Brainstem evoked potentials for scoliosis surgery: a reliable method allowing use of halogenated anesthetic agents

A predictable and accurate method of monitoring cord function during scoliosis surgery using somatosensory brainstem evoked potentials (SBEP) is described. This method allows the use of halogenated anesthetic agents, which are ideal for neuromuscular patients, but easily disrupt traditional cortical monitoring. Fifty-eight children with idiopathic, neuromuscular, and syndrome related scoliosis were monitored with 51 true negative, one false negative, four true positive and two false positive results. The SBEP method is sensitive and effective for all types of scoliosis surgery, especially neuromuscular scoliosis.

Activity of phospholipase A2 in plasma increases in uremia

We measured phospholipase A2 (PLA2; EC 3.1.1.4) activity in normal and uremic plasma, using [1-14C]oleate-labeled autoclaved Escherichia coli as substrate. Hydrolysis of bacterial phospholipid by crude plasma from both groups was optimal at pH 5.5, was specific for the 2-acyl position of phospholipids, and had an absolute requirement for calcium. Activity was greatest in the presence of added Ca2+, 5 mmol/L, but this increase was inhibited by several divalent cations (Mg2+, Zn2+, Cu2+, Ba2+, Co2+, Pb2+, Fe2+) and by Fe3+. PLA2 activity was also inhibited by heparin at acid and alkaline pH, normal plasma being more sensitive than uremic plasma to this inhibition. Enzyme activity in undiluted plasma was eightfold greater in uremic than in normal plasma. Dilution of plasma by two to fourfold increased the total activity of both normal and uremic plasma. However, the relative differences in total activity between the groups remained constant (eight- to 11-fold). The cause and consequences of the increased PLA2 activity in uremia remain to be established.

Activity of phospholipase A2 in plasma increases in uremia

We measured phospholipase A2 (PLA2; EC 3.1.1.4) activity in normal and uremic plasma, using [1-14C]oleate-labeled autoclaved Escherichia coli as substrate. Hydrolysis of bacterial phospholipid by crude plasma from both groups was optimal at pH 5.5, was specific for the 2-acyl position of phospholipids, and had an absolute requirement for calcium. Activity was greatest in the presence of added Ca2+, 5 mmol/L, but this increase was inhibited by several divalent cations (Mg2+, Zn2+, Cu2+, Ba2+, Co2+, Pb2+, Fe2+) and by Fe3+. PLA2 activity was also inhibited by heparin at acid and alkaline pH, normal plasma being more sensitive than uremic plasma to this inhibition. Enzyme activity in undiluted plasma was eightfold greater in uremic than in normal plasma. Dilution of plasma by two to fourfold increased the total activity of both normal and uremic plasma. However, the relative differences in total activity between the groups remained constant (eight- to 11-fold). The cause and consequences of the increased PLA2 activity in uremia remain to be established.

Human ehrlichiosis

Ehrlichiosis is one of the latest tick-borne illnesses to be reported in humans. The authors describe two cases of this rickettsial disease that were apparently acquired in Missouri. They discuss diagnosis and treatment.

Determination of oxalate concentration in blood

The methods used for determination of oxalate in blood are reviewed, and the advantages and disadvantages of the two basic approaches--direct methods and in vivo isotope-dilution techniques--are compared. Possible reasons for the previous discrepancies between direct and isotopic methods are discussed, as are the effects of protein binding, sample handling, and storage conditions on oxalate values in plasma. Necessary precautions for obtaining reproducible results are presented. We recommend and critically review several direct methods, and describe the application of a direct method for oxalate determination in some other biological fluids.

Determination of oxalate concentration in blood

The methods used for determination of oxalate in blood are reviewed, and the advantages and disadvantages of the two basic approaches--direct methods and in vivo isotope-dilution techniques--are compared. Possible reasons for the previous discrepancies between direct and isotopic methods are discussed, as are the effects of protein binding, sample handling, and storage conditions on oxalate values in plasma. Necessary precautions for obtaining reproducible results are presented. We recommend and critically review several direct methods, and describe the application of a direct method for oxalate determination in some other biological fluids.

Vermont granite workers' mortality study

A cohort mortality study was carried out in Vermont granite workers who had been employed between the years 1950 and 1982. The cohort included men who had been exposed to high levels of granite dust prior to 1938-1940 (average cutters to 40 million parts/cubic foot), and those employed at dust levels after 1940, which on average were less than 10 million parts/cubic foot. Deaths were coded by a qualified nosologist and standardized mortality ratios were calculated. The results confirm previous studies that show that death rates from silicosis and tuberculosis, the major health threats in the years before 1940, were essentially eliminated after dust controls. However, we found excessive mortality rates from lung cancer in stone shed workers who had been employed prior to 1930, and hence had been exposed to high levels of granite dust. When information was available, 100% of those dying from lung cancer had been smokers.

The effect of an oral leukotriene antagonist L-649,923 on histamine and leukotriene D4-induced bronchoconstriction in normal man

We have studied the effect of prior treatment with an oral leukotriene (LT) antagonist L-649,923, on histamine and LTD4-induced bronchoconstriction in 12 normal male subjects in a double-blind, placebo-controlled, randomized, crossover trial. L-649,923 had no effect on histamine-induced bronchoconstriction but antagonized LTD4-induced bronchoconstriction, causing a mean shift to the right of the dose-response curves of 3.8-fold. This study demonstrates that LT antagonism is possible and safe in man and that LTD4-inhalation challenge testing can be used to detect LT antagonism.

A multicenter trial of immunotherapy with alginate--conjugated grass pollen extract

Conjuvac, a new generation of allergen extracts, has been developed to meet the need for improved characterization, purification, and standardization. Conjuvac consists of a dialyzed, standardized aqueous allergen extract chemically conjugated to a sodium alginate carrier and lyophilized in single-dose vials, thus ensuring stability until reconstituted with sterile water just before each injection. A preliminary study of Conjuvac 2 Grass by Pegelow (1984) involving a small number of patients showed this extract to have potential advantages. Accordingly, a study involving more patients was undertaken: two different maintenance dose levels of Conjuvac 2 Grass were investigated and compared to a pyridine-extracted, alum-precipitated two-grass extract called Allpyral, which in previous double-blind trials has been shown to be effective. The trial, which included 125 patients with hay fever and which extended over 2 years, involved ten allergists from seven European countries. Overall, the Conjuvac high-dose regimen proved slightly superior to Allpyral without any increased incidence of side effects, and all treatments stimulated marked increases in specific IgG levels without raising IgE levels.

Morbidity survey of U.S. oil shale workers employed during 1948-1969

The health status of 325 oil shale workers employed at the Anvil Points, Colorado, demonstration facility from 1948 to 1969 was evaluated. As a comparison population, 323 Utah coal miners frequency matched for age were studied. The prevalence of respiratory symptoms among oil shale workers who smoked were similar to the coal miners who smoked, although nonsmoking oil shale workers had fewer symptoms compared to nonsmoking coal workers. Four cases of skin cancers were found on the oil shale workers and eight cases in the controls. Similar numbers of nevi, telangiectasiae, possible pitch warts, pigment changes (solar/senile lentigo), and papillomata (seborrheic keratoses and skin tags) were seen in both groups, while actinic keratoses were more frequent in the oil shale workers. The prevalence of actinic keratoses was significantly associated with oil shale work after allowing for age, sun exposure, and other exposures. The prevalence of pulmonary cytology metaplasia was associated with years of production work in oil shale among both smokers and exsmokers. More of the oil shale workers had atypical cells in the urine, but the excess was mostly found among exsmokers. Although these workers had short-term and limited oil shale exposure work exposure, we recommend that medical surveillance of oil shale workers consider the skin, respiratory, and urinary systems for special observation.

Pulmonary tuberculosis complicated by haemophagocytic syndrome and rifampicin-induced tubulointerstitial nephritis

The benign, or infection-associated, haemophagocytic syndrome (IAHS) is a rare bone marrow disorder of macrophage cell proliferation diagnosed most commonly in immune compromised patients who develop herpes type viral infections (Risdall et al. 1979). It has also been reported in association with bacterial infections and rarely with mycobacterial infection (Chandra et al. 1975; Mamoharon & Catovsky 1981; Bultmann et al. 1982). Despite being potentially reversible it may produce a life-threatening pancytopenia (Seligman et al. 1972). We report a further case of the haemophagocytic syndrome associated with Mycobacterium tuberculosis in which thrombocytopenia was the predominant feature. There were unusual features in the clinical presentation and the patient's treatment and recovery were subsequently complicated by rifampicin-induced renal failure.

Urinary and plasma oxalate during ingestion of pure ascorbic acid: a re-evaluation

Daily ingestion of 8 g of pure ascorbic acid by 8 normal subjects for 7 days did not, in contrast to previous reports in the literature, significantly alter urinary or plasma oxalate during or after ingestion. When urine with raised ascorbate values was heated at 100 degrees C for 30 min, a significant increase in urinary oxalate concentration was observed. Plasma ascorbate reached a mean value during ingestion of 3.3 mg/100 ml. Urinary citrate excretion significantly decreased during the first 4 days of ascorbic acid ingestion; however, the urinary inhibitory activity of calcium oxalate crystal growth was not significantly altered. Urinary and serum urate as well as urinary calcium and magnesium were unaltered by ingestion of the vitamin supplement.

Sarcoidosis associated with combined immunodeficiency

The association of multiple non-caseating granulomata and a positive Kviem test is normally considered to be indicative of a diagnosis of sarcoidosis. However, although depressed cell-mediated immunity is commonly described, it is extremely rare to find a humoral immune paresis. A patient is reported who had multiple granulomata, depressed cellular and humoral immunity and a positive Kveim test.

Effect of megadoses of ascorbic acid on serum and urinary oxalate

Serum and urinary oxalate was determined in 9 normal subjects, ingesting 8 g of ascorbic acid daily. Serum oxalate levels increased to 310% of control values during supplementation. Plasma ascrobate levels reached a mean value of 3.6 mg% far exceeding the previously reported plateau level of 1.8 mg%. Urinary oxalate gradually increased during ascorbate intake and 7 days post cessation of ascorbate, rose unexpectedly for all subjects into the hyperoxaluric range.

Occupational safety and health implications of increased coal utilization

An area of major concern in considering increased coal production and utilization is the health and safety of increased numbers of workers who mine, process, or utilize coal. Hazards related to mining activities in the past have been especially serious, resulting in many mine related accidental deaths, disabling injuries, and disability and death from chronic lung disease. Underground coal mines are clearly less safe than surface mines. Over one-third of currently employed underground miners experience chronic lung disease. Other stresses include noise and extremes of heat and cold. Newly emphasized technologies of the use of diesel powered mining equipment and the use of longwall mining techniques may be associated with serious health effects. Workers at coal-fired power plants are also potentially at risk of occupational diseases. Occupational safety and health aspects of coal mining are understood well enough today to justify implementing necessary and technically feasible and available control measures to minimize potential problems associated with increased coal production and use in the future. Increased emphasis on safety and health training for inexperienced coal miners expected to enter the work force is clearly needed. The recently enacted Federal Mine Safety and Health Act of 1977 will provide impetus for increased control over hazards in coal mining.

Theophylline disposition in acutely ill hospitalized patients. The effect of smoking, heart failure, severe airway obstruction, and pneumonia

Theophylline disposition (clearance, volume of distribution, and half-life) was measured in 31 normal volunteers and 26 acutely ill patients with airway obstruction within 24 hours of hospital admission and again when intravenous aminophylline was discontinued 2 to 10 days later. Sex, age, race, the diagnosis of asthma, and the diagnosis of chronic bronchitis were not significantly correlated with clearance. Clearance was significantly increased in smokers and significantly decreased in patients with congestive heart failure, pneumonia, and severe bronchial obstruction. The volume of distribution was not correlated with these variables. Within 24 hours of admission, the mean clearance in our patients without congestive heart failure or pneumonia was 44.5 ml per hour per kg of body weight, 40 per cent less than the value on which the widely used 0.9 mg per kg per hour dosage is based. The unexplained interindividual variability of clearance was significantly higher amont patients than control subjects, but intraindividual variability in clearance was not different in these 2 groups after correction for the effects of smoking, congestive heart failure, and so on. Large variability in clearance among patients makes the plasma theophylline concentration resulting from any dosage relatively uncertain. Based on the the results of this study, recommendations are made concerning theophylline dosage computation, and the clinical circumstances calling for determination of plasma theophylline concentrations.

Pleural effusion from malignancy

Pleural effusion from metastatic malignancy can cause major impairment of respiratory function and eventual death. Although cure is not possible, successful palliative treatment allows months to years of productive life, obviating the need for continuous hospitalization and repeated thoracenteses. Successful palliative treatment requires obliteration of the pleural space. Literature survey indicates that a wide variety of medical agents and surgical methods have been used with variable success. Medical methods include instillation of antineoplastic agents, antimicrobial agents, or colloidal radioisotopes into the pleural space; quinacrine and tetracycline are moderately to highly effective agents, but the toxicity of the former is substantial. Bedside talc poudrage with thoracostomy-tube drainage is a safe and highly effective alternative. Pleurectomy is the definitive method of preventing reaccumulation of pleural fluid that results from metastatic malignancy, even when other methods have failed, but thehigh morbidity and mortality of the procedures mandate careful patient selection.

Acid-base induced alterations in glutamine metabolism and ureogenesis in perfused muscle and liver of the rat

The effects of altered acid-base balance on the production of urea and the metabolism of glutamine were investigated in the isolated perfused liver and hindquarter of the rat. In the isolated perfused rat liver, lowering of perfusate pH without altering bicarbonate concentration significantly reduced urea production and increased net glutamine synthesis, although the converse did not obtain. In the isolated perfused rat hindquarter when perfusate pH and bicarbonate were simultaneously reduced glutamine synthesis was significantly increased. The combined hepatic and muscle increase in glutamine synthesis accounted for 89% of the decrease in hepatic urea synthesis under these experimental conditions. These changes in nitrogen metabolism are interpreted in terms of adaptations which offset the initial alterations in hydrogen ion homeostasis.

Generalization and articulation instruction

Three young children were taught correct articulation of an error phoneme on a program administered by their mothers in their homes. During the course of the treatment program each child was periodically brought into the speech clinic where the generalization of correct articulation learned in the home treatment setting could be measured in a series of four settings which differed from the treatment setting in varying degrees. Stimulus words which had not been taught during the home articulation program were also included in generalization testing. The results indicated (1) that correct articulation generalized to a high extent to the nontreatment settings investigated; and (2) that responses to new stimulus words were less adequate than responses to words which had received previous training. The clinical implications of these findings are discussed.

An enzymic method for the spectrophotometric determination of oxalic acid

A simple method is described for the measurement of urinary oxalate. Oxalate decarboxylase is coupled with NAD+ requiring formate dehydrogenase and the result recorded spectrophotometrically. Accurate determination can be carried out either on urine or a citrate extract or urine. Using the citrate extract procedure, the urinary samples can be stored for at least 3 months without any effect on the oxalate content.

The modification of multiple articulation errors based on distinctive feature theory

The effectiveness of articulation remediation procedures based on distinctive feature theory was evaluated through the administration of an articulation program designed for this purpose. Two preschool children with multiple phoneme errors which could be described by a distinctive feature analysis were the subjects. Both children substituted stop phonemes for most continuant phonemes. Each child was individually administered the distinctive feature program which is described in full. Data are presented which indicate the adequacy of the treatment program, the acquisition of correct articulation of the two directly treated target phonemes, and the concurrent improvement of five other nontreated error phonemes. Such across-phoneme generalization was predicted by distinctive feature theory. Certain modifications in the treatment program are suggested and theoretical/empirical questions regarding articulation remediation from a distinctive features viewpoint are discussed.

Synthesis of 5-substituted isophthalic acids and competitive inhibition studies with bovine liver glutamate dehydrogenase

Isophthalic acid, 5-carboxy-, 5-hydroxy-, 5-methoxy-, 5-fluoro-, 5-bromo-, 5-cyano-, and 5-methylisophthalic acid were inhibitors competitive with L-glutamate for bovine liver glutamate dehydrogenase. The extent of inhibition by the derived compounds was not much greater than that obtained with the parent compound, isophthalic acid. A plot of pKi versus pH showed the presence of an ionizable group (pKa 7.4-7.8) at the enzyme active site which interacted with the substitutent at the 5 position of the substituted isophthalates.

Effect of atropine on sputum production

The effect of atropine on sputum production has been studied in patients with asthama, chronic bronchitis, and bronchiectasis in some of whom there was bronchorrhoea. In three patients a reduction in sputum volume was observed after atropine but it would seem that the decrease was mainly due to the inhibitory effect on salivary secretion which facilitates spitting. The one patient treated with long-term oral atropine showed a marked reduction in sputum volume although chemical constituents and viscosity levels remained unchanged, suggesting that in this case atropine had an inhibitory effect on bronchial gland secretion.

Nocturnal and morning asthma. Relationship to plasma corticosteroids and response to cortisol infusion

Nocturnal and early morning breathlessness is a common and important symptom in asthmatic patients. Six patients in whom these symptoms were a major clinical problem have been studied by serial measurements of peak expiratory flow rate (PEFR) and plasma corticosteroids over two 24-hour periods. Although PEFR and plasma corticosteroids are lowest during the night or early morning, preventing the nocturnal fall in plasma corticosteroids by cortisol infusion did not prevent the fall in PEFR in five out of the six patients. The circadian rhythm of corticosteroid secretion does not appear to be the main cause of nocturnal and early morning asthma.

The establishment of fluency with time-out procedures: three case studies

A successful application of time-out procedures is illustrated by three case studies with high school and college-age male stutterers. The method of administering the time-out procedure is described in detail, and typical results are illustrated by data collected from clinical sessions. Modifications of the basic procedure are tested and their results discussed.

Mortality from heart disease in coal miners

A study of 3,726 Appalachian coal miners was undertaken to determine the standard mortality ratio (SMR) for heart disease and to ascertain the effect of smoking, excess weight, and the level of physical activity on deaths due to this cause, SMR's were calculated for all forms of heart disease and also separately for ischemic heart disease. For heart disease as a whole, SMR's of 73 for working and 104 for nonworking miners were obtained. It was found in both working and nonworking miners that obese smokers had the greatest risk of dying of heart disease (SMR's of 142 and 144, respectively). In the nonsupervisory underground work categories of face, transportation, and maintenance, an increase of SMR was observed, with face having the lowest and maintenance workers having the highest SMR. Use of all men from seven Appalachian states vs all US men as a standard population tended to slightly reduce the calculated SMR's.

Glucose utilization and production by the dog kidney in vivo in metabolic acidosis and alkalosis

Using D-[1-(14)C]glucose as a tracer, renal glucose utilization and production was measured in chronic metabolic acidosis and alkalosis in dog kidney in vivo. In six experiments in acidosis, mean total renal glucose production was 4.447+/-1.655 SE mumol/min and glucose utilization was 4.187+/-0.576 SE mumol/min. In five alkalotic experiments it was found that mean total glucose production was 12.227+/-2.026 SE mumol/min and glucose utilization was 18.186+/-2.054 SE mumol/min. Renal glucose utilization and production are therefore significantly higher in alkalosis than in acidosis in vivo. Since glucose production is maximal under conditions when glutamine extraction is minimal (i.e. alkalosis), it is apparent that in alkalosis glutamine is not a major precursor of glucose.