Aeration selects for mucoid phenotype of Pseudomonas aeruginosa.

A mucoid strain of Pseudomonas aeruginosa isolated from a patient with cystic fibrosis and its nonmucoid revertant were grown in a chemically defined alginate-promoting medium under batch and continuous culture conditions. Selection for the mucoid and nonmucoid phenotype was accomplished by varying the levels of air available to the culture. The addition of air at a rate of 0.5 liters/min to the nonmucoid revertant growing under batch or continuous culture conditions resulted in a greater than 50% decrease in viability over a 10-h incubation period. In contrast, aeration of the mucoid culture maintained a totally mucoid population and there was no decrease in viability over a 55-h incubation. Aeration of a mixed population of the mucoid and nonmucoid phenotype (1:1) resulted in selection for the mucoid phenotype within the first 20 h of cocultivation. The correlation between the mucoid phenotype and alginic acid was demonstrated by the production of 580 micrograms of uronic acid per mg (dry weight) of cells by the mucoid phenotype and less than 1 microgram of uronic acid per mg (dry weight) of cells by the nonmucoid revertant. These results suggest that nonmucoid revertants may have an unusual sensitivity to aeration, which may indicate a mechanism for natural selection of the mucoid phenotype in vivo.     

Urban adolescents' perceptions of their neighborhoods: An examination of spatial dependence

Spatial dependence exists when the variation between observations is dependent on spatial location. In the present study, geostatistical methods were used to examine spatial dependence in adolescents' perceptions of their neighborhoods: whether adolescents living in close proximity perceived their neighborhoods more similarly than adolescents living further apart. Participants included 343 adolescents (53% male; 91% African American) enrolled in sixth grade, residing in Baltimore City, with geocoded home addresses. These addresses were used in combination with a measure of perceived neighborhood disorder and disadvantage to compute variogram plots, a geostatistical technique used to evaluate spatial dependence. Results indicated that perceptions of youth residing in close geographic proximity were more similar than perceptions of youth residing further apart. Adjusting for census‐level characteristics, but not individual and family characteristics, resulted in decreased variation among participants but did not eliminate the spatial dependence. Findings highlight the utility of geostatistical methods for social science research. © 2004 Wiley Periodicals, Inc. J Comm Psychol 32: 277–293, 2004.     

Chest pain with normal coronary arteries: a comparative study of psychiatric and social morbidity

Ninety-nine patients with chest pain and a presumptive diagnosis of coronary heart disease were assessed blindly within 24 hours of angiography, using standardized psychiatric and social interviews and a personality inventory. Thirty-one patients had normal coronary arteries (NCA), 15 had slight disease and 53 had significant coronary obstruction. Twenty-eight (61%) of the 46 patients with insignificant disease and 12 (23%) of the 53 with significant obstruction had psychiatric morbidity. Associations between the overall severity of psychiatric morbidity and measures of social maladjustment were strongest in the patients with normal coronary arteries. The 26 men with insignificant coronary artery disease had higher scores of neuroticism and extraversion than the 41 with important coronary occlusions. No differences were observed when the same comparisons were made for the women. The findings indicate that approximately two thirds of patients with normal and near-normal coronary arteries have predominantly psychiatric rather than cardiac disorders: the symptoms in these patients are more likely to represent the somatic manifestations of anxiety and overbreathing than the consequences of underlying cardiac disease. Physicians should be aware of the ways in which neurotic illness may present with symptoms mimicking cardiac disease, especially when cardiovascular symptoms are accompanied by phobic symptoms and unexplained shortness of breath.     

More training needed in chronic care: a survey of US physicians.

PURPOSE: Although more than 125 million North Americans have one or more chronic conditions, medical training may not adequately prepare physicians to care for them. The authors evaluated physicians' perceptions of the adequacy of their chronic illness care training to and the effects of training on their attitudes toward care of persons with chronic conditions. METHOD: In November 2000 through June 2001, the authors surveyed by telephone a random sample of U.S. physicians who had > or =20 hours of patient contact per week. The interview instrument examined demographics, career satisfaction, practice characteristics, perceived adequacy of chronic illness care training in ten competencies (geriatric syndromes, chronic pain, nutrition, developmental milestones, end-of-life care, psychosocial issues, patient education, assessment of caregiver needs, coordination of services, and interdisciplinary teamwork), and effect of training on attitudes toward chronic illness care. RESULTS: Of 1,905 eligible physicians, 1,236 (65%) responded (270 family or general practitioners, 231 internists, 129 pediatricians, 335 nonsurgical specialists, and 271 surgeons). Most physicians reported their chronic disease training was less than adequate for all ten competencies. Family practitioners were more likely (p <.05) to report adequate training in seven competencies compared with internists, and in two to four competencies when compared with pediatricians, nonsurgical specialists, or surgeons. Most physicians reported that training had a positive effect on attitudes toward care of people with chronic conditions, including the ability to make a difference in their lives (74-84%). CONCLUSIONS: Physicians perceived their medical training for chronic illness care was inadequate. Medical schools and residencies may need to modify curricula to better prepare physicians to treat the growing number of people with chronic conditions.     

Cationization of bovine serum albumin alters its conformation as well as its charge

The molecular charge on bovine serum albumin (BSA) was modified by substituting carboxyl groups on the protein with ethylenediamine, thereby producing a highly cationic derivative with a pI of 9.3 to 9.5. Gel-filtration studies showed that the molecular weight of BSA was not significantly altered after cationization. When the cationized BSA was administered to rabbits using a chronic serum sickness schedule of injections, the animals developed a membranous glomerulopathy similar to the human disease, except that approximately one-third of the animals also showed focal and segmental endocapillary proliferation. Comparison of the circular dichroism spectra of native and cationized BSA showed that the substitution of the carboxyl groups resulted in a 50% reduction in the alpha-helical content of the native molecule. This conformational change should be considered as a possible determinant of the different immune response and immunopathology associated with the cationized molecule compared with native BSA.     

Endocytosis of horseradish peroxidase-poly-lysine conjugate by glomerular epithelial cells: an in vivo study

Native horseradish peroxidase (HRP) is known to pass rapidly through glomeruli when injected into rats. We have found that a conjugate of HRP with poly-lysine is readily endocytosed by glomerular epithelial cells (GEC). We have used this conjugate to study the GEC endocytotic process in male Wistar rats. The conjugate has an approximate molecular weight of 55-58,000, a pI of greater than 10.0, and almost the same secondary conformation as HRP; it does not increase urinary protein excretion significantly or alter the morphology of the renal glomeruli. After intravenous injection of the conjugate, it could be found in the GBM from 1 min to 4 h. At 1 min, it was evenly distributed on GEC foot processes and plasma membrane. GEC start to take up the conjugate from 1 min post-injection, by cellular membrane invagination. This reached a maximum at 4 h. Some of the endocytosed conjugate passed to lysosomes from the endosomal system. The amount of peroxidase demonstrable in the glomerular epithelial cells was considerably reduced by 24 h.     

Lobular carcinoma with cytoplasmic granules

We report on a case of invasive lobular carcinoma of the breast with a previously undescribed cytologic feature. Diff-Quik-stained cytologic preparations showed uniform single cells with prominent coarse cytoplasmic granules. Ultrastructurally, the granules showed features suggestive of autophagosomes and/or degenerative mitochondria. The cytologic differential diagnosis included granulocytic sarcoma, metastatic melanoma, extramedullary hematopoiesis, large granulocytic leukemia/lymphoma, and mast-cell tumor. Adjunctive studies were helpful in the diagnosis of carcinoma. Histologic study of the mastectomy specimen showed classic type of invasive lobular carcinoma.     

Use of the fascial stapler® in proctopexy for rectal prolapse

Proctopexy using synthetic mesh is a popular method of treating rectal prolapse. Suturing the graft to the presacral fascia is time-consuming and can lead to complications. With the fascial staper^®, two parallel rows of three staples are used to quickly and securely anchor the Marlex sling to the sacrum, thus avoiding hemorrhage from the presacral veins. Fourteen patients have been treated with no complications.     

Hyperbaric oxygen therapy in chronic stable multiple sclerosis: double-blind study

We carried out a randomized, double-blind, placebo-controlled trial of hyperbaric oxygen therapy (HBO) in patients with chronic stable MS. Eighty-two patients were treated in a multiplace hyperbaric chamber with gas supplied by mask. Forty-one patients received 20 consecutive daily treatments of 100% O2 followed by 7 "booster" treatments in the next 6 months; 41 control patients received "air" (12.5% O2 at 1.75 atmospheres absolute). There was no significant difference in treatment and control groups in the Extended Kurtzke Disability scores, Kurtzke Functional scores, magnetic resonance imaging, or evoked potentials after the initial 20 treatments or after the boosters. HBO is not effective in treating chronic stable MS.     

Multifocal CT enhancement in MS

Review of 146 CTs in 125 MS patients showed that 53.4% (39/73) of those done during acute relapse showed enhancing lesions. Of scans done during the "active" stage of disease, 40.8% (20/49) showed enhancement, whereas only 12.5% (3/24) showed enhancement during clinically inactive periods. Autopsy confirmation that enhancing lesions represent demyelinating plaques was obtained in one patient. This study shows that enhancing lesions in MS reflect biologic activity and are most likely to be seen during acute clinically apparent relapses. More than one-half of the patients hospitalized with acute attacks appeared to be having multifocal relapses. These findings show that acute relapses are commonly multifocal and suggest that they are mediated by blood-borne factors.