Molecular epidemiological studies on foot-and-mouth disease type O Taiwan viruses from the 1997 epidemic

Sequence diversity was assessed of the complete VP1 gene directly amplified from 49 clinical specimens during an explosive foot-and-mouth disease (FMD) outbreak in Taiwan. Type O Taiwan FMD viruses are genetically highly homogenous, as seen by the minute divergence of 0.2-0.9% revealed in 20 variants. The O/HCP-0314/TW/97 and O/TCP-022/TW/97 viral variants dominated FMD outbreaks and were prevalent in most affected pig-raising areas. Comparison of deduced amino acid sequences around the main neutralizable antigenic sites on the VP1 polypeptide showed no significant antigenic variation. However, the O/CHP-158/TW/97 variant had an alternative critical residue at position 43 in antigenic site 3, which may be due to selective pressure in the field. Two vaccine production strains (O1/Manisa/Turkey/69 and O1/Campos/Brazil/71) probably provide partial heterologous protection of swine against O Taiwan viruses. The type O Taiwan variants clustered in sublineage A1 of four main lineages in the phylogenetic tree. The O/Hong Kong/9/94 and O/1685/Moscow/Russia/95 viruses in sublineage A2 are closely related to the O Taiwan variants. The causative agent for the 1997 epidemic presumably originated from a single common source of type O FMD viruses prevalent in neighboring areas.

Activation of MAD 2 checkprotein and persistence of cyclin B1/CDC 2 activity associate with paclitaxel-induced apoptosis in human nasopharyngeal carcinoma cells

Paclitaxel (Taxol) is a microtubule-interfering agent that induced persistent and transient G2/M arrest before apoptosis in human nasopharyngeal carcinoma (NPC) cells at high and low concentrations, respectively. In this study, we intended to explore the underlying molecular events and found that cellular cyclin B1/CDC 2 kinase activity was increased and persisted for >6 h upon paclitaxel treatment both at high and low concentrations. Furthermore, activation of MAD 2 checkprotein could account for the loss of cyclin B1 ubiquitination and the persistence of cyclin B1/CDC 2 activation in the cases. To investigate the involvement of cyclin B1 and MAD 2 activation in paclitaxel-induced apoptosis, we introduced affinity-purified anti-cyclin B1 and MAD 2 antibodies into NPC cells by electroporation before the further paclitaxel treatment. The antibodies against cyclin B1 and MAD 2 indeed attenuated paclitaxel-induced cytotoxicity and DNA fragmentation. Our study suggests that activation of cyclin B1/CDC 2 and MAD 2 were the M-phase events required for paclitaxel-induced apoptosis in NPC cells. The dys-regulated cyclin B1/CDC 2 activation could enhance the prometaphase progression, but activation of MAD 2 rendered cells inable to exit from the metaphase. Under this circumstance, cells were probably going to "mitotic catastrophe" and ultimately, destined to apoptosis.

A cell adhesion protein from the crayfish Pacifastacus leniusculus, a serine proteinase homologue similar to Drosophila masquerade

A cDNA encoding a protein resembling masquerade, a serine proteinase homologue expressed during embryogenesis, larval, and pupal development in Drosophila melanogaster, was identified in hemocytes of the adult freshwater crayfish, Pacifastacus leniusculus. The crayfish protein is similar to Drosophila masquerade in the following aspects: (a) overall sequence of the serine proteinase domain, such as the position of three putative disulfide bridges, glycine in the place of the catalytic serine residue, and the presence of a substrate-lining pocket typical for trypsins; (b) the presence of several copies of a disulfide-knotted motif in the putative propeptide. This masquerade-like protein is cleaved into a 27-kDa fragment, which could be detected by immunoblot analysis using an affinity-purified antibody against a synthetic peptide in the C-terminal domain of the protein. The 27-kDa protein could be immunoaffinity-purified from hemocyte lysate supernatant and exhibited cell adhesion activity in vitro, indicating that the C-terminal domain of the crayfish masquerade-like protein mediates cell adhesion.

Repetitive graded ACTH stimulation test for adrenal insufficiency

ACTH stimulation is useful in assessing the hypothalamo-pituitary-adrenal axis. However, there is still some debate about the proper dose and interpretation. We designed a new protocol using repetitive graded ACTH stimulation. Thirty-two patients with the diagnosis of adrenal insufficiency (Al) were studied. After taking samples for baseline ACTH and cortisol, 1 microg fresh-prepared ACTH (Synacthen (1-24)) was injected intravenously, then 5, 50 and 100 microg at hourly interval. Cortisol responses were measured at 30, 60, 120, 180 and 240 min. The secondary Al group (26 subjects) had cortisol responses in between those of the control group (8 subjects) and the primary Al group (6 subjects). The minimal overlap between the secondary Al group and the control group occurred at a 30-min cortisol response after 1 microg ACTH stimulation, using 20 microg/dl as the cut-off level. There was only one exception which showed an episodic release at 30 min. There were 5, 10 and 9 patients with secondary Al who responded normally to 5, 50 and 100 microg ACTH stimulation, respectively. Maximal cortisol increments of the primary Al group were all below 4 microg/dl. Although there were 11 cases of secondary Al whose cortisol responses overlapped with those of primary Al, only two of them had a cortisol increment less than 4 microg/dl. Our new protocol combines the advantage of the low dose ACTH stimulation test, a sensitive method for detecting mild Al, and the ACTH infusion test, a longer test to mimic surgical stress.

In vitro evaluation of GL331's cancer cell killing and apoptosis-inducing activity in combination with other chemotherapeutic agents

GL331 is a novel podophyllotoxin-derived compound and is more efficacious than its congener VP-16 in killing several types of cancer cells, that has promoted considerable interest in its possibility of clinical use. In this study, we found that the higher cytotoxicity of GL331 in nasopharyngeal carcinoma NPC-TW01 cells was attributed to the elevated ability to induce apoptotic cell death. In addition to evaluation of GL331's single agent activity, the use of GL331 in combination with other established therapeutic agents was also evaluated. We found that GL331-induced cell cycle perturbation occurred upon initial 8-h exposure, and pretreatment of NPC-TW01 cells with GL331 for 8 h significantly interfered with the cytotoxicities of VP-16, cisplatin, 5-fluorouracil and adriamycin. When the schedule of drug administration was reversed, high-toxic concentrations of these agents revealed an antagonistic effect on GL331; however, their low-toxic doses had the additive or even more-than-additive effect on the cytotoxicity induced by GL331 at 0.1 microM or less, but for GL331 concentrations of greater than 1 microM, the effect became less than additive. These data suggest that overlapping mechanisms could be elicited by GL331 and other agents, and additional preclinical studies are needed to determine the optimal dose combination and administration schedule that will enhance, rather than interfere with, the efficacy of GL331 in combination with other anti-cancer agents.

Comparison of a Nonradiometric Liquid-Medium Method (MB REDOX) with the BACTEC System for Growth and Identification of Mycobacteria in Clinical Specimens

Early identification of tuberculosis in the clinical setting is of great importance in order for specific therapy to be swiftly initiated. MB REDOX (Heipha Diagnostika), a growth-based medium without radioactive materials, was evaluated and was compared to the BACTEC system for detection of mycobacteria, including the Mycobacterium tuberculosis complex and atypical mycobacteria. MB REDOX consists of a Kirchner medium enriched with growth-promoting additives, antibiotic compounds, and a redox indicator which can be monitored to detect growth of mycobacteria with the naked eye. MB REDOX only detects growth and cannot differentiate the M. tuberculosis complex ( M. tuberculosis , M. bovis , and M. africanum ) from other species of Mycobacterium . Therefore, PCR-restriction fragment length polymorphism analysis (PRA) was used in this investigation to identify to the species level organisms showing positive growth with MB REDOX. Our data demonstrate the usefulness of MB REDOX for the detection of mycobacteria in clinical specimens. The rate of detection of M. tuberculosis complex with MB REDOX (84.3%) was higher than that with the BACTEC system (68.6%). When combined with PRA for species identification, MB REDOX is easy to perform and is suited to most clinical laboratory settings for the detection and identification of mycobacteria.

Effect of speech processor program modifications on cochlear implant recipients' threshold and maximum acceptable loudness levels

This study's purpose was to determine whether or not modifications in speech processor electrical stimulation levels were associated with changes in five Nucleus 22 cochlear implant recipients' thresholds or maximum acceptable loudness levels (MALs). These modifications in minimum and maximum stimulation levels were made to optimize hearing in everyday life. One threshold and one MAL were obtained on each active electrode during six, weekly test sessions, three before and three after program modification. Only one participant had a significant change in threshold after program modification; this participant and four others had significant changes in MAL. Participants' threshold variability was the same, but MAL variability was higher than that observed in other studies. Because these participants had no experience making MAL judgments prior to this study, this result suggests that implant recipients should be given sufficient practice in making MAL judgments to provide a stable clinical estimate of the upper boundary of the electrical dynamic range.

Extent of antibiotic use in Taiwan shown by antimicrobial activity in urine

Taiwan has high prevalence of antibiotic resistant, community-acquired respiratory pathogens. We investigated whether there was a high frequency of antibiotic use in the community. Antimicrobial activity in urine was detected in 55.2% of 1182 patients on arrival at an emergency department, 25.1% of 203 internal medicine out-patients, 7.6% of 471 high school students, and 7.4% of 202 people at a centre for senior citizens.

Line probe assay for rapid detection of mutations in the rpoB gene of Mycobacterium tuberculosis

Detection of mutations in the rpoB gene of Mycobacterium tuberculosis has been reported to be an accurate predictor of rifampin resistance. DNA sequence analysis and screening methods such as single-strand conformation polymorphism analysis and dideoxy fingerprinting are labor-intensive, expensive, or yield results that may prove difficult to interpret. We evaluated the accuracy of a commercial line probe assay for rapid identification and characterization of mutations in the rpoB gene in 72 isolates of M. tuberculosis, including 50 rifampin-resistant and 22 rifampin-susceptible strains. Ten distinct rpoB mutations were identified. Concordances with automated sequencing results and phenotypic rifampin susceptibility testing results were 99% and 93%, respectively. The results demonstrate the line probe assay to be a rapid (as short as 1 day) and informative tool for the early detection and characterization of rpoB mutations associated with rifampin resistance in a clinical laboratory setting.

Impaired adrenal reserve in men with spinal cord injury: results of low- and high-dose adrenocorticotropin stimulation tests

OBJECTIVE

To use low- and high-dose adrenocorticotropin (ACTH) tests to assess adrenal reserve in men with spinal cord injury (SCI).

DESIGN

After an overnight fast, 1 microg and 200 microg ACTH were injected intravenously at time 0 and 60 minutes between 8 AM and 9 AM. Blood was withdrawn at 30-minute intervals from time 0 to 120 minutes.

SETTING

All participants were recruited from the outpatient clinic of a university hospital that is a tertiary referral center.

PARTICIPANTS

Forty-two men with traumatic neurologically complete SCI that had occurred more than 1 year before the study.

MAIN OUTCOME MEASURES

Serum cortisol response to ACTH at times 0, 30, 60, 90, and 120 minutes.

RESULTS

Twenty subjects had a serum cortisol response of <20 microg/dL 30 minutes after a 1-microg ACTH injection; 10 of these remained at this level at 30 minutes after a 200-microg ACTH injection.

CONCLUSION

There is a high prevalence of impaired adrenal reserve in persons with chronic SCI. The 1-microg (low dose) ACTH test is more sensitive for detecting subclinical adrenal insufficiency than is the 200-microg (high dose) ACTH test.

A novel podophyllotoxin-derived compound GL331 is more potent than its congener VP-16 in killing refractory cancer cells

PURPOSE

GL331 is a new homolog of VP-16, and has demonstrated more efficacious anti-cancer activity in both the in vitro and in vivo lymphoma systems. To extensively explore GL331's clinical value, we furthermore evaluate the cytotoxicity and apoptosis-inducing activity of GL331 in several human cell lines from cancers that are not normally treated with VP-16.

METHODS

By MTT and clonogenic survival assays, the cytotoxicities of GL331 and VP-16 were evaluated in a variety of cell lines including nasopharyngeal, hepatocellular, gastric, colon, cervical, and neuroblastoma cancer types. Western blot analysis was performed to detect the MDR-1 level in these cell lines. By Annexin V-staining flow cytometry and detection of DNA ladders, the apoptosis-inducing activities of GL331 and VP-16 were also evaluated.

RESULTS

GL331 showed more efficacy than its congener VP-16 in killing cancer cells. The estimated ID50 of GL331 were 2.5 to 17-fold lowerthan those of VP-16. GL331 possessed more cell-killing activity even in MDR-1-overexpressing cell lines such as HCC36 and SW620. Its higher cytotoxicity could be attributed by the elevated ability to induce apoptotic cell death.

CONCLUSION

GL331's overriding drug resistance and higher cancer cell-killing activity suggest its superiority in clinical cancer therapy.

Detection of antimicrobial activity in urine for epidemiologic studies of antibiotic use

Antibiotic resistance is the inevitable consequence of the selective pressure of antimicrobial drug use and the adaptive plasticity of the microorganisms. Excessive and irrational use of antimicrobial drugs is a problem in all countries. It is particularly troublesome in developing countries where there is a heavy burden of infectious diseases. This study was designed to determine whether detection of antimicrobial activity in the urine might be a useful tool for epidemiologic studies of the interaction between antibiotic use and resistance in developing countries. A laboratory marker is necessary because the history of antimicrobial drug use may be unreliable. Serial specimens or spontaneously voided urine were obtained from healthy volunteers given a single oral dose of commonly used antimicrobial drugs. Urine was also obtained from hospitalized patients the morning after the last dose of an antimicrobial drug and from untreated controls. Assays were performed with standard American Type Culture Collection (Rockville, MD) stains of Bacillus stearothermophilus, Escherichia coli, and Streptococcus pyogenes. Antimicrobial activity could not be detected in pretreatment urine. After a single oral dose, the beta lactam antibiotics and erythromycin could be detected for about 12 to 24 hours, whereas clindamycin, tetracycline, trimethoprim/sulfamethoxazole, and ciprofloxacin could be detected for 48 or more hours. In hospitalized patients, receiving multiple drugs, the following were the sensitivity and specificity for detection of antimicrobial activity: for B. stearothermophilus, 100.0% and 85.9%, respectively; for S. pyogenes, 94.9% and 94.9%, respectively; and for E. coli, 71.8% and 98.7%, respectively. The combination of E. coli and Streptococcus pyogenes exhibited a sensitivity of 97.4% and specificity of 94.9%. Detection of antimicrobial activity in urine is a promising method to determine antimicrobial drug use in epidemiologic studies, particularly in populations in which drug use history is unreliable.

Inhibition of DNA synthesis by downregulation of cyclin A but not Skp 2 overexpression in human hepatocellular carcinoma cells

Cyclin A is an S and G2/M phase regulatory protein and associates with Skp 2 in many transformed cells. Our previous results showed that 12 (39%) and 17 (55%) out of 31 hepatocellular carcinoma (HCC) patients exhibited higher protein expression levels of cyclin A and Skp 2, respectively, in their tumorous compared to non-tumorous tissues. In the present study, we used Western blot analysis to show that 3 out of 6 HCC cell lines, HA59T, HA22T and HCC36, exhibited overexpression of cyclin A, among which the HCC36 cell line also expressed a higher Skp 2 protein level. Moreover, we used the antisense oligonucleotide phosphorothioates to down regulate the overexpression of cyclin A and Skp 2 proteins to determine whether or not these two proteins are involved in the mitogenesis of HCC36 cells. After treatment with antisense oligonucleotide phosphorothioates, the gene product of cyclin A or Skp 2 was suppressed dose-dependently as revealed by Western blot analyses. By [3H]thymidine incorporation assay, we found that downregulation of cyclin A but not Skp 2 overexpression could inhibit the DNA synthesis ability of HCC36 cells, suggesting that abnormal Skp 2 expression is not directly correlated with the HCC proliferation.

Peroxisome proliferation, adipocyte determination and differentiation of C3H10T1/2 fibroblast cells induced by humic acid: induction of PPAR in diverse cells

Humic acid, a high-molecular-weight polyphenolic compound, exists abundantly in soil, natural water, and various terrestrial and aquatic environments. Humic acid causes peroxisome proliferation in mouse liver and induces the expression of peroxisome proliferator activated receptor (PPAR) in BNL CL.2 cells. Both cytotoxicity and flow cytometry show that humic acid inhibits the growth of C3H10T1/2 cells at G1 phase. C3H10T1/2 fibroblast cells express PPARgamma and the adipocyte P2 (aP2) genes which convert into adipocytes after being treated with humic acid. Our findings may provide a unique model for studying the molecular control of determination and differentiation of mesodermal cell lineages.

Three new surgeries for treatment of intractable Meniere's disease

OBJECTIVE

This study aimed to describe the rationales for and preliminary results of three new types of surgery for the treatment of intractable Meniere's disease, all involving insertion of a capillary tube into the endolymphatic duct. This study also aimed to compare the contrasting surgical strategies of endolymphatic sac enhancement versus sac supplantation.

STUDY DESIGN AND SETTING

The study design was a retrospective review of 129 surgeries conducted by the author at Chang Gung Memorial Hospital since 1993: 51 cases of Huang/Gibson inner ear shunt implantation, 52 cases of intraductal capillary tube implantation (ICTI), and 26 cases of ICTIin combination with endolymphatic sac ballooning surgery (ESBS).

PATIENTS

This study is limited to patients with classic Meniere's disease whose vertiginous symptoms were disabling and refractory to dietetic and medical treatment.

MAIN OUTCOME MEASURES

Comparison of preoperative and postoperative conditions (e.g., vertigo control, hearing, disability) using American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) 1985 criteria and chi-square statistical method was measured.

RESULTS

After 1 year of follow-up, use of the Huang/Gibson shunt resulted in a 94.1% vertigo control rate (complete or substantial) and fairly good hearing results, ICTI by itself resulted in an 88.5% rate of vertigo control and relatively unremarkable hearing results, and the ICTI in combination with ESBS (ICTI/ESBS) achieved a vertigo control rate of 96.1% in addition to good hearing results.

CONCLUSIONS

The 1-year follow-up results for Huang/Gibson shunt implantation and sac-preserving ICTI/ESBS have approximately duplicated the excellent performance of the Arenberg implant after the same follow-up period, perhaps attributable in part to enhancement of endolymph flow through the endolymphatic duct.

An atypical iron-responsive element (IRE) within crayfish ferritin mRNA and an iron regulatory protein 1 (IRP1)-like protein from crayfish hepatopancreas

A putative crayfish iron-responsive element (IRE) is present in the 5'-untranslated region of the crayfish ferritin mRNA. The putative crayfish IRE is in a cap-proximal position and shares most of the structural features of the consensus IRE, but the RNA stem-loop structure contains a bulge of a guanine instead of a cytosine at the expected position, so far thought to be a hallmark of IREs. By using an electromobility shift assay this IRE was shown to specifically bind purified recombinant human iron regulatory protein 1 (IRP1) as well as a factor(s) present in a homogenate of crayfish hepatopancreas, likely to be a crayfish IRP1 homologue. With mutations in the crayfish IRE, the affinity of IRP to IRE was drastically decreased. A cDNA encoding an IRP1-like protein was cloned from the hepatopancreas of crayfish. This protein has sequence similarities to IRP, and contains all the active-site residues of aconitase, two putative RNA-binding regions and a putative contact site between RNA and IRP. These results show that a crayfish IRE, lacking the bulged C, can bind IRP1 in vitro and that an IRP1-like protein present in crayfish hepatopancreas may have both aconitase and RNA-binding activities.

Bcl-2 prevents topoisomerase II inhibitor GL331-induced apoptosis is mediated by down-regulation of poly(ADP-ribose)polymerase activity

Poly (ADP-ribose) polymerase (PARP), a nuclear enzyme responsible for DNA strand breaks, has been recently suggested to be crucial for apoptosis induced by a number chemotherapeutic drugs. In this study, we demonstrated that the PARP activity could be evidently elevated with a peak at 6 h when HL-60 cells were treated with a new anticancer drug GL331. Coincident with the peak of PARP activity, an apparent DNA fragmentation and apoptotic morphology were observed in cells treated with GL331. The subsequent apoptotic DNA fragmentation induced by GL331 could be completely blocked by transfecting cells with anti-sense PARP retroviral vector or by treating cells with PARP inhibitor, 3-aminobenzamide (3-AB). This blocking effect thus suggests that activation of PARP was critically involved in GL331-induced apoptosis. The fact that Bcl-2 has been found to antagonize cell death induced by a wide variety of agents, accounts for why we examined whether if Bcl-2 could antagonize GL331 effects. Interestingly, ectopic overexpression of Bcl-2 in either HL-60 or U937 cells caused in resistance towards GL331-elicited DNA fragmentation and cytotoxic effect. Additionally, Bcl-2 also attenuated the poly(ADP-ribosyl)ation of PARP itself as well as Histone H1 at the early period of drug treatment. However, Bcl-2 did not influence the extent of DNA strand breaks induced by GL331 in either control or Bcl-2-overexpressing cells. In addition, analysis of basal PARP activity in control and several Bcl-2 overexpressing clones revealed that Bcl-2 down-regulated PARP activity under the condition without DNA damages. Above findings suggest that poly(ADP-ribosyl)ation of nuclear targets is important for apoptosis induced by DNA-reactive anticancer drugs.

Adenosine triphosphate modification of endotoxin-induced otitis media with effusion in gerbils

BACKGROUND

Impairment of the mucociliary system of the middle ear epithelium is a key step in developing otitis media with effusion. Effective propulsion of the viscoelastic gel layer of mucus requires a control of the depth of the periciliary sol layer by means of epithelial ion transport. In a previous study, we successfully demonstrated modulation of ion transport via short-circuit current changes by specific stimulation of adenosine triphosphate (ATP) receptors in a middle ear cell line.

MATERIALS AND METHODS

Otitis media with effusion was developed in gerbils by infusing Escherichia coli E.coli lipopolysaccaride. In group A, E. coli lipopolysaccharide was first infused, and after establishment of middle ear fluid, the right ear was infused with 10(-4) M ATP, while the left ear remained as the control. In group B, the right ear was infused first with 10(-4) M ATP followed by bilateral infusion with endotoxin. The morphology of the middle ear mucosa was studied using scanning electron microscopy (SEM).

RESULTS

Group A showed fluid clearance in 5 out of 15 ATP-treated right ears while 3 out of 15 left ears showed clearance. Group B showed persistent presence of fluid in 11 out of 15 ATP-treated right ears, while the left ears showed fluid in 13 out of 15. SEM study consistently demonstrated scanty cilia in the non-ATP treated ears, but in ATP-treated ears the cilia remained abundant.

CONCLUSION

Although the results showed that ATP could not effectively prevent or clear middle ear effusion, the SEM result showed a marked beneficial effect of ATP on preserving ciliary configuration.

Extremely high prevalence of nasopharyngeal carriage of penicillin-resistant Streptococcus pneumoniae among children in Kaohsiung, Taiwan

Resistance (intermediate and high) to penicillin among Streptococcus pneumoniae strains is an emerging problem worldwide. From 1995 to 1997, isolates of S. pneumoniae not susceptible to penicillin were seen with increasing frequency from blood, cerebrospinal fluid, pleural fluid, and middle ear fluid from pediatric patients at the Veterans General Hospital-Kaohsiung. To determine the prevalence of carriage of these penicillin-nonsusceptible S. pneumoniae isolates, we obtained nasopharyngeal swab specimens from 2,905 children (ages, 2 months to 7 years) attending day-care centers or kindergartens or seen in our outpatient clinic. S. pneumoniae was isolated from 611 children, and 584 strains were available for analysis. The oxacillin disc test was used as a screening test to evaluate penicillin susceptibility. The MICs of 11 antibiotics (penicillin, cefaclor, cefuroxime, ceftriaxone, cefotaxime, imipenem, chloramphenicol, clarithromycin, rifampin, vancomycin, and teicoplanin) were determined by the E-test. Only 169 (29%) of the strains were susceptible to penicillin; 175 (30%) strains were intermediately resistant and 240 (41%) were highly resistant. The isolates also demonstrated high rates of resistance to other beta-lactams (46% were resistant to cefaclor, 45% were resistant to cefuroxime, 45% were resistant to ceftriaxone, 31% were resistant to cefotaxime, and 46% were resistant to imipenem). The rate of resistance to macrolide antimicrobial agents was strikingly high; 95% of the isolates were not susceptible to clarithromycin. However, 97% were susceptible to rifampin and 100% were susceptible to the two glycopeptides (vancomycin and teicoplanin). While reports of penicillin-resistant S. pneumoniae increased worldwide through the 1980s, the high prevalence (71%) of resistance reported here is astonishing. Surveillance of nasopharyngeal swab specimen cultures may provide useful information on the prevalence of nonsusceptible strains causing invasive disease. Such information could be used to guide therapy of pneumococcal infections.

Positron emission tomography for detecting iodine-131 nonvisualized metastasis of well-differentiated thyroid carcinoma: two case reports

To investigate the usefulness of positron emission tomography (PET) in detecting I-131 nonvisualized metastatic foci of well-differentiated thyroid carcinoma (WDTC), 2 patients with papillary and follicular thyroid carcinoma respectively, were studied with I-131 total body scan, thallium-201 scan, Tc99m bone scan and [18F]-2-deoxy-2-fluoro-D-glucose (FDG) PET. Case 1 showed no metastatic lesion in I-131 (up to 150 mCi) total body scan, 1 anterior mass in thallium-201 scan, none in Tc99m bone scan and 7 including the main anterior mediastinal mass in FDG-PET. Case 2 showed 2 metastatic lesions in I-131 (150 mCi) total body scan, 11 bony metastatic lesions in Tc99m bone scan and 13 in FDG-PET. However, lower extremities were not scanned in FDG-PET. Tumor/background ratio of 1.5 or above is needed to be visualized grossly. The FDG-PET tumor/background ratios are higher than those of thallium-201 except in one site. In conclusion, I-131 scintigraphy is still the first line method to use in detecting WDTC recurrence and metastasis, as I-131 has the advantage of being both a therapeutic and imaging agent. For I-131 nonvisualized metastasis of WDTC, thallium scintigraphy and FDG-PET may be considered. Even though FDG-PET has better sensitivity, resolution imaging and spatial localization, this has to be balanced with its higher cost when compared with thallium scintigraphy.

Dideoxy fingerprinting for rapid screening of rpoB gene mutations in clinical isolates of Mycobacterium tuberculosis

Rifampin is a key component of therapeutic regimens for tuberculosis control, and a marker for multidrug resistance of Mycobacterium tuberculosis. Mutations responsible for conferring rifampin resistance in M. tuberculosis are known to occur in a 69-bp region of the rpoB gene. In this study, we assessed the accuracy of dideoxy fingerprinting (ddF), a hybrid technique employing elements of dideoxy sequencing and single-strand polymorphism analysis, for rapid screening of rifampin resistance in clinical isolates of M. tuberculosis. This technique was used to analyze 72 M. tuberculosis isolates. The results were compared with those of automated dideoxy sequencing and the antibiotic resistance profile (determined with the BACTEC system). Of the 72 isolates, 50 were rifampin resistant. The ddF findings were completely consistent with those of dideoxy sequencing in all isolates. In 68 (94%) isolates, the ddF findings were consistent with the rifampin resistance status determined with the BACTEC system; all four isolates with inconsistent results had no mutation in the 69-bp region, but were resistant to rifampin. Our findings suggest that ddF accurately detects mutations in the rifampin resistance-associated 69-bp region of the rpoB gene in clinical isolates of M. tuberculosis, and may be a valuable screening tool for rifampin resistance.

Cochlear implantation in a patient with osteogenesis imperfecta and otospongiosis

PURPOSE

We describe the findings in a patient with osteogenesis imperfecta (van der Hoeve syndrome) with otospongiosis who received Nucleus 22-channel (Cochlear Pty, Limited, Australia) cochlear implantation. Cochlear implantation in cases of osteogenesis imperfecta with otospongiosis appears to be extremely rare. The syndrome itself and otospongiosis are both associated with debilitating hearing impairment.

METHODS

A female patient who had a triad of brittle bones, blue sclera, and hearing impairment and underwent cochlear implantation was selected for this study.

RESULTS

During surgery, otospongiotic feature of hypervascular, reddish middle-ear mucosa was found. While performing cochleostomy, very soft and brittle cochlear bone was noted, which may be the effect of both osteogenesis imperfecta and otospongiosis.

CONCLUSION

Although cochlear implantation is not always indicated in cases such as described herein, these patients with profound deafness may benefit from it.

Optimization of speech processor fitting strategies for Chinese-speaking cochlear implantees

OBJECTIVES

To compare speech recognition performance in Chinese-speaking cochlear implant patients with a speech processor program selected by the clinical audiologist in Taiwan and with a new speech processor program based on the Washington University clinical procedure developed by Skinner et al.

STUDY DESIGN

Six adult Chinese-speaking patients implanted with the Nucleus cochlear implant system participated in this study.

METHODS

A fitting procedure developed in 1995 by Skinner et al. at Washington University School of Medicine was used to create a new speech processor program to optimize each patient's hearing in everyday life. Speech tests (vowels, consonants, tones, and words), sound-field thresholds, and a self-report questionnaire were used to evaluate each patient's performance with his or her previous speech processor program and a new one.

RESULTS

Four of the six patients had significant changes from the previous to the new speech processor program. These changes were associated with improvement in score on at least one speech test, more sensitive sound field thresholds, and reported improvement in some everyday listening situations on the questionnaire.

CONCLUSIONS

These results suggest that use of this procedure with adult cochlear implantees may improve benefit in everyday life. Analysis of the speech test stimuli and patients' responses provides a basis for modification or creation of new Mandarin Chinese speech tests for preoperative and postoperative evaluation of adult cochlear implant patients.