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Biomedical subjects

R L Zimmerman

Publications and source records attributed to R L Zimmerman.

45 records · Page 3Linked to original sources
PubMed1975

Effect of water on piezoelectricity in bone and collagen.

Interferometric measurements of bovine bone and tendon show that the values of the piezoelectric strain constant d14 decrease with hydration from the dry values of 0.2 X 10(-14) and 2.0 X 10(-14) m/V, respectively. The decrease of piezoelectricity in tendon is exponential with a characteristic hydration of 7% by weight from which an upper limit of the average molecular weight of the responsible electric dipole moments is deduced. The piezoelectricity in bone decreases relatively slowly with hydration indicating that the electric dipoles in bone collagen are subject to a different cancelling mechanism.

Animals↗
PubMedDate not supplied

A new radiation dosimeter using a pyroelectric detector.

We describe a new type of radiation dosimeter, for the diagnostic x-ray region, using a pyroelectric detector. It consists of a PZT ceramic crystal thick enough to absorb all the incident radiation at 33 keV. This pyroelectric radiation dosimeter (PERD) produces an electrical signal when exposed to a chopped beam of x-ray photons. The PERD is basically a microcalorimeter. It has the following characteristics: (1) it responds linearly to the energy fluence rate of the radiation; (2) it responds linearly to the radiation intensity for a given radiation spectrum; (3) it has excellent stability; (4) it is simple to construct and inexpensive; and (5) it is rugged.

Electricity↗
PubMedDate not supplied

Diagnostic utility of sialosyl-Tn in discriminating carcinomatous cells from benign mesothelium in body cavity effusions.

OBJECTIVE: Detecting malignant cells in the setting of reactive mesothelium can be difficult. Several techniques have been tried but without widespread acceptance. Sialosyl-Tn (STn) is an aberrantly glycosylated precursor of the MN blood group antigen frequently expressed in carcinomas and dysplastic epithelium. We investigated the STn monoclonal antibody for its clinical utility as an isolated stain to discriminate benign mesothelium from malignant cells. STUDY DESIGN: Cell block material from 72 cases of body cavity fluids were immunostained for STn using the avidin-biotin complex method without antigen retrieval. Slides were incubated overnight at 4 degrees C in a humidified chamber. RESULTS: Strong immunoreactivity was noted in 31/40 (77%) carcinomatous cases. Only moderate staining was noted in 1 of 28 (4%) benign effusions and weak staining in 5 (18%) additional benign cases. Specificity was 100%, sensitivity 78%, positive predictive value 100% and negative predictive value 76%. No staining was noted in four noncarcinomatous malignant effusions. CONCLUSION: STn may have diagnostic value in this cytologic setting as part of a diagnostic panel but not as an isolated stain.

Antigens, Tumor-Associated, Carbohydrate↗
PubMedDate not supplied

Fine needle aspiration diagnosis of a pulmonary metastasis from a cutaneous adenoid cystic carcinoma. A case report.

BACKGROUND: Primary cutaneous adenoid cystic carcinomas (CACC) rarely metastasize to the lung. The few documented cases have been diagnosed by surgical biopsy. CASE: An 82-year-old female presented with an enlarging lung mass 15 years after being diagnosed with CACC. The diagnosis of metastatic adenoid cystic carcinoma was made following a computed tomography-guided fine needle aspiration (FNA) biopsy. CONCLUSION: Metastatic CACC in the lung can be diagnosed by FNA. Knowledge of the patient's clinical history and morphologic variants of CACC is important in making the diagnosis.

Aged↗
PubMedDate not supplied

Clinical utility of chromosome 17 alpha satellite probe in distinguishing benign mesothelium from malignant cells: a pilot study using routinely fixed specimens.

Fluorescent in situ hybridization has shown promise in detecting malignant cells in body cavity effusions. However, this requires special preparatory techniques not used in many laboratories. We developed an in situ hybridization (ISH) procedure specifically for ethanol-fixed specimens, and using it tested the clinical utility of the chromosome 17alpha satellite probe (C17alpha). ISH with C17alpha was used in 12 malignant and 10 benign ethanol-fixed body cavity effusions. Cells were pretreated with protease K prior to ISH. The probe was detected by an anti-digoxigenin-horseradish peroxidase method. Signals were counted in 100 nuclei and the chromosome index (CI) and percent diploid cells calculated in each case. ISH was successfully performed in all cases. Malignant cells had an average CI of 2.23 with less than 44% diploid nuclei and 50% of specimens exhibited bizarre signals. Benign effusions had an average CI of 1.98 with over 84.6% diploid nuclei. Questionably bizarre signals were seen in two (20%) benign specimens. ISH can be performed on ethanol-fixed specimens. The C17alpha probe may prove valuable in detecting malignant cells in body cavity effusions.

Chromosomes, Human, Pair 17↗
PubMedDate not supplied

Evaluation of the c-Met immunostain to detect malignant cells in body cavity effusions.

The cytologic diagnosis of malignant cells in serous effusions can be difficult. A wide variety of immunostains and other diagnostic techniques have been studied but without widespread acceptance of one staining panel or technique. Expression of the tyrosine kinase c-Met has been associated with several malignancies but not with benign mesothelium. We investigated the diagnostic value of the c-Met immunostain in serous effusions. Cell block material from 76 cases of unequivocally benign or malignant effusions were studied. Cases were stained with c-Met using the avidin-biotin complex method following antigen retrieval. The presence of strong granular cytoplasmic staining that was distinct from background staining was considered positive. Positive cells were identified in 38 of 42 (90%) malignant cases and in 18 of 34 (53%) benign cases. Typically, benign cases contained only individual positive cells, but positive cell clusters were also identified. The c-Met immunostain lacks sufficient specificity to be clinically useful in this cytologic setting. The expression of c-Met in benign mesothelium may reflect mesothelial proliferation.

Adenocarcinoma↗