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Biomedical subjects

L C Barr

Publications and source records attributed to L C Barr.

At least 37 records · Page 2Linked to original sources
PubMed1992

Acute tryptophan depletion: a method of studying antidepressant action.

Serotonin (5-HT) has been implicated in the pathophysiology of depressive syndromes and in the mechanism of antidepressant drug action. Rapid dietary depletion of tryptophan (TRP) provides a paradigm for studying the role of 5-HT in depressed patients. Drug-free depressed patients do not show mood changes during TRP depletion but about one third have a clinically apparent, transient improvement in mood on return to normal TRP intake. Depressed patients in clinical remission after 6 to 8 weeks of antidepressant therapy experience a transient depressive relapse during acute TRP depletion. The significance of these findings will be discussed. Tryptophan depletion in other psychiatric syndromes will also be reviewed.

Antidepressive Agents↗
PubMed1992

The serotonin hypothesis of obsessive compulsive disorder: implications of pharmacologic challenge studies.

Demonstration of the efficacy of serotonin (5-hydroxytryptamine; 5-HT) reuptake inhibitors such as clomipramine in the treatment of obsessive compulsive disorder has fueled interest in the neurobiological basis of this illness. Results of treatment studies, investigations of biological markers, and pharmacologic challenges are reviewed and implications for a 5-HT theory of obsessive compulsive disorder discussed. While the nature of the dysregulation in serotonin transmission that may attend obsessive compulsive disorder has yet to be fully elucidated, evidence accumulates that 5-HT function in part modulates obsessive compulsive symptoms. Development of more specific probes and new brain imaging techniques will further enhance understanding of the pathophysiology of obsessive compulsive disorder.

Biomarkers↗
PubMed1991

Influence of local recurrence on survival: a controversy reviewed from the perspective of soft tissue sarcoma.

The relationship between local recurrence and survival has been examined using the example of soft tissue sarcomas of the extremities. Studies that appear to indicate that local recurrence does not jeopardize survival are shown to have been inappropriately analysed, to have inadequate patient numbers, or both. A survival deficit due to local tumour recurrence cannot be excluded on present data, and clinical decisions regarding conservative versus radical surgery will therefore continue to involve an element of value judgement.

Humans↗
PubMed1991

Salvage mastectomy after failed breast-conserving therapy for carcinoma of the breast.

The indications, technique and complications of salvage mastectomy in 25 patients with local recurrence after breast-conserving therapy for carcinoma of the breast have been reviewed. Two patients required myocutaneous flaps to repair the defect, and six patients (24%) suffered wound infection or breakdown. Subsequent local relapse occurred in a total of five patients, two of whom died with uncontrolled chest wall skin nodules.

Axilla↗
PubMed1989

Uncontrolled local recurrence after treatment of breast cancer with breast conservation.

Three hundred fifty-six patients with early (Stage I and II) breast cancer and 55 with advanced (Stage III and IV) breast cancer were treated between 1979 and 1985 with a consistent policy of breast conservation irrespective of tumor site, size, or histologic features. Only three patients underwent primary mastectomy (Stage III), and the remainder were treated either by wide local excision and postoperative radiotherapy (357 cases) or by needle biopsy and primary irradiation (51 cases). A total of seven of 356 (2%) Stage I and II patients have developed uncontrolled local or nodal recurrence at a median follow-up of 5 years, and nine of 55 (16%) of Stage III and IV patients. Of the 62 Stage I and II patients who have died, seven (11%) have died with uncontrolled locoregional disease. Of the 22 Stage III and IV patients who have died, eight (36%) have died with uncontrolled locoregional disease. Although the majority of local recurrences within the conserved breast could be salvaged by secondary surgery (37/38 Stage I and II patients), the development of chest wall or nodal recurrence was usually associated with the appearance of distant metastases and a poor prognosis. Data on uncontrolled local recurrence should be given in all studies of breast cancer treatment, since it represents an important end-point of therapy and a difficult clinical problem.

Breast Neoplasms↗
PubMed1989

Limb conservation for soft tissue sarcomas of the shoulder and pelvic girdles.

Fifty-five patients with soft tissue sarcomas of the shoulder and pelvic girdles were treated between 1982 and 1987 with a consistent policy of limb conservation, using a wide variety of excisional and reconstructive surgical techniques and radical radiotherapy. Actuarial 5-year overall survival was 75 per cent for patients with low or intermediate grade tumours, and 38 per cent for those with high grade tumours (log rank test, P less than 0.05). Five-year local recurrence rates were 32 per cent for low or intermediate grade tumours, and 48 per cent for high grade tumours (log rank test, not significant). Multivariate analysis of the following risk factors for overall survival was performed: age, sex, tumour site, diameter, grade, inadequate surgical margins and local recurrence. Age over 55 years and high tumour grade emerged as independent prognostic variables for survival. Forequarter or hindquarter amputations were undertaken in seven of the 55 patients for local recurrence following previous limb-conserving surgery and radiotherapy. Local failure was not always salvaged by major amputation; satisfactory proximal tumour clearance was achieved in only two of seven patients undergoing major amputation; four of the seven patients developed stump recurrence, three of whom died with uncontrolled local disease. Meticulous attention to surgical and radiotherapeutic technique is required to minimize the incidence of local recurrence while maintaining satisfactory limb function.

Actuarial Analysis↗
PubMed1989

Microvascular anastomoses in diabetes: an experimental study.

The process of intimal repair across a microvascular anastomosis has been studied in an animal model of diabetes using scanning electron microscopy. The mean area of re-endothelialisation at 10 days, 200 microns on either side of an experimental microarterial anastomosis, was 65% in nondiabetic controls compared to 16.5% in an untreated diabetic group and 10% in an insulin treated diabetic group. The degree of intimal repair was significantly lower in the diabetic groups compared to controls (p less than 0.01, Wilcoxon Rank Test). Defective re-endothelialisation may contribute to anastomotic failure in clinical practice.

Anastomosis, Surgical↗
PubMed1989

The primary management of breast cancer: is breast conservation feasible for all patients?

A consecutive series of 411 patients with primary breast cancer treated by a consistent policy of breast conservation, regardless of tumour size, location, clinical stage or histological subtype, is reported. Actuarial 5-year survival was 84% for UICC Stage I, 73% for Stage II and 47% for Stage III/IV. The incidence of local recurrence at 5 years was 13% for Stage I, 12% for Stage II, and 26% for Stage III/IV. The probability of salvage mastectomy at 5 years was 5% for Stage I, 8% for Stage II, and 15% for Stage III/IV. Of local recurrences, 40% were managed with further breast conservation. Primary treatment with breast conservation results in satisfactory local control rates, 5-year survival and cosmesis, but the prevention, diagnosis and treatment of local recurrence within the conserved breast requires further evaluation.

Breast Neoplasms↗
PubMed1985

Transcapsular spread of metastatic squamous cell carcinoma from cervical lymph nodes.

The incidence, extent, and selected clinicopathologic correlations of transcapsular spread from metastatic tumor in the cervical lymph nodes have been investigated in 210 specimens obtained by radical neck dissection from 203 patients with squamous cell carcinomas of the head and neck. Transcapsular spread was detected in 137 of 159 (86 percent) positive specimens, and classified as macroscopic in 74 (54 percent) and microscopic in 63 (46 percent). Macroscopic transcapsular spread was seen most frequently in association with large nodal masses more than 3 cm in diameter (48 of 70 specimens, 69 percent), but also occurred in some specimens with smaller lymph nodes less than 3 cm in diameter (26 of 67 specimens, 39 percent). Anatomic structures most commonly invaded in areas of neck dissection with macroscopic spread from nodal metastases were skeletal muscle (39 dissections) and the adventitial coat of the internal jugular vein (27 dissections). Macroscopic transcapsular infiltration was associated with a high incidence (44 percent) of recurrent tumor in the ipsilateral neck, particularly within 12 months of surgery. Microscopic transcapsular growth was associated with a lower incidence (25 percent) of recurrent tumor in the ipsilateral neck but the difference did not reach statistical significance. Similar recurrence figures (32 percent) were found in the minority of patients whose nodal disease was intracapsular at the time of neck dissection. More precise definition of the morphologic extent of transcapsular spread could be important in clarifying its clinicopathologic correlations.

Adult↗
PubMed1985

Clinical evaluation of the histochemical diagnosis of Hirschsprung's disease.

The histochemical staining of suction rectal biopsies for acetylcholinesterase (AChE) activity is a safe and accurate diagnostic tool in the management of patients with symptoms and signs of Hirschsprung's disease. In this study 101 patients who have undergone AChE analysis of suction rectal biopsies are presented in order to correlate histochemical findings with subsequent clinical course after a minimum of 18 months follow up. There were no false positive results, but the limitations and problems associated with the technique which we have encountered are discussed. Equivocal, atypical, or negative results when contradicting clinical features are indications for repeat biopsy or full thickness biopsy, and awareness of the situations in which false negative results may occur is essential.

Acetylcholinesterase↗
PubMed1984

Diagnostic laparotomy in suspected malignant lymphoma.

The place of laparotomy in the initial diagnosis of malignant lymphoma is investigated by reviewing a group of 25 patients with suspected lymphoma referred for diagnostic laparotomy. Intra-abdominal malignancy was found in 11 patients, although only 7 of these had a malignant lymphoma. A positive alternative diagnosis was made in a further 8 of the remaining 14 patients, but 6 patients remained undiagnosed following laparotomy. A scheme for the investigation of patients with suspected malignant lymphoma is therefore proposed. Patients with an abdominal mass other than a palpable liver or spleen should undergo early laparotomy, while those with no abdominal mass should undergo an extensive screening programme, appropriate to the mode of presentation and similar to that used in the investigation of a pyrexia of unknown origin, in which diagnostic laparotomy is used only as the final step.

Abdominal Neoplasms↗