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Biomedical subjects

J Morgan

Publications and source records attributed to J Morgan.

At least 199 records · Page 11Linked to original sources
PubMed1990

CAP 37, a 37 kD human neutrophil granule cationic protein shares homology with inflammatory proteinases.

We have previously shown that a major granule-associated cationic protein CAP 37 (Mr = 37 kD) derived from human PMN is a monocyte-specific chemoattractant. The N-terminal amino acid sequence of this novel chemotactic protein shares significant homology with a number of inflammatory molecules with protease activity including elastase and cathepsin G. However, a critical substitution of a serine for a histidine at position 41, results in its lack of serine protease activity.

Amino Acid Sequence↗
PubMed1990

Theoretical study of variables affecting the export of assimilates from branches of Picea.

A theoretical analysis was done to identify the features of conifer branch development, based on a model for Picea sitchensis (Bong.) Carr., that affect the ability to export assimilates, assuming (i) a branch's requirement for assimilates is determined by its need for mechanical support, and (ii) the production of assimilates is a simple function of total shoot length. There were three salient findings. First, there is an optimum and maximum shoot length for assimilate export by unbranched shoots. Second, the less a shoot extends itself each year, the more assimilate it may export, all else being equal. Third, there is a larger surplus of assimilates for export when a shoot develops laterals. A combination of lateral branching, deflection and decreased elongation can enable branches to continue growing and exporting assimilates for many years, as occurs at the bases of tree crowns.

Journal Article↗
PubMed1990

Comparison of a system of staff prompting with a programmable electronic diary in a patient with Korsakoff's syndrome.

The effect of a programmable electronic diary was compared with a system of staff prompting on the attendance at Occupational Therapy groups of a patient with Korsakoff's syndrome. Throughout the baseline period, the subject did not attend any groups. With the help of verbal prompting and other staff intervention, his attendance at groups increased significantly. By the fourteeth week he was attending all groups without verbal prompting apparently by using other environmental cues. The introduction of the electronic diary at this point was not found to increase the subject's attendance at groups further or to reduce the need for verbal prompting presumably due to a "ceiling effect". These findings suggest that despite severe memory impairment, the patient with Korsakoff's syndrome is able to learn new information. The potential of the electronic diary for reducing staff input and its use in a less predictable setting need to be evaluated further.

Alcohol Amnestic Disorder↗
PubMed1990

Activation of monocytic cells by monoclonal antibodies to the CD11a/18 (LFA-1) complex: mediation by Fc receptor.

IgG1 antibodies reacting with several monocytic antigens form a bridge between the specific antigen and the Fc receptors also expressed on these cells. This results in calcium mobilization and generation of superoxide. Single IgG1 antibodies reacting with the CD11a/CD18 cellular adhesion molecular complex do not, however, induce monocytic activation. This is not because they induce a negative signal, as the response to formyl-methionyl-leucyl2-phenylalanine (FMLP) or direct cross-linking of FcRII is not inhibited. Furthermore, a combination of an intact CD11a and CD18 antibody does induce a rise in intracellular calcium and production of superoxide. This activation is dependent on the binding of the Fc portion of both antibodies to Fc receptors, as F(ab')2 fragments do not cause activation. This suggests that simultaneous binding of opsonized bacteria to cellular adhesion molecules and to Fc receptors on monocytes would facilitate activation of these cells. Furthermore, it illustrates the importance of using F(ab')2 fragments in the analysis of signal transduction molecules on Fc receptor-bearing cells.

Antibodies, Monoclonal↗
PubMed1990

Crohn's disease of the appendix.

Crohn's disease limited to the appendix is uncommon. The disease may mimic acute appendicitis with fever, leukocytosis, right lower quadrant pain, and occasionally a palpable mass. When Crohn's disease affects the appendix, it typically has a longer clinical period in which the patient has symptoms than do most cases of acute appendicitis. The most common preoperative diagnoses are acute appendicitis and appendiceal abscess. A review of the literature is presented along with our experience in three additional cases of Crohn's disease limited to the appendix. We suggest that Crohn's disease be included in the preoperative differential diagnosis and that extensive intraoperative examination of the gastrointestinal tract be made in any case of suspected appendicitis that has had a protracted preoperative course.

Adolescent↗
PubMed1989

Enhanced fluorescence in indirect immunophenotyping by the use of fluorescent liposomes.

Small unilamellar liposomes were optimised for cell phenotyping by indirect immunofluorescence. This involved selection and covalent attachment to the liposome of a polyspecific ligand for cell-bound antibody. For this purpose sheep anti-mouse antibody was preferred to protein A because of its ability to attach to cell-bound IgG1 as well as IgG2 at physiological pH. The maximally fluorescent concentration of encapsulated carboxyfluorescein was determined to be 20 mM and liposomes thus comprised gave up to a nine-fold increase in mean cell fluorescence when compared with sheep anti-mouse antibody conjugated to fluorescein isothiocyanate. There was no parallel increase in background fluorescence. Liposomes retained their targeting and fluorescence properties after 3 months storage. They could be sterilised and were as versatile in use as FITC-antibody conjugates.

Animals↗
PubMed1989

Health care needs for children of the recently homeless.

Thirty families were surveyed at a shelter for the homeless in San Diego, California concerning the health care status and needs of their children. 56.7% of the families had no regular source of health care and 46.6% were not covered by any form of health coverage. Children whose families had a regular source of health care were more likely to have reported better health and more frequent checkups. Also, increased duration of homelessness was predictably correlated with poorer reported health of the children. Though the families sampled were representative of those recently made homeless i.e. less than six months, needs were identified that would be applicable to all homeless families. The most frequent needs the families expressed for their children were: general nonemergency clinics (76.7%), emergency services (66.7%), and dental services (66.7%). Nutritional and dietary counseling were chosen by 43.3% and only 6.7% of the parents rated social and psychological services as needed.

Adult↗
PubMed1989

Characterization of novel populations of MVM virions containing covalent DNA-protein complexes.

Virions of minute virus of mice were purified by sedimentation in sucrose gradients and chromatography on DEAE-cellulose columns and shown to consist of single-stranded viral DNA and the viral capsid polypeptides VP-1 (83 kDa) and VP-2 (64.5 kDa). A 63-kDa polypeptide distinct from the viral capsid polypeptide VP-3 (61.4 kDa) was found in some virion preparations. Virions sedimented at 135 and 110 S. The genomic single strands associated with purified 135 and 110 S virions were covalently bound to a protein as judged by the anomalous electrophoretic mobility of the DNA in agarose gels at pH 12.5. The protein was removed from the DNA by Pronase but remained bound after heating at 98 degrees in the presence of 0.1% sodium dodecyl sulfate. Nuclease digestion of the purified DNA-protein complex released several polypeptides ranging in size from 58 to 65 kDa. Restriction enzyme analysis of the purified DNA protein complex following its conversion to a duplex RF DNA in vitro showed that the protein was attached to the 5' termini of the DNA.

Animals↗
PubMed1989

Comparison of the efficacy of surgery and acyclovir therapy in oral hairy leukoplakia.

To compare the therapeutic effects of surgical excision and orally administered acyclovir therapy on symptomatic oral hairy leukoplakia, 45 homosexual men who were seropositive for human immunodeficiency virus participated in a 3-month open-label study. In the 14 patients who had surgical excision, pain resolved in four symptomatic patients and the leukoplakia did not recur in the areas of excision. New foci of leukoplakia, however, appeared in 10 patients after 3 months. Of the 16 patients who received acyclovir therapy, 12 had a clinical regression, although recurrences were noted in all patients after 3 months. Three patients had resolution of pain while taking acyclovir; in two the pain recurred after acyclovir was discontinued. No spontaneous remissions of the leukoplakia occurred in the 15 patients who refused therapy. We conclude that surgical excision is effective in patients with symptomatic oral hairy leukoplakia.

Acyclovir↗
PubMed1989

Specific targeting and toxicity of sulphonated aluminium phthalocyanine photosensitised liposomes directed to cells by monoclonal antibody in vitro.

A partially purified fraction of the water soluble photosensitive dye sulphonated aluminium phthalocyanine (AlSPc) was encapsulated in liposomes which were then linked to a targeting monoclonal antibody 791T/36 using a heterobifunctional linking agent. The photocytotoxic effects of the liposomes were determined on two cell lines bearing an antigen with which the targeting antibody binds: 791T, an osteosarcoma and C170, a colorectal carcinoma; and a control cell line not bearing the antigen; DW-BCL, an Epstein-Barr virus immortalised B-cell line. Antibody dependent cytotoxicity was observed in 791T and C170 cells and was proportional to the number of antigens on the cells, the AlSPc concentration and the time of exposure to activating red light. No significant toxicity was seen using untargeted liposomes, control cells or free AlSPc fraction under similar conditions. Targeted cells and controls kept in the dark also showed no significant toxicity. A possible mechanism of action is postulated and simple adaptations which demonstrate the versatility of the model are discussed. Some suggestions as to the clinical situations to which this system might be applied in the form of photodynamic therapy (PDT) are made.

Antibodies, Monoclonal↗
PubMed1989

Branch breakage under snow and ice loads.

Measurements were made on branches and trunks of Picea sitchensis (Bong.) Carr. to determine the relationship between (i) the bending moment at the bases of branches that cause breakage, and (ii) midpoint diameter cubed. The theory for cantilever beams was then used to calculate the basal bending moments and midpoint diameters of branches with different numbers of laterals and endpoint deflections, given previously measured values of Young's modulus, taper and weights of foliage and wood. Snow and ice loads (equal to 2 and 4 g cm(-1) of shoot, respectively) were then included in the calculation to determine whether the basal bending moments exceeded the breakage values. The likelihood of breakage increased with an increase in (i) number of laterals, and (ii) endpoint deflection under self weight (without snow or ice)-features that had previously been shown to lessen the amount of branch wood required to support a unit of foliage. However, branches which deflected moderately (> 10% of their length) under their own weight deflected greatly under snow or ice loads and might shed powdery snow before breakage occurs.

Journal Article↗
PubMed1989

Malignant endovascular papillary angioendothelioma (Dabska tumor). A case report and review of the literature.

Malignant endovascular papillary angioendothelioma is a rare vascular tumor of childhood that was first defined by Dabska in 1969. Microscopically, this tumor is composed of anastomosing vascular channels, some of which contain papillary projections or tuft-like structures sometimes resembling renal glomeruli. Although cases have been reported with metastases to regional lymph nodes, the long term prognosis for patients with these tumors is generally good. We have studied this tumor by light and electron microscopy as well as immunohistochemical techniques in a 10-year-old boy. A review of the literature on this rare entity is presented.

Back↗
PubMed1989

Isolation of mucoid strains of Pseudomonas aeruginosa from non-cystic-fibrosis patients and characterisation of the structure of their secreted alginate.

When the incubation period of primary isolation plates was extended to 48 h, mucoid strains of Pseudomonas aeruginosa were found in specimens from various infected sites in patients who did not have cystic fibrosis. The 17 mucoid isolates were characterised in terms of mucoid type, pyocin type, and their sensitivity or resistance to seven beta-lactam and two aminoglycoside antibiotics. The carbohydrate, uronic acid (alginate) and protein content of the water-soluble extracellular material of 15 strains was determined. This material was fractionated by ion-exchange chromatography, and the presence of alginate confirmed by the chemical assay of uronic acids and their quantitation by gas-liquid chromatography. Uronic acids were absent from a non-mucoid revertant of one strain. The strains produced alginate with a high content of mannuronic acid and substituted with O-acetyl groups. By proton nuclear magnetic resonance (1H-nmr) analysis the alginate from three strains was shown to lack polyguluronate blocks in its structure. These properties are also found in the alginate of mucoid P. aeruginosa strains from patients with cystic fibrosis.

Alginates↗
PubMed1989

Negative modulation of Epstein-Barr virus episomes by a human B-cell growth factor.

To study the effect of T-cell-derived BCGF-12kD on human B-cell autocrine growth-associated functions, we cultured Epstein Barr virus (EBV)-transformed normal B cells (LCL 72285) and Burkitt's lymphoma cells (Raji) in the presence or absence of BCGF-12kD. When cultured in media supplemented only with fetal calf serum, the LCL and Raji cell lines maintained relatively high levels of episomes. Although a similar level of proliferation could be maintained under defined culture conditions in media supplemented with BCGF-12kD, these conditions resulted in a time-dependent reduction of EBV sequences, as detected with EBV nuclear antigen (EBNA-1 and EBNA-2) gene probes. These results suggest that stimulation with T-cell-derived BCGF-12kD can alter a regulatory step which may be involved in the EBV transformation of B cells.

B-Lymphocytes↗
PubMed1989

Double-blind randomized cross-over trial of dexamethasone and prochlorperazine as anti-emetics for cancer chemotherapy.

A double-blind randomized cross-over trial of dexamethasone and prochlorperazine as adjunctive anti-emetics with cancer chemotherapy was undertaken. The drugs were compared for cisplatin, doxorubicin and several other chemotherapy regimens. A total of 44 eligible patients were analysed. Assessment was made by questionnaire answered by the patient 24 h after the chemotherapy. The parameters compared were period of time for nausea and vomiting, number of vomiting episodes, degree of somnolence and insomnia and overall preference. In all cases there was no significant difference for either drug in its ability to suppress emetic effects. Neither drug gave adequate protection against cisplatin-containing regimens. We conclude that dexamethasone alone is equivalent to the more standard dopamine antagonists.

Adult↗
PubMed1989

Generation and characterization of monoclonal antibodies specific for the human neu oncogene product, p185.

A series of monoclonal antibodies specific for the extracellular domain of the human neu gene product (p185) have been produced. The generation of these monoclonal antibodies, and their biochemical and immunological characterization is described. The immunization protocol utilized a series of injections of NIH3T3 cells, cyclophosphamide, and a neu transfected NIH3T3 cell line (designated 18-3-7) which expressed the full length human neu-encoded protein. This immunization regimen induced an immune response to the extracellular portion of p185 on the 18-3-7 cells. A panel of ten hybridomas were identified which secreted monoclonal antibodies with a variety of epitope specificities, and reacted with p185 in a number of different experimental formats. As the neu gene product has been associated with human breast cancers, a series of monoclonal antibodies such as these could prove useful in the diagnosis, prognosis and/or treatment of these human malignancies.

Animals↗