Characterization of a spontaneous disease of white leghorn chickens resembling progressive systemic sclerosis (scleroderma).

University of California, Davis (UCD) line 200 White Leghorn Chickens spontaneously develop a syndrome that has many analogous features to human progressive systemic sclerosis. This syndrome is characterized by progressive involution of comb, dermal fibrosis, and distal polyarthritis. These three features occur within 6 wk after hatching, and are accompanied by a 40% mortality as a result of vaso-occlusive disease, with development of secondary infection of peripheral gangrenous lesions. Birds that survive greater than 2 mo after hatching progressively develop fibrosis of the esophagous and mononuclear infiltration of heart and kidney, with prominent occlusion of small and medium sized blood vessels. In addition, line 200 chickens develop rheumatoid factors, antinuclear antibodies, and antibodies to collagen, but do not have antibodies to thymocytes, DNA, or extractable nuclear antigens. Moreover, antinuclear antibodies when studied using HEp-2 cells as substrate demonstrate predominantly a speckled pattern. This syndrome of line 200 chickens is not detectable in F1 crosses to several UCD inbred lines. F1 X parental line BC1 backcrosses have an approximately 50% incidence of disease, suggesting that this syndrome is inherited as autosomal recessive. However, only 4% of F2 generation birds show abnormal symptoms, suggesting the presence of modifying genes. There is no appearance of IgG deposition, as determined by immunofluorescence, in either skin, blood vessels, esophagus, or heart. However, approximately 20% of chickens have a glomerulonephritis; this feature appears to be a terminal event and does not appear clinically significant. Although this syndrome of line 200 chickens has several features that are in sharp distinction to human scleroderma, the presence of common immunologic and pathologic denominators suggest that this spontaneous disease may be an appropriate model to develop a better understanding of autoimmune connective tissue diseases.

Immunobiology of heterotransplanted human tumors in nude mice.

The immunobiology of heterotransplanted human tumors was investigated following transplantation into nude mice of human bronchogenic, colon, rectal, ovarian, gastric, endometrial, vaginal, bladder, renal, esophageal, embryonic cell, pancreatic, and breast carcinoma, as well as fibrosarcoma, rhabdomyosarcoma, malignant melanoma, astrocytoma, Wilm's tumor, endometrial hyperplasia, and hydatidiform mole. Several of these tumors were passaged up to 15 generations. During these passages no changes in latency period for tumor development or in histology were noted. There were significant differences between several tumors in the minimum number of cells required for successful transplantation; such differences were independent of the basic biologic aggressiveness of the individual tumors. Nude mice that received transplants of fibrosarcoma and endometrial carcinoma had increased serum IgM and numbers of spleen cells and complement receptor lymphocytes. No such changes were noted for mice that received transplants of malignant melanoma, In contrast, there were no apparent differences in the responses of nude mice, who were given transplants of human tumors, to be T-cell mitogens concanavalin A or phytohemagglutinin or in the number of theta-bearing spleen cells. The success rate for transplantation was significantly improved when explants, rather than single-cell suspensions, were performed. Tumors transplanted to nude mice derived from strictly homozygous matings behaved like tumors transplanted to mice born of heterozygous mothers. Finally, despite the dramatic size of subcutaneous tumor nodules, there were no examples of invasion or distant metastases.

Enhancement of heterotransplanted human tumor graft survival in nude mice treated with antilymphocyte serum and in congenitally athymic-asplenic (Lasat) mice.

The latency period, success rate, and minimal cell inoculum size required for transplantation of continuously passaged human tumor lines into congenitally athymic (nude) mice, antilymphocyte serum (ALS)-treated congenitally athymic (nude) mice, and congenitally athymic-asplenic (lasat) mice were compared. The 11 tumor lines studied included examples of breast adenocarcinoma, transitional cell carcinoma, osteosarcoma, fibrosarcoma, Hodgkin's disease, malignant melanoma, and rhabdomyosarcoma. Of these 11 tumor lines, 3 were successfully transplanted into nude mice, compared to 5 of 10 tumor lines in ALS-treated nude mice and 9 of 11 lines in lasat mice. Moreover, the latency period was shorter and the minimal cell inoculum size was lower for lasat mice than for either nude or ALS-treated nude mice. Despite this enhancement of heterotransplantation into lasat mice and despite the growth of large local masses, no evidence of distant metastases was found.

Thrombotic complications of umbilical artery catheters: A clinical and radiographic study.

Catheterization of the aorta via the umbilical artery provides a convenient route for monitoring arterial blood pressure, for obtaining blood specimens for measurement of blood gas tensions and chemistries, and for the infusion of fluids and pharmacologic preparations in sick newborn infants. Use of this technique may be accompanied by a number of complications of which thrombotic phenomena are the most common. Twenty-three of 98 (24%) newborn infants undergoing umbilical artery catheterization were found to have thrombotic complication determined by aortography. No correlation was present between the duration of time that the umbilical artery catheters were in place and the occurrence of thrombotic complications. From paired aortographic or aortographic and autopsy studies in 24 patients, it was concluded that if a thrombotic complication did not occur early, none was likely to occur subsequently. One patient was considered to have died as a direct result of a thrombotic complication. Aortography is a safe, simple, and reliable technique for the early detection of thrombotic complications of umbilical artery catheters. Umbilical artery catheterization is not without risk and careful selection of patients for this procedure is indicated.

Effects of laser irradiation on human thrombus: demonstration of a linear dissolution-dose relation between clot length and energy density.

Because vascular thrombosis often accompanies arteriosclerotic disease in occluding blood vessels, the dissolution properties of laser irradiation were investigated and the energies needed to penetrate different lengths of thrombus were quantitated. Spectrophotometric studies show that the blood clot due to the presence of hemoglobin is well absorbed by argon laser energies, which emit blue-green wavelengths between 454 and 514 nm. Thus, laser energies transmitted directly from an argon-ion source produced vaporization and penetration of human thrombus in a linear dose-response fashion; the longer the thrombus, the greater the power intensity or time exposure necessary to penetrate the clot.

Acute and chronic complications of laser angioplasty: vascular wall damage and formation of aneurysms in the atherosclerotic rabbit.

Acute and chronic vascular responses to laser exposure in atherosclerotic rabbits were studied. In 7 rabbits fed an atherogenic diet for 3 to 5 months before the study to induce aortic atherosclerosis, a flexible quartz fiber, 400 micron core diameter, attached to an argon ion laser was passed anterogradely or retrogradely to the atherosclerotic ascending aorta. The laser was turned on using power intensities of 1 to 2 W for 3 seconds. After laser treatment, the aortas were studied acutely in 3 rabbits and chronically in 4 rabbits after recovery for 1 to 14 days. In 2 rabbits studied acutely, the argon laser produced a vaporized crater within the atherosclerotic plaque at the endothelial surface; however, in 1 there was also vascular damage extending deep into the medial layer. In addition, aortic aneurysm with muscular wall damage occurred in 2 of the 4 animals studied chronically. Thus, vascular complications may arise when catheter laser angioplasty is randomly applied without visualizing specific plaque targets or without using safe dose increments of power intensities and durations of exposure. This study suggests caution in the clinical use of intensive phototherapy to cardiovascular lesions and stresses the need for further understanding of laser vascular consequences before application of laser angioplasty in patients.

Nosocomial tuberculosis: an outbreak of a strain resistant to seven drugs.

OBJECTIVE: To evaluate nosocomial transmission of multidrug-resistant (MDR) tuberculosis (TB). DESIGN: Outbreak investigation: review of infection control practices and skin test results of healthcare workers (HCWs); medical records of hospitalized TB patients and mycobacteriology reports; submission of specimens for restriction fragment length polymorphism (RFLP) typing; and an assessment of the air-handling system. SETTING: A teaching hospital in upstate New York. RESULTS: Skin-test conversions occurred among 46 (6.6%) of 696 HCWs tested from August through October 1991. Rates were highest on two units (29% and 20%); HCWs primarily assigned to these units had a higher risk for conversion compared with HCWs tested following previous incidents of exposure to TB (relative risk [RR] = 53.4, 95% confidence interval [CI95] = 6.9 to 411.1; and RR = 37.4, CI95 = 5.0 to 277.3, respectively). The likely source patient was the only TB patient hospitalized on both units during the probable exposure period. This patient appeared clinically infectious, was associated with a higher risk of conversion among HCWs providing direct care (RR = 2.37; CI95 = 1.05 to 5.34), and was a prison inmate with TB resistant to seven antituberculosis agents. The MDR-TB strain isolated from this patient also was isolated from other inmate and noninmate patients, and a prison correctional officer exposed in the hospital. Mycobacterium tuberculosis isolates from all of these patients had matching RFLP patterns. Infection control practices closely followed established guidelines; however, several rooms housing TB patients had marginal negative pressure with variable numbers of air changes per hour, and directional airflow was disrupted easily. CONCLUSIONS: These data strongly suggest nosocomial transmission of MDR-TB to HCWs, patients, and a prison correctional officer working in the hospital. Factors contributing to transmission apparently included prolonged infectiousness of the likely source patient and inadequate environmental controls. Continued urgent attention to TB infection control is needed.

Apparent absence of Sarcocystis and low prevalence of Trichinella in artificially digested diaphragm muscle removed during post-mortem examination at a Sacramento (California) medical center.

Diaphragm samples taken from 297 humans at autopsy over a 20-mo period were artificially digested and the digestate was examined for Sarcosystis and Trichinella. No infection with Sarcocystis was found while three infections with Trichinella were discovered.

Recommended data elements for firearm-related injury surveillance.

During 1994, the Centers for Disease Control and Prevention (CDC) funded seven states to develop and evaluate surveillance systems for firearm-related injuries. In addition, New York City and California had related experience with firearm-related injury surveillance. At the time these nine jurisdictions began developing their surveillance systems, no standardized definitions or recommendations were available about the best methods or procedures of collecting data or suggested data elements of a firearm-related injury surveillance system. The nine jurisdictions and CDC developed a list of recommended data elements (RDEs) for fatal and nonfatal firearm-related injuries. We describe the process used to develop the RDEs, the 21 data elements suggested by the funded projects, the data sources that may be able to provide those data elements, and an indication of which sources may be most useful. We encourage all developing surveillance systems to strive to include these data elements, although some of the elements will be more easily attainable for fatal injury events than nonfatal ones, and no single data source will be able to provide all the desired information about both morbidity and mortality from firearm-related injuries. The RDEs capitalize on the preliminary experiences of the small group of jurisdictions, but they need to be pilot tested and revised as we collect more information about how well these elements capture the desired information and whether the information obtained is useful.

The prevention of youth violence. The rationale for and characteristics of four evaluation projects.

In response to the magnitude of violence in the United States, a number of violence-prevention programs have been implemented throughout the country. However, relatively few have been rigorously evaluated for effectiveness. To encourage development and evaluation of violence-prevention interventions that focus on young children and their families, the Centers for Disease Control and Prevention (CDC) provided funding to four projects in 1996. This paper briefly describes the rationale for funding these projects, which is based on our understanding of the development of aggressive and violent behavior and on the literature regarding promising approaches to prevent problem behavior in this age group. We provide an overview of the four specific projects funded by the CDC as well as a short discussion of some of the many challenges encountered during their implementation.

Oklahoma Firearm-Related Injury Surveillance.

CONTEXT: The magnitude of firearm-related deaths is known, but few studies have evaluated the magnitude and epidemiology of nonfatal firearm-related injuries. The circumstances resulting in fatal versus nonfatal injury are likely very different. No single data source provides complete details on nonfatal shootings. OBJECTIVE: To establish a surveillance system to define the epidemiology of fatal and nonfatal firearm-related injuries. DESIGN: Data were collected on fatal and nonfatal firearm-related injuries that occurred in 1995. SETTING: State of Oklahoma. PARTICIPANTS: Medical Examiner, Vital Statistics, hospital emergency and medical records departments, police departments, newspaper clipping service. MAIN OUTCOME MEASURES: Incidence rate of firearm-related injuries; case-fatality rate; demographic, medical, and epidemiologic data; sensitivity of each reporting source; completeness of reporting. RESULTS: The incidence rate of firearm-related injuries was 45.5 per 100,000 population. The case fatality rate was 35%. Injury rates were highest among adolescents, young adults, males, and African Americans. The Medical Examiner and Vital Statistics reported 87% and 98% of fatal cases, respectively. Passive surveillance of hospital emergency departments identified 72% of patients seeking hospital treatment. Among inpatients, 81% were identified by medical records departments. Newspaper clippings were obtained for 31% of cases. Information on the victim-perpetrator relationship and the type of firearm was available for 79% and 80% of cases, respectively. CONCLUSIONS: Statewide surveillance of firearm-related injuries using multiple data sources is possible and provides a picture of the overall firearm-related injury problem. Strategies to enhance computer linkages of medical and police data should be pursued to maximize the sensitivity of reporting and minimize the costs of surveillance.

Trends in fatal firearm-related injuries, United States, 1962-1993.

OBJECTIVE: Our objective was to review historical trends in U.S. fatal firearm-related injuries for the years 1962-1993. METHODS: Using mortality data from the National Center for Health Statistics and population estimates projected from census data, we calculated national age-adjusted mortality rates and examined trends over the 32-year period. Data were also examined by type of firearm-related death (unintentional, suicide, homicide, legal intervention, and undetermined intention), race, gender, and age group. RESULTS: During the 32-year period, the total number of firearm-related deaths increased by 137%, from 16,720 in 1962 to 39,595 in 1993. Suicide and homicide were responsible for most firearm fatalities. Rates for both firearm suicides and firearm homicides increased over time, while rates for unintentional, legal intervention, and undetermined intention decreased. The highest rates and widest variation in total firearm-related mortality occurred among African-American men (35.2/100,000 to 84.5/100,000). Persons 15-19, 20-24, and > or = 75 years of age experienced the largest changes in rates during recent years; total firearm mortality was higher for the younger age groups (15-19, 20-24) during 1990 through 1993 than any other time during the 32-year period. CONCLUSIONS: These surveillance data help characterize trends over time and the magnitude of firearm-related mortality and identify groups at risk. However, further efforts to improve our understanding of firearm-related deaths and injuries, such as expansion of current surveillance to include information about morbidity associated with firearms and additional epidemiologic research to identify modifiable individual and societal risk factors, are necessary.

Argon laser radiation of human clots: differential photoabsorption in red cell rich and red cell poor clots.

Since argon laser radiation (454-514 nm) can vaporize human clots, we determined whether the absorption of laser energies can differ among different types of blood clots. Thus we performed spectrophotometric studies and examined the ability of this laser to penetrate red cell rich and red cell poor clots. Fifty-four red cell rich and red cell poor clot samples, varying in depth from 1.8 to 5.0 mm, were subjected to 3, 5 and 7 watts from an argon laser beam. At a given power intensity, the deeper the red cell rich clot, the longer was the time needed to penetrate the clot. The higher the power used, the shorter was the red clot penetration time. In contrast, all power levels used up to 5 minutes did not penetrate any of the varying depths of red cell poor clots. Spectrophotometrically, the red cell rich clot had an absorption curve typical of hemoglobin pigment while the red cell poor clot, in the absence of hemoglobin, had poor absorption between 350 and 600 nm and was unable to absorb argon laser energies. Thus, the argon laser provides a therapeutic modality for human red cell rich clot dissolution but the present approach does not appear to be effective against red cell poor clots.

Effects of laser radiation on the morphology of human coronary atherosclerotic disease.

Laser energy delivered through optical fibers can produce potent controlled thermal dissolution of human coronary obstructive disease, thus widening the stenotic vascular lumen. The ease of vaporization and penetration depends not only on the physical properties of the laser beam but also on the physical characteristics of the atherosclerotic plaque. Lipid-laden plaques are more easily vaporized compared with plaques that are heavily calcified. In atherosclerotic animal models studied in vivo, laser radiation produced a charred lining around the evacuated area and rapid regeneration of a new endothelial lining. After several weeks, the laser-induced crater was still evident, and thrombogenesis was not a significant complication. Focal aneurysmal dilatation may develop when there is thermal injury of the medial layer, and acute perforation can occur if severe laser burn is extended beyond the adventitial layer. Further technical advances and achievements are needed before laser recanalization becomes a clinical reality.

Laser therapy of coronary artery obstructions.

Laser energies can be transmitted through flexible optical fiber to vaporize and penetrate coronary atherosclerotic and thrombotic obstructions. There are risks and complications involved in this therapy, however, including perforation, aneurysm formation, and thromboembolic risks, and further research is needed to render the laser recanalization procedure safe.

Rotational invariants for polarized Raman spectroscopy.

A new method has been developed to determine an orientation-independent Raman scattered intensity based on various polarized Raman measurements. The equivalent term in infrared spectroscopy is the structural absorbance, which has existed for many years. As with the structural absorbance, the calculated Raman intensity allows one to observe spectral changes that are due uniquely to morphological changes in a set of different samples in the presence of orientation differences. The full theoretical development is presented, followed by an example based on a set of polymer fibers processed under different conditions leading to different morphologies and degrees of molecular orientation.

Determination of the molecular orientation of poly(propylene terephthalate) fibers using polarized Raman spectroscopy: a comparison of methods.

For the first time, four different methods to determine the degree of molecular orientation from polarized Raman spectroscopy measurements are compared. The great influence of molecular orientation on the properties of polymers has driven the development of multiple experimental techniques and procedures. This study is based on the C(1)-C(4) ring stretching vibration of poly(propylene terephthalate) (PPT) at 1614 cm(-1). It is shown that simply ratioing the band intensity obtained with the polarization parallel and perpendicular to the unique axis of the sample provides a good qualitative method to observe the evolution of orientation in a series of similar samples. To quantitatively compare the degree of orientation one needs to utilize a more complex method yielding the second- and fourth-order parameters of the orientation distribution function (P(2) and P(4), respectively). To date, most studies have been based on the assumption of a cylindrically symmetric polarizibility tensor. It is shown that this assumption is highly questionable although this method has been used fairly successfully in the past. This method results in orientation parameters that are clearly different from those obtained with the two more complex procedures. The most complex method, both theoretically and experimentally, requires the most measurements per sample. Major problems have occurred when trying to calculate the desired parameters, in particular for samples with high birefringence. These problems are related to experimental complexities occurring for measurements when the samples are tilted with respect to the polarization direction of the incident light. These measurements are replaced by a simple determination of depolarization ratio in the third method. This method assumes that the depolarization ratio is independent of changes in molecular orientation and structure. It was found that this assumption is not correct. Thus, the most complex method is the method of choice to quantitatively determine the second- and fourth-order parameters of the orientation distribution function, unless one has knowledge of the depolarization ratio of each sample being studied. That knowledge permits the use of an experimentally simpler method to obtain the desired parameters.

Effects of laser irradiation on human erythrocytes: considerations concerning clinical laser angioplasty.

Recent studies demonstrate the potential use of laser to vaporize human coronary atherosclerotic plaques. The laser energy is transmitted through flexible quartz fiber and discharged intravascularly. Since red blood cells could be exposed to intense heat, we examined effects of laser irradiation on human erythrocytes. Blood was obtained and placed in 5 ethylene diaminetetracidic acid (EDTA) vials for each normal donor. A flexible 400 microns diameter core quartz fiber coupled to an argon-ion laser source was positioned 1 cm above the surface of 1.5 ml blood. Four vials were exposed to 5 W laser beam for 5, 10, 15, or 20 s; the remaining vial was left untreated. Packed cell volume fell primarily during the first 5 s of laser exposure (p less than 0.01) and plateaued beyond 5 s. Plasma hemoglobin (Hgb) rose progressively with each increased duration of exposure (p less than 0.01). This study indicates that lysis of erythrocytes occurs in cells exposed directly to the laser beam. However, beyond the direct beam, damage to red cell membrane took place as evident by progressive Hgb leakage into plasma despite no further cell lysis. These observations require consideration during clinical laser angioplasty.

The role of families and care givers as risk and protective factors in preventing youth violence.

This paper reviews research which discusses the risk and protective functions that families and other caregivers provide in influencing the development of aggressive behavior in youth. Currently, there is an emphasis on providing violence prevention programs in the school environment, typically with little parental or caregiver involvement. By enhancing the role of families and caregivers in youth violence prevention programs, we assert that an unique opportunity exists to both address specific risk factors for violence while enhancing the protective features of the family. Relatedly, the risk literature on youth violence indicates that the most influential risk factors (i.e., the family, community, and peers) have their principle impact on youth aggression outside the school. We suggest a shift in the focus of violence prevention programming that is more inclusive of families as both a risk and protective agent. In support of this position, relevant theory and reviews of exemplary family-involved programs are offered. Challenges to involving youth caregivers are identified and recommendations for overcoming those challenges suggested. Last, recommendations for future research and public policy in the prevention of youth violence are offered.

Help-seeking behavior prior to nearly lethal suicide attempts.

The association between help-seeking and nearly lethal suicide attempts was evaluated using data from a population-based, case-control study of 153 13- to 34-year-old suicide attempt case-patients treated at emergency departments in Houston, Texas, and a random sample of 513 control-subjects. Measures of help-seeking included whether the participant sought help for health/emotional problems in the past month, type of consultant contacted, and whether suicide was discussed during the interaction. Overall, friends/family were consulted most frequently (48%). After controlling for potential confounders, case-patients were less likely than control-subjects to seek help from any consultant (OR = 0.5, 95% CI = 0.3-0.8) or a professional (e.g., physician, counselor) consultant (OR = 0.5, 95%CI = 0.29-0.8). Among those who sought help, case-patients were more likely than to discuss suicide (OR = 2.6, 95% CI = 1.2-5.4), particularly with professionals (OR = 11.8, 95% CI = 3.2-43.2). Our findings suggest that efforts to better understand the role of help-seeking in suicide prevention, including help sought from family and friends, deserves further attention.