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Biomedical subjects

M G Scott

Publications and source records attributed to M G Scott.

At least 19 recordsLinked to original sources
PubMed1995

Audit of antibiotic usage in medium-sized general hospital over an 11-year period. The impact of antibiotic policies.

The objective of the present study was to evaluate trends in antibiotic expenditure over an 11-year period (1982-1992) in a 370-bed district general hospital in Northern Ireland and to examine the impact of two separate antibiotic policies on antibiotic usage. A further objective was to examine the attitudes of prescribers to the second policy. Drug utilization review was used to collect information on antibiotic expenditure and usage before and after introduction of separate antibiotic policies in 1985 (not intensively monitored) and 1989 (intensively monitored). A main questionnaire was used to determine the attitudes of prescribers. The first policy (1985) showed no benefits with regard to the number of antibiotic entities stocked (45 before, 45 after), number of dosage units issued (9.3% increase) or expenditure (33.3% increase). The 1989 policy led to significant reductions in the number of antibiotic entities stocked (28.9%), number of antibiotics issued (11.9%) and expenditure (6.1%). Expenditure began to spiral upwards when active monitoring of the second policy was suspended. The majority of prescribers (87.2%) who responded to the questionnaire (56.5% response rate) felt that the 1989 policy made a positive contribution to antibiotic usage in the hospital.

Anti-Bacterial Agents↗
PubMed1995

Current status of US programs for training clinical laboratory scientists and anticipated impact of healthcare reform.

We surveyed directors of medical technology (MT) and postdoctoral clinical chemistry (CC) training programs and of clinical pathology (CP) and combined anatomic/clinical pathology (AP/CP) residency programs regarding the number, quality, training emphasis, and job-placement experience of trainees for 1985-95 as well as the directors' opinions on the impact of "healthcare reform." Responses were received from directors of 94 of 249 (38%) MT programs, 14 of 15 (93%) CC programs, and 63 of 138 (46%) pathology residency programs. In all four categories the numbers of trainees have increased steadily over the last 5 to 7 years but are expected to remain stable or decrease slightly. Directors of MT and CC programs expect increasing difficulty placing their graduates; directors of AP/CP and CP residency programs do not. Although > 60% of MT graduates have entered private hospitals, this is anticipated to decrease, with a concomitant increase in university hospital placements. Of the AP/CP residents, > 60% and < 5% accepted service- and research-oriented positions, respectively. In contrast, 83% of CP residents entered university hospitals, with half of these taking research-oriented positions. Among CC graduates, 41% joined university hospitals and 10-15% accepted positions in each of either private hospitals or industry or reference laboratories. The emphasis of training varies, with clinical service and pathophysiology the major focus in AP/CP programs. CP and CC programs take two distinct approaches--some accentuating management, and others emphasizing research. Finally, MT program directors appear the most optimistic regarding the opportunities that healthcare reform may present.

Chemistry, Clinical↗
PubMed1995

Clinical utility of biochemical analysis of cerebrospinal fluid.

In addition to microbial culture, cytology, and immunological studies, physicians rely on the clinical chemistry laboratory for biochemical analysis of patients' cerebrospinal fluid (CSF). However, apart from routine glucose and protein determinations, the clinical value of other CSF analytes is often unclear. Here, we review the literature pertaining to the use of CSF biochemical measurements in managing patients with infectious disease, neoplasia, stroke and trauma, and dementia. Although a small number of studies demonstrate potential usefulness of some markers, we conclude that, without further study, the data are insufficient to support the routine clinical use of most of the analytes examined.

Central Nervous System Neoplasms↗
PubMed1994

Evaluation of a new colorimetric assay for serum lithium.

Using patient samples (n = 175) collected in our clinical chemistry laboratory, we have undertaken an analysis of a new colorimetric dry slide-based serum lithium (Li+) assay from Eastman Kodak for its Ektachem instrumentation series. Analyzer imprecision was acceptable, and good correlation was seen between the Ektachem assay and an ion-selective electrode (ISE)-based assay currently in use in our laboratory (r = 0.99). At all concentrations tested, potassium (K+), triglycerides, or bilirubin did not detectably interfere with the Ektachem determination of Li+. At concentrations within the reference range (135-145 mmol/L), sodium (Na+) did not affect the Ektachem Li+ determination. A slight Na(+)-dependent positive bias in the Li+ determination was evident at 157 mmol/L, but became clinically significant (> or = 0.2 mmol/L) only at physiologically extreme concentrations (> 188 mmol/L) of Na+. Very high concentrations (> 325 mg/dl) of hemoglobin also were found to cause a clinically significant positive bias. We conclude that the determination of Li+ by the Kodak Ektachem is precise, accurate, and adequately free from bias due to common interferents or other monovalent cations, and, therefore, is an acceptable alternative to currently available methods for the monitoring of serum LI+.

Bilirubin↗
PubMed1994

Pulmonary aspiration in mechanically ventilated patients with tracheostomies.

The purpose of this descriptive study was to evaluate feeding aspirations in adult patients receiving long-term mechanical ventilatory support, including the incidence of aspirations, the frequency of silent (clinically inapparent) aspirations, and differences between aspirators and nonaspirators. Aspiration data were determined by review of videofluoroscopic (VF) tapes of modified barium swallow procedures performed on 83 medically stable patients admitted to a chronic ventilator unit. Demographic and clinical variables were obtained from review of subjects' medical records. Forty-two subjects (50 percent) aspirated during VF testing and 37 of 48 (77 percent) aspirations were silent. Subjects who aspirated were significantly older than those who did not aspirate (p = 0.007). Swallowing disorders were common, particularly disturbances of the pharyngeal phase. We conclude that feeding aspiration is seen frequently in patients with tracheostomies receiving prolonged positive pressure mechanical ventilation. Advanced age increases the risk of aspiration in this population. Episodes of aspiration are not consistently accompanied by clinical symptoms of distress to alert the bedside observer to their occurrence.

Adult↗
PubMed1994

Endogenous serum antibodies that interfere with a common thyroid hormone uptake assay: characterization and prevalence.

We identified individuals whose serum contained a substance that produced falsely decreased thyroid hormone (T)-uptake values determined by the Emit (Syva) procedure. Investigation of this interference was prompted by identification of a patient with T-uptake values inconsistent with clinical assessment. IgG depletion and supplementation studies with this patient's serum suggested that the interference was due to endogenous antibodies with specificity for the thyroxine-glucose-6-phosphate dehydrogenase conjugate in the Emit T-uptake assay. The prevalence of the interference was examined by prospectively comparing routine Emit T-uptake values of 1710 patients' samples to T-uptake values obtained by another method. Discrepant samples were also assayed by a radioactive binding triiodothyronine-uptake assay. We identified eight samples that had falsely decreased T-uptake values by Emit, for an overall prevalence of 0.46%. Among 45 consecutive patients with a T-uptake value < 20%, five patients, or 11%, were falsely decreased by Emit and three of these were clearly due to an interfering IgG. We suggest that samples with abnormally low T-uptake values determined by the Emit method be confirmed by an alternative method.

Adult↗
PubMed1994

Interference in ionized calcium measurements by heparin salts.

We determined the suitability of various heparin salts used for anticoagulation of whole-blood specimens for measurement of ionized calcium (iCa), blood gases, and electrolytes. We were particularly interested in a new heparin product containing both zinc and lithium cations (CNLZ heparin), in which the binding sites with greatest affinity for divalent cations are bound with zinc and low-affinity sites with lithium. In initial experiments Li heparin decreased iCa concentrations 0.07 mmol/L at the lowest heparin concentration (3000 units/L) and progressively lowered them at higher concentrations. Zn heparin initially increased iCa concentrations 0.06 mmol/L but progressively lowered them as the heparin concentration was increased. Li heparin interfered even when present in amounts (9 units per 3-mL syringe) minimally effective in preventing coagulation. Use of CNLZ heparin (36 units per 3-mL syringe; Zn 63-78 g/kg of heparin) largely eliminated interference of heparin in iCa measurements. In studies that included the effects of concentration of heparin through partial filling of syringes, specimens anticoagulated with CNLZ heparin compared well with unheparinized controls in measurements of iCa, blood gases, and electrolytes. Blood gases and iCa results on CNLZ-heparinized specimens from intensive-care-unit patients also compared well with specimens anticoagulated with a preparation of heparin (EB heparin) in which calcium has been added to balance the calcium-binding capacity. However, the presence of calcium in EB heparin significantly increased measured total calcium concentrations, whereas the new CNLZ heparin did not interfere in total calcium determinations.

Arteries↗
PubMed1993

Clonal characterization of the human IgG antibody repertoire to Haemophilus influenzae type b polysaccharide. V. In vivo expression of individual antibody clones is dependent on Ig CH haplotypes and the categories of antigen.

Antibodies (Ab) to the polysaccharide capsule of Haemophilus influenzae type b (Hib-PS) provide protection against Haemophilus influenzae type b disease in children, and Hib-PS vaccines with different immunologic properties are widely used clinically. The repertoire of human anti-Hib-PS Ab induced by these vaccines is relatively restricted and can be divided into two types by the structure of the light chain V region. Ab using A2-V kappa II gene product, which account for the majority of anti-Hib-PS Ab response in most patients, show little somatic mutations. In contrast, non-Ab using A2-V kappa II gene product use VL genes from the V kappa I, V kappa II, V kappa III, V kappa IV, and V lambda subgroups, are variably expressed among patients, and contain somatic mutations. To further study the expression of these two types of anti-Hib-PS Ab, we have produced KB13, a mAb specific for V kappa II subgroup, and used mAb specific for various other VL subgroups to develop immunoassays specific for anti-Hib-PS Ab of each VL subgroup. When Ig allotypes were studied for the effect on the Ab repertoire, A2-V kappa II (A2) Ab were found to be expressed less in patients expressing fb or zag CH haplotypes (p < 0.05). When the T cell-independent Hib-PS carbohydrate vaccine was compared to two T cell-dependent Hib-PS protein conjugate vaccines for their effect on Ab repertoire, Ab using V kappa III VL were found to be more often elicited with the conjugate vaccines than with the Hib-PS carbohydrate vaccine (p < 0.01). Thus, individual members of the anti-Hib-PS Ab repertoire differ not only in their V region structure but also in the control of their expression.

Adult↗
PubMed1993

A comparison of Agiolax and lactulose in elderly patients with chronic constipation.

In a double-blind crossover study the efficacies of Agiolax, a combination of fibre and senna pod, and lactulose were compared in 77 long-stay elderly patients with chronic constipation. Mean daily bowel frequency, stool consistency and ease of evacuation were significantly greater with Agiolax than lactulose. The recommended dose was exceeded more frequently with lactulose than Agiolax (chi 2 = 8.38, p < 0.01). Adverse effects were not different for the 2 treatments. In long-stay elderly patients with chronic constipation Agiolax and lactulose were well tolerated, but Agiolax proved a more effective treatment.

Aged↗
PubMed1992

Characterization of the human IgG antibody VL repertoire to Haemophilus influenzae type b polysaccharide.

The human antibody response to the capsular polysaccharide of Haemophilus influenzae type b (Hib) is a good model for examining human V region repertoires. While the VL repertoire of human antibodies to Hib polysaccharide is relatively simple and dominated by the product of a germline V kappa II gene named A2, at least five other VL genes can be expressed by some individuals. These include at least two V kappa I products and at least one V kappa III, one V kappa IV, and one V lambda product. The epitope recognized by a monoclonal anti-idiotype antibody is on the A2 V kappa II product.

Adult↗
PubMed1992

A pharmacokinetic and pharmacodynamic comparison of plain and enteric-coated prednisolone tablets.

1. Eight healthy volunteers and eight patients suffering from chronic obstructive pulmonary disease (COPD) received 30 mg prednisolone as plain (P) and enteric-coated tablets (EP) in a randomised, cross-over manner. Plasma prednisolone and cortisol and blood glucose were measured over 24 h. 2. Although absorption of prednisolone was considerably slower when administered as the enteric-coated form, peak plasma drug concentrations and total AUC (0,24 h) were equivalent for the two formulations. Malabsorption of prednisolone was not observed. 3. The administration of EP was associated with significantly less adrenal suppression in volunteers than P as judged by measurement of AUC (0,24 h) values for endogenous cortisol. However, this difference did not reach statistical significance in the patient group. 4. Plasma cortisol concentrations declined more slowly following administration of the enteric-coated form to both groups. The difference in time taken (median and range) to maximum suppression of cortisol was statistically significant (P less than 0.05) between P (2.5 h; 2-4 h) and EP (4 h; 3-12 h) preparations administered to volunteers. There was a similar significant difference (P less than 0.05) between P (2.5 h; 1-4 h) and EP (7 h; 2-12 h) in the patients. 5. Plasma cortisol concentrations were significantly lower at 24 h in patients receiving the enteric-coated product in association with higher terminal prednisolone concentrations. 6. Blood glucose concentrations increased over an 8 h period in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

The human antibody V region repertoire to the type B capsular polysaccharide of Haemophilus influenzae.

The V region repertoire of the human antibody response to the type b capsular polysaccharide of Haemophilus influenzae (Hib-PS) is being defined at the molecular level using antibodies purified from serum of immunized adults. The VH of this response is restricted to the VHIII subgroup while the VL can be divided into two categories. The most common VL, expressed in > 90% of adults and usually constituting the majority of a subjects anti-Hib-PS antibody response, is restricted to the product of a single V kappa II gene known as A2 that probably lacks somatic mutations. The product of the A2 gene is invariably joined to one of several J kappa products by an inserted arginine at the V kappa-J kappa junction. In contrast to the restricted nature of the dominant VL clonotype, the second category of VL constitutes a heterogeneous group of at least seven different VL gene products that often contain somatic mutations and generally exhibit crossreactivity with a related polysaccharide from E. coli. Elucidation of anti-Hib-PS V regions at the molecular level will permit examination of structure-function relationships among these clinically important antibodies and should make the V region repertoire to Hib-PS a useful model for studying human V gene responses.

Amino Acid Sequence↗