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Biomedical subjects

R A Robinson

Publications and source records attributed to R A Robinson.

At least 55 records · Page 3Linked to original sources
PubMed1997

Quantification of surgical margin shrinkage in the oral cavity.

BACKGROUND: Obtaining adequate surgical margins, free of tumor, is crucial for success in oncologic surgery. The head and neck surgeon often finds that the tumor-free margin reported from histopathologic measurement is significantly smaller than the margin measured in-situ. It was the purpose of this study to quantify the change in size of mucosal and muscle surgical margins following excision, formalin fixation, and slide preparation of tongue and labiobuccal tissue in a canine model. METHODS: Ten mongrel dogs under general anesthesia for a concurrent project were used in this study. Changes in mucosal and muscle dimensions around custom-made brass disks, one with a needle depth gauge, were measured immediately following excision after formalin fixation and after slide preparation. RESULTS: The mean shrinkage from initial resection to final microscopic assessment of the lingual surface mucosal margins was 30.7% (p < 0.0001). The deep tongue margin shrank 34.5% (p < 0.0001). The mean shrinkage of the labiobuccal mucosal margin was 47.3% (p < 0.0001). In all cases, the greatest proportion of shrinkage occurred immediately upon resection. CONCLUSIONS: From the in-situ measurement by the surgeon to final pathologic evaluation on the microscope slide, the measured dimensions of oral cavity mucosal and tongue muscle margins shrink significantly. To obtain 5 mm of pathologically clear margin an in-situ margin of resection of at least 8 to 10 mm needs to be taken. Studies reporting clinical correlation of recurrence and survival information with surgical margin status should include a detailed description of the technique used to determine the reported surgical margin status.

Animals↗
PubMed1997

Oral botryomycosis: a case report.

We present a 42-year-old male with botryomycosis initially presenting with left-sided proptosis due to an infraorbital mass. A biopsy through an anterior orbitotomy yielded indeterminate histopathology. The patient later developed a similar oral lesion which was biopsied and found to be botryomycosis. The oral lesion recurred after initial surgical treatment, but responded to antibiotic therapy. Discussion of this case along with a review of the literature is presented to offer guidelines for recognition and management of this rare disorder.

Adult↗
PubMed1997

Atypical glandular cells of undetermined significance. Diagnostic accuracy and interobserver variability using select cytologic criteria.

Histologic follow-up of patients with the Bethesda system cervical-vaginal diagnosis of atypical glandular cells of undetermined significance (AGUS), "favor endocervical origin", or "not otherwise specified" (NOS) shows a high percentage of clinically significant (neoplastic or preneoplastic) lesions. Using the criteria of atypical single cells, irregular nuclear membranes, and decreased cytoplasm, eight observers retrospectively reclassified 88 AGUS, "favor endocervical", or NOS smears using a probabilistic scheme. Follow-up showed 46 clinically significant and 42 benign lesions. The mean accuracy for all observers and the experienced observers was 65% and 72%, respectively. For the experienced observers, the mean specificity of a "favor clinically significant" category was 72%; the mean sensitivity of a "favor benign" category was 90%. For the less experienced observers, subclassification had poor predictive value. We conclude that experienced observers may use specific criteria to correctly subclassify AGUS lesions, and this may aid in patient management.

Female↗
PubMed1997

Value-based pathology: a cost-benefit analysis of the examination of routine and nonroutine tonsil and adenoid specimens.

To study the cost-effectiveness of the histologic examination of tonsil and adenoid specimens, the histologic diagnoses for all routine (2,700) and nonroutine (71) tonsil and adenoid specimens during a 10-year period were reviewed. There were 27 routine cases (1%) and 56 nonroutine cases (79%) with a diagnosis other than normal, tonsillitis, or hyperplasia. Twelve of the 27 routine cases did not have a significant clinical history, and a potentially significant pathologic diagnosis was made in only 6 cases; in none of these cases did the pathologic diagnosis affect patient care. In all nonroutine cases, the pathologic diagnosis affected patient care. The average charge per case to detect potentially significant disease in routine and nonroutine cases was $64,718 and $525, respectively. We conclude that histologic examination of nonroutine cases is cost-effective, whereas in most routine cases with adequate clinical history, histologic examination is not cost-effective.

Adenoidectomy↗
PubMed1997

Hyperbaric dye solution distribution characteristics after pencil-point needle injection in a spinal cord model.

BACKGROUND: The flow-rate limiting and directional characteristics of caudally directed microcatheters, which lead to intrathecal maldistribution of hyperbaric 5% lidocaine, are believed to have contributed to at least 11 cases of cauda equina syndrome. The authors investigated the distribution characteristics of hyperbaric dye solutions via caudally directed side port needles at various rates of injection in a spinal cord model to determine the potential for maldistribution. METHODS: Using a digital video image processing technique, we injected a hyperbaric solution of phthalocyanine blue dye through caudally directed side-port needles into a supinely oriented transparent spinal canal model filled with simulated cerebrospinal fluid. Injections via commonly used spinal needles (24-gauge and 25-gauge Sprotte, and 25-gauge and 27-gauge Whitacre) were recorded using five injection rates (2, 4, 6, 8, and 16 ml/min). RESULTS: For all needles tested, injection rate had a significant effect on the peak dye concentration (P < 0.0001). Injection rates > or = 6 ml/min (2 ml/20 s) resulted in peak dye concentrations of less than 168 mg/1 (extrapolated concentration of 1% lidocaine). Injection via the 24-gauge Sprotte needle, which has a larger orifice area and internal diameter, resulted in significantly lower peak dye concentrations than via the smaller Whitacre needles tested (P < 0.05). CONCLUSIONS: Sacral maldistribution could be minimized by using injection rates > or = 6 ml/min (2 ml/20 s), for all of the side-port spinal needles used in this model study. When very slow injection rates (2 ml/min) are used, peak dye concentrations varied inversely and significantly with needle internal diameter and orifice area.

Anesthetics, Local↗
PubMed1997

Injury from dairy cattle activities.

Animals have been implicated as an important source of injury for farm household members. Little is known, however, about the specific activities associated with the animal/livestock operations that place a person at increased or decreased risk for injuries. The primary aim of this case-control study was to identify which dairy cattle operation activities (that is, milking, feeding, cleaning barns, trimming and treating feet, dehorning, assisting with difficult calvings, and doing treatments) were associated with an increased or decreased risk of injury. We found milking to have the greatest increase in risk for injury. The ratios for increasing hours per week spent at milking (0, 1-10, 11-20, 21-30, 31-63) were 1.0, 2.3, 5.5, 10.9, and 20.6, respectively. We also found an increased rate ratio associated with trimming or treating hooves (rate ratio = 4.2).

Adolescent↗
PubMed1997

Molecular epidemiology of Ornithobacterium rhinotracheale.

Ornithobacterium rhinotracheale is a recently described gram-negative rod-shaped bacterium associated with respiratory tract infections in poultry. In order to determine the molecular epidemiology of this bacterium, we characterized 55 O. rhinotracheale isolates from eight countries on four continents by multilocus enzyme electrophoresis (MLEE), repetitive sequence based-PCR (rep-PCR), and 16S rRNA gene sequencing. MLEE discriminated the O. rhinotracheale isolates into six electrophoretic types (ETs), of which only three ETs were recovered from domesticated poultry. The 16S rRNA gene sequence and rep-PCR analyses confirmed the results obtained by MLEE and indicated limited heterogeneity among isolates of O. rhinotracheale recovered from poultry. Taken together, the results of our analysis demonstrate that the majority of O. rhinotracheale isolates recovered from domesticated poultry throughout the world are represented by a small group of closely related clones and suggest that the bacterium was recently introduced to domesticated poultry from wild bird populations.

Animals↗
PubMed1997

HER-2/neu gene amplification characterized by fluorescence in situ hybridization: poor prognosis in node-negative breast carcinomas.

PURPOSE: The HER-2/neu gene codes for a membrane receptor protein that is homologous, but distinct from the epidermal growth factor receptor. This investigation was performed to validate fluorescence in situ hybridization (FISH) as a sensitive and specific method for assessing HER-2/neu gene amplification in archival tissue and to test whether this alteration is associated with poor prognosis. MATERIALS AND METHODS: HER-2/neu gene amplification was determined by FISH in 140 archival breast cancers, previously characterized for gene amplification by Southern hybridization or dot-blot hybridization, and for gene expression by Northern hybridization, Western immunoblot, or immunohistochemistry. A separate cohort of 324 node-negative breast cancers was assessed for amplification by FISH to determine the utility of HER-2/neu gene amplification. RESULTS: Relative to solid-matrix blotting procedures, FISH analysis of HER-2/neu gene amplification showed a sensitivity of 98% and a specificity of 100% in 140 breast cancers. Among patients treated by surgery only, the relative risks (relative hazard) of early recurrence (recurrent disease within 24 months of diagnosis), recurrent disease (at any time), and disease-related death were statistically significantly associated with amplification. The prognostic information contributed by HER-2/neu amplification was independent of the other markers studied. CONCLUSION: FISH was an alternative technique for determining gene amplification and had some distinct advantages over Southern hybridization. Our results demonstrate that HER-2/neu gene amplification in the absence of adjuvant therapy is an independent predictor of poor clinical outcome and is a stronger discriminant than tumor size. Women with small tumors that had gene amplification were at increased risk of recurrence and disease-related death.

Aged↗
PubMed1997

Animal by-products contaminated with Salmonella in the diets of lactating dairy cows.

As part of a total mixed ration, two rumen-fistulated dairy cows were fed meat and bone meal that had been artificially contaminated with Salmonella spp. Samples from the rumen, feces, and milk were taken 3 d/wk and cultured for salmonella. Rectal temperatures and rumen pH were also measured at the time of sample collection. Over the 2-mo study, salmonella were intermittently recovered from rumen contents, from feces, and from necropsy specimens of rumen contents, cecal contents, and mesenteric lymph nodes. No excretion of salmonella in milk was detected. An elevated rumen pH was associated with increased isolation of salmonella. No clinical illness was observed for either cow. Meat and bone meal that has been contaminated with low concentrations of salmonella is unlikely to result in clinical illness in healthy adult lactating cows. However, dairy producers should continue to be concerned about feed biosecurity and water contamination of animal by-products to prevent and control contamination by salmonella.

Animal Feed↗
PubMed1997

p53, proliferating cell nuclear antigen, and Ki-67 expression in extrauterine leiomyosarcomas.

Extrauterine leiomyosarcomas, because of their relative rarity, are poorly understood in regards to their malignant potential and biologic markers. Many human tumors are characterized by overexpression of p53, a tumor suppressor protein, and by expression of nuclear proteins associated with proliferation, such as proliferating cell nuclear antigen (PCNA) and Ki-67. We examined expression of these markers in 44 extrauterine leiomyosarcomas from 10 men and 25 women who ranged in age from 25 to 82 years (mean, 56 yr). Clinical follow-up was obtained in 34 (97%) of 35 patients, p53 expression was studied with two monoclonal antibodies (1801, D07) by use of an antigen retrieval method. p53 overexpression was present in 19 (43%) of 44 cases, whereas Ki-67 and PCNA staining were seen in 29 (66%) and 36 (82%) of 44 cases, respectively. There was no correlation between overall survival or recurrence and p53 or PCNA and Ki-67 expression. We conclude that p53, Ki-67, and PCNA are expressed in a large number of extrauterine leiomyosarcomas. In this study, the expression of these markers did not predict biologic behavior.

Adolescent↗
PubMed1997

Telepathologic review: utility, diagnostic accuracy, and interobserver variability on a difficult case consultation service.

The diagnostic accuracy of telepathologic analysis has not been compared to that of conventional light microscopic review on a difficult case consultation service. The anatomic pathology consultation files of the University of Iowa were retrospectively examined, and 105 difficult cases from a variety of organs were chosen for real-time telepathologic and light microscopic review. The telepathologic and light microscopic crude agreement of five pathologists were compared, with use of the original consultation diagnosis as the "gold standard." Cases were scored as correct, partially correct, or incorrect. After making a video diagnosis, the pathologists reported whether they wanted to review the case with use of a light microscope. The pathologists performed significantly better with the light microscope, even after excluding cases in areas of inexpertise (P = .005). The mean percentage of cases that the pathologists wanted to review with the light microscope was 64%, and the major reason for review was diagnostic uncertainty. Cases incorrectly diagnosed with use of the video monitor were almost always requested for review. We conclude that, on a difficult case consultation service, pathologists perform significantly better with use of light microscopic than with telepathologic analysis; rarely make an incorrect diagnosis and do not request that case for light microscopic review; and exhibit high telepathologic diagnostic accuracy in areas of expertise.

Adolescent↗
PubMed1997

Nasopharyngeal teratoma. Report of a case with prenatal diagnosis and postnatal management.

BACKGROUND: Oral teratomas are rare entities. CASE: A patient was referred for elevations in the maternal serum alpha-fetoprotein. On ultrasound examination, a cyst was seen protruding from the fetal mouth. Postnatally, a teratoma was found to be filling the neonate's oral cavity. CONCLUSION: This case illustrates problems in determining the etiology of head and neck masses antenatally. It also shows that teratomas can appear to regress and yield positive amniotic fluid alpha-fetoprotein and acetyl-cholinesterase. The appropriate perinatal management of this potentially devastating disorder includes preparation for establishing an airway following delivery.

Adult↗
PubMed1997

Mucinous tumors of the ovary: interobserver diagnostic variability and utility of sectioning protocols.

OBJECTIVES: To determine the interobserver variability of the subclassification of ovarian mucinous tumors and the utility of different sectioning protocols. METHODS: Six pathologists retrospectively reclassified 73 mucinous tumors (30 adenomas, 22 low malignant potential tumors, and 21 carcinomas). Using probabilities, the accuracy of limited sectioning protocols was compared with that of a one section per centimeter protocol. RESULTS: The mean kappa statistic was 0.56, indicating only good agreement. Although a limited sectioning protocol would result in misdiagnosing cases of stage IA carcinoma as a low malignant potential tumor, the overall prognosis of patients with low malignant potential tumors would not markedly change. The prognosis of a patient with a low malignant potential tumor using limited sectioning was within the prognostic range owing to interobserver variability alone. CONCLUSIONS: We conclude that extensive sectioning of ovarian mucinous tumors has limited benefit.

Adenocarcinoma, Mucinous↗
PubMed1997

The survival of Salmonella anatum, pseudorabies virus and porcine reproductive and respiratory syndrome virus in swine slurry.

The survival of Salmonella anatum, pseudorabies virus (PRV), and porcine reproductive and respiratory syndrome virus (PRRSV) in swine slurry was studied at different temperature (4 degrees C, 25 degrees C, and 37 degrees C) and pH (4.0, 7.0, and 10.0) conditions. The longest survival of S. anatum (56 days) was observed at 4 degrees C and pH 7.0. The pseudorabies and the PRRS viruses also survived the longest at 4 degrees C and pH 7.0 but were inactivated within 8 and 14 days, respectively.

Animals↗
PubMed1996

Studies of tum- peptide analogs define an alternative anchor that can be utilized by Ld ligands lacking the consensus P2 anchor.

To determine how peptides that lack a consensus binding motif interact with class I molecules, we have studied the binding of the tumor-associated tum- P91A 14-22 (tum-) peptide to Ld. Previously, a proline at position 2 (P2) and a hydrophobic residue at P9 had been defined as anchors for Ld ligands. However, the tum- peptide lacks the P2 proline anchor. To compare how peptides with and without the P2 proline anchor bind to Ld, we analyzed the binding of monosubstituted analogues of the murine cytomegalovirus (MCMV) pp89 168-176 and the tum- peptides to Ld. As expected, the binding of both peptides was inhibited by substitutions at P9, the carboxyl-terminal anchor. As also predicted, the MCMV peptide was found to be dependent upon its P2 proline for binding to Ld. By contrast, the binding of the tum- peptide to Ld is dependent primarily on a P8 aspartate residue. Interestingly, the p2Ca peptide that is immunodominant in allorecognition of Ld also lacks the P2 proline anchor and has been shown to depend on residues near the carboxyl terminus for binding to Ld. Furthermore, both the p2Ca and the tum- peptides can bind to Ld as octamers. These combined studies suggest that there are at least two alternative manners by which peptides can bind to Ld. Although most Ld ligands bind using a P2 proline anchor, the tum- and p2Ca peptides bind using alternative anchors in the carboxyl-terminal region.

Amino Acid Sequence↗
PubMed1996

Risk factors for advanced-stage oral cavity cancer.

OBJECTIVE: To assess the association between risk factors for inadequate surveillance of oral cavity cancer and stage of disease (localized, T1, T2/N0 vs advanced, T1, T2/N1-3, T3, T4/N0 or N1-3). DESIGN: Convenience sample from a case series. SETTING: Otolaryngology clinic in a tertiary care hospital. PARTICIPANTS: Fifty-three patients with cancer of the oral cavity who were treated at The University of Iowa, Iowa City, from October 1990 through March 1994, participated in the study. Selection criteria included pathologic confirmation of squamous cell carcinoma (SCC) of the oral cavity, the capacity to retrieve data regarding tumor characteristics at initial presentation, and completion of a 30-item questionnaire by the patient. INTERVENTION: Administration of questionnaire identifying factors contributing to inadequate surveillance of cancer of the oral cavity. OUTCOME MEASUREMENTS: Advanced-stage cancer of the oral cavity was identified by the presence of large tumors (T3, T4) and cancer metastatic to the neck lymph nodes (N1, N2, N3). Comparison groups were built to determine the relationship between these two dependent variables and multiple independent variables. Descriptive statistics and tests of association were used to assess relationships. RESULTS: Two of the 53 patients performed self oral examinations specifically designed to screen for cancer prior to finding cancer of the oral cavity. Knowledge of the warning signs of cancer of the oral cavity was denied by 87%. The rate of cancer growth in the oral cavity was variable from first discovery by the patient to the time of tumor staging by otolaryngologists. The interval from discovery of the tumor to tumor staging (delay in diagnosis) was greatest for floor of the mouth cancers and shortest for those cancers located on the tongue. Thirty-seven percent of the patients younger than age 64 years were edentulous in contrast to 62% edentulism in patients older than 65 years. There was a significant, inverse relationship between time since last dental visit and late-stage disease. CONCLUSIONS: Patients with advanced-stage cancer of the oral cavity tended to be elderly, more often wore dentures, and seldom visited the dentist. Treatment of cancer of the oral cavity as localized disease, with an associated decrease in morbidity and mortality, is likely to result by targeting this population as one in need of more intense surveillance.

Age Factors↗