PubMed HealthSearch

Biomedical subjects

R C Harvey

Publications and source records attributed to R C Harvey.

At least 19 recordsLinked to original sources

Invasive Haemophilus influenzae disease in adults. A prospective, population-based surveillance. CDC Meningitis Surveillance Group.

OBJECTIVE: To define the incidence of and possible risk factors for invasive Haemophilus influenzae disease in adults. DESIGN: Prospective, population-based surveillance of hospital and referral bacteriology laboratories. SETTING: Metropolitan Atlanta, Georgia community. PATIENTS: All patients with H. influenzae isolated from normally sterile sites (blood, cerebrospinal fluid, joint, pleura) from 1 December 1988 through 31 May 1990. MEASUREMENTS: Isolates of H. influenzae were analyzed for serotype and biotype status, outer membrane proteins, lipooligosaccharide phenotypes, ribotyping patterns and beta-lactamase production. RESULTS: A total of 194 cases of invasive H. influenzae occurred (annual incidence of 5.6 cases/100,000 population), of which 47 (24%) were in adults 18 years old or older (annual incidence 1.7 cases/100,000 adults). Adults with invasive H. influenzae ranged from 18 to 96 years; 79% were women. Bacteremic pneumonia accounted for 70% of the adult cases. Other sources for invasive H. influenzae in adults were obstetric infections, epiglottitis, and tracheobronchitis; one patient had meningitis. Underlying conditions were noted in 92% of the patients. Chronic lung disease was the most common risk factor, but pregnancy (annual incidence, 4.9/100,000 pregnant women), HIV infection (annual incidence, 41/100,000 known HIV-infected adults), and malignancy were also important. Overall mortality was 28% in adults, and over half of pregnancy-related infections resulted in fetal death. Fifty percent of the 40 isolates available for testing were serotype b; 47.5%, nontypable; and 2.5%, serotype f. Sixteen of the 45 isolates (36%) were ampicillin-resistant. Based on biotypes, outer membrane protein profiles, lipooligosaccharide phenotypes, and ribotyping patterns, the type b isolates showed less heterogeneity than the nontypable isolates but were distinguishable from one another. CONCLUSIONS: Adult cases currently represent one quarter of all cases of invasive H. influenzae disease. Half of the reported adult cases were caused by type b H. influenzae, and the rate of ampicillin resistance in H. influenzae isolates from adults was higher than previously reported. Haemophilus influenzae is an important cause of bacteremia in compromised adults.

Adolescent

Precautions when using mask induction.

There are few techniques as frequently employed in veterinary anesthesia that are more dependent on good clinical judgment, technical skill, and finesse than mask induction. The technique can be extremely valuable in selected patients.

Anesthesia, Inhalation

An attempt to eradicate Herpesvirus simiae from a rhesus monkey breeding colony.

In the fall of 1987 an attempt to establish a Herpesvirus simiae (B-virus)-negative rhesus monkey (Macaca mulatta) breeding colony was initiated at the Armstrong Laboratory. A serologic testing program was used to identify all monkeys into groups that were either positive or negative to B-virus based on serologic tests. Segregation of the groups allowed the creation of breeding harems that were exclusively seropositive or -negative to B-virus. Animals that were serologically positive were kept in breeding to maintain infant production levels not unlike those previous to segregation. Decreasing numbers of animals converted to a positive status during the first three serum tests for B-virus in the program. During 1990, an increase in the number of monkeys converting to positive status and the discovery of an indeterminate status demonstrated that latency of B-virus in the rhesus may have the potential to defeat an eradication attempt not conscientiously pursued.

Animal Husbandry

Otoacoustic emission in a dog.

A 7-month-old female Poodle was evaluated for a sound continuously emanating from its left ear. The frequency and intensity of the tone was matched by use of a multifrequency audiometer. The frequency and intensity of the sound were 9,594 Hz and 45.5 decibels sound pressure level, respectively. On the bases of normal brain stem auditory-evoked responses and behavioral response to sound, the dog was believed to have normal hearing in both ears. Emission of sound from an ear, referred to as an otoacoustic emission, is a condition that has been reported in human beings and small animals. Successful treatment in human patients with drugs and masking sounds is difficult, and treatment has not been reported in animals. This condition in dogs is not considered life-threatening.

Animals

Characterization of a candidate bcl-1 gene.

The t(11;14)(q13;q32) translocation has been associated with human B-lymphocytic malignancy. Several examples of this translocation have been cloned, documenting that this abnormality joins the immunoglobulin heavy-chain gene to the bcl-1 locus on chromosome 11. However, the identification of the bcl-1 gene, a putative dominant oncogene, has been elusive. In this work, we have isolated genomic clones covering 120 kb of the bcl-1 locus. Probes from the region of an HpaII-tiny-fragment island identified a candidate bcl-1 gene. cDNAs representing the bcl-1 mRNA were cloned from three cell lines, two with the translocation. The deduced amino acid sequence from these clones showed bcl-1 to be a member of the cyclin gene family. In addition, our analysis of expression of bcl-1 in an extensive panel of human cell lines showed it to be widely expressed except in lymphoid or myeloid lineages. This observation may provide a molecular basis for distinct modes of cell cycle control in different mammalian tissues. Activation of the bcl-1 gene may be oncogenic by directly altering progression through the cell cycle.

Amino Acid Sequence

The effect of air abrasive polishing on blood pH and electrolyte concentrations in healthy mongrel dogs.

The recent re-emergence of air abrasive polishing as an adjunct to professional tooth cleaning has been accompanied by a substantial amount of research. Most of this research has focused on the efficacy of the Prophy-Jet and similar devices in the removal of plaque and stain and on the effects of such devices on restorative materials and the various hard structures of the tooth. Little attention has been paid to the effects of mucosal absorption of the sodium bicarbonate in the polishing abrasive. The purpose of this study was to measure any changes in arterial blood chemistry resulting from the use of the Prophy-Jet. The values for pH, sodium, and bicarbonate, as well as other electrolytes, were measured in 10 dogs over a 2 hour period following a 5 minute timed use of the Prophy-Jet. Of all the parameters examined, only the potassium concentration showed a statistically significant change, and the magnitude of this change was not felt to be clinically significant. The pH and concentrations of sodium and bicarbonate remained essentially unchanged with the use of the Prophy-Jet.

Air

Critical care surgical techniques.

A veterinarian dealing with critical and trauma patients must be proficient with techniques for tracheostomy, thoracostomy tube placement for chest drainage, diagnostic peritoneal lavage, and autotransfusion. The utilization of these techniques may be life-saving in the critical patient. A tracheostomy is indicated in any patient with upper airway obstruction that cannot be managed with supplemental oxygen and/or orotracheal intubation. A tracheostomy tube with an inner cannula is preferred. Tracheostomy tubes should be cleaned at 3- to 4-h intervals, and methods should be employed to decrease thick tracheal secretions and to remove them from the trachea. A patient with a tracheostomy tube should be monitored continuously. A thoracostomy tube is indicated in any patient with large and/or continuous accumulation of air, blood, fluid, or chyle in the pleural space. The thoracostomy tube should be at least the same size as the patient's main stem bronchus. The thoracostomy tube is placed aseptically at the seventh intercostal space at the junction of the upper one third and lower two thirds of the lateral chest wall. Fluid or air may be removed from the chest intermittently with a three-way stopcock attached to the thoracostomy tube and a 60-ml syringe. If continuous drainage is needed, a continuous underwater seal and suction system should be used. Diagnostic abdominal paracentesis and peritoneal lavage are useful techniques in the determination of abdominal trauma, hollow viscus rupture, peritonitis, hepatic trauma, and urinary system trauma. When a multiholed catheter and lavage are used, the accuracy of detecting abdominal trauma is 95 per cent. When only needle paracentesis is used, the accuracy drops to 47 per cent. Abdominal lavage fluid can be analyzed for bacteria, whole blood, white blood cells, free bilirubin, creatinine, blood urea nitrogen, amylase, alkaline phosphatase, and alanine aminotransferase. Large volumes of whole blood recovered from abdominal or thoracic paracentesis can be reinfused into the patient if needed, providing it is not contaminated or markedly hemolyzed. The blood should be collected aseptically into blood bottles or bags. If the bleeding is ongoing or the blood only a few hours old, anticoagulants should be used. If the hemorrhage is several hours old, then clotting and defibrination has already occurred and the blood can be collected into "dry" bags or bottles. Before use, abdominal blood should be analyzed for urine, bile or fecal contamination. Blood collected from the thoracic cavity is much less likely to be contaminated. Autotransfused blood is administered through a standard blood administration set.

Animals

Translocations and rearrangements in T-cell acute leukemias with the t(11;14) (p13;q11) chromosomal translocations.

Chromosomal translocations involving the T-cell receptor alpha and delta genes at q11 on chromosome 14 are the most common cytogenetic abnormalities in patients with T-cell tumors. We have demonstrated that the t(11;14)(p13;q11) translocation in two T-ALL patients involves the J delta region suggesting that the translocation proceeds or coincides with delta gene rearrangement. Additional rearrangements on both normal and translocated chromosomes 14 are described including rearrangement of both Tcr-alpha and Tcr-delta genes, and deletions within the J alpha region. The polyclonality of rearrangements on the normal chromosome 14 in one of the patient samples demonstrates that T-cell receptor rearrangement continues after the translocation event. The identification of clonally expanded rearrangements involving both the Tcr-delta and the Tcr-alpha genes in a single patient suggests a cascade model for delta----alpha expression may be a viable pathway for T-cell maturation.

Base Sequence

Anesthetic and supportive management during experimental pulsatile flow perfusion studies in calves.

The purpose of this study was to determine the factors influencing successful experimental cardiopulmonary bypass studies using pulsatile flow perfusion and the medications and methodology necessary to produce successful bypass in calves. In six calves showing no cardiopulmonary pathology prior to bypass procedures, successful anesthesia and surgical intervention was accomplished. Animals were maintained on 5 hours of pulsatile flow bypass perfusion. Successful recovery from the procedures was accomplished. In two calves with pre-existing pulmonary pathology, anesthetic and surgical intervention was accomplished with the utilization of extensive anesthetic management and cardiac supportive medications until the animals could be initiated into 5 hours of pulsatile flow bypass perfusion, in spite of major pulmonary dysfunction. In these two animals, attempts to resuscitate upon termination of pulsatile flow perfusion were unsuccessful due to pre-existing excessive lesions in the lungs. This study shows a contrast between complete success of a pulsatile flow system in normal subjects versus the ultimate failure in experimental animals with pre-existing pulmonary pathology. The inability of experimental calves with a diseased lung to resume spontaneous cardiopulmonary function after the challenges of thoracic intervention indicates the unsuitability of animals with marked pre-existing pulmonary disease status for use in cardiopulmonary bypass studies.

Anesthesia, General

A common mechanism of chromosomal translocation in T- and B-cell neoplasia.

The chromosomal breakpoint involved in the t(8;14)(q24;q11) chromosome translocation in the SKW-3 cell line, which directly involves the 3' flanking region of the c-myc gene, was cloned and sequenced. The breakpoint on chromosome 8 mapped to a position 3 kb 3' of c-myc while the chromosome 14 breakpoint occurred 36 kb 5' of the gene for the constant region of the alpha chain of the T-cell receptor (TCR). The translocation resulted in a precise rearrangement of sequences on chromosome 8 and what appears to be a functional J alpha segment on chromosome 14. Signal sequences for V-J joining occurred at the breakpoint positions on both chromosomes 14 and 8, suggesting that the translocation occurs during TCR gene rearrangement and that it is catalyzed by the enzymatic systems involved in V-J joining reactions. The involvement of c-myc in the translocation and the association of joining signals at the breakpoints provides a parallel to the situation observed in the translocations involving c-myc and the immunoglobulin loci in B-cell neoplasms and suggests that common mechanisms of translocation and oncogene deregulation are involved in B- and T-cell malignancies.

B-Lymphocytes

A chronic sheep preparation for the study of drug pharmacokinetics in spinal and ventricular CSF.

We describe a sheep preparation utilizing chronic vascular and subarachnoid catheterization and ventriculocisternal perfusion. This preparation allows simultaneous, atraumatic sampling of plasma and CSF after drug administration by the intravenous, intracerebroventricular, or lumbar intrathecal (i.t.) routes in an unanesthesized animal. This sheep preparation provides a convenient means of studying the CSF distribution of exogenous and/or endogenous substances. During intravenous infusion at a rate of 2.2 micrograms/kg/min, morphine appears in cisternal CSF within 15 min. The steady-state plasma concentration and CSF flux (or appearance rate) of morphine was 0.037 and 0.009 micrograms/min, respectively. At steady state, 0.008% of the administered dose appears in CSF/min. The coadministration of morphine, methadone, and [14C]sucrose into the fifth lumbar subarachnoid space is associated with the simultaneous appearance of morphine and [14C]sucrose, but not methadone, in cisternal CSF. The ratio of [14C]sucrose to morphine increased by nearly sevenfold in cisternal CSF, indicating clearance of morphine relative to [14C]sucrose as the compounds ascend in the CSF axis. The simultaneous appearance of morphine and [14C]sucrose in cisternal CSF after lumbar subarachnoid administration indicates that morphine, like sucrose, is distributed within the CSF by bulk flow. This sheep preparation can be used to provide the quantitative data necessary for the development of pharmacokinetic-pharmacodynamic models that relate plasma and CSF concentrations of opiates to their pharmacological effects. These studies will help to provide the pharmacological rationale for the administration of opiates by novel routes for pain management in man.

Animals

Purification of plasminogen activator from Rous sarcoma virus-infected chick embryo fibroblast culture medium.

A new procedure for the purification of plasminogen activator secreted by cultured Rous sarcoma virus-infected chick embryo fibroblasts was described. The enzyme was isolated from culture medium containing 0.75% calf serum depleted of plasminogen by lysine-agarose affinity column chromatography and of high-molecular-weight protease inhibitors by ultracentrifugation. The culture conditions allowed convenient preparation of large amounts of culture fluid with relatively high concentrations of plasminogen activator. The purification of the enzyme was accomplished by affinity chromatography on fibrin-celite and p-aminobenzamidine-agarose columns, and by gel-filtration chromatography in the presence of urea. The activity was recovered in greater than 90% yield, and the enzyme was essentially homogeneous when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Yields from 500 ml culture fluid exceeded 500 micrograms.

Animals