PubMed Health⌕ Search

Biomedical subjects

S McCullough

Publications and source records attributed to S McCullough.

18 recordsLinked to original sources
PubMed2006

Critical dependence of acetate thermal mattress on gel activation temperature.

BACKGROUND: Sodium acetate gel mattresses provide an active method of warming patients through release of latent heat of crystallisation. They can be used as an adjunct to incubator care or as an exclusive heat source. OBJECTIVE: To determine activation temperatures of the Transwarmer mattress needed to achieve plateau temperatures of 38-42 degrees C. DESIGN AND SETTING: In vitro testing of mattress temperature. METHODS AND OUTCOME MEASURES: Transwarmer mattresses were activated at initial temperatures ranging from 5 to 40 degrees C. Mattress temperature was recorded up to 4 h to determine peak and plateau temperatures. Peak and plateau temperatures achieved by the mattress were related to the initial starting temperature. RESULTS: The starting temperature of the mattress was strongly correlated with peak and plateau temperature (r = 0.99, p<0.001). To achieve the target temperature of 38-42 degrees C, the Transwarmer mattress requires activation between 19.2 degrees C and 28.3 degrees C. A temperature of 37 degrees C could be generated by activation at 17 degrees C. CONCLUSIONS: Safe use of this device is critically dependent on gel temperature at the point of activation. To ensure warming of a hypothermic neonatal patient without running any risk of burns, the mattress should be activated with a gel temperature between 19 degrees C and 28 degrees C.

Beds↗
PubMed2006

Epidemiology of bovine brucellosis in Northern Ireland between 1990 and 2000.

Between 1990 and 2000, 317 herds of cattle in Northern Ireland were identified as being seropositive to Brucella abortus, and 68 per cent of them were attributed to transmission from neighbouring herds or to local spread. Of particular significance were three primary outbreaks in 1997, which resulted in significant secondary and tertiary spread. Three spatial clusters were identified, corresponding to two of the primary outbreaks, and the herd density and within-herd spread were highest in the largest cluster. Abortions in an infected herd and the disease-risk status of the disclosure test were positively associated with an increased within-herd prevalence.

Animals↗
PubMed2006

Endotracheal tube position in neonates requiring emergency interhospital transfer.

A malpositioned endotracheal tube (ETT) is common following initial intubation. This study assessed ETT position in 53 orotracheally intubated neonates referred for interhospital transfer during a 3-month period. Position of the ETT on first chest radiograph (CXR) after intubation was assessed and related to radiographic lung expansion, with documentation that the final ETT length had achieved a satisfactory position. At the time of first CXR, median ETT length at the lips was 7.0 cm (range, 5 to 12 cm) with median tip position at T3.0 (range, C7 to T6). The ETT required repositioning in 58% of patients. Most malpositioned tubes were too low (26 were withdrawn and only four were advanced; p < 0.001), with lung expansion more closely related to vertebral than clavicular position of the ETT. Final ETT length correlated well with corrected gestation ( r = 0.83; p < 0.01) and marginally less well with weight ( r = 0.79; p < 0.01). From the regression analysis, we provide a table of recommended tube lengths by gestation.

Airway Obstruction↗
PubMed2005

Effects of vasectomy on spermatogenesis and fertility outcome after testicular sperm extraction combined with ICSI.

BACKGROUND: Each year 40,000 men have a vasectomy in the UK whilst another 2400 request a reversal to begin a second family. Sperm can now be obtained by testicular biopsy and subsequently used in assisted conception with ICSI. The study aims were to compare sperm yields of men post-vasectomy or with obstructive azoospermia (OA) of unknown aetiology with yields of fertile men and to assess any alteration in the clinical pregnancy rates after ICSI. METHODS: Testicular tissue was obtained by Trucut needle from men who had undergone a vasectomy >5 years previously or had OA from other causes and from fertile men during vasectomy. Seminiferous tubules were milked to measure sperm yields. Numbers of Sertoli cells and spermatids and thickness of the seminiferous tubule walls were assessed using quantitative computerized analysis. RESULTS AND CONCLUSIONS: Sperm yields/g testis were significantly decreased in men post-vasectomy and in men with OA, relative to fertile men. Significant reductions were also observed in early (40%) and mature (29%) spermatid numbers and an increase of 31% was seen in the seminiferous tubule wall (basal membrane and collagen thickness) of vasectomized men compared with fertile men. Clinical pregnancy rates in couples who had had a vasectomy were also significantly reduced.

Adult↗
PubMed2000

Sensitivity of FISH in detection of MLL translocations.

Fluorescence in situ hybridisation (FISH) detection of MLL translocations is now commonplace in cytogenetics laboratories. One of the most widely used probes is the Oncor MLL probe (Oncor, Gaithersburg, MD) that theoretically demonstrates the presence of an MLL rearrangement by a splitting of the FISH signal between the two derivative chromosomes generated by a translocation. Recently, another commercial probe has been made available from Vysis (Vysis, Downers Grove, IL) that uses a dual colour system. We examined material from 29 patients and 4 cell lines, all with recognised MLL translocations by G-banding, that were confirmed using Southern blot analysis of the MLL breakpoint cluster region. Both Oncor and Vysis MLL FISH probes were applied to these cases to compare their performance in detection of the MLL translocations. Thirty of the 33 cases demonstrated a clear splitting of Oncor MLL FISH signal in concordance with the Southern blot analysis and cytogenetics. Three cases failed to demonstrate a split MLL FISH signal. Therefore, we conclude that the Oncor MLL FISH probe has a 9.1% false negative rate, i.e., 90.9% sensitivity in detection of classic MLL translocations. Vysis MLL FISH detected the rearrangement in all 33 cases.

Blotting, Southern↗
PubMed2000

MLL amplification in acute leukaemia: a United Kingdom Cancer Cytogenetics Group (UKCCG) study.

The MLL gene, located at 11q23, is frequently rearranged in acute leukaemia as either chimaeric fusion genes or partial tandem duplications. We report a series of 12 acute leukaemia cases with apparent amplification of the MLL gene ascertained using fluorescence in situ hybridisation (FISH). Seven cases showed intrachromosomal amplification of MLL, four cases showed extrachromosomal amplification as double minute chromosomes (dmin) and one case had separate subclones with dmin and homogenously staining region (hsr). Southern blot analysis of the MLL gene showed MLL gene rearrangement in three of the 10 successful cases. These cases do not naturally fall into either of the two recognised categories of MLL rearrangement and may represent a third variety of MLL gene abnormalities.

Acute Disease↗
PubMed1999

Jumping translocation at 11q23 with MLL gene rearrangement and interstitial telomeric sequences.

myeloid leukemia of acute myeloid leukemia (AML) M5a showing a jumping translocation with a breakpoint at 11q23. Fluorescence in situ hybridization (FISH) demonstrated triplication of the MLL gene and the presence of interstitial telomeric sequences, supporting the role of repetitive sequences in the mechanism of jumping translocations. Southern blot analysis of the MLL breakpoint cluster region showed the presence of an MLL gene rearrangement. Jumping translocation with MLL gene rearrangement is a previously unreported phenomenon in leukemia cytogenetics.

Aged↗
PubMed1999

Collection and interpretation of respiratory cytology.

Advances in pulmonary cytological sampling have helped establish a more accurate diagnosis and better therapeutic choices for the respiratory patient. Choosing the appropriate test is necessary to maximize the potential diagnostic yield and should be based on the clinical presentation of the patient as well as the minimum database. This article describes several methods of collection of cytological samples for the canine and feline upper and lower respiratory tracts, defines normal respiratory cytology, and discusses normal cytological characterization of various respiratory diseases. Categorization of cytological findings may aid the clinician in narrowing the potential etiologies for the pulmonary disorder. The authors focus on cytological recovery and analysis from transtracheal wash (TTW), bronchial brushing, transthoracic lung aspiration (TTLA), bronchoalveolar lavage (BAL), and open chest biopsy. Indications, complications, and contraindications for each procedure are discussed. Variation in expected findings among BAL, TTW, TTLA, and bronchial brushings are described. Appropriate sampling technique, transport, and processing are also emphasized.

Animals↗
PubMed1997

Face processing by deaf ASL signers: evidence for expertise in distinguished local features.

Several previous studies have shown that ASL signers are 'experts' on at least one test of face processing: the Benton Test of Face Recognition, a discrimination task that requires subjects to select a target face from a set of faces shown in profile and/or in shadow. The experiments reported here were designed to discover why ASL signers have superior skill as measured by this test and to investigate whether enhanced performance extends to other aspects of face processing. Experiment 1 indicated that the enhancement in face-processing skills does not extend to recognition of faces from memory. Experiment 2 revealed that deaf and hearing subjects do not differ in their gestalt face-processing ability; they perform similarly on a closure test of face perception. Finally, experiment 3 suggested that ASL signers do exhibit a superior ability to detect subtle differences in facial features. This superior performance may be linked both to experience discriminating ASL grammatical facial expression and to experience with lipreading. We conclude that only specific aspects of face processing are enhanced in deaf signers: those skills relevant to detecting local feature configurations that must be generalized over individual faces.

Journal Article↗
PubMed1997

Enhanced facial discrimination: effects of experience with American sign language.

On-line comprehension of American Sign Language (ASL) requires rapid discrimination of linguistic facial expressions. We hypothesized that ASL signers' experience discriminating linguistic facial expressions might lead to enhanced performance for discriminating among different faces. Five experiments are reported that investigate signers' and non-signers' ability to discriminate human faces photographed under different conditions of orientation and lighting (the Benton Test of Facial Recognition). The results showed that deaf signers performed significantly better than hearing non-signers. Hearing native signers (born to deaf parents) also performed better than hearing nonsigners, suggesting that the enhanced performance of deaf signers is linked to experience with ASL rather than to auditory deprivation. Deaf signers who acquired ASL in early adulthood did not differ from native signers, which suggests that there is no 'critical period' during which signers must be exposed to ASL in order to exhibit enhanced face discrimination abilities. When the faces were inverted, signing and nonsigning groups did not differ in performance. This pattern of results suggests that experience with sign language affects mechanisms specific to face processing and does not produce a general enhancement of visual discrimination. Finally, a similar pattern of results was found with signing and nonsigning children, 6-9 years old. Overall, the results suggest that the brain mechanisms responsible for face processing are somewhat plastic and can be affected by experience. We discuss implications of these results for the relation between language and cognition.

Journal Article↗
PubMed1996

Diagnostic tests for Helicobacter pylori--can they help select patients for endoscopy?

AIM: Dyspepsia is a common symptom and some selection process for endoscopy is required. This study seeks to determine if noninvasive tests for Helicobacter pylori could be useful as a screening test to help select patients for endoscopy. METHODS: Consecutive patients attending for upper gastrointestinal endoscopy were interviewed prior to endoscopy and the endoscopic diagnoses was recorded. The presence of Helicobacter pylori infection was assessed by serology. Some patients also had a 13C urea breath test or rapid urease test (CLO test). RESULTS: 436 consecutive patients were evaluated. The endoscopy findings were normal in 44%, 29% had reflux oesophagitis, 18% had duodenal ulcer, duodenitis or gastric ulcer and 9% had other diagnoses. 54.8% of patients were positive for Helicobacter serology. Using either the CLO test or 13C urea breath test as the confirmatory test for the diagnosis of Helicobacter pylori, the sensitivity of the serology test was 96% and 91% respectively and the specificity was 66.6 and 82%. Patients with negative serology and no history of recent NSAID or aspirin use comprised 34% of the total with dyspepsia or reflux symptoms. There were no gastric or duodenal ulcers in this group. CONCLUSION: The serology test may have some potential or the initial evaluation of dyspepsia. These tests need to be prospectively evaluated in general practice.

Adolescent↗
PubMed1996

Prevalence of Helicobacter pylori infection in different ethnic groups in New Zealand children and adults.

BACKGROUND: Helicobacter pylori infection is a major risk factor for peptic ulcer disease and gastric cancer. A study of patients with dyspepsia attending for gastroscopy showed significant differences in H. pylori seropositivity between ethnic groups. AIMS: To determine the prevalence of H. pylori in children and adults in the community in different ethnic groups and to identify risk factors for infection. METHODS: Serum samples (324) were randomly selected from a cross-sectional survey of 11-12 year old school children with a high proportion of Maori and Pacific Island groups. Serum samples (579) were randomly selected from a cross-sectional workforce survey of 5677 participants aged 40-64 years. Serum samples were tested for H.pylori IgG. RESULTS: The percentage seropositivity in 11-12 year old children was European 7%, Maori/part Maori 21%, all Pacific Island groups 48% and for the workforce survey 35.8%, 57.4% and 73.2% respectively. Compared with Europeans the increased relative risk of seropositivity for H.pylori in Maori and Pacific Island participants was significant after adjusting for age and socio-economic status (1.43 [1.13, 1.80] and 1.76 [1.43, 2.18]) respectively. The relative risk of H.pylori infection significantly increased with age, lower socio-economic status and lower household income, but was not significantly associated with gender, alcohol or cigarette use. CONCLUSIONS: The high seroprevalence of H.pylori in Maori and Pacific Island groups is consistent with the differences in incidence of gastric cancer. H.pylori continues to be a common infection in Maori and Pacific Island school children. Ethnicity appears to be a risk factor for H.pylori independent of socio-economic status.

Adult↗
PubMed1993

Diagnostic imagings for primary cardiac fibrosarcoma.

Primary tumors of the heart are rare; primary cardiac fibrosarcoma is even rarer. We report a patient with primary cardiac fibrosarcoma widespread metastases presenting with pulmonary metastases initially. The cardiac lesion was identified by bone-imaging localization on bone scan, by hypodense areas in the cardiac chambers of contrast computed tomography of the chest, and by protruding masses in ventricular cavities causing aortic valve outflow-tract obstruction by echocardiogram. At autopsy, a large tumor invaded the interventricular septum and both ventricular cavities of the heart (880 g in weight), and accounted for these imaging findings. While bone-agent localization in the heart does not differentiate malignant from benign conditions, computed tomography and echocardiography of the interatrial and interventricular septal, and right atrial and biventricular cavitary involvement may differentiate fibrosarcoma from myxoma.

Aged↗
PubMed1992

Isolation of swine infertility and respiratory syndrome virus (isolate ATCC VR-2332) in North America and experimental reproduction of the disease in gnotobiotic pigs.

A recent epizootic of swine infertility and respiratory syndrome (SIRS) in a Minnesota swine herd was investigated. Examination of a sow, neonatal piglets, and stillborn fetuses obtained during the epizootic from the affected herd revealed interstitial pneumonitis, lymphomononuclear encephalitis, and lymphomononuclear myocarditis in the piglets and focal vasculitis in the brain of the sow. Fetuses did not have microscopic lesions. No cause for the infertility and respiratory syndrome was determined. Therefore, attempts were made to experimentally reproduce the disease. Eleven 3-day-old gnotobiotic piglets exposed intranasally to tissue homogenates of piglets from the epizootic became inappetent and febrile by 2-4 days postexposure and had interstitial pneumonitis and encephalitis similar to that seen in the field outbreak. After 2 blind passages in gnotobiotic piglets, tissue homogenates were cultured on continuous cell line CL2621, and a cytopathic virus (ATCC VR-2332), provisionally named SIRS virus, was isolated. Gnotobiotic piglets exposed intranasally to the SIRS virus developed clinical signs and microscopic lesions that were the same as those in piglets exposed to the tissue homogenates, and the virus was reisolated from their lungs. This is the first isolate of SIRS virus in the United States that fulfills Koch's postulates in producing the respiratory form of the disease in gnotobiotic piglets and the first report of isolation and propagation of the virus on a continuous cell line (CL2621). The virus is designated as American Type Culture Collection VR-2332.

Animals↗
PubMed1986

Catecholamine content of the preovulatory follicles of the domestic hen.

The role of catecholamines in ovarian function of the domestic hen has not been examined extensively. The aim of this study was first to determine the location of catecholamines in the preovulatory follicle of the domestic hen. Second, norepinephrine (NE), epinephrine (EPI) and dopamine (DA) were measured in the isolated theca layer of the five largest preovulatory follicles at specific times during the ovulatory cycle and changes in catecholamine content were correlated with ovarian events. The five largest preovulatory follicles were removed from chickens at 24, 18, 12, 6 and 2 h before ovulation of the largest (F1) follicle. Theca and granulosa layers were isolated, frozen, weighed and prepared for measurements of catecholamines by the double isotope radio-enzymatic assay. Catecholamines were localized primarily in the theca layer with only small amounts present in the granulosa layer. Norepinephrine was present in the theca layer in concentrations 6- and 30-fold those of EPI and DA, respectively. The content of NE and EPI in the theca layer of the F1 follicle was significantly (p less than 0.01) higher at 6 h before ovulation than at other times for the F1 follicle. In contrast, NE and EPI content of the theca layer of second (F2) and third (F3) largest follicles did not change during the ovulatory cycle. The content of DA was elevated (p less than 0.05) at 12 h before ovulation in F1 and F2 follicles. There was a significant reduction in NE in the theca layer of the fifth largest (F5) follicle between 24 and 18 h before ovulation of the F1 follicle.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗