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Biomedical subjects

B A Morris

Publications and source records attributed to B A Morris.

At least 19 recordsLinked to original sources
PubMed1992

The nucleotide sequence of the infectious cloned DNA component of tobacco yellow dwarf virus reveals features of geminiviruses infecting monocotyledonous plants.

An infectious clone of the Australian geminivirus tobacco yellow dwarf virus (TobYDV) was constructed from virus-specific double-stranded DNA isolated from infected tobacco and used to demonstrate a single-component genome. The nucleotide sequence of TobYDV DNA comprises 2580 nucleotides. TobYDV DNA has three coding regions, two in the virion sense and one in the complementary sense, homologous to those identified for other geminiviruses, particularly those infecting monocotyledonous (monocot) plants. The complementary sense coding region is comprised of two overlapping reading frames, with an intron of 86 nucleotides. Efficient splicing of the mRNA for this coding region was observed in the infected dicotyledonous (dicot) hosts bean and tobacco despite the intron having an A + U content (57%) more typical of geminiviruses of monocot plants. TobYDV encapsidates a small oligonucleotide able to prime synthesis of the complementary DNA strand in vitro. The TobYDV genome organization, low A + U intron, and encapsidated oligonucleotide primer resemble those of the monocot-infecting geminiviruses. These results strongly suggest that TobYDV is a monocot geminivirus which has become adapted to dicot hosts.

Base Sequence↗
PubMed1992

Nucleotide sequences and expression of cDNAs for a bovine anti-testosterone monoclonal IgG1 antibody.

cDNAs coding for the heavy and light chains of a bovine anti-testosterone IgG1 monoclonal antibody have been cloned and sequenced. These cDNAs are the first to be reported for functionally rearranged bovine immunoglobulin genes. Testosterone binding by the antibody encoded by the cDNAs has been verified by expression of the cDNAs in COS-1 cells and detection of anti-testosterone antibodies in transfected cell media using an ELISA specific for bovine anti-testosterone IgG. The derived protein sequence of the variable domains have suggested a possible binding model for the interaction between the antibody and testosterone. The derived protein sequence of the constant domains has been used to identify residues which could be involved in the selective transport of bovine IgG1 from blood plasma into colostrum at the time of parturition.

Amino Acid Sequence↗
PubMed1992

Molecular modelling and site-directed mutagenesis on a bovine anti-testosterone monoclonal antibody.

A three-dimensional (3D) molecular model of the antigen-combining site of a bovine anti-testosterone monoclonal antibody has been constructed. In the model, the CDRs, and a single heavy chain framework region residue (Trp47), associate to form a hydrophobic cavity large enough to accommodate a single molecule of testosterone. Tyr97 of CDR-H3 lies at the bottom of the cavity with its hydroxyl group exposed to solvent. Using the model and data from binding studies, we predicted that the cavity forms the antibody's paratope and on binding testosterone a hydrogen bond is formed between Tyr97 of CDR-H3 and the hydroxyl group on the D-ring of testosterone. This prediction has subsequently been tested by site-directed mutagenesis. An antibody with phenylalanine in place of tyrosine at position 97 in CDR-H3 has its affinity reduced by approximately 800 fold. The reduction in binding energy associated with the reduced affinity has been calculated to be 3.9 kcal/mol which is within the range (0.5-4.0 kcal/mol) expected for the loss of a single hydrogen bond. The model has been used to suggest ways of increasing the antibody's affinity for testosterone.

Amino Acid Sequence↗
PubMed1992

The influence of continuous passive motion on the results of total knee arthroplasty.

Twenty-two primary total knee arthroplasties were prospectively randomized into one of two treatment protocols. Ten of these patients were managed in the hospital after surgery by means of a postoperative splint. The remaining 12 patients were placed immediately postoperatively in the recovery room into the continuous passive motion (CPM) device. The study compares the range of motion, analgesic use, hospital stay, and the volume of hemovac output in the two groups. These cases demonstrated two statistically significant findings with the use of CPM: (1) decreased use of narcotic analgesics and (2) decreased length of hospital stay.

Aged↗
PubMed1992

Community and university--partners in research.

Community-based and university-based family practice researchers must come together and merge into a synergistic partnership. Community-based researchers often need the special expertise of university statisticians, epidemiologists, and research methodologists, and the enthusiasm of fellow researchers. University-based researchers look to the community for subjects and the all-important factor of generalizability. We must no longer rely on serendipity to bring community- and university-based researchers together. Community-based people must acknowledge their needs and actively seek out assistance. The university-based departments can respond by deliberately starting outreach programs, setting up buddy systems, engaging community research consultants, and tracking residents and urging them to continue to do research. Sentinel networks can increase the depth of involvement community researchers have with their own, and others', projects. Such efforts will lead to a creative interrelationship that will be rewarding and enjoyable for us all.

Family Practice↗
PubMed1991

Postoperative use of continuous passive motion, transcutaneous electrical nerve stimulation, and continuous cooling pad following total knee arthroplasty.

Three rehabilitation modalities relating to in-hospital postoperative care following unilateral total knee arthroplasty (UTKA) were studied regarding their effect on pain management and UTKA outcome: (1) continuous passive motion (CPM); (2) CPM with transcutaneous electrical nerve stimulation (TENS); and (3) CPM with continuous cooling pad (CCP). Phase I: CPM. Twenty-two UTKA patients were randomized into two postoperative care groups: (1) 12 with CPM; and (2) 10 with no CPM. Total hospitalization pain medication consumption was significantly less for the CPM group (P less than .05). Phase II: CPM With TENS. Forty-eight UTKA patients were randomized into three postoperative care groups: (1) 18 with an ipsilateral thigh TENS unit delivering sensory threshold stimulation; (2) 18 with a subthreshold TENS unit; and (3) 12 with no TENS unit. All groups used CPM. No significant difference was found regarding pain medication consumption. Phase III: CPM With CCP. Thirty consecutive UTKA patients were divided into two postoperative care groups: (1) 15 with a CCP unit; and (2) 15 with no CCP unit. Both groups used CPM. No significant difference was found regarding total or intramuscular hospitalization pain medication consumption. However, oral hospitalization pain medication consumption was significantly less for the CCP group (P less than .01). This postoperative UTKA study demonstrates significantly decreased total in-hospital pain medication consumption when comparing CPM vs no CPM, significantly decreased oral in-hospital pain medication consumption when comparing CPM with CCP vs CPM without CCP, but no difference when comparing CPM with TENS vs CPM without TENS.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

The detection of an early advanced glycation product which co-elutes with the Amadori product on aminophenylboronate affinity chromatography.

The production of an antiserum recognizing an early advanced glycation product of glycated human serum albumin (HSA) is reported. The antiserum was produced with the intention of recognizing the Amadori product, i.e. the monofructosamine derivative, of any glycated protein. In retrospect, however, the immunogen appears to have been transformed in vivo which led to the production of antibodies to an early advanced glycation product. Two-site immunometric and competitive ELISAs showed that the affinity-purified antibodies recognized glycated HSA only after it had been stored for several months. This recognition, by the antibody, was more specific for the transformed product than for the original hapten (1-amino-1-deoxy-D-fructose-6-aminohexanoic acid) used for immunization by a factor of more than 1,000. These antibodies also detected immunoreactive material present in the elution fraction after in vivo glycated HSA had been chromatographed on an aminophenylboronate affinity column, indicating that an early advanced glycation product can co-elute with the Amadori product of glycated HSA on aminophenylboronate affinity chromatography. This suggests that the antiserum recognized an early advanced glycation product that also contained cis-diols as does the Amadori product, and may prove useful in the early detection of clinical complications in diabetic patients.

Aminocaproic Acid↗
PubMed1990

The preparation of an ovine monoclonal antibody to progesterone.

Peripheral blood mononuclear cells were collected from a sheep immunized against progesterone-11 alpha-hemisuccinate-ovalbumin. Following fusion with NS1 mouse myeloma or heteromyeloma cells, a large number of hybrid colonies was established. These were screened for the production of sheep antibodies to progesterone. Twenty-four cell lines were cloned and one was stabilized. This cell line, O/MP.1A9.D7B2, produced a high-affinity ovine immunoglobulin G1 (dissociation constant 4.8 pmol/l) with a high degree of specificity for progesterone. The antibody was substituted into a competitive enzyme-linked immunosorbent assay for the measurement of progesterone in bovine milk, originally established using an ovine polyclonal antibody, and the results were compared. The monoclonal antibody produced an assay with a lower limit of detection and a greater degree of discrimination than the polyclonal antiserum.

Animals↗
PubMed1990

Pharmacokinetic studies of passively administered ovine anti-testosterone antibodies given to cattle by the subcutaneous and intravenous routes.

Passive immunization of cattle with ovine anti-testosterone antiserum can result in an increased ovulation rate, but the effect is variable and may be influenced by the route of administration. Investigations were made into the pharmacokinetics of these antibodies in cattle when given intravenously (i.v.), subcutaneously (s.c.) or via a combination of these two routes. Serum levels of free residual binding sites were measured by testosterone radioimmunoassay, whilst total circulating ovine IgG was determined using a specific enzyme-linked immunosorbent assay which shows no cross-reactivity with bovine IgG. The biological half-life of the administered antibodies was longer when it was calculated by measuring titre than when it was calculated by measuring IgG. Subcutaneous injection resulted in a significantly longer half-life of IgG than intravenous injection or the combined route, with a concomitant increase in the area under the curve. No significant differences between the half-lives as measured by titre were noted following the various routes of administration, but the mean value following s.c. injection was longest. The choice of route of administration of antiserum for passive immunization can be used to control the timing and duration of effective antibody levels. The results of the present study suggest that the s.c. or combined i.v. and s.c. routes are the preferred methods of passive immunization if an effect of long duration is required. It may be that it is the period over which the maximum level is maintained, rather than the absolute maximum level, which is important for successful immunomodulation of ovulation rate.

Animals↗
PubMed1988

Nucleotide sequence of the geminivirus chloris striate mosaic virus.

The genome of chloris striate mosaic virus (CSMV) comprises a single circular DNA as determined by analyses on virion single-stranded (ss) DNA and virus-specific covalently closed circular (ccc) DNA isolated from infected plants. The nucleotide sequence of CSMV DNA was determined from cccDNA and the data were accommodated into one DNA circle of 2750 nucleotides. Comparison of the nucleotide sequence with those of maize streak virus (MSV), wheat dwarf virus (WDV), and digitaria streak virus (DSV) showed 49, 47, and 48% DNA homology, respectively. The sequence has four potential open reading frames for proteins of greater than 10,000 mol wt, two in the viral (+) sense and two in the complementary (-) sense. Three of these potential coding regions have homologous counterparts, by comparison of the amino acid sequences, among the open reading frames reported for MSV, WDV, and DSV. CSMV encapasidates primer molecules able to prime the synthesis in vitro of a complementary strand to virion DNA, initiating this reaction at one site on the genome. The CSMV primer comprising approximately 88 nucleotides was located within the smaller of two intergenic or noncoding regions.

Base Sequence↗
PubMed1988

A bovine monoclonal antibody to oestrone/oestradiol prepared by a (murine x bovine) xbovine interspecies fusion.

A heterohybridoma was produced by the fusion of sensitized peripheral blood lymphocytes (PBLs) with a previously derived heteromyeloma, generated by the fusion of bovine PBLs with murine myeloma cells. The sensitized bovine PBLs were collected from a steer immunized with an oestradiol-ovalbumin conjugate. The cell lines resulting from the fusion were screened for the production of bovine antibodies to oestradiol. A stable heterohybridoma was isolated which secreted a bovine IgG1 to oestrone/oestradiol. The use of sensitized PBLs together with heteromyeloma fusion partners has proved to be a reliable and simple way of producing monoclonal antibodies against specific haptens.

Animals↗
PubMed1988

Induction of the rat hepatic microsomal mixed-function oxidases by 3 imidazole-containing antifungal agents: selectivity for the cytochrome P-450IIB and P-450III families of cytochromes P-450.

Administration of the imidazole antifungal agents ketoconazole, miconazole and clotrimazole gave rise to increases in the microsomal cytochrome P-450 levels and the NADPH-dependent reduction of cytochrome c. Clotrimazole, and to a much lesser extent miconazole and ketoconazole, stimulated the dealkylation of pentoxyresorufin. All 3 agents gave rise to small, but significant increases in the O-deethylation of ethoxycoumarin and ethoxyresorufin. The antifungal-induced O-deethylation of ethoxycoumarin was much more sensitive to inhibition by metyrapone rather than by alpha-naphthoflavone. The binding of metyrapone to reduced microsomes was enhanced by treatment of animals with the 3 antifungal agents, clotrimazole being clearly the most potent. Immunoquantitation of cytochrome P-450 proteins using an ELISA procedure and employing anti-cytochrome P-450c (P-450IA1, P-448 low spin) and P-450b (P-450IIB1) antisera revealed that clotrimazole and miconazole, but not ketoconazole, induced the levels of phenobarbital-induced cytochromes P-450, while none of the antifungal agents increased the levels of cytochrome of P-448 proteins. Similar results were obtained using Western blots employing the above antibodies. On SDS-polyacrylamide gel electrophoresis microsomes derived from animals pretreated with clotrimazole showed intensification of a band at 51 kDa which was identified by Western blotting as the PCN-inducible form of cytochrome P-450 (cytochrome P-450p, P-450III family). Similar, but less pronounced intensification was seen with microsomes from animals pretreated with miconazole and ketoconazole. Furthermore, microsomes from clotrimazole- and ketoconazole-treated animals interacted with erythromycin to yield type I spectra. It is concluded that the imidazole-containing agents clotrimazole and miconazole, and to a much lesser extent ketoconazole, are potent inducers of the rat hepatic microsomal mixed-function oxidases, displaying selectivity towards the P-450IIB (phenobarbital-inducible) and P-450III (PCN-inducible) families of cytochrome P-450 proteins.

Animals↗
PubMed1988

Acrocyanosis due to imipramine.

An 11 year old girl who was being treated for enuresis with imipramine developed acrocyanosis of the hands and feet. All biochemical and haematological investigations gave normal results. When imipramine was stopped the girl recovered within three days.

Adolescent↗