Plasma observations near uranus: initial results from voyager 2

Extensive measurements of low-energy positive ions and electrons in the vicinity of Uranus have revealed a fully developed magnetosphere. The magnetospheric plasma has a warm component with a temperature of 4 to 50 electron volts and a peak density of roughly 2 protons per cubic centimeter, and a hot component, with a temperature of a few kiloelectron volts and a peak density of roughly 0.1 proton per cubic centimeter. The warm component is observed both inside and outside of L = 5, whereas the hot component is excluded from the region inside of that L shell. Possible sources of the plasma in the magnetosphere are the extended hydrogen corona, the solar wind, and the ionosphere. The Uranian moons do not appear to be a significant plasma source. The boundary of the hot plasma component at L = 5 may be associated either with Miranda or with the inner limit of a deeply penetrating, solar wind-driven magnetospheric convection system. The Voyager 2 spacecraft repeatedly encountered the plasma sheet in the magnetotail at locations that are consistent with a geometric model for the plasma sheet similar to that at Earth.     

Protothecosis in a dog

A case of a disseminated algal infection is reported in a young rough-coated collie dog with progressive neurologic deficits, blindness, and hemorrhagic diarrhea. Prototheca zopfii organisms were cultured from feces, urine, and blood. At necropsy, granulomas containing typical organisms were identified within the proximal colon, heart, kidneys, and eyes.     

Evaluation of a short-term saline diuresis protocol for the administration of cisplatin

A study was undertaken to determine the toxic effects of cisplatin, an antineoplastic agent, on canine kidneys and bone marrow when administered during a 6-hour saline diuresis. Cisplatin (70 mg/m2 of body surface) was administered IV to 6 healthy dogs over a 20-minute period after 0.9% NaCl solution (saline) was administered IV for 4 hours at a rate of 18.3 ml/kg/hr. After cisplatin injection, saline diuresis was continued at the same rate for 2 hours. Each dog vomited within 8 hours after the drug was administered. Clinical status, weight gain, and food consumption were normal throughout the 27-day study. All measures of renal function remained unchanged and were within normal limits for 27 days after the drug was administered. Nadirs in the daily neutrophil count were observed on days 6 (3,240 +/- 404/microliters) and 15 (1,196 +/- 275/microliters). There were no important gross or histologic abnormalities referable to cisplatin administration when the dogs were necropsied at the conclusion of the study (day 27). We concluded that cisplatin can be administered safely at a dosage of 70 mg/m2 of body surface, using a short-term diuresis protocol, and that the drug induces a nadir in the neutrophil count on days 6 and 15.     

Weekly administration of low-dose doxorubicin for treatment of malignant lymphoma in dogs

Nine dogs with intermediate- or high-grade lymphoma were prospectively entered into a protocol to be given a total of 15 weekly doses of doxorubicin (10 mg/m2 of body surface, IV) in an attempt to eliminate all clinical evidence of neoplasia, with minimal risk of drug toxicity. Eight of these dogs did not complete the protocol because of progression of the disease. The median number of doses administered to dogs that developed progressive disease before the regimen was completed was 5 (range, 2 to 9). Seven dogs achieved partial (n = 5) or complete (n = 2) remission, with median duration of 14 days (range, 7 to 231 days). The dog that was given all 15 weekly treatments remained in complete remission for 231 days. Complete remission that lasted for 14 days was observed in another dog. Toxicosis developed in 3 dogs; signs of toxicosis were generally mild and included colitis (n = 1), vomiting (n = 1), neutropenia (n = 1), and lethargy (n = 1). The lowest neutrophil count (1,876 cells/microliter) was seen in one dog after 7 doses of doxorubicin were given. Doxorubicin at dosage of 10 mg/m2/wk appears to be safe, but is generally ineffective for treatment of lymphoma.     

Amputation and Cisplatin for Treatment of Canine Osteosarcoma

Seventy-one dogs with histologically confirmed appendicular osteosarcoma were evaluated. Seventeen dogs were treated with amputation and two postoperative [corrected] doses of IV cisplatin given 21 days apart (group 1). Nineteen dogs were treated with IV cisplatin 21 days before amputation, with a second dose given immediately after amputation (group 2). Thirty-five dogs were treated by amputation of the affected limb with no chemotherapy (group 3). The median disease-free interval for group 1 was 226 days, and 177 days for group 2. This was not significantly different. The median survival time was 262 days for group 1, 282 days for group 2 and 119 days for group 3. Group 1 and 2 dogs had survival times that were significantly longer than for dogs in group 3. Two IV courses of cisplatin given before or after amputation appears to improve the survival of dogs with osteosarcoma.     

Uterine Infection Influences Size and Follicular Fluid Composition of the Largest Follicle in Buffalo (Bubalus bubalis)

The effect of uterine infection on size and follicular fluid composition of the largest follicle was studied in buffalo. Reproductive tracts were collected from 102 graded Murrah buffaloes at an abattoir. Uterine infection was diagnosed by physical examination of uterine mucus, white side test and uterine cytology. Samples with pus‐containing mucus, positive reaction on white side test and/or >5% neutrophils were considered to be positive for uterine infection. Diameter of the largest follicle was measured, and follicular fluid was aspirated and assayed for nitric oxide (NO), ascorbic acid (AA), cholesterol, oestradiol (E₂) and progesterone (P₄). Infected buffaloes had smaller‐sized (p < 0.0001) largest follicles than non‐infected buffaloes. Follicular fluid collected from the largest follicle in infected buffaloes had greater (p < 0.0001) NO and P₄ concentrations coincident with lesser AA (p < 0.001), cholesterol (p < 0.0001) and E₂ (p < 0.0001) concentrations. Results indicated that uterine infection has an inhibitory effect on growth of the largest follicle in buffalo. The changes in follicular fluid composition in infected buffaloes suggest that the direct effect of uterine infection on ovarian function may be mediated through an alteration in the follicular microenvironment. Greater NO and lesser AA concentrations in the follicular fluid of infected animals are novel findings.     

Evaluation of a one-hour saline diuresis protocol for administration of cisplatin to dogs.

A study was undertaken to determine the toxic effects of cisplatin, an antineoplastic agent, when administered immediately after a 1-hour saline diuresis. Four treatments with cisplatin (70 mg/m2 of body surface, q 3 wk) were administered IV to 6 healthy dogs over a 20-minute period after 0.9% NaCl (saline) solution was administered IV for 1 hour at a volume of 132 ml (kg)0.75. Each dog vomited at least once within 8 hours after each treatment was administered. Clinical status, body weight, and food consumption were normal throughout the 12-week study for 5 of the 6 dogs. The sixth dog developed acute renal failure and became acutely blind and deaf within 3 days after the fourth treatment with cisplatin. Serum electrolyte, creatinine, and urea nitrogen values remained within established normal limits in all dogs immediately prior to each treatment, and in 5 of 6 dogs evaluated 3 weeks after the final treatment. The serum creatinine value (3.3 mg/dl) obtained from the Beagle euthanatized 2 weeks after the fourth treatment was above established normal values. Despite normalcy for all but 1 of the creatinine values, serum creatinine concentration obtained 3 weeks after the final treatment with cisplatin was significantly (P = 0.0001) higher than pretreatment values. When compared with data from all other evaluation periods, significant decreases in glomerular filtration rate, as determined by exogenous (P less than or equal to 0.0001) and endogenous (P less than or equal to 0.0001) creatinine clearance testing, were identified 3 weeks after the fourth treatment with cisplatin.(ABSTRACT TRUNCATED AT 250 WORDS)     

Use of radionuclide imaging to identify malignant mammary tumor bone metastases in dogs

Radionuclide imaging techniques were used to indicate the location and incidence of bone metastases in 30 dogs with malignant mammary tumors. The method was successful in distinguishing mammary tumor metastases in the sternum of one dog.     

Plasma observations near saturn: initial results from voyager 1

Extensive measurements of low-energy plasma electrons and positive ions were made during the Voyager 1 encounter with Saturn and its satellites. The magnetospheric plasma contains light and heavy ions, probably hydrogen and nitrogen or oxygen; at radial distances between 15 and 7 Saturn-radii (Rs) on the inbound trajectory, the plasma appears to corotate with a velocity within 20 percent of that expected for rigid corotation. The general morphology of Saturn's magnetosphere is well represented by a plasma sheet that extends from at least 5 to 17 Rs, is symmetrical with respect to Saturn's equatorial plane and rotation axis, and appears to be well ordered by the magnetic shell parameter L (which represents the equatorial distance of a magnetic field line measured in units of Rs). Within this general configuration, two distinct structures can be identified: a central plasma sheet observed from L = 5 to L = 8 in which the density decreases rapidly away from the equatorial plane, and a more extended structure from L = 7 to beyond 18 Rs in which the density profile is nearly flat for a distance +/- 1.8 Rs off the plane and falls rapidly thereafter. The encounter with Titan took place inside the magnetosphere. The data show a clear signature characteristic of the interaction between a subsonic corotating magnetospheric plasma and the atmospheric or ionospheric exosphere of Titan. Titan appears to be a significant source of ions for the outer magnetosphere. The locations of bow shock crossings observed inbound and outbound indicate that the shape of the Saturnian magnetosphere is similar to that of Earth and that the position of the stagnation point scales approximately as the inverse one-sixth power of the ram pressure.