Biomedical subjects
S R Hoffman
Publications and source records attributed to S R Hoffman.
Occupational exposure to Helicobacter pylori for the endoscopy professional: a sera epidemiological study.
OBJECTIVES: The purpose of this prospective study was to determine if medical and nursing staff in the United States who are regularly involved in endoscopic procedures are at an increased risk of acquiring Helicobacter pylori infection. METHODS: One hundred and twenty-two gastroendoscopists and endoscopy nurses attending an advanced gastroendoscopy course (17 women, 105 men) completed a questionnaire consisting of past medical and professional history. Serum from each subject was collected and tested using a validated ELISA assay (sensitivity 99%, specificity 96%). H. pylori prevalence in the experimental group was compared to that of 510 blood donors. RESULTS: In all age groups, H. pylori positivity was significantly higher among the study subjects compared with controls. Caucasian subjects, when matched to controls for age, race, and level of education, had significantly higher rates of H. pylori positivity. Foreign-born subjects, when compared to US-born subjects, also had higher rates of H. pylori positivity. There was no statistical difference of H. pylori positivity with respect to gender, years involved in endoscopy, or number of endoscopies performed monthly. CONCLUSION: H. pylori infection is more common in gastroendoscopists and endoscopy nurses than the general population and should be viewed as an occupational hazard.
Metronidazole susceptibility testing for Helicobacter pylori: comparison of disk, broth, and agar dilution methods and their clinical relevance.
Since the methods for metronidazole susceptibility testing of Helicobacter pylori have not been standardized or validated, we compared three methods that are used to test the metronidazole susceptibilities of 25 isolates of H. pylori. Specifically, we examined the methods of Steer's replicator agar dilution, tube broth microdilution, and modified Kirby-Bauer disk diffusion. The metronidazole disk zone sizes obtained by the disk diffusion method correlated well (r = 0.74) with the MICs obtained by the agar dilution method. Afterward, the disk diffusion method was used to characterize the metronidazole susceptibilities of 44 isolates of H. pylori. Dual therapy (bismuth and metronidazole) proved to be highly effective against metronidazole-susceptible strains (81.6% eradication rate) but fared poorly against resistant strains (16.7% eradication rate; P < 0.01). Using agar dilution testing, we validated the modified Kirby-Bauer disk diffusion method for metronidazole susceptibility testing of H. pylori and conclude that it is practical, accurate, and clinically applicable.
The Automatic Patient Symptom Monitor (APSM): a voice mail system for clinical research.
Double-blind clinical trials become very tedious when symptoms are measured rather than objective laboratory and physical parameters. The standard "diary card" method is labor intensive for patients and impractical to use for more than a few weeks. In chronic relapsing disorders it would be far better for patients to record symptoms one or more times per day, at defined times, for weeks, months or even years. The Automatic Patient Symptom Monitor (APSM) is a voice processing system designed to achieve this goal. APSM calls patients at home every night, addresses each patient by name and then asks a set of questions which patients answer by pressing the touch tone keys on their telephone. APSM enters data into a computer database file which can be easily retrieved by investigators, even by modem. In a pilot study, patients with telephones easily learned how to use APSM. They were given therapy for a gastric infection (H.pylori) and were monitored by APSM until follow-up one month after completing treatment. Eight of nine patients recorded valid data on > 80% of study days. In all cases, APSM data matched the patient's own impression of whether they were better, the same, or worse. With one exception, APSM assessment correlated with microbiologic data obtained post therapy i.e. when the gastric infection had been eradicated, patients felt better (p < 0.047). Long term clinical monitoring with APSM may decrease clinical trial time and improve the statistical power of double blind studies.
Symptom relief after endoscopic sinus surgery: an outcomes-based study.
Previous studies of patients outcomes after sinus surgery have generally described only a summary measure of overall change in symptoms or health status. This paper describes an outcomes-based longitudinal study of sinus symptom prevalence among thirty-one patients treated with endoscopic surgery for chronic sinusitis. Patients completed structured data collection forms to quantify the prevalence of commonly experienced sinus-related symptoms during an eight-week period both before surgery and six months after undergoing sinus surgery. Significant decreases in nasal symptom prevalence (post-surgery versus pre-surgery) were noted for headaches, nasal drainage, nasal congestion, sinus infection, and breathing difficulties. In addition, the proportion of subjects who rated their current health as "better" compared to one year previously increased from 27% pre-surgery to 58% six months after sinus surgery. These findings aid in quantifying the magnitude of improvement experienced by sinus surgery patients and provide further evidence that endoscopic sinus surgery represents an effective treatment for chronic sinusitis.
Results of endoscopic sinus surgery.
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A 20-minute breath test for helicobacter pylori.
In this study, we evaluated a simplified rapid 14C-urea breath test for the diagnosis of Helicobacter pylori. Fasting patients undergoing initial assessment for H. pylori drank 5 microCi of 14C-urea in 20 ml of water. Breath was collected at intervals for 30 min. Samples were counted in a beta-counter, and the results were expressed as counts per minute (cpm). In the same week, patients underwent endoscopy, and a blinded investigator examined biopsy samples of gastric mucosa by culture and histology for H. pylori. There were 49 H. pylori-negative (HP-) and 104 H. pylori-positive (HP+) patients in the study. HP+ patients expired a mean of 4398 cpm (SD 2468) per mmol CO2 in a sample taken 20 min after ingestion of the isotope. In contrast, HP--patients expired only 340 cpm (SD 196). If the mean +3 SD of HP- patients was used as a cutoff value, the 20-minute sample gave a sensitivity of 97% and a specificity of 100% for detecting H. pylori. The radiation exposure from this test is less than 1% of that received from an upper gastrointestinal series, and the short collection time makes it both convenient and cost effective.
Sinus disease and surgical treatment: a results oriented quality assurance study.
The efficacy of sinus surgery continues to be an issue of debate among otolaryngologists. In an attempt to address this controversy, a case-series study design was used to assess the perceived efficacy of sinus surgery in terms of the alleviation of sinus symptoms and overall health benefit. Self-administered questionnaires were mailed to 142 individuals who had sinus surgery performed between January 1984, and December 1985. After one follow-up attempt, 114 questionnaires were completed and returned (80% response). Overall, a high percentage of cases reported postoperative improvement in breathing difficulties (90%), nasal congestion (88%), headache/facial pain (85%), recurrent sinus infections (83%), and postnasal drip (80%). In addition, 88% of cases reported the surgery to be of some overall health benefit. These results suggest that sinus surgery, as perceived by surgically treated individuals, may be effective in the management of chronic sinus disease.
Psychophysiological therapy for tinnitus.
Twenty-two patients with complaints of severe tinnitus received psychophysiological therapy. Biofeedback sessions were supplemented with body relaxation techniques through the use of audio cassette tapes. The experimental group was matched to a control group according to age and sex. The individuals' names in the control group were placed on a waiting list and received no therapy. Evaluation of the success of the experimental group was obtained at a time period of 6 to 9 months following the therapy sessions. The individuals on the waiting list were also contacted at the same time to assess the severity of their tinnitus symptoms. Results revealed that 60% of the treatment group showed improvement compared to 5% of the control group. The effectiveness of psychophysiological therapy in reducing tinnitus symptoms is supported.
A completely synthetic toxoid vaccine containing Escherichia coli heat-stable toxin and antigenic determinants of the heat-labile toxin B subunit.
The immunodeterminant regions of the Escherichia coli heat-labile toxin B subunit were identified by determining the antigenicity, by using enzyme-linked immunosorbent assays, of synthetically produced peptides corresponding to various segments of its 124-amino-acid sequence. The addition of the 18-amino-acid sequence of heat-stable toxin (ST) to some of these peptides enhanced their B subunit antigenicity. Peptide residues containing the 26 amino acids of B subunit sequence 58 to 83 joined to the 18-amino-acid sequence of ST yielded a 44-amino-acid peptide whose antigenicity was 50% that of both native B subunit and ST. This peptide was completely nontoxic when tested in Chinese hamster ovary tissue culture, suckling mouse, and rat ligated ileal loop assays. Peroral immunization of rats with the polymeric form of this peptide yielded a dose-dependent response of intestinal immunoglobulin A antitoxin titers to both the ST and B subunit components and provided strong protection against challenge with viable ST- and heat-labile toxin-producing E. coli strains. The immunogenicity of the synthetic peptide in rats was the same as that of ST and about 50% that of native B subunit. The completely synthetic peptide vaccine has the following advantages over previously described toxoid vaccines that consist of synthetic ST chemically cross-linked to native B subunit derived from bacterial cultures: it is produced by a single synthetic process, it is completely nontoxic, and it is immunogenic for both ST and B subunit.
Microscopic rhinoscopy in the treatment of inverted papillomas.
Inverted papillomas are endophytic lesions arising from tissues in the nose and paranasal sinuses noted for their local destruction, propensity to recur, and tendency for malignant transformation. It has been well documented that complete removal is essential in the prevention of recurrence; however, use of the operating microscope to ensure this has not been widely described in the past. We present 4 patients, ages 36 to 56, for whom the operating microscope was used intra-operatively and for follow-up examinations. The patients have been followed for 1 to 5 years without any evidence of recurrence to date. We submit that the operating microscope is an extremely valuable tool for the surgical treatment of this lesion in light of the absolute necessity for its complete removal.
Hearing changes following stapedectomy: a six year follow-up.
Audiometric findings of 2405 stapedectomized individuals were subjected to computer analysis. Results are reported in yearly intervals for six years postoperatively. Air and bone conduction thresholds were significantly improved and showed excellent stability over the period of investigation. The high success rate and sustained improvement affirms the use of the Teflon wire piston as the prosthesis of choice for stapedectomy procedure.
Stapedectomy--in depth analysis of 2405 cases.
An optical reader system used in conjunction with a CDC 6400 computer was utilized to obtain data summaries related to the stapedectomy procedure. Medical and audiological data of 2405 cases undergoing surgery for otosclerosis were analyzed. Results are reported in tabular, figurative and descriptive forms.
Intracranial abscesses secondary to ear and paranasal sinuses infections.
The death rate of brain abscesses in a recently reported series is high, ranging from 36% to 50% of all cases. This paper reports experiences with ten cases of intracranial abscesses secondary to ear and sinus infections. Six of these abscesses are secondary to otitic infections with three of them located in the cerebellum. Two of the cerebellar abscesses are surgically drained through the temporal bone by the otologic surgeon, with close neurosurgical cooperation. Computerized axial tomography has revolutionized the treatment of intracranial abscesses optimizing the timing for medical and surgical management.