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Biomedical subjects

W J Wilson

Publications and source records attributed to W J Wilson.

At least 37 records · Page 2Linked to original sources
PubMed1994

Cholinergic manipulations and passive avoidance in the rat: effects on acquisition and recall.

A review of the literature concerning cholinergic manipulations and passive avoidance reveals that state-dependency is usually not controlled adequately, nor is acquisition of the passive avoidance task ascertained before retention is tested. These problems make interpretation of results difficult. We report three experiments on 129 rats, controlling both of these factors, in which scopolamine and pilocarpine impaired both acquisition and retention of a passive avoidance response. Lesions of the nucleus basalis magnocellularis had no effect on this task. The results suggest that an optimal level of central cholinergic activity exists for learning and memory, and that deviations from this optimal level impair acquisition and retention.

Acetylcholine↗
PubMed1993

Expression and prognostic significance of estrogen and progesterone receptors in adenocarcinoma of the uterine cervix. An immunocytochemical study.

BACKGROUND: Adenocarcinoma of the uterine cervix typically is an aggressive neoplasm with a propensity for early invasion and dissemination. Little data are available correlating histologic, histochemical, or immunocytochemical parameters with the biologic behavior of this neoplasm. Specifically, the implication of expression of estrogen and progesterone receptors in cervical adenocarcinoma is essentially undefined. METHODS: An immunocytochemical hormone receptor assay using specific monoclonal antibodies against estrogen receptors (ER) and progesterone receptors (PgR) was used to study paraffin-embedded specimens from 54 patients with primary cervical adenocarcinomas. The specimens were evaluated for heterogeneity and intensity of staining. An attempt also was made to study the relationship between the pattern of hormone receptor expression and other established prognostic indicators. RESULTS: In all patients, diffuse positive staining of benign endocervical epithelial or stromal cells was observed. Positive immunostaining was seen in the adenocarcinoma specimens of 16 of 54 (30%) patients for ER and 19 of 54 (35%) patients for PgR. Expression of ER and PgR statistically correlated with each other (P = 0.0001). Endocervical-type adenocarcinoma had the highest degree of staining for both ER and PgR. Clear cell carcinomas and intestinal-type carcinomas were negative for both receptors. Positivity for ER and PgR inversely correlated with histologic grade as defined by the International Federation of Gynecology and Obstetrics (FIGO). The relationship between hormone receptor expression and FIGO stage was not statistically significant. Survival was associated with clinical stage (P = 0.004) and with immunocytochemical status of ER expression (P = 0.032) and PgR expression (P = 0.009). CONCLUSIONS: This study of 54 specimens from patients with cervical adenocarcinoma suggests that positive expression of ER and PgR is associated with prolonged survival.

Adenocarcinoma↗
PubMed1992

Antibody to hepatitis C virus increases with time on hemodialysis.

We studied whether chronic hemodialysis is associated with an increased risk of exposure to hepatitis C virus. Utilizing a first generation Elisa assay (C-100 Elisa, Ortho Diagnostic Systems, Raritan, NJ) and the Chiron RIBA HCV second generation assay (RIBA, Chiron, Emeryville, CA and Ortho Diagnostic Systems, Raritan, NJ), antibody to HCV was found in 31 of 87 hemodialysis patients (36%). Patients on hemodialysis less than 2 years had an antibody incidence of 15% (n = 46), as contrasted with a 59% incidence for patients on dialysis greater than or equal to 2 years (n = 41). We were unable to demonstrate a correlation of HCV-antibody positivity with history of blood transfusion. The overall incidence is higher than previously reported for hemodialysis patients in the United States. The very high incidence found in patients on dialysis greater than or equal to 2 years suggests that factors in the hemodialysis unit might contribute to the spread of virus.

Blood Transfusion↗
PubMed1990

Combined reconstruction of the anterior cruciate ligament in competitive athletes.

Fifty-eight professional and competitive amateur athletes had a combined reconstruction of the anterior cruciate ligament, with use of the semitendinosus tendon for the intra-articular portion of the reconstruction and a strip of iliotibial band for the extra-articular augmentation. Thirty patients (thirty-two knees) were evaluated two to seven years postoperatively to assess the results and the ability to return to athletics. Follow-up consisted of an interview, clinical and roentgenographic examinations, and testing with an arthrometer. Six patients (20 per cent) had a rating of excellent; twenty-two (73 per cent), good; and two (7 per cent), fair. There were no poor results. Of the thirty-two knees, twenty had an associated injury: twenty meniscal tears in eighteen knees, three tears of the medial collateral ligament, four osteochondral fractures of the lateral femoral condyle, and two loose bodies. Combined reconstruction of the anterior cruciate ligament resulted in improved stability of the knee in these patients whose goal of treatment was to be able to resume sports at a highly competitive level.

Adolescent↗
PubMed1989

Intraoperative autologous transfusion in revision total hip arthroplasty.

The records of ninety-eight patients (100 hips) who had revision total hip arthroplasty were reviewed to evaluate the efficacy of intraoperative autologous transfusion in reducing homologous blood-transfusion requirements. In the fifty hips in the study group, a mean of 685 milliliters of autologous blood, or 47 per cent of the estimated loss of blood, was transfused intraoperatively. During the entire course of hospitalization, the mean of the total homologous blood-transfusion requirements was 795 milliliters in thirty-nine study-group patients, compared with 1160 milliliters in forty-six control-group patients who did not have autologous transfusion. This difference was statistically significant (p less than 0.029). Eleven patients in the study group and four patients in the control group did not receive homologous blood. Over-all, the use of intraoperative autologous transfusion was directly responsible for a 42 per cent reduction in the total amount of homologous blood that was transfused.

Adult↗
PubMed1988

Synovial chondromatosis.

Two patients were evaluated for a complaint of long-standing hip pain. No etiology of their progressively disabling symptoms was found by routine diagnostic studies. Hip arthrography and arthrotomography in each case, however, demonstrated multiple intraarticular filling defects consistent with nonradiopaque loose bodies. These were subsequently confirmed at arthrotomy. Synovial chondromatosis is a rare disease in which intrasynovial cartilage metaplasia results in multiple intracapsular loose bodies. Its presence in plain radiographs is uncommon, but has been previously documented. This can account for frequent long delays in accurate diagnosis. Arthrography and/or arthrotomography, however, can be key diagnostic tools. They are recommended in the evaluation of patients whose relatively normal initial clinical examination, laboratory, and roentgenographic studies fail to adequately explain the presence of genuinely disabling symptoms.

Adult↗
PubMed1988

Lesions of the mesolimbic dopamine system disrupt signalled escape responses in the rat.

Classically conditioned shuttling and escape responses of 14 rats with 6-hydroxydopamine lesions of the ventral tegmental area (VTA) were compared with those of 16 sham-lesioned control rats in an aversive classical conditioning paradigm. Although the 6-OHDA lesion did not enhance classically conditioned shuttling, it eliminated the facilitation of escape responses by the conditioned stimulus. Thus, whereas the classically conditioned sham-lesioned rats were faster to escape shock than were the pseudoconditioned sham-lesioned rats, the 6-OHDA classically conditioned and pseudoconditioned rats were equally slow to escape. This suggests that the ability of the rat to respond appropriately to the motivational or informational content of the warning signal was disrupted following damage to the mesolimbic dopamine system.

Animals↗
PubMed1987

Effect of blood pressure on medial medulla-induced muscle atonia.

Stimulation of the medial medullary reticular formation (MMRF) has long been reported to produce generalized inhibition of skeletal muscle activity. However, several studies have reported that in most cases MMRF stimulation produces only increases in muscle tone. In the present investigation we have found that blood pressure is a critical variable, determining whether MMRF stimulation will produce muscle excitation or inhibition. When mean arterial pressure (MAP) was greater than 80 mmHg but less than 148 mmHg, MMRF stimulation produced muscle antonia. Reductions of blood pressure by pharmacological or mechanical techniques induced a reversal of response to MMRF stimulation; stimulation that produced inhibition in base-line conditions produced excitation after MAP reduction. MAP reductions of as little as 10% could cause the reversal response. In contrast, the EMG reduction to MMRF stimulation was not changed or was augmented when MAP was raised. MMRF induced atonia, and its reversal by blood pressure reduction persisted after bilateral isolation of the carotid sinus combined with vagotomy, and in the 6-hydroxydopamine-treated cat. Spinal transection at the cervicothoracic junction did not block atonia or the reversal response. It is suggested that the reversal is mediated centrally.

Adrenal Medulla↗
PubMed1987

Ventral tegmental area lesions do not enhance appetitive classically conditioned responses in the rat.

An autoshaping procedure, in which presentation of a retractable lever signalled food delivery, was used to assess the effects of ventral tegmental area lesions on appetitive classically conditioned responses in 28 rats. Rats with ventral tegmental area lesions did not differ from sham-lesioned rats in acquiring classically conditioned lever press responses, or in learning to withold these responses when an omission contingency was in effect. This lack of effect in an appetitive setting stands in contrast to our previous finding that aversive classically conditioned responses are facilitated by this lesion, and suggests that the ventral tegmental area lesion selectively enhances aversively motivated behaviors.

Animals↗
PubMed1987

Ventral tegmental area lesions differentially affect responses controlled by CS-US contiguity and response-reinforcer contingency in the rat.

Rats with electrolytic lesions of the ventral tegmental area (VTA, n = 32), or sham lesions (n = 32), were tested in four behavioral paradigms in a shuttlebox. The paradigms were designed to assess the motivational influence of CS-US contiguity and response-reinforcer contingency. The VTA lesion increased the number of shuttle responses in the paradigms involving contiguity between a warning signal and a shock, without affecting responses controlled by the contingency between shuttling and shock avoidance. Escape latency was reduced by the lesion, but the general locomotor activity of the rats was not increased.The data suggest that the VTA normally acts to inhibit behavior motivated by classically conditioned fear. The results are discussed in terms of the hypothesis that the dopaminergic projection from the VTA to the nucleus accumbens plays a role in the inhibition of emotionally motivated motor responses.

Animals↗
PubMed1986

High resolution surface coil magnetic resonance imaging of the spine: normal and pathologic anatomy.

In a brief two year period, magnetic resonance imaging of the spine has developed from a single slice, low signal/noise ratio, extremely time consuming technique to a multiplanar, high resolution examination that can be performed in a time frame similar to that of CT imaging. MR has already assumed a primary imaging role in myelopathic states. It is premature to evaluate its place vis-a-vis CT and myelography in many other disease states of the spine, but clearly, MR is assuming an ever expanding role. As technical improvements continue, it is perhaps realistic to predict that magnetic resonance will, in the near future, assume a dominant role in the imaging of the spine for the demonstration of most types of spinal disease.

Adult↗
PubMed1985

Pharmacological manipulations of the nucleus accumbens: effects on classically conditioned responses and locomotor activity in the cat.

Agonists and antagonists of dopamine, acetylcholine, and glutamate were injected bilaterally into the nucleus accumbens in 5 adult cats, and their effects on classically conditioned responses and locomotor activity were observed. Dopamine reduced conditioned consummatory responses (leg flexion and vocalization) and conditioned changes in respiration rate, but did not affect other conditioned preparatory responses (changes in heart rate and respiration amplitude). The cholinergic agonist oxotremorine reduced both conditioned and unconditioned leg flexion. The glutamatergic agonist and antagonist had no effect on any of the conditioned responses. All drugs except haloperidol increased the cats locomotor activity in an open field setting. The results suggest that dopaminergic input to the nucleus accumbens is involved in the inhibition of consummatory conditioned responses, and that the behavioral effect of dopamine in the nucleus accumbens might be dependent on the emotional state of the animal.

Animals↗
PubMed1983

Nucleus accumbens inhibits specific motor but not nonspecific classically conditioned responses.

A classical leg flexion conditioning paradigm was used to elicit specific motor responses, as well as nonspecific responses requiring less involvement of the motor system, in cats. Stimulating and lesioning the nucleus accumbens differentially affected these two types of responses. The specific conditioned responses, leg flexion and vocalization, were suppressed by stimulation and enhanced by lesions of the nucleus accumbens. The nonspecific responses, changes in respiration rate and amplitude, and in heart rate, were affected inconsistently or not at all. This suggests a role for the nucleus accumbens in the inhibition of motor components of learned emotional responses, and is consistent with hypotheses holding that the nucleus accumbens gates the access of the limbic system to motor systems.

Animals↗
PubMed1982

Radiographic identification of loose bodies in the traumatized hip joint.

Acrylic spacers and cubes of cortical bone of known dimensions were placed in predetermined locations in cadaver hip joints, which were then studied with plain radiography and linear, hypocycloidal, and computed tomography (CT). Joint space widening was not measurable on plain radiographs of the pelvis when 2-mm spacers were placed anywhere within the hip joint. When 4-mm spacers were used, widening measured 2 mm in the axis of measurement corresponding to the location of the spacer. Linear tomography did not permit identification of the 2-mm cubes; however, hypocycloidal tomography and CT consistently showed them anywhere within the hip joint. Radiation dose and clinical recommendations are discussed.

Cadaver↗
PubMed1979

Utilization of computed tomography scanners and the health planning issue: a process data summary.

Studies were made of the computed tomography (CT) scanning process at three hospitals. The data collected, while of interest to hospital administrators and radiologists, are particularly significant in view of the current structure of health planning guuielines. The data show clearly that the utilization potential of a particular CT scanner is a function of patient demand, scan time, the ratio of head to body procedures, and medical practice insofar as contrast medium administration is concerned. This paper summarizes the results of the hospital studies and documents the implications of the data for health planning guidelines.

Adult↗