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The rational use of antibiotics in the treatment of brain abscess.

The Working Party was instituted to investigate the rationale of therapeutic antibiotic usage in patients with brain abscess and to make recommendations for current practice. A systematic review of English language publications on brain abscess over the last 25 years was carried out using electronic databases and secondary sources, and data were evaluated. Few publications were identified where the microbiological procedures were adequately described and many authors continue to report sterile pus in a proportion of cases. The vast majority of reports were retrospective neurosurgical assessments in which details of laboratory procedures and antibiotic regimens were missing. There are no published reports of controlled clinical trials or comparative therapeutic studies. The recommendations made by the Working Party are based on relevant published information and the expertise of Working Party members. Recommendations vary according to the location of the abscess which reflects the likely source of the infection and therefore the bacterial types most likely to be present in aspirated pus. Bacteria with multiple resistance to antimicrobial agents do not feature significantly in cases of brain abscess.

Anti-Bacterial Agents↗

Good clinical practices in phase I studies.

In France, official guidelines for good clinical practices in clinical trials were issued in 1987. In December 1988, a law was passed that fixed the requirements for carrying out experiments in healthy subjects. It will be completed by official guidelines for the structures in which experiments on healthy subjects (and patients as well, when the investigation would not benefit the health of the patients) may be conducted. Hence a battery of recent legal instructions precisely state what good clinical practices are in the setting of phase I studies. Of particular importance are: subject recruitment and selection methods and procedures; specific competence of the investigator, in particular to interpret the pre-trial data; necessary and sufficient facilities to guarantee the subjects' safety; careful quality control to check all laboratory procedures; necessity of written standard operating procedures.

Drug Evaluation↗

Intra- and interlaboratory sources of imprecision in drug measurements by different techniques.

We compared the intra- and interlaboratory precision of seven techniques used to measure eight antiepileptic drugs, digoxin, and theophylline by using data from the international Healthcontrol external quality-assessment scheme. Scheme participants were supplied blind with 6 or 12 sets of duplicate lyophilized serum samples. Each set contained different drug concentrations, and duplicates were analyzed separately, 1 to 6 months apart. The intra- and interlaboratory components of assay variance were isolated and compared by Bartlett's test for homogeneity of variance. Fluorescence polarization immunoassay (Abbott) showed the best overall intra- and interlaboratory performance for a range of analytes. The largest intralaboratory errors were produced by techniques using the Syva EMIT assays. Our analysis of the data shows that for most analyte/technique combinations, intralaboratory sources of variation were more important than interlaboratory sources. Gains in assay precision will therefore result from attention to internal laboratory procedures.

Anticonvulsants↗

Necropsy of chickens, turkeys, and other poultry.

Necropsy of dead or terminally ill birds is a key approach to disease diagnosis. It is important that one establish an orderly, consistent necropsy procedure and evaluate gross lesions as to their likely cause and significance. A very high percentage of farm flock poultry maladies can be diagnosed by gross lesions plus a few simple laboratory procedures, such as direct microscopy, Gram's stain, fecal flotation, and aerobic bacteriology.

Animals↗

Feasibility of paramedic treatment and referral of minor illnesses and injuries.

BACKGROUND: Approximately 40% of Hennepin County Medical Center's (HCMC's) ambulance runs are for minor medical conditions as defined by billing criteria ["ALS minor," i.e., no advanced life support (ALS) procedures done in the field]. Current metropolitan guidelines mandate that all such patients must be transported to a hospital unless they refuse this service. It has been proposed that some patients with minor medical conditions could be better served by treatment in the field by paramedics and referred to a clinic or hospital for early follow-up care. It is proposed that this approach would save costs and improve paramedic availability for patients with more serious conditions. OBJECTIVE: To evaluate the feasibility and safety of implementing such a program by identifying high-volume, low-complexity groupings of cases. Such high-volume, low-complexity cases would serve as the topics for curriculum development for paramedic training in field treatment and referral. METHODS: Data were obtained from ambulance run sheets and emergency department (ED) records for all patients transported by the HCMC ambulance service in 1996 who were covered by the Metropolitan Health Plan (MHP) and who were categorized for billing purposes as "ALS minor" transports. The data included demographic information, vital signs, presenting problem, diagnoses in the ED, and procedures, laboratory studies, or x-rays done in the ED. Patients were classified as "potentially treatable" in the field if they were treated and discharged from the ED without undergoing any procedures or diagnostic studies. Patients who required more extensive evaluation in the ED, or who were admitted, were classified as likely too "complex" to be treated at the scene and then referred for early follow-up. The data were analyzed to find the most common presenting problems and the numbers, characteristics, and dispositions of "potentially treatable" and "complex" patients in each group. This information was used to determine what, if any, types of patients could potentially be treated safely and effectively according to this scheme. RESULTS: The study group comprised 1,103 patients, representing 127 different presenting medical problems. There were 523 (47%) "potentially treatable" patients and 580 (53%) "complex" patients. The 127 medical problems were grouped and the 15 most common presenting problem groups were identified. Within these groups there was no single medical problem with high volume. Each of these 15 most common problem groups contained a substantial proportion of "complex" patients, ranging from 24% to 100%. CONCLUSIONS: None of the 15 most frequently encountered problem groups consisted of a high enough proportion of "potentially treatable" cases to serve as a high-volume, low-complexity category for paramedic treatment in the field with early follow-up. Without any identified high-volume, low-complexity categories, a treatment and referral program as proposed in this article would require a substantial investment in development of appropriate criteria and in training paramedics to apply the criteria for numerous clinical entities. This would limit any cost saving, and require great care to avoid compromising patient safety accompanied by substantial professional liability exposure.

Ambulances↗

[Occlusal adjustment and crown finishing in gold-ceramics].

In the present study the Authors, using the Scanning Electron Microscope (magnification max. = 1.500 X), compare the finishing of gold-porcelain crown's surfaces clinically obtainable, after finishing by diamond points, with the polishing realized by means of glazing laboratory procedures. The survey demonstrates a great difference between the two techniques, showing large furrows on the surfaces when polished using silicon rubber points while they were perfectly smooth when glazed in laboratory.

Crowns↗

A laboratory batch reactor test for assessing nonspeciated volatile organic compound biodegradation in activated sludge.

The relative rates of biodegradation and stripping and volatilization of nonspeciated volatile organic compounds (VOCs) in wastewater treated with aerobic activated-sludge processes can be quantified using a newly developed procedure. This method was adapted from the original aerated draft tube reactor test that was developed to measure biodegradation rate constants for specific volatile pollutants of interest. The original batch test has been modified to include solid-phase microextraction (SPME) fibers for sampling in the gas phase. The experimental procedure using SPME fibers does not require specific identification and quantitation of individual pollutants and can be used to evaluate wastewater with multiple VOCs. To illustrate use of this procedure, laboratory experiments were conducted using biomass and wastewater or effluent from three activated-sludge treatment systems. Each experiment consisted of two trials: a stripping-only trial without biomass and a stripping plus biodegradation trial using biomass from the activated-sludge unit of interest. Data from the two trials were used to quantify the rates of biodegradation by difference. The activated-sludge systems tested were a laboratory diffused-air reactor treating refinery wastewater, a full-scale surface aerated reactor treating a petrochemical wastewater, and a full-scale diffused-air reactor treating a variety of industrial effluents. The biodegradation rate constant data from each laboratory batch experiment were used in model calculations to quantify the fraction emitted (fe) and the fraction biodegraded (fbio) for each system. The fe values ranged from a maximum of 0.01 to a maximum of 0.32, whereas fbio values ranged from a minimum of 0.40 to a minimum 0.95. Two of these systems had been previously tested using a more complicated experimental approach, and the current results were in good agreement with previous results. These results indicate that biodegradation rate constant data from this laboratory method can be successfully used to predict the fate of VOCs in field-scale treatment units, and thus could potentially be used for demonstration of compliance with wastewater VOC emission regulations.

Biodegradation, Environmental↗

Evaluation of three commercially available blood culture systems for cultivation of Helicobacter pylori.

Helicobacter pylori is unable to grow in regular blood culture systems, including the BACTEC (Johnston Laboratories), Septi-Chek (Hoffman-La Roche), and Bacto (Difco) systems. We tested three blood culture systems used for fastidious organisms: brucella broth with SPS and CO2 (Becton Dickinson), biphasic brain heart infusion agar or broth (Becton Dickinson), and supplemented peptone broth (Vacutainer). Blood culture bottles were inoculated with H. pylori and human blood and were then incubated by routine diagnostic laboratory procedures. All three blood culture systems were able to sustain the growth of H. pylori, but brucella broth had the highest CFU per milliliter after 72 h. We conclude that a diagnostic laboratory should be able to detect H. pylori bacteremia in a majority of cases by using brucella blood culture bottles.

Animals↗

Bioterrorism-related anthrax: international response by the Centers for Disease Control and Prevention.

After reports of the intentional release of Bacillus anthracis in the United States, epidemiologists, laboratorians, and clinicians around the world were called upon to respond to widespread political and public concerns. To respond to inquiries from other countries regarding anthrax and bioterrorism, the Centers for Disease Control and Prevention established an international team in its Emergency Operations Center. From October 12, 2001, to January 2, 2002, this team received 130 requests from 70 countries and 2 territories. Requests originated from ministries of health, international organizations, and physicians and included subjects ranging from laboratory procedures and clinical evaluations to assessments of environmental and occupational health risks. The information and technical support provided by the international team helped allay fears, prevent unnecessary antibiotic treatment, and enhance laboratory-based surveillance for bioterrorism events worldwide.

Anthrax↗

The laboratory report: a problem in communication between clinician and microbiologist?

When writing a laboratory report, the microbiologist often makes certain assumptions as to the clinician's understanding of laboratory procedures and reporting practices. The effect of these assumptions on the interpretations of the reports is discussed, with data from a survey of general practitioners. Possible ways of improving communication between the laboratory and the clinician are suggested.

Bacteriology↗

Laboratory identification of familial thrombophilia: do the pitfalls exceed the benefits? A reassessment of ABO-blood group, gender, age, and other laboratory parameters on the potential influence on a diagnosis of protein C, protein S, and antithrombin deficiency and the potential high risk of a false positive diagnosis.

Laboratory testing for familial thrombophilia defines a large proportion of the modern hemostasis laboratory workload. As part of an ongoing assessment of our activities, we have re-evaluated our laboratory procedures for antithrombin (AT), Protein C (PC), and Protein S (PS), inclusive of normal reference ranges (NRR), the potential influence of ABO-blood group, gender and age, as well as other laboratory parameters, in order to help assess the effectiveness of testing as an aid to clinical diagnosis. We did not observe a significant influence of ABO-blood group on AT, PC, or PS. However, there were gender-related effects for PS (lower in females) and AT (higher in females), but not for PC. There were also age-related effects for AT, PC, and PS. Data is compared with literature findings. We also audited the positive detection rate for PC and/or PS deficiencies. In a 6-month period of testing, we identified that 18.9% of tested samples yielded low or near-low PC and/or PS levels. However, 33.3% of such samples were potentially derived from patients on oral anticoagulant therapy (ie, potential false positives). Additional pre-analytical variables, intra-assay, inter-assay, and inter-laboratory variability also contribute to the possibility of false positive detection. Thus, whilst NRR can be developed for test parameters, the likelihood of a false-positive test result can still be shown to exceed the likelihood of a true positive result, and this casts a shadow over the clinical value of such testing in some cases. In conclusion, laboratory testing for these markers of familial thrombophilia may or may not assist in the clinical diagnosis of this condition and clinical specialists should be made aware of laboratory test limitations, and consult with laboratories prior to making a definitive diagnosis of AT, PC, or PS deficiency.

ABO Blood-Group System↗

Procedure for obtaining proper contour of an implant-supported crown: a clinical report.

Achieving proper contour of an implant-supported crown is essential for an esthetic result, particularly in the maxillary anterior area. Development of the soft tissue profile prior to the initiation of laboratory procedures is the ideal approach. This article describes a procedure that makes use of a soft tissue cast to permit crown fabrication prior to intraoral soft tissue customization.

Adult↗

Initial evaluation of patients with hypertension: an office procedure.

Traditionally the initial evaluation of a patient with high blood pressure has focused on exluding secondary correctable causes of hypertension. Such all-inclusive evaluations are expensive, time-consuming, and expose the patient to some risk. A complete history, physical examination, and relatively simple laboratory procedures such as CBC, urinalysis, SMA-6 and 12, and ECG yield sufficient information to detect damage to target organs caused by elevated blood pressure and to exclude the presence of secondary causes fairly adequately. In that small number of patients in whom clues for correctable causes of hypertension are uncovered, or if patients fail to respond to appropriate treatment for essential hypertension, a more extensive evaluation can be undertaken.

Auscultation↗

[Contribution to the determination of thallium in human head hair in forensic cases with flameless atomic absorption spectrometry].

Among various procedures for the determination of thallium as a toxic element, micro-techniques by means of flameless AAS play an important role in hair analysis. Referring to two cases of T1-intoxication laboratory procedures, techniques and instrumentation are reported, which prove to be useful, sensitive, and fast. Considerations concerning sample preparation, contamination problems and compensation of spectral background effects by a duochannel spectrophotometer are discussed.

Adult↗

The use of gamma-glutamyl transpeptidase in differentiating liver from bone isoenzymes of alkaline phosphatase.

Sixty-one patients with elevated alkaline phosphatase activity due to liver or bone diseases were studied. An attempt was made to identify the origin of the increased alkaline phosphatase by chemical inhibition, by inactivation by heat and urea, and by electrophoretic separation. The results obtained from these procedures were correlated with the gamma-glutamyl transpeptidase activities performed on each patient. We concluded from this study that gamma-glutamyl transpeptidase determination, together with alkaline phosphatase electrophoretic separations, are useful laboratory procedures for accurately identifying the origin of elevated alkaline phosphatase activity.

Alkaline Phosphatase↗

Forensic science does not start in the lab: the concept of diagnostic field tests.

An attempt to improve an analytical system can focus either on the actual processing or on the input. In forensic science, much emphasis has been placed on improving laboratory procedures, as though the input is already the best that can be obtained. Means of improving the basic input have gained much less attention. Yet, it must be agreed that even the best laboratory cannot gain from an item more than has been contained in it when it arrived from the field. The detection of latent materials at the crime scene by physical or chemical techniques and the diagnostic examination of material already discovered belong to the concept of diagnostic field tests. This group also includes "mapping" for the presence of certain materials, such as latent fingerprints through the distribution of amino acids on the surface. These tests are conducted outside the laboratory, without sophisticated instrumentation, at the crime scene, the suspect's home, or elsewhere. A significant advantage of the use of diagnostic field tests is the ability to deal with "dissipating evidence" such as gunshot residue or explosive traces on the hands of suspects. If time is lost, there is a risk of losing such evidence, which is liable to deteriorate rapidly. In my presentation, I will discuss older and some newly developed forensic field tests, with specific emphasis on the Israeli experience.

Awards and Prizes↗

Laboratory identification of aeromonads from man and other animals.

Forty-eight isolates of aeromonads from clinical specimens were studied. The laboratory procedures employed and the results obtained are reported in the hope that they may be of assistance to other workers in the field of diagnostic microbiology. Capability of identifying these organisms in the laboratory will contribute to a better understanding of the role of this group of organisms in human disease as well as in diseases in other animals.

Aeromonas↗

[Evaluation of frozen sections and cytological diagnosis during surgery].

When a surgeon feels it to be necessary to carry out morphological diagnosis during the operation, the pathologist may assist him or her with rapid cell or tissue diagnosis. This must be a conscious decision to introduce an additional step into the chain of laboratory procedures from the taking of the sample to the reporting of the result. Because this additional phase requires a longer stay in the operating room and additional effort on the part of the laboratory staff, together with an increased risk of misclassification of the disease process, this step should only be taken after careful consideration of the pros en cons. On the one hand, the need for intra-operative diagnosis has decreased because of the availability of better and more accurate pre-operative diagnostic techniques; on the other hand, there are new developments such as the introduction of sentinel-node biopsy, in which one must weigh the advantages of a rapid intra-operative diagnosis against the slower but surer results of a more comprehensive lymph-node investigation. Routine examination of the cut edges during an operation is hardly ever done any longer as a result of changed biological knowledge regarding the margins needed for radical surgery.

Biopsy↗