Biomedical subjects

J G Connolly

Publications and source records attributed to J G Connolly.

At least 19 recordsLinked to original sources

PubMed1992

Antibody drug carrier for immunotherapy of superficial bladder cancer: ultrastructural studies.

Superficial bladder cancer represents a promising target for intravesical, antibody-guided therapy. The construction of an optimum antibody-cytotoxic drug conjugate depends mostly on the appropriate selection of a monoclonal antibody (mAb). We have used immunogold labeling and SEM to specifically map the distribution of antigens expressed on three bladder cancer cell lines and on the luminal surface of biopsies from human transitional cell carcinoma of various grades and from normal bladder mucosa. The 48-127 mAb, which recognizes a M(r) 54,000 surface glycoprotein (gp54), was found to be very promising as a potential drug carrier. This antibody reacts with the surface of cells from low- and high-grade tumors; it does not react with the normal urothelium. Labeling of normal bladder mucosa was observed, however, on microvillous intermediate urothelial cells occasionally exposed by small areas of desquamation. The 48-127 mAb could target drugs to all areas of transformed urothelium while avoiding drug delivery to the normal, undesquamated bladder mucosa. Kinetics of gp54/48-127/gold complexes were tested in vitro with T24 and RT4 human bladder carcinoma cell lines incubated in the presence of the 48-127 mAb directly conjugated with 17.7-nm gold particles. Internalization of the gp54/48-127/gold complex was readily demonstrated by transmission electron microscopy. These results suggest that the 48-127 mAb represents a valuable drug carrier for intravesical therapy, allowing specific tumor targeting and internalization of various cytotoxic agents.

Aged↗

PubMed1992

The intestinoprostatic capsule anastomosis: functional and anatomic results in a canine model.

Because of its potential application to intestinal bladder reconstructions, the authors studied the functional and anatomic results of a modification of the Camey procedure. In this modification the enteric bladder replacement is sutured to the periphery of the prostatic capsule after the inner two-thirds of the prostate gland have been removed. In eight dogs postoperative functional studies revealed that all were continent and potent. Autopsy examination of the area of the intestinoprostatic anastomosis revealed that the prostatic fossa was lined by a transitional epithelial layer originating from the urethral stump and not by intestinal mucosa as might be expected. The results indicated that this modification is simpler technically than the original procedure, that it shortens the operating time and that it gives excellent functional results. If used in the context of bladder cancer, however, the procedure should be undertaken only in the presence of negative biopsies and brushings of the urethra before surgery, because the transitional epithelium lining the prostatic fossa represents a new area at risk later malignant transformation. Moreover, because of the potential importance of the area of prostatic fossa resurfaced postoperatively by urothelium, even patients with normal preoperative urethral biopsies and brushings who undergo such a procedure require careful follow-up with endoscopic examination, urethral biopsy and brushings and cytologic examination of the urine.

Anastomosis, Surgical↗

PubMed1991

Bladder cancer: long-term follow-up results of patients treated with radical radiation.

Carcinoma of the bladder is commonly treated for cure with external beam radiation. Whilst short-term results are associated with a good chance of disease control there is little information about the long-term results of such therapy. We present a retrospective review of the Princess Margaret Hospital experience in treating transitional cell carcinoma of the bladder and emphasis on the long-term follow-up of patients treated with radiotherapy (XRT). Between 1972 and 1980, 355 patients were treated with a radical course of external beam radiation. The overall survival was 20% at 10 years and the cause-specific survival was 32%. Radiation treatment resulted in a long-term bladder preservation in at least 25% of patients. The majority of long-term survivors without evidence of relapse were patients with T1 (solitary tumours), T2 and T3a tumours. This subgroup represents patients with disease favourable for treatment with radiation. Factors affecting response to the XRT and survival included T stage and tumour bulk. Radiation complications were frequent and were usually associated with local disease recurrence.

Adult↗

PubMed1990

Alpha 3, alpha 5, and beta 4: three members of the rat neuronal nicotinic acetylcholine receptor-related gene family form a gene cluster.

We have identified two additional members of the neuronal nicotinic acetylcholine receptor (nAChR)-related gene family. cDNA clones for one new gene, designated alpha 5, were isolated from rat hippocampus and rat PC12 cell line cDNA libraries. The alpha 5 gene encodes a protein of 48,800 daltons (424 amino acids) which exhibits significant overall amino acid sequence identity with the previously cloned rat nAChR subunits alpha 1 (49%), alpha 2 (55%), alpha 3 (52%), and alpha 4 (49%). Features characteristic of other nAChR alpha-subunits are present such as conserved cysteine residues at positions 127, 141, 191, and 192, and four strongly hydrophobic domains. A second addition to the nAChR-related gene family, designated beta 4, is encoded in overlapping rat genomic clones lambda DD15 and lambda RG518A. The beta 4 gene, encoding a mature protein of 53,300 daltons (475 amino acids), consists of 6 exons and has a transcription unit length of approximately 18 kilobase pairs. The beta 4 gene encoded protein shows considerable amino acid sequence identity with nAChR beta 1 (43%), beta 2 (64%), and beta 3 (44%) subunits. Northern blots showed that, along with alpha 3 and beta 2, transcripts for both the alpha 5 and beta 4 genes are present in the PC12 cell line, while in situ hybridization experiments demonstrated expression of the alpha 5 and beta 4 genes in a small number of nuclei in the central nervous system. Finally, the genes that encode the beta 4, alpha 3, and alpha 5 proteins are transcribed with convergent polarities and form a tightly linked gene cluster spanning approximately 60 kilobase pairs.

Amino Acid Sequence↗

PubMed1990

Scanning electron microscopy of immuno-gold labeled antigens associated with bladder cancer.

Scanning electron microscopy (SEM), in the backscattered electron imaging (BEI) mode, has been used to study the topographical distribution of colloidal gold labeled antigens expressed on the luminal surface of the bladder urothelium in biopsies from three categories of patients: 1) normal controls; 2) patients with a history of bladder cancer but no pathological diagnosis at time of cystoscopy; and 3) patients with overt transitional cell carcinoma (TCC) of various histopathological stages and grades. Cold cup biopsies were processed for immuno-SEM according to a previously described method. Antigens under investigation were: 1) ABH blood group antigens; and 2) those identified by the following murine monoclonal antibodies (mAbs): LEU-M1, T16, 19A211, G4 and E7. In most cases labeling patterns were correlated with the surface features of the superficial urothelial cells as revealed in the secondary electron imaging (SEI) mode of the SEM. Results, to date, indicate that the immuno-gold labeling method is more sensitive than immuno-peroxidase, and that phenotypic heterogeneity of antigenic expression (or deletion) is a frequent observation of potential diagnostic or prognostic value.

ABO Blood-Group System↗

PubMed1989

Structure-function relationships in nicotinic acetylcholine receptors.

1. A combination of molecular, biochemical, electrophysiological and immunological approaches has begun to resolve some of the questions about structure-function relationships of nicotinic acetylcholine receptors (AchRs). 2. Current structural studies suggest that models of the subunits which propose four transmembrane domains are correct. 3. It is also probable that the carboxy termini of the subunits are extracellular, while the putative amphpathic helix is intracellular. 4. Electrophysiological and ligand-binding experiments suggest that the M2 region forms the wall of the ion channel. 5. We have isolated clones from PC12 and rat brain cDNA libraries which we have shown, by functional expression, code for members of a gene family of nicotinic acetylcholine receptor subunits. 6. In situ hybridization studies have shown that the neuronal receptor subunit mRNAs are expressed in the mammalian central nervous system. 7. The muscle and neuronal nicotinic AchR subtypes we have expressed show differences in their pharmacological properties. 8. The isolation and identification of clones which code for receptors and voltage-activated ion channels will help in the understanding of a variety of disease states and assist in the design of drugs which are specific for unique molecular targets.

Acetylcholine↗

PubMed1989

Radical radiotherapy for muscle invasive transitional cell carcinoma of the bladder: failure analysis.

Patients with muscle invasive carcinoma of the bladder treated with radical radiation were prospectively documented and followed in an attempt to identify prognostic factors predictive of the response to treatment. Data on 121 consecutive patients treated with radical radiation between 1981 and 1985 are presented. Over-all actuarial survival of the patient population (median age 70 years) was 31.6% at 5 years and cause-specific survival was 44.8%. At analysis 33 of 121 patients (27.3%) were alive with preserved bladder function. Independent prognostic factors for cause-specific survival and for complete response with radical radiation were tumor configuration, hemoglobin level and clinical stage. The rate free of local relapse was significantly influenced by stage and presence of coexistent carcinoma in situ. The study suggests that factors other than stage and grade influence prognosis in invasive bladder cancer and should be considered in interpreting treatment results.

Adult↗

PubMed1987

Phenotypically heterogeneous deletion of the ABH antigen from the transformed bladder urothelium. A scanning electron microscope study.

The deletion of ABH blood group antigens from the luminal surface of the bladder mucosa in cases of well differentiated transitional cell carcinomata, and the formation of pleomorphic microvilli have both been associated with aggressive biological behaviour and invasiveness of the tumors. We have studied cold cup biopsies from 8 normal mucosae and 17 papillary transitional cell carcinomata of the urinary bladder. The aim of our study was to correlate the formation of uniform or pleomorphic microvilli with the extent of deletion of the ABH blood group antigens on the surface of normal and transformed bladder urothelium. Immunogold scanning electron microscopy (SEM) in the backscattered electron (BE) imaging mode was used for this purpose. In the normal urothelium, uniform labeling of the luminal cells was demonstrated. In well differentiated tumors, the superficial cells exhibited uniform microvilli and a heterogeneous expression of the ABH antigens, giving characteristic 'mosaic' patterns of the antigenic labeling across the mucosal surface. These patterns were sharply delimitated at cell junctions when viewed by SEM; these observations were confirmed by transmission electron microscopy. In higher grade tumors, decreased ABH antigen expression, pleomorphic microvilli and/or featureless luminal cells were observed. In the transformed urothelium, the formation of uniform microvilli appeared to precede the loss of ABH antigen in most cases.

ABO Blood-Group System↗

PubMed1986

A possible specific chromosome change in transitional cell carcinoma of the bladder.

Chromosome changes were ascertained in nine tumor samples from seven untreated patients with transitional cell carcinoma of the urinary bladder. All tumors analyzed showed abnormal karyotypes. In one tumor, a single numerical abnormality (+7) was the sole detectable change. From 1 to 19 structurally abnormal chromosomes could be identified in the remaining 8 tumors. The same abnormality, an isochromosome of the short arm of chromosome #5, was found in five tumors from four patients. We have previously described the presence of this marker chromosome in three of nine cases of transitional cell carcinoma of the bladder. We therefore conclude that i(5p) constitutes the most consistent nonrandom chromosome abnormality in this malignancy. Other chromosomes most frequently involved in structural changes in the present series of tumors were chromosomes #1, #6, #11, and #13.

Aged↗

PubMed1985

Changes in lipid fluidity and fatty acid composition with altered culture temperature in Tetrahymena pyriformis-NT1.

Cultures of T. pyriformis-NT1 were grown at 20 degrees C (Tg 20 degrees C) and 38 degrees C (Tg 38 degrees C). G.L.C. analysis and D.P.H. fluorescence polarization measurements in extracted phospholipids indicated that there was increased saturation of fatty acids and relatively reduced fluidity as growth temperature was increased. Breakpoints occurred in the Arrhenius plots of fluorescence polarization at 16 degrees C for Tg 38 degrees C total extracted phospholipids and 9 degrees C for Tg 20 degrees C lipids.

Animals↗

PubMed1985

The effects of temperature upon the electrophysiological properties of Tetrahymena pyriformis-NT1.

Cells of Tetrahymena pyriformis--NT1 were cultured at 38 degrees C (Tg 38 degrees C) and 20 degrees C (Tg 20 degrees C) and their properties investigated over the range 0-40 degrees C. Tg 20 degrees C cells were viable in the range 3-33 degrees C and changes in their properties were readily reversible between 10 degrees C and 30 degrees C. Tg 38 degrees cells were viable in the range 40-10 degrees C and their property changes were immediately reversible in the range 40-23 degrees C. The I-V relations of Tg 38 degrees C cells showed increased excitability as the cells were cooled from 40 degrees C. At 10 degrees C there was a considerable loss of excitability and slope resistance. Cooling Tg 20 degrees C cells from 20 degrees C gave a similar pattern, although over a narrower temperature range. Warming Tg 20 degrees C Tetrahymena above 20 degrees C led to a progressive loss of excitability and the cells were markedly less viable above 35 degrees C. Within physiological limits the regenerative spike magnitude, repolarization time, time to peak and input resistance increased as temperature was lowered, whereas resting potential was diminished. When compared at their growth temperatures and most intermediate temperatures, the value of the various parameters monitored were generally different for the two cultures. The Q10 value for resting potential changes of Tg 20 degrees C cells about 20 degrees C was 1.20. As in T. vorax this was significantly (P less than 0.01) greater than that predicted for a diffusion potential and suggested that T. pyriformis--NT1 may have an electrogenic pump component in its membrane potential.

Animals↗

PubMed1985

Temperature-dependent changes in the swimming behaviour of Tetrahymena pyriformis-NT1 and their interrelationships with electrophysiology and the state of membrane lipids.

The swimming velocity and the amplitude of the helical swimming path of T. pyriformis-NT1 cells grown at 20 degrees C (Tg 20 degrees C) and 38 degrees C (Tg 38 degrees C) were monitored between 0 and 40 degrees C in the presence and absence of electric fields. Within physiological limits the swimming velocity increased and the amplitude decreased as temperature was raised. The temperature profiles of these properties were not linear, and showed discontinuities at different temperatures for the different cultures. The break points in Arrhenius plots of the resting potential, regenerative spike magnitude, repolarization time, swimming velocity and swimming amplitude are tabulated and compared. The initial breakpoints upon cooling were clustered about the breakpoints in fluorescence polarization of D.P.H. in extracted phospholipids, and around the transition temperatures estimated from the literature for the pellicular membrane of these cells. The average of the initial breakpoints on cooling was 22.9 degrees C for Tg 38 degrees C cells and 13.7 degrees C for Tg 20 degrees C cells, a shift of 9.2 degrees C. Unlike Paramecium there is no depolarizing receptor potential in Tetrahymena upon warming. It is suggested that this may be the basis of a behavioural difference between Tetrahymena and Paramecium--namely that in Tetrahymena maximum swimming velocity occurs above growth temperature whereas in Paramecium the two points coincide. Swimming velocity and resting potential were correlated with membrane fluidity within physiological limits, but for other parameters the relationship with fluidity was more complex.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1979