PubMed Health⌕ Search

Biomedical subjects

M Garner

Publications and source records attributed to M Garner.

At least 19 recordsLinked to original sources
PubMed2001

mei-41 and bub1 block mitosis at two distinct steps in response to incomplete DNA replication in Drosophila embryos.

Drosophila double park encodes a homolog of Cdt1 that functions in initiation of DNA replication in fission yeast and Xenopus. dup mutants complete the first 15 embryonic cell cycles, presumably via maternal dup products, and show defects in the 16(th) S phase (S16). Cells carrying dup(a1) allele forgo S16 altogether but enter mitosis 16 (M16). We find that the timing of entry into M16 is similar in dup(a1) and heterozygous or wild-type (wt) controls. In contrast, we find that mutant cells carrying another allele, dup(a3), undergo a partial S16 and delay the entry into M16. Thus, initiation of S16 appears necessary for delaying M16. This delay is absent in double mutants of dup(a3) and mei-41 (Drosophila ATR), indicating that a mei-41-dependent checkpoint acts to delay the entry into mitosis in response to incomplete DNA replication. dup(a3) and dup(a1) mutant cells that enter M16 become arrested in M16. We find that mitotic cyclins are stabilized and that a spindle checkpoint protein, Bub1, localizes onto chromosomes during mitotic arrest in dup mutants. These features suggest an arrest prior to metaphase-anaphase transition. dup(a3) bub1 double mutant cells exit M16, indicating that a bub1-mediated checkpoint acts to block mitotic exit in dup mutants. To our knowledge, this is the first report of (1) incomplete DNA replication affecting both the entry into and the exit from mitosis in a single cell cycle via different mechanisms and (2) the role of bub1 in regulating mitotic exit in response to incomplete DNA replication.

Alleles↗
PubMed2001

Meningoencephalitis in a Boelen's python (Morelia boeleni) associated with paramyxovirus infection.

An adult male Boelen's python, Morelia boeleni, presented with acute neurologic disease and was euthanatized. Histologic examination revealed nonsuppurative meningoencephalitis. Occasional eosinophilic intracytoplasmic inclusions were noted in glial cells. On the basis of clinical signs and histopathology, inclusion body disease of boid snakes was suspected, but inclusions were not seen in other organs commonly affected with the disease. Moreover, electron microscopy revealed that the inclusions contained stacks of filaments 13-14 nm wide. With the use of a generic paramyxovirus cDNA probe, sections of brain and esophageal ganglion demonstrated hybridization. The findings indicate that paramyxovirus was the likely cause of the encephalomyelitis in this python, and this virus should be included in the differential diagnosis of pythons exhibiting central nervous system disease.

Animals↗
PubMed2000

Youth injury data in the Canadian Hospitals Injury Reporting and Prevention Program: do they represent the Canadian experience?

OBJECTIVE: Injuries to Canadian youth (11-15 years) identified from a population based health survey (World Health Organization-Health Behaviour in School-Aged Children Survey, or WHO-HBSC) were compared with youth injuries from a national, emergency department based surveillance system. Comparisons focused on external causes of injury, and examined whether similar rankings of injury patterns and hence priorities for intervention were identified by the different systems. SETTING: The Canadian version of the WHO-HBSC was conducted in 1998. The Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) is the national, emergency room based, surveillance program. Two hospitals involved in CHIRPP collectively provide population based data for Kingston, Ontario. METHOD: Numbers of injuries selected for study varied by data source: WHO-HBSC (n=3673); CHIRPP (n=20,133); Kingston CHIRPP (n=1944). WHO-HBSC and Kingston CHIRPP records were coded according to four variables in the draft International Classification of External Causes of Injury. Existing CHIRPP codes were available to compare Kingston and other CHIRPP data by five variables. Males and females in the three datasets were ranked according to the external causes. Data classified by source and sex were compared using Spearman's rank correlation statistic. RESULTS: Rank orders of four variables describing external causes were remarkably similar between the WHO-HBSC and Kingston CHIRPP (p>0.78; p<0.004) for mechanism, object, location, and activity). The Kingston and other CHIRPP data were also similar (p>0.87; p<0.001) for the variables available to describe external causes of injury (including intent). CONCLUSION: The two subsets of the CHIRPP data and the WHO-HBSC data identified similar priorities for injury prevention among young people. These findings indicate that CHIRPP may be representative of general youth injury patterns in Canada. Our study provides a novel and practical model for the validation of injury surveillance programs.

Accident Prevention↗
PubMed2000

Proliferative osteoarthritis and osteoarthrosis in 15 snakes.

Fifteen snakes representing seven species with segmental, proliferative osteoarthritis and osteoarthrosis of the spine were presented for examination. All the snakes were captive, privately owned, and fed domestic rodents. Physical examination, radiography, blood culture, bone culture, necropsy, and histopathology were performed on each snake. All the snakes had similar physical examination, radiologic, and necropsy findings. There were three histologic types of lesions: active bacterial osteoarthritis, predominantly noninflammatory osteoarthrosis with multifocal inflammation suggestive of chronic bacterial osteoarthritis, and noninflammatory lesions consistent with osteoarthrosis without evidence of inflammation or bacteria. These findings suggest that all these snakes represent a single disease process, bacterial infection of the vertebrae. The different histologic lesions observed in these snakes may be a continuum of lesions, from acute to chronic. Gram-negative bacteria were isolated from the blood or bone lesions of 8 of the 15 snakes. In six of these eight snakes, Salmonella species were isolated. Gram-positive bacteria (Streptococcus sp.) were isolated from two other snakes. Blood and bone culture results were well correlated, so blood culture may be effective for detecting active bacterial osteoarthritis.

Animals↗
PubMed1999

A search for the evidence supporting community paediatric practice.

AIM: Controversy exists regarding the evidence base of medicine. Estimates range from 20% to 80% in various specialties, but there have been no studies in paediatrics. The aim of this study was to ascertain the evidence base for community paediatrics. METHODS: Twelve community paediatricians working in clinics and schools in Yorkshire, Manchester, Teesside, and Cheshire carried out a prospective review of consecutive clinical contacts. Evidence for diagnostic processes, prescribing, referrals, counselling/advice, and child health promotion was found by searching electronic databases. This information was critically appraised and a consensus was obtained regarding quality and whether it supported actions taken. RESULTS: Two hundred and forty-seven consultations and 1149 clinical actions were performed. Good evidence was found from a randomised controlled trial or other appropriate study for 39.9% of the 629 actions studied; convincing non-experimental evidence for 7%; inconclusive evidence for 25.4%; evidence of ineffectiveness for 0.2%; and no evidence for 27.5%. Prescribing and child health promotion activities had the highest levels of quality evidence, and counselling/advice had the lowest. CONCLUSIONS: An encouraging amount of evidence was found to support much of community paediatric practice. This study improved on previous research in other specialties because actions other than medications and surgery were included.

Child↗
PubMed1999

Exploring the scope for advocacy by paediatricians.

AIMS: To ascertain the type and extent of problems requiring advocacy in paediatrics. To develop an approach for analysing problems according to their root causes and the level of society at which advocacy is needed. METHODS: Nine paediatricians kept detailed clinical diaries for two weeks to identify problems. Classifications were developed to categorise problems by cause and the level of society at which they needed to be addressed. The press was surveyed for one week for childhood issues attracting media attention. RESULTS: 60 problems requiring advocacy were identified. Root causes included failures within agencies, between agencies, and inadequate provision. In addition to advocacy required individually, "political" action was needed at the community level (16 issues), city level (16 issues), and nationally (15 issues). 103 articles were found in the press, these did not relate closely to issues identified by clinicians. CONCLUSIONS: Many opportunities for advocacy arise in the course of daily work. A systematic way of analysing them has been developed for use in planning action. To optimise the health and health care of children, there is a need to train and support paediatricians in advocacy work for local as well as national issues. Ten issues were identified that might be prioritised by paediatricians working on an agenda for action.

Child↗
PubMed1997

Menadione-resistant Chinese hamster ovary cells have an increased capacity for glutathione synthesis.

A cell line (MRc40) resistant to the model quinone compound, menadione, has been isolated from a parental Chinese hamster ovary cell line (CHO-K1). The known relationship between menadione toxicity and glutathione (GSH) depletion led us to investigate whether the mechanism of resistance of MRc40 was related to alteration in GSH homeostasis. Intracellular concentrations of GSH and cysteine (CySH) were twofold and 3.2-fold greater in MRc40 than in CHO-K1. Following exposure to menadione, GSH and CySH were depleted, but subsequent recovery of thiols was more rapid and of greater magnitude in MRc40 than in CHO-K1. Twelve hours after exposure to menadione, the concentrations of GSH and CySH were 9.7- and 4.2-fold greater in MRc40 than in CHO-K1. Using nuclear magnetic resonance (NMR) spectroscopy, we observed the in situ removal of menadione from cell suspensions of CHO-K1 and MRc40. However, only in CHO-K1 did we observe concomitant depletion of NMR-visible GSH. We conclude that the perturbation of GSH metabolism contributes to the resistant phenotype and is an important characteristic of menadione-resistant CHO cells.

Animals↗
PubMed1997

Understanding surgery: multimedia comes to theatre.

Educational technology is well established within Schools of Nursing, however there are few computer based learning packages within the clinical environment. It was felt within the Operating Services Directorate, Royal Hallamshire Hospital, that the development of a multimedia package would enhance and complement existing teaching methods. This paper describes the theory behind the choice of a multimedia presentation and its development within the operating theatres. The package, concentrating on general surgery, has been developed by two experienced theatre nurses and a graphic designer. This has resulted in a structured but flexible, fun package which is relevant to all learners within the operating theatre environment and allied healthcare fields. The feedback obtained from users within the clinical area has reinforced the project team's original feeling that multimedia is a highly appropriate resource for clinical education.

Computer Graphics↗
PubMed1995

Injection bias of DNA fragments in capillary electrophoresis with sieving.

The relative amounts of DNA fragments in a mixture injected into the capillary by electromigration or hydrodynamically by pressure were compared. Even if the electrophoretic mobilities of DNA fragments with different sizes are the same in a free solution in the sample vial, the size bias is brought about by the different mobilities in a sieving medium and by the electroosmosis. The experiments were performed in capillaries filled with a solution of liquified agarose, a replaceable sieving medium. The experimental results were compared with a theoretical model.

Bacteriophage phi X 174↗
PubMed1995

A comparison of resolution of DNA fragments between agarose gel and capillary zone electrophoresis in agarose solutions.

The resolving power of capillary zone electrophoresis (CZE) is compared to that of gel electrophoresis (GE) under similar conditions (agarose, similar length of DNA fragments, identical buffer) but with differences in temperature and field strength. The comparison is based on the time required to reach a desired degree of resolution by each of the two methods. A resolution parameter is developed which is equally applicable to CZE, with relatively diffuse initial conditions in the absence of stacking and measurements expressed in terms of time, and to GE, in which measurements are expressed in terms of spatial parameters. The resolution time in CZE using agarose solutions at 40 degrees C was found to be greater by at least one order of magnitude than that in GE using agarose gels. Thus, the increased migration velocity due to high field strength in CZE substantially outweighs the lower dispersion in GE.

DNA↗
PubMed1995

Reducing relocation stress after discharge from the intensive therapy unit.

Moving from the intensive therapy unit (ITU) to the ward environment can be a very stressful experience for patients. Nursing interventions can help to reduce the stress associated with this experience and help each patient to cope with it. The factors which cause relocation stress are discussed along with a strategy employed clinically to reduce or prevent this problem in patients after discharge from an ITU.

Adaptation, Psychological↗
PubMed1995

Spinal meningeal sarcoma in a rottweiler puppy.

An 11-week-old rottweiler puppy was presented for evaluation of progressive paraparesis, urinary and faecal incontinence. Radiography and myelography revealed widening of the vertebral canal and remodelling of several lumbar vertebrae associated with an intramedullary spinal mass. Magnetic resonance imaging revealed an extensive, heterogeneous mass involving the lumbosacral spinal cord. Histopathological examination indicated a meningeal sarcoma with very varied cytological architecture.

Animals↗
PubMed1994

Are most transporters and channels beta barrels?

Given the sequence of transporters or channels of unknown secondary structure, it is usual to predict their putative transmembrane regions as alpha-helical. However, recent evidence for a facilitative glucose transporter (GLUT1) appears inconsistent with such predictions, which has led us to propose an alternative folding model for GLUTs based on the 16-stranded antiparallel beta-barrel of porins. Here we apply the same predictive algorithms we used for GLUTs to several other membrane proteins. For some of them, a high-resolution structure has been derived (beta-barrels: Rhodobacter capsulatus and Escherichia coli porins; multihelical: colicin A, bacteriorhodopsin, and reaction center L chain); we use them to test the prediction procedures. The other proteins we analyze (GLUT1, CHIP28, acetylcholine receptor alpha subunit, lac permease, Na(+)-glucose cotransporter, shaker K+ channel, sarcoplasmic reticulum Ca(2+)-ATPase) are representative of classes of similar membrane proteins. As with GLUTs, we find that the predicted transmembrane segments of these proteins are consistently shorter than expected for transmembrane spanning alpha-helices, but are of the correct length and number for the proteins to fold instead as porin-like beta-barrels.

Algorithms↗
PubMed1994

The interaction of colloidal metals with erythrocytes.

The interactions of citrate reduced colloids (Ag, Au, and Bi) with intact erythrocytes and erythrocyte lysate have been studied by 1H spin echo NMR. Silver colloid is observed to induce cellular depletion of cytosolic glutathione and bismuth colloid induces cytosolic glutathione oxidation in the intact cell. In comparison, there is no detectable effect with gold colloid. With red cell lysate the three colloids all remove glutathione from the spectrum. The metal salts AgNO3 and NaAuCl4 both oxidize intracellular glutathione to diglutathione whereas BiO(NO3) has no effect. Thus colloidal preparations have a different reactivity to their parent metal salts. The differences observed between the three types of colloids (silver, gold, and bismuth) are unique to the colloids studied. None of the colloids studied were biologically inert in the erythrocyte model used.

Bismuth↗
PubMed1993

Evidence that facilitative glucose transporters may fold as beta-barrels.

A widely accepted model for the structure of the facilitative glucose transporters (GLUTs) predicts that they form 12 transmembrane alpha-helices and that the highly conserved sequence Ile-386-Ala-405 in GLUT1 is intracellular. We raised a polyclonal antibody against a synthetic peptide encompassing this conserved sequence and found that antibody treatment increased 2-deoxy-D-glucose (DOG) uptake in Xe-nopus oocytes expressing GLUT1, GLUT2, or GLUT4 only when applied to the extracellular side. This effect was dose dependent and was specifically blocked by competition with the peptide Ile-386-Ala-405; it was due to a decrease in the Km for the transport of DOG. To ascertain GLUT orientation, we raised anti-peptide antibodies against the last 21 and 25 C-terminal amino acids of GLUT1 and GLUT4, respectively, which were previously shown to be intracellular. These antibodies increased DOG uptake when injected into oocytes expressing GLUT1 and GLUT4, but not when added extracellularly. Prompted by the noted discrepancy, we found sequence similarity between GLUTs and porins, two of which are known from crystallography to form 16-stranded transmembrane antiparallel beta-barrels. Analysis of the hydrophobicity, amphiphilicity, and turn propensity of GLUT1 leads us to propose that GLUTs fold as porin-like transmembrane beta-barrels. This model is consistent with the results of the present antibody studies and also with previously published experimental evidence inconsistent with the 12-helix model.

Amino Acid Sequence↗
PubMed1992

Capital PPS transition period affects timing differences.

The Health Care Financing Administration's new capital payment system means hospitals face timing differences in their financial statements. A hospital's 10-year transition into the new system could involve a switch from the hold-harmless payment method to the fully prospective method. To maximize the recoverability of deferred assets and liabilities, hospitals should understand the details of both methods and how changes in third-party payment programs can affect timing differences.

Accounting↗
PubMed1991

Suspected lead toxicosis in a captive goshawk.

Lead toxicosis was diagnosed in a 3-week-old male goshawk after evaluation of the history, clinical signs, radiographic lesions, and laboratory values. Treatment with Ca-EDTA and supportive measures was successful. The presumed source of lead was from birds that had been shot with a pellet gun and used for food.

Animals↗