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Biomedical subjects

K Lerner

Publications and source records attributed to K Lerner.

6 recordsLinked to original sources
PubMed2001

Adenoviral brain-derived neurotrophic factor induces both neostriatal and olfactory neuronal recruitment from endogenous progenitor cells in the adult forebrain.

Neural progenitor cells persist throughout the adult forebrain subependyma, and neurons generated from them respond to brain-derived neurotrophic factor (BDNF) with enhanced maturation and survival. To induce neurogenesis from endogenous progenitors, we overexpressed BDNF in the adult ventricular zone by transducing the forebrain ependyma to constitutively express BDNF. We constructed a bicistronic adenovirus bearing BDNF under cytomegalovirus (CMV) control, and humanized green fluorescent protein (hGFP) under internal ribosomal entry site (IRES) control. This AdCMV:BDNF:IRES:hGFP (AdBDNF) was injected into the lateral ventricles of adult rats, who were treated for 18 d thereafter with the mitotic marker bromodeoxyuridine (BrdU). Three weeks after injection, BDNF averaged 1 microg/gm in the CSF of AdBDNF-injected animals but was undetectable in control CSF. In situ hybridization demonstrated BDNF and GFP mRNA expression restricted to the ventricular wall. In AdBDNF-injected rats, the olfactory bulb exhibited a >2.4-fold increase in the number of BrdU(+)-betaIII-tubulin(+) neurons, confirmed by confocal imaging, relative to AdNull (AdCMV:hGFP) controls. Importantly, AdBDNF-associated neuronal recruitment to the neostriatum was also noted, with the treatment-induced addition of BrdU(+)-NeuN(+)-betaIII-tubulin(+) neurons to the caudate putamen. Many of these cells also expressed glutamic acid decarboxylase, cabindin-D28, and DARPP-32 (dopamine and cAMP-regulated phosphoprotein of 32 kDa), markers of medium spiny neurons of the neostriatum. These newly generated neurons survived at least 5-8 weeks after viral induction. Thus, a single injection of adenoviral BDNF substantially augmented the recruitment of new neurons into both neurogenic and non-neurogenic sites in the adult rat brain. The intraventricular delivery of, and ependymal infection by, viral vectors encoding neurotrophic agents may be a feasible strategy for inducing neurogenesis from resident progenitor cells in the adult brain.

Adenoviridae↗
PubMed2000

Expression of alpha(v)beta6 integrin in oral leukoplakia.

The distribution of alpha(v)beta6 integrin was examined in oral leukoplakia, lichen planus and squamous cell carcinomas using immunohistochemistry. Controls included oral mucosal wounds, chronically inflamed and normal oral mucosa. Integrins beta1, beta3, beta4, beta5, fibronectin and tenascin were also studied. The integrin alpha(v)beta6 was highly expressed throughout the whole lesion of 90% of the squamous cell carcinomas but was not present in any of the normal specimens. alpha(v)beta6 integrin was also expressed in 41% of the leukoplakia specimens, and 85% of the lichen planus samples, but in none of the tissues with inflammatory hyperplasia or chronic inflammation. The expression of beta1 integrins was localized in the basal layer, and that of the beta4 at the cell surface facing the basement membrane of all specimens. The integrins beta3 and beta5 were absent from all normal and leukoplakia specimens. Fibronectin and tenascin were present in the connective tissue underneath the epithelium of all the sections, and their expression was similar in both alpha(v)beta6-positive and alpha(v)beta6-negative tissues. A group of 28 leukoplakia patients were followed 1-4 years after first diagnosis. In this group, initially alpha(v)beta6 integrin-positive leukoplakia specimens had high tendency for disease progression while alpha(v)beta6-negative specimens did not progress. These results suggest that the expression of alpha(v)beta6 integrin could be associated in the malignant transformation of oral leukoplakias.

Antibodies, Monoclonal↗
PubMed1996

Sweet's syndrome in a patient with oral cancer associated with radiotherapy.

Approximately 10-20% of the reported patients with acute febrile neutrophilic dermatosis (Sweet's syndrome) have an associated neoplasm. Oral findings of Sweet's syndrome are rarely reported, and no cases in patients with oral cancer have been reported to date. This report describes the clinico- and histopathological findings of Sweet's syndrome in a patient with oral cancer, treated with radiotherapy. After 10 fractions of external beam radiotherapy, treatment was interrupted because of severe oral mucositis which extended beyond the radiation fields. Two days later the patient developed multiple tender skin lesions and the diagnosis Sweet's syndrome was made. Skin and oral lesions resolved without additional treatment and did not recur upon resuming radiotherapy. As suggested in previous case reports, tumour antigens might play a role in the development of Sweet's syndrome. In this case, irradiation therapy may also have been a trigger for this syndrome.

Carcinoma, Squamous Cell↗
PubMed1988

Electron microscopic autoradiographic analysis: evidence of RNA transcription along pachytene chromosomes of rad-4, him-4 and wild-type Caenorhabditis elegans.

Decondensed chromatin regions have been described along the pachytene chromosomes of Caenorhabditis elegans (Goldstein, 1985). Regions of similar appearance, but not in pachytene chromosomes, have been shown to be transcriptionally active in other organisms (Angelier et al., 1979; Nagl, 1985). Incorporation of tritiated-uridine and electron microscopy autoradiography were utilized, in the present study, to determine if RNA transcription occurred along meiotic chromosomes of C. elegans. This study presents new evidence that RNA transcription occurs in highly defined regions along pachytene bivalents.

Animals↗