Phylogenetic relationships of bolitoglossine salamanders: a demonstration of the effects of combining morphological and molecular data sets.

We analyzed sequence data for 555 bp of the mitochondrial gene cytochrome b in plethodontid salamanders, taken from 18 ingroup (tribe Bolitoglossini) and 4 outgroup (tribe Plethodontini) taxa. There were 257 variable sites, of which 219 were phylogenetically informative. Sequence differences among taxa exceeded 20%, and there were up to 15% amino acid differences among the sequences. We also analyzed 37 morphological (including karyological) characters, taken from the literature. Data were analyzed separately and then combined using parsimony and likelihood approaches. There is little conflict between the morphological and DNA data, and that which occurs is at nodes that are weakly supported by one or both of the data sets. Treated separately, the morphological and DNA data provide strong support for some nodes but not for others. The combined data act synergistically so that good support is obtained for nearly all of the nodes in the tree. Recent divergences are supported by silent transitions, and older divergences are supported by a combination of morphological, karyological, DNA transversion, and amino acid changes. Eliminating silent changes from the DNA data improves the consistency index and improves some bootstrap and decay index values for several deeper branches in the tree. However, the combined data set with all characters included provides a better supported tree overall. Maximum likelihood and parsimony with all of the data give not only the same topology but also remarkably similar branch lengths. Results of this analysis support the monopoly of the supergenera Hydromantes and Batrachoseps, and of a sister group relationship of Batrachoseps and the supergenus Bolitoglossa (represented in this study one species of the genus Bolitoglossa).

Spinal brucellosis in a southern California resident.

Dynamic changes in patient demography that are currently altering the regional epidemiology of brucellosis attest to the need for physicians to reacquaint themselves with a disease that has been largely forgotten in the United States. This is especially the case in California, which has a large immigrant population and where brucellosis clearly appears to have evolved from an occupational to a food-borne illness. In our recent clinical experiences with several cases of brucellosis, food-borne transmission of the organism is the presumptive cause of the disease, as no causes were associated with occupational risks for exposure to the organism. This suggests that given a clinical history consistent with brucellosis, physicians working with patient groups at risk for food-borne exposure must inquire about the ingestion of unpasteurized dairy products specifically and early during the patient visit. A history of travel to areas endemic for brucellosis may further aid diagnosis. Although a predominance of nonspecific clinical signs and symptoms (such as fevers or arthralgias) often makes the clinical diagnosis difficult, the frequency and characteristic patterns of localized disease should heighten clinicians' index of suspicion and lower the threshold for a serologic investigation. Prominent musculoskeletal complaints (especially back pain) accompanied by constitutional symptoms such as fever, malaise, and weight loss may be consistent with brucellosis and a history of unpasteurized dairy ingestion should be elicited. Radiographic evidence that localizes the source of back pain as caused by sacroiliitis or spondylitis is highly suggestive of brucellosis in appropriate patients. In such cases, serologic tests should be persuaded early if warranted by the clinical impression.

The medical director in the multi-level long-term care facility.

This article describes the medical director's role in a multi-level long-term care facility, the continuing care retirement facility (CCRC). The history of CCRCs, different types, services available, and demographics of residents are discussed. Special attention is given to the role that the medical director plays in providing primary care services for the highest functioning of residents at a CCRC.

Plasma specific gravity for identifying hypovolaemia.

To define ranges of plasma specific gravity useful for identifying volume depletion in older adults, plasma specific gravity was measured in 170 young adults (mean age 28 years) and 100 retirees (mean age 81 years), and ranges of values likely to be associated with volume depletion were defined. Subsequently, measurements of plasma specific gravity were made in 68 older emergency room (ER) patients (mean age 74 years), a few of whom had obvious reasons for being hypovolaemic, e.g. dehydrating diarrhoea, and these results were compared to those for the control groups. Ranges for plasma specific gravity useful for identifying volume depletion were designated as possible hypovolaemia (1.0265-1.0279), probable hypovolaemia (1.0280-1.0294), and hypovolaemia (> or = 1.0295). Using these definitions, there were more older ER patients compared to both young and old control group subjects, respectively, with probable hypovolaemia (21% vs. 5% and 8%; p < 0.03) and hypovolaemia (16% vs. 0% and 0%; p < 0.03). This study establishes ranges for plasma specific gravity for young and old adults likely to be associated with hypovolaemia, and shows that based upon measurement of plasma specific gravity, older ER patients may often be hypovolemic even in the absence of obvious fluid-wasting illnesses. Future studies are needed to identify the risk factors for hypovolaemia in ER patients, and more vigorously substantiate the findings of this study.

Molecular genetics of the most endangered canid: the Ethiopian wolf Canis simensis.

The world's most endangered canid is the Ethiopian wolf Canis simensis, which is found in six isolated areas of the Ethiopian highlands with a total population of no more than 500 individuals. Ethiopian wolf populations are declining due to habitat loss and extermination by humans. Moreover, in at least one population, Ethiopian wolves are sympatric with domestic dogs, which may hybridize with them, compete for food, and act as disease vectors. Using molecular techniques, we address four questions concerning Ethiopian wolves that have conservation implications. First, we determine the relationships of Ethiopian wolves to other wolf-like canids by phylogenetic analysis of 2001 base pairs of mitochondrial DNA (mtDNA) sequence. Our results suggest that the Ethiopian wolf is a distinct species more closely related to gray wolves and coyotes than to any African canid. The mtDNA sequence similarity with gray wolves implies that the Ethiopian wolf may hybridize with domestic dogs, a recent derivative of the gray wolf. We examine this possibility through mtDNA restriction fragment analysis and analysis of nine microsatellite loci in populations of Ethiopian wolves. The results imply that hybridization has occurred between female Ethiopian wolves and male domestic dogs in one population. Finally, we assess levels of variability within and between two Ethiopian wolf populations. Although these closely situated populations are not differentiated, the level of variability in both is low, suggesting long-term effective population sizes of less than a few hundred individuals. We recommend immediate captive breeding of Ethiopian wolves to protect their gene pool from dilution and further loss of genetic variability.

Screening techniques for detecting allelic variation in DNA sequences.

This article reviews four 'DNA screening techniques', namely heteroduplex analysis, single-strand conformational polymorphism (SSCP), denaturing gradient gel electrophoresis (DGGE) and temperature gradient gel electrophoresis (TGGE) as tools for the study of allelic variation in natural populations. The resolving power, advantages, and limitations of each technique are discussed and compared. We also provide some criteria for choosing among techniques and illustrate some practical issues with examples taken primarily from our own laboratory experience.

The outcome of CPR initiated in nursing homes.

To determine outcomes following attempted cardiopulmonary resuscitation initiated in nursing homes, we retrospectively reviewed ambulance and hospital records for all 705 people aged 65 or over who underwent attempted resuscitation by ambulance crews in 1987 in Baltimore City and Baltimore County. From medic unit encounter forms we noted whether or not the address of origin was a nursing home and to what hospital the person was taken. Hospital records were then examined to determine outcomes: death in the emergency room, death during consequent hospitalization, or live discharge. Complete information was obtained for all 117 nursing-home residents and for 580 of 588 nonresidents. When attempted resuscitation was begun in a nursing home, only two patients survived to hospital discharge, whereas 61 nonresidents (11%) survived after a mean stay of 14 days. Of the 115 nursing-home residents who did not survive to hospital discharge, 102 (89%) were pronounced dead in the emergency room, two (2%) more died within 24 hours of admission, and the remaining 11 (9%) died after an average stay of five days. Of the 519 nonresidents who died before discharge, 433 (83%) were pronounced dead in the emergency room, 16 (3%) died in the first 24 hours, and 70 (14%) lived an average of nine days. One of the two nursing-home residents who survived was an 87-year-old woman who spent 30 days in the hospital and died eight months after returning to the nursing home, demented, cachectic, with a large sacral pressure sore.(ABSTRACT TRUNCATED AT 250 WORDS)