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B T Collins

Publications and source records attributed to B T Collins.

At least 37 records · Page 2Linked to original sources
PubMed1989

Pharmacokinetics of methylmercury in the blood of monkeys (Macaca fascicularis).

Statistical analysis of the blood mercury profiles of groups of two and four adult female cynomolgus monkeys (Macaca fascicularis) given single oral doses of 500 micrograms and 50 microCi (25.3 micrograms) methylmercury/kg body wt, respectively, indicates that a two-compartment model best describes the absorption and elimination of methylmercury in blood. Absorption was largely complete within 6 hr, and the half-time of methylmercury during the terminal elimination phase ranged from 10 to 15 days. In addition, three groups of five adult female cynomolgus monkeys were dosed with methylmercury every Monday, Wednesday, and Friday for periods up to 2 years at effective doses of 10, 25, or 50 micrograms methylmercury/kg body wt/day. The average blood levels at steady state were estimated to be 0.27 +/- 0.02, 0.69 +/- 0.03, and 1.51 +/- 0.08 ppm, respectively, with average time taken to achieve 95% of the steady-state blood level being about 92 days. The steady-state blood levels obtained via extrapolation of the results from the two single-dose experiments were significantly different from those actually achieved, indicating that the average steady-state blood levels under chronic dosing conditions may not be accurately estimated on the basis of short-term experiments. The data were also used to examine the impact of different dosing intervals on variation in blood mercury levels.

Animals↗
PubMed1986

Heavy metals and essential elements in livers of the polar bear (Ursus maritimus) in the Canadian Arctic.

Polar bear (Ursus maritimus) livers (67) from six Management Zones in the western and central Canadian Arctic were analysed for 22 elements. Several, Ba, Be, Co, Mo, Ti, V and Zr, were near the detection limit in all cases. Baseline data were obtained for the remaining elements, Ag, As, Ca, Cd, Cu, Fe, Hg, K, Mg, Mn, Na, P, Se, Sr and Zn. No statistically significant effect of age, sex or geographical location was found for any of the elements, except Cd, Hg and Se, for which age and geographical location effects were found. The frequency distribution of Zn levels was bimodal. The second peak in the distribution appeared to be related to elevated levels of Cu. The average level of Cu was 104 mg kg-1 (dry wt.), higher than other marine mammals. Average levels of Cd were significantly higher in the eastern zones, but were always less than 1.0 mg kg-1 (dry wt.), significantly lower than their prey species. This may be due to the preference of polar bears for eating seal skin and fat which is low in Cd. Mercury levels tended to be higher in the western zones bordering the Beaufort Sea, which may be related to a higher proportion of bearded seal in their diet. Mean Hg levels ranged from 20 mg kg-1 in the eastern zones were related to age by the expression: Hg (mg kg-1 dry wt.) = 15.7 + 8.0 Age (years). Mercury levels in the most northerly zone near Melville Island were very high: Hg (mg kg-1 dry wt.) = 18.4 + 27.5 Age (years). Levels of Hg and Se were very highly correlated, with a molar ratio of 1.27:1, Hg/Se.

Animals↗
PubMed1986

Two-generation chronic toxicity study with hexachlorobenzene in the rat.

The toxicological effects of analytical grade hexachlorobenzene (HCB) were examined in a two-generation feeding study in which 40 male and 40 female weanling Sprague-Dawley rats, except where noted, were fed diets containing 0.0 (64 males, 64 females), 0.32, 1.6, 8.0 or 40.0 (66 males, 66 females) ppm HCB. After 3 months on test, the F0 rats were bred and 50 pups (F1) of each sex were randomly selected from every group. At weaning the F0 animals were killed, and the F1 animals were fed their parents' diet for the remainder of their lifetimes (130 weeks). There were no treatment-related effects on growth, feed consumption, haematological parameters or survival in either generation. Increased heart and liver weights were found in the F0 generation males fed 8.0 and 40 ppm HCB. HCB had no effect on fertility, but did significantly reduce pup viability in the 40.0-ppm group. Histopathological changes in the F1 generation included significant linear trends for the incidence of parathyroid adenomas and phaeochromocytomas in both sexes, neoplastic liver nodules in females, centrolobular basophilic chromogenesis of the liver in both sexes, peliosis of the liver in females, peribiliary lymphocytosis of the liver in males and chronic nephrosis of the kidney in males.

Animals↗
PubMed1985

Long-term toxicity of hexachlorobenzene in the rat and the effect of dietary vitamin A.

The toxicological effects of analytical-grade hexachlorobenzene (HCB) were examined in two chronic studies. Study I was an in utero exposure carcinogenicity feeding experiment in which Sprague-Dawley rats, in groups of 40 males and 40 females except where noted, were fed from weaning on diets containing 0.0 (64 M/64 F), 0.32, 1.6, 8.0 or 40.0 (66 M/66 F) ppm HCB. After 3 months on test, the F0 rats were bred and 50 pups (F1) of each sex were randomly selected from every group. From weaning, when the F0 animals were killed, the F1 animals were fed their parents' diet for the rest of their life (130 wk). There were no treatment-related effects on growth, feed consumption, haematological parameters or survival in either generation. Increased heart and liver weights were found in the 8.0 and 40 ppm F0 males. HCB had no effect on fertility but pup viability was significantly reduced in the 40 ppm group. Histopathological changes in the F1 generation included significant linear trends in the incidence of parathyroid adenomas and phaeochromocytomas in both sexes, neoplastic liver nodules in females, centrilobular basophilic chromogenesis of the liver in both sexes, peliosis of the liver in females, peribiliary lymphocytosis of the liver in males and chronic nephrosis of the kidney in males. In Study II, the toxicological effects of HCB were examined as a consequence of varying the dietary levels of vitamin A. In this single generation lifetime (119 wk) feeding study, groups of 50 weanling Sprague-Dawley male rats were randomly assigned to each of the following dietary groups: control, control + 40 ppm HCB, 1/10 the vitamin A content of the control diet, 1/10 vitamin A + 40 ppm HCB, 10 times the vitamin A content of the control diet and 10 times vitamin A + 40 ppm HCB. After 25 and 49 wk on test, five animals from each group were killed and subjected to haematological and histological examinations. All other aspects of evaluation were similar to those for the F1 generation in Study I. No consistent differences were observed in the haematological parameters and there were no significant differences in the incidence of pathological lesions between the test groups. The animals in the 1/10 vitamin A groups, with or without HCB, had significantly lower body weights and poorer survival than did their corresponding control (normal vitamin A) groups.

Administration, Oral↗
PubMed1983

Effect of vehicle on the pharmacokinetics and uptake of four halogenated hydrocarbons from the gastrointestinal tract of the rat.

A variety of low molecular weight aliphatic chlorinated hydrocarbons have a history of use in the processing of foods, and their presence in potable water supplies has also been demonstrated. In this study, the relative uptake of four different aliphatic chlorinated hydrocarbons (methylene chloride, dichloroethane, chloroform and trichloroethylene) was studied after administration, by intragastric intubation, at the same dose level as corn-oil or aqueous solutions. Serial blood samples were collected over a 5-h period and uptake was assessed as the calculated area under blood concentration-time curves. A significant decrease in the rate and extent of uptake was observed for the compounds when administered as an oil solution as compared with an aqueous solution. Lower peak concentrations and an increase in the time taken to reach peak concentration, after dosing with corn oil solutions, was also observed.

Animals↗
PubMed1976

A statistical assessment of the quantitative uptake of vinyl chloride monomer from aqueous solution.

The presence of vinyl chloride monomer (VCM) in foodstuffs and its demonstrated carcinogenic potential when administered by the oral route has raised questions concerning the quantitative estimation of the safety of the use of food packaging fabricated from rigid polyvinyl chloride. A statistical model, which was tested by curve-fitting data obtained from an oral uptake study, has been demonstrated to be of predictive value. Ninety-five percent condifence limits were also calculated, and the data from this study were compared with those from a previous gas phase exposure study. It was concluded that if the total daily liquid intake contained 20 ppm of VCM then the area generated under the blood level-time curve, for rats, would be equivalent to an inhalation exposure of about 2 ppm for 24 hr.

Administration, Oral↗
PubMedDate not supplied

Correlation of fine needle aspiration biopsy and dynamic contrast-enhanced 3D magnetic resonance imaging of the breast.

OBJECTIVE: To correlate and assess the utility of dynamic contrast-enhanced three-dimensional gadolinium-enhanced magnetic resonance imaging (Gd-3DMRI) and fine needle aspiration biopsy (FNAB) findings in patients with suspected breast disease. STUDY DESIGN: Beginning in 1993, all patients who underwent percutaneous FNAB of the breast and had concurrent Gd-3DMRI evaluation of the breast were selected for this study. Findings for FNAB and Gd-3DMRI were stratified into two categories, positive and negative. Subsequent clinical management decisions, which included surgical intervention and/or clinical follow-up, were recorded for all patients. RESULTS: There were 69 FNABs in 59 patients with corresponding Gd-3DMRI evaluation. A positive result by both FNAB and Gd-3DMRI was found in 15 of 18 malignant cases. FNAB missed one case, and Gd-3DMRI missed two, and each of these was thought to be technical. Combining the methods yielded 100% sensitivity. False positive results on Gd-3DMRI (17 cases) were all confirmed to be benign by FNAB and subsequent tissue evaluation. All 32 cases with combined negative results by FNAB and Gd-3DMRI demonstrated a benign process, yielding a specificity of 100% (32/32). CONCLUSION: Our combined testing modalities showed a high degree of specificity and good sensitivity. FNAB used with dynamic contrast-enhanced Gd-3DMRI can contribute valuable information for physicians treating patients with suspected breast abnormalities.

Biopsy, Needle↗
PubMedDate not supplied

Fine needle aspiration biopsy of well-differentiated liposarcoma of the neck in a young female. A case report.

BACKGROUND: Well-differentiated liposarcomas are low grade, nonmetastasizing, malignant neoplasms composed primarily of mature adipose tissue. They are uncommon in the head and neck. CASE: A 24-year-old female presented to the ears, nose and throat clinic for evaluation of a recent, rapidly growing neck mass on the right side. Fine needle aspiration (FNA) biopsy of the mass showed that the smears had fragments of connective tissue with a mixture of mature-appearing fat traversed by bands of fibrous collagen and vessels. Nuclei within the fat and fibrous bands were mildly irregular, hyperchromatic and enlarged, with one or two small nucleoli. Infrequently present but readily identified, lipoblasts were scattered throughout the aspirate smears. A diagnosis of "atypical lipomatous neoplasm" was rendered. Subsequently, the mass was surgically removed. On histologic examination, the tumor was a well-differentiated liposarcoma. CONCLUSION: FNA biopsy of well-differentiated liposarcomas in the head and neck can present difficulties in the classification and diagnosis of this neoplasm.

Adult↗
PubMedDate not supplied

DNA polymerase chain reaction using fine needle aspiration biopsy smears to evaluate non-Hodgkin's lymphoma.

OBJECTIVE: To apply polymerase chain reaction (PCR) analysis to the fine needle aspiration biopsy (FNAB) evaluation of lymphoid proliferations. STUDY DESIGN: We analyzed 37 consecutive archived FNAB malignant lymphoma specimens. Immunophenotypic data from the fine needle aspiration biopsy and excisional biopsy material was available for all specimens. PCR to identify monoclonal rearrangements of the immunoglobulin heavy chain gene, T-cell receptor and translocations involving the bcl-1 and bcl-2 genes was performed. RESULTS: Seventy-eight percent of cases were detected by at least one of these assays. Where DNA analysis was performed on excisional biopsy material, 70% of the cases had identical results; no discordant results for the immunoglobulin heavy chain gene or T-cell receptor were found. In 23% of cases, after review of all available data, a discordant result was thought to be a consequence of a false negative result in DNA analysis of excisional biopsy material. CONCLUSION: These findings indicate that PCR analysis of archived FNAB material, when necessary, provides useful information for diagnosis and staging of malignant non-Hodgkin's lymphomas.

Biopsy, Needle↗
PubMedDate not supplied

Fine needle aspiration biopsy of recurrent and metastatic osteosarcoma.

OBJECTIVE: To assess the utility of fine needle aspiration (FNA) biopsy in evaluating local recurrence or disseminated metastases in patients with osteosarcoma. STUDY DESIGN: Cytology files from Saint Louis University Hospital and Indiana University Medical Center were searched for patients with osteosarcoma who had undergone FNA biopsy for evaluation of local recurrence or disseminated metastases. Clinical information was collected and all aspirate smears reviewed. RESULTS: Six FNA biopsies in five patients were procured by either the percutaneous or radiologically guided method. All six aspirates were diagnostic. Cytologic features showed a discohesive, cellular neoplasm with intermediate to large cells and oval to spindle nuclei. Chromatin was coarsely granular, with single or multiple nucleoli. Aspirate material included multinucleated giant cells and a variable amount of "osteoidlike" extracellular matrix. CONCLUSION: FNA biopsy is accurate, and these results reflect its ability to diagnose osteosarcoma when there is local recurrence or widely disseminated metastases.

Adult↗
PubMedDate not supplied

Combined fine needle aspiration biopsy, and immunophenotypic and genotypic approach to posttransplantation lymphoproliferative disorders.

OBJECTIVE: To report our experience with a combined approach to posttransplant lymphoproliferative disorders (PT-LPDs) that utilizes fine needle aspiration biopsy. STUDY DESIGN: A review of the files in the Department of Pathology, Saint Louis University Health Sciences Center; from 1988 to 1996 identified six patients with a diagnosis of PT-LPD who underwent either percutaneous or radiologically guided fine needle aspiration biopsy (FNAB). In all cases, material was collected for cytomorphology, flow cytometric analysis and, in selected cases, DNA polymerase chain reaction (PCR). Subsequent evaluations and clinical outcomes were obtained from the medical record. RESULTS: The six transplant recipients (4 men and 2 women; 3 cardiac, 2 renal and 1 hepatic transplant) had an age range of 16-65 years. The aspirate material on these six patients had a polymorphic pattern of lymphoid cells with varying sizes. By flow cytometry, two were monoclonal, while four had a polyclonal pattern. DNA PCR analysis on two FNABs demonstrated a monoclonal rearrangement of the immunoglobulin heavy chain gene. CONCLUSION: FNAB provides cytomorphologic characterization of PT-LPDs in transplantation patients and sufficient material for successful use of flow cytometry immunophenotyping and DNA PCR analysis. FNAB, therefore, has an important role in the evaluation of organ transplantation patients and is a valuable tool for assessing and diagnosing PT-LPD.

Adolescent↗
PubMedDate not supplied

Correlation of fine needle aspiration biopsy and fluoride-18 fluorodeoxyglucose positron emission tomography in the assessment of locally recurrent and metastatic head and neck neoplasia.

OBJECTIVE: Patients with primary head and neck neoplasia can present during follow-up with suspected recurrence, and both fine needle aspiration biopsy (FNAB) and fluoride-18 fluorodeoxyglucose positron emission tomography (FDG-PET) scan are available methodologies for evaluating these patients. Our objective was to retrospectively correlate patients who underwent both FNAB and FDG-PET scan in order to assess the possibility of recurrent neoplasia. STUDY DESIGN: The cytopathology files at Saint Louis University Health Sciences Center were retrospectively searched for patients with known primary head and neck malignancies beginning in 1995. Suspected recurrence and local metastases evaluated by both FNAB and FDG-PET scan were correlated. RESULTS: Twenty-eight patients received a combined total of 37 FNABs with concurrent FDG-PET scans. The majority of patients had primary oropharyngeal squamous cell carcinoma with intermixed, single cases of other primary head and neck neoplasms. Thirty of the 32 aspirates with recurrent or locally metastatic disease had combined positive findings by both FNAB and FDG-PET scan, yielding a sensitivity of 94%. One nonspecific and one negative FDG-PET scan came from a patient who had disease confirmed by FNAB. Five patients had negative findings by both methods that were supported by the subsequent clinical course. CONCLUSION: FNAB can provide confirmatory evidence of disease in a clinically suspicious abnormality with nonspecific FDG-PET results. FNAB and FDG-PET are highly sensitive for tumors in cases of clinically suspected recurrence and locally metastatic disease.

Biopsy, Needle↗
PubMedDate not supplied

Fine needle aspiration cytology of penile tumors.

OBJECTIVE: Penile tumors are unusual and can represent neoplastic or inflammatory processes. We report a series of penile tumors diagnosed by fine needle aspiration (FNA) cytology. STUDY DESIGN: Files from the Division of Clinical Cytology, Karolinska Hospital, were searched, and cases of FNA cytology of the penis selected. Clinical information and cytologic diagnoses were recorded and observations from aspiration smears made. RESULTS: Eleven patients had presented to Karolinska Hospital for FNA cytology of the penis. They ranged from 46 to 89 years of age; all were uncircumcised. Tumors were present in various locations, including the glans and shaft. Five patients had squamous cell carcinoma (SCCA) of the penis; three were primary, one locally recurrent and one metastatic from primary lung SCCA. There were three carcinomas metastatic from primary colon, prostate and bladder tumors. There was one each of locally recurrent malignant melanoma, locally metastatic testicular mesothelioma and Peyronie's disease. Discomfort associated with the procedure was tolerable, there were no complications, and each biopsy provided sufficient material for a cytologic diagnosis. CONCLUSION: FNA cytology of penile tumors is a successful, well-tolerated procedure capable of providing a cytologic diagnosis and useful information for patient management.

Adenocarcinoma↗
PubMedDate not supplied

Fine needle aspiration cytology of metastatic olfactory neuroblastoma.

OBJECTIVE: Olfactory neuroblastoma (ONB) is an uncommon malignant neoplasm that originates in the upper nasal cavity. Cytomorphologic descriptions of ONB have been limited to isolated case reports. The features of a series of metastatic ONB diagnosed by fine needle aspiration (FNA) are described. STUDY DESIGN: Cytologic findings in four patients with ONB metastatic to cervical lymph nodes who underwent FNA were reviewed, and the cytomorphologic findings were summarized. Immunocytochemical findings and ultrastructural features with selected immunoelectron microscopy from three cases are described. RESULTS: Aspiration cytology revealed a predominance of single cells with intermixed small, loosely cohesive, three-dimensional cell groups. Cell size was small to intermediate, with round nuclei. There was an overall monomorphic appearance, with minimal nuclear pleomorphism. Chromatin was finely granular and stippled, with multiple, small chromocenters. Cytoplasm in the cell groups had a fibrillary quality and was moderate in amount. Single nuclei were frequently stripped of cytoplasm. Occasional pseudorosettes were noted. Immunocytochemical stains were positive for both neuronspecific enolase and synaptophysin. Ultrastructural examination showed neuritic cell processes with neurosecretory granules and microtubules. Immunoelectron microscopy showed positive labeling of neurosecretory granules by chromogranin A. CONCLUSION: FNA cytomorphology, in combination with ancillary studies, can provide an accurate diagnosis of metastatic ONB.

Adult↗
PubMedDate not supplied

Fine needle aspiration cytology of carcinoid tumors.

OBJECTIVE: To define the cytomorphologic features of carcinoid tumor. STUDY DESIGN: The study consisted of 19 carcinoid tumors sampled by fine needle aspiration. These included 6 pulmonary carcinoids. 11 intestinal carcinoids and 2 aspirates from a patient with a mediastinal carcinoid. The cytomorphologic features of carcinoid tumor were documented, and, in selected cases, immunocytochemical findings were noted. Additionally, the cytology literature concerning carcinoid tumor was reviewed and summarized. RESULTS: Morphologically, the carcinoid tumors consisted predominantly of loose groups with a background of single cells. A striking degree of cellular and nuclear monomorphism was seen in all cases. Nuclei were small and round to oval, and all exhibited a characteristic finely granular, evenly distributed chromatin pattern. Cytoplasm was minimal to moderate in amount and finely granular in appearance. Necrosis and prominent nucleoli were not seen. Positive staining was noted in all seven cases in which immunostaining for chromogranin was performed. Neuron-specific enolase was positive in four of five cases. CONCLUSION: The cytomorphologic characteristics of carcinoid tumors are distinctive, and appropriate ancillary studies can assist in confirming the diagnosis.

Adult↗