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Biomedical subjects

M B Taylor

Publications and source records attributed to M B Taylor.

At least 37 records · Page 2Linked to original sources
PubMed2000

Dynamic susceptibility contrast enhanced MRI in reversible posterior leukoencephalopathy syndrome associated with haemolytic uraemic syndrome.

We describe a case of reversible posterior leukoencephalopathy associated with haemolytic uraemic syndrome. Following remission confirmed on MRI, the patient relapsed several months later. Neuroimaging findings on conventional MRI and FLAIR sequences and dynamic susceptibility contrast enhanced MRI are described. White matter abnormalities may be shown on CT or MRI in this syndrome. However, dynamic susceptibility contrast enhanced MRI showed far more extensive abnormality within the brain. In addition, phase contrast angiographic measurement of flow in the carotid and basilar arteries indicated a significant elevation of cerebral blood flow, suggesting a decrease in global cerebrovascular resistance. These observations support existing theories that the disorder is manifested by autoregulatory disturbance in small cerebral vessels. Our findings suggest that this abnormality is far more extensive than is demonstrated on T2 weighted MR images and that it is associated with global abnormality of cerebrovascular autoregulation.

Adult↗
PubMed1999

Low incidence of significant valvar insufficiency following retrograde aortic radiofrequency catheter ablation in young patients.

The incidence of significant valvar insufficiency at late (<6 month) follow-up was retrospectively evaluated in 27 young patients (age 4. 0-18.0 years) undergoing 29 ablation procedures via the retrograde aortic approach for left-sided accessory connections in whom pre-ablation and post-ablation echocardiograms were available for review. Valvar insufficiency was graded using color flow techniques as absent, trivial, mild, moderate, or severe by blinded reviewers. Ablation was acutely successful via the retrograde approach in 25 of 29 procedures among these 27 patients. Successful ablation was ultimately achieved in all 27 patients. At baseline, 7 patients had evidence of trivial or mild mitral insufficiency, and no patient had aortic insufficiency. Three patients had evidence of impaired left ventricular systolic performance in the presence of manifest pre-excitation. At follow-up, pre-existing mitral insufficiency resolved in 5/7 patients, and persisted in 2 patients. New mitral insufficiency was evident in 3 patients, and new aortic insufficiency was transiently evident in 1 patient following ablation (all trivial). Institutional experience (mean rank 10 cases vs. 33 cases, p <.0005), and lower patient weight (29.7 vs. 56.3 kilograms, p =.01) were the only factors associated with the development of new valvar insufficiency. Valvar insufficiency could not be detected by careful auscultation in any patient and was deemed clinically insignificant in all patients. We conclude that ablation of left-sided accessory connections can be performed via the retrograde aortic approach without creating clinically significant valvar insufficiency.

Adolescent↗
PubMed1999

Comparative studies of human rotavirus serotype G8 strains recovered in South Africa and the United Kingdom.

Epidemiological studies on the VP7 serotype prevalence of human rotaviruses in South Africa and the United Kingdom identified several strains which could not be serotyped as G1-G4 by monoclonal antibodies. Further analysis of these strains with a G8-specific monoclonal antibody and with probes for human rotaviruses confirmed them as G8 rotaviruses. These G8 strains exhibited a high degree of sequence identity when compared with each other and with other rotavirus G8 strains. Five South African strains were further characterized as VP6 subgroup I, but with a long RNA electropherotype, which is similar to the G8 strains previously isolated in Finland. In the UK strains, one was VP6 subgroup II with a long RNA electropherotype (similar to the Italian G8 strain). The other two were subgroup I with a short RNA electropherotype. None of these strains exhibited the super-short RNA electropherotype described in the prototype G8 strains recovered from Indonesia (69M).

Amino Acid Sequence↗
PubMed1997

Molecular epidemiology of South African strains of hepatitis A virus: 1982-1996.

Isolates of hepatitis A virus (HAV) are of a single serotype, with human isolates being categorised within four genotypes. In addition, there are three genotypes exclusively associated with Old World monkeys. In some geographical regions, related isolates cluster suggesting endemic spread of the virus, while in other regions several genotypes circulate. Virtually no data are available with regard to the genetic relatedness of South African (SA) strains of HAV. A 177 base segment within the VP1 region and a 168 base segment encompassing the putative VP1/P2A junction of 20 clinical and one environmental wild-type isolate(s) of HAV from SA were amplified by reverse transcriptase-polymerase chain reaction. The nucleotide sequences from the SA isolates showed > 85% nucleic acid sequence identity with published sequences for HAV strains from genotype I, with the majority of strains (81%) clustering within subgenotype IB and the remainder in subgenotype IA. A high degree of conservation was noted between the predicted amino acid sequences from SA clinical isolates and isolates from the rest of the world. Data presented indicate that in SA there is a circulating population of endemic HAVs from two distinct subgenotypes. This study provides valuable new data on the genetic relatedness of HAVs from southern Africa and the distribution of subgenotype IB.

Amino Acid Sequence↗
PubMed1997

Incidence of human calicivirus and rotavirus infection in patients with gastroenteritis in South Africa.

Human caliciviruses (HuCVs) are reportedly responsible for 2.5-4% of nonbacterial sporadic gastroenteritis. The incidence of HuCV infection in South Africa is unknown. Stool specimens from 1,296 South African patients with sporadic gastroenteritis were screened for the presence of HuCVs using electron microscopy, recombinant enzyme immunoassays for Norwalk (NV) and Mexican (MX) viruses, and the reverse transcriptase-polymerase chain reaction (RT-PCR). RT-PCR products were sequenced to ascertain which HuCV genogroups were present. HuCVs were detected in 43/1,296 (3.3%) specimens examined, with RT-PCR proving to be the most sensitive detection method. Genetic analysis of the isolates indicated that 81% were Snow Mountain Agent, or MX-like; 8% were NV-like; and 11% were HuCV/Sapporo-like. This study indicates that a combination of assays is needed for the accurate detection of HuCVs. Comparative data on hospitalised patients showed that the incidence of rotavirus infection was approximately ten times greater than that of HuCV infection.

Adolescent↗
PubMed1997

Propagation of human astrovirus in the PLC/PRF/5 hepatoma cell line.

Astroviruses are associated with gastroenteritis in humans and many diseases in animals. Human astroviruses (HAstVs) cannot be propagated readily or isolated in conventional cell cultures. The presence of trypsin supports HAstV growth in selected cell cultures such as the continuous colonic carcinoma cell line (CaCo-2). This study reports on the propagation of cell culture adapted reference strains of HAstV, and the direct isolation of HAstV from stool specimens in the human hepatoma cell line PLC/PRF/5.

Antigens, Viral↗
PubMed1997

Antiviral activity of galangin isolated from the aerial parts of Helichrysum aureonitens.

The in vitro antiviral activity of galangin (3,5,7-trihydroxyflavone), the major antimicrobial compound isolated from the shoots of Helichrysum aureonitens, was investigated against herpes simplex virus type 1 (HSV-1), coxsackie B virus type 1 (Cox B1), adenovirus type 31 (Ad31) and reovirus. At concentrations ranging from 12-47 micrograms/ml galangin showed significant antiviral activity against HSV-1 and CoxB1, limited activity against reovirus, and no antiviral activity against Ad31.

Adenoviruses, Human↗
PubMed1997

Rotavirus, astrovirus and adenovirus associated with an outbreak of gastroenteritis in a South African child care centre.

An outbreak of gastroenteritis in the infant-toddler unit of a child care centre (CCC) in Pretoria, South Africa, was investigated for possible viral enteropathogens. Rotavirus was found in association with seven (70%) diarrhoeal episodes. Co-infection with rotavirus and human astrovirus (HAstV) was demonstrated in two of these episodes, and rotavirus, HAstV and enteric adenovirus (EAd) co-infection in another. Rotavirus occurred alone in four of the diarrhoeal episodes, while HAstV and EAd were each detected alone in one episode. Two HAstV and one rotavirus asymptomatic infection episodes also occurred. Overall, 8 of 10 children had rotavirus infections, of which 7 were symptomatic, 6 of 10 children had HAstV infections (4 symptomatic), and 2 of 10 children had EAd infection, both symptomatic. These results highlight the diversity of viral enteropathogens that may be associated with a diarrhoeal outbreak in a CCC and emphasize the need to investigate the possibility that multiple enteropathogens may simultaneously cause a single outbreak of diarrhoea.

Adenoviridae Infections↗
PubMed1997

A minimally obtrusive, secure mask for prevention of access to the mouth.

Several childhood neurological conditions can lead to problems with unintended access to the mouth. Earlier workers have demonstrated benefits in the use of a helmet restricting mouth access, within a behavioural modification programme. Conventionally, such headgear is very obtrusive. This paper presents a simple technique using conventional plaster-based moulding, which has been successfully used in making secure, minimally obtrusive masks. Masks produced for two children have been readily accepted and have been successful. Any such headgear should be used only within a managed behavioural modification programme.

Adolescent↗
PubMed1997

Compassion: its neglect and importance.

Dose it matter that personal care of one doctor to one patient is being diluted by larger teams with increased delegation of work? In arguing that it does, this paper focuses on compassion, 'fellow feeling which is likely to be expressed'. General practitioner morale, patient satisfaction, and clinical medicine are examined, and teleology, game theory, and 'psycho-immuno endocrinology' touched upon, to come to the paper's conclusion, which is to call for the resuscitation of the 'Personal Doctor'.

Continuity of Patient Care↗
PubMed1997

Single-handed GPs.

Explore the source record for details and available documents.

Family Practice↗
PubMed1996

Inhibition of herpes simplex virus type 1 by aqueous extracts from shoots of Helichrysum aureonitens (Asteraceae).

Helichrysum aureonitens, a southern African medicinal plant reported to have antibacterial properties, was evaluated for antiviral activity against herpes simplex virus type 1 (HSV-1) in vitro. The crude aqueous extract from shoots of H. aureonitens at a concentration of 1.35 mg/ml (w/v) showed significant antiviral activity on HSV-1 in human lung fibroblasts as demonstrated by the absence of a cytopathic effect.

Antiviral Agents↗
PubMed1996

Seroepidemiology of HTLV-I in relation to that of HIV-1 in the Gauteng region, South Africa, using dried blood spots on filter papers.

The seroprevalence of human T-lymphotropic virus type I (HTLV-I), in relation to that of human immunodeficiency virus type I (HIV-1), was determined in a comparative unlinked anonymous antenatal and neonatal (for indirect measurement of maternal antibodies) serosurvey in the Gauteng region of South Africa, using dried blood spots (DBS) and modified particle agglutination assays. Samples were confirmed to be antibody positive by western blot. A total of 2582 DBS collected during 1993 and 1994 from subjects of African, European and coloured origin were tested. Ten were confirmed as positive for HTLV-I and 128 for HIV-1. No antibodies to HTLV-I or HIV-1 were demonstrated in the 221 women of European and coloured origin who were screened. The HTLV-I seroprevalence rate in subjects of African origin appeared to increase from 0% in 1993 to 0.49% in 1994, while HIV-1 seroprevalence rates of 5.2% and 5.4% were recorded for 1993 and 1994 respectively. No significant differences in HTLV-I and HIV-1 seroprevalence rates were noted for the two areas investigated. These results indicate that HTLV-I should be included in infection control programs, and provide baseline data for monitoring the possible spread of HTLV-I in the heterosexual population in this region.

Black People↗
PubMed1996

An epidemiological investigation of Norwalk virus infection in South Africa.

A study was carried out to determine the incidence and seroprevalence of Norwalk virus (NV) in the Pretoria area, South Africa, using a recombinant NV (rNV) immunoassay for the detection of serum IgG antibodies. Maternal antibody was detectable in infants' sera up to approximately 6 months of age. Infection with NV was detected serologically in the second year of life and the seroprevalence of NV IgG rose from 37.1% at 7-11 months of age to 62.1% by the age of 40 years. No significant differences in seroprevalence of NV IgG antibody was evident between subjects of European or African ethnic origin, where overall seroprevalence rates were 56.4% and 53.9% respectively.

Adolescent↗
PubMed1996

Assessment of commercial enzyme immunoassay for hepatitis C virus serotyping.

AIMS: To assess a commercial enzyme immunoassay (EIA) for the serotyping of hepatitis C virus (HCV) for routine use in a diagnostic laboratory setting, as well as for noting the serotype prevalence of selected specimens. METHODS: Seventy six serum specimens, submitted to the laboratory for routine hepatitis studies between May 1992 and February 1996 and stored at -20 degrees C, were evaluated. These specimens were categorised into specific hepatic, renal, and paediatric clinical conditions. The specimens all tested positive for HCV antibodies on a screening EIA, with confirmation on a recombinant immunoblot assay (RIBA). Certain specimens were also HCV RNA positive by the reverse transcription polymerase chain reaction (RT-PCR). All the specimens were serotyped using the newly developed serotyping EIA. RESULTS: Twenty seven (35.5%) specimens were typable. Type 5 predominated (56%), followed by type 1 (33%), types 1 and 6 (7%) and type 3 (4%). The serotype 5 specimens showed 85% and 90% reactivity with recombinant antigens c100-3 and c22-3c, respectively; serotype 1 specimens showed 75% and 100% reactivity with these antigens. All serotype 5 specimens reacted with the c33-c antigen, but only 60% of serotype 1 specimens reacted with this antigen. The differences in the reactivity of the serotype 5 and serotype 1 specimens for c33-c antigen in the RIBA were significant, but no significant differences in reactivity for antigens c-1-1, c100-3, and c22-3 were noted. Serotype 3 specimens showed equal reactivity with all four antigens used in the RIBA. CONCLUSION: The serotyping EIA was easy to use, rapid, and cost effective compared with molecular assays. This assay seems to be ideal for the routine diagnostic laboratory setting, but could not be used for certain clinical specimens. The demonstration of serotypes 5, 1, and 3 was not unexpected in this cohort. The occurrence of serotype 6, although concurrent and more likely to be a false cross reaction with serotype 1 peptides, requires confirmation by molecular genotyping before it can be claimed that this type is present in South Africa.

Adolescent↗
PubMed1996

A comparison of energy expenditure by a high level trans-femoral amputee using the Intelligent Prosthesis and conventionally damped prosthetic limbs.

Comparisons were made between the Intelligent Prosthesis (IP), Mauch and pneumatic swing phase control damping systems on the same prosthesis worn by a high level trans-femoral amputee. Speeds self selected by corridor walking (4.4-5.5 kmh-1) proved not to be sustainable for treadmill walking. Comfortable speeds were attained when the subject walked on a treadmill at 2.0, 2.6 and 3.2 kmh-1 in two tests for each prosthesis type. Oxygen uptake (VO2), cadence and heart rate were measured over 5 minute walks interspersed with rest periods. Spearman's correlation was used to test for differences between prosthesis types at each speed. At the two slower speeds no significant difference was found, but at the higher speed of 3.2 kmh-1, the IP was associated with a significantly lower VO2 (p < 0.05). A two way analysis of variance with replication (ANOVA) demonstrated a significant difference between VO2 for different limb types (p = 0.015). A square law function was fitted to the mean VO2 for each prosthesis type by the method of least squares regression. ANOVA demonstrated a significant difference between velocity coefficients for the different prosthesis types (p < 0.05). Cadence was almost constant during the period of each walk, varying by 1 step min-1 at most. However the test-retest differences in cadence were considerable. It is concluded that there was little difference in energy expenditure between prosthesis types at slower speeds, but at higher speeds (==> 3.2km h-1) the IP gave a lower oxygen uptake by about 10%.

Adult↗