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Biomedical subjects

J C Johnson

Publications and source records attributed to J C Johnson.

At least 109 records · Page 6Linked to original sources
PubMed1991

Amantadine-related adverse reactions among African-American elderly nursing home residents.

To identify factors associated with the development of adverse reactions to amantadine prophylaxis for influenza in a predominantly African-American nursing home population, we retrospectively reviewed the records of 100 residents who did and 45 who did not receive amantadine. During the 4 weeks of amantadine treatment, three independent observers rated all new symptoms as either related or unrelated to amantadine. Two types of comparison were made. Among patients receiving amantadine, those who did or did not develop new symptoms believed to be related to amantadine were compared by age, underlying diagnoses, type and number of medications, and renal function. Similar comparisons were made between patients who did and those who did not receive amantadine. The 100 residents who received amantadine prophylaxis had significantly more nonspecific symptoms than the 45 who did not receive amantadine. Otherwise, the two groups were comparable with regard to age, renal function, number of diagnoses, and medications. Of the 100 residents given amantadine, 16% were judged to experience amantadine-related adverse reactions. Those developing amantadine-related symptoms were significantly more likely to have nonspecific symptoms and to use psychotropic medications.

Aged↗
PubMed1990

Effect of host cell on the in vitro characteristics expressed by two bovine viral diarrhea virus strains.

Growth curves, immunofluorescence assays and radioimmunoprecipitation analysis of bovine viral diarrhea virus (BVDV)-specified polypeptides were used to determine the susceptibility of bovine endothelial cells (BECs) to infection with strains of BVDV. One strain of the virus, NY1, normally non-cytopathic when grown in bovine turbinate cells (BTUs), did not parallel this type behavior in BECs. Virus replication kinetics, morphological changes in infected cells and resolution of viral polypeptides suggest that NY1 replicated and showed cytopathologic changes in infected BECs similar to a cytopathic strain of BVDV, strain C24V. Two previously unreported viral polypeptides were identified in NY1-infected endothelial cells. These polypeptides had molecular weights of 92,000 (92kDa) and 72kDa. These findings suggest that BVDV-cell interactions occurring in BECs differ from those observed in similarly infected BTUs.

Animals↗
PubMed1990

A suture "retractor": a technical aid for bucket-handle meniscal resections.

Meniscal repair, healing, and survival have been demonstrated in the literature. Meniscal preservation is, however, not always possible. We present a technique that may aid the surgeon in difficult bucket handle resections by stabilizing a portion of the meniscus with a "suture retractor" prior to resecting either a posterior or anterior meniscal horn. This technique may also be modified to prepare the inner rim when one is performing meniscal repair.

Humans↗
PubMed1990

Using DSM-III criteria to diagnose delirium in elderly general medical patients.

Studies of delirium in general medical populations have used criteria for delirium different from current DSM-III or DSM-IIIR criteria of the American Psychiatric Association, or have used DSM-III or DSM-IIIR criteria without operationalizing the components of these criteria. Therefore this prospective study was conducted to establish an approach to operationalizing DSM-III criteria and to determine the incidence and prevalence of delirium. Two hundred thirty-five consecutive subjects age 70 and over admitted to general medicine underwent daily standardized screening. Patients with low scores on screening tests or clinical evidence suggestive of any psychiatric disorder and controls were seen by a psychiatrist, who determined whether delirium was present by applying explicit operational definitions to each component of the DSM-III criteria for delirium. We conclude that the syndrome of delirium as defined by the American Psychiatric Association is prevalent on admission among elderly on general medical services, but the number of cases developing in the hospital is much less than often stated in the literature.

Aged↗
PubMed1990

Effects of bovine somatotropin on milk yield and composition, body weight, and condition score of Holstein and Jersey cows.

Forty cows (20 Holstein, 20 Jersey) were administered 0, 5, 10, 15, or 20 mg of recombinantly derived bST daily to determine the effect on milk yield, milk composition, body weight, and body condition score. Administration of bST was from 75 +/- 7 d through 305 d postpartum. A total mixed diet of 45% corn silage and 55% of a concentrate mixture (dry basis) was provided for ad libitum intake. Milk yield of Holstein and Jersey cows administered 20 mg of bST increased 25.3 and 22.8%, respectively, over controls. Fat-corrected milk from Holsteins and Jerseys that were administered 20 mg of somatotropin increased 32.2 and 18.7% over controls, but Jersey response was greatest when 15 mg of bST were administered (27.1% over controls). Dry matter intake of the 20 mg bST group was 13.5% greater than DM intake of controls. Apparent efficiency of production increased linearly with increasing somatotropin. There was no significant change in body weight, but body condition score declined linearly with increasing somatotropin. Most milk composition measures were unaffected by somatotropin. Jersey and Holstein milk yield increased quadratically and linearly, respectively, with somatotropin dose.

Analysis of Variance↗
PubMed1990

Effects of bovine somatotropin on dry matter intake, milk yield and body temperature in Holstein and Jersey cows during heat stress.

Thirty-one lactating Holstein and Jersey cows were used to determine the effect of daily injections of 0 or 20 mg of recombinant bST in hot, humid weather. The comparison period lasted 80 d, from mid-June through August. The maximum and minimum ambient temperature and relative humidity averaged 34.6 and 22.2 degrees C and 100 and 59.8%, respectively. Body temperatures of somatotropin-treated Holsteins were elevated over controls by .2 and .3 degrees C at the a.m. and p.m. milkings, respectively, whereas corresponding treatment effects for Jerseys were .5 and .6 degrees C, thus demonstrating a breed by treatment interaction. The response of milk and FCM yields and apparent efficiency of production to somatotropin administration depended on the level of production prior to treatment. Cows at low pretreatment production increased milk and FCM yields to a greater degree than did cows at higher production. A breed by treatment interaction showed that Holsteins increased milk and FCM yields more than Jerseys upon administration of somatotropin. Intake of DM was not affected by treatment. Cows administered bST lost BW and condition score. Greater heat stress was associated with the higher milk production of cows administered bST.

Animals↗
PubMed1990

Delirium in the elderly.

Delirium, an acute confusional state, is an organic brain syndrome that manifests deficits in attention, irrelevant or rambling speech, and other cognitive deficits. Its symptoms often fluctuate over the course of the day, and patients may be hyperactive--for example, restless and screaming--or hypoactive--for example, quiet, inactive, and stuporous. Occurring in approximately 20% of hospitalized elderly patients, delirium is the most common psychiatric syndrome in acutely ill general medical and surgical patients. Fifteen to 30% of delirious patients expire, and others are prone to a variety of complications: falls, pressure ulcers, oversedation, dehydration, and others. Almost any acute illness can cause delirium in the elderly, but the most common offenders are acute infections and drugs. Many patients have a pre-existing dementia. The first step in arriving at a correct diagnosis is to distinguish delirium from other psychiatric syndromes that can cause confusion, such as dementia, depression, schizophrenia, and mania. Once delirium is established, a comprehensive general examination and a mental status examination is required. Routine laboratory and radiologic tests are directed at the common metabolic and infectious disorders that precipitate delirium. Treatment is directed at the underlying acute illness. In all patients, it is important (1) to treat the underlying acute illness, (2) to provide appropriate fluid and electrolytes, (3) to discontinue any unnecessary drugs, and (4) to allay the patient's fear and agitation through the use of simple, repetitive instructions, orientation cues, and by limiting the use of physical restraints. If psychotropic medications are needed to treat psychotic symptoms, to prevent patients from harming themselves or others, or to facilitate necessary diagnostic and therapeutic interventions, then haloperidol is the drug of choice in most instances. Drugs with anticholinergic properties should be avoided.

Aged↗
PubMed1989

Radiation dosimetry in specific area radiography.

An improved head-and-neck phantom was constructed from a human skull, cervical vertebrae, and Mix D, a mixture of wax, plastic, and metal oxides with x-ray absorbing and scattering properties similar to water and soft tissues. Lithium fluoride thermoluminescent dosimeters were calibrated and then exposed within the phantom. The doses at 17 anatomic sites were calculated for each of the 18 specific area radiographs in a complete intraoral radiographic survey.

Bone Marrow↗
PubMed1989

Esophageal tracheal combitube (ETC) for emergency intubation: anatomical evaluation of ETC placement by radiography.

The esophageal tracheal combitube (ETC) is designed for emergency intubation. The ETC is inserted blindly allowing ventilation after either esophageal or endotracheal placement. A special pharyngeal balloon serves to seal the upper airways. In 10 cardiac arrest patients, emergency intubation with the ETC was performed. Blood gas analyses showed adequate ventilation. Radiography proved correct placement of the proximal and distal balloons in accordance with design theory. Hyperinflation experiments documented expansion of the proximal balloon into the oral cavity rather than towards the epiglottis.

Emergencies↗
PubMed1988

Surgical assessment in the elderly.

Elderly patients face a mortality risk two to three times greater for certain surgical procedures than do middle-aged patients. This increased risk is attributed partly to the normal physiologic changes associated with aging, but more so to pathologic changes seen less uniformly in the elderly population. Most studies report cardiac and pulmonary complications as major adverse consequences. In order to identify and determine the significant risk factors to elderly patients requiring surgery, a comprehensive preoperative evaluation should be performed.

Aged↗
PubMed1987

Optic disc cupping as clinically estimated from photographs.

Cup-to-disc ratios of 204 right eyes were evaluated by two clinicians and by a trained grader using a standardized grading scheme. Mean measurements by the grader were greater than estimates made by either clinician. The measurement scheme used by the trained grader has a high degree of reliability and validity. The standard protocol provides an objective assessment of optic disc cupping and could be easily adapted for office use.

Diabetic Retinopathy↗
PubMed1987

Effects of resuscitation from hemorrhagic shock on cerebral hemodynamics in the presence of an intracranial mass.

This study compares intracranial pressure, cerebral blood flow, and cerebral oxygen transport during hemorrhagic shock and following fluid resuscitation with crystalloid or colloid solution in a canine model with an epidural mass lesion. After placement of an epidural balloon, intracranial pressure was increased to 30 mm Hg for 5 minutes and then permitted to vary without further manipulation. Hemorrhagic shock was produced by the rapid removal of blood to achieve a mean arterial pressure of 55 mm Hg for 30 minutes. Resuscitation then was performed with intravenous lactated Ringer's solution, 60 ml/kg, or with 6.0% hetastarch, 20 ml/kg. Following both solutions mean arterial pressure and cardiac output were increased and hemoglobin concentration was reduced. Intracranial pressure was significantly lower immediately after resuscitation in the hetastarch group; it then gradually increased so that the difference was much less 1 hour later. Cerebral blood flow decreased during shock and was not restored by either fluid; cerebral oxygen transport fell further with resuscitation in both groups due to hemodilutional reductions in hemoglobin. Although colloid resuscitation improved systemic hemodynamics and maintained lower intracranial pressure, it failed, as did crystalloid resuscitation, to restore cerebral oxygen transport to prehemorrhagic shock levels.

Animals↗
PubMed1987

Synergistic inhibition of anatid herpesvirus replication by acyclovir and phosphonocompounds.

Plaque reduction assays were used to evaluate the inhibitory effects of acyclovir (ACV), phosphonoacetate (PAA), and phosphonoformate (PFA) with a plaque-purified isolate of anatid herpesvirus (AHV-ppc3). A plaque assay employing a liquid overlay medium was developed to facilitate the drug inhibition studies. From dose-response curves, the ID50 for PAA, PFA, and ACV were 20, 12, and 0.14 micrograms/ml, respectively. From data obtained from combination dose-response curves, dose isobolograms were prepared and used to determine the types of interactions between drug pairs. Whereas the interaction between PFA and PAA was additive, synergism occurred with ACV and either PAA or PFA. Drug-resistant mutants of AHV-ppc3 resistant to 8.0 micrograms/ml ACV, 250 micrograms/ml PAA, 180 micrograms/ml PFA or 6.0 micrograms/ml AHV, and 220 micrograms/ml PAA were isolated.

Acyclovir↗
PubMed1987

Perioperative care in cancer surgery.

This article reviews the current data on mortality rates of elderly patients undergoing major thoracic and abdominal surgery, those procedures most applicable to cancer surgery. The major morbidity of surgery is discussed in relation to normal aging physiology of the heart, lungs, and kidneys. Preoperative risk assessment is discussed in relation to clinical assessment, laboratory and radiologic assessment, and the use of indexes developed to estimate surgical risk. General recommendations important in the perioperative period are given as well as specific recommendations for patients with cardiac disease, cerebrovascular disease, hypertension, thromboembolic disease, diabetes mellitus, and renal disease.

Aged↗
PubMed1987

Sub-toxic effects of Bacillus sphaericus 1593 M on feeding growth and reproduction of Laccotrephes griseus (Hemiptera: Nepidae).

Long-term effects of sub-lethal doses of biocide (25, 50, 100 and 200 micrograms/ml) from B. sphaericus 1593 M on feeding, growth and reproduction of L. griseus were studied. The deleterous effects of the biocide include: reduced feeding, retarded growth, delayed maturity, reduction in fecundity, and decrease in protein content of the ovary. The effects are convincingly dependent on biocide dose and exposure duration. Extensive use of the biocide may bring a population depletion of non-target species even at sub-lethal concentrations. The possible mode of action of biocide is discussed.

Animals↗
PubMed1986

Xylosylation and glucuronosylation reactions in rat liver Golgi apparatus and endoplasmic reticulum.

We have studied in rat liver the subcellular sites and topography of xylosylation and galactosylation reactions occurring in the biosynthesis of the D-glucuronic acid-galactose-galactose-D-xylose linkage region of proteoglycans and of glucuronosylation reactions involved in both glycosaminoglycan biosynthesis and bile acid and bilirubin conjugation. The specific translocation rate of UDP-xylose into sealed, "right-side-out" vesicles from the Golgi apparatus was 2-5-fold higher than into sealed right-side-out vesicles from the rough endoplasmic reticulum (RER). Using the above vesicle preparations, we only detected endogenous acceptors for xylosylation in the Golgi apparatus-rich fraction. The specific activity of xylosyltransferase (using silk fibroin as exogenous acceptor) was 50-100-fold higher in Golgi apparatus membranes than in those from the RER. Previous studies had shown that UDP-galactose is translocated solely into vesicles from the Golgi apparatus. In these studies, we found the specific activity of galactosyltransferase I to be 40-140-fold higher in membranes from the Golgi apparatus than in those from the RER. The specific translocation rate of UDP-D-glucuronic acid into vesicles from the Golgi apparatus was 10-fold higher than into those from the RER, whereas the specific activity of glucuronosyltransferase (using chondroitin nonasaccharide as exogenous acceptor) was 12-30-fold higher in Golgi apparatus membranes than in those from the RER. Together, the above results strongly suggest that, in rat liver, the biosynthesis of the above-described proteoglycan linkage region occurs in the Golgi apparatus. The specific activity of glucuronosyltransferase, using bile acids and bilirubin as exogenous acceptor, was 10-25-fold higher in RER membranes than those from the Golgi apparatus. This suggests that transport of UDP-D-glucuronic acid into the RER lumen is not required for such reactions.

Animals↗