Infant temperament and subject loss due to crying during operant conditioning

Infants who failed to complete a 2-day operant-conditioning task were compared with a stratified random sample of those who did on measures of infant temperament and several demographic characteristics. A discriminant-function analysis revealed that female infants who cried differed from female infants who did not cry on measures of duration of orienting and latency to approach sudden or novel stimuli. Reliable prediction of crying and noncrying could not, however, be made for males. No sex differences emerged in the incidence of crying or in the number of sessions completed. Partially successful females (i.e., those completing 1 of the 2 sessions) could reliably be discriminated from those who cried during the first session on measures of age at testing and maternal ratings of smiling behavior. The results of this study suggest that, as with habituation studies, subject loss in operant-conditioning studies is influenced by individual differences among the infants which may or may not adversely affect external validity.

Limitation of impedance plethysmography in assessing efficacy of dihydroergotamine-heparin prophylaxis of deep vein thrombosis

The sensitivity of impedance plethysmography (IPG) for diagnosing deep vein thrombosis was evaluated in the presence of dihydroergotamine, an agent with significant venoconstrictor activity. In a prospective, randomized, controlled clinical trial, 105 patients undergoing total hip replacement surgery were investigated to evaluate the thromboprophylactic efficacy of DHE-Heparin using IPG and 125I-Fibrinogen Leg Scanning to monitor the incidence of DVT. Retrospective analysis of the IPG data indicated that DHE-Heparin impaired the sensitivity of impedance plethysmography by decreasing venous capacitance and venous outflow. Although the patient sample size was relatively small, the results showed trends which suggested that the utility of impedance plethysmography for diagnosing DVT was limited in the presence of a vasoactive agent. Alternate noninvasive diagnostic methods may need to be considered in select patients receiving concomitant medications possessing venoconstrictor activity.

Comparison of the metabolic activation of 7, 12-dimethylbenz(a)anthracene by a human hepatoma cell line (HepG2) and low passage hamster embryo cells

Under similar conditions of cell-mediated mutagenesis, secondary hamster embryo (HE) cells were much more effective than were cells of the human hepatoma cell line, HepG2 , in activating 7, 12-dimethylbenz(a)anthracene (DMBA) to metabolites mutagenic for V79 Chinese hamster cells. At the same dose of DMBA (0.1 microgram/ml), mutation induction (6-thioguanine resistance) with HE cells as activators was about ten times greater than with HepG2 cells as activators. Both cell types rapidly metabolized DMBA. HepG2 cells converted DMBA primarily to water-soluble derivatives that were neither sulfates nor glucuronides, whereas HE cells converted DMBA to a variety of organic solvent-soluble and water-soluble metabolites. The major water-soluble metabolites produced by HE cells were phenol-glucuronides. In HepG2 cells, binding of DMBA to DNA reached a maximum value of 12.1 pmol/mg DNA at 12 hr, whereas in HE cells, binding reached a peak value of 180.7 pmol/mg DNA at 24 hr. Despite this difference in total binding between the two cell types, the pattern of DNA adducts formed was nearly identical. The results indicate that the marked difference in the ability of HepG2 and HE cells to activate DMBA in cell-mediated mutation assays is not due to a lower metabolizing capacity of HepG2 cells for DMBA. Rather, significant differences in the metabolic pathways used by the two cell types lead to a marked reduction in DNA-binding metabolites in one cell type ( HepG2 ) compared to the other (HE).

Replicated evidence on the construct validity of the SCAG (Sandoz Clinical Assessment-Geriatric) scale

Factor analysis procedures, applied to a data bank of 1165 senile patients from 21 double-blind studies, yielded 5 factors: cognitive dysfunction (4 items), interpersonal relationships (4 items), apathy (4 items), affect (3 items) and somatic function (3 items). A retrospective review of the 1165 case histories revealed that patients fell into three distinct diagnostic classes: (a) patients whose symptoms of dementia were likely associated with multiple infarcts; (b) patients with other medical disorders such as metabolic imbalances, pulmonary diseases, etc. which may have induced dementia-like symptoms; and (c) primary degenerative dementia for patients with no evidence of other intervening causes. Factor analysis applied independently to the SCAG data of each of the three groups produced similar factor constructs, thereby suggesting that results reported with this instrument are valid across different geriatric diagnostic categories.

Benzo(a)pyrene and 7,12-dimethylbenz(a)anthracene metabolism and DNA adduct formation in primary cultures of hamster epidermal cells

Primary cultures of hamster epidermal cells exposed to hydrocarbon, 1 microgram/ml, rapidly metabolized [3H]benzo(a)pyrene and [14C]7,12-dimethylbenz(a)anthracene to ethyl acetate:acetone- and water-soluble metabolites. By 24 hr, only 13.6% of the organic solvent-soluble radioactivity recovered in the medium was unchanged [3H]benzo(a)pyrene, and only 5.9% was unchanged [14C]7,12-dimethylbenz(a)anthracene. With both hydrocarbons, the major water-soluble metabolites found extracellularly were conjugated with glucuronic acid; these were primarily phenolic derivatives. Metabolites cochromatographing with 7,8-dihydro-7,8-dihydroxybenzo(a)pyrene or trans-3,4-dihydro-3,4-dihydroxy-7,12-dimethylbenz(a)anthracene were not detectable in high-pressure liquid chromatographic profiles of organic solvent-soluble intracellular and extracellular metabolites. However, analysis of [3H]benzo(a)pyrene: and [3H]7,12-dimethylbenz(a)anthracene: DNA adducts indicated that these putative proximate carcinogenic metabolites were formed in these cells and subsequently metabolized to DNA-binding products. The results suggest that metabolic incompetence may not be an explanation for the relative resistance of the hamster to epidermal carcinogenesis by polycyclic hydrocarbons.

Benzo(a)pyrene metabolism in primary cultures of mouse epidermal cells and untransformed and transformed epidermal cell lines

The metabolism of [3H]benzo(a)pyrene [B(a)P] by cultures of primary mouse epidermal cells and untransformed and transformed epidermal cell lines was investigated. All three cell types effectively metabolized [3H]B(a)P. The major organic solvent-extractable metabolites found intracellularly in primary cultures were trans-7,8-dihydro-7,8-dihydroxybenzo(a)pyrene and 3-hydroxybenzo(a)pyrene, although quantities of 9-hydroxybenzo(a)pyrene, trans-9,10-dihydro-9,10-dihydroxybenzo(a)pyrene, and quinones also were present. The major organic solvent-soluble metabolites found in the extracellular medium were trans-9,10-dihydro-9,10-dihydroxybenzo(a)pyrene and trans-7,8-dihydro-7,8-dihydroxybenzo(a)pyrene, with smaller quantities of unconjugated phenols and quinones. The major water-soluble metabolites found in the extracellular medium were conjugated with glucuronic acid [primarily 3-hydroxybenzo(a)pyrene and several quinones]. No sulfate conjugates of [3H]B(a)P metabolites were detected. [3H]B(a)P metabolism was similar in cultures of untransformed and transformed epidermal cell lines but differed from the primary cultures. The major intracellular and extracellular organic solvent-soluble metabolites were diols. Little or no unconjugated phenols were detected. Both the untransformed and transformed epidermal cell lines converted [3H]B(a)P to water-soluble metabolites, primarily glucuronide conjugates. In contrast to the primary cells, a major pathway of trans-7,8-dihydro-7,8-dihydroxybenzo(a)pyrene metabolism in the untransformed and transformed cell lines was a glucuronide conjugate. Primary mouse epidermal cells provide an important model system for studying factors affecting the activation and detoxification of hydrocarbon carcinogens.

Tumor-initiating activity of 4-fluoro-7,12-dimethylbenz[a]anthracene and 1,2,3,4-tetrahydro-7,12-dimethylbenz[a]anthracene in female SENCAR mice

We have determined the skin tumor-initiating activity in SENCAR mice of two A-ring derivatives of 7,12-dimethylbenz[a]anthracene (DMBA). 4-Fluoro-7,12-dimethylbenz[a]anthracene at a dose of 200 nmol per mouse exhibited weak activity, producing 0.6 papillopmas per mouse; doses of 10 and 20 nmol per mouse had no activity. A derivative of DMBA with the A-ring reduced, 1,2,3,4-tetrahydro-7,12-dimethylbenz[a]anthracene (1,2,3,4,-H-DMBA), had substantial tumor-initiating activity when compared with the parent hydrocarbon. In one experiment, doses of 10 and 100 nmol per mouse gave rise to 1.6 and 9.5 papillomas per mouse, respectively; similar results were obtained in 3 additional experiments. Although the tumor-initiating activity of 1,2,3,4,-H4-DMBA was approximately one-tenth that of DMBA, this derivative was slightly (17%) more active than benzo[a]pyrene. 1,2,3,4-H4-DMBA was tested for the ability to induce mutations to 6-thioguanine-resistance in Chinese hamster V79 cells. In the absence of feeder cells capable of metabolizing polycyclic hydrocarbons, it was not mutagenic. However, in a cell-mediated mutation assay with secondary hamster embryo cells as activators, this derivative produced mutations in a dose-dependent manner and was approximately one-tenth as active as DMBA. These results indicate that metabolism of DMBA at positions 1-, 3-, 2- and 4- is important for biological activity and that for certain derivatives (i.e., 1,2,3,4-H4-DMBA), alternate pathways of metabolic activation may also be important.

A DL-DOPA drop test for the identification of Cryptococcus neoformans

A simple melanin assay using DL.DOPA as the substrate was developed to aid in the identification of Cryptococcus neoformans. The DL-DOPA drop test was simple and efficient. The best results (100% of the C. neoformans isolates were positive) occurred when C. neoformans was grown for two days at room temperature on Sabouraud agar modified. One to three loopfuls of yeast cells were then transferred to a starvation medium for 18-24 hours. Two of three drops of 0.3% DL-DOPA solution was applied to the transferred yeast cells. Only C. neoformans produced a brown or blackgrey pigment within 24 hrs, with 85% of the isolates becoming brown or black-grey within thirty minutes.

Esculin-based medium for isolation and identification of Cryptococcus neoformans

A simple medium was developed, using esculin as the substrate, for the isolation and identification of Cryptococcus neoformans. C. neoformans produced a brown-black pigment on the medium; all other yeasts produced no pigment or were light yellow. Esculin is beta-glucose-6,7-dihydroxycoumarin. C. neoformans produced pigment because the 6,7-dihydroxycoumarin component of the esculin molecule was converted to a melanin-like pigment. We think the reaction was similar to the conversion of diphenols, aminophenols, and diaminobenzenes to melanin. Laboratory studies with isolates of C. neoformans, C. albidus, C. luteolus, and C. terreus and representatives of the genera Candida, Torulopsis, Geotrichum, and Rhodotorula, plus environmental field studies, demonstrated that over 95% of C. neoformans isolates were correctly identified, whereas all other fungi were excluded. Esculin agar was a sensitive, specific medium for the isolation and identification of C. neoformans. It was inexpensive and had a long storage life.

Isodense acute subdural hematoma

An unusual isodense acute subdural hematoma is reported. Its causes may have included dilution with cerebrospinal fluid and a local or disseminated coagulopathy. Detection of such lesions requires a high incidence of suspicion based on subtle abnormalities found on computed tomography and the use of enhancement, particularly with the aid of advanced scanners. When a significant shift of the midline is seen, other alternatives would be angiography or placement of an exploratory burr hole on the "swollen" side.

Rapid biochemical characterization of Haemophilus species by using the micro-ID

Biotyping of Haemophilus influenzae into five type and H. parainfluenzae into three types based on indole production, ornithine decarboxylase, and urease has been reported (M. Kilian, Acta Pathol. Microbiol. Scand. Sect. B 82:835--842, 1976). A commercially available test system designed for the 4-h identification of Enterobacteriaceae. Micro-ID, proved efficacious for the rapid biotyping of these two Haemophilus species. The nitrate reductase, indole production, ornithine decarboxylase, urease, and o-nitrophenyl-beta-D-galactopyranoside hydrolysis tests in Micro-ID correlated over 99% with conventional methodology. By utilizing the indole and o-nitrophenyl-beta-D-galactopyranoside tests it was possible, with 261 of 272 (96.1%) isolates, to distinguish H. influenzae from H. parainfluenzae. Cerebrospinal fluid isolates were over 90% H. influenzae biotype I, and conjunctival isolates were approximately 70% biotype II. Type b H. influenzae were predominantly biotypes I and II; these type b isolates were also overwhelmingly indole producers. Although over 90% of biotypes I and II have been reported to produce beta-lactamase, this was not confirmed by the small number of beta-lactamase producers encountered here. The 4-h Micro-ID should prove a useful mechanism, amenable to the routine clinical laboratory, for the further exploration of the association of Haemophilus with the site of isolation, antigenicity, and antibiotic resistance.

Rapid identification of Enterobacteriaceae from blood cultures with the Micro-ID system

Micro-ID is a new test system designed to identify members of the family Enterobacteriaceae in 4 h. It consists of 15 biochemical tests on reagent-impregnated paper disks; each test is in its own compartment in a molded plastic tray. Based on the pattern of positive and negative biochemical reactions, a five-digit octal code number is calculated. A computer-generated identification manual accompanies the product, and for each octal code listed there is a numerical value that represents the unknown isolate's degree of fit to a typical organism (LFR), a second numerical value that represents its separation from other organisms (PNOR), and a verbal description of the quality of identification. Only one reagent is added to the system. Manufacturer's directions were modified in this laboratory to allow identification from a turbid blood culture bottle within 4 h. Based on 330 routine clinical cultures tested, there was a 96.1% agreement with conventional identification to the genus and species level: 1.2% yielded first two choices possible, with one being the correct choice; 1.2% provided a correct genus, but no species identification; and 1.5% produced an incorrect identification. The Micro-ID is an accurate, facile system for the rapid identification of Enterobacteriaceae from blood cultures.

Quality control of the latex-fixation test

Standardization of the latex-fixation test for the detection of rheumatoid factor may be achieved by the preparation of a standard reference serum. A number of guidelines for the quality control of precision and sensitivity of the test are suggested. In the use of dilution procedures, a 0.1 log10 or a 0.05 log10 difference between tubes is employed. The end point is defined and titer expressed in terms of a final dilution represented by the amount of antigen-antibody added. For statistical purposes all serologic data are geometrically expressed. Commercial kits may be standardized in terms of minimum detectable units and normalized for titer and unit values to enable laboratories to compare results.

Performance of latex-fixation kits used for serologic diagnosis of rheumatoid factor in rheumatoid arthritis sera

Ten latex-fixation kits (both slide and tube) were evaluated by use of a reference serum containing 250 IU of rheumatoid factor (Communicable Disease Center). All tests were performed with serial dilution of serum; adjacent tubes differed by a factor of 0.10 log10. Geometric titers, means, standard deviations, and variance analysis were used to evaluate commercial kits. Three levels of variance were applied: (1) 0.18 or less for intralaboratory variation when the same serum is tested with the same kit; (2) 0.18-0.35 when various lots or batches of the same serum were used; (3) 1.0 or less when various commercial kits were tested with the same serum. The sensitivity of each commercial kit was determined by assigning to it a value (the minimum detectable unit) arrived at by dividing the number of units in the standard by the titer obtained. The technic presented could be applicable to other serologic tests, and thus provide a general method for their standardization and quality control.

Clinical evaluation of the MICRO-ID, API 20E, and conventional media systems for identification of Enterobacteriacea

MICRO-ID (General Diagnostics, Morris Plains, N.J.) is a new kit system designed for the identification of Enterobacteriaceae in 4 h. It consists of 15 biochemical tests of paper disks. Each test is in its own compartment in a molded plastic tray. Only one reagent need be added to the system (2 drops of 20% KOH, which is added to the Voges-Proskauer test). Based on the pattern of positive and negative biochemical test results, a five-digit octal code number is calculated. An identification is derived from a computer-generated identification manual. A study was conducted to compare three systems-the MICRO-ID 4-h and the API 20E (Analytab Products Inc., Plainview, N.Y.) 18- to 24-h systems and a conventional media system-to measure the ability of each to identify members of the family Enterobacteriaceae. Comparison tables, rather than simple percentage agreement tables, were generated to define the particular strengths and weaknesses of each system and allow the laboratory to best use the data. The MICRO-ID compared quite favorably with conventional media. MICRO-ID yielded incorrect identifications with 1.5% of the isolates tested (API 20E, 4.7% misidentification rate). Half the MICRO-ID misidentifications occurred when the system identified a Citrobacter diversus as a lysine-negative Escherichia coli; all gave one octal number. A direct comparison of the MICRO-ID and API 20E was of limited value because percentage agreements were merely the sums of the errors of each. The ease of inoculation, the requirement for the addition of only one reagent, and the 4-h capability make the MICRO-ID system an extremely attractive development in the field of bacterial identification.

Three-wavelength light transmission technique to measure smoke particle size and concentration

This paper describes an optical technique and instrumentation for measuring the average particle size and mass concentration of smoke. Transmission through the smoke at three wavelengths (0.45 microm, 0.63 microm, and 1.00 microm) is measured using a white light source and a compact, three-wavelength detector assembly. Sizes and concentrations are then calculated from the transmission data using Mie theory. Graphs of the calculated Mie extinction coefficients are presented for several complex refractive indices. This three-wavelength optical technique was used to study smoke from a wood-tunnel fire, and the results are compared to those of other sizing techniques.

Clobazam versus placebo for anxiety and tension in psychoneurotic outpatients. A multicenter collaborative study

Clobazam, a 1,5-benzodiazepine, was compared with placebo in 190 psychoneurotic outpatients with prominent symptoms of anxiety and tension of at least two weeks of duration. The design was one of double-blind parallel groups treated for one week. Clobazam subjects began on 40 mg daily in divided dosage, which was increased to 80 mg daily be day 3 if the drug was well tolerated. Two patients receiving clobazam had laboratory chemistry abnormalities which were possibly drug related. Adverse effects occurred more frequently in the clobazam group and were typical of those of marketed benzodiazepines. This study indicates that clobazam is an effective anxiolytic agent demonstrating its clinical effects during the first week of treatment.

Esculin hydrolysis by Enterobacteriaceae

Literature reports disagree concerning esculin hydrolysis in the family Enterobacteriaceae. A total of 2,490 strains of the family were investigated for esculin hydrolysis by two methods, the esculin spot test and the PathoTec incubation strip, which measures constitutive enzyme, and five growth-supporting methods, which determine both constitutive and inducible enzymes. The five growth-supporting media studied were: Vaughn-Levine, the standard esculin hydrolysis medium (P. R. Edwards and W. H. Ewing, Identification of Enterobacteriaceae, 3rd ed., 1972); Vaughn-Levine without iron; Vaughn-Levine without Andrade's indicator; and bile-esculin medium. Growth media were incubated at 35 degrees C and checked every 24 h for 120 h. On growth media, 0.3% of Escherichia coli were positive in 24 h, 34% in 48 h, and 61% in 120 h. No strains were positive on the "nongrowth" tests. It appeared that the esculin hydrolysis enzyme(s) of E. coli was inducible rather than constitutive. All esculin hydrolyzers, which yielded positive tests on "constitutive tests" and 24-h tests, were limited to the genera Klebsiella, Enterobacter, and Serratia and species of Proteus vulgaris, Proteus rettgeri, and Citrobacter diversus. When used with standardized inoculum size and incubation time, the esculin hydrolysis test is very useful for differentiation within the family Enterobacteriaceae.

The use of bile - esculin agar for the taxonomic classification of the family Enterobacteriaceae

Bile-esculin medium has been used for many years for the presumptive identification of group D Streptococcus. The test is based on the ability of a bacterium to grow in the presence of 40% bile and produce esculinase. 2935 strains of Enterobacteriaceae were inoculated onto bile-esculin agar slants and incubated at 35 C. Esculin hydrolysis was determined after 24 and 48 hours. At 24 hours of incubation esculin hydrolysis was limited to the genera Klebsiella, Enterobacter, Serratia, and the species P. vulgaris, P. rettgeri, and C. diversus. Not all strains of these species were positive, however. All other members of the family were negative. At 48 hours of incubation 37% of E. coli gave a positive reaction; all other Enterobacteriaceae which were negative at 24 hours remained negative. Esculin hydrolysis is a valuable test for the taxonomic classification of the family Enterobacteriaceae.