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Biomedical subjects

S M Reed

Publications and source records attributed to S M Reed.

89 records · Page 5Linked to original sources
PubMed1982

Urinary indices for differentiation of prerenal azotemia and renal azotemia in horses.

The urine urea nitrogen/plasma urea nitrogen ratio (Uun/Pun), urine creatinine/plasma creatinine ratio (Ucr/Pcr), urine osmolality/plasma osmolality ratio (Uosm/Posm), and fractional excretion of filtered sodium (FENa) were evaluated in 16 horses with acute azotemia to ascertain the significance of each index in the differentiation of prerenal azotemia from renal azotemia. Renal azotemia was diagnosed when renal biopsy or postmortem histologic examination demonstrated evidence of organic renal disease or when azotemia was found in the presence of isosthenuria. The diagnosis of prerenal azotemia was based on the absence of renal histologic lesions or stabilization of blood urea nitrogen and serum creatinine soon after therapy. In 10 horses with renal azotemia, Uun/Pun was 2.1-14.3, Ucr/Pcr was 2.6-37.0, Uosm/Posm was 0.8-1.7, and FENa was 0.08-10.0. In 6 horses with prerenal azotemia, Uun/Pun was 15.2-43.7, Ucr/Pcr was 51.2-241.5, Uosm/Posm was 1.7-3.4, and FENa was 0.02-0.50. The values for each of these indices differed significantly between the 2 groups of horses (P less than 0.05). It was concluded that these indices were of value in the early classification of renal failure in the horse and that this information could be utilized in planning of therapy of acute azotemia in the horse.

Acute Kidney Injury↗
PubMed1982

Isolation of equine neutrophils and analysis of functional characteristics by chemiluminescence and bacterial assays.

Equine neutrophils (PMN) were isolated to greater than 99% purity by isopyknic sedimentation on coated colloidal silica particles. A cell recovery of 84.7 +/- 4.0%, with a viability of greater than 99%, was observed with this method. The isolated PMN were compared with mixed population of equine peripheral leukocytes with respect to functional integrity by chemiluminescence and bactericidal assays. There was no significant difference (P less than 0.01) observed in either assay between the isolated equine PMN and the mixed-cell populations. The methods used in both the isolation as well as the functional characterization of the equine PMN, were rapid and highly reproducible and should readily find use in clinical and research laboratories. It is now feasible to rapidly assess equine PMN integrity in those cases which warrant this type of study. This is the first direct comparison of the chemiluminescence assay with the microbicidal assay, using equine PMN.

Animals↗
PubMed1971

Bacteriophage and the toxigenicity of Clostridium botulinum type C.

Nontoxigenic and bacteriophage-sensitive bacterial cultures have been isolated from toxigenic Clostridium botulinum type C, strain 468C, after treatment with either ultraviolet light or acridine orange. Two bacteriophages, designated CEbeta and CE(gamma), were isolated from toxigenic strain 468C. Both of these bacteriophages were capable of infecting the nontoxigenic type C cultures, but only bacteriophage CEbeta was involved in the change from nontoxigenicity to toxigenicity.

Acridines↗
PubMedDate not supplied

Subdural injection of contrast medium during cervical myelography.

Three patients (1 dog, 2 horses) are described where myelography was complicated, purportedly by injection of contrast medium into the meninges superficial to the subarachnoid space. Contrast medium injected in this location in a cadaver tended to accumulate dorsally within the vertebral canal, deep to the dura mater but superficial to the subarachnoid space. The ventral margin of the pooled contrast medium had a wavy or undulating margin and the dorsal margin was smooth. Pooled contrast medium was believed to be sequestered within the structurally weak dural border cell layer between the dura mater and arachnoid membrane, or the so-called subdural space.

Animals↗
PubMedDate not supplied

Epidemiology of equine protozoal myeloencephalitis in North America based on histologically confirmed cases. A report.

Following a workshop on equine protozoal myeloencephalitis (EPM) convened at the Veterinary Medical Forum of the American College of Veterinary Internal Medicine in 1988, this survey of EPM in North America was developed. It is based upon 364 histologically confirmed case records from California, Florida, Illinois, Kentucky, New York, Ohio, Oklahoma, Ontario, Pennsylvania, and Texas up to 1988. The highest rate of infection was found in young Thoroughbred, Standardbred, and quarter horses. Differences in geographic location, sex, and month (season) of infection were not discernible. This report, the first comprehensive survey of EPM in North America, is intended to serve as a basis for evaluating future changes in prevalence and spread of EPM.

Animals↗
PubMedDate not supplied

Nephrogenic diabetes insipidus in sibling colts.

Nephrogenic diabetes insipidus was diagnosed in two full sibling Thoroughbred colts. Each colt had a history of excessive urination. Extreme polydipsia (greater than 80 L per day) was documented in both colts. Inability to concentrate urine in response to water deprivation, infusion of hypertonic saline, or exogenous vasopressin administration indicated insensitivity of the collecting duct epithelial cells to vasopressin. A diagnosis of nephrogenic diabetes insipidus was further supported by a normal increase in plasma vasopressin concentration after water deprivation in the one colt in which such testing was pursued.

Animals↗
PubMedDate not supplied

Necrotizing enterocolitis in horses: a retrospective study.

The clinical and clinicopathologic characteristics of fatal necrotizing enterocolitis were examined in 16 horses (age 4 months to 12 years). At initial presentation, 8 of 16 horses were pyrexic (median temperature, 38.4 degrees C; range, 33.8 to 40.6 degrees C); all 16 were tachycardic (median heart rate, 93 bpm, range, 66 to 138 bpm); 13 of 16 were tachypneic (median heart rate, 36 bpm, range, 16 to 80 bpm), dehydrated, and had discolored mucous membranes. All horses that were pyrexic were also tachycardic and tachypneic. PCV was high (> 45%) in 14 horses. Six horses were leukopenic (< 5,000 cells/microL); 12 were neutropenic (< 2,300 cells/microL), and 14 had > 100 band neutrophils/microL. Twelve horses were acidemic (pH < 7.37; range, 6.88 to 7.33) and the venous bicarbonate concentration was low (< 23 mEq/L) in 14 horses. Median anion gap in 16 horses was 31.5 mEq/L (> 15 mEq/L in 15 horses). Eleven of 16 horses were hyponatremic (< 137 mEq/L), 1 horse was hypernatremic (> 143 mEq/L), 3 were hypokalemic (< 3.2 mEq/L), 6 were hyperkalemic (> 4.5 mEq/L), and 14 were hypochloremic (< 98 mEq/L). Serum creatinine concentrations were high (> 1.4 mg/dL) in 15 horses. Abdominal fluid was examined in 12 horses 4 had total protein concentrations > 2.5 g/dL and 6 had nucleated cell counts > 5,000/ microL and < 10,000/microL; none had > 10,000/microL. Eight of 12 samples revealed a nondegenerate neutrophilia (> 50%). Abdominal fluid collected from 4 horses immediately before death was normal in 2 horses and indicative of suppurative inflammation in 2. All 8 horses tested had low or nonexistent serum immunofluorescent antibody titers to Ehrlichia risticii. Four of 16 horses had Salmonella spp isolated from feces or tissues. All 16 horses either died (5 of 16; 31%) or were euthanized because of a grave prognosis. Median time to death was 45.5 hours (range, 7 to 113 hours) from the time of admission. Death was preceded by severe abdominal pain in 14 horses. Fatal necrotizing enterocolitis of horses is characterized by a brief course, profound dehydration, electrolyte derangements, acid-base abnormalities, and terminally, severe abdominal pain. Abdominal fluid analysis was frequently not indicative of the severity of disease.

Acid-Base Equilibrium↗
PubMedDate not supplied

Development and evaluation of a Sarcocystis neurona-specific IgM capture enzyme-linked immunosorbent assay.

Equine protozoal myeloencephalitis (EPM) is a serious neurologic disease of horses caused primarily by the protozoal parasite Sarcocystis neurona. Currently available antemortem diagnostic testing has low specificity. The hypothesis of this study was that serum and cerebrospinal fluid (CSF) of horses experimentally challenged with S neurona would have an increased S neurona-specific IgM (Sn-IgM) concentration after infection, as determined by an IgM capture enzyme linked immunoassay (ELISA). The ELISA was based on the S neurona low molecular weight protein SNUCD-1 antigen and the monoclonal antibody 2G5 labeled with horseradish peroxidase. The test was evaluated using serum and CSF from 12 horses experimentally infected with 1.5 million S neurona sporocysts and 16 horses experimentally infected with varying doses (100 to 100,000) of S neurona sporocysts, for which results of histopathologic examination of the central nervous system were available. For horses challenged with 1.5 million sporocysts, there was a significant increase in serum Sn-IgM concentrations compared with values before infection at weeks 2-6 after inoculation (P < .0001). For horses inoculated with lower doses of S neurona, there were significant increases in serum Sn-IgM concentration at various points in time after inoculation, depending on the challenge dose (P < .01). In addition, there was a significant increase between the CSF Sn-IgM concentrations before and after inoculation (P < .0001). These results support further evaluation of the assay as a diagnostic test during the acute phase of EPM.

Animals↗
PubMedDate not supplied

Diagnostic validity of electroencephalography in equine intracranial disorders.

Electroencephalography (EEG) is a valuable diagnostic test to identify functional disturbances in brain activity. The purpose of this study was to assess the validity of EEG as a diagnostic indicator of intracranial diseases in horses. The validity of EEG was estimated by comparing clinical, clinicopathologic, and histopathologic findings to EEG findings in 20 horses examined for seizures. collapse, or abnormal behavior between 1984 and 1997. A bipolar left-to-right, back-to-front montage and a bipolar circular montage were recorded from sedated (4) and anesthetized (16) horses. Visual and semiquantitative masked analysis of EEG recording Ist was validated on 10 horses presented for problems other than intracranial diseases. EEG pattern was normal in 7 of the 20 clinically affected horses. Abnormal EEG patterns included high-voltage slow waves and discrete paroxysmal activity with or without generalized activity in 13 horses. Histopathologic diagnoses in 10 horses included meningoencephalitis, neuronal necrosis, congenital anomalies. cerebral edema. and abscess. All of these horses had abnormal EEG patterns (sensitivity, 100%) with a positive neuroanatomic correlation in 7 animals. Localization of histopathologic and EEG abnormalities did not correlate in 15% of the horses (3/20). The cause of neurologic signs could not be explained at postmortem examination in 10 animals and the EEG pattern was normal in 7 of these horses (specificity, 70%). In conclusion, equine EEG was a sensitive tool in the diagnosis of intracranial disorders.

Animals↗