PubMed Health⌕ Search

Biomedical subjects

N M Robinson

Publications and source records attributed to N M Robinson.

At least 19 recordsLinked to original sources
PubMed2000

Two tails of the normal curve. Similarities and differences in the study of mental retardation and giftedness.

Professionals in the fields of mental retardation and giftedness have much to teach each other as well as the field of human development in general. Examining the commonalities and differences between the fields in social issues, definitions, developmental differences from the norm, values and policy issues, and educational and long-term implications deepens insights about both normal and deviant development. The authors stress the importance of individual differences in the differential design of educational strategies and the application of approaches developed with specialized populations to normally developing children. Current social inequalities affect both of these fields in particular ways. Finally, numerous research agendas can be enhanced by including representatives of both ends of the normal curve.

Adolescent↗
PubMed2000

Transvenous pacing lead-induced thrombosis: a series of cases with a review of the literature.

Although transvenous pacing is a safe treatment modality for bradyarrhythmias, serious thrombotic and embolic complications are reported to occur in 0.6-3.5% of cases. We describe 5 cases of pacemaker-associated thrombosis, 3 with a superior vena cava syndrome (SVC), 1 with an axillary vein thrombosis and 1 with a thrombus attached to the pacing lead in the right atrium. All of the patients were initially treated with intravenous heparin which proved successful as the sole treatment in only the least severe case (axillary vein thrombosis). One of the patients with SVC obstruction was successfully treated with intravenous heparin followed by thrombolytic therapy. The remaining 3 cases (2 SVC syndromes and 1 right atrial thrombus) required surgical removal of thrombus and pacing leads. Both of the patients with evidence of infection were in the group for whom failure of medical therapy necessitated surgery.

Adult↗
PubMed1999

Angiographic and clinical restenosis following the use of long coronary Wallstents.

This study assessed clinical and angiographic restenosis following the deployment of the long coronary Wallstent. Between May 1995 and June 1997, 182 Wallstents were deployed in 162 vessels in this unit. Forty-eight percent had an unstable coronary syndrome and 94% had AHA grade B or C lesions. The mean lesion length was 37 +/- 20 mm and the mean stent length was 48 +/- 20 mm. The procedural success rate was 99% and the primary success rate was 93%. Six in-patients suffered subacute stent thrombosis, the majority being in the era of anticoagulation rather than antiplatelet regimes. Seventy-three percent remained free of major adverse clinical events in the follow-up period, but 41% had angiographic restenosis. The Wallstent can be deployed in complex lesions with a high primary success rate and an acceptably low restenosis rate. The optimal management of in-stent restenosis remains to be defined.

Adult↗
PubMed1999

Induction of myocardial nitric oxide synthase by Coxsackie B3 virus in mice.

BACKGROUND: Inducible nitric oxide synthase (iNOS) expression is regulated by cytokines. This study investigated whether Coxsackie group B virus (CVB) myocarditis resulted in an environment suitable for induction of NOS in the murine heart. MATERIALS AND METHODS: Myocardium was removed from mice infected with CVB3 and from controls. Histology, reverse transcriptase polymerase reaction (RT-PCR) for murine iNOS, NOS enzyme activity and immunohistochemistry were assessed. RESULTS: Histology revealed severe myocarditis 7 days after infection with CVB3 but not in controls. RT-PCR using primers for murine iNOS detected iNOS mRNA in infected mice but not in controls. Calcium-independent NOS activity increased by day 5 after infection with a peak at day 7. Calcium-dependent NOS activity was present throughout, with a trend to lower levels during peak calcium-independent activity. Immunohistochemistry revealed iNOS to be localized to inflammatory cells rather than to myocytes. CONCLUSION: This study demonstrates the development of calcium-independent NOS activity and de novo gene transcription for iNOS in the murine myocardium in response to CVB3 infection. The nitric oxide produced at such high output may act at times as part of the immune defence as an antiviral agent and may be toxic to host tissue.

Animals↗
PubMed1998

Characterization of Coxsackie B virus RNA in myocardium from patients with dilated cardiomyopathy by nucleotide sequencing of reverse transcription-nested polymerase chain reaction products.

This study was performed to detect and characterize the enterovirus present in myocardium of some patients with heart muscle disease by nucleotide sequencing of polymerase chain reaction (PCR) products after amplification with enterovirus group-specific primers. Enterovirus sequences have been detected previously in myocardium of patients with myocarditis or dilated cardiomyopathy and seem causal, although the particular virus serotypes involved have not been identified. In a prospective study of endomyocardial biopsy specimens from 35 consecutive patients with suspected heart muscle disease, enterovirus sequences from the 5' nontranslated region were amplified by reverse transcription-nested PCR using group-specific primers. This region contains both conserved and variable sequence motifs, characteristic of particular enterovirus serotypes. The nucleotide sequences of individual PCR products were determined by cycle sequencing and compared with all known sequences (GenBank/EMBOL), using the GCG software package. Endomyocardial biopsy specimens from 9 of 21 (42.9%) patients with a histologically confirmed diagnosis of dilated cardiomyopathy were positive for enterovirus by PCR, compared with only 1 of 14 (7.1%) patients with other myocardial pathological conditions (Fisher's exact probability=0.0275: odds ratio=9.75; 95% confidence interval=1.31-72.78). The nucleotide sequence of the PCR products differed, indicating no cross-contamination. However, computerized comparison showed that each had greatest homology with the 5' nontranslated region of Coxsackie B virus but contained up to 11% sequence variations compared with the prototype Coxsackie B3 strain Nancy. Parallel investigation of tissue from our mouse model of Coxsackievirus B3-induced myocarditis showed that nucleotide sequence changes are not introduced by reverse transcription or PCR. These data support the link between enteroviral infection and dilated heart muscle disease and suggest that Coxsackie B serotypes are the enteroviruses most frequently involved.

Adolescent↗
PubMed1997

Inducible nitric oxide synthase gene transcription and protein activity in the rat heart during endotoxaemia.

Septicaemia leads to an impairment of myocardial contractility in animals and humans. Cytokines released during endotoxaemia are capable of increasing inducible nitric oxide synthase (iNOS) expression in vitro in myocytes, endothelial cells and macrophages. The aim of this study was to assess whether iNOS gene transcription occurs in the myocyte in vivo. Rats were injected with intraperitoneal endotoxin. Myocardial sections obtained 4, 6 and 8 hours after infection were hybridised with oligonucleotides complementary to iNOS cDNA. Myocardial homogenates were used to measure NOS enzyme activity and to detect iNOS mRNA. Uninfected control animals did not demonstrate myocardial iNOS expression. Myocardium from endotoxaemic animals contained iNOS mRNA and high calcium-independent NOS enzyme activity. In situ hybridisation did not localise iNOS to myocytes but to cells located between myocytes. Endotoxaemia leads to iNOS gene transcription and calcium-independent NOS enzyme activity in the rat myocardium. In situ hybridisation demonstrates that iNOS is not transcribed by the myocyte in vivo.

Animals↗
PubMed1997

Induction and role of NO synthase in hypotensive hepatic failure.

Nitric oxide (NO) plays an important role in the physiological and pathophysiological control of the vascular system. NO is synthesized by isoforms of the enzyme NO synthase (NOS). Hepatic failure is complicated by hypotension, low systemic vascular resistance, and resistance to vasoconstrictor drugs. The potential role of NO in these abnormalities was investigated by using in vitro pharmacological interventions on hepatic arteries obtained from both donor and recipient patients at the time of liver transplantation. The presence of NOS mRNA was investigated by reverse transcription polymerase chain reaction (RT-PCR) with primers designed from human endothelial NOS (eNOS) and inducible NOS (iNOS) cDNA sequences. Arteries from patients with hepatic failure had an impaired constrictor response to phenylephrine compared with those of donor arteries. The constrictor effect of phenylephrine was potentiated by NG-monomethyl-L-arginine, an inhibitor of NOS, which had no effect in donor control arteries. RT-PCR identified human eNOS mRNA in donor and recipient arteries and human iNOS mRNA in recipient arteries only. Induction of NOS in the vasculature with subsequent NO-induced vasodilatation may therefore contribute to the hemodynamic abnormalities observed in hepatic failure and potentially in other pathologies associated with endotoxemia. Whether selective inhibitors of iNOS will improve hemodynamic control or clinical outcome in these conditions requires further study.

Acetylcholine↗
PubMed1996

Electrical injury to the heart may cause long-term damage to conducting tissue: a hypothesis and review of the literature.

Electrical injury, particularly alternating current, may lead to disease of conducting tissue, myocardial damage or may cause sudden cardiac death. Subtle abnormalities, particularly of sinus node function, may pose diagnostic difficulties and may not present for many years. The long-term follow-up of patients, perhaps as part of a registry, will help to define the clinical spectrum of cardiac presentations of electrical injury.

Death, Sudden, Cardiac↗
PubMed1995

Spontaneous haemothorax as a complication of anti-coagulation following coronary angioplasty.

Haemorrhagic complications are well recognized when heparin is used during percutaneous transluminal coronary angioplasty (PTCA). We present a 74-year-old female who developed a large acute spontaneous haemothorax 20 h after coronary angioplasty. Spontaneous haemothorax has rarely been described and is predominantly associated with pulmonary embolism. In the absence of a pulmonary embolus, a spontaneous haemothorax during anti-coagulation has only been described twice in the world literature since 1862 (1). This is the first description of this complication following the use of heparin during PTCA.

Aged↗
PubMed1994

Long-term developmental follow-up of infants of diabetic mothers.

The neurodevelopmental consequences of maternal insulin-dependent diabetes were studied in 109 infants of diabetic mothers and 90 control infants. The infants born to diabetic mothers included 70 "early entry" subjects and 39 "late entry" subjects. Maternal diabetes control during pregnancy was significantly better in "early entry" mothers than in late-entry mothers, as determined by glycosylated hemoglobin levels. Infants were examined by a psychologist and a developmental pediatrician unaware of group status at 6, 12, 24, and 36 months of age; 71% of the subjects completed the 3-year-study. Neurodevelopment of early-entry subjects was similar to that of control subjects, whereas late-entry subjects scored less well on language measures. Mean head size in late-entry subjects was significantly less (p = 0.03) than in either control subjects or early-entry subjects at age 3 years, and correlated negatively with glycosylated hemoglobin levels during all three trimesters. Less optimal intellectual development was associated with reduced head circumference. In addition, the presence of major congenital malformations was associated with reduced developmental performance through age 2 years. Our results indicate that mothers with insulin-dependent diabetes who maintain good control during pregnancy can expect to have infants who are neurodevelopmentally normal; mothers whose diabetes is less well controlled may have infants with less optimal neurodevelopment.

Child Development↗
PubMed1993

Combination drug testing of Mycobacterium chelonae.

PURPOSE: Medical therapy of Mycobacterium chelonae keratitis is difficult because there are so few effective antimicrobial agents and single agent therapy frequently fails clinically. To identify more effective medical treatment regimens, the in vitro antimicrobial efficacy of amikacin, the most frequently used single agent, was investigated in combination with four antibiotics previously reported to have activity against M. chelonae: erythromycin, imipenem, ciprofloxacin, and vancomycin. METHODS: The drug combinations were tested by the checkerboard method against seven corneal isolates of M. chelonae. RESULTS: The combination of amikacin with erythromycin or vancomycin consistently led to synergistic or additive effect, however the minimum inhibitory concentrations for vancomycin were very high. The combination of amikacin with imipenem or ciprofloxacin led to results ranging from antagonism to additive effects. CONCLUSIONS: Of the antibiotics tested, erythromycin showed the most activity against M. chelonae in combination with amikacin. In vitro combination drug testing of M. chelonae by the checkerboard method should be further evaluated for clinical relevance in microbial keratitis.

Amikacin↗