver parenchyma was infiltrated with both acute and chronic inflammatory cells, with moderate to severe hepatocyte degeneration recognized at 72 h. Large intrahepatic abscesses were present in the subphrenic (upper lobe) area 2 to 6 weeks after experimental infection.

Animals↗
PubMed1982

Congenital epulis (gingival granular cell tumor): ultrastructural evidence of origin from pericytes.

The congenital epulis (gingival granular cell tumor) is a rare lesion of unknown origin found only in newborn infants. Remarkable similarities are noted between this lesion and the adult granular cell tumor (myoblastoma) by both light and electron microscopy. An electron microscopic study of a lesion from the anterior mandibular ridge in a newborn male infant was performed. No Schwann cells, axon fibers, odontogenic elements, or any muscle cells could be found. Cytoplasmic features were similar to those in adult granular cell tumors. Cells which appeared to be in a transitional state, not yet true granular cells, were found juxtaposed to the vessels in the position of pericytes. Fine-structure details of these cells were consistent with pericytes. Cells of this type found farther from the vessels appeared more like the typical granular cells. The cells were filled with structures of the autophagic type devoid of normal cell organelles. These findings support the theory that these are nonneoplastic, degenerative, or reactive lesions arising from a mesenchymal cell, possibly the pericyte.

Cytoplasmic Granules↗
PubMed1981

Spontaneous regression of oral histoplasmosis.

A case of histoplasmosis with an unusual clinical presentation and subsequent disease course was diagnosed when a tooth extraction site failed to heal. Culture, biopsy, and serologic study confirmed the presence of Histoplasma capsulatum. Radiographs and sputum culture established pulmonary involvement. Oral and pulmonary lesions regressed without treatment. This case is presented to raise the question of whether all cases of histoplasmosis with oral involvement should be assumed to be disseminated disease requiring treatment with amphotercin B.

Histoplasmosis↗
PubMed1981

Mental nerve paresthesia: symptom for a widespread skeletal metastatic adenocarcinoma.

A case is presented in which the only positive subjective and clinical finding was mental nerve paresthesia. After appropriate and careful workup, in conjunction with medical colleagues, no definitive diagnosis was made until a biopsy of the mandibular canal was performed. The biopsy specimen in this case showed the presence of adenocarcinoma, metastatic to the mandible, thus upholding the axiom that mental nerve paresthesia suggests the existence of a malignant neoplasm. Retrospective comparisons with previous bone marrow aspirates demonstrated widespread, previously unrecognized adenocarcinoma.

Adenocarcinoma↗
PubMed1980

Evaluation of irradiated mandibles using emission tomography, bone scans, and radiography.

This study compared radiographs, bone scans, and computed emission tomograms with histologic findings in irradiated mandibles of adult Rhesus monkeys. Although osteocytes were lost in the path of the beam, many vessels were partially or totally occluded, the periosteum degenerated, the marrow became fibrotic, and cancellous bone proliferated abundantly, no changes were noted with radiography, conventional bone scanning, or computed emission tomograms. These clinical methods of examination may misrepresent the true condition of irradiated bone because of inadequate sensitivity or balance among factors that control radioactive tracer uptake in bone.

Animals↗