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V Barker

Publications and source records attributed to V Barker.

10 recordsLinked to original sources
PubMed2001

TNFalpha contributes to the death of NGF-dependent neurons during development.

Many sympathetic and sensory neurons depend on a supply of nerve growth factor (NGF) from their targets during development, and neurons that fail to obtain sufficient NGF die by apoptosis. Here we show that tumor necrosis factor alpha (TNFalpha) is involved in bringing about the death of NGF-deprived neurons. Function-blocking antibodies against either TNFalpha or TNF receptor 1 (TNFR1) rescued many sympathetic and sensory neurons following NGF deprivation in vitro. Fewer sympathetic and sensory neurons died during the phase of naturally occurring neuronal death in TNF-deficient embryos, and neurons from these embryos survived in culture better than wild-type neurons. These neurons coexpress TNFalpha and TNFR1 during this stage of development, suggesting that TNFalpha acts by an autocrine loop.

Animals↗
PubMed1987

Use of percutaneous needle biopsy in the investigation of solitary pulmonary nodules.

Percutaneous needle biopsies were performed on 683 patients with solitary pulmonary nodules during 1976-84. A cytological diagnosis of malignancy was made from the first biopsy in 473 patients (69%). A second biopsy was performed in 43 patients, a diagnosis of malignancy being made in a further 16 cases (37%). Histological material was available for comparison with cytological findings in 203 patients. Cytological examination was reliable in the diagnosis of malignancy with a high yield (75%) and low false positive rate (1.5%). Specific benign lesions were correctly diagnosed in 10 patients (1.5%). There was a false negative rate for the diagnosis of malignancy of 18% for the patients with a subsequent histological diagnosis. This compares with a false negative rate of 9% overall; the true rate probably lies between these figures. These results imply that a cytology report indicating no evidence of malignancy, but not diagnostic of a specific benign condition, does not reliably exclude a malignant lesion. In this series cytological typing was not accurate at predicting the cell type determined by histological examination (61% agreement) and was not able to discriminate between small cell and non-small cell lung cancer.

Adenocarcinoma↗
PubMed1981

Diagnostic accuracy of cytology and biopsy in primary bronchial carcinoma.

The accuracy of diagnosis in 656 patients with the four common histopathological types of primary lung cancer has been assessed by comparing the cell type diagnosis made on cytological and histological investigation with that determined by examination of the surgically resected or necroscopy specimen. The accuracy of diagnosis achieved by cytological examination of sputum and bronchial aspirate, and by bronchial biopsy histology was over 85%. The least accurate diagnostic procedure was percutaneous needle biopsy (62%). Squamous and small cell tumours were accurately diagnosed by all four investigations but errors were made in the diagnosis of large cell and adenocarcinomas. Nearly half the number of patients (43%) with large cell carcinoma were later reclassified as having squamous carcinoma and of the patients with adenocarcinoma 32% had been predicted to be squamous and 18% large cell carcinoma. We consider such quality control of pretreatment diagnosis mandatory in management of individual patients and before enrollment in clinical trials.

Adenocarcinoma↗
PubMed1979

Diagnostic accuracy of cytology and biopsy in primary bronchial carcinoma.

The accuracy of diagnosis of cell type obtained from sputum cytology, bronchial aspirate, bronchial biopsy, or percutaneous lung biopsy in 161 cases of confirmed primary lung cancer has been examined and the pretreatment histological diagnosis has been compared with the final diagnosis made after surgical resection or necropsy. The yield of positive diagnoses of malignancy obtained by each method of investigation in each cell type showed that cytological examination of sputum was the most accurate method, but a high degree of accuracy was also obtained by bronchoscopic aspiration and bronchial biopsy. Percutaneous lung biopsy was the most effective, but the least accurate, means of obtaining carcinoma cells. The level of diagnostic accuracy was highest in patients with squamous cell carcinoma. Accurate pretreatment diagnosis of patients with adenocarcinoma was particularly difficult, and only 20% of these cases were correctly diagnosed by investigation. Of seven patients with adenocarcinoma and a positive diagnosis of malignancy made on percutaneous lung biopsy, none was correctly diagnosed. The causes of error in diagnosis of cell type of primary lung cancer are discussed.

Adenocarcinoma↗