Effect of time and storage temperature on cholinesterase activity in blood from normal and organophosphorus insecticide-treated horses.

Delays between time of sampling and time of testing are common; therefore, the length of time that blood can be stored at various temperatures was evaluated for effects on cholinesterase activity. Six horses were treated with 16 g of trichlorfon per os, 6 horses were treated with 15 g of dichlorvos per os, and 10 horses were untreated controls. The cholinesterase activity in whole blood from each horse was measured using an adaptation of the Ellman colorimetric method. The blood from each horse was then divided into 3 groups and stored at 5 C (refrigerated), 20 C (room temperature), or 38 C (incubated). Subsequent cholinesterase activities were measured daily and then at weekly intervals. The cholinesterase activities did not significantly increase or were measured daily and then at weekly intervals. The cholinesterase activities did not significantly increase or decrease (P > 0.05) in the blood from the untreated horses until after 1 week for any of the 3 temperature groups. The cholinesterase activities did not significantly increase or decrease (P > 0.05) in the stored blood from the trichlorfon-treated horses for 4 weeks in all 3 temperature groups. The cholinesterase activities significantly increased (P < 0.05) in the stored blood from the dichlorvos-treated horses after 1 week when the blood was refrigerated and by 24 hours when the blood was stored at room temperature or incubated. Therefore, blood from normal or organophosphate-treated horses can be used for cholinesterase evaluation for up to 1 week when stored at 5 C.

Cognitive function and spirometry performance in the elderly.

A total of 65 ambulatory subjects over the age of 65 yr were studied to determine if mild impairment in cognitive function precludes reliable spirometric measures in the aged. Standardized questionnaires were used to obtain information on demographics, cigarette smoking, respiratory symptoms, and physician-diagnosed lung disease. Each subject performed several simple standardized tasks of cognitive function and underwent spirometric testing. A total of 36 women and 29 men participated. The mean age for the group was 74.9 +/- 5.6 yr; most were nonsmokers (never smokers, n = 28; former smokers, n = 29; and current smokers, n = 8). Of the 65 participants, 8 (12.3%) individuals were unable to perform at least three ATS-acceptable FVC maneuvers after suitable demonstration. These subjects were similar to the 57 subjects able to perform three acceptable maneuvers, except for worse scores on both the symbol-digit modalities test (23.3 +/- 3.6 versus 31.6 +/- 10.5, p < 0.001) and the trail-making test, Part B (244.3 +/- 87.1 versus 160.4 +/- 71.8, p < 0.01). Of the 57 subjects able to perform spirometry, 18 (31.6%) failed to meet ATS reproducibility criteria for FEV1, FVC, or both. Cognitive impairment was not associated with the ability to achieve reproducible measures. These results suggest that the vast majority of older subjects can perform reliable spirometry; those elderly unable to perform spirometry may have impairment in cognitive function requiring further evaluation.

Multiresidue screen for organophosphorus insecticides using gel permeation chromatography--silica gel cleanup.

A multiresidue screen for quantitative determination of 43 organophosphorus insecticides in 5 g of plant and animal tissues is described. The organophosphorus insecticides are extracted with methanol-dichloromethane (10 + 90, v/v) and cleaned up using automated gel permeation chromatography with hexane-ethyl acetate (60 + 40) eluant and in-line silica gel minicolumns. Concentrated extracts are analyzed by gas chromatography with flame photometric detection. The method recovers 43 organophosphorus insecticides in the range of 72 to 115%. Analysis of fortified bovine liver (n = 5) shows an average 95.9 +/- 4.8% recovery at the 0.05 micrograms/g level and 93 +/- 3.8% at the 0.5 micrograms/g level. Analysis of fortified bovine rumen content (n = 5) shows an average 98 +/- 4.2% recovery at the 0.1 micrograms/g level and 98.7 +/- 2.8% at the 1 micrograms/g level. Method detection limits ranged from 0.01 to 0.05 micrograms/g for the compounds studied using a nominal 5 gram sample.

Clinical illness associated with a commercial tick and flea product in dogs and cats.

A commercial flea and tick product containing 9.0% fenvalerate for use in dogs and cats was suspected of causing illness. An acute toxicity study was performed in 10 dogs and 10 cats exposed to the product orally (po) and dermally at differing doses. Samples were obtained for DEET and fenvalerate analysis. Oral dosing of dogs and cats produced severe clinical illness at doses as low as 0.66% of a can (7 ounce spray can)/kg body weight. Dermal application of the product resulted in minor clinical abnormalities in dogs. Oral exposure at 0.5% can/kg body weight resulted in severe illness, and dermal application caused severe illness or death in cats at 20% and 40% of a can/kg body weight. The cats receiving 10% of a can/kg body weight dermally became depressed for several hours but recovered uneventfully. Serum DEET concentrations closely paralleled the clinical signs observed in the animals. Serum concentrations of DEET above 20 ppm were considered diagnostic for intoxication. Urine concentrations of DEET above 1 ppm and tissue (liver, bile, and kidney) concentrations of DEET above 10 ppm were supportive of poisoning; values near 100 ppm were diagnostic for fatal poisoning.

Longitudinal study of three views of mandibular third molar eruption in males.

A longitudinal study, using three views simultaneously, was conducted on twenty North American black males to investigate mandibular third molar eruption. Each subject had two third molars present. Forty third molars were studied. Lateral, posteroanterior, and oblique (45 degrees left and right) cephalograms, along with plaster casts, were used. The following observations on the third molars were made; the age at which they can be identified; angulation of the occlusal surface; eruptive path, including the vertical, anteroposterior, and buccolingual positions; and the age of delineation between being unerupted or impacted, including factors related thereto. The Fisher's exact test from the SPSS package and the central tendency were the statistical instruments used to aid in interpreting the data. In some persons the crypt of the developing third molar was seen as early as 7.5 years and the occlusal surface was identified as early as age 8 years, with a mean of 9.75 years. Third molars usually form in the ramus with the distal cusp above the occlusal plane, the occlusal surface of the molar has a great cant facing anteriorly, the tooth descends below the occlusal plane, and appears to upright around 14 to 16 years of age. The impaction of the mandibular third molar is a complex multifactorial mechanism. The wide buccal location of mandibular third molars and the inadequate anteroposterior space between the distal surface of the second molar and the anterior surface of the ramus are important factors in third molar impaction. This study does not support the concept of early prediction of third molar impaction and enucleation of the asymptomatic developing third molars. If possible, the final decision for extraction of asymptomatic mandibular third molars that appear to be impacted should be delayed until after the age of 16 years.

Molar size sequence in American Blacks.

The purpose of this study is to present the data on molar size sequence (MSS) in American Blacks. The results are compared with other studies on American Whites. It is evident from the findings that reasonably high percentage of M2 greater than M1 (where second molars are larger mesiodistally than first molars) exists in both the groups. This suggests that the M2 greater than M1 molar sequence should not be considered as a primitive characteristic, since a high percentage of this sequence is seen in the modern population. The percentage of incidences of M2 greater than M1 in the maxillary arch seems to be significantly higher in American Whites, in both the sexes and as a total group, that in American Blacks. In the case of the mandibular arch, the percentage is significantly higher in American Blacks.

Racial differences in dimensional traits of the human face.

1. Race is difficult to define at best and references to groups are more accurately made on the basis of ethnic groups that are bound by some common bond, such as Swedish Whites, American Whites, etc. 2. The quantifiable differences in the somatic craniofacial region of ethnic groups residing for several generations in the same or similar geographic areas are small. 3. The evidence supports a geographical effect on the most frequently used quantifiable angular measurements of the somatic facial profile of the major racial groups. 4. Cephalofacial morphology is affected by many factors including genetics, function and temperature. 5. There are mean differences in the quantifiable traits of the face of some ethnic groups. The differences in means within ethnic or racial groups are often greater than the differences in means among ethnic or racial groups. 6. The differences in means of traits of the somatic facial skeleton among or between ethnic groups are usually very small with an enormous degree of overlap. 7. The parameters of the face that are closer to the alveolar and dental areas show the greatest differences among ethnic and racial groups.

The mandibular foramen: its anteroposterior position.

This study has been conducted on forty-five Asiatic skulls and sixty-two mixed skulls of black and white Americans to determine the anteroposterior relationship of the mandibular foramen. The mean size of the anterior dimension was greater than the mean size of the posterior dimension of the ramus in all instances. The mandibular foramen was found to be located in the third quadrant anteroposteriorly. The lingula was located just anterior to the mandibular foramen. There was no right- or left-side dominance in the ramus size and position of the mandibular foramen. No appreciable difference was noted in the location of mandibular foramen in the two groups studied.

Mesiodistal crown dimension of the permanent dentition of American Negroes.

A study of the mesiodistal crown dimension was conducted on the teeth of 162 American Negroes, equally divided between males and females. A total of 3,980 teeth were measured. Teeth were measured from the plaster casts by means of Boley gauges. The sample was drawn from a growth study, private practice, and a dental clinic. The mean width of the teeth of males and females was reported. The teeth of males were larger than those of females for each type of tooth in both arches, although they exhibited a similar pattern of tooth size. The maxillary first premolars were larger than the second premolars, while the mandibular second premolars were larger than the first premolars. The first molars were larger than the second molars in both the maxillary and mandibular arches in both sexes. The ratio of the mandibular dentition ot the maxillary dentition was 94 per cent in both sexes. The ratio of the sum of the widths of the canines and incisors of the mandibular dentition to those of the maxillary dentition was 77 per cent. Also, the ratio of the mandibular incisors to the maxillary incisors was 71 per cent in both sexes.