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Biomedical subjects

A B Kressel

Publications and source records attributed to A B Kressel.

7 recordsLinked to original sources
PubMed2001

Pseudo-outbreak of Mycobacterium chelonae and Methylobacterium mesophilicum caused by contamination of an automated endoscopy washer.

OBJECTIVE: To evaluate an unusual number of rapidly growing acid-fast bacilli, later identified as Mycobacterium chelonae, and pink bacteria, later identified as Methylobacterium mesophilicum, from fungal cultures obtained by bronchoscopy. DESIGN: Outbreak investigation. SETTING: An academic medical center performing approximately 500 bronchoscopies and 4,000 gastrointestinal endoscopies in 1998. PATIENTS: Patients undergoing bronchoscopy July 21 to October 2, 1998. METHODS: The infection control department reviewed patient charts and bronchoscopy logs; obtained cultures of source water, faucets, washers, unopened glutaraldehyde, glutaraldehyde from the washers, and endoscopes; observed endoscope and bronchoscope cleaning and disinfecting procedures; reviewed glutaraldehyde monitoring records; and sent M. chelonae isolates for DNA fingerprinting. RESULTS: M. chelonae, M. mesophilicum, gram-negative bacteria, and various molds grew from endoscopes, automated washers, and glutaraldehyde from the washers but not from unopened glutaraldehyde. The endoscopy unit regularly monitored the pH of glutaraldehyde, and the logs contained no deficiencies. The above sources remained positive for the same organisms after a glutaraldehyde cleaning cycle of the automated washers. DNA finger-printing of the M. chelonae revealed that they were clonally related. CONCLUSIONS: The automated washers were contaminated with a biofilm that rendered them resistant to decontamination. The washers then contaminated the endoscopes and bronchoscopes they were used to disinfect. Our institution purchased new endoscopes and a new paracetic acid sterilization system.

Academic Medical Centers↗
PubMed1999

Cryptococcosis in children with AIDS.

We compiled the clinical and immunologic features of Cryptococcus neoformans infections in human immunodeficiency virus (HIV)-infected children from 1985 to 1996 in a retrospective case series. Thirty cases of cryptococcosis were identified. These children had a median age of 9.8 years, a median CD4+ cell count of 54/microL at the time of diagnosis, and either a culture positive for C. neoformans or cryptococcal antigen in serum or cerebrospinal fluid. Sixty-three percent of the cases occurred in children vertically infected with HIV and in children between 6 and 12 years of age. The clinical and laboratory characteristics of this pediatric cohort were similar to those of adults with AIDS and cryptococcosis. On the basis of a subset of the cases, a 10-year point prevalence of cryptococcosis among children with AIDS of approximately 1% was estimated.

AIDS-Related Opportunistic Infections↗
PubMed1995

Analysis of human monoclonal antibodies elicited by vaccination with a Cryptococcus neoformans glucuronoxylomannan capsular polysaccharide vaccine.

The Cryptococcus neoformans capsular polysaccharide glucuronoxylomannan (GXM) has been conjugated to tetanus toxoid (GXM-TT) as an investigational vaccine. GXM-TT elicits antibodies that are protective in C. neoformans-infected mice. In an effort to characterize the fine specificity and molecular structure of human GXM-TT-elicited antibodies, we generated two GXM monoclonal antibodies (MAbs) from peripheral blood lymphocytes of a volunteer GXM-TT recipient and studied serum GXM antibody idiotype expression in 10 additional vaccinees. The MAbs, 2E9 and 3B6, are the immunoglobulin M(lambda) isotype and bind capsular polysaccharides of C. neoformans serotypes other than the serotype A that was used for immunization. Neither antibody competes with murine GXM MAbs for antigen binding, suggesting that the human MAbs recognize a different epitope. The B-cell superantigen staphylococcal protein A binds both MAbs, and human immunodeficiency virus gp120 binds 2E9. MAb nucleic acid sequence analysis revealed that both antibodies use an identical V lambda 1a-J lambda genetic element with different, somatically mutated, members of the VH3 gene family and different DH and JH gene elements. The gene elements used by both MAbs occur in fetal B-lymphocyte repertoires, autoantibodies, and other polysaccharide antibodies. Post-GXM-TT vaccination GXM antibodies from 10 additional vaccinees expressed a shared idiotype defined by rabbit antiserum raised against MAb 2E9. Our data suggest that the human GXM antibody response is restricted and raise questions regarding the importance of specific variable-region elements and superantigens in the generation of human antibody responses to encapsulated pathogens.

Amino Acid Sequence↗
PubMed1988

Albino spatial vision as an instance of arrested visual development.

Adult albinos and human infants share a number of common visual characteristics: both have low grating acuity, both lack a foveal pit (foveal hypoplasia), and both have much lower central cone densities than in the normal adult. We have explored the consequences of these characteristics by measuring both spatial and temporal contrast sensitivity in the central retina and by comparing central and peripheral grating and vernier acuities in two young adult albino subjects. To compensate for nystagmus, horizontally oriented patterns were employed. Both subjects had normal flicker sensitivities, but their central grating and vernier acuities were approximately five times worse than normal. At 10.0 degrees in the inferior visual field, however, vernier and grating acuities were normal for both subjects. Finally, the ratio of grating to vernier acuity in albino central vision fell within the normal foveal range, suggesting that albino central vision does not resemble the adult periphery. These results are consistent with the hypothesis that spatial processing deficiencies in albino central vision are a direct consequence of the increased spacing of their central cones. Our data are comparable to available psychophysical results obtained from infants of approx. 10 months of age, thus suggesting that the albino visual system may represent a case of arrested development.

Adult↗
PubMedDate not supplied

A comprehensive educational approach to improving patient isolation practice.

OBJECTIVE: To describe a workable plan for the successful education of a large, diverse group of healthcare workers in a university hospital setting. DESIGN: A prospective, nonrandomized study of compliance with infection control isolation practice following various educational interventions. SETTING: 300-bed tertiary-care, academic medical center with out-patient clinics. PARTICIPANTS: Hospital employees and contract workers. INTERVENTIONS: The infection control department introduced a plan to implement the Centers for Disease Control and Prevention's new isolation guidelines. A comprehensive proposal was presented to administration. It included a time line for institution and a comprehensive educational and performance-improvement plan, including standard lectures and a video that explained Standard and Transmission-Based Precautions. Follow-up consisted of customized in-services and one-on-one continued education tailored to the individual units. RESULTS: Compliance with isolation procedure after standardized lectures and video alone was poor. Compliance improved after institution of smaller, more intensive in-services tailored to individual departments and given during all shifts. CONCLUSIONS: Intensive, individualized education is the key to compliance. This requires sufficient infection control staffing and administrative support.

Academic Medical Centers↗