Overview of the Mars Pathfinder mission and assessment of landing site predictions.

Chemical analyses returned by Mars Pathfinder indicate that some rocks may be high in silica, implying differentiated parent materials. Rounded pebbles and cobbles and a possible conglomerate suggest fluvial processes that imply liquid water in equilibrium with the atmosphere and thus a warmer and wetter past. The moment of inertia indicates a central metallic core of 1300 to 2000 kilometers in radius. Composite airborne dust particles appear magnetized by freeze-dried maghemite stain or cement that may have been leached from crustal materials by an active hydrologic cycle. Remote-sensing data at a scale of generally greater than approximately 1 kilometer and an Earth analog correctly predicted a rocky plain safe for landing and roving with a variety of rocks deposited by catastrophic floods that are relatively dust-free.

Distinct metal cofactor-induced conformational states in the NAD-specific malic enzyme of Escherichia coli as revealed by proteolysis studies.

Evidence is presented for the existence of altered ligand-stabilized conformational states of the NAD-specific malic enzyme (L-malate:NAD+ oxidoreductase (oxaloacetate-decarboxylating), EC 1.1.1.38), of Escherichia coli in the presence of Mg2+ and Mn2+, as identified by their susceptibilities to proteolysis. The rate of tryptic digestion of the enzyme is significantly decreased in the Mg2+-form of the enzyme when the product, NADH, or the allosteric effectors, coenzyme A and aspartate, are present in the digestion mixture. In contrast, little difference in the rate of tryptic digestion is observed in the degree of protection of the enzyme by the two metal cofactors, either alone, or in the presence of the substrates, malate and NAD. The results are consistent with the previously proposed hypothesis of Milne and Cook (Biochemistry 18, (1979) 3604-3610) that Mg2+ and Mn2+ stabilize two distinct conformational states of the enzyme. The results are discussed in relation to the altered kinetic response of the enzyme to substrates and effectors in the presence of the two metal cofactors.

Conservation medicine.

The Field Veterinary Program (FVP) of the Wildlife Conservation Society (WCS) was created in 1989 to combat the wildlife disease and health problems that increasingly complicate the process of wildlife conservation. The FVP provides veterinary services for the more than 300 WCS conservation projects located in more than 50 countries around the world. Most of these projects are in tropical regions and many have a wildlife/domestic livestock component. Wildlife health care provided by the FVP staff includes (1) identifying critical health factors; (2) monitoring health status; (3) crisis intervention; (4) developing and applying new technologies; (5) animal handling and welfare concerns; and (6) training. Additionally, the staff of the FVP give expert advice to many governmental and non-governmental agencies that are involved in setting policies directly related to wildlife health and conservation issues. In this paper, two FVP projects are presented as examples of studies that have increased our understanding of the role wildlife diseases may play in the health of livestock and human populations, as well as the role humans and livestock may play in the health of wildlife populations. Examples of the collaborative work between the FVP staff and scientists from many disciplines (e.g., acarologists, mycobacterium experts, ecologists, and biologists) are also presented.

Comparative analysis of three antifungal susceptibility test methods against prospectively collected Candida species.

We performed antifungal susceptibility tests with cilofungin (LY121019), amphotericin B, and flucytosine against 38 strains of yeasts from patients with esophagitis or fungemia either before, during, or after treatment with cilofungin. Tests were performed using a macrobroth dilution method similar to that proposed by the National Committee for Clinical Laboratory Standards (M27-P) and two microbroth methods. For cilofungin and amphotericin B, minimum inhibitory concentrations from microbroth tests using Antibiotic Medium 3 (AM3) were systematically lower than results from the other two methods that utilized RPMI-1640 medium (RPMI). AM3 did not provide any greater degree of in vitro correlation with clinical results than did RPMI. We conclude that cilofungin and possibly other congeners of the echinocandin class of antifungal agents can effectively be studied using the proposed National Committee for Clinical Laboratory Standards method.

Initial characterization of factors from testicular fluid which alter in vitro androgen secretion by normal rat Leydig cells.

It is known that testicular interstitial fluid (TF) contains thermolabile factors that can alter in vitro production of androgens by the Leydig cells. The net stimulatory activity of this fluid increases in association with the disruption of spermatogenesis. The identity of the active agent(s) in TF is not known. Therefore, the authors used gel-liquid chromatography to initially characterize TF from control and bilaterally cryptorchid animals. The stimulatory activity of TF was retained on Concanavalin A Sepharose columns. Gel filtration on Ultrogel AcA 44 suggested a molecular size between 40 and 90 kD. The unfractionated fluid from control and bilaterally cryptorchid rats, as well as the chromatographic fractions containing stimulatory activity, were further resolved by SDS-PAG electrophoresis. At least three bands representing glycoproteins with apparent molecular size between 57 and 75 kD were seen in all samples containing stimulatory activity. No difference in the pattern of protein bands was seen between TF from control and bilaterally cryptorchid testes. However, samples reduced with beta-mercaptoethanol showed protein bands with apparent molecular size of 78 and 118 kD which were present only in unpurified control TF. These data support the possibility that the stimulatory substance in TF from control and bilaterally cryptorchid testes is a glycoprotein with a molecular size between 57 and 75 kD. Differences in the bioactivity of the unfractionated TF may be due in part to the presence of additional larger protein molecules in the control TF.

Serum proteolytic activity during the growth of C6 astrocytoma.

Tumor growth is dependent on the ability of neoplastic cells to induce angiogenesis. Blood-vessel remodeling requires the reconstruction of the nonfibrous proteins and type IV collagen components of the basement membrane. This study has assessed the influence of the growth of C6 astrocytoma cells in the rat spheroid implantation model on serum general protease and type IV collagenase activity. The results demonstrate that general protease activity increased in serum, reaching maximum values on Day 6 and Day 13 following spheroid implantation, and that type IV collagenase activity increased in serum, obtaining maximum values on Day 8 and Day 15. The measurement of serum proteolytic activity may be of value in the detection of recurrent tumors.

Nutritional status of Head Start and nursery school children. II. Biochemical measurements.

At the beginning of a Head Start and nursery school program in the fall, nursery school children had significantly higher hemoglobin and hematocrit levels and mean corpuscular volume than Head Start children. The latter had a higher mean corpuscular hemoglobin concentration and alpha 1 globulin level. In the spring, at the close of both preschool programs, nursery school children still had higher hemoglobin and hematocrit levels and mean corpuscular volume, and also a higher mean corpuscular hemoglobin and total iron binding capacity. Head Start children exhibiting signs of anemia in the fall were improving in iron status in the spring. Normal blood protein levels for both groups of children indicated adequate protein status. This condition was confirmed by urinary analysis of urea, creatinine, and inorganic sulfate sulfur.

Validation of a quantitative food frequency questionnaire for rapid assessment of dietary calcium intake.

This study tested the accuracy of a quantitative food frequency questionnaire (FFQ) designed to assess the amount of calcium consumed daily and to use as an educational tool in diet counseling and for prescribing calcium supplementation. The subjects were 26 perimenopausal women, aged 48 to 56 years, who were participants in a longitudinal osteoporosis study. Diets of the subjects were studied during the winter and summer of one year. Subjects filled out a food frequency questionnaire and the next week completed 4-day food intake records according to instructions from the researchers. The mean daily intake of calcium estimated from the food frequency questionnaire was 928 mg in the winter and 912 mg 6 months later. Ranges in the winter were 227 to 2,243 mg calcium and in the summer 198 to 3,063 mg calcium. The 53-item FFQ included descriptions of portion sizes and a calcium index for each item and had options for two frequency periods. The calcium level estimated from the questionnaire correlated (r = .73 in winter and r = .84 in summer) with the estimated amount from 4-day records. A seasonal difference was not found. The brief time (less than 5 minutes by a dietitian) required to calculate the amount of calcium consumed daily from the food frequency questionnaire could make it an important clinical tool.

Nutritional status of Head Start and nursery school children. I. Food intake and anthropometric measurements.

Food intakes and anthropometric measurements of Head Start and nursery school children were compared in the fall and spring. Meals consumed at Head Start improved low calcium and ascorbic acid intakes. Iron intakes were low among both groups of children during both seasons. All children had high protein intakes in the fall and spring. Nursery school children consumed high levels of calcium and ascorbic acid and received more vitamin and mineral supplements. Anthropometric measurements indicated adequate and similar growth for all children during each season. Dietary intakes of mothers were less satisfactory than those of their children. Head Start mothers had the poorest diets, with frequent low intakes of energy, calcium, iron, vitamin A, ascorbic acid, riboflavin, and thiamin. Iron was the nutrient needed most by both groups of mothers. Nursery school mothers had especially high intakes of ascorbic acid, and consumed more vitamin and mineral supplements than Head Start mothers.

Proteolytic activity during the growth of C6 astrocytoma in the murine spheroid implantation model.

General protease and collagenase IV activity are involved in the remodelling of the vascular basement membrane that occurs during tumor-induced angiogenesis. This study has assessed the level of these enzymes in tumor, peritumoral or contralateral cerebral cortex tissue during the growth of C6 astrocytoma in the rat spheroid implantation model. General proteolytic activity was increased in tumor tissue beginning on day 8 following spheroid implantation, then increased to a maximum value on day 11 and decreased to control values on day 18. A similar pattern was seen for collagenase IV activity but maximal activity occurred on day 13. The peritumor and tumor patterns of activity were similar. General protease activity was increased in the hemisphere contralateral to the tumor suggesting that the growth of C6 astrocytoma in rat brain was influencing biochemical events distant from the tumor. C6 astrocytoma cells orchestrate a cascade of proteolytic events which may play a crucial role in angiogenesis associated with tumor growth in the model system studied.

Serum antigen 85 levels in adjunct testing for active mycobacterial infections in orangutans.

Diagnosis of active mycobacterial disease in orangutans (Pongo pygmaeus) has been impeded by high levels of non-specific intradermal skin test reactivity to mycobacterial antigens. This may be due in part to cross reactivity between antigens, tuberculin concentrations used or other species-specific factors. Antigen 85 (Ag85) complex proteins are major secretory products of actively growing mycobacteria, and measurement of serum Ag85 could provide a method for determining active mycobacterial infections that was not dependent on host immunity. Serum Ag85 was measured by dot-immunobinding assay using monoclonal anti-Ag85, purified Ag85 standard and enhanced chemiluminescence technology in coded serum samples from 14 captive orangutans from a zoo in Colorado, 15 semi-captive orangutans in Malaysia, and 19 free-ranging wild orangutans in Malaysia. Orangutans from Colorado (USA) were culture negative for Mycobacterium tuberculosis and M. avium, although all had laboratory suspicion or evidence of mycobacterial infection; median serum Ag85 was 10 microU/ml (range, <0.25-630 microU/ml). Of the semi-captive orangutans, six were skin test reactive and two were culture positive for M. avium on necropsy. Median serum Ag85 for this group was 1,880 microU/ml (0.75-7,000 microU/ml), significantly higher than that of Colorado zoo or free-ranging Malaysian orangutans. Median serum Ag85 in the latter group was 125 microU/ml (range, 0.75-2,500 microU/ml). These data suggest that suggest that additional studies using more specific reagents and more samples from animals of known status are appropriate.

Periodontal status in snow leopards.

Periodontal examinations were performed on ten 1- to 22-year-old snow leopards (6 males and 4 females), using dentistry methods for determining the plaque and gingival indices. All tooth surfaces were probed, and alveolar bone attachment loss was determined. After subgingival plaque removal, plaque specimens were examined for differential bacterial morphotypes. The small number of leopards evaluated precluded definitive statistical analysis. However, the progression from gingival health to gingivitis to periodontitis was similar to that seen in man. Therefore, the use of plaque index, gingival index, alveolar bone attachment loss, and differential bacterial morphotypes can be used to determine the dental health of snow leopards.

Total ankle arthroplasty.

Ankle arthritis has traditionally been treated surgically with arthrodesis (fusion) after conservative measures have been exhausted. The success of joint arthroplasty in the knee, hip, and shoulder inspired many attempts over the past 30 years to construct a workable ankle prosthesis. The failures of first generation prostheses caused skepticism regarding the feasibility of total ankle arthroplasty (TAR), but the mistakes of the past have been transformed into improvements and modifications. Today's second generation total ankle designs show promise, and outcomes are encouraging. The Agility Ankle (DePuy, Warsaw, IN) designed by Dr. Frank Alvine is featured in this article. The method of implant and postoperative management are reviewed.

Brodifacoum toxicity and treatment in a white-winged wood duck (Cairina scutulata).

A captive white-winged wood duck (Cairina scutulata) with bilateral epistaxis and anemia (packed cell volume = 16%) was treated with injectable and oral vitamin K1 and transfused with 40 ml whole blood. Brodifacoum was detected in blood at 0.002 ppm. The bird made an uneventful recovery. This report illustrates the risk of anticoagulant pest control products in a zoological setting.

Health evaluation of free-ranging and hand-reared macaws (Ara spp.) in Peru.

As part of ongoing ecological studies and reproduction enhancement efforts for macaws in southwestern Peru, a health survey of parent- and hand-reared scarlet macaws (Ara macao) and blue and gold macaws (Ara ararauna) was conducted in 1994. Thirty-three birds were examined during handling procedures, and blood samples were collected from 27 (9 parent reared, 18 hand reared) for laboratory analysis. All but one bird appeared to be in good condition, with no abnormality noted during physical examination. Hematology, plasma chemistries, and plasma vitamin and mineral levels were studied and correlated with the results of bacterial and viral serology. Positive antibody titers for Salmonella and psittacine herpesvirus were found. These diseases have the potential to affect wildlife population dynamics, and Salmonella may have public health significance. Serological tests for avian influenza, infectious laryngotracheitis, paramyxovirus-1, -2, -3, polyoma virus, chlamydiosis, and aspergillosis were negative. Differences in disease prevalence were found between rearing situations.

Detection of elevated levels of circulating antigen 85 by dot immunobinding assay in captive wild animals with tuberculosis.

Antemortem diagnosis of tuberculosis in captive wild animals is often difficult. In addition to the variability of host cellular immune response, which does not always indicate current active infection, reactivity to saprophytic or other mycobacteria is common and may interfere with the interpretation of the intradermal tuberculin skin test. Furthermore, the immobilization required for administering the test and evaluating skin reactions in these animals may result in unacceptable levels of morbidity and mortality, of particular concern in individuals of rare or endangered species. Proteins of the antigen 85 (Ag85) complex are major secretory products of actively metabolizing mycobacteria in vitro. Production of these proteins by mycobacteria during growth in vivo could result in increases in circulating levels of Ag85 in hosts with active tuberculosis. A dot blot immunoassay has been used to detect and quantify circulating Ag85 in captive wild animals with tuberculosis. Elevated levels of Ag85 were observed in animals with active tuberculosis as compared with uninfected animals. Study populations included a herd of nyala (Tragelaphus angasi) (n = 9) with no history of exposure to Mycobacterium bovis. Serum Ag85 levels ranged from <5 to 15 microU/ ml (median, 5 microU/ml). The other group included 11 animals from a mixed collection with a documented history of an M. bovis outbreak. Animals with pulmonary granulomatous lesions (n = 3) had serum Ag85 levels ranging from 320 to 1,280 microU/ml (median, 320 microU/ml). Animals with only chronic mediastinal or mesenteric lymphadenitis (n = 4) had serum Ag85 levels ranging from <5 to 320 microU/ml (median, 52.5 microU/ml). Animals with no lesions present on necropsy (n = 4) had serum Ag85 levels ranging from <5 to 80 microU/ml (median, <5 microU/ml). This assay could provide an important adjunct to intradermal skin testing for antemortem diagnosis of tuberculosis in nondomestic species.

Health evaluation of black-faced impala (Aepyceros melampus petersi) using blood chemistry and serology.

As part of ongoing ecological studies of black-faced impala (Aepyceros melampus petersi) in northern Namibia, blood samples were collected and analyzed from 26 animals captured for translocation in 1992. All animals appeared to be in good condition and no abnormality was noted during physical examination. Serum chemistry and mineral levels were measured and correlated with the results of bacterial and viral serology and were within the normal ranges for domestic ruminants. Antibody titers for infectious bovine rhinotracheitis and bovine viral diarrhea were detected. Serological tests for bluetongue, foot-and-mouth disease, rinderpest, parainfluenza 3, brucellosis, leptospirosis, and anaplasmosis were negative. Significant differences in disease prevalence were not found between sexes.

Health evaluation of free-ranging guanaco (Lama guanicoe).

Twenty free-ranging guanaco (Lama guanicoe) in Chubut Province, Argentina, were immobilized for health evaluations. All but two animals appeared to be in good condition. Hematology, serum chemistry, and vitamin and mineral levels were measured, and feces were evaluated for parasites. Serology tests included bluetongue, brucellosis, bovine respiratory syncitial virus, bovine viral diarrhea/mucosal disease, equine herpesvirus 1, infectious bovine rhinotracheitis, Johne's disease (Mycobacterium paratuberculosis), foot and mouth disease, leptospirosis (17 serovars), parainfluenza-3, and vesicular stomatitis. Blood samples from 20 domestic sheep (Ovis aries) maintained in the same reserve with the guanaco were also collected at the same time for serology tests. No guanaco had positive serologic tests. Sheep were found to have antibody titers to bovine respiratory syncytial virus, Johne's disease, leptospirosis, and parainfluenza-3. There was no apparent difference in external appearance or condition, or statistical difference in blood test values, between the animals that were positive or negative for parasite ova.

Health evaluation of free-ranging rockhopper penguins (Eudyptes chrysocomes) in Argentina.

As part of annual colony counts in Santa Cruz Province, Argentina, a health survey of rockhopper penguins (Eudyptes chrysocomes) was conducted in 1994. Forty-five birds were examined during handling procedures, and blood and fecal samples were collected for laboratory analysis. All birds appeared to be in good condition. No ecto- or endoparasites were found. Hematology, plasma chemistry, and plasma mineral levels were measured and correlated with the results of bacterial and viral serology. Antibodies against Chlamydia sp., avian adenovirus, avian encephalomyelitis virus, infectious bronchitis virus, avian reovirus, and paramyxovirus-1, -2, and -3 were found. Mean plasma chemistry and mineral values differed between individuals testing positive and negative on serologic tests. There was no serologic evidence of exposure to avian influenza virus, duck viral enteritis, infectious bursal disease, infectious laryngotracheitis, Aspergillus sp., or Salmonella pullorum. Trace amounts of endrin were found in the plasma of one bird, but all other chlorinated pesticide and polychlorinated biphenyl levels were below detectable limits.

Immobilization of babirusa (Babyrousa babyrussa) with xylazine and tiletamine/zolazepam and reversal with yohimbine and flumazenil.

Twelve babirusa (Babyrousa babyrussa) (four females/eight males) were immobilized 30 times during a 4-yr interval. Significantly higher premedication and immobilizing doses were needed for females than for males (P < 0.05). An i.m. preanesthetic xylazine dose of 1.88 +/- 0.37 mg/kg (range = 1.20-2.12 mg/kg) was used for females and 1.22 +/- 0.16 mg/kg (range = 0.82-1.43 mg/kg) for males. After xylazine, the animals were induced with i.m. tiletamine/zolazepam; females received 2.20 +/- 0.47 mg/kg (range = 1.78-3.33 mg/kg) and males received 1.71 +/- 0.34 mg/kg (range = 1.08-2.05 mg/kg). Anesthesia was reversed with yohimbine (0.14 +/- 0.03 mg/kg; range = 0.07-0.20 mg/kg) and flumazenil (1 mg flumazenil/20 mg zolazepam) either i.m. or i.v. This anesthetic combination produced smooth induction, good relaxation, and sufficient immobilization to perform routine diagnostic and therapeutic procedures (venipuncture, hoof and tusk trims, transportation, radiographs, ultrasound examination, weight determinations, and skin biopsies). Supplemental ketamine HCl or isoflurane was administered to two animals to effectively deepen or prolong the anesthetic plane, with no resultant adverse effects.