Soon-Jae Hwang

A giant pyogenic granuloma in the nasal cavity caused by nasal packing

Abstract Pyogenic granuloma is a benign, rapidly growing hemorrhagic lesion of unknown origin. This disorder, however, is obscure to many rhinologists, because the nose is a relatively rare location for the lesion. In the practice of otorhinolaryngology, nasal packing is a very common procedure for nasal bleeding and postoperative hemostasis. However, few pyogenic granulomas occurring from nasal packing have been reported in the literature. A 56-year-old man underwent nasal packing with vaseline gauze because of nasal bleeding. Two months later, a dark brown nasal tumor was found in his nasal cavity. He underwent endoscopic endonasal removal of the tumor. The pathology result showed a pyogenic granuloma. This is the third case recorded in the literature of a confirmed pyogenic granuloma occuring as a complication of nasal packing. This uncommon lesion should be considered in the differential diagnosis of a rapidly growing hemorrhagic lesion within the nasal fossa.

A molecular epidemiologic study of methicillin-resistant Staphylococcus aureus infection in patients undergoing middle ear surgery

Abstract The incidence of methicillin-resistant Staphylococcus aureus (MRSA) infections after middle ear surgery has recently increased at our hospital. Most of these infections were thought to be hospital-acquired when medical personnel in contact with an MRSA-infected patient may have inadvertently transmitted the pathogen to other patients. To prevent further transmission it is essential that such sources of MRSA infection and transmission routes be selected out and eradicated. Therefore, it is necessary to determine whether the strains of MRSA isolated from infected patients are identical to those obtained from medical personnel in order to prove a reciprocal transmission of organisms between medical personnel and patients. Surveillance bacterial cultures from the anterior nares and hands of medical personnel working in the Department of Otolaryngology, Korea University Guro Hospital, were performed at two different time points: 6 December 1994 and 17 June 1996. Ribotyping with Southern blot technique was used to compare 12 MRSA strains from medical carriers with 60 strains identified from the otorrhea of MRSA-infected patients undergoing middle ear surgery. As result, six different MRSA strains were identified (types I, II, III, IV, V and VI) from ribotyping with EcoR1. One distinct subtype, type I strain, was the most frequently identified strain in both medical carriers and patients. Results also showed that 6 MRSA isolates from 10 medical carriers and 20 from 30 patients contained type I ribotype at first culture. Two medical carriers’ isolates and 13 isolates from 30 patients shared the same type I strain at the second surveillance culture. In all, 41 out of 72 MRSA strains (56.9%) shared an identical ribotype pattern. Postoperative MRSA infection rates after treatment of medical carriers and the application of rigorous preventive procedures decreased from 11.9 to 5.7% after first culture and 9.0 to 7.7% following second cultures. These findings confirm that MRSA transmission can occur between medical personnel and patients and that effective preventive measures can reduce the postoperative infection rate.

Expression of secretory leukocyte protease inhibitor in middle ear cholesteatoma

Secretory leukocyte protease inhibitor (SLPI) is a cationic protein and a member of the innate immunity-associated protein family. The main function of SLPI is to protect local tissue against the detrimental consequences of inflammation. We undertook this study to investigate the expression of SLPI in human middle ear cholesteatoma tissue as compared with normal external auditory canal skin. Cholesteatoma tissues and external auditory canal skin samples were obtained from eight patients during middle ear surgery. The expression levels of SLPI mRNA and protein were evaluated by real-time reverse transcription-polymerase chain reaction (RT-PCR) and western blotting. Immunohistochemical staining was performed in both tissue groups using anti-SLPI antibody. Real-time RT-PCR showed that SLPI mRNA levels in cholesteatoma tissues were increased 7.8-fold on average as compared with normal auditory canal skin. Western blotting analysis showed that SLPI protein expression in cholesteatoma epithelium is up-regulated versus external auditory canal skin epithelium. Immunohistochemical staining for SLPI showed that SLPI is expressed mainly in the stratum granulosum and in subepithelial inflammatory cells. These findings imply that SLPI contributes to host protection against inflammatory cell and destructive enzymes in the chronic inflammatory state of cholesteatoma by affecting the innate immune system.

Protective role of superoxide dismutase in rat eustachian tubal mucosa against acute otitis media induced by upper respiratory tract infection

Superoxide dismutase has been known to play a role as an anti-oxidative system against oxidative injury during acute inflammation. To investigate the role of superoxide dismutase in eustachian tubal mucosa during acute otitis media (AOM), an animal model was made. Sprague-Dawley rats were inoculated with Streptococcus pneumoniae through the nasal cavity following development of virus-induced upper respiratory infection. The animals were divided into three groups according to their tympanic cavity conditions following bacterial inoculation; inoculated animals with no resultant AOM (no-AOM), animals with resultant AOM (AOM) and animals with resolving otitis media (recovery). The changes of superoxide dismutase in each tubal mucosa were compared with that of the normal control using immunohistochemistry and immunoblotting methods. On Western blot, there were little changes of optical density and surface area in no-AOM (213.5 +/- 22.4, 13.2 +/- 0.8 mm2) and recovery group (219.3 +/- 18.7, 14.8 +/- 0.7 mm2) compared to the normal control (223.5 +/- 26.2, 16.7 +/- 0.4 mm2). However, a marked decrease was found in the AOM model (167.6 +/- 19.3, 6.5 +/- 0.9 mm2). These findings suggest that superoxide dismutase may play a role in protecting tubal mucosa from free radical injury during AOM.

Possibility of reciprocal infection of methicillin-resistant Staphylococcus aureus between medical personnel and patients undergoing middle ear surgery

The incidence of methicillin-resistant Staphylococcus aureus (MRSA) infection after middle ear surgery has recently increased in our hospital. In this study we tried to determine whether the strains of MRSA isolated from infected patients are identical to those obtained from medical personnel, to prove a reciprocal transmission between medical personnel and patients. Surveillance bacterial cultures of medical personnel were performed from the anterior nares and from the fingertip. Molecular epidemiological studies, ribotyping and pulsed-field gel electrophoresis (PFGE) were used to compare the 12 MRSA strains obtained from carriers among medical personnel with the 60 strains identified from patient’s otorrhea. Six different MRSA strains were identified from ribotyping, and three subtypes from PFGE. There was a particular subtype which was the most frequently identified strain found in both medical carriers and patients. Postoperative MRSA infection rates after the treatment of medical carriers and application of preventive procedures decreased from 11.9 to 5.7%. These findings suggest that the MRSA transmissions have occurred between medical personnel and patients.

Expression of Neutrophil Gelatinase—Associated Lipocalin in Human Salivary Glands:

Objectives: We performed an observational study of RNA and protein expression in human tissue to examine the distribution of neutrophil gelatinase–associated lipocalin (NGAL) in normal and chronic inflammatory salivary tissues, and to investigate the expression level of NGAL in inflammatory conditions of salivary glands. Methods: Normal salivary gland tissues and tissue samples of salivary glands with chronic sialadenitis were obtained. Expression of NGAL was investigated by reverse transcriptase–polymerase chain reaction, and semiquantitative analysis of these results was also performed. The differential localization and amount of immunoreactivity to NGAL protein was evaluated by immunohistochemistry and Western blot analysis in normal salivary gland tissues and salivary glands with chronic sialadenitis. Results: NGAL messenger RNA transcripts were detected in the tissues from the salivary glands with chronic sialadenitis, but only a small amount was detected in the tissues from the normal salivary glands. A weak expression of NGAL protein was occasionally seen in a few ductal epithelial cells of normal salivary gland tissue. However, in tissue samples from glands with chronic sialadenitis, the NGAL protein was expressed strongly in ductal epithelial cells and infiltrating inflammatory cells. Conclusions: These results imply that NGAL is associated with the regulation of inflammation in salivary glands.

Expression of Oncostatin M in Chronic Obstructive Sialadenitis of the Submandibular Gland

Objectives: We investigated the expression of oncostatin M messenger RNA (mRNA) and protein in normal submandibular glands and those with chronic obstructive sialadenitis and localized the expression of o costatin M protein. Methods: Submandibular glands from 10 patients with chronic obstructive sialadenitis as a study group and 10 normal submandibular glands as a control group were examined. Oncostatin M mRNA extracted from submandibular gland was used for reverse transcription–polymerase chain reaction and analyzed semiquantitatively. The difference in expression level of oncostatin M protein between the 2 groups was analyzed through Western blot analysis, and oncostatin M protein was localized immunohistochemically. Results: The expression levels of oncostatin M mRNA and protein were significantly increased in the study group. The protein was predominantly localized in ductal epithelia and infiltrating inflammatory cells and was more strongly expressed in the study group also. Conclusions: Oncostatin M is expressed in both chronic obstructive sialadenitis and normal submandibular gland, and is up-regulated in chronic obstructive sialadenitis. These results suggest that oncostatin M is involved in the pathologic process of chronic obstructive sialadenitis. However, the physiologic role in normal glands, as well as a possible role in the development of chronic obstructive sialadenitis, remains to be elucidated.