Diabetes mellitus in Hopi and Navajo indians. Prevalence of microvascular complications.

In a cross-sectional study of Hopi and Navajo Indians with non-insulin-dependent diabetes mellitus, we found vascular complications to be strongly related to the duration of diabetes. In patients with diabetes of at least 10 yr duration, retinopathy was found in 57%, nephropathy in 40%, peripheral neuropathy in 21%, and peripheral vascular disease in 28%. For the Hopi and Navajo, the duration-specific prevalence rates of microvascular disease were very similar to prevalence rates found in many other populations. Thus we question the concept, based on reports in the late 1960s, that the Hopi and Navajo Indians have hyperglycemia as an isolated chemical abnormality unaccompanied by other manifestations of diabetes mellitus.

Base-line model for identifying the bioaccumulation potential of chemicals.

The base-line modeling concept presented in this work is based on the assumption of a maximum bioconcentration factor (BCF) with mitigating factors that reduce the BCF. The maximum bioconcentration potential was described by the multi-compartment partitioning model for passive diffusion. The significance of different mitigating factors associated either with interactions with an organism or bioavailability were investigated. The most important mitigating factor was found to be metabolism. Accordingly, a simulator for fish liver was used in the model, which has been trained to reproduce fish metabolism based on related mammalian metabolic pathways. Other significant mitigating factors, depending on the chemical structure, e.g. molecular size and ionization were also taken into account in the model. The results (r(2)=0.84) obtained for a training set of 511 chemicals demonstrate the usefulness of the BCF base line concept. The predictability of the model was evaluated on the basis of 176 chemicals not used in the model building. The correctness of predictions (abs(logBSF(Obs)-logBCF(Calc))=0.75)) for 59 chemicals included within the model applicability domain was 80%.

A hospital-based survey of radiological sacroiliitis and HLA-B27 and Cw2 in Navajo and Hopi Indians.

The frequency of radiological sacroiliitis and its association with HLA-B27, Cw1, and Cw2 were determined in Navajo and Hopi Indians coming to a community hospital. In the Navajo, the phenotype frequency of HLA-B27 was 36% and the frequency of sacroiliitis, 11%. In contrast, among the Hopi, the phenotype frequency of HLA-B27 was 9% and the frequency of sacroiliitis, 4%. Of the Navajo men, who had sacroiliitis and were HLA typed, 83% were HLA-B27 positive. The increased frequency of radiological sacroiliitis and were HLA typed, 83% were HLA-B27 positive. The increased frequency of radiological sacroiliitis in the Navajo was felt to be related to the high frequency of HLA-B27 and Reiter's syndrome in this population. HLA-B27, HLA-Cw1, and HLA-Cw2 are known to be in linkage disequilibrium, and about one-half of the men with sacroiliitis from both tribes had concurrence of HLA-B27 and HLA-Cw2.

Detection of Barrett's adenocarcinoma of the gastric cardia with sucrase isomaltase and p53.

BACKGROUND: Routine surveillance for dysplastic epithelium in patients with Barrett's esophagus has markedly improved prognosis. Many patients with short segments of Barrett's mucosa near the esophagogastric junction remain undiagnosed and at risk for the development of Barrett's adenocarcinomas (BA). Sucrase isomaltase (SI), an intestinal enzyme, is highly expressed in intestinal-type Barrett's mucosa and frequently expressed in dysplastic Barrett's mucosa and BA. Sucrose isomaltase is not expressed in normal esophageal or gastric mucosa. Alterations in the p53 tumor suppressor gene are frequent events in dysplastic Barrett's mucosa and BA and result in nuclear protein accumulation. The purpose of this study was to determine the presence or absence of these markers of Barrett's mucosa in adenocarcinoma of the esophagogastric junction or cardia. METHODS: Expression of SI and p53 were examined in 40 BAs and 25 cardia adenocarcinomas using immunohistochemical techniques. RESULTS: Sucrose isomaltase analysis revealed positive staining in 55% (22/40) of the BAs and 44% (11/25) of the cardia adenocarcinomas. Of 14 cardia adenocarcinomas that were SI negative, 100% (14/14) had no associated Barrett's mucosa. However, in 21 cardia adenocarcinomas with no associated Barrett's mucosa, 7/21 (33%) were SI positive. This suggests that SI-positive tumors may represent BA without the standard definition of Barrett's esophagus being met. P53 was present in 65% of BAs and 64% of cardia adenocarcinomas, demonstrating the importance and similarity of this gene alteration in both tumor types. Staining was positive for SI or p53 in 77% (50/65) of all tumors. Tumors of lower stage expressed SI more often than higher stage tumors. CONCLUSIONS: These data suggest that a subset of cardia adenocarcinomas represent BAs. Surveillance endoscopy incorporating additional esophagogastric junction biopsies and assessment of SI or p53 may improve detection of intestinalized Barrett's mucosa and early dysplastic changes.

The development of an implantable artificial lung.

This report describes the development of an implantable gas exchange device. The device is composed of hollow fiber elements wound around a central open core enclosed in a compliant outer casing, offering very low resistance to blood while providing adequate gas exchange. The purpose of this study was to determine if this device design can completely support the gas exchange requirements of a large animal when the device is placed in series with the main pulmonary artery (PA). Six 40-80 kg adult sheep were used. The device was placed with vascular grafts anastomosed end to side on the proximal and distal main PA. The study began with the entire right ventricular blood flow being diverted through the device by occlusion of a snare around the PA between the vascular grafts. Total gas exchange then was provided by the device and the endotracheal tube was clamped. Results showed that this pumpless potentially implantable device is capable of completely supporting the gas exchange requirements of the experimental animals for up to 8 hours in the acute setting without significant change in cardiac index (CI) and oxygen consumption (VO2) compared with baseline. CI = 55.0 +/- 17.0 cc/min/kg versus 45.0 +/- 17.3 cc/min/kg. VO2 = 1.90 +/- 0.96 cc O2/min/kg versus 2.08 +/- 0.54 cc O2/min/kg.

Review of whole-organism bioassays: soil, freshwater sediment, and freshwater assessment in Canada.

Whole organism bioassays for the assessment of soil, freshwater sediment, and freshwater quality were evaluated for their application in the assessment and remediation of contaminated sites in Canada under the National Contaminated Sites Remediation Program. Using 3 essential and 12 desirable methodological criteria, bioassays were categorized as currently usable, prototype, or under development. Based on further considerations related to bioassay application, a battery of usable screening and definitive tests was recommended (with suggestions for augmentation) for each medium. Of the 18 bioassays reviewed for soil quality assessment, 6 were usable, 5 were prototypes, and 7 were under development. Battery screening and definitive tests included 14-day Eisenia andrei survival, 120-hr lettuce and radish seedling emergence, and 72-hr Selenastrum capricornutum growth inhibition. Augmentation with the following bioassays was recommended: soil/freshwater bacterial growth, arthropod reproduction, earthworm reproduction, and reproduction of other soil-dependent organisms. Of the 9 bioassays reviewed for freshwater sediment quality assessment, 1 was usable, 2 were prototypes, and 6 were under development. Three bioassays in the latter two groups were considered usable with the imminent completion of research underway. Screening tests selected included 10-day Chironomus tentans survival, 10-day Hyalella azteca survival, 10-day Hexagenia spp. survival, and 72-hr S. capricornutum growth inhibition. Definitive tests included screening tests, substituting 28-day H. azteca sexual maturation for 10-day survival. Augmentation with the following bioassays was recommended: sediment/freshwater bacterial test, 28-day Tubifex tubifex reproduction, and rooted aquatic plant growth. Of the 25 bioassays considered for freshwater quality assessment, 8 were usable, 7 were prototypes, and 10 were under development. Screening tests selected included 72-hr S. capricornutum growth inhibition; 48-hr Daphnia sp. survival, and 5- and 15-min Photobacterium phosphoreum bioluminescence. Definitive tests included first screening test, 7-day Ceriodaphnia dubia, 7-day fathead minnow larval survival, or 96-hr rainbow trout survival. Augmentation with the following bioassays was recommended: Brachionus calyciflorus 24-hr survival, 48-hr reproduction; freshwater bacterial growth; and aquatic vascular plant growth.

High frequency of HLA-B27 and Reiter's syndrome in Navajo Indians.

Eighteen cases of Reiter's syndrome were found in a population of approximately 6,000 Navajo Indians. The phenotype frequency of HLA-B27 in this population was found to be 36%. The area in which these people live is endemic for shigellosis, Shigella flexneri being the most common species isolated. Presumably the high frequency of HLA-B27 and shigella infections account for the high incidence and prevalence of Reiter's syndrome in this population.

An intrapleural lung prosthesis: rationale, design, and testing.

Extracorporeal life support (ECLS or ECMO) is standard treatment for severe respiratory failure but poses many contraindications to future lung transplantation. The solution to this dilemma is the implantable gas exchange device (IGED) or artificial lung. Preliminary efforts to create such an artificial lung have been made since 1970 and include designs involving single devices, intravascular devices (i.e., IVOX), and combination heart-lung devices. Stringent requirements govern the design of such a device, the most important of which are high gas exchange efficiency, low resistance to blood flow, and size. This paper describes such a device. It incorporates large diameter inflow and outflow ports in close proximity and a low resistance wound hollow fiber core encapsulated in a compliant outer shell which conserves the work of the right ventricle. In a large animal model (adult sheep) this device was connected in line with the main pulmonary artery in series with the native lungs. This configuration has the advantages of using the lungs as an embolic filter, perfusing the lungs with fully oxygenated blood, and maintaining the integrity of the anatomy necessary for transplant. Laboratory experiments have run > 8 h. Preliminary data show that the animals have remained hemodynamically stable while the devices have supported the animals completely by supplying 100% O2 saturation with PO2 values ranging from 250-350 mm Hg. Additionally, this model makes possible the study of respiratory failure without introducing other variables such as extracorporeal circuits or pumps. The other metabolic, endocrine, and reticuloendothelial functions of normal and injured lungs can now be studied more precisely by excluding these variables.(ABSTRACT TRUNCATED AT 250 WORDS)

"Navajo arthritis" reconsidered: relationship to HLA-B27.

"Navajo arthritis" was described in 1971 as an acute, self-limited, asymmetric polyarthritis of unknown etiology seen in Navajo Indian patients. This description was before published accounts relating HLA-B27 to certain seronegative arthropathies. Review of 92 cases of arthritis seen between 1977 through 1979 in adult Navajo Indians revealed 16 cases of complete Reiter's syndrome, 6 cases of incomplete Reiter's syndrome, and 7 cases of ankylosing spondylitis. The phenotype frequency of HLA-B27 in this Navajo population is 36% and, of the Reiter's syndrome and ankylosing spondylitis patients tested, 85% were found to be HLA-B27 positive. We suggest that "Navajo arthritis" may not be a unique form of arthritis affecting only the Navajo, but a variant of either Reiter's syndrome or ankylosing spondylitis.

The HLA loci of th Hopi and Navajo.

The purpose of this paper is to present the genetic distribution at the HLA-A, B, C, and DR loci in the Hopi and the Navajo. A sample of 100 out-patients from each tribe was selected at the Public Health Service Indian Hospital in Keam's Canyon, Arizona, and was typed for the antigens at the four loci. The distributions of the alleles and the haplotypes are similar in each tribe. A distance measure, f, confirms the genetic similarity of the two populations. It is concluded that the great cultural diversity of the Hopi and the Navajo is the result of a cultural evolution and diversification that has greatly outstripped the genetic evolution at the major histocompatibility loci over the past 20,000 years.