Biomedical subjects
Publications and source records attributed to B H Hamory.
Staphylococcus epidermidis is an organism formerly believed to be nonpathogenic. It is now recognized as a pathogen, causing infections on implanted devices and among immunosuppressed patients. Further, it has been involved in the development of resistance to a number of antibiotics. The epidemiology of this organism, its pathogenesis, and its treatment are important to infection control practitioners.
Explore the source record for details and available documents.
A simplified method for the isolation, identification, and characterization of Staphylococcus epidermidis from humans is described. Swabs of the nose and skin are cultured on mannitol salt agar. Isolated colonies not producing acid from mannitol (presumptive coagulase-negative staphylococci or micrococci) are then inoculated onto purple agar containing erythromycin and glycerol. All colonies growing on this medium are then replicated onto media that tests for the production of phosphatase, the production of acid from trehalose, and susceptibility to four antibiotics. All S. epidermidis sensu stricto are confirmed by the API Staph-Ident system. As a result, Staphylococcus aureus and all other coagulase-negative staphylococci are effectively identified and eliminated from further study and only strains of S. epidermidis are left for further characterization. Of the 252 isolates from 48 cultures of the nares and the fingers, 112 (44%) were eliminated during different stages of this isolation and identification procedure. The antibiotic susceptibility data further distinguished those isolates in the predominant API biochemical profile number. This scheme has applications in the early stages of either ecologic or epidemiologic studies of this important nosocomial pathogen.
Sepsis due to methicillin-resistant Staphylococcus epidermidis occurred in a neutropenic man during management with a Hickman-Broviac catheter. Despite catheter removal and 10 days of i.v. cefazolin therapy, he developed septic arthritis 6 weeks later in a nonprosthetic hip joint. S. epidermidis was isolated from the joint and found to have plasmid and phage susceptibility patterns identical to the previous blood isolate. This case is the first to document a metastatic infection from catheter-associated S. epidermidis bacteremia. It suggests that cephalosporins may not be optimal in such infections despite in vitro sensitivity. Vancomycin appears to be the drug of choice for S. epidermidis bacteremia in the neutropenic population.
Explore the source record for details and available documents.
Current technique for determining cardiac output involves multiple manipulations of the injectate system and thereby raises the potential for serious infection. A randomized crossover study was undertaken to compare three methods for determining cardiac outputs, focusing on (1) ability to maintain sterile injectate, (2) operator time, and (3) cost effectiveness. The methods compared were the closed-loop injectate delivery, capped-syringe, and double-bag systems. Forty-five subjects were randomly assigned to one of three methods used, then "crossed over" to an alternate method. This resulted in six different groups: (1) 15 subjects assigned to closed loop first, then crossed over to double bag (eight) or capped syringe (seven), (2) 15 subjects assigned to double bag first, then crossed over to closed loop (seven) or capped syringe (eight), and (3) 15 subjects assigned to capped syringe first, then crossed over to double bag (seven) or closed loop (eight). Quantitative cultures of sample injectates served as indicators of contamination. The Wilcoxon signed rank analysis showed no statistical difference (p greater than 0.9) in patient or catheter characteristics between treatment groups. None of 30 cultures from the closed-loop method yielded bacterial growth, compared to 6 of the 30 cultures positive from each of the other methods (p less than 0.0001). The closed-loop method also required less operator time and was more cost effective than the two alternate methods examined.
Explore the source record for details and available documents.
Three consecutive patients undergoing automated peritoneal dialysis developed peritonitis with a nonfermenting gram-negative rod. The same organism was recovered from the dialysate produced by the machine and from its tap water supply. This is the first such outbreak in which the causative organism was also recovered from the tap water supply to the machine. The organism persisted in the machine following standard 3% formaldehyde disinfection, but was eradicated by 10% formaldehyde disinfection.
A survey of 1429 university hospital employees was conducted to estimate the extent of unreported needlestick injuries. Data based on 726 responses show that 40% of needlestick injuries within the past 3 months and 75% of needlestick injuries in the previous year had not been reported. Employees who did not report needlestick injuries were more likely to be new employees (less than 2 years). In addition to nursing, laboratory, and housekeeping employees, inhalation therapists and pharmacists are also at high risk for needlestick injuries. Studies attempting to show a reduction in needlestick injury rate should not use employee health records to assess efficacy.
We report two cases of orf, a common viral disease of sheep, which occurred in residents of Missouri. A survey taken among sheep raisers in Missouri revealed that many were unaware of this as a potential human disease. It is important for physicians to be able to recognize this lesion so that radical methods of therapy are not employed. The lesion heals without scarring and without specific therapy. Complications are rare.
We have reviewed 58 cases of bone marrow granuloma at a single institution over a 20-year time span, and have summarized the available English literature. We conclude that bone marrow granulomas are an infrequent pathologic finding which, when found, require definition as to an underlying etiology. Undoubtedly, the illnesses associated with marrow granuloma are similar to those causing granulomatous hepatitis. The following additional statements may justifiably be made based on this review. There are no morphologic features which allow reliable differentiation between the causes of bone marrow granuloma. By combining careful histologic, microbiologic, and serologic techniques, an etiology can be documented in most (87%) patients with marrow granulomas. A medication history is an important element of this evaluation. Rocky Mountain spotted fever, cytomegalovirus infection, ibuprofen, acute lymphocytic leukemia, and various collagen vascular diseases should be added to the list of causes of marrow granuloma. The prognostic significance of marrow granuloma in patients without an ascertainable underlying illness remains unclear.
Explore the source record for details and available documents.
Despite technical advances, Foley catheter associated urinary tract infections continue to be the leading cause of nosocomial infections. PVP-I2 has been shown to be nonirritating to abraded tissue and we have shown that dilute solutions are bactericidal for organisms causing Foley catheter associated urinary tract infections. The purpose of this study was to ascertain the toxicity of PVP-I2 on the catheterized rat bladder and to measure the systemic absorption of I2. Bladder catheters were surgically placed into each of 3 groups of rats: group 1, catheters only; group 2, irrigation with PBS q.8h; and group 3, irrigation with a 1:3 dilution of a 10 per cent PVP-1 per cent I2 solution q-8h. One-half of each group was sacrificed at 1 and 2 weeks respectively. Photographs of mounted bladders and histologic sections were then graded by 3 independent observers. Blood for protein bound iodine (PBI), T3 and T4 levels was obtained before the study and at sacrifice. No difference in ulcerations, erythema or inflammation was noted. PBI was higher in group 3 rats at conclusion than group 1 and 2 (6.88 mg./dl. versus 3.42 mg./dl.) (p less than 0.05). There was no difference in T3 or T4 levels. In this study, PVP-I2 was no more toxic to the bladder than catheterization alone or irrigation with PBS.
Explore the source record for details and available documents.
Spinal cord syndromes with a mainly syringomyelic pattern of sensory diorders, radiculopathies, mixed paresis of varying degree (without any history of trauma), have been found in 507 out of 1305 new patients referred to out Clinic from January 1976 till 31 October 1977. In 105 randomised and unselected cases with these syndromes, myelographies have disclosed findings compatible with an adhesive spinal and/or cisternal arachnoiditis. A prospective study of the syndromes for evidence of infectious aetiology has been performed, in which tuberculosis, syphilis and other infections appear to be causative agents. A randomised therapeutic trial on a limited number of cases has been evaluated, as well as the results of specific therapy in a larger number of cases. Results of treatment have not been satisfactory. Operations were performed on only five patients and in no case was an autopsy obtained. Spinal cord syndromes due to non-traumatic adhesive arachnoiditis are discussed. The possible pathogenetic mechanisms the predominantly syringomyelic sensory deficits in those syndromes are briefly mentioned.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Eighty-one adults with symptoms of acute sinusitis were studied by direct needle puncture and aspiration of the maxillary sinus (105 sinuses). Fifty-nine bacterial strains were isolated in titers of greater than or equal to 10(4) colony-forming units/ml; Streptococcus pneumoniae and Haemophilus influenzae accounted for 64% of the isolates. Other bacteria recovered included anaerobes (12%), Neisseria species (8.5%). Streptococcus pyogenes (3%), alpha-hemolytic Streptococcus (3%), non-group A beta-hemolytic Streptococcus (3%), Staphylococcus aureus (2%), Pseudomonas aeruginosa (2%), and Escherichia coli (2%). Viruses were isolated from 11 sinuses; these isolates included rhinovirus (six), influenza A (H3N2) virus (three), and two types of parainfluenza virus (one each). The efficacy of therapy with orally administered ampicillin, amoxicillin, or trimethoprim-sulfamethoxazole was evaluated by a repeat sinus puncture and culture. Clinical and bacteriologic responses to all three regimens were good.