Charles E. Franti

Incidence of traumatic spinal cord lesions

Abstract The incidence of acute spinal cord lesions was studied in the population of 18 Northern California counties for the years 1970 and 1971. Case ascertainment included the complete review of all hospital admissions in these counties as well as the review of all death certificates, autopsy protocols, and records of the State of California Departments of Health (Crippled Childrens Service), Rehabilitation, and Industrial Relations (Workmens Compensation). The average annual incidence rate was 53.4 per million population, and the case fatality rate was 48 per cent. Almost 56 per cent of the spinal cord injuries were attributed to motor vehicle crashes. Incidence rates were three times higher for males 20–24 yr of age and females 25–29 yr of age. The pattern of case fatality rates were not similar for males and females. Age-adjusted incidence rates were highest for black males and lowest for males of Asian origin. Risk of spinal cord injury was highest for divorced or separated persons or those who have never been married. The most frequent type of impairment among persons hospitalized with a spinal cord injury was quadriparesis. Functional impairment was related to the external cause of spinal cord injury. The use of hospitalized persons as a basis for enumeration of spinal cord injuries will result in a gross underestimation of actual incidence. Due to the extremely high costs for medical care of spinal cord injury survivors and the fact that over one-half of all persons who sustained a traumatic lesion to the spinal cord were injured as a result of a motor vehicle crash, any organized program to reduce the incidence of this tragic problem must focus on the reduction of motor vehicle crashes and/or the severity of injuries sustained in them.

Chronic oral infections of cats and their relationship to persistent oral carriage of feline calici-, immunodeficiency, or leukemia viruses

Two hundred and twenty-six cats from the Veterinary Medical Teaching Hospital (VMTH), a cat shelter, and a purebred cattery were tested for chronic feline calicivirus (FCV), feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) infections. Chronic oral carriage of FCV was present in about one-fifth of the cats in each of the groups. FIV infection was not present in the purebred cattery, was moderately prevalent (8%) in the pet population of cats examined at the VMTH for various complaints and was rampant in the cat shelter (21%). Unexpectedly high FeLV infection rates were found in the hospital cat population (28%) and in the purebred cattery (36%), but not in the cat shelter (1.4%). FCV and FeLV infections tended to occur early in life, whereas FIV infections tended to occur in older animals. From 43 to 100% of the cats in these environments had oral cavity disease ranging from mild gingivitis (23-46%), proliferative gingivitis (18-20%), periodontitis (3-32%) and periodontitis with involvement of extra-gingival tissues (7-27%). Cats infected solely with FCV did not have a greater likelihood of oral lesions, or more severe oral disease, than cats that were totally virus free. This was also true for cats infected solely with FeLV, or for cats dually infected with FeLV and FCV. Cats infected solely with FIV appeared to have a greater prevalence of oral cavity infections and their oral cavity disease tended to be more severe than cats without FIV infection. FIV-infected cats that were coinfected with either FCV, or with FCV and FeLV, had the highest prevalence of oral cavity infections and the most severe oral lesions.

INJURY PATTERNS IN MOTORCYCLE COLLISIONS

This report describes the incidence, nature, and severity of trauma for injuried and medically treated motorcyclists in Sacramento County, California in 1970. Using official police reports, hospital admission, and emergency-room medical records, 1,273 persons with a confirmed medically treated motorcycle injury were identified. Since less than 39% of all injured motorcyclists were identified in this study by use of official police reports only, statistics which rely solely on these reports greatly underestimate the frequency of motorcycle collision injuries in the community. The annual injury incidence was 2.0 per 1,000 population, with peak incidence injury rate for male drivers 18 years of age. Slightly more than 4% of all registered motorcycles were involved in an injury-producing collision in a single year. Almost 45% of injured motorcyclists suffered a serious injury, with injuries to the musculoskeletal system in the form of fractures being the most common. The average length of hospital stay was 12 days, and three-fourths of those injured indicated one or more days of disability. Physicians should be alert to the fact that persons injured in motorcycle collisions commonly sustain multiple fractures and other serious injuries.

Survival with an acute spinal-cord injury

Abstract Survival of a cohort of 619 persons who had a spinal-cord injury while resident in one of 18 Northern California counties was determined according to external cause of the injury, level of impairment, age and sex. In addition, causes of death are described and observed and expected numbers of deaths are compared. The case fatality rate was 51.7% over five six years after the spinal-cord injury. Probability of survival was lowest for those injured from motor-vehicle collisions and within this group, the chances of survival were poorest for pedestrians and those involved in multiple-vehicle crashes. Quadriplegics had the lowest survival rates. Survival rates were higher for males than for females. Mortality attributable to the spinalcord lesion was lowest in the young, increasing with age irrespective of type of external cause of the injury, severity of the spinal-cord lesion, or sex. The relative risk of death decreased with age for each of these parameters. Cardiorespiratory complications were the most frequent immediate cause of late deaths for those surviving at least 45 days post-injury.

An epidemiological study of severe osteoarthritis.

A study was made of the relationship between weight, education, use of tobacco and alcohol, participation in athletics and family history of arthritis and severe osteoarthritis of the hip. Estimated relative risk of osteoarthritis was highest for those whose weight was at least 20% or more above ideal, having more than a high school education or with a familial history of arthritis. There was no association between severe osteoarthritis and participation in high school athletics or regular use of alcohol.

Normal Variations of the Position of the Eye in the Orbit

Photoradiographic measurements of projected corneal and nasion pituitary distances in Swedish adults and in white and black adults in the United States were transformed to true measurements. A new photographic method to compute nose-corneal distance was developed and compared to the photoradiographic and Hertel measurements. A new photographic method was developed to record interpupillary distance more accurately than earlier methods. A highly significant difference in eye position between white and black people was found. Variations in normal eye position in the same individual were studied in 39 subjects. Normal eye position was found to vary in an anterior-posterior direction, with an average variation of 1.5 to 2 mm (range, 0-3.7 mm). The interpupillary distance was found to be very stable. A difference of at least 2 mm, and perhaps 3 to 4 mm in exophthalmometric measurements is necessary to detect a pathological difference.

Effect of gonadotropin-releasing hormone on fertility in repeat-breeder California dairy cows.

To assess the potential benefit to fertility from gonadotropin-releasing hormone (GnRH) administration to third service cows managed in typical California dairy systems, 963 cows were enlisted from 14 dairies served by 6 veterinary practices. The cows were randomly assigned to receive either GnRH (100 mug) or placebo at the time of the third artificial insemination. Fertility data were entered onto a proprietary microcomputer program common to all six practices, and collated independently by a third party. For the duration of the trial (1 yr), GnRH and placebo-treated cows had 43.2 and 39.3% conception rates, respectively (P=0.35). When treatments administered in summer months (July, August, September) were excluded, conception rates were 48.1 and 41.0%, respectively (P<0.1). The conception rates of cows treated with GnRH in August tended to be lower than those of placebo-treated cows (95% logarithmic confidence intervals of odds ratio = -1.139, 0.377). Between-herd variation in benefit from GnRH was evident, with two dairies showing no benefit, one dairy showing a negative effect, and four showing a range of effects from lightly beneficial to significantly beneficial. First-lactation cows did not benefit at any time from GnRH treatment. The data suggest that GnRH administered to third-service dairy cows under California conditions may result in increased conception rates in non-summer months, but that other unidentified variables may have important influence on the outcome of such treatment.

Epidemiologic study of physiological effects in usual and volunteer citrus workers from organophosphate pesticide residues at reentry

Biological parameters associated with organophosphate (OP) pesticide exposure were evaluated in a study of citrus harvesters. Changes in these parameters related to environmental residues of cholinesterase (ChE) inhibiting pesticides were studied. Further, it was determined whether usual and volunteer workers differed in their biochemical parameters after exposure to pesticide residues during field operations. Urine metabolite findings for usual farm workers showed that some exposure to OP pesticides had occurred. Too few workers were available during the reentry stage of the field study to evaluate the effect of this exposure on blood ChE. Baseline (nonexposure) acetylcholinesterase (AChE) and plasma cholinesterase (PChE) activities were significantly higher in usual (Mexican American) workers than in volunteer workers (student volunteers). Student volunteers in the test citrus grove showed statistically significant declines in PChE during the exposure period, yet changes in AChE activity, urine metabolites, and residue levels were very small. The implications of these findings are discussed in light of current reentry standards as well as future epidemiologic studies on reentry research.

A seroepidemiological study on bluetongue virus in dairy cattle in the central valley of California.

A seroepidemiological study on bluetongue virus (BTV) infection in California dairy cattle was conducted to estimate the prevalence and distribution by age and season of BTV group-reactive antibodies and to look for possible associations between the presence of antibodies and cattle age or breed and farm. Between December 1985 and March 1987, a sample of cattle was tested at approximately two-month intervals for BTV group-reactive antibodies using an enzyme-linked immunosorbent assay (ELISA). Data taken during the month of December 1986 were used to evaluate possible associations between a positive antibody test and certain intrinsic (age, breed) and extrinsic (farm) factors.Univariate and multivariate statistical analyses using the χ-square test for associations and multiple logistic regression, respectively, were carried out for possible associations between positive antibody tests to BTV and each factor of interest. The strengths of the associations were determined using estimates of the odds ratio.Of the 3774 serum samples tested, 238 (6.3%) were from calves, 1045 (27.6%) were from heifers and 2492 (66.0%) were from cows. Seroprevalence varied from nil in calves on two occasions to over 90% on several occasions in cows. Cows consistently had higher prevalence rates than heifers or calves across all test dates (p<0.05). The seroprevalence of BTV group-reactive antibodies also showed a seasonal fluctuation, with the highest rates occurring during the warmer months of the year. These highest prevalence rates coincided with heavy activity of the known vector of BTV, Culicoides spp. Breed and farm effects were not statistically significant (p>0.05). With the exception of one farm, all cattle were of the Holstein breed, which reduced confidence in assessing any breed effect in this study. Relative estimates of the sensitivity and specificity of BTV ELISA were 87% and 100% respectively, compared to the standard agar gel immunodiffusion (AGID) test.The observations support previous findings of seasonal distribution of BTV antibodies and suggest an age relationship, whereby older cattle are more likely to be positive to BTV group-reactive antibodies than younger cattle.

A cross-sectional study of bluetongue virus and Mycoplasma bovis infections in dairy cattle: II. The association between a positive antibody response and reproduction performance

In a cross-sectional study of bluetongue virus (BTV) and Mycoplasma bovis (M. bovis) infections, a sample of 572 California dairy cows was tested for the presence of antibodies to answer the question: Is it possible to identify and to assess quantitatively the associations between positive antibody test and production? Serum samples collected from these cows during December 1986 were tested for the presence of antibodies to BTV and M. bovis using the enzyme-linked immunosorbent assay (ELISA). Data on milk production were extracted from individual cow sheets of the California Dairy Herd Improvement Association (DHIA) record-keeping system and interfaced with percentage ELISA results for analysis.Univariate and multivariate statistical analyses, using the X2 test for categorical variables or Students t-test for continuous variables and multiple logistic regression respectively, were carried out to evaluate for possible associations between positive antibody tests to each agent and each production variable of interest.Complete data on all variables studied were obtained for 289 (50.5%) cows for M. bovis and 423 (74%) cows for BTV. For cows with complete data on all variables, estimates of the point prevalence of antibodies to BTV and M. bovis were 70.5% and 66.1%, respectively. Results of this study indicated that Guernsey cows were more likely to have a positive BTV test than Holstein cows and that cows in higher lactations were more likely to test positive to BTV ELISA than those in lower lactations (p<0.05). Because all cows except those on one farm were Holstein, our confidence in the effect of breed is limited. The association between lactation number and BTV seropositive test may be an age factor identified earlier in the study. For M. bovis, the results of the analysis indicated that seropositive cows were more likely to produce less milk, on a mature equivalent basis (ORadj=0.96, p=0.034), and that they had less extended 305 day milk production potential (ORadj=0.90, p<0.0001) than seronegative cows.