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Biomedical subjects

F Lee

Publications and source records attributed to F Lee.

At least 253 records · Page 14Linked to original sources
PubMed1987

Simultaneous microdialysis and amphetamine infusion in the nucleus accumbens and striatum of freely moving rats: increase in extracellular dopamine and serotonin.

To test the effects of systemic and local amphetamine on dopamine and serotonin release in freely moving rats, guide cannulas were implanted in the nucleus accumbens and ventral striatum for removable 200 mu microdialysis probes. Comparing 45 min samples before and after IP amphetamine (2 mg/kg), dopamine (DA) in dialysate from the accumbens increased from a baseline of 3 pg/20 microliters to 11 pg/20 microliters whereas dopamine metabolites, DOPAC and HVA decreased. This was probably due to block of DA reuptake and inhibition of monoamine oxidase, MAO. Accumbens serotonin increased from a baseline of 8 to 11 pg/20 microliters. Changes in the ventral striatum were similar. In the second experiment, microdialysis was performed before and after local injection of amphetamine (4 micrograms) to reveal effects of amphetamine in the terminal area only instead of the whole brain. DA in the accumbens increased from 11 to 147 pg per sample; serotonin, from 11 to 107. The effect was even larger in the ventral striatum. DA increased from 12 to 409 pg/20 microliters; serotonin, 3 to 139. To avoid handling the rat or disturbing brain tissue in experiment three, amphetamine was infused via the microdialysis probe during ongoing dialysis sampling. Perfusate containing amphetamine was switched into the flow line which allowed roughly 10% or 4 micrograms to diffuse out into the extracellular space. During this 20 min, extracellular DA in the accumbens increased from a baseline of 10 pg/20 microliters to 300 pg/20 microliters sample. Serotonin increased from barely detectable to 60 pg/20 microliters. DOPAC decreased significantly; HVA and 5HIAA drifted lower.(ABSTRACT TRUNCATED AT 250 WORDS)

3,4-Dihydroxyphenylacetic Acid↗
PubMed1987

Detection of antibodies to herpes simplex virus in the cerebrospinal fluid of patients with herpes simplex encephalitis.

Cerebrospinal fluid (CSF) and serum specimens from patients with presumed herpes simplex encephalitis (HSE) were characterized for antibodies to herpes simplex virus (HSV) by immunoblot and other immunoassays. Specimens from patients proven to have HSE (biopsy-proven) were compared with those from patients with other diseases diagnosed by brain biopsy (biopsy-negative for HSV). Immunoblot of CSF demonstrated that antibodies to HSV-specific polypeptides, particularly to glycoprotein B, were present in a matched serum specimen. When purified glycoprotein B was used to detect CSF antibodies, 34 of 35 specimens from biopsy-proven patients were reactive (97% sensitivity) compared with only six of 22 specimens obtained from biopsy-negative patients (73% specificity). If leakage of antibodies to a marker virus (adenovirus) was determined and controlled, the specificity increased to 100%. These diagnostic assays provide useful tools for the retrospective assessment of CSF specimens obtained from patients with presumed HSE.

Adolescent↗
PubMed1987

Needle aspiration and core biopsy of prostate cancer: comparative evaluation with biplanar transrectal US guidance.

Biplanar, transrectal ultrasound (US) guidance of needles was used in the transperineal biopsy of possibly malignant prostatic lesions in 80 patients (83 biopsies). A 22-gauge cytologic needle was used to locate and fixate the lesion, and aspiration specimens for cytologic and histologic evaluation were obtained (with 22- and 14-gauge needles, respectively). Twenty-one 19-gauge needle core biopsies were also performed. Forty-nine patients (61%) had histologically prove adenocarcinoma. The rate of cancer diagnosis was 53% with cytologic evaluation and 54% with histologic evaluation (combined yield, 61%). This included 34% of cancers less than 1.0 cm in diameter and 56% of those 1.0-1.5 cm. Thirteen of 23 (57%) of these lesions were nonpalpable or equivocal on digital rectal examination. These results suggest that transrectal US guidance of thin-needle biopsies is useful in diagnosing early prostate cancer.

Adenocarcinoma↗
PubMed1987

Control of hemopoiesis by a bone marrow stromal cell clone: lipopolysaccharide- and interleukin-1-inducible production of colony-stimulating factors.

A stromal cell line, GY30, was cloned from mouse bone marrow adherent cell layers. In culture, GY30 cells sustain the production of granulocyte-macrophage progenitor cells (GM-CFU) but fail to support the survival of pluripotential stem cells (CFU-S). GY30 cells secrete two growth factor activities distinct from interleukin-3 (IL-3), IL-2, and macrophage colony-stimulating factor (M-CSF) but functionally similar to GM-CSF and G-CSF. The production of both CSFs is increased 70- to 200-fold by treating GY30 cells with lipopolysaccharide or IL-1. RNA blot analysis reveals the presence of GM-CSF and G-CSF transcripts and demonstrates that IL-1 regulates the production of both factors at the mRNA level. Further, these studies show that the GM-CSF secreted by GY30 cells is structurally similar to the GM-CSF produced by activated T cells.

Animals↗
PubMed1986

Isolation and characterization of a human interleukin cDNA clone, homologous to mouse B-cell stimulatory factor 1, that expresses B-cell- and T-cell-stimulating activities.

A cDNA sequence coding for a human interleukin has been isolated from a concanavalin A-activated human T-cell cDNA library based on homology with a mouse interleukin cDNA that expresses B-cell stimulatory factor 1 (BSF-1) activity and T-cell- and mast-cell-stimulating activities. The human cDNA contains a single open reading frame encoding a protein of 153 amino acid residues including a putative signal peptide. Amino acid sequences of the mouse and human polypeptides, deduced from their cDNAs, share extensive homology with the exception of about 40 amino acid residues near the middle portion, which share little homology. Supernatant of COS-7 monkey cells transfected with the human cDNA clone stimulated proliferation of human helper T-cell clones and of anti-IgM-activated human B cells, two properties of mouse BSF-1 on mouse cells. These results indicate that this human cDNA clone encodes a protein structurally and functionally homologous to mouse BSF-1.

Amino Acid Sequence↗
PubMed1986

Isolation and characterization of a mouse interleukin cDNA clone that expresses B-cell stimulatory factor 1 activities and T-cell- and mast-cell-stimulating activities.

A cDNA sequence coding for a unique mouse interleukin that expresses B-cell-, T-cell, and mast-cell-stimulating activities has been isolated from a mouse helper T-cell cDNA library. The library, constructed in the pcD expression vector, was screened by transfecting COS monkey cells with DNA pools to express the products encoded by full-length cDNA inserts. By assaying the transfected cell supernatants, we identified clones encoding a factor that stimulates T-cell and mast cell lines. This factor also induces Ia expression on resting B cells and enhances IgG1 and IgE production by B cells, two properties of B-cell-stimulatory factor 1. The DNA sequence codes for a polypeptide of 140 amino acid residues including a putative signal peptide. These results demonstrate that a single cDNA clone distinct from interleukin 2 and interleukin 3 encodes a polypeptide with multiple biological activities.

Amino Acid Sequence↗
PubMed1986

Prostatic evaluation by transrectal sonography: criteria for diagnosis of early carcinoma.

Over a 7-month period, from a total of 417 transrectal ultrasound (US) studies, 45 transperineal biopsies of the prostate were performed in the radiology department. Transrectal US guidance and local anesthesia were used. Twenty-two of 32 hypoechoic lesions, located within the peripheral zone tissue of the gland, were proved by histologic study to be cancerous. Hyperechoic lesions were all histologically benign hyperplasias. The patients experienced no major complications necessitating hospitalization or increased length of hospital stay as a result of the procedure.

Adult↗
PubMed1985

Structure of the chromosomal gene for granulocyte-macrophage colony stimulating factor: comparison of the mouse and human genes.

A cDNA clone that expresses granulocyte-macrophage colony stimulating factor (GM-CSF) activity in COS-7 cells has been isolated from a pcD library prepared from mRNA derived from concanavalin A-activated mouse helper T cell clones. Based on homology with the mouse GM-CSF cDNA sequence, the mouse GM-CSF gene was isolated. The human GM-CSF gene was also isolated based on homology with the human GM-CSF cDNA sequence. The nucleotide sequences determined for the genes and their flanking regions revealed that both the mouse and human GM-CSF genes are composed of three introns and four exons. The organization of the mouse and human GM-CSF genes are highly homologous and strong sequence homology between the two genes is found both in the coding and non-coding regions. A 'TATA'-like sequence was found 20-25 bp upstream from the transcription initiation site. In the 5'-flanking region, there is a highly homologous region extending 330 bp upstream of the putative TATA box. This sequence may play a role in regulation of expression of the GM-CSF gene. These structures are compared with those of different lymphokine genes and their regulatory regions.

Amino Acid Sequence↗
PubMed1985

Transrectal ultrasound in the diagnosis of prostate cancer: location, echogenicity, histopathology, and staging.

Adenocarcinoma of the prostate produces specific ultrasonic findings that can be used in diagnosis. We have examined 211 patients using transrectal ultrasound in both the sagittal and axial planes. Thirty-three carcinomas were detected, and 31 histologically confirmed; 24 by needle biopsy, six by transurethral resection, one by total prostatectomy, and two by the demonstration of distant metastases. On ultrasound, all of the carcinomas were less echogenic than normal prostate. All appeared to originate in the peripheral zone of the prostate and produced asymmetry of the gland. The majority of carcinomas in this series showed capsular involvement and ten penetrated and extended beyond the prostatic capsule. The results of this series indicate that transrectal ultrasound can be used to detect cancer of the prostate gland. Ultrasound demonstrated the extent of tumor involvement and enabled accurate staging of these cancers.

Adenocarcinoma↗