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Biomedical subjects

L Bland

Publications and source records attributed to L Bland.

13 recordsLinked to original sources
PubMed1997

An outbreak of Enterobacter hormaechei infection and colonization in an intensive care nursery.

Enterobacter hormaechei was first identified as a unique species in 1989. Between 29 November 1992 and 17 March 1993, an outbreak of E. hormaechei occurred among premature infants in the intensive care nursery (ICN) at The Hospital of the University of Pennsylvania. The 10 infants whose cultures were positive for E. hormaechei (six were infected and four were colonized) had a lower median estimated gestational age and birth weight than did other ICN infants; other risk factors for infection or colonization with E. hormaechei were not identified. Cultures from three isolettes and a doorknob in the ICN were positive for E. hormaechei. Pulsed-field gel electrophoresis of isolates from six patients and two isolettes were identical. Observations of health care workers revealed breaks in infection control techniques that may have allowed transmission of this organism. We found that E. hormaechei is a nosocomial pathogen that can infect vulnerable hospitalized patients and that can be transmitted from patient to patient when infection control techniques are inadequate.

Disease Outbreaks↗
PubMed1996

Neutrophil and cytokine activation with neonatal extracorporeal membrane oxygenation.

OBJECTIVE: To determine whether extracorporeal membrane oxygenation (ECMO), like cardiopulmonary bypass, produces systemic inflammatory responses that could potentiate organ injury in infants with respiratory failure. STUDY DESIGN: We evaluated the effects of neonatal ECMO on neutrophil surface adherence proteins, elastase release, and cytokine levels in blood samples from 15 patients before and during ECMO, and from banked blood and ECMO circuit blood before cannulation. Neutrophil elastase, tumor necrosis factor alpha, and interleukin types 1 beta, 6, and 8 were measured. Chest radiographs were evaluated by a radiologist using a lung injury score in blinded fashion. RESULTS: Primed ECMO circuit blood, in comparison with patient pre-ECMO blood, demonstrated marked up-regulation of CD11b (mean fluorescence intensity 1660 +/- 109 vs 361 +/- 81; p < 0.001 (mean +/- SEM)), shedding of L-selectin (mean fluorescence intensity 10 +/- 2 vs 89 +/- 38; p < 0.01), and elevated elastase levels (349 +/- 76 vs 154 ng/ml +/- 38; p < 0.001), consistent with neutrophil activation. During ECMO, neutrophil CD11b levels increased but L-selectin was not significantly shed. Concentrations of circulating neutrophil elastase increase significantly during ECMO. Corrected circulating quantities of interleukin-8 also rose significantly, but the responses of tumor necrosis factor alpha and interleukin-1 beta were minimal. Radiographic lung injury scores worsened with the initiation of ECMO (median score: 6 before ECMO vs 11 in first hour of ECMO; p = 0.012), in conjunction with indicators of neutrophil activation. CONCLUSION: Neonates with respiratory failure have activation of the inflammatory cascade. ECMO incites additional neutrophil and cytokine activation in association with early pulmonary deterioration. Routine leukodepletion of blood for circuit priming to remove activated neutrophils may be beneficial.

Cytokines↗
PubMed1995

Bloodstream infections associated with a needleless intravenous infusion system in patients receiving home infusion therapy.

OBJECTIVE: To determine risk factors for bloodstream infections (BSIs) in an outbreak among patients receiving home intravenous infusion therapy. DESIGN: Case-control and retrospective cohort studies. SETTING: Home health agency. PATIENTS: Patients receiving home intravenous infusion therapy from Rhode Island Home Therapeutics (RIHT) from January through December 1993. MAIN OUTCOME MEASURE: Development of primary BSI. METHODS: We compared patients with BSI (ie, case patients) with randomly selected noninfected RIHT patients receiving intravenous therapy, conducted a cohort study of all RIHT patients receiving intravenous therapy via a central venous catheter (CVC), and conducted a culture survey of injection cap luminal fluid. RESULTS: Case patients were more likely than controls to have had therapy via a CVC (11/11 vs 14/32; odds ratio [OR] undefined; P < .001) or total parenteral nutrition and intralipid therapy (TPN/IL) (9/11 vs 3/32; OR, 43.5; 95% confidence interval [CI], 4.9 to 510.0). Among RIHT patients with CVCs, risk factors for BSI were receipt of TPN/IL (9/35 vs 2/67; rate ratio [RR], 8.6; 95% CI, 2.0 to 37.7) or use of a needleless infusion system (10/41 vs 1/61; RR, 14.9; 95% CI, 2.0 to 111.8). Only the combination of both exposures was significantly associated with development of a BSI (P < .001). Luminal fluid from injection caps of needleless devices was significantly more likely to be culture positive than fluid from protected-needle devices (5/23 vs 0/18; RR undefined; P = .04). CONCLUSIONS: Our data suggest that a needleless device used for TPN/IL was associated with increased risk of BSI when injection caps were changed every 7 days.

Case-Control Studies↗
PubMed1995

Transmission of HIV in dialysis centre.

In August, 1993, 13 dialysis patients at one dialysis centre in Colombia, South America, were found to be HIV positive, and this prompted an epidemiological investigation. We carried out a cohort study of all dialysis centre patients during January, 1992 to December, 1993 (epidemic period) to determine risk factors for HIV seroconversion. Haemodialysis and medical records were reviewed, dialysis centre staff and surviving patients were interviewed, and dialysis practices were observed. Stored sera from all dialysis centre patients were tested for HIV antibody. 12 (52%) of 23 patients tested positive for HIV antibody by enzyme immunoassay and western blot during the epidemic period. Of the 23 tested, 9 (39%) converted from HIV antibody negative to positive (seroconverters) and 10 (44%) remained HIV negative (seronegatives). The HIV seroconversion rate was higher among patients dialysed at the centre while a new patient, who was HIV seropositive, was dialysed there (90% vs 0%; p < 0.01), or when the dialysis centre reprocessed access needles, dialysers, and bloodlines (60% vs 0%). While 2 of 9 HIV seroconverters had had sex with prostitutes, none had received unscreened blood products or had other HIV risk factors. No surgical or dental procedures were associated with HIV seroconversion. Dialysers were reprocessed separately with 5% formaldehyde and were labelled for use on the same patient. Access needles were reprocessed by soaking them in a common container with a low-level disinfectant, benzalkonium chloride; 4 pairs of needles were placed in one pan creating the potential for cross-contamination or use of one patient's needles on another patient. HIV transmission at the dialysis centre was confirmed. Improperly reprocessed patient-care equipment, most probably access needles, is the likely mechanism of transmission. This outbreak was discovered by accident and similar transmission may be occurring in many other countries where low-level disinfectants are used to sterilise critical patient-care equipment.

Adult↗
PubMed1994

Mycobacterium abscessus pseudoinfection traced to an automated endoscope washer: utility of epidemiologic and laboratory investigation.

After 15 patients had positive cultures for Mycobacterium abscessus without evidence of infection (i.e., pseudoinfection) following endoscopy, retrospective cohort studies of patients undergoing endoscopy and microbiologic sampling of the environment were done to examine potential nosocomial transmission and to identify the source and risk factors for M. abscessus pseudoinfection. In the epidemic period, M. abscessus-positive cultures were significantly more likely to be obtained during bronchoscopy than gastroendoscopy (16/149 vs. 1/860, P < .001) and during procedures using bronchoscopes disinfected in an automated washer rather than by other methods (16/54 vs. 0/95, P < .001). M. abscessus was recovered from the automated washer, the inlet water feeding the washer, and a flexible bronchoscope. Environmental and case-patient isolates had identical large restriction fragment (LRF) patterns of genomic DNA separated by pulsed-field gel electrophoresis. Molecular typing using LRF analysis supported the epidemiologic results and demonstrate the utility of combined epidemiologic and laboratory investigations in nosocomial outbreaks of nontuberculous mycobacteria.

Adult↗
PubMed1993

Otoacoustic emissions as a cross-check in pediatric hearing assessment: case report.

Audiologic assessment of infants and young children can be confounded by neurologic disorders or neuromaturational delays. In some cases, this results in an inability to assess hearing sensitivity by behavioral measures or by auditory evoked potentials. This case illustrates such an audiologic challenge. Subject DF was born with hydrocephaly, which was treated with repeated shunt surgeries and resulted in seizures and pervasive developmental delays. At 9 months of age, the child was tested by auditory brainstem response (ABR) measurement and found to have no response to sound. Believing that her child had hearing, DF's mother sought a second opinion. Results of an audiologic evaluation at 11 months of age showed no measurable behavioral responses in the sound field and an ABR abnormality that prevented prediction of hearing sensitivity. In contrast, sensitivity prediction by the acoustic reflex and results of both transient-evoked and distortion-product otoacoustic emissions predicted normal peripheral hearing sensitivity. This case illustrates the usefulness of otoacoustic emissions as an additional cross-check measure in pediatric hearing assessment.

Cochlea↗
PubMed1991

A minority perspective in the diagnosis of child language disorders.

The effective diagnosis and treatment of persons from diverse minority language backgrounds has become an important issue in the field of speech and language pathology. Yet, many SLPs have had little or no formal training in minority language, there is a paucity of normative data on language acquisition in minority groups, and there are few standardized speech and language tests appropriate for these groups. We described a diagnostic process that addresses these problems. The diagnostic protocol we have proposed for a child from a Black English-speaking background characterizes many of the major issues in treating minority children. In summary, we proposed four assessment strategies: gathering referral source data; making direct observations; using standardized tests of non-speech and language behavior (cognition, perception, motor, etc.); and eliciting language samples and probes.

Black or African American↗
PubMed1988

Protein serotyping of Streptococcus pneumoniae based on reactivity to six monoclonal antibodies.

Six monoclonal antibodies to proteins of Streptococcus pneumoniae were tested in a dot blot assay for reactivity with 499 clinical isolates of pneumococci. Forty-four percent of the isolates reacted with at least one of the antibodies. Nineteen patterns of reactivity were identified and each designated as a provisional protein serotype. Protein serotyping identified pneumococcal strains independently of their capsular type and made it possible to differentiate strains within most capsular types. A protein serotyping system provides a new dimension to the phenotypic identification of S. pneumoniae and may eventually provide a basis for assessing the population structure of these organisms.

Animals↗
PubMed1985

Hypertensive response to saline microinjection in the area of the nucleus tractus solitarii of the rat.

We investigated the blood pressure response elicited by microinjection of various hypertonic solutions into the area of the nucleus tractus solitarii (NTS) of the brainstem, an area rich in catecholaminergic neurons. Equiosmolar solutions of NaCl, dextrose, LiCl and KCl were employed. NaCl produced a prolonged blood pressure rise; LiCl and normal saline produced a similar rise of short duration; and KCl produced epileptic-type seizures with postictal hypertension. Dextrose had no effect and neither had NaCl microinjection in areas relatively distant from the NTS. The rise in blood pressure was not reversed by a vasopressin antagonist injected systemically, but was totally abolished by systemic alpha-adrenergic blockade with phentolamine. These findings suggest that sodium can cause hypertension by direct stimulation of the central sympathetic nervous system without participation of peripheral mechanisms such as fluid volume expansion or alteration of the vascular wall.

Animals↗
PubMed1985

Hemodialyzer reuse: practices in the United States and implication for infection control.

Reuse of hemodialyzers has continued to increase dramatically. In 1983, 52% of the hemodialysis centers were reusing hemodialyzers. Use of hollow fiber hemodialyzers has paralleled this increase in hemodialyzer reuse with 63% of the hemodialysis centers reporting exclusive use of this type of hemodialyzer in 1983. Although reuse of hemodialyzers has not been associated with increased incidence of hepatitis B infection or pyrogenic reactions, an outbreak of nontuberculous mycobacteria in 27 chronic hemodialysis patients was probably associated with water used to reprocess dialyzers. Nontuberculous mycobacteria were isolated from the water in 83% of 115 hemodialysis centers surveyed across the United States and could constitute a potential infection risk because of the organisms' greater germicide resistance than most other naturally occurring water bacteria. Two percent formaldehyde is not an effective germicide for high level disinfection of hemodialyzers. Reprocessed hemodialyzers should be disinfected with 4% formaldehyde or an equivalent disinfectant.

Hepatitis B↗
PubMedDate not supplied

Decrease in cerebral blood flow in rats after experimental subarachnoid hemorrhage: a new animal model.

There continues to be a need for good animal models of experimental subarachnoid hemorrhage (SAH). The rat would be an ideal subject in which to study SAH since it is inexpensive and easier to use than the larger laboratory animals. The present study was undertaken to determine if alterations of cerebral blood flow could be produced in the rat after experimental SAH, and thereby justify using the rat as a model for further study of SAH. Rats weighing between 450 and 500 grams underwent insertion of a cannula into the cisterna magna at least 5 days prior to physiological testing. One group of rats then received a 0.3 cc injection of fresh autologous arterial blood into the cisterna magna to simulate a SAH. Another group of rats received injection of an equal volume of mock CSF (buffered saline) into the cisterna magna. A third group of rats had no subarachnoid injections. In all three groups, blood flow to the cerebral hemispheres was measured with the labeled microsphere technique. Rats with experimental SAH showed a 40% decrease of cerebral blood flow, whereas rats with saline injections showed only a 15% decrease. Control rats had no changes of cerebral blood flow. These studies demonstrate that the rat is a potential experimental model for investigations into SAH.

Animals↗