Search PubMed⌕ Search

Biomedical subjects

L A Ross

Publications and source records attributed to L A Ross.

At least 37 records · Page 2Linked to original sources
PubMed1994

Investigation of an epidemic of invasive aspergillosis: utility of molecular typing with the use of random amplified polymorphic DNA probes.

When seven immunocompromised patients developed invasive aspergillosis during construction at a hospital, new methods were performed to compare fungal isolates and a case-control study was conducted to determine risks for infection. Typing of Aspergillus flavus with the use of restriction endonuclease analysis and restriction fragment length polymorphism using random amplified polymorphic DNA reactions to generate DNA probes revealed different patterns between isolates from two patients and a similar pattern among those from one patient, a health care worker, and an environmental source. Case patients were more likely than controls to have longer periods of hospitalization (median, 83 vs. 24 days; P < 0.01), neutropenia (median, 33 vs. 6 days; P < 0.05), and exposure to broad spectrum antimicrobials (median, 56 vs. 15 days; P = 0.08). No patients restricted to protected areas developed aspergillosis. Risk of exposure of immunocompromised patients to opportunistic organisms stirred up by construction activity may be decreased by admitting these patients to protected areas away from construction activity and by restricting traffic from construction sites to these areas. Although typing of A. flavus isolates did not reveal a single type or source of organism responsible for infection, this method may facilitate epidemiologic investigation of possible nosocomial sources and transmission in similar settings.

Adolescent↗
PubMed1993

Epidemic measles in the postvaccine era: evaluation of epidemiology, clinical presentation and complications during an urban outbreak.

A total of 440 cases of measles were seen at a single children's hospital during an epidemic in a large urban center. These cases were retrospectively analyzed for demographic characteristics, exposure histories, risk factors for and incidence of complications, outcome and financial consequences. More than 90% of children were < 5 years of age and 56% were < 15 months of age. Ninety-four percent were of Hispanic or African-American ethnic background. A visit to a medical facility was the only source of infection for 83 of the 115 patients for whom exposure histories were available. Four patients with underlying immunodeficiency were among those nosocomially exposed and one died of pulmonary complications. Of the 440 patients 195 (44.3%) required hospitalization for measles complications. The mean age of hospitalized patients, 1.9 +/- 2.4 years, was not different from those not admitted (2.1 +/- 2.5 years; P < 0.25). The most frequent indications for admission were respiratory tract complications (pneumonia and/or croup) seen in 161 patients and dehydration in 25 patients. Fourteen required intensive care and 11 required intubation and mechanical ventilation. Three children died, all of pulmonary involvement. Total hospital and medical charges for care of these patients was more than $1.7 million dollars.

Adolescent↗
PubMed1992

Clock drawing in the screening assessment of cognitive impairment in an ambulatory care setting: a preliminary report.

In an exploratory study to assess the utility of clock drawing as a screening test for cognitive impairment in medical/surgical outpatients, clock drawing and the 6-item Orientation-Memory-Concentration Test (OMCT) were administered to over 400 randomly selected ambulatory patients over the age of 55 in a busy inner-city hospital. The clock drawing test was completed by 431 patients, and 471 completed the OMCT. Clock drawing errors suggestive of moderate-to-severe cognitive impairment were found in 42.7% of patients; OMCT errors suggestive of moderate-to-severe cognitive impairment were found in 35.4% of the population tested. The clock drawing test might represent a quick-screen for cognitive impairment in an older general medical/surgical outpatient population, and might help identify patients not otherwise recognized as potentially unable to fully understand treatment recommendations.

Aged↗
PubMed1992

Laryngotracheobronchitis as a complication of measles during an urban epidemic.

OBJECTIVE: To evaluate demographic and clinical correlates of laryngotracheobronchitis (LTB) as a complication of measles during a community-wide epidemic. DESIGN: Retrospective review of medical records. SETTING: Childrens Hospital Los Angeles, a large urban pediatric facility, during a regional epidemic of measles studied January through June 1990. PATIENTS: All patients identified at our hospital who met Centers for Disease Control criteria for measles. MEASUREMENTS AND RESULTS: Of 440 patients with measles, 82 also had LTB (18.6%). Patients in whom LTB developed were significantly younger (mean +/- SD: 14.7 +/- 8.2 months) than the cohort (24.8 +/- 30.1 months) (p less than 0.001) and more likely to require hospitalization (91.5%) than the cohort (44.3%) (p less than 0.001). Thirteen patients (17.3%) required intensive care, including 9 (11%) who required endotracheal intubation for a mean of 8.3 +/- 7.1 days. Pulmonary function testing of five patients with an endotracheal tube in place, including three not clinically assessed as having pneumonia, indicated the presence of concomitant lower respiratory tract disease. CONCLUSION: Laryngotracheobronchitis was a frequent and often severe complication of measles. The likelihood that LTB would develop was inversely related to age, generally required inpatient care, and necessitated endotracheal intubation in severely affected patients.

Adolescent↗
PubMed1991

Plasma disappearance of creatinine as a renal function test in the dog.

The serum concentration of creatinine at 120 minutes (SC120) after intravenous injection of 88 mg kg-1 of creatinine, the plasma half-life (t1/2) and the plasma clearance of creatinine (PCC) were evaluated as renal function tests in 30 healthy adult dogs and six adult dogs with known or suspected renal disease. The mean SC120 in the normal dog was 0.31 +/- 0.08 mmol litre-1 and in the clinical cases 0.71 +/- 0.19 mmol litre-1. The correlation coefficients between SC120 and renal creatinine clearance (RCC) for the normal dogs and the clinical cases were -0.76 and -0.69, respectively. At 120 minutes after injection, 95 per cent of normal dogs would be predicted to have a serum creatinine concentration below 0.46 mmol litre-1. The mean plasma t1/2 of creatinine for the normal dogs was 107.7 +/- 17.96 minutes, while the clinical cases had a wide range of values (148.8 to 620.1 minutes). Plasma t1/2 of creatinine was correlated with RCC for both the normal dogs and the clinical cases (r = -0.55, r = -0.91, respectively). The mean PCC for the normal dogs was 7.42 +/- 2.22 ml min-1 kg-1 (range 4.95 to 13.28 ml min-1 kg-1). There was a good correlation between RCC and PCC (r = 0.7). The PCC for the clinical cases ranged from 0.76 to 3.37 ml min-1 kg-1. The correlation between RCC and PCC was significant (r = 0.91). Thus SC120, t1/2 and PCC may be useful methods of assessing renal function in dogs with renal impairment insufficient to cause azotaemia.

Animals↗
PubMed1991

Nosocomial measles infection in a pediatric hospital during a community-wide epidemic.

From Jan. 1, 1988, through Dec. 31, 1988, a total of 89 cases of measles were observed at Childrens Hospital of Los Angeles, and 37 patients were admitted to the hospital. Of the 37 patients, six were not initially thought to have measles, which resulted in exposure of 107 patients and 24 personnel. Of the exposed patients, measles developed in four. One nosocomially infected infant died of pneumonia. Another exposed patient was subsequently admitted to another hospital with unrecognized measles, which led to exposure of an additional eight patients. Of seven employees in whom measles developed, two required hospitalization because of pneumonia. Two hundred eleven employee days were lost because of measles exposure or infection. Infection control interventions included prophylaxis of exposed patients, employee education, and measles immunization for susceptible personnel. Of 1103 hospital personnel considered susceptible to measles, 800 received monovalent measles vaccine. No secondary cases of measles occurred in hospital personnel who received appropriate prophylaxis. We conclude that infection control programs aimed at mandating measles immunity in hospital employees at risk should be instituted.

Age Factors↗
PubMed1991

Imipenem/cilastatin treatment of bacterial meningitis in children.

The safety and efficacy of imipenem/cilastatin were evaluated in 21 children, ages 3 to 48 months, with bacterial meningitis. Eradication of bacteria from the cerebrospinal fluid was demonstrated within 24 hours of antibiotic therapy in all but 2 patients who had Haemophilus influenzae type b meningitis and ultimately achieved bacteriologic cure after 2 to 3 days of imipenem/cilastatin therapy. Cerebrospinal fluid penetrations of imipenem and cilastatin were determined at various times after drug administration with mean cerebrospinal fluid: serum ratios of 14 and 10% for imipenem and cilastatin, respectively. The study was terminated when 7 (33%) patients developed seizure activity after antibiotic therapy was administered. The usefulness of imipenem/cilastatin for the treatment of bacterial meningitis in children may be limited by a possible increased incidence of drug-related seizure activity.

Anti-Bacterial Agents↗
PubMed1991

Interaction of monocytes with cocultures of human aortic wall cells involves interleukins 1 and 6 with marked increases in connexin43 message.

Medium from cocultures of human aortic endothelial cells (HAEC) and smooth muscle cells (HASMC) taken from the same donor contained approximately two- to fourfold more macrophage colony-stimulating factor, granulocyte/macrophage colony-stimulating factor, and up to 5.1-fold more transforming growth factor beta than could be accounted for by the sum of the activities of media from equivalent numbers of HAEC and HASMC cultured separately. After pulse labeling, immunoprecipitated [35S]fibronectin and [14C]collagen were also found to be substantially increased in the coculture compared to the sum of HAEC and HASMC cultured separately. The cocultivation of HAEC and HASMC resulted in a 2.7-fold increase in connexin43 messenger RNA. When direct physical contact between HAEC and HASMC was prevented by a membrane that was permeable to medium, the levels of [35S]fibronectin and [14C]collagen in the coculture were significantly reduced. Monocytes cultured alone contained low levels of [35S]fibronectin and [14C]collagen but when added to the coculture there was up to a 22-fold increase in [35S]fibronectin and a 1.9-fold increase in [14C]collagen compared to the coculture alone. The increase in fibronectin was prevented in the presence of neutralizing antibody to interleukin 1 and antibody to interleukin 6 by 45% and 67%, respectively. Addition of monocytes to cocultures also induced the levels of mRNA for connexin43 by 2.8-fold. We conclude that the interaction of HAEC, HASMC, and monocytes in coculture can result in marked increases in the levels of several biologically important molecules and that increased gap junction formation between the cells and interleukins 1 and 6 may be partially responsible for these changes.

Aorta↗
PubMed1991

Monocyte transmigration induced by modification of low density lipoprotein in cocultures of human aortic wall cells is due to induction of monocyte chemotactic protein 1 synthesis and is abolished by high density lipoprotein.

Incubation of cocultures of human aortic endothelial (HAEC) and smooth muscle cells (HASMC) with LDL in the presence of 5-10% human serum resulted in a 7.2-fold induction of mRNA for monocyte chemotactic protein 1 (MCP-1), a 2.5-fold increase in the levels of MCP-1 protein in the coculture supernatants, and a 7.1-fold increase in the transmigration of monocytes into the subendothelial space of the cocultures. Monocyte migration was inhibited by 91% by antibody to MCP-1. Media collected from the cocultures that had been incubated with LDL induced target endothelial cells (EC) to bind monocyte but not neutrophil-like cells. Media collected from cocultures that had been incubated with LDL-induced monocyte migration into the subendothelial space of other cocultures that had not been exposed to LDL. In contrast, media from separate cultures of EC or smooth muscle cells (SMC) containing equal number of EC or SMC compared to coculture and incubated with the same LDL did not induce monocyte migration when incubated with the target cocultures. High density lipoprotein HDL, when presented to cocultures together with LDL, reduced the increased monocyte transmigration by 91%. Virtually all of the HDL-mediated inhibition was accounted for by the HDL2 subfraction. HDL3 was essentially without effect. Apolipoprotein AI was also ineffective in preventing monocyte transmigration while phosphatidylcholine liposomes were as effective as HDL2 suggesting that lipid components of HDL2 may have been responsible for its action. Preincubating LDL with beta-carotene or with alpha-tocopherol did not reduce monocyte migration. However, pretreatment of LDL with probucol or pretreatment of the cocultures with probucol, beta-carotene, or alpha-tocopherol before the addition of LDL prevented the LDL-induced monocyte transmigration. Addition of HDL or probucol to LDL after the exposure to cocultures did not prevent the modified LDL from inducing monocyte transmigration in fresh cocultures. We conclude that cocultures of human aortic cells can modify LDL even in the presence of serum, resulting in the induction of MCP-1, and that HDL and antioxidants prevent the LDL induced monocyte transmigration.

Antioxidants↗
PubMed1991

Caregiver's anticipatory grief in dementia: a pilot study.

Twenty-seven wives who care for their spouses suffering from dementia completed the Anticipatory Grief Scale (AGS) and the Hopkins Symptom Checklist--SCL-90-R. The alpha coefficient for the AGS was 0.84, indicating good internal consistency. The AGS was also positively and significantly correlated (p less than 0.001) with the depression, anxiety, and hostility dimensions of the SCL-90-R, demonstrating good validity. The study explores bereavement issues of spouses of patients with dementia and provides preliminary findings on a new instrument to measure anticipatory grief.

Aged↗
PubMed1990

Reduction of hydronephrosis and hydroureter associated with ectopic ureters in two dogs after ureterovesical anastomosis.

Severe hydronephrosis and hydroureter associated with ectopic ureters were diagnosed in 2 dogs. Surgical transplantation of the ectopic ureters into the urinary bladder resulted in urinary continence in both dogs. Intravenous urography revealed a marked decrease in the size of hydronephrosis and hydroureter in both dogs 28 to 35 weeks after surgery. In 1 dog with bilateral ureteral ectopia, kidney size and renal function remained normal for 5 years after surgery. A dog with one ectopic ureter and an associated ureterocele had a marked reduction in size of the affected kidney and an apparent decrease in function of that kidney, as indicated by decreased opacification on an intravenous urogram.

Anastomosis, Surgical↗
PubMed1990

Immunogenicity of Haemophilus influenzae type B vaccines in children with hepatoportoenterostomies.

To assess the immunogenicity of HIB vaccines in patients in whom hepatoportoenterostomies were performed for biliary atresia, eight such children received Haemophilus influenzae type b-polyribosylribitol phosphate (HIB-PRP) vaccine and had pre- and postvaccination total serum anti-PRP antibody concentrations determined by radioimmunoassay. Preimmunization anti-PRP antibody levels ranged from less than 0.125 to 0.40 microgram/ml [geometric mean antibody titer (GMT) 0.106 microgram/ml], while postvaccination levels ranged from 0.161 to 1.192 micrograms/ml (GMT = 0.489 microgram/ml). Five children who did not achieve postimmunization anti-PRP antibody levels greater than 1.0 microgram/ml received 15 micrograms of either PRP coupled to diphtheria toxoid (PRP-D) or PRP coupled to an outer membrane protein complex of Neisseria meningitidis group B (PRP-NOMP) conjugate vaccine. Anti-PRP antibody levels 1 month after immunization with HIB conjugate vaccines ranged from 1.51 to 10.35 micrograms/ml (GMT = 3.386 micrograms/ml). Patients with extrahepatic biliary atresia and hepatoportoenterostomies who previously received the HIB-PRP vaccine should be revaccinated with PRP protein conjugate vaccines to ensure adequate protection against H. influenzae type b disease.

Antibody Formation↗
PubMed1989

Fluid therapy for acute and chronic renal failure.

Animals with renal failure have a number of fairly predictable metabolic abnormalities. They are commonly presented to the veterinarian in a state of negative water balance, although prior fluid therapy in an oliguric patient may result in overhydration. Animals with oliguric ARF have sodium retention; those with polyuric ARF have increased urinary sodium loss. Chronic renal failure does not necessarily affect the ability of the renal tubule to conserve or excrete sodium, although the response to changes in sodium load is much slower than in the normal animal. Potassium retention occurs in oliguric ARF and potassium wasting in polyuric ARF; potassium balance is approximately normal in animals with CRF. Both ARF and CRF cause metabolic acidosis, although the acid-base status in a given animal will be affected by respiratory compensation, as well as other problems such as vomiting. Calcium levels are usually normal to slightly decreased in renal failure, whereas phosphorus levels are generally increased. The basic principles of fluid therapy should be used when constructing a plan for such therapy in an animal with renal failure. Intravenous administration of fluids is almost always necessary. The choice of the type of fluid, solutes, and electrolytes to be administered is based on the predicted abnormalities associated with renal failure as well as the laboratory abnormalities in the animal. Careful monitoring of the patient and periodic assessment of various laboratory parameters are necessary in order to make appropriate adjustments in fluid therapy.

Acute Kidney Injury↗