Emergence of Escherichia coli isolates producing conjugative plasmid-mediated DHA-1 β-lactamase in a Korean university hospital

Seven isolates of cefoxitin-resistant Escherichia coli with an inducible phenotype were detected between November 2002 and July 2003 in a Korean hospital. Conjugations were tested by the filter mating method using azide-resistant E. coli J53 as the recipient. All isolates and their transconjugants were tested for broth microdilution minimum inhibitory concentrations, isoelectric focusing (IEF), polymerase chain reaction (PCR) for SHV, TEM, CTX-M and DHA-derived beta-lactamases, and DNA sequencing. XbaI-digested genomic DNA bands of the seven isolates were separated by pulsed-field gel electrophoresis (PFGE). IEF, PCR and sequence analysis revealed that all isolates possessed a blaTEM-1-like and a blaDHA-1 gene. Two isolates also carried the blaCTX-M-14 gene. Transfer of the resistance by conjugation experiments of all seven isolates was successful, suggesting that the blaDHA-1-containing plasmids in the E. coli isolates were self-transmissible. The isolates were recovered from patients in wards or an intensive care unit, all of which had been exposed to beta-lactams before isolation of the DHA-1 producers. Five patterns among the seven isolates were demonstrated by PFGE; sporadic infections with E. coli possessing an inducible beta-lactam resistance phenotype were found. DHA-1 encoded by conjugative plasmids conferred the resistance phenotype. The spread of the DHA-1 producers was due to both clonal spread and horizontal transfer of the resistance gene.

Methylation of the p16(INK4a) promoter region in telomerase immortalized human keratinocytes co-cultured with feeder cells

Human keratinocytes grown in co-culture with fibroblast feeder cells have an extended in vitro lifespan and delayed accumulation of the tumor suppressor protein p16(INK4a) when compared to the same cells grown on tissue culture plastic alone. Previous studies have indicated that human keratinocytes can be immortalized by telomerase activity alone when grown in co-culture with feeder cells, suggesting that loss of the p16(INK4a)/Rb pathway is not required for immortalization. Using two independent human keratinocyte cell strains, we found that exogenous telomerase expression and co-culture with feeder cells results in efficient extension of lifespan without an apparent crisis. However, when these cells were transferred from the co-culture environment to plastic alone they experienced only a brief period of slowed growth before continuing to proliferate indefinitely. Examination of immortal cell lines demonstrated p16(INK4a) promoter methylation had occurred in both the absence and presence of feeder cells. Reintroduction of p16(INK4a) into immortal cell lines resulted in rapid growth arrest. Our results suggest that p16(INK4a)/Rb-induced telomere-independent senescence, although delayed in the presence of feeders, still provides a proliferation barrier to human keratinocytes in this culture system and that extended culture of telomerase-transduced keratinocytes on feeders can lead to the methylation of p16(INK4a).

Methylenetetrahydrofolate reductase A1298C genotypes are associated with the risks of acute lymphoblastic leukaemia and chronic myelogenous leukaemia in the Korean population

Methylenetetrahydrofolate reductase (MTHFR) is a key enzyme involved in folate metabolism, DNA methylation and synthesis. We investigated the association between MTHFR polymorphisms and the risks of acute and chronic leukaemias. MTHFR C677T and A1298C were genotyped in 396 Korean individuals using multiplex polymerase chain reaction/restriction fragment-length polymorphism. They were acute lymphoblastic leukaemia (ALL, n = 89), acute myeloid leukaemia (AML, n = 55), biphenotypic acute leukaemia (n = 12), chronic myelogenous leukaemia (CML, n = 40), and normal controls (n = 200). C677T genotypes were not associated with the risk of each disease. A1298C variants, however, significantly decreased the risks of ALL and CML compared with 1298AA. Odds ratios and 95% confidence intervals of 1298AC and 1298AC + CC were 0.53 (0.31-0.93) and 0.54 (0.31-0.93) in ALL, and 0.34 (0.14-0.80) and 0.40 (0.18-0.89) in CML, respectively, compared with 1298AA. These findings demonstrate that the development of ALL and CML is more dependent on folate status, and more susceptible to DNA instability than that of AML. In addition, A1298C rather than C677T may be a more important genetic risk modifier in leukaemogenesis at least in the Korean population.

Phase II study of the American Brachytherapy Society guidelines for the use of high-dose rate brachytherapy in the treatment of cervical carcinoma: is 45-50.4 Gy radiochemotherapy plus 31.8 Gy in six fractions high-dose rate brachytherapy tolerable?

In 2000, the American Brachytherapy Society (ABS) published incompletely evaluated guidelines for curative chemoradiation and high-dose rate (HDR) brachytherapy for cervical cancer: our aim was to assess guideline tolerability in an Asian population. From 2000, all stage I-IVA cervical carcinoma patients were treated following ABS guidelines. Early disease (FIGO stage I/II <4 cm) received 45 Gy whole-pelvis external-beam radiation (EBRT) at 1.8 Gy/fraction, while advanced-stage disease received 50.4 Gy: no central shielding was used. All patients were planned to receive chemotherapy during EBRT, cisplatin 40 mg/m(2) weekly. All patients received 31.8-Gy HDR brachytherapy (six fractions of 5.3 Gy/fraction) to point A via three-channel applicators. Radiotherapy was completed within 8 weeks. Toxicity scoring used Common Toxicity Criteria. Nineteen of 21 (90.4%) patients (8 early, 13 advanced stage) received planned radiation, and 85.7% received planned chemotherapy. Median follow-up was 24 months (range 9-50 months). Three-year overall survival (S) was 79.1% and disease-free survival (DFS) was 64.8%. S/DFS for early and advanced stage was 85.7%/85.7% and 73.3%/47.1%, respectively. Complete response (CR) was achieved by 85.7% of patients, partial response 14.3%. For those in CR, there were no local failures. Acute cystitis occurred in 23.8%, proctitis 4.8%, and gastroenteritis 47.6%. Late cystitis occurred in 9.5%, gastroenteritis 4.8%, and genitourinary fistula (in the presence of progressive disease) 4.8%. No grade 3/4 treatment-related toxicity occurred. The ABS guidelines were well tolerated and efficacious in our study, although longer follow-up is required. Further studies are warranted to validate safety and efficacy of the recommendations.

Anti-inflammatory effect of jeongshintang through suppression of p38 activation in human astrocytoma, U373MG cells

Jeongshintang (JST) is a Korean herbal prescription, which has been successfully used for cerebral diseases. However, the anti-inflammatory effect of JST on Alzheimer's disease (AD) is still not fully understood. In this study, we investigated the effects of JST in attenuating the inflammatory response induced by interleukin (IL)-1beta plus beta-amyloid [1-42] fragment (A beta) in the human astrocyte cell line, U373MG. The production of IL-6, IL-8, and prostaglandin (PG)E2 was significantly increased by IL-1beta plus A beta (1-42) in a time-dependent manner (P < 0.05). JST significantly inhibited the IL-1beta plus A beta (1-42)-induced IL-6, IL-8, and PGE2 production at 24 h (P < 0.05). Maximal inhibition rate of IL-6, IL-8, and PGE2 production by JST was about 54.40%, 56.01%, and 44.06% respectively. JST (0.01-1 mg/ml) also attenuated the expression of cyclooxygenase (COX)-2 and activation of p38 MAPK induced by IL-1beta and A beta (1-42). These results demonstrated that JST has an anti-inflammatory effect, which might explain its beneficial effect in the treatment of various neurodegenerative diseases such as AD.

APOE epsilon2/epsilon4 polymorphism and cerebral microbleeds on gradient-echo MRI

The association of APOE genotypes with cerebral microbleeds (CMBs) was examined on the basis of the location of CMBs in 414 patients who were admitted primarily because of stroke. With respect to possession of the epsilon2 or epsilon4 allele, the adjusted odds ratio was 1.94 (1.05 to 3.58) for lobar CMBs but 1.21 (0.69 to 2.11) for nonlobar CMBs. This suggests that the pathogenesis of CMBs may differ depending on their location.

Cell-mediated response at the muscle phase of Trichinella pseudospiralis and Trichinella spiralis infections

The cell-mediated response in BALB/c mice infected either by Trichinella pseudospiralis or Trichinella spiralis was compared at days 30-50 post-infection (muscle phase). The former species is non-encapsulated, whereas the latter is encapsulated in host muscles. The pattern of response against the two species was similar. Both species elicited T(H)0 or T(H)1/T(H)2 response, with the last one being dominant. Productions of interferon gamma (IFN-gamma), interleukin (IL)-4 and IL-5 were observed after antigenic restimulation of splenocytes from infected mice. No significant difference was observed between the levels of response to concanavalin A (Con-A) by the splenocytes from both infected and non-infected animals. There was a significant increase in serum IgG(1) and IgG(2a). Flow cytometric analysis revealed a marked proliferative response of splenocytes from infected mice to worm antigens, dominated by B (CD19) lymphoblasts. Only a few helper (CD4+) and cytotoxic (CD8+) T lymphoblasts were present. This was confirmed by an up-regulation of CD69, with a dominant expression on B lymphoblasts. In conclusion, the minimal or lack of intense cellular response against T. pseudospiralis in muscles is likely not due to depression of cell-mediated immunity.

Morphometric analysis of acetabular dysplasia in cerebral palsy

We carried out a morphometric analysis of acetabular dysplasia in patients with cerebral palsy requiring hip surgery using three-dimensional CT. We evaluated 54 hips in 27 patients. The contralateral normal hips of ten patients with unilateral Perthes’ disease were used as a control group. The acetabular defects were assessed qualitatively as anterior, posterior or global. Quantitative assessments were made using three-directional acetabular indices (anterosuperior, superolateral and posterosuperior) and measured by multiplanar reformation, from which we calculated the acetabular volume.

In the qualitative study, posterior defects were most common in the subluxation group whereas global defects predominated in the dislocation group. In the quantitative study, all acetabular indices in both the subluxation and dislocation groups were higher than those in the control group and the superolateral indices showed a tendency to elevation in the dislocation group. The acetabular volume was largest in the control group, smallest in the dislocation group, and intermediate between the two in the subluxation group.

Lower degree of mineralization found in cortical bone of adolescent idiopathic scoliosis (AIS)

A lowered bone mineral density (BMD) was observed in trabecular bone in a significant number of AIS patients. The present study aims at investigating whether lower BMD is a systemic phenomenon, which would also be present in the cortical component of long bone.

SUBJECTS AND METHODS

78 AIS girls (age:15-18y.o) with either moderate (Cobb: 20-40) or severe (Cobb: >40) curve and 44 age-matched controls were recruited. The BMD of the distal region and the mid-shaft of radius were measured with a multi-layer peripheral quantitative computed tomography (pQCT). The trabecular bone and cortical bone BMD and the morphology of mid-shaft were compared.

RESULTS

Both trabecular and cortical BMD in severe AIS group was significantly lower than the control by 8.7% and 1.7% (p<0.05 for both), respectively. However, the cortical bone area of the mid-shaft did not show any differences from the normal control subjects.

DISCUSSION

This study demonstrates a systemic low BMD including the cortical bone. It is suggested that AIS girls may have disturbance in mineralization and ossification during peripubertal growth.

Genetic association study of insulin-like growth factor-I (IGF-I) gene with curve severity and osteopenia in adolescent idiopathic scoliosis

IGF-I has a pivotal role in bone growth and could be one of the putative disease-modifier genes in AIS. Two SNPs in IGF-I gene promoter region were studied for any association with occurrence of AIS and for their effect on the curve severity among AIS.

METHODS

506 AIS girls (Cobb>20 degrees) and 227 age-matched Chinese girls were recruited. The spine (L2-L4) and hip BMD of the subjects were measured by DXA. A subgroup of AIS patients (N=340) who were followed-up to skeletal maturity and the maximum Cobb's angle was recorded. Two SNPs were genotyped by PCR-RFLP (rs5742612 and rs2288377). The chi-square test and one-way ANOVA were used to test the association between genotypes and quantitative parameters, respectively.

RESULTS

No association was between the genotypes and the occurrence of AIS and the BMD of the spine and hip. The allelic frequency of T allele was 0.69 in AIS and control. However, the Cobb's angle was higher in patients with the homozygous T allele (Mean Cobb's angle: 38.1 degrees in TT vs 35.9 degrees in TC vs 33.2 degrees in CC group; p=0.04).

DISCUSSION

Interestingly, IGF-I polymorphism affects the curve severity of AIS though it was not associated with onset of AIS per se. It indicates that IGF-I may be a disease modifying gene. The importance of IGF-I in skeletal growth makes it a good candidate gene which would play a role in the documented association of rapid growth with curve progression in AIS.

Changes in vertebral neural arch morphometry and functional tethering of spinal cord in adolescent idiopathic scoliosis--study with multi-planar reformat magnetic resonance imaging

With the use of multiplanar reformat Magnetic Resonance imaging, AIS patients were found to have significantly reduced pedicle widths on concavity. Pattern of vertebral asymmetry was also exaggerated with smaller pedicle width, length and area on concavity. The cord appeared more roundish and was deviated to the concavity at apical vertebra in AIS. A tethering force might therefore be present on the cord along the transverse axis in AIS, accounted by the relatively fixed position of the exit nerve roots and deviation of the cord from the exit foraminae of the corresponding vertebra.

The role of melatonin receptor 1B gene (MTNR1B) in adolescent idiopathic scoliosis--a genetic association study

Many studies have demonstrated the role of melatonin in the etiology of AIS. Previous studies have shown that there is no evidence of mutations in the melatonin receptor 1A gene in AIS patients. In this study, we have examined the role of melatonin receptor 1B in predisposition for AIS. Using haplotype block tagging technique, a set of tagging SNPs were defined for MTNR1B from the Han Chinese data of the International HapMap project. The association between the tagging of single nucleotide polymorphisms (tSNPs) in MTNR1B region and the occurrence of AIS was studied.

METHOD

473 AIS girls and 311 normal controls were recruited. The age range of the patients was between 10 and 18 years old. The maximum Cobb was recorded at latest follow-up in AIS patients. Three of five tSNPs were studied; they were all located within the coding region of the MTNR1B gene.

RESULTS

There was no significant difference in the genotype or allelic frequencies (AF) of the 3 tSNPs between AIS and controls. In a case-only analysis, no difference in curve severity in AIS patients was found among patients with different genotypes (by one-way ANOVA).

DISCUSSION

The 3 tSNPs showed no association with either the occurrence of AIS or the maximum Cobb angle within AIS girls. Further analysis of the remaining tSNPs within the regulatory region of the MTNR1B gene and other related genes in the melatonin signaling pathway may provide further information on the role of the melatonin in AIS girls.

Tob is a potential marker gene for the basal layer of the epidermis and is stably expressed in human primary keratinocytes

BACKGROUND

Epidermis consists of multiple layers, from the proliferating basal layer to terminal differentiated cornified layers, and these layers are defined by differentiation status. Tob gene product is known to be a member of the BTG antiproliferative protein family. We investigated the expression pattern of Tob gene product to understand the possible role in differentiation of keratinocytes and epidermis.

OBJECTIVES

In this study, we examined the expression of Tob gene product in the primary cultured human keratinocytes and in the in vivo epidermis.

METHODS

The expression of Tob gene product was assessed by Western blotting analysis. Cellular localization of Tob was detected using the green fluorescent protein-tagged Tob cDNA expression construct. In vivo expression of Tob gene product in the epidermis was determined by immunohistochemistry with paraffin sections.

RESULTS

Tob family members are degraded by the ubiquitine-proteasome system triggered by the growth signal. Tob is stably and abundantly expressed in primary cultured human keratinocytes. Furthermore, the expression of Tob in the keratinocytes persists during the differentiation induced by calcium; however, it was not detected in primary cultured fibroblasts. Also, the subcellular localization of Tob is mainly in the cellular membrane in the primary human keratinocytes. We evaluated Tob expression in normal skin, oral mucosa and different diseases, such as psoriasis, X-linked ichthyosis and squamous cell carcinoma (SCC). Using immunohistochemical analysis, we observed that Tob was selectively expressed in the basal layer of X-linked ichythyosis and the hyperproliferative basal layer of psoriasis and oral mucosa as well as in normal epidermis. In SCC, the expression of Tob gene product was relatively decreased.

CONCLUSIONS

Tob is stably expressed in primary human keratinocytes and it is specifically expressed in the basal layer of in vivo epidermis.

Osteopenia: a new prognostic factor of curve progression in adolescent idiopathic scoliosis

BACKGROUND

Studies have shown that 27% to 38% of girls with adolescent idiopathic scoliosis have systemic osteopenia. The aim of this study was to investigate whether osteopenia could serve as one of the important prognostic factors in predicting curve progression.

METHODS

A prospective study was performed in 324 adolescent girls with adolescent idiopathic scoliosis who had a mean age of thirteen and a half years. Bone mineral density of the spine and both hips was measured at the time of the clinical diagnosis of scoliosis. All patients were followed longitudinally until skeletal maturity or until the curve had progressed > or =6 degrees . The univariate chi-square test and stepwise logistic regression were used to predict the prevalence of curve progression, and a receiver operating characteristic curve was plotted.

RESULTS

The overall prevalence of curve progression was 50%. The prevalence of osteopenia at the spine and hips was 27.5% and 23.1%, respectively. A larger initial Cobb angle (odds ratio = 4.6), a lower Risser grade (odds ratio = 4.7), premenarchal status (odds ratio = 2.5), osteopenia in the femoral neck of the hip on the side of the concavity (odds ratio = 2.3), and a younger age at the time of diagnosis (odds ratio = 2.1) were identified as risk factors in predicting curve progression. A predictive model was established, and the area under the receiver operating characteristic curve of the model was 0.80 (p < 0.01).

CONCLUSION

Osteopenia may be an important risk factor in curve progression. The measurement of bone mineral density at the time of diagnosis may serve as an additional objective measurement in predicting curve progression in adolescent idiopathic scoliosis. The bone mineral density-inclusive predictive model may be used in treatment planning for patients with adolescent idiopathic scoliosis who are at high risk of curve progression.

Genetic polymorphisms of OPG, RANK, and ESR1 and bone mineral density in Korean postmenopausal women

To evaluate the effects of genetic polymorphisms of OPG, RANK, and ESR1, which regulate osteoclastogenesis, on bone mineral density (BMD), a cross-sectional study was conducted in 650 Korean postmenopausal women. BMDs of the distal radius and the calcaneus were measured by dual energy X-ray absorptiometry (DXA). Genetic polymorphisms of OPG 163 A > G, 1181 G > C; RANK 421 C > T, 575 T > C; and ESR1 1335 C > T, 2142 G > A were determined by matrix-assisted laser desorption/ionization-time of flight (MALDI-ToF) mass spectrometry. The differences between the BMDs of the genotypes of OPG, RANK, and ESR1 were analyzed by multiple linear regression model adjusted for age and body mass index. Women with the OPG 1181 CC genotype had higher BMDs at the distal radius (7%) and calcaneus (10%) than those with the GG genotype; and these differences were statistically significant (P = 0.001 and P = 0.007, respectively). A significant association was also observed between RANK 575 T > C and calcaneus BMD (P for trend = 0.017). No significant association was observed between BMDs and the polymorphisms of ESR1. The association between OPG 1181 G > C and BMD was profound in subjects with the RANK 575 TT or ESR1 2142 GG genotypes; women with OPG 1181 CC had higher BMDs at the distal radius (11%) and calcaneus (11%) than those with OPG 1181 GG only in women with RANK 575 TT genotype (P = 0.002 and P = 0.021, respectively). These results suggest that OPG genetic polymorphisms, especially with the RANK 575 TT or ESR1 2142 GG genotypes, are related to low BMD in postmenopausal Korean women.

Effects of different levels of dietary supplemental selenium on performance, lipid oxidation, and color stability of broiler chicks

This study examined the effects of supplemental dietary selenium on growth performance, lipid oxidation, and color stability of broiler chicks. Male broiler chicks (Arbor Acres, 1 d old, total 900 chicks) were randomly assigned to 6 pens containing 30 chicks each, corresponding to each of 6 dietary treatments. Six different diets were supplied to the chicks from 3 to 6 wk of age. After 42 d of feeding, all the broilers were slaughtered conventionally at a slaughtering plant. The carcasses were packed in polyethylene bags in a manner similar to that used for retail trade and stored for 12 d at 4 degrees C. Body weight and feed efficiency were not affected by dietary selenium levels, and no adverse effect on growth was observed during the experimental period. The dietary selenium and alpha-tocopherol levels did not affect surface meat color or level of metmyoglobin accumulation. Lipid stability was improved by supplementation with 100 IU of alpha-tocopherol (P < 0.05). Dietary selenium supplementation at 8 ppm in combination with 100 IU of alpha-tocopherol, however, was more effective in reducing lipid oxidation compared with 100 IU of alpha-tocopherol/kg feed only (P < 0.05). Supplementation with 100 IU of alpha-tocopherol affected cholesterol oxidation product levels on d 7 and 12, but selenium supplementation did not have an additional effect on the reduction of cholesterol oxidation products. Therefore, an increase in the dietary selenium from 1 to 8 ppm revealed only minor improvements in the oxidative stability of chicken meat during refrigerated storage.

Antibacterial and antifungal activity of pinosylvin, a constituent of pine

The antibacterial and antifungal activities of pinosylvin (3,5-dihydroxy-trans-stilbene), a constituent of pine, were studied and compared with those of resveratrol (3,5,4'-trihydroxy-trans-stilbene). Pinosylvin exhibited more potent growth inhibitory activity against Candida albicans and Saccharomyces cerevisiae.

Bioregeneration of powdered activated carbon in the treatment of alkyl-substituted phenolic compounds in simultaneous adsorption and biodegradation processes

The role of bioregeneration process in renewing the adsorbent surface for further adsorption of organics during simultaneous adsorption and biodegradation processes has been well recognized. The extent of bioregeneration of powdered activated carbon (PAC) as an adsorbent loaded with phenol, p-methylphenol, p-ethylphenol and p-isopropylphenol, respectively, in the simultaneous adsorption and biodegradation processes were quantitatively determined using oxygen uptake as a measure of substrate consumption. Bioregeneration phenomenon was also evaluated in the simultaneous adsorption and biodegradation processes under sequencing batch reactor (SBR) operation to treat synthetic wastewater containing 1200 mg l(-1) phenol and p-methylphenol, respectively. The SBR systems were operated with FILL, REACT, SETTLE, DRAW and IDLE periods in the ratio of 4:6:1:0.75:0.25 for a cycle time of 12 h. The results show that the percentage of desorption from loaded PAC decreased in the order phenol>p-methylphenol>p-ethylphenol>p-isopropylphenol. For the treatment of phenol and p-methylphenol in the SBR reactors, respectively, the simultaneous adsorption and biodegradation processes were able to produce a consistent effluent quality of COD < or = 100 mg l(-1) when the applied PAC dosage was 0.115 and 0.143 g PAC per cycle, respectively. When no further PAC was added, the treatment performance deteriorated to that of the case without PAC addition after 68 and 48 cycles of SBR operation, respectively, for phenol and p-methylphenol. This observation is consistent with the greater extent of bioregeneration for phenol-loaded PAC as compared to p-methylphenol-loaded PAC.

Application of remote monitoring and automatic control system using neural network for small wastewater treatment plants in Korea

For this study, an automatic control system has been developed by using a neural network and internet-based remote monitoring system for efficient operation of plants that have a serious variance of influent loading and have difficulties in appropriate maintenance, just like small wastewater treatment plants in Korea. In the control algorithm, ORP was used as the main sensor for control. At the point where the ORP value was judged to reach the "nitrate knee" of denitrification and phosphorus release, ORP indicated the state of lower saturation read by the neural network and then changed the operating condition from the reduction state to the oxidation state. For example, if ORP indicates the state of higher saturation at the point of "nitrogen breakpoint" or "ammonia valley" of nitrification, the neural network reads it and cuts off the oxygen supply and mixing. The dORP data have been used as one of the main input for the neural network. After the operation of lab-scale cyclic aeration process using an automatic control system, it has been found that regardless of loading variance, more than 95% of organic matters and more than 60% of nitrogen and phosphorus have been removed. Assuming that an internet-connected computer and a basic web browser are available, this study has developed a remote monitoring system that can monitor the operating status of small plants or any troubles with them.

Analysis of genes responding to ultraviolet B irradiation of HaCaT keratinocytes using a cDNA microarray

BACKGROUND

Ultraviolet (UV) B irradiation causes many important biological changes in skin, which lead to pathophysiological alterations of the homeostatic environment.

OBJECTIVES

To gain more insight into the molecular events provoked by UVB irradiation, we performed cDNA microarray analysis.

METHODS

Immortalized HaCaT keratinocytes were irradiated with a high cytotoxic dose of UVB (50 mJ cm(-2)), and total RNA was isolated. Fluorescently labelled probes were prepared by reverse transcription and were hybridized with cDNA microarray slides made using 840 cDNA clones.

RESULTS

Time-course cDNA microarray analysis revealed the global gene expression profile after UVB exposure. Of 840 genes tested, 192 genes showed changes in their expression levels at one or more of four time points. The genes were clustered into four groups according to their expression patterns in a self-organizing maps analysis. Classification of these genes into nine functional categories revealed that UVB irradiation affected several biological processes. The genes that were first upregulated and then returned to normal levels included several genes related to the inhibition of cell growth and the proteasome pathway. Conversely, the expressions of many genes involved in the cytoskeleton, signal transduction, metabolism and transcription were first downregulated or unchanged and then upregulated later, reflecting the recovery of UVB-damaged cellular activities.

CONCLUSIONS

These results demonstrate the complexity of the transcriptional profile of the UVB response, and provide a basis for the global characterization of UV-regulated gene expression.

Ameloblastoma in the Hong Kong Chinese. Part 2: systematic review and radiological presentation

OBJECTIVES

The aim of this part of the study was to determine the radiological presentation on conventional radiographs of central ameloblastomas in the Hong Kong Chinese and compare them with other reported series by a systematic review (SR).

METHODS

The study had two elements, that of a complete series of all ameloblastomas presenting at a major Chinese maxillofacial surgical unit and a SR. The files of the Department of Oral and Maxillofacial Surgery of the University of Hong Kong between 1989 and 2000 were reviewed for ameloblastoma cases. The relevant literature was identified by electronic databases, review of citation lists and handsearching of key journals. The principal selection criterion was that the study should represent a complete collection of cases.

RESULTS

Only 13 reports gave any radiological details. The present study of the Hong Kong Chinese contained 61 cases. With the exception of radiodensity and shape of radiolucency, the majority of the 13 other reports did not record the other radiological features that could be important in the diagnosis. The present study agreed with the synthesis of the 13 reports with regards to complete radiolucency and cortication of ameloblastomas, but disagreed with regards to other important features. The present study had a significantly higher proportion of unilocular lesions, better marginal definition, and more frequent perforation of the cortex and buccolingual expansion. Nine of the ten maxillary lesions straddled both anterior and posterior sextants with four crossing the midline, whereas only 13 of the 51 mandibular cases affected both sextants, of which eight crossed the midline. The unicystic form, which was most prevalent, appeared significantly more frequently as unilocular radiolucencies in comparison with the non-unicystic forms. The frequencies of unicystic forms and unilocular presentations were significantly greater in the young. The lesions in the young were significantly sited solely in the posterior sextant. The lower border of the mandible was reached and affected by ameloblastoma in 36 cases in the present report. It was displaced and thinned in 15 cases whereas in just five it was at least partially undisplaced with the lesion expanding down past it either buccally or lingually to it. The unicystic form was significantly more associated with root resorption, tooth displacement and crowns of unerupted teeth.

CONCLUSIONS

Radiologically, ameloblastomas in the Hong Kong Chinese differ significantly with regards to many features. This can be in part explained by the higher proportion of the unicystic form.

Ameloblastoma in the Hong Kong Chinese. Part 1: systematic review and clinical presentation

OBJECTIVES

The aim of Part 1 of this study was to determine the clinical presentation of central ameloblastomas in the Hong Kong Chinese and to compare them with other reported series by a systematic review (SR).

METHODS

The study had two elements, that of a complete series of all ameloblastomas presenting at a major Chinese maxillofacial surgical unit as well as a SR. The files of the Department of Oral and Maxillofacial Surgery of the University of Hong Kong between 1989 and 2000 were reviewed for ameloblastoma cases. The relevant literature was identified by electronic databases, review of citation lists and hand searching of key journals. The principal selection criterion was that the study should represent a complete collection of cases.

RESULTS

Fifty-three published series of cases were included in the SR. They generally reported little more than sex, mean age and range, and affected jaw. Only 16 studies considered recurrence. Sixty-one cases of ameloblastoma were identified in the present study. There were 30 males and 31 females, contrary to the predilection for males in other reports. Eighty-four percent of cases were found in the mandible, agreeing with the SR. The mean age at first presentation was 30.5 years, lower than that of the SR; only a Korean report and a small Bangladeshi report showed younger presentation. The present report had the shortest period between first becoming aware of the lesion and seeking treatment; this period was significantly shorter for younger patients. Although the present study was in agreement with the SR with regard to swelling, this study reported a significantly higher proportion of patients presenting with pain.

CONCLUSION

Although the presentation of ameloblastoma within this Chinese community was broadly similar to that observed in other populations, it differed in a number of important respects. It had a younger age at first presentation than many other communities, including other Orientals; it was associated with a shorter period between first becoming aware of the lesion and seeking treatment, particularly in the young; and it was more frequently associated with pain than in the SR.

Improving the diagnosis related grouping model's ability to explain length of stay of elderly medical inpatients by incorporating function-linked variables

INTRODUCTION

This study first aimed to determine the adequacy of the Diagnosis Related Grouping (DRG) model's ability to explain (1) the variance in the actual length of stay (LOS) of elderly medical inpatients and (2) the LOS difference in the same cohort between the departments of Geriatric Medicine (GRM) and General Medicine (GM). We then looked at how these explanatory abilities of the DRG changed when patients' function-linked variables (ignored by DRG) were incorporated into the model.

MATERIALS AND METHODS

Basic demographic data of a consecutively hospitalised cohort of elderly medical inpatients from GRM and GM, as well as their actual LOS, discharge DRG codes [with their corresponding trimmed average length of stay (ALOS)] and selected function-linked variables (including premorbid functional status, change in functional profile during hospitalisation and number of therapists seen) were recorded. Beginning with ALOS, function-linked variables that were significantly associated with LOS were then added into two multiple liner regression models so as to quantify how the functional dimension improved the DRGs' abilities to explain LOS variances and interdepartmental LOS differences. Forward selection procedure was employed to determine the final models. For the interdepartmental analysis, the study sample was restricted to patients who shared common DRG codes.

RESULTS

114 GRM and 118 GM patients were studied. Trimmed ALOS alone explained 8% of the actual LOS variance. With the addition of function-linked variables, the adjusted R2 of the final model increased to 28%. Due to common code restrictions, the data of 79 GRM and 78 GM patients were available for the analysis of interdepartmental LOS differences. At the unadjusted stage, the median stay of GRM patients was 4.3 days longer than GM's and with adjustments made for the DRGs, this difference was reduced to 3.9 days. Additionally adjusting for the patients' functional features diminished the interdepartmental LOS discrepancy even further, to 2.1 days.

CONCLUSION

This study demonstrates that for elderly medical inpatients, the incorporation of patients' functional status significantly improves the DRG model's ability to predict the patients' actual LOS as well as to explain interdepartmental LOS differences between GRM and GM.

Pseudobasophilia as an erroneous white blood cell differential count with a discrepancy between automated cell counters: report of two cases

We report two cases that showed erroneous white blood cell differential counts by automated cell counters. Each case showed an interesting discrepancy of differential count between cell counters, and marked pseudobasophilia was observed by one of the two counters. The first patient was a 44-year-old female who suffered from multiple myeloma for more than one and a half years. Increased myeloma cells (43%) in peripheral blood were counted as basophils by the ADVIA 120, and as monocytes by SE-9000, respectively. The second patient was a 72-year-old female diagnosed as having chronic myelomonocytic leukemia. Dysgranulopoietic neutrophils (50%) and monocytes (31%) were increased in the peripheral blood. Dysgranulopoietic neutrophils were counted as basophils by STKS. In contrast, about half of the increased monocytes were counted as neutrophils by the ADVIA 120. These interesting findings highlight the importance of microscopic examination of the blood film in routine laboratory practice, and automated cell counters, especially for the hematologic patients, cannot completely substitute for it. These results also imply that at least some subpopulations with different membrane or cytoplasmic properties may exist even in the similarly classified cells.