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Biomedical subjects

B Wilson

Publications and source records attributed to B Wilson.

At least 145 records · Page 8Linked to original sources

In vivo expression of two novel tumor-associated antigens and their use in immunolocalization of human hepatocellular carcinoma.

We are investigating the antigenic changes on the cell surface of human hepatocytes that distinguish the normal from the transformed phenotype using monoclonal antibodies. In vivo expression of antigens has been directly assessed by in situ radioimmunohistology. This technique allows one to determine the distribution and density of antigen expression at the individual cellular level on fresh hepatoma and adjacent uninvolved liver tissue. We have found two antigens recognized by monoclonal antibodies XF-8 and AF-20 that are uniformly present on 15/15 hepatocellular carcinomas tested thus far. Most if not all tumor cells highly express these antigens. Such antigens were not evident on adjacent normal liver and the XF-8 epitope was not found on other normal human tissues. AF-20 antigen distribution revealed low-level expression on a subpopulation of cells in the zona glomerulosa of the adrenal gland and on crypt cells of the small intestinal tract. We have studied the capability of radiolabeled XF-8 and AF-20 monoclonal antibodies when administered either alone or in combination to localize a hepatitis B virus-related hepatocellular carcinoma cell line (FOCUS) grown as subcutaneous tumors in nude mice. Biodistribution experiments demonstrated an excellent localization to tumor of 15 to 22% of the injected dose of 125I-labeled antibodies. Indeed, it was possible to enhance the delivery of 125I to the tumor cell surface by the use of XF-8 and AF-20 in combination. Nuclear imaging studies showed sharp visualization of tumor and demonstrate that these monoclonal antibodies have sufficient specificity and sensitivity to be strongly considered as immunotargeting agents.

Adenocarcinoma↗

In vivo murine studies on the biochemical mechanism of naphthalene cataractogenesis.

The polycyclic aromatic hydrocarbon naphthalene is bioactivated by cytochromes P450 to an electrophilic epoxide intermediate, which subsequently is metabolized to naphthoquinones (NQ) and possibly to a free radical intermediate. These reactive intermediates may bind covalently to lenticular tissues, cause oxidant stress and/or lipid peroxidation, thereby initiating cataracts. To evaluate this hypothesis, male C57BL/6 or DBA/2 mice were treated with naphthalene or one of several naphthoquinone and naphthol metabolites, in the presence or absence of modulators of chemical bioactivation and detoxification. In C57BL/6 mice, cataracts were caused by naphthalene (500-2000 mg/kg ip) in a dose-dependent fashion. The incidence of naphthalene-induced cataracts was decreased by pretreatment with the P450 inhibitors SKF 525A and metyrapone, the antioxidants caffeic acid and vitamin E, the glutathione (GSH) precursor N-acetylcysteine, and the free radical spin trapping agent alpha-phenyl-N-t-butylnitrone (p less than 0.05). Naphthalene cataractogenicity was enhanced by pretreatment with the cytochrome P450 inducer phenobarbital and the GSH depletor diethyl maleate (DEM) (p less than 0.05), and was unaffected by pretreatment with the prostaglandin synthetase inhibitors aspirin or naproxen, or the epoxide hydrolase inhibitor trichloropropene oxide. Cataracts were initiated by 1,2-NQ and 1,4-NQ (5-250 mg/kg ip) in a dose-dependent fashion, with a molar potency about 10-fold higher than that for naphthalene. NQ cataractogenicity was enhanced by pretreatment with DEM (p less than 0.05). 1-Naphthol (56 to 562 mg/kg ip) demonstrated a cataractogenic potency intermediary to that for naphthalene and NQ. DBA/2 mice treated with naphthalene (2000 mg/kg ip), 1,4-NQ (65-250 mg/kg ip), 1,2-NQ (30-250 mg/kg ip), or DEM followed by 1,4-NQ (125 mg/kg ip) did not develop cataracts. These results suggest that naphthalene cataractogenesis in C57BL/6 mice requires P450-catalyzed bioactivation to a reactive intermediate, which may be the NQ and/or a free radical derivative, either of which is dependent upon GSH for detoxification.

Animals↗

Why are amnesic judgements of recency and frequency made in a qualitatively different way from those of normal people?

The Huppert and Piercy (1978) test of recency and frequency judgements was given to a group of 12 non-Korsakoff amnesics of mixed aetiology and to four non-amnesic patients with selective frontal lobe lesions. The results confirmed that non-Korsakoff amnesics show a significant tendency to base their recency and frequency judgements on memory strength and that amnesics with medial temporal lobe damage show this tendency at least with recency judgements. The patients with frontal lobe lesions performed like normal subjects. Patients who were dysexecutive or impaired in cognitive resources were less likely to base recency judgements on trace strength. Such a recency bias was not however, correlated with measures of amnesic severity. The tendency to base frequency judgements on memory strength was not related to either degree of amnesia or reduction of cognitive resources.

Adult↗

The development and validation of a test battery for detecting and monitoring everyday memory problems.

This paper describes the Rivermead Behavioural Memory Test (RMBT)-a short test of everyday memory problems with four parallel forms. It was administered to 118 control subjects aged between 16-69 years with a mean IQ of 106 (range 68-136). The limit of normal performance was established on this group and cut-off points were determined for individual components of the test. The test was also given to 176 brain-damaged people and its validity assessed both by correlating RMBT scores to performance on existing tests, to subjective ratings from patients and carers and to observation by therapists of memory lapses. Validity, parallel form and interrater reliability all proved to be high. It is concluded that the RBMT is a short, reliable, and valid test of everyday memory problems.

Adolescent↗

Child abuse and neglect: an instrument to assist with case referral decision making.

A decision-making instrument was developed to assist reporting agencies and individuals in determining which child abuse and neglect charges would require immediate reporting to a child protection agency and which could be managed initially by the reporting agency. The instrument comprises a matrix scoring system that combines the experience classification of the reporting source and the degree of harm reported. The matrix scoring system was tested for 1 year to evaluate child abuse and neglect cases reported to the New York State Central Registry and Special Services for Children. The goal of the decision-making instrument is to decrease the number of unnecessary reportings to overburdened agencies without jeopardizing the interests of the child. The instrument should assist reporting sources in developing a systematic approach to case referral decision making and should minimize the subjectivity of such decisions.

Adolescent↗

Umbilical artery waveform during bicycle exercise in normal pregnancy.

Eighteen healthy pregnant women in the last half of gestation exercised to 85% of their predicted maximum heart rate on a bicycle ergometer. Pulsed Doppler flow studies before the exercise and during the recovery period were taken close to the umbilical artery's placental insertion site. The systolic-to-diastolic ratio (S/D) of the umbilical artery waveform did not change significantly during the period of observation. In three women, however, a significant increase in the S/D ratio occurred in the first few minutes post-exercise; this was due to a transient fetal bradycardia. In one woman, the S/D ratio remained high despite return of a normal fetal heart rate.

Adult↗

Posttraumatic phlegmasia cerulea dolens: an indication for the Greenfield filter.

Phlegmasia cerulea dolens (PCD) can be a threat to both life and limb and therefore must receive prompt treatment. In most clinical settings, anticoagulant therapy is standard treatment for PCD. Iliofemoral thrombectomy has been recommended as surgical treatment of massive thrombosis where venous gangrene may occur. In the severely traumatized patient, however, massive venous occlusion presents difficulties in management in a complex clinical setting. We have described a 52-year-old white man who had a posterior fracture dislocation of the right hip, with a pulseless, cyanotic, swollen right leg. A Greenfield filter was placed via the internal jugular vein approach, followed by leg and thigh fasciotomy and iliofemoral thrombectomy. Femoral arteriotomy revealed good inflow, and arterial thrombectomy yielded very little thrombus. He subsequently required an above-knee amputation for venous gangrene. In cases of PCD, iliofemoral thrombectomy should be considered early when the threat of venous gangrene exists. We propose internal jugular vein placement of a Greenfield filter before venous thrombectomy. The Greenfield filter has proven to be a safe and effective prophylaxis for thromboembolism should a clot migrate or detach during thrombectomy. Additionally, placement of the filter in the early post-traumatic period would safeguard against pulmonary emboli during a period in which anti-coagulant therapy would be contraindicated.

Accidents, Traffic↗

Immunohistochemical analysis of pulmonary and pleural tumors with the monoclonal antibody HYB-612 directed against the multidrug resistance (MDR-1) gene product, P-glycoprotein.

In this study, 212 untreated primary pulmonary and pleural neoplasms were studied immunohistochemically with the monoclonal antibody HYB-612 which detects the multidrug resistance (MDR)-related P-glycoprotein (gp180). A tumor was considered positive for the expression of the MDR phenotype, even if a single rare positive cell was detected. Using this criterion, all of the various histologic subtypes were found to express MDR to varying degrees. The frequency of expression of this phenotype was found to be notably higher in non-small-cell carcinomas than in small-cell carcinomas. These findings are consistent with the known clinical responses of these neoplasms. The detection of gp180 in untreated lung neoplasms may be predictive of the responsiveness of neoplasms to chemotherapeutic agents. In addition, its presence or absence might be useful in determining the appropriate treatment protocol for given patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

The role of basal cells in attachment of columnar cells to the basal lamina of the trachea.

The mechanism by which basal cells play a role in attachment of airway epithelium to the basal lamina has not been determined. Our hypothesis is that basal cells form a structural bridge between columnar cells and the basal lamina via hemidesmosomes, the cytoskeleton, and desmosomes. To evaluate this hypothesis, we determined the percentage of the columnar cell surface area associated with attachment to the basal lamina and the basal cell in tracheal epithelia of different heights. Tracheas from mice, hamsters, rats, bonnet monkeys, cats, and sheep were prepared for electron microscopy by standard techniques. The height of the epithelia ranged from 8.6 microns in the hamster to 56.8 microns in the sheep. The number of basal cells/100 microns ranged from 3.4 in the hamster to 21.4 in the sheep. The percentage of the basal lamina covered by basal cells increased from 32.6 in the hamster to 94.7 in the sheep. In the shorter epithelia of the hamster, 32% of the columnar cell attachment to the basal lamina was indirect through basal cells, and in the taller epithelia of the sheep, 92% of the columnar cell attachment was by this means. Conversely, the percentage of columnar cell surface in contact with the basal lamina decreased from 67.4% in the hamster to 5.3% in the sheep. These data demonstrate that basal cells play a role in attachment of columnar epithelium to the basal lamina by presenting a surface area for cell-to-cell attachment, thus acting as a bridge between columnar cells and the basal lamina.

Animals↗

School promotion of healthful diet and physical activity: impact on learning outcomes and self-reported behavior.

The Go For Health Program included classroom health education and environmental changes in school lunch and physical education to foster healthful diet and exercise among elementary school children. Interventions were based on social learning theory and implementation was based on an organizational change strategy for school innovations. Two schools were assigned to intervention and two to control conditions. Cognitive measures (behavioral capability, self-efficacy, behavioral expectations) and self-reported diet and exercise behavior were assessed at baseline and following intervention. Data were analyzed by ANOVA using the student and then the school as the unit of analysis. Statistically significant changes were observed for diet behavioral capability, self-efficacy, and behavioral expectations, use of salt, and exercise behavioral capability (fourth grade), self-efficacy (fourth grade) and frequency of participation in aerobic activity. The results provide evidence for program impact on learning outcomes and student behavior.

Behavior Therapy↗

Serologic and virologic analysis of type D simian retrovirus infection in a colony of Celebes black macaques (Macaca nigra).

Celebes macaques were tested for type D simian retrovirus (SRV) infection. SRV infection was first detected in one serum sample collected during 1980. By 1983, 32 of 46 monkeys (70%) were infected. Serotyping of the SRV isolates determined that 0/26 of the isolates were SRV-1; 24/26 were SRV-2; 1/26 was SRV-5; and 1/26 could not be typed. Restriction endonuclease mapping confirmed the SRV-2C and SRV-5 isolates. In addition, two SRV-2C variants were detected.

Animals↗

In vivo localization of human colon adenocarcinoma by monoclonal antibody binding to a highly expressed cell surface antigen.

We have produced a monoclonal antibody (SF-25) against a human hepatoma cell line (FOCUS) that strongly reacts with an antigen shared by all six colon adenocarcinoma cell lines. This cell surface antigen was uniformly expressed in all 17 human adenocarcinomas of the colon obtained at surgery but not on the normal adjacent mucosa counterpart. Other normal tissues were negative except for a population of cells in the distal tubule of the kidney as shown by immunoperoxidase staining and direct binding to membrane preparations. Binding of this Mr 125,000 antigen to antibody is disrupted by detergents, sodium dodecyl sulfate, and paraformaldehyde fixation but not by treatment of FOCUS cells with trypsin. The SF-25 antibody when labeled with 125I shows a striking capacity by both biodistribution and nuclear imaging studies to localize human colon adenocarcinoma grown as solid tumors in nude mice. SF-25 may be useful in distinguishing between normal colon and the transformed phenotype.

Adenocarcinoma↗

Analysis of glycosaminoglycans in bovine retinal microvessel basement membrane.

Glycosaminoglycans (GAG) were isolated from bovine retinal microvessel basement membrane (RMV-BM) and quantitatively analyzed using a recently described competitive binding assay that is specific for and sensitive to nanogram amounts of heparan and chondroitin sulfates. Treatment of osmotically lysed retinal microvessels with the ionic detergent deoxycholate (DOC), required for liberation of the extracellular matrix for plasma membrane lipoproteins and purification of the insoluble matrix, solubilized less than 5% of the GAG in the water-insoluble material. Total GAG content in the DOC-insoluble basement membranes was approx. 0.52 micrograms/mg dry weight; about 70% of the measurable GAG was resistant to both chondroitinase ABC and chondroitinase AC digestion and was sensitive to nitrous acid treatment, indicating its heparan sulfate nature. Cellulose acetate electrophoresis revealed two bands, one of which had an electrophoretic mobility similar to heparan sulfate standard and was sensitive to nitrous acid; the other migrated in the same position as chondroitin sulfate standard and was sensitive to chondroitinase ABC and chondroitinase AC digestion. These results provide evidence that RMV-BM contains chondroitin sulfate(s) as well as heparan sulfate, and offer the first quantitative analysis of GAG in this extracellular matrix.

Animals↗

Frontal amnesia and the dysexecutive syndrome.

This study analyzes the memory deficits shown by an amnesic patient with bilateral frontal damage and a dysexecutive syndrome. He resembles a classic amnesic patient in showing grossly impaired episodic memory for both verbal and nonverbal material, together with normal digit span, and on occasion normal recency in free recall. He differs from the classic amnesic pattern however in showing an impairment in both the speed and accuracy of performance on tests of semantic memory, and in clear evidence for impaired performance on some though not all procedural learning tasks. Finally, his autobiographical memory was poor and subject to substantial confabulation. It is suggested that the pattern of deficits is consistent with a combination of a classic amnesic syndrome with the additional problems associated with the frontal dysexecutive syndrome, rather than exhibiting a qualitatively different form of amnesia.

Adult↗

Semantic, episodic, and autobiographical memory in a postmeningitic amnesic patient.

This study is concerned with the semantic and episodic memory performance of a highly intelligent and intellectually unimpaired patient, K.J., who became amnesic following meningitis. Although densely amnesic he showed unimpaired performance on tests of vocabulary and verbal fluency, while both speed and accuracy on semantic category judgment and sentence verification tests are unimpaired. It is concluded that semantic memory performance may be intact despite dense amnesia. However, this does not necessarily imply separate semantic and episodic memory systems. K.J. showed an impaired capacity for registering new material in semantic memory, and apparently normal autobiographical memory for events occurring well before his illness. The simplest interpretation of our results would therefore appear to be in terms of the sparing of old and overlearned memories rather than the specific preservation of semantic memory.

Amnesia↗