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Biomedical subjects

A Ley

Publications and source records attributed to A Ley.

At least 19 recordsLinked to original sources

Use of 201Tl SPECT imaging to assess the response to therapy in patients with high grade gliomas.

PURPOSE: To assess the potential role of 201Tl single photon emission tomography (201-Thallium SPECT) when compared to other imaging modalities in the evaluation of the response to therapy in high grade gliomas. MATERIALS AND METHODS: Twenty patients with histologically proved high grade glioma have been included: 15 with glioblastoma (GBM), 3 with anaplastic astrocytoma (AA) and 2 with anaplastic oligoastrocytoma (AOA). Patients were assessed by 201Tl SPECT, computed tomography (CT) and magnetic resonance imaging (MRI) at (a) either at the moment of maximum response to first line chemotherapy, or after the completion of radiotherapy and chemotherapy if post-surgical residual disease was present, and (b) after the completion of second line chemotherapy if disease persisted, or either a relapse or disease progression was confirmed. Final response was evaluated according to the McDonald criteria, and by comparing SPECT, CT and MRI results. RESULTS: According to the McDonald criteria, clinical response after first line chemotherapy was 5 partial response, 7 stable disease and 8 progressive disease. Evaluation by 201Tl SPECT was in agreement with such criteria in nearly all patients (90%). MRI findings closely agreed with the clinical follow-up. CT findings clearly differed from those observed by SPECT and MRI. After second line therapy, 10 patients progressed, 3 had stable disease and 7 had partial response. 201Tl SPECT agreed with the clinical status in 89% cases, whereas MRI and, specially CT, fared significantly lower. CONCLUSION: Compared to conventional neuroimaging, 201Tl SPECT added valuable information in the assessment of the response to therapy in our patient population; whenever findings were not conclusive and in the case of disagreement between CT and MRI findings.

Adult↗

[Results of C1-C2 transarticular screw fixation in a series of 20 patients].

OBJECTIVE: C1-C2 transarticular fixation is an increasingly used surgical method of treating atlantoaxial instability. When properly performed, it can safely provide fusion rates near 100%, but techniques of fixation in this region allow only a small margin of error. We here report the results of C1-C2 transarticular fixation in a series of 20 patients in which different procedures were selected according to the presenting disorder in each case. METHODS: The study group included 9 men and 11 women with a mean age of 48 years (range 17 to 68 years). The causes of instabilities were rheumatoid arthritis in nine patients, type II and III Hangman's fracture of traumatic origin in nine (in association with other lesions in three cases), pseudoarthrosis after type II odontoid fracture in one, and type III complex C1 fracture in a patient with ankylosing spondylitis. Preoperative assessment included flexion and extension plain radiographs and computed tomography (CT) and magnetic resonance imaging (MRI) scans. Operations included transarticular screw fixation in all cases; in patients with rheumatoid arthritis it was associated with sublaminar fixation and bone grafting following Sonntag's technique in all but two cases. Postoperative results were evaluated in relation to the biomechanical stability and fusion was studied by flexion and extension radiographs and CT scans. Pain relief in patients with rheumatoid arthritis patients was assessed using a 0-10 visual analogic scale (V.A.S.). RESULTS: In the traumatic group, a consolidation of the fracture and radiologic stability was achieved in all cases. In patients with rheumatoid arthritis, pain improved in all but not the neurological deficit, and in all cases a C1-C2 biomechanical stability was reached despite interlaminar graft resorption in two (25%) cases. With respect to complications, a lesion of the vertebral artery occurred in one case, deviation of the screw in two cases, and breakage of the screw without clinical repercussion in two other cases. CONCLUSION: C1-C2 transarticular screw fixation was a useful technique to achieve satisfacory biomechanical stability in patients with atlatoaxial instability of both inflammatory and traumatic origin with a low rate of complications.

Adolescent↗

A prospective study of rural drinking water quality and acute gastrointestinal illness.

BACKGROUND: This study examined the relationship between the bacteriological contamination of drinking water from private wells and acute gastrointestinal illness (AGII), using current government standards for safe drinking water. METHODS: A prospective cohort study was conducted using 235 households (647 individuals) randomly selected from four rural hamlets. Data were collected by means of a self-administered questionnaire, a self-report diary of symptoms and two drinking water samples. RESULTS: Twenty percent of households sampled, had indicator bacteria (total coliform or Escherichia coli (E. coli)) above the current Canadian and United States standards for safe drinking water. No statistically significant associations between indicator bacteria and AGII were observed. The odds ratio (OR) for individuals exposed to E. coli above the current standards was 1.52 (95% confidence interval (CI), 0.33-6.92), compared to individuals with levels below current standards. The odds ratio estimate for individuals exposed to total coliforms above the current standards was 0.39 (95% CI, 0.10-1.50). CONCLUSIONS: This study observed a high prevalence of bacteriological contamination of private wells in the rural hamlets studied. Individual exposure to contaminated water defined by current standards may be associated with an increased risk of AGII.

Acute Disease↗

A comparison in monkeys of (99m)Tc labeled to a peptide by 4 methods.

UNLABELLED: Although a number of different strategies for labeling peptides with (99m)Tc have been developed, only a few studies have compared the in vivo properties of (99m)Tc when attached to different chelators. Furthermore, these comparisons are usually in mice, whereas results obtained in nonhuman primates may be expected to be more relevant to the clinical situation. METHODS: We evaluated the influence of 4 common chelators on the biodistribution in monkeys of (99m)Tc-labeled HNE-2, a 6.7-kDa peptide being investigated as an inflammation/infection imaging agent. The peptide was conjugated with the N-hydroxysuccinimide ester of mercaptoacetyltriglycine (MAG3), mercaptoacetyltriserine (MAS3), hydrazinonicotinamide (HYNIC), and the cyclic anhydride of diethylenetriaminepentaacetic acid (DTPA). After radiolabeling, each peptide was administered intravenously to rhesus monkeys with a Staphylococcus aureus-induced focal inflammation/infection. RESULTS: Quantification of radioactivity accumulation by regions of interest over 3 h after administration in monkeys showed important differences among labeling methods: For example, at 3 h, kidney accumulation varied in percentage injected dose per organ (%ID per organ) from 31 %ID per organ (HYNIC) to 18 %ID per organ (MAG3), whereas liver varied from 7.8 %ID per organ (MAG3) to 2.8 %ID per organ (MAS3). Radioactivity accumulation in the lesion was independent of labeling method. These organ accumulations were compared with that obtained earlier in mice by sacrifice and dissection also at 3 h and at the same administered dosage. In the rodent, kidney levels varied from 45 %ID per organ (HYNIC) to 12 %ID per organ (MAS3) and liver levels varied from 6.5 %ID per organ (DTPA) to 2.0 %ID per organ (MAS3). CONCLUSION: In agreement with previous work from this laboratory and elsewhere, the method of radiolabeling had an important effect on the biodistribution of (99m)Tc. Furthermore, although biodistribution results in mice should be used with caution to predict biodistributions in primates, in major organs, these results in mice and monkeys were similar.

Animals↗

Evaluating the outcome of severe head injury with transcranial Doppler ultrasonography.

The authors conducted a study to determine the value of transcranial Doppler (TCD) ultrasonography in evaluating the outcome of severely head injured patients and to correlate the TCD values with those obtained from intracranial pressure (ICP) and cerebral perfusion pressure (CPP) monitoring. The authors conducted a prospective study of 125 patients with severe head injury (Glascow Coma Scale scores of less than 9) who underwent TCD ultrasonography according to the standard technique of insonating the middle cerebral artery (MCA) and measuring the mean blood flow velocity and pulsatility index within the first 24 hours of admission. The ICP and CPP values, as well as other clinical, analytical, and neuroimaging data, were also recorded. After 6 months, outcome was evaluated using the Glasgow Outcome Scale. Moderate disability and complete recovery were considered "good" outcome; death, vegetative state, and severe disability were considered "poor." In 67 patients (54%) good outcome was demonstrated whereas in 58 (46%) it was poor. The mean blood flow velocity of the MCA in patients with good outcome was 44 cm/second; in those with poor outcomes it was 36 cm/second (p < 0.003). The mean PI in cases of good outcome was 1 whereas in poor outcome was 1.56 (p < 0.0001). The correlations of ICP and CPP to PI were statistically significant (r2 = 0.6; p < 0.0001). When performed in the first 24 hours of severe head injury, TCD ultrasonography is valid in predicting the patient's outcome at 6 months and correlates significantly with ICP and CPP values.

Adolescent↗

Treatment programmes for people with both severe mental illness and substance misuse.

BACKGROUND: Substance misuse in the context of severe mental illness can have detrimental effects. A variety of treatments exist, but the drive has been to provide programmes integrating treatment of both substance misuse and severe mental illness. Such programmes require additional resources and may require radical redesign of service delivery systems. OBJECTIVES: To evaluate the effectiveness of treatment programmes within psychiatric care for people with problems of both substance misuse and serious mental illness. SEARCH STRATEGY: Biological Abstracts (1985-1998), CINAHL (1982-1998), The Cochrane Library (Issue 3, 1998), The Cochrane Schizophrenia Group's Register of trials (August 1998), EMBASE (1980-1998), MEDLINE (1966-1998), PsycLIT (1974-1998) and Sociofile (1974-1998) were comprehensively searched. Citations of all trials were searched and further studies sought from published trials and their authors. SELECTION CRITERIA: All randomised trials of any programme of substance misuse treatment for people with serious mental illness and current problems of substance misuse. DATA COLLECTION AND ANALYSIS: Citations and, where possible, abstracts were independently inspected by reviewers, papers ordered, re-inspected and quality assessed. Data were also independently extracted. For homogeneous dichotomous data the Peto odds ratio (OR), and 95% confidence intervals (CI) were calculated on an intention-to-treat basis. MAIN RESULTS: Six relevant studies, four of which were small, were identified. In general, the quality of design and reporting was not high. Clinically important outcomes such as relapse of severe mental illness, violence to others, patient or carer satisfaction, social functioning and employment were not reported. There is no clear evidence supporting an advantage of any type of substance misuse programme for those with serious mental illness over the value of standard care. No one programme is clearly superior to another. REVIEWER'S CONCLUSIONS: The problems posed by substance misuse in the context of severe mental illness will not go away. The current momentum for integrated programmes is not based on good evidence. Implementation of new specialist substance misuse services for those with serious mental illnesses should be within the context of simple, well designed controlled clinical trials.

Comorbidity↗

Role of CD44 in the invasiveness of glioblastoma multiforme and the noninvasiveness of meningioma: an immunohistochemistry study.

CD44 is a polymorphic family of cell adhesion molecules that seems to be instrumental in the mechanism of tumor invasion and metastasis. Tumor cell expression of CD44, or lack thereof, may be one of the factors conditioning the highly disparate ability to penetrate the brain extracellular matrix (ECM) exhibited by glioblastoma multiforme (GM) and conventional meningioma. To assess the presence of CD44 in these two tumor types we have immunohistochemically investigated the expression of CD44 standard form (CD44s) and the variant isoforms containing the domain encoded by variant exon 3 (CD44v3) and variant exon 6 (CD44v6) in paraffin-embedded tissue from 10 conventional meningiomas and 10 GMs. A CD44s-/CD44v-phenotype was discerned in the meningioma cases, whereas GMs featured a CD44s+/CD44v- expression profile. Consequently, the growth patterns of meningioma and GM seem to be, at least in part, a reflection of their CD44 expression status. Paucity of CD44 in meningioma cells would render them unable to infiltrate the brain ECM, whereas CD44-rich glioma cells would successfully migrate through it. Conversely, lack of CD44v expression would contribute to explain the lack of metastatic potential characterizing both conventional meningioma and GM.

Adult↗

Measurement of psychological distress in asthma and asthma management programmes.

The Asthma Bother Profile assesses one of the components of asthma experience: asthma distress. An initial questionnaire was constructed from the content of earlier asthma quality of life research and modified by comments of 32 asthmatics in focus groups. Psychometric analysis of responses of 131 asthmatics to the final questionnaire showed that the 15 ¿bother items' constitute a unidimensional measure of asthma distress with high internal consistency, and the seven ¿management items' assess the patient's confidence of asthma knowledge, perception of the quality of care and confidence in managing asthma attacks. Patients who had attended a self-management clinic reported more knowledge of asthma, more bother from treatment but not significantly less bother in other contexts. Knowledge about when to call the doctor but not knowledge about medicine or asthma was correlated with total bother. Self-management programmes that encourage problem-focused coping strategies may not reduce asthma distress unless distress reduction counselling is included within the education programme.

Adaptation, Psychological↗

Comparative evaluation of modified m-FC and m-TEC media for membrane filter enumeration of Escherichia coli in water.

Two media used to detect fecal coliforms in water by membrane filtration, m-FC and m-TEC, were modified and supplemented with the chromogenic substrate 5-bromo-6-chloro-3-indoyl-beta-D-glucuronide (BCIG) and were compared for quantitative recovery of Escherichia coli. Student's t test of data from 181 water samples of sewage, rivers, lakes, and wells did not demonstrate any statistically significant differences (P = 0.05) in the enumeration of E. coli with these media. Target colonies were confirmed to be E. coli at rates of 98.6 and 97.3% by using FC-BCIG and TEC-BCIG media, respectively. Glucuronidase-negative isolates of E. coli were encountered at the same frequency (6.0%) on both media. This collaborative study demonstrated that either modified basal medium could be used successfully for detection of E. coli in various nontreated waters within 24 h.

Colony Count, Microbial↗

Use of 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside for the isolation of beta-galactosidase-positive bacteria from municipal water supplies.

A new medium, mX-Gal, has been developed for the membrane filter enumeration of beta-galactosidase-positive bacteria in municipal water supplies. mX-Gal medium contains the chromogenic beta-galactosidase substrate 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal). All Aeromonas, Citrobacter, and Enterobacter strains isolated from raw water on mX-Gal medium were beta-galactosidase positive. In contrast, only 10 to 20% of these strains produced a red colony with a metallic sheen on m-Endo agar LES medium. Of 674 chlorinated water samples analyzed for total coliforms on m-Endo agar LES medium and for beta-galactosidase-positive bacteria on mX-Gal medium, 18 that were negative for coliforms on m-Endo agar LES showed beta-galactosidase-positive bacteria on mX-Gal. Of a total of 50 beta-galactosidase-positive bacteria isolated from these samples, 76% were identified as Aeromonas hydrophila.

Aeromonas↗

Inhibition of methanogenesis in pure cultures by ammonia, fatty acids, and heavy metals, and protection against heavy metal toxicity by sewage sludge.

The effect of ammonium chloride, sodium butyrate, sodium propionate, and the heavy metals nickel, zinc, and copper on methanogenesis by pure cultures of Methanospirillum hungatei, Methanosarcina barkeri, Methanobacterium thermoautotrophicum, and Methanobacterium formicicum at pH 6.5 was studied. The latter three strains were resistant to greater than 60 g/L of the volatile fatty acids and to greater than 10 g/L of NH3 N. Methanospirillum hungatei was somewhat more sensitive with 50% inhibition of methanogenesis occurring at 4.2 g/L NH3 N, 27 g/L butyrate, and 41 g/L propionate. All strains were very sensitive to both copper (1-5 mg/L) and zinc (1-10 mg/L), but much more resistant to nickel. Zinc and copper concentrations 30 to 270 times higher were required to cause inhibition of Msp. hungatei incubated in sewage sludge compared with buffer, indicating a strong protective environment was afforded the methanogens against heavy metal toxicity in the sludge.

Ammonium Chloride↗

Evidence for Cyclic Electron Flow around Photosystem II in Chlorella pyrenoidosa.

Electron flow around photosystem II was investigated in Chlorella pyrenoidosa. Using a bare platinum O(2) electrode, simultaneous measuremnts were made of steady-state photosynthesis in continuous light, the yield of oxygen (Y(o(2) )) produced by a superimposed saturating xenon flash, and the change in fluorescence yield of a weak flash triggered before and 70 microseconds after the saturating flash. Throughout most of the continuous photosynthesis-irradiance curve, normalized O(2) flash yields (Y(o(2) )/Y(o(2)max)) and normalized variable fluorescence yields (Deltaphi/Deltaphi') were linearly correlated with a slope of 1.0. As photosynthetic rates reached light saturation, however, the variable fluorescence yields remained relatively constant while O(2) flash yields decreased. These results strongly suggest that there is a cyclic electron flow around photosystem II in unpoisoned intact cells at light saturation and supraoptimal light intensities.

Journal Article↗

Incidence of clinical infections in a defined population of pregnant women.

The incidence of clinical maternal infections was determined in a prospective study of 44,016 pregnant women at 12 university hospitals. Viral and bacterial infections were the most frequently reported. Overall, the highest incidence of infections was for vaginitis, influenza/"flu"-like disease, and infections of the kidney, ureter, bladder; parasitic and fungal infections occurred at low rates. Most women experienced only one infection during pregnancy (89.7%); however, some had two different infections (8.5%), and a few had three or more (1.7%). The analysis of the effects of some of the maternal infections on the pregnant women and their children have been published, and further studies are in progress.

Black or African American↗

Comparison of hemagglutination inhibition test and enzyme-linked immunosorbent assay for determining antibody to rubella virus.

The hemagglutination inhibition test (HAI) and the enzyme-linked immunosorbent assay (ELISA) for detecting antibody to rubella virus were compared by testing 25 sets of paired sera taken before and after infection and 10 sets of sera taken during acute and convalescent stages of the disease and by screening 700 serum samples from the Collaborative Perinatal Project, NIH/NINCDS. The tests were found to be comparable in their ability to detect positive and negative sera, rises in titers, and seroconversions. When a purified antigen and carefully prepared reagents were used, ELISA was found to be as accurate and reliable as HAI. ELISA required no pretreatment of serum, could easily be automated, and was less time-consuming than HAI.

Antibodies, Viral↗