Usefulness of mid-week hemoglobin measurement for anemia management in patients undergoing hemodialysis: a retrospective cohort study

Background

Short-term hemoglobin (Hb) variability related to volume status is observed in chronic kidney disease (CKD) patients receiving hemodialysis (HD). Given the lack of studies regarding outcomes according to the day of Hb sampling, the existing guidelines do not strongly recommend regarding measurement timing. Pre-dialysis mid-week sampling (Wednesday and Thursday) is preferable to minimize short-term Hb variability, although numerous HD centers perform early-week sampling (Monday and Tuesday). The different measurement days may influence the prescribed dose of erythropoiesis-stimulating agent (ESA) and related patient outcomes. We investigated changes in Hb levels and ESA doses according to the Hb measurement day among HD patients.

Methods

Starting September 2013, the day for pre-dialysis Hb measurement at the Asan Medical Center was changed from early-week days to mid-week days. This single-center retrospective study evaluated medical records of 92 patients who received maintenance HD between September 2012 and August 2014.

Results

There was no significant difference in the mean Hb levels between early-week days and mid-week days (10.71 ± 0.06 g/dL vs. 10.78 ± 0.47 g/dL, p = 0.105). However, the mean doses of darbepoetin-α on early-week days were higher than those on mid-week days (175.4 ± 72.5 μg/month vs. 163.7 ± 83.6 μg/month, p = 0.022). The mean doses of intravenous iron hydroxide sucrose for early-week measurements were also higher than those for mid-week measurements (623.0 ± 489.0 mg/year vs. 447.0 ± 505.2 mg/year, p = 0.001). The mean interdialytic weight gains were 2.81 ± 0.82 kg on early-week days and 1.99 ± 0.61 kg on mid-week days (p < 0.001).

Conclusions

Compared with early-week measurements, mid-week pre-dialysis Hb measurements were significantly associated with lower ESA doses without a change in Hb levels.

Early development of de novo hepatocellular carcinoma after direct-acting agent therapy: Comparison with pegylated interferon-based therapy in chronic hepatitis C patients

Patients with chronic hepatitis C who achieve a sustained viral response after pegylated interferon therapy have a reduced risk of hepatocellular carcinoma, but the risk after treatment with direct-acting antivirals is unclear. We compared the rates of early development of hepatocellular carcinoma after direct-acting antivirals and after pegylated interferon therapy. We retrospectively analysed 785 patients with chronic hepatitis C who had no history of hepatocellular carcinoma (211 treated with pegylated interferon, 574 with direct-acting antivirals) and were followed up for at least 24 weeks after antiviral treatment. De novo hepatocellular carcinoma developed in 6 of 574 patients receiving direct-acting antivirals and in 1 of 211 patients receiving pegylated interferon. The cumulative incidence of early hepatocellular carcinoma development did not differ between the treatment groups either for the whole cohort (1.05% vs 0.47%, P = .298) or for those patients with Child-Pugh Class A cirrhosis (3.73% vs 2.94%, P = .827). Multivariate analysis indicated that alpha-fetoprotein level >9.5 ng/mL at the time of end-of-treatment response was the only independent risk factor for early development of hepatocellular carcinoma in all patients (P < .0001, hazard ratio 176.174, 95% confidence interval 10.768-2882.473) and in patients treated with direct-acting agents (P < .0001, hazard ratio 128.402, 95% confidence interval 8.417-1958.680). In conclusion, the rate of early development of hepatocellular carcinoma did not differ between patients treated with pegylated interferon and those treated with direct-acting antivirals and was associated with the serum alpha-fetoprotein level at the time of end-of-treatment response.

Rapid genotyping of Plasmodium vivax Pvs25 and Pv38 genes by using mismatch specific endonuclease

Mismatch specific endonuclease (MSE) method was used to detect natural polymorphisms in Pvs25 and Pv38 genes of Plasmodium vivax. Eighty seven patients with P. vivax were recruited in the Republic of Korea (ROK). Pvs25 and Pv38 genes were amplified by polymerase chain reaction (PCR), and the PCR amplicons were mixed with reference DNA sequences. Following the denaturation and gradual annealing, the product mixtures were cleaved by the MSE. Heteroduplex types were readily detected by gel electrophoresis, where extra bands with shorter sizes would appear from the cleavage. After MSE cleavage of 657- bp product from Pvs25 mixtures, three genotypes were detected, while Pv38 mixtures with 1220-bp products presented two genotypes in ROK isolates. After the MSE cleavage, the mismatched samples of Pvs25 and Pv38 were completely sequenced, and the results were in complete agreement with the MSE analyses. In conclusion, genotyping of Pvs25 and Pv38 with MSE cleavage could be a potential method for the high-throughput screening of the large field samples.

Dynamic changes of the inflammation-based index predict mortality following chemoembolisation for hepatocellular carcinoma: a prospective study

BACKGROUND

Transarterial chemoembolisation (TACE) is a standard treatment for unresectable, intermediate stage hepatocellular carcinoma (HCC). Survival after TACE, however, can be highly variable, with no suitable biomarker predicting therapeutic outcome. The inflammation-based index (IBI) has previously been shown to independently predict overall survival (OS) in all stages of HCC.

AIM

To explore the prognostic ability of IBI as a predictor of survival after TACE.

METHODS

Baseline staging, biochemical and clinicopathological features including IBI were studied in a derivation set of 64 patients undergoing TACE for intermediate stage HCC. Dynamic changes in IBI before and after TACE were studied as predictors of survival using both a univariate and multivariate Cox regression model and further validated in two independent patient cohorts from Korea (n = 76) and Japan (n = 577).

RESULTS

Pre-treatment IBI predicted for OS in the derivation set (P = 0.001). Other univariate predictors of OS included radiological response to TACE (P < 0.001), pre-TACE CLIP score (P < 0.01), tumour diameter >5 cm (P = 0.05) and AFP ≥400 (P < 0.001). Normalisation of IBI post-TACE was associated with radiological response by mRECIST criteria and improved OS (P < 0.001). Normalisation of IBI remained a significant multivariate predictor of OS in both the derivation and validation sets (P < 0.001).

CONCLUSIONS

Normalisation of IBI after TACE is shown to be an independent predictor of survival and may be integrated into the retreatment criteria for repeat TACE in intermediate stage HCC. IBI and its dynamic changes after treatment are validated as a biomarker allowing the stratification of patients with a significant survival advantage following initial TACE.

Combinations of eight key mutations in the X/preC region and genomic activity of hepatitis B virus are associated with hepatocellular carcinoma

Accumulation of eight key mutations located in the X/preC regions of the hepatitis B virus (HBV) genome (G1613A, C1653T, T1753V, A1762T, G1764A, A1846T, G1896A and G1899A) is a risk marker for the development of hepatocellular carcinoma (HCC). In this study, we analysed the 8 key mutations in 442 serum samples collected from 310 non-HCC and 132 HCC patients to identify the combinations linked to HCC. After the patients were stratified according to the age groups and mutation combinations, clinical parameters were compared between the HCC and the non-HCC groups. Analyses were focused on patient ≥40 years of age infected by HBV genotype C with A1762T and G1764A mutations in the basal core promoter region (BCP double mutation). In patients with ≥6 mutations, the combination of [G1613A + C1653T + A1846T + G1896A] mutations was closely linked to HCC, whereas no specific single or double mutation combination was associated with HCC. In patients with ≤5 mutations, HBeAg and HBV DNA serum titres were lower in the HCC group than those in the non-HCC group. Unlike the number of mutations, no specific combination correlated with advanced clinical stage in HCC. Of the BCP double mutation-based HBV mutant types, combinations of ≥6 mutations that include G1613A + C1653T + A1846T + G1896A, and combinations of ≤5 mutations with reduced HBeAg production, may be more specific indicators of HCC risk than only the number of mutations or any specific combination(s).

Endoscopic versus open release in patients with de Quervain's tenosynovitis: a randomised trial

The purpose of this study was to compare the outcome and complications of endoscopic versus open release for the treatment of de Quervain's tenosynovitis. Patients with this condition were randomised to undergo either endoscopic (n = 27) or open release (n = 25). Visual Analogue Scale (VAS) pain and Disabilities of Arm, Shoulder, and Hand (DASH) scores were measured at 12 and 24 weeks after surgery. Scar satisfaction was measured using a VAS scale. The mean pain and DASH scores improved significantly at 12 weeks and 24 weeks (p < 0.001) in both groups. The scores were marginally lower in the endoscopic group compared to the open group at 12 weeks (p = 0.012 and p = 0.002, respectively); however, only the DASH score showed a clinically important difference. There were no differences between the groups at 24 weeks. The mean VAS scar satisfaction score was higher in the endoscopic group at 24 weeks (p < 0.001). Transient superficial radial nerve injury occurred in three patients in the endoscopic group compared with nine in the open release group (p = 0.033). We conclude that endoscopic release for de Quervain's tenosynovitis seems to provide earlier improvement after surgery, with fewer superficial radial nerve complications and greater scar satisfaction, when compared with open release.

Pretreatment HBeAg level and an early decrease in HBeAg level predict virologic response to entecavir treatment for HBeAg-positive chronic hepatitis B

There are few reports on hepatitis B e antigen (HBeAg) titres during nucleos(t)ide analogues treatment. We investigated the changes in HBeAg levels in patients treated with entecavir and the usefulness of HBeAg quantification for predicting antiviral response. Ninety-five consecutive HBeAg-positive patients treated with entecavir for more than 48 weeks were enrolled. Serum levels of hepatitis B surface antigen (HBsAg), HBeAg and HBV DNA were assessed at 4-week intervals to week 24 and thereafter at 12-week intervals. Virologic response (Y1VR) was defined as an undetectable HBV DNA level at week 48 of therapy. During 48 weeks, HBeAg and HBV DNA level decreased significantly in a biphasic manner and HBsAg level tended to decease. Fifty-three patients (55.8%) attained Y1VR. Pretreatment HBeAg levels were significantly lower in the Y1VR group than in no Y1VR group. At week 4 and 12 of therapy, 25% and 41.4% of patients showed a decrease of HBeAg levels with >0.5 log(10) and >1.0 log(10) from baseline, respectively. These patients achieved more Y1VR than those with less decrease of HBeAg levels (97.7%vs 22.2% and 86.2%vs 29.3%, respectively). HBeAg level at week 12 had higher predictive values for Y1VR than HBV DNA level. Multivariate analysis revealed that a pretreatment HBeAg level of <360 PEIU/mL and the reduction in HBeAg level >1.0 log(10) at week 12 were associated with Y1VR. These results suggest that pretreatment HBeAg level and an early decrease in HBeAg level are useful measurements for predicting one-year virologic response during entecavir treatment.

Serum hepatitis B surface antigen levels in the natural history of chronic hepatitis B infection

BACKGROUND  The production of hepatitis B surface antigen (HBsAg) may evolve during long-lasting virus-host interactions in chronic hepatitis B (CHB). The impact of age on HBsAg production remains unclear. AIM  To determine the age-specific distribution patterns of HBsAg and related factors during the natural course of CHB infection. METHODS  Seven hundred and sixty-eight untreated HBsAg carriers were enrolled in the study. The parameters and distribution patterns of HBsAg were evaluated in relation to age and immune phases. RESULTS  The HBsAg levels were significantly lower in the HBeAg-negative stage, with the lowest levels in inactive carriers. The HBsAg tended to decrease from hepatitis to cirrhosis and to hepatocellular carcinoma, and from Child-Pugh class A to B and to C. Age and HBV DNA were independently associated with HBsAg levels. In HBeAg-positive patients, the HBsAg levels were distributed in a triphasic-like decline pattern by 2 logs across age strata. For HBeAg-negative patients, the titres in inactive carriers exhibited a 2-log reduction, but remained unchanged over age strata in patients with HBeAg-negative hepatitis. The ratios of HBsAg/HBV-DNA were highest, but steadily decreased with age in inactive carriers, whereas the levels remained largely unchanged over the entire age strata in patients with HBeAg-negative hepatitis. CONCLUSIONS  Age and HBV DNA levels are independent parameters of HBsAg levels. During the natural course of CHB infection, HBsAg levels decrease with age and disease progression, but the patterns are significantly different between the immune phases of CHB. This information may contribute to our understanding of the immunopathogenesis of chronic hepatitis B and management involving HBsAg quantification.

Benefit of downsizing hepatocellular carcinoma in a liver transplant population

BACKGROUND

Long-term results after downstaging hepatocellular carcinoma (HCC) prior to liver transplantation (LT) remain unknown.

AIMS

To investigate dropouts and post-transplant outcome among patients with downstaged HCC by transarterial chemo-lipiodolization (TACL).

METHODS

Between 2000 and 2007, 386 patients with HCC initially exceeding Milan criteria underwent TACL for tumour downstaging and were consecutively enrolled.

RESULTS

Overall, 160 (41.5%) patients achieved successful downstaging of HCC to within Milan criteria. During the follow-up, 82 eventually dropped off the waiting list for LT, with estimated dropout rates at 1, 2 and 5 years of 46.7%, 70.2%, and 87.2%, respectively. The overall post-transplant survival rates at 1, 2 and 5 years were 89.2%, 70.3% and 54.6% and the corresponding rates for recurrence-free survival were 74.7%, 71.8% and 66.3% respectively. Multivariate analysis indentified alpha-fetoprotein (AFP) levels > or = 100 ng/mL at LT (P = 0.003), maximum tumour size > or = 7 cm (P = 0.002) and the lack of complete necrosis by TACL (P = 0.048) as independent predictors of HCC recurrence after LT. Patients with none of these risk factors had an excellent post-transplant outcome, with an 87.5% probability of recurrence-free survival up to 6 years.

CONCLUSIONS

These long-term results may contribute to the database for optimizing management of LT candidates with downstaged HCC. Based on our data, patients with a maximum tumour size <7 cm who achieve complete necrosis together with AFP levels <100 ng/mL at LT may be the best candidates for LT following downstaging using TACL.

Electrically tunable slow and fast lights in a quantum-dot semiconductor optical amplifier near 1.55 microm

We have demonstrated both slow light in the absorption regime and fast light in the gain regime of a 1.55 microm quantum-dot semiconductor optical amplifier at room temperature. The theory with coherent population oscillations and four-wave mixing effects agrees well with the experimental results. We have observed a larger phase delay at the excited state than that at the ground state transition, likely due to the higher gain and smaller saturation power of the excited state.

The best candidates for transarterial chemotherapy in patients with hepatocellular carcinoma awaiting liver transplantation: a cohort-based characterization of dropout times

BACKGROUND

Although transarterial chemotherapy is used to retard tumour progression for hepatocellular carcinoma (HCC) patients awaiting orthotopic liver transplantation (OLT), information regarding the acceptable waiting time and appropriate patient selection for the therapy is lacking.

AIM

To examine dropout times and determine the best candidates for pre-transplant transarterial therapy in a cohort study.

METHODS

In total, 180 consecutive HCC candidates receiving pre-transplant chemo-lipiodolization were included in the study.

RESULTS

Overall, 70 (38.9%) patients dropped off the waiting list during the median follow-up of 19 months. According to the Child-Pugh (C-P) classification, the estimated dropout rates at 1 and 2 years were 17.2% and 44.8% for the C-P A group and 33.4% and 81.3% for the C-P B/C group, respectively. C-P B/C patients experienced more frequent dropouts than C-P A patients (P < 0.001). Risk factor analysis identified C-P classification to be the strongest predictor of dropout (P < 0.001). On multivariate analysis, alpha-fetoprotein (AFP) >100 ng/mL, tumour size >3 cm and multiple nodules remained independently predictive of dropout for C-P A group (all P < 0.05). Candidates with none of these factors were found to be at the lowest risk of dropout, with only a 22.5% dropout rate up to 41 months.

CONCLUSIONS

This study suggests that Child-Pugh A patients with one nodule <3 cm and AFP < 100 ng/mL may be the best candidates for pre-transplant chemo-lipiodolization, with the lowest dropout rate. However, comparative studies with other therapeutic options are needed to assess the definitive role of transarterial therapy in this setting.

A 13-year longitudinal study of the impact of double mutations in the core promoter region of hepatitis B virus on HBeAg seroconversion and disease progression in patients with genotype C chronic active hepatitis

The pathogenic role of core promoter (CP) mutations (T1762/A1764) of hepatitis B virus (HBV) in hepatitis B e antigen (HBeAg) seroconversion or disease progression remains unclear. We investigated the clinical relevance of these mutants over a long-term follow-up period of up to 15 years. In this longitudinal cohort study, 29 HBeAg-positive patients with biopsy-proved chronic active hepatitis without cirrhosis were regularly monitored for >10 years. The viral isolates were characterized, using the frozen liver tissue obtained on the day of biopsy. Long-term outcomes were compared between patients with and without CP mutations of HBV at baseline. HBV genotyping showed that 100% of study subjects were infected with genotype C HBV. During a median follow-up period of 12.5 years, patients without double CP mutations of HBV at baseline showed a tendency towards achieving an earlier HBeAg seroconversion than those with (6.9 vs 9.4 years, P = 0.062) double CP mutations. Double CP mutations at baseline were also significantly associated with the eventual development of cirrhosis or hepatocellular carcinoma (P = 0.013), whereas the absence of double CP mutations predicted inactive carrier status at the last follow-up (P = 0.027). At 10 years, liver-related tests were also significantly better in patients without double CP mutations of HBV than in those with these mutations, as reflected by higher platelet counts and albumin levels (P = 0.036 and P = 0.044, respectively). Double T1762/A1764 mutations are significantly related to liver deterioration in HBeAg-positive genotype C active hepatitis patients. A longer period of immune clearance coupled with delayed HBeAg seroconversion appears to contribute to disease progression in patients harbouring these mutations in the CP region of HBV.

Perforating disorder caused by salt-water application and its experimental induction

BACKGROUND

Perforating disorders are uncommon diseases characterized by transepidermal elimination histopathologically and include reactive perforating collagenosis, elastosis perforans serpiginosa, Kyrle's disease and perforating folliculitis. In addition, perforating disorders can develop in patients with diabetes mellitus, renal failure and even by accidental exposure of calcium salts.

METHODS

We report two cases of perforating disorder caused by chemical burn with commercially available salt-water application for self-treatment of chronic dermatitis or pruritus.

RESULTS

The commercially used salt water for making bean curd was analyzed and it consisted of calcium and other salts without harmful heavy metals. We induced a similar phenomenon by experimental application of commercial salt water on guinea pigs.

CONCLUSION

Bean curd is used as a food commonly in the Far-East, allowing a greater chance of exposure to salt water accidentally or occupationally. Bean curd is becoming more popular even in Western countries. To confirm causation, we induced a similar phenomenon in guinea pigs by experimental application of commercial salt water.

Enhanced thermal stability of an alkaline protease, AprP, isolated from a Pseudomonas sp. by mutation at an autoproteolysis site, Ser-331

The thermal stability of the alkaline protease extracellular subtilisin-type serine protease (AprP) from Pseudomonas sp. KFCC 10818 was improved by altering an amino acid residue at an autoproteolytic cleavage site. N-terminal sequence analysis of the autoproteolytic products of the protein revealed the presence of two cleavage sites, Ser-307 and Ser-331. To increase the thermal stability of the enzyme, serine residues of these sites were replaced with aspartate. The S331D mutant enzyme was successfully purified and characterized whereas the S307D mutant was not. The half-lives of the S331D mutant at 55 degrees C and 60 degrees C were 1.5 and 2.4 times longer than that of the wild-type enzyme, respectively. In addition, the catalytic efficiency was also enhanced.

Analysis of matrix metalloproteinase mRNAs expressed in hepatocellular carcinoma cell lines

To analyze matrix metalloproteinase (MMP) mRNAs that are expressed in hepatocellular carcinoma cell lines, the kinds of MMP mRNAs were surveyed in HepG2 and Hep3B cells and normal liver by a reverse transcription-polymerase chain reaction using two degenerate primer pairs, derived from conserved domains of known MMPs. The level for each MMP mRNA was examined by Northern blot analysis in HepG2 and Hep3B cells, as well as in normal tissues. It was also examined by a reverse transcription-polymerase chain reaction analysis in 8 different hepatocellular carcinoma cell lines. MMP-2, MMP-14, and MMP-15 mRNAs were expressed at elevated levels in most of the cell lines studied, reflecting that these MMPs would play an important role in the invasion and metastasis of hepatocellular carcinoma. MMP-1, MMP-3, MMP-8, MMP-10, MMP-11, and MMP-13 mRNAs were also expressed in some or most of the cell lines. Interestingly, MMP-9 mRNA, as well as its polypeptide, was undetected in all of the cell lines studied. This implies that MMP-9, which was suggested as a tumor marker for hepatocellular carcinoma, would be expressed in stromal cells, rather than tumor cells. These results provide information for the basal levels of MMP mRNAs in various hepatocellular carcinoma cell lines. It will also facilitate study on the transcriptional regulation of each MMP mRNA by oncogenes.

Bacteriology of chronic sinusitis after amoxicillin-clavulanate potassium therapy

The bacteriology of chronic sinusitis was studied after amoxicillin-clavulanate potassium therapy. Patients with chronic sinusitis were randomly divided into 2 groups. In the study group, 90 patients were given a 2-week course of amoxicillin-clavulanate potassium before functional endoscopic sinus surgery. In the control group, 113 patients did not take any antibiotics within 2 weeks before the surgery. Swab specimens were taken from the maxillary and ethmoid sinuses during surgery and sent for aerobic and anaerobic culture. In the study group, the culture rates of maxillary and ethmoid sinuses were 45.6% and 28.9%, respectively. In the control group, the culture rates of maxillary and ethmoid sinuses were 53.1% and 34.5%, respectively. The culture rates between the control group and the study group were not significantly different, either for the maxillary sinus or the ethmoid sinus. This showed that treatment with amoxicillin-clavulanate potassium did not change the bacteriology of chronic sinusitis.

Endostatin inhibits endothelial and tumor cellular invasion by blocking the activation and catalytic activity of matrix metalloproteinase

Here we report the inhibition of cellular invasion by a recombinant mouse endostatin and the possible mechanism of the inhibition. Endostatin significantly reduced endothelial as well as tumor cellular invasion into the reconstituted basement membrane in vitro. Gelatin zymographic analysis revealed that the activation of promatrix metalloproteinase-2 (proMMP-2) that was secreted from endothelial cells was blocked upon endostatin treatment. Studies with recombinant MMPs confirmed that endostatin inhibited proMMP-2 activation, mediated by both membrane-type 1 MMP and 4-aminophenylmercuric acetate. Furthermore, enzymatic assays using a peptide substrate demonstrated that endostatin inhibited the catalytic activities of both MMP-2 and membrane-type 1 MMP. Finally, coimmunoprecipitation experiments revealed that endostatin formed a stable complex with proMMP-2. These novel findings would, at least in part, explain the mechanism of the potent antiangiogenic and antitumor activities of endostatin.

Effects of intraoperative blood flow on the early patency of radiocephalic fistulas

The purpose of this study was to find the correlation between intraoperative blood flow and early patency of the radiocephalic fistula. Between March 1998 and March 1999, 50 radiocephalic arteriovenous fistulas were constructed in 41 patients. Intraoperative blood flow measurements were made 10 min after completion of the vascular anastomoses with 3-4 mm handheld flow probes. Patients were followed until failure of fistula or 3 months after the first hemodialysis with these fistulas. Intraoperative blood flow as well as age, gender, presence of diabetes, size of cephalic vein, thrill on the fistula, and flow of radial artery were correlated with early patency. The mean intraoperative blood flow was 174.7 +/- 13.2 mL/min and ranged from 50 to 500 mL/min; it was the only significant parameter that determined early patency of the radiocephalic fistula. Fistulas with flow <160 mL/min (10 of 25) had a higher failure rate than those with flow >160 mL/min (4 of 25), which was statistically significant (p < 0.01). All of the patients with flow <70 mL/min (5 of 5) failed to maintain patency within a month. However, the other variables were not correlated with early patency. We conclude that intraoperative blood flow is a reliable parameter that determines the early patency of radiocephalic fistulas.

Osseous metaplasia with functioning bone marrow in hydroxyapatite orbital implants

BACKGROUND

Bone formation within the hydroxyapatite implant has been reported in explanted spheres in humans. Bone-specific differentiation was observed to occur earlier in the pores of spherical hydroxyapatite implants enhanced with osteogenin within the rabbit socket. We observed previously unreported bone marrow formation in a coralline hydroxyapatite implant placed into the rabbit orbit after evisceration.

METHODS

One eye of each of 10 New Zealand white rabbits weighing between 2 and 3 kg was eviscerated and implanted with hydroxyapatite spheres. The explanted hydroxyapatite spheres 20 weeks after surgery were examined under the microscope.

RESULTS

Histopathologic examination of the excised implants showed the presence of trabeculae of mature bone with fatty marrow and hematopoietic elements. Scattered throughout the fatty tissue were bone marrow elements consisting of precursors of the granulocytic and erythroid series and also megakaryocytes.

CONCLUSION

The osseous metaplasia with functioning bone marrow was incidentally observed in the coralline hydroxyapatite implant without the addition of any osteogenesis-inducing agents.

The effects of high-dose corticosteroid therapy on optic nerve head blood flow in experimental traumatic optic neuropathy

PURPOSE

The objective of this study was to ascertain the effect of high-dose steroid therapy in traumatic optic neuropathy using the Heidelberg retina flowmeter (HRF) to detect changes in optic nerve head blood flow.

METHODS

We experimentally damaged the optic nerves of 10 white rabbits with a Hartman mosquito clamp. The first group (n = 5) was treated with intravenous dexamethasone (0.25 mg/kg) every 6 h for a 48-hour period. The second group (n = 5) served as controls. Both groups were tested prior to operation, 1 week, 1 month and 2 months after surgery.

RESULTS

Experimental optic nerve damage caused a significant decrease in optic nerve head blood flow of 50.51% (p = 0.001), with a volume decrease of 46.02% (p = 0.001) and a velocity reduction of 43.12% (p = 0.002) compared to the baseline. After 2 months, in the group treated with high-dose corticosteroid therapy, optic nerve head blood flow was increased by 76.90% (p = 0.012), volume by 77.53% (p = 0.012) and velocity by 47. 21% (p = 0.012) compared to the control group.

CONCLUSION

The high-dose corticosteroid therapy improved the optic nerve head blood flow as demonstrated in experimental traumatic optic neuropathy. The HRF may be used to assess the therapeutic responses in traumatic optic neuropathy under variable conditions.

Bacteriology of endoscopically normal maxillary sinuses

The bacteriology of maxillary sinuses with normal endoscopic findings is reported in this study. When transantral sinoscopy was used to examine the maxillary sinuses, the whole maxillary sinus was inspected with different-angle endoscopes. If no lesion was seen over the whole maxillary sinus mucosa, no secretion existed in the maxillary sinus cavity, and the maxillary sinus ostium was wide open, the maxillary sinus was considered endoscopically normal. The bacteriology of these endoscopically normal maxillary sinuses was studied by passing cotton-tipped sticks through the cannula to collect swab specimens. In some cases, a biopsy forceps was also passed to obtain mucosal specimens. The specimens were sent to the laboratory for aerobic and anaerobic cultures. Between July 1990 and May 1998, 83 swab and 31 mucosal specimens were collected from 69 patients who had not taken any antibiotic within 10 days before endoscopy. The culture rates were 62.3 per cent (35/53) from swab specimens and 57.1 per cent (eight out of 14) from mucosal specimens in patients with the diagnosis of chronic paranasal sinusitis, and were 46.7 per cent (14/30) from swab specimens and 41.2 per cent (seven out of 17) from mucosal specimens in patients without this diagnosis. This study shows that endoscopically normal maxillary sinuses are not sterile.

Post-functional endoscopic sinus surgery methicillin-resistant Staphylococcus aureus sinusitis

Methicillin-resistant Staphylococcus aureus (MRSA) is a highly virulent bacterium that is difficult to eradicate. It has become a common nosocomial pathogen, but it also causes sporadic infections in some outpatients. Among 358 chronic sinusitis patients who received functional endoscopic sinus surgery (FESS) for treatment between July 1995 and June 1997 in our department, 18 were infected postoperatively by MRSA by the end of August 1997. One patient was excluded because she received another nasal surgery, partial turbinectomy, and submucous resection of the nasal septum, after FESS. Most of 17 MRSA infected patients presented themselves with mucopurulent nasal discharge and/or nasal crust. The treatment was generally difficult because MRSAs were resistant to multiple antibiotics. When quinolone antibiotics were used to treat most patients, the improvement rate was 76.5%. We conclude that MRSA infections in post-FESS patients might affect the outcome of FESS.

Low-Temperature Formation of alpha-Alumina by Doping of an Alumina-Sol

In our present study, the phase transition behavior of gamma-alumina doped by an alumina-sol was explored using X-ray powder diffraction and transmission electron microscopy. It was found that the addition of an alumina-sol into gamma-alumina enabled the onset of the gamma- to alpha-alumina transformation at temperatures as low as 600 degreesC. This phenomenon was designated as the "sol-effect." Although the onset temperature of the phase transformation was very low, the transformation was completed at 1100 degreesC which is the same as that observed with the seeding method. Further investigation revealed that the transformation was composed of two steps. One occurs over the temperature region from 600 to 950 degreesC where a slow increase in the content of alpha-alumina is observed. The other is the region from 950 to 1100 degreesC where a rapid increase of alpha-alumina occurs due to "self-seeding." The "sol-effect" produces powders with very fine alpha-alumina particle sizes and little agglomeration. Copyright 1999 Academic Press.

Endoscopic sinus surgery and postoperative intravenous aminoglycosides in the treatment of atrophic rhinitis

A total of 29 atrophic rhinitis patients were treated by endoscopic sinus surgery between 1990 and 1995. After the surgery, a 7 to 10-day course of systematic aminoglycoside was administered. Two cases were excluded, due to later occurrence of nasal lymphoma in one patient and incompleteness of postoperative antibiotic therapy in the other. Among those included, atrophic rhinitis occurred in the absence of prior surgery in 24 patients, and the condition was secondary to a previous intranasal surgery in the other three patients. After a 1 to 6-year follow-up (mean: 63.4 months), seven patients were successfully managed without any characteristic symptom or sign of atrophic rhinitis. Another 18 patients felt improved. Only two patients did not have any improvement. The rate of improvement was 92.6%. Overall, one patient suffered from a left retrobulbar hematoma after operation. Exposed orbital fat was observed in the other patient. The orbital complication rate was therefore 7.4%. No other major complication occurred in this series. The bacteriologic, radiological, antroscopic, and pathologic findings are also included here. It is concluded that endoscopic sinus surgery in combination with adequate postoperative antibiotic therapy can significantly treat atrophic rhinitis.

Bacteriology of the maxillary and ethmoid sinuses in chronic sinusitis

The bacteriology of chronic sinusitis was studied by using swab and mucosal specimens from both the maxillary and ethmoid sinuses. The specimens of the maxillary sinus were taken through translabial antroscopy. The specimens of the ethmoid sinus were taken after removing the ethmoid bulla during functional endoscopic sinus surgery (FESS). Eighty-six samples of each type of specimen were collected. Among the maxillary sinus samples, the culture rate was 60.5 per cent from the swab specimens and 36 per cent from the mucosal specimens. Among the ethmoid sinus samples, the culture rate was 58.1 per cent from the swab specimens and 75.6 per cent from the mucosal. The p-value by the Chi-Square test is higher than 0.01 (p = 0.015). As there were more isolates of Staphylococcus epidermidis from the mucosal specimens, they are not a better choice of specimen for sampling the ethmoid sinus than a swab specimen.

Comparison of corneal centering in photorefractive keratectomy

The present study compares three centering methods for excimer laser photorefractive keratectomy (PRK. VISX 20/20) by analyzing the corneal topography. The subjects were grouped according to three different centering methods used in the procedure: an ablation using a light reflex from the patient's cornea pursued by both eyes of the surgeon (Group 1, n = 49); an ablation using a red light reflex from the patient's cornea pursued by the surgeon's left eye only while the right eye remained closed (Group 2, n = 27); an ablation using the patient's center of the pupil pursued by the surgeon's left eye only while the right eye remained closed (Group 3, n = 21). The mean distance from the center of ablation zone to the center of the pupil were; 0.69 +/- 0.45 mm for Group 1, 1.05 +/- 0.48 mm for Group 2 and 0.63 +/- 0.28 mm for Group 3. The degree of deviation in Group 2 was significantly greater than in Group 1 or Group 3. The deviation was greater in the right eyes than the left eyes in Group 2 only. The decentration of the right eye in Group 2 was due to angle Kappa with misalignment of the fixation light and viewing tube containing reticule.

The effect of excipients on glass transition temperatures for FK906 in the frozen and lyophilized states

FK906, a tripeptide, has been used as a model compound to study the effect of excipients on the glass transition temperature for peptides and related compounds in the frozen solution and lyophilized states. Three kinds of excipients were chosen for study, low molecular weight sugars, high molecular weight polymers and salts. Our results indicate that the Gordon-Taylor equation can be used to predict the glass transition temperature of FK906 in the presence of sucrose, lactose, trehalose and maltose in the frozen solutions and in lyophilized products. Dextrans having different molecular weights can have different effects on the glass transition temperature of FK906 in the frozen state. Cooling rate can also have an effect on the glass transition temperature for FK906 frozen solutions in the presence of dextran. Finally, salts have a significant effect on the glass transition temperature of FK906 in the frozen state but not in lyophilized FK906.

Some physicochemical properties of FK906: glass transition and relaxation

FK906, a tripeptide antihypertensive agent, was used as a model compound to study some physicochemical properties of peptides and peptide-related compounds. Our results indicate that lyophilization, grinding and melting or storing the samples under conditions of high relative humidity affect chemical stability and crystallinity of FK906. In a preliminary study of lyophilization process design, an extended phase diagram for FK906 in aqueous solution was constructed, and the effects of cooling rate and and heating rate on the glass transition temperatures of lyophilized FK906 and the FK906 solution were investigated. Following lyophilization, the DSC thermogram of FK906 exhibits an endothermic peak whose area is storage temperature- and time-dependent. The endothermic peak shifts to higher temperatures as the heating rate is increased. Our results indicate that the endothermic peak is related to structural change during incubation of lyophilized FK906.