Discovery of a novel HLA-B*51 variant, B*51:112, in a Taiwanese bone marrow donor and identification of the plausible HLA haplotype in association with B*51:112

The sequence of B*51:112 is identical to the sequence of B*51:01:01 in exons 2, 3 and 4, except the nucleotides at positions 206 (C→A) and 213 (C→G). The nucleotide replacement caused one amino acid substitution at residue 45 (T→K). The plausible HLA-A, -B and -DRB1 haplotype in association with B*51:112 may be deduced as HLA-A*02-B*51:112-DRB1*12. The generation of B*51:112 was probably as the result of a DNA recombination event where B*40:01:01 acted as a sequence donor donating a segment of the DNA sequence to the recipient sequence B*51:01:01. The donor carrying B*51:112 was a Minna Taiwanese whose ancestor came to Taiwan from the southern region of China.

Identification of two novel HLA-A*02 variants, A*02:319 and A*02:01:64, in two Taiwanese marrow stem cell donors by sequence-based typing

We report here two novel variants of HLA-A*02 allele, A*02:319 and A*02:01:64, discovered in two Taiwanese unrelated volunteer bone marrow donors by sequence-based typing (SBT) method. The DNA sequence of A*02:319 is identical to A*02:07 in exons 2 and 3 but varies with one nucleotide at codon 9 (TTC->TCC). The variation caused one amino acid substitution at residue 9 (F->S). On the other hand, the DNA sequence of A*02:01:64 is identical to the sequence of A*02:01:01:01 in exons 2 and 3 except a silent mutation at codon 114 (CAC->CAT). The probable HLA-A, HLA-B and HLA-DRB1 haplotypes in association with A*02:319 and A*02:01:64 were deduced as A*02:319-B*46:01-DRB1*04 and A*02:01:64-B*38:02-DRB1*16:02, respectively.

Detection of two HLA-B*27 alleles, B*27:25 and B*27:86, in two Taiwanese blood donors by sequence-based typing

We report here two HLA-B*27 alleles, B*27:86 and B*27:25, found in two Taiwanese blood donors. The new sequence of B*27:86 is identical to B*27:04:01 in exons 2 and 3, except at nucleotide 602 (A → G) in exon 3. The nucleotide change caused an amino acid substitution from E to G at amino acid residue 177. The sequence of B*27:25 is identical to B*27:04:01 in exons 2, 3, 4, 5, 6 and 7 except at nucleotides 538, 539, 559 and 560 in exon 4. The nucleotide changes caused amino acid substitutions from L to W and from E to L at residues 156 and 163, respectively. The generation of B*27:86 was probably resulted by a point mutation while the generation of B*27:25 may have been derived from a sequence recombination event between B*46:01:01 and B*27:04:01. The probable HLA-A, -B and -DRB1 haplotypes in association with B*27:86 and B*27:25 may be deduced as A*11:53-B*27:86-DRB1*12 and A*11:01-B*27:25-DRB1*04:05, respectively.

Discovery of two novel HLA-B alleles, B*46:13:03 and B*15:189, in two Taiwanese volunteer bone marrow donors by sequence-based typing

We report here two novel HLA-B alleles, B*46:13:03 and B*15:189, discovered in two Taiwanese volunteer bone marrow donors. The sequence of B*15:189 has a nucleotide sequence possibly derived from a recombination event between HLA-B*39:01:01 and B*15:01:01:01, while the origin of the sequence B*46:13:03 was less obvious to postulate, considering the low frequency of B*46:13 in the general population and the silent mutations involved. Our report here adds further HLA polymorphism to the growing lists of HLA-B*46 and HLA-B*15 and provides an additional HLA information for donor search programme for patients undergoing transplant.

Oriental HLA-A*11:90 detected in a Taiwanese cord blood sample and the haplotype in association with A*11:90 allele

We report here an HLA-A allele, A*11:90, found in a Taiwanese cord blood sample using DNA sequence-based typing (SBT) protocol after observing an anomalous reaction pattern in a sequence-specific oligonucleotide (SSO) typing exercise. The sequence of A*11:90 is identical to A*11:01:01, the most predominant A*11 variant in Taiwanese, in exon 2 but differs from A*11:01:01 in exon 3 by two nucleotide substitutions at codon 163 (c.487C>G and c.488G>A), resulting R163E. In comparison with the sequence of A*11:02:01, the second most predominant subtype of A*11 in Taiwanese A*11:90 has one nucleotide difference at codon 19 (c.55A>G) in exon 2 resulting K19E and two nucleotides variations at codon 163 (c.487C>G and c.488G>A) in exon 3 resulting R163E. HLA-A*11:90-B*40:02-DRB1*11:01 is the deduced probable HLA haplotype in association with A*11:90. The generation of A*11:90 is thought to involve a DNA recombination event between alleles A*11:01:01 and A*80:01 where A*80:01 donated a fragment of the DNA sequence (from n.t. 487 to n.t. 497) to the recipient sequence of A*11:01:01.

Detection of two HLA-A alleles, A*31:30 and A*26:20, in two Taiwanese volunteer bone marrow donors by sequence-based typing

We here report detection of a novel sequence of HLA-A*31:30 and a confirmatory sequence of HLA*26:20 from two Taiwanese individuals. The sequence of A*31:30 is identical to that of A*31:01:02 in exons 2 and 3, except one nucleotide (n.t.) substitution c.539T > G resulting in p.Leu180Trp. The sequence of A*26:20 is identical to A*26:01:01 in exons 2 and 3, except a segment of the sequence from n.t. 78 to n.t.102. The mismatched sequence segment is identical to a sequence segment of A*02:03:01, suggesting that the formation of A*26:20 was resulted from a DNA recombination event between A*26:01:01 and A*02:03:01 sequences. A*26:20 differs from A*26:01:01 with c.98A > T resulting in p.Tyr33Phe.

Identification of a novel HLA-DQB1 allele, DQB1*0326, in a College of American Pathologists 2009 survey specimen

We identified a novel DQB1*0326 allele from a proficiency test sample provided by the College of American Pathologists (CAP) medical society. This novel DQB1 allele was unexpectedly discovered by sequence-based typing method in an attempt to resolve a discrepant typing result between the CAP survey report and our laboratory report. This novel DQB1 allele is most similar to DQB1*030302 and DQB1*0311. DQB1*0326 has a nucleotide substitution resulting an amino acid change when compared with DQB1*030302 (M to L) and it differs from DQB1*0311 by one nucleotide variation causing an amino acid replacement (A to D).

Green fabrication of agar-conjugated Fe3O4 magnetic nanoparticles

Magnetic nanoparticles are of great interest both for fundamental research and emerging applications. In the biomedical field, magnetite (Fe(3)O(4)) has shown promise as a hyperthermia-based tumor therapeutic. However, preparing suitable solubilized magnetite nanoparticles is challenging, primarily due to aggregation and poor biocompatibility. Thus methods for coating Fe(3)O(4) NPs with biocompatible stabilizers are required. We report a new method for preparing Fe(3)O(4) nanoparticles by co-precipitation within the pores of agar gel samples. Permeated agar gels were then dried and ground into a powder, yielding agar-conjugated Fe(3)O(4) nanoparticles. Samples were characterized using XRD, FTIR, TGA, TEM and SQUID. This method for preparing agar-coated Fe(3)O(4) nanoparticles is environmentally friendly, inexpensive and scalable.

Detection of a rare Caucasoid HLA-DRB1*0337 in a Taiwanese bone marrow donor using sequence-based typing method

We here describe the identification of HLA-DRB1*0337, using sequence-based typing (SBT) method, in a Taiwanese bone marrow donor intrigued by a casual curiosity on the donor's racial background. On high-resolution sequence-specific primer (SSP) typing we observed misleading reaction patterns due to similarity of DNA sequences in the exon 2 of DRB1*0301, *0317, *0337 and *1139. When encountering rare alleles in HLA typing, it is important to pay extra attentions to avoid pitfalls and shortcomings of SSP typing kits routinely used and bear in mind that constant up-dating of high-resolution SSP typing kits to be able to distinguish newly reported alleles. SBT may be considered as a back-up HLA typing method to confirm rare alleles.

A novel HLA-B allele, B*5214, detected in a Taiwanese volunteer bone marrow donor using a sequence-based typing method

HLA-B*5214, a novel rare allele of HLA-B*52 variant, was found in a Taiwanese volunteer bone marrow donor by sequence-based typing method. The sequence of B*5214 is identical to that of B*520101 in exon 2 but differs from B*520101 in exon 3 at nucleotide positions 419 A-->T and 435 A-->G. Alteration of these two nucleotides resulted an amino acid substitution at amino acid residue 116 Y-->F ( TAC-->TTC) and a silent exchange at residue 121 K-->K (AAA-->AAG).

Identification of a novel HLA-A allele, A*1131, in a Taiwanese

Here we report the identification and sequence analysis of a new HLA-A11* variant, A*1131 allele, found in a Taiwanese volunteer bone marrow donor. The novel A*11 variant is identical to A*1125 in exon 2 but differs from A*1125 in exon 3 by one nucleotide substitution at position 527 causing an amino acid change at codon 152 E-->V (GAG-->GTG). In comparison with HLA-A*110101, allele A*1131 has three nucleotide differences in exon 3: 527 C-->T, 538 C-->T and 539 A-->T leading to two amino acid variations at residues 152 A-->V and 156 Q-->L.

Unrelated haematopoietic stem cell transplantation in Taiwan and beyond

Since its inception in October 1993, the world-renowned Buddhist Tzu Chi Marrow Donor Registry has facilitated more than 1800 cases of stem cell donations for patients in 27 countries to date. Under the auspices of the Buddhist Tzu Chi Stem Cells Center (BTCSCC), the Registry (> 310,000 donors) offers, on average, one case of stem cell donation every day to national or international transplantation community. The accomplishment of the Registry stems from the philosophy and spirit of giving without reward that was inspired by its founder Dharma Master Cheng Yen, the Samaritan devotions of selfless voluntary stem cell donors and the efforts from a dedicated network of volunteer workers. Demographically speaking, slightly less than one third of the donations are provided to domestic patients and the rest to mainland China and countries in Asia, North America, Europe, Middle East, Oceania, and South Africa. While most of the patients belong to the Oriental ethnic group, a few of the patients are non-Oriental. In addition to the Registry, a non-profit umbilical cord blood (UCB) bank is operating since 2002 to provide a complimentary role for patients unable to identify appropriate bone marrow stem cell donors in the Registry in time. To date, with an inventory of over 12,000 units of UCB cryopreserved in the Tzu Chi Cord Blood Bank, 47 units have been employed in 37 cases of transplantation for both paediatric and adult patients domestically and internationally. The fact that Buddhist Tzu Chi Marrow Donor Registry and Cord Blood Bank are established and operating without governmental financial support is unique and special. To facilitate haematopoietic stem cells to its domestic patients experiencing financial burdens, the BTCSCC offers financial aids to the underprivileged for their medical relief. This humanitarian approach and compassion is definitely a role model for many countries in the world.

Detection of a novel HLA-B27 allele, B*2740, in Taiwanese volunteer bone marrow donors by sequence-based typing: curiosity rewarded

We report here a novel HLA-B allele, B*2740, discovered in Taiwanese volunteer marrow donors. The new sequence has nucleotide variation at position 527 (T-->A) as compared to B*2708. The nucleotide change caused an amino acid substitution from valine (V) to glutamic acid (E) at codon 152. Since B*2740 carries sequence confers to HLA-Bw6 public epitope we believe that this novel B*27 allele might have been generated from a gene conversion involving a Bw4-specific allele (probably B*2704) and a Bw6-specific allele.

Determination of HLA-A, -B and -DRB1 haplotypes based on allelic homozygosity data in selected bone marrow donors of the Taiwanese marrow donor registry

From 120 unrelated Taiwanese marrow stem cell donors with allelic homozygosities at human leucocyte antigen (HLA)-A, -B and -DRB1 loci, we determined 85 distinguishable haplotypes. Using the predetermined haplotype data, we deduced 418 haplotypes from 1903 unrelated individual stem cell donors selected for HLA confirmatory test. Eighteen of the 20 (90%) most frequently observed haplotypes determined in Asian Americans using computer prediction were found in this study. In comparison with haplotypes determined by maximum likelihood algorithm in Korean population, 18 of the 29 (62.07%) Korean haplotypes with a frequency over 0.5% were also among the haplotypes determined in this investigation. Randomized family studies confirmed that over 50% of the haplotypes observed in the families were among the haplotypes deduced based on allelic homozygosity, suggesting that proportionally additional haplotypes can be determined as the number of donors being studied is increased. Haplotypes carrying low incidence allele characteristics of Taiwanese were also observed in this study. This established haplotype information will be beneficial for patients searching for stem cell donors in our registry domestically and internationally.

Sequence-based typing of a novel HLA-DRB1*04 allele, DRB1*0461, in a Taiwanese volunteer marrow donor

We report here a novel HLA-DRB1 allele, DRB1*0461, discovered in a Taiwanese volunteer marrow donor. The new sequence has nucleotide variation at positions 260 (C-->A) and 261 (C-->G), i.e. codon 58, as compared to DRB1*0408. Nucleotide change caused an amino acid substitution from alanine to glutamic acid. We believe that the gene conversion took place between DRB1*0405 and DRB1*1101 based on sequence homology and gene frequency in population studies. In comparison to DRB1*0405, DRB1*0461 has two amino acid changes at codons 57 and 58. Amino acid residue substitution at position 57 may affect peptide-binding environment at pocket P9 of the antigen-binding groove of the MHC molecule. This would have potential effect in peptide binding as well as in T-cell recognition, which could have clinical significance in bone marrow and organ transplantations.

Discovery of HLA-DRB1*0331 in a Taiwanese marrow donor and the importance of sequence-based typing in a rare or previously unrecognized allele

We describe here a novel HLA-DRB1* allele, DRB1*0331, observed from a Taiwanese bone marrow donor using DNA sequence-based typing (SBT) method. The 'new' allele differs from DRB1*0306 and DRB1*0325 by one nucleotide at positions 196 and 227, respectively. Nucleotide mutations caused amino acid substitutions from N to Y at codon 37 and from F to Y at codon 47, as compared with amino acid sequence encoded by the DRB1*030101 allele. The donor was first typed as DRB1*0403/0406/0439/0441/0446/0451/0452 (NMDP code DRB1*04XX) and DRB1*0304/0323/0325 (NMDP code DRB1*03APDA) by sequence-specific oligonucleotide (SSO) typing kit. Subsequent typing of the donor by high-resolution sequence-specific primer (SSP) protocol indicated DRB1*0403 and DRB1*0306. The anomalous result of DRB1*03 was resolved by SBT and recognized as DRB1*0331. We concluded that SSP or SSO alone may mistype a precedent unrecognized allele and that two different typing techniques or SBT may have to be employed to safe guard true HLA typing when rare alleles are encountered at the first time.

Endoscopic submucosal dissection for the treatment of intraluminal gastric subepithelial tumors originating from the muscularis propria layer

BACKGROUND AND STUDY AIMS

Subepithelial tumors of the stomach used to be considered as benign, but they do have malignant potential, especially when they originate from the muscularis propria layer. The aims of this study were to determine the feasibility of endoscopic submucosal dissection (ESD) for the removal of subepithelial tumors from the muscularis propria layer and to evaluate the efficacy and safety of ESD for this indication.

PATIENTS AND METHODS

A total of 12 lesions in 11 patients were eligible for inclusion in the study during the period between December 2004 and February 2006. ESD using an insulated-tip knife was used to remove gastric subepithelial tumors from the muscularis propria where this was possible. Endoscopic mucosal resection using a suction and cap method ("EMR-c") was used to obtain a sufficiently large specimen for tissue diagnosis if complete resection by ESD was not possible.

RESULTS

Nine tumors were resected completely by ESD (success rate 75 %). The mean tumor size as determined by endoscopic ultrasound as 20.7 mm (range 6 - 40 mm). The histological diagnosis was gastrointestinal stromal tumor for eight lesions and leiomyoma for four tumors. The mean operation time was 60.9 minutes (range 20 - 170 minutes), and the average blood loss was 30 ml. No patient developed perforation or massive hemorrhage requiring surgical treatment, and there were no other immediate postprocedure complications.

CONCLUSIONS

ESD can be used for the resection of intraluminal gastric subepithelial tumors and could replace treatment by surgical resection in some cases. EMR-c is an alternative method that can be used to obtain sufficient tumor tissue for histological diagnosis if complete resection by ESD fails.

Maternal anxiety about prenatal screening for group B streptococcus disease and impact of positive colonization results

OBJECTIVE

Universal screening for colonization by group B streptococcus (GBS) is the recommended strategy to reduce incidence of colonization in newborns and prevent neonatal GBS-related disease. This study was designed to assess maternal anxiety levels about prenatal screening and psychological impact of positive colonization test results.

METHODS

A total of 71 women who screened positively for GBS colonization and 112 screen-negative women (controls) were recruited. Anxiety levels were measured by the Spielberger State Trait-anxiety Inventory just before the GBS screening test, 1-week after testing, and 1-week after delivery. After delivery of their infants, all participants were asked to respond with a Likert scale line about attitudes toward being tested for GBS colonization.

RESULTS

Women with GBS colonization reported significantly greater psychological distress on state-anxiety scores after the full report was received. The trait- and state-anxiety scores before GBS screen testing and after delivery did not differ between the groups. Both groups of women were strongly positive about being screened for GBS in the current pregnancy and in future pregnancies.

CONCLUSION

Women with GBS colonization did not have a sustained increase in anxiety; therefore, clinician concerns about causing maternal anxiety should not be an impediment to test for GBS.

Polymorphism of HLA-B27 in Taiwanese Chinese

Heterogeneity of HLA-B27 is represented by a family of 24 closely related alleles/subtypes. Frequency and disease association of these alleles with spondyloarthropathies differ among ethnic groups. Accurate investigation of frequencies of alleles is often hindered by the size and demographic region of sample tested. With an ever-increasing number of B27 alleles being discovered, it is becoming imperative to establish disease association of each individual alleles and its biological importance. In a large number of normal healthy Taiwanese Chinese individuals (75,777) tested nationally, over a period of five years, in a single immunogenetics centre, we found additional B27 subtypes not revealed in a previous Taiwanese Chinese population study. The subtypes found in Taiwanese Chinese and the frequencies of each of the subtypes are reported.

Serological identification of a non-HLA antigen in Oriental populations

In a routine HLA antibody screening cross-match test using the complement-mediated lymphocytotoxicity (LCT) assay, we discovered an antibody, in a transfused Caucasian woman, recognizing an Oriental restricted antigen that does not appear to be associated with the human leukocyte antigen (HLA) system. The distribution of this 'novel' antigen in Oriental populations and its frequency in the Taiwanese Chinese population are reported.

Recognition of HLA-A*0248 in a Chinese donor

HLA-A*0248, a rare allele originally found in an individual of Filipino background, was detected in a Chinese donor. We confirmed the novel sequence and analysed its serological reaction pattern. The exon 2 sequence of A*0248 was apparently generated in a gene conversion event with an A2 gene, receiving a sequence segment comprising codons 56 to 74 from an A*24 donor gene. Serological typing showed a clear-cut A2 reaction pattern, indicating that the three amino acid positions 62, 65 and 74, are probably not a critical part of the A2 epitope. Our typing experience also demonstrated that different typing technologies often complement each other in fine HLA typing.

Short-term ceftriaxone therapy for treatment of severe non-typhoidal Salmonella enterocolitis

AIM

To evaluate the clinical efficacy of a short-course ceftriaxone therapy in the treatment of paediatric patients with severe non-typhoidal Salmonella enterocolitis.

METHODS

During a 1 y period, all paediatric patients who were suspected having Salmonella enterocolitis by the presentation of bloody and/or mucoid diarrhoea with or without fever were eligible for the study. Patients with either negative stool cultures or bacteraemia were excluded. Severe enterocolitis was defined as a bloody and/or mucoid diarrhoea associated with high fever persisting for longer than 48 h and signs of moderate or severe dehydration. The patients with severe enterocolitis were assigned to treatment with ceftriaxone (50 mg kg(-1) d(-1)) for 3-5 d, while the rest were given supportive treatment only. Before treatment all study patients received blood testing for white blood cell (WBC) count, C-reactive protein (CRP) level and blood culture. The duration of the fevers was recorded. Patients were followed up after clinical recovery for the possibility of relapse.

RESULTS

Seventy-three patients with culture-confirmed Salmonella enterocolitis without bacteraemia were analysed. The duration of fever was longer in severe cases who were treated with ceftriaxone than those who were not. However, rapid defervescene was found after short-course ceftriaxone therapy in those patients with severe enterocolitis. CRP was significantly higher in severe cases. There was no significant difference in the WBC count between the two groups of patients. No relapse was found in these patients.

CONCLUSION

High CRP, prolonged high fever and signs of moderate or severe dehydration appear appropriate to define severe cases of Salmonella enterocolitis. Short-course ceftriaxone therapy is clinically beneficial to these patients. Neither clinical nor microbiological relapse was seen after therapy.

Low frequency of HLA-B*2706 in Taiwanese patients with ankylosing spondylitis

The presence of HLA-B27 in patients affected with ankylosing spondylitis (AS) was well established prior to the advent of DNA typing of various genes within the major histocompatibility complex (MHC) in humans. However, molecular typing of the MHC genes revealed that B27 comprises a motley assortment of alleles, some of which are strongly positively associated with the disease and some of which are negatively associated with the disease. B*2706 was reported to have a negative association with AS in the Thai population and in Chinese Singaporeans. We report here our finding of an absence of B*2706 in 184 Taiwanese AS patients.

Confirmation of a recombinant allele B*5603 and a hypothetical reciprocal hybrid

From its DNA sequence, B*5603 is thought to be a product of gene conversion. We present here serological evidence of such an event and further speculate on a possible reciprocal hybrid yet to be identified. In addition, we report the allelic frequency of B*5603 in the Taiwanese population and its association with A*1101, Cw*01 and DRB1*1201.

Effects of selected minerals on leptin secretion in streptozotocin-induced hyperglycemic mice

The effects of lithium, magnesium, vanadate, and zinc on leptinemia and leptin secretion by adipose tissue were investigated in streptozotocin- (STZ) induced hyperglycemic mice. After the administration of studied minerals in drinking water for 4 weeks, fasting serum leptin concentrations were elevated, accompanied by normoglycemia in STZ-injected mice, regardless which mineral was provided (P < 0.05). However, the in vitro administration of lithium, magnesium, and vanadate did not significantly influence the leptin secretion of adipose tissue. A low zinc treatment (0.1 mM) augmented, whereas both a pharmacological treatment of zinc (1 mM) and zinc depletion (1 mM TPEN) attenuated, leptin secretion (P < 0.05). The present study shows that STZ-induced hyperglycemic mice have hypoleptinemia and reduced leptin secretion by adipose tissue. Moreover, these defects can be improved by a moderate zinc administration.

Studies on anthracenes. 3. Synthesis, lipid peroxidation and cytotoxic evaluation of 10-substituted 1,5-dichloro-9(10H)-anthracenone derivatives

The synthesis of a series of 1,5-dichloro-9(10H)-anthracenones bearing O-linked and N-linked substituents in the 10-position are described. Previous studies have shown that 9-acyloxy 1,5-dichloroanthracenes and 9-acyloxy 1,8-dichloroanthracenes displayed a potential cytotoxic effect. These results have encouraged us in further investigation of potential anthracenone derivatives. Therefore, a series of 10-substituted 1,8-dichloro-9(10H)-anthracenone derivatives were synthesized. These compounds were evaluated for their ability to inhibit the growth of human oral epidermoid carcinoma cells (KB cell line), human cervical carcinoma cells of ME 180 (GBM 8401) and Chinese hamster ovary (CHO) cells, respectively. Compounds 3c and 4c of this series compare favorably in the KB cellular assay with mitoxantrone. Compound 4c showed combined inhibitory action against KB, GBM and CHO cell growth, respectively. In addition, redox property of the compounds for the inhibition of lipid peroxidation in model membranes was determined. Compounds 4b and 4d exhibited stronger antioxidant activity than ascorbic acid, (+)-alpha-tocopherol and mitoxantrone, respectively.

Can short-term administration of dexamethasone abrogate radiation-induced acute cytokine gene response in lung and modify subsequent molecular responses?

PURPOSE

To investigate the effects of short-term administration of dexamethasone (DEX) on radiation-induced responses in the mouse lung, focusing on expression of pro-inflammatory cytokine and related genes.

METHODS AND MATERIALS

At indicated times after thoracic irradiation and/or drug treatment, mRNA expression levels of cytokines (mTNF-alpha, mIL-1 alpha, mIL-1 beta, mIL-2, mIL-3, mIL-4, mIL-5, mIL-6, mIFN-gamma) and related genes in the lungs of C3H/HeN mice were measured by RNase protection assay.

RESULTS

Radiation-induced pro-inflammatory cytokine mRNA expression levels in lung peak at 6 h after thoracic irradiation. DEX (5 mg/kg) suppresses both basal cytokine mRNA levels and this early response when given immediately after irradiation. However, by 24 h, in mice treated with DEX alone or DEX plus radiation, there was a strong rebound effect that lasted up to 3 days. Modification of the early radiation-induced response by DEX did not change the second wave of cytokine gene expression in the lung that occurs at 1 to 2 weeks, suggesting that early cytokine gene induction might not determine subsequent molecular events. A single dose of DEX attenuated, but did not completely suppress, increases in cytokine mRNA levels induced by lipopolysaccharide (2.5 mg/kg) treatment, but, unlike with radiation, no significant rebound effect was seen. Five days of dexamethasone treatment in the pneumonitic phase also inhibited pro-inflammatory cytokine gene expression and, again, there was a rebound effect after withdrawal of the drug.

CONCLUSIONS

Our findings suggest that short-term use of dexamethasone can temporarily suppress radiation-induced pro-inflammatory cytokine gene expression, but there may be a rebound after drug withdrawal and the drug does little to change the essence and course of the pneumonitic process.

Risperidone augmentation of specific serotonin reuptake inhibitors in the treatment of refractory obsessive-compulsive disorder: report of two cases

The efficacy of specific serotonin reuptake inhibitors (SSRI) in the treatment of obsessive-compulsive disorder (OCD) has been established, but more than 40% of patients continue to have a poor response to SSRI. Low-dose antipsychotic augmentation of SSRI has contributed to the amelioration of symptoms in the treatment of refractory obsessive-compulsive disorder patients. Due to the risk of side effects from traditional antipsychotics, atypical novel antipsychotic augmentation of SSRI may be a good choice in the treatment of refractory obsessive-compulsive disorder. Herein we report our experience with two OCD patients, one with a poor response to fluoxetine 80 mg per day for 3 months, and the other with poor response to fluoxetine 60 mg per day for 3 months. Both OCD patients also proved to have a poor response to paroxetine 60 mg per day for 6 weeks. Neither patient had received any psychotherapy or behavioral therapy. Both patients showed significant improvement in their obsessive-compulsive symptoms as measured by the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS), after risperidone 1 mg per day was added to their on-going use of paroxetine 60 mg per day. Within 4 weeks of adding risperidone, the two patients' Y-BOCS scores had decreased by 57% and 53%. This result suggests that risperidone augmentation of SSRI may be a good choice and an effective treatment strategy for refractory OCD.

Combined phototherapeutic keratectomy and therapeutic contact lens for recurrent erosions in bullous keratopathy

AIMS

To evaluate the therapeutic effects of excimer laser phototherapeutic keratectomy (PTK) combined with therapeutic contact lens for painful recurrent corneal erosions (RCE) secondary to bullous keratopathy (BK) not suitable for penetrating keratoplasty.

METHODS

Excimer laser PTK was performed prospectively in eight eyes with painful RCE due to BK visually expecting no benefit from penetrating keratoplasty. After mechanical removal of the epithelium, the corneas were ablated with 50 pulses in the central 6.5 mm zone (ablation rate 0.25 microm per pulse) and another 200 pulses for polishing the periphery. After PTK, therapeutic contact lenses were applied for 3 months. The mean follow up period after PTK was 10.9 months (ranging from 6 to 15 months).

RESULTS

All patients experienced relief of their pain symptoms after the epithelium healed. Only one patient complained of occasional stinging pain with intermittent recurrence of small bullae. He refused a second treatment because the pain was much less than that before the surgery and quite tolerable. No infection or other complications were noted.

CONCLUSION

PTK with deeper ablation and adjunctive therapeutic contact lens is an easy to perform and effective treatment with less recurrence rate for patients with BK and poor visual potential.

Bilateral neurotrophic keratopathy complicating Vidian neurectomy

PURPOSE

To present a case of bilateral neurotrophic keratopathy with miosis after bilateral Vidian neurectomy for vasomotor rhinitis.

METHODS

Observational case report.

RESULTS

A 68 year-old man presented with irritation and blurred vision in both eyes 2 weeks after bilateral Vidian neurectomy. Slit-lamp examination revealed a large epithelial defect, typical of neurotrophic keratopathy, in the inferior two-thirds of cornea in both eyes. Corneal sensitivity test with a Cochet-Bonnet anesthesiometer and electrical study of the blink reflex indicated bilateral trigeminal dysfunction. Both pupils were miotic, and tests with hydroxyamphetamine 1% and epinephrine 0.1% showed postganglionic sympathetic nerve damage. The corneal epithelial defects healed after 2 months of treatment with systemic prednisolone, vitamin B(12) and tarsorrhaphy.

CONCLUSION

Neurotrophic keratopathy associated with dry eye syndrome may be a serious complication of Vidian neurectomy.

Upper eyelid mycobacterial infection following Oriental blepharoplasty in a pulmonary tuberculosis patient

Bilateral upper blepharoplasty for the Oriental eyelid was performed in a 20-year-old female on antituberculous therapy for 3 months. The postoperative course was smooth and the patient was back to normal life. But unfortunately, at 3 months after the upper blepharoplasty, a spherical tumescence and red granuloma developed over the right upper eyelid. The granuloma was resected, and on pathological examination the specimen revealed epitheloid granuloma with Langhan's giant cells and a few acid-fast positive bacilli. The clinical events and pathological findings were suggestive of Mycobacterium tuberculosis rather than Mycobacterium chelonei as the possible cause of infection. Thus the patient was advised to continue antituberculous therapy and no antibiotic was prescribed. The eyelid swelling resolved gradually and was completely normal at the end of antituberculous therapy. Though it has been suggested that aesthetic surgery can be performed safely 3 months after antituberculous therapy in a patient with pulmonary tuberculosis, the remote risk of such a complication is always a possibility.

The thermal environment of arboreal pools and its effects on the metabolism of the arboreal, oophagous tadpoles of a Taiwanese tree frog, Chirixalus eiffingeri (Anura: Rhacophoridae)

We have studied seasonal and diurnal fluctuations of water temperature in bamboo stumps and the effect of temperature on the energy metabolism of arboreal, oophagous tadpoles of Chirixalus eiffingeri. We collected tadpoles (Gosner stage 28-29) in February and August from Chitou, Taiwan and acclimated them to 12 and 22 degrees C. Using a closed system, we measured tadpole oxygen consumption (V.O(2)) at 12, 17 and 22 degrees C. The water temperature was lowest in February (11-13 degrees C), increased rapidly during March and April and was highest from May to August (20-24 degrees C). Diel fluctuations in the temperature of the pools of water in bamboo stumps mirrored fluctuations in air temperature. Tadpoles collected in February and August exhibited metabolic compensation in that tadpoles acclimated at 12 degrees C had significantly higher V.O(2) than those acclimated at 22 degrees C. There are at least two possible explanations for the presence of metabolic compensation in C. eiffingeri tadpoles. Firstly, the larval period of C. eiffingeri ranges from 40 to 78 days, a tadpole could experience relatively large fluctuations in body temperature (up to 10 degrees C) during the development. As a result, C. eiffingeri tadpoles most likely evolved metabolic compensation to maintain activity levels under different thermal environments. Secondly, because arboreal pools are small, thermally unstratified, aquatic microhabitats, tadpoles are unable to behaviorally select preferred temperatures. As a result, metabolic compensation allows tadpoles to regulate their physiological functions.

Phenotype II triploid pregnancy and study of the parental origin of the extra set of chromosomes with fluorescence microsatellite analysis: case report

Triploidy can reflect diandry (dispermy or diploid sperm) or digyny(diploid ovum). The former is likely to result in the type I phenotype with a partial mole with an appropriate-for-gestational age fetus rarely surviving beyond 20 weeks and a large, cystic placenta. The latter, however, is characterized by a type II phenotype with severe intrauterine growth retardation (IUGR) with longer in utero survival and a small, non-molar placenta. We report on a 22-year-old woman, gravida 2, para1, in the 31st week of gestation who was referred to our prenatal clinic for evaluation of severe IUGR and oligohydramnios. Late cytogenetic karyotyping from cordocentesis revealed a triploidy of 69, XXX. In the 33rd week of gestation, the mother went through spontaneous labor delivering an IUGR 1180 gm fetus and a small, non-molar placenta. The fetus died immediately and was sent for autopsy. In addition to cleft lip and palate, the infant had pulmonary lobation abnormalities. Fluorescence microsatellite analysis of fetal and parental samples confirmed that the extra set of chromosomes present in the proband was a result of a maternal meiosis I nondisjunction error. This may help study of genomic imprinting on human development.

Brachial plexus injury following coronary artery bypass surgery: a case report

Postoperative brachial plexus injury, often manifesting as a variety of upper extremity neuropathies, is a recognized and not uncommon complication following cardiac surgery that requires a median sternotomy. In general, the vast majority of its neurological symptoms are transient and need no treatment. Nevertheless, in very rare cases, the peripheral neuropathies will persist and cause disability. We treated a 67-year-old male patient complicated by permanent paresthesia and paralysis of the left upper extremity after an eventful coronary artery bypass surgery. The nerve conduction measurements and electromyography all revealed a C5 to T1 lesion. After carefully reviewing the surgical course and referring to the published literature, we tentatively concluded that compression or overstretching produced by wide and prolonged sternal separation of the brachial plexus was the most likely etiology. Asymmetrical traction of the sternal halves during internal mammary artery harvesting might also have contributed to this nerve injury. We surmised, therefore, that brachial plexus injury could be minimized by an exact median sternotomy, a lower position and the smallest possible opening for the sternal retractor, and the avoidance of constant and asymmetrical traction on the sternal halves.

Surgical outcome after curative resection of rectal leiomyosarcoma

PURPOSE

The aim of this study is to present the prognosis and possible associated prognostic factors after curative resection of rectal leiomyosarcoma.

METHODS

From 1979 to 1996 our hospital saw 40 patients with rectal leiomyosarcoma, including 19 females, who did not have metastasis initially and received curative resection and regular postoperative follow-up.

RESULTS

The mean age of the 40 patients was 58.7 years. Anal bleeding and perianal pain were the two most common symptoms at initial diagnosis. Twenty-nine patients received a radical surgical resection, such as abdominoperineal resection or low anterior resection; the other 11 patients received a wide local excision, such as transrectal excision or Kraske's operation. Sixteen tumors were classified as high-grade leiomyosarcoma, and 23 as low grade. Nineteen patients (48 percent) developed recurrence or metastasis postoperatively (median follow-up, 35 months). The overall and disease-free (1-year, 3-year, and 5-year) survival rates were 97, 90, and 75 percent and 90, 59, and 46 percent, respectively. In univariate analysis, younger group (<50 years, n = 9, P = 0.033) and high-grade leiomyosarcoma (P = 0.043) showed poorer prognosis in the disease-free survival curve. In the multivariate Cox model, gender, tumor size, tumor location, and operation type did not significantly affect disease-free survival, whereas histologic grade (P = 0.037) and age divided by a level of 50 years (P = 0.009) were shown to be independent factors. There was a strong trend toward higher local recurrence rate for the wide local excision group than for the radical resection group (55 vs. 24 percent, P = 0.067) despite the wide local excision group being composed of smaller tumors (5.1 vs. 7.5 cm, P = 0.069). There was no difference in the incidence of distant metastasis between the two groups with different operation types. The metastasis rates of the wide local excision and radical resection groups were 27 and 38 percent, respectively.

CONCLUSION

A younger age (<50 years) and a high histologic grade of tumor were the two most significant poor prognostic factors for rectal leiomyosarcoma. Radical resection may be superior to wide local excision in the prevention of local recurrence but not distant metastasis.

Zinc-induced hyperleptinemia relates to the amelioration of sucrose-induced obesity with zinc repletion

OBJECTIVE

Dietary zinc repletion can ameliorate sucrose-induced obesity. A positive correlation between zinc and leptin has been recently noted, and both are known as important mediators in appetite control. In this study, we examined whether the reported amelioration of sucrose-induced obesity by zinc repletion was consequent on the changes in circulating leptin levels.

RESEARCH METHODS AND PROCEDURES

Mice with obesity that was induced by giving a 32% sucrose solution in addition to a semipurified diet were divided into two groups based on whether they had 20 mg/liter zinc supplementation in their drinking water.

RESULTS

As expected, the mice with sucrose-induced obesity had hyperglycemia, hyperinsulinemia, hypertriglyceridemia, hyperleptinemia, and hypozincemia when compared with the mice given the diet alone. Body weight gain, body fat content, and food and sucrose intake tended to decrease but not with statistical significance in sucrose-fed obese mice with zinc supplementation. Nevertheless, some serum variables (glucose, insulin, triglycerides, and zinc) in sucrose-fed obese mice with zinc treatment were approximate to those values of the mice given the diet alone. Moreover, sucrose-fed obese mice with zinc supplementation had the highest serum values of leptin.

DISCUSSION

This study indicates that the amelioration of sucrose-induced obesity by zinc repletion may be partly attributable to the hyperleptinemia induced by the mineral.

Concomitant neuroleptic malignant syndrome and lithium intoxication in a patient with bipolar I disorder: case report

The purpose of this report is to remind clinicians of the risk of the simultaneous occurrence of neuroleptic malignant syndrome (NMS) and lithium intoxication. A 39-year-old female with bipolar I disorder was admitted to our psychiatric ward due to relapse of a manic episode and a suicide attempt in which she had ingested 20 to 30 tablets of lithium (300 mg/tablet) 12 hours before admission. Except for intramuscular injection of 5 mg of haloperidol 30 minutes after admission, the patient received no antipsychotic drugs during her hospitalization. Six hours after admission, she began to show symptoms of NMS. Lithium intoxication was also found. Within a week, her condition had stabilized with no neurological complications or cognitive deficits noted during the following 4 months. Discussed in this case report are the risk factors of NMS found in this patient, drug interactions of lithium and antipsychotic agents as related to NMS, and problems in clinical management.

Effect of zinc on cellular levels of calmodulin and cyclic adenosine monophosphate in the adipocyte

A perturbation of zinc metabolism has been noted in subjects with obesity. Zinc may also participate in the intracellular signal cascade by affecting cellular calcium influx and a change in the calcium-calmodulin (CaM)-cyclic adenosine monophosphate (cAMP) pathway. The possible effects of zinc on cellular concentrations of CaM, a major cytosolic calcium-binding protein, in the adipocytes derived from obese (ob/ob) mice and their lean counterparts were studied. Adipocytes derived from both phenotypes of mice were treated either with 0.2 mM of zinc sulfate or without any additive for 1 h of incubation; the cellular levels of CaM and cAMP were then determined. The results showed that the obese mice had lower CaM and cAMP levels in their adipocytes compared to the lean mice. Zinc treatment reduced CaM and increased cAMP levels in all mice, although this effect was more pronounced in the lean mice. This study indicated that there was an inverse interaction between CaM and cAMP in their cellular levels in the mouse adipocytes and that might be affected by exogenous zinc addition.

Zinc may be a mediator of leptin production in humans

Obese individuals have hyperleptinemia and hypozincemia. Moreover, leptin and zinc have circadian changes in circulating concentrations. We investigated their possible interaction and examined whether a difference existed between obese men and their lean controls. The results indicated the pattern of circadian change in plasma zinc and leptin did not markedly differ between the obese subjects and the lean controls. However, the obese had higher leptin and lower zinc plasma values at each sampling time than did the lean controls. Because an inverse correlation was found in plasma values between zinc and leptin (r=-0.51, p=0.012), we further determined the role zinc might play in leptin production by human subcutaneous adipose tissue from female donors. The in vitro study showed that zinc treatment (0.2 mmol/L) significantly increased leptin production (142%), however, this increment did not surpass that by insulin (10 nmol/L). The data of this study suggest an interactive connection between zinc and leptin.

Papillary cystic neoplasm of the pancreas in children: report of three cases

Papillary cystic neoplasm of the pancreas is very rare in children. There were only 35 pediatric cases reported in the literature. We herein three children who had papillary cystic neoplasm of pancreas. They were female teenagers, and were pathologically diagnosed. The major presenting symptoms were abdominal pain and abdominal mass. Serum tumor markers of these patients showed normal results. A CT scan of these patients showed that this tumor was of pancreatic origin. These 3 tumors were localized to head, body, and tail, respectively. The mean maximal diameter of these tumors was 11.3 +/- 3 cm. Sonography and CT examination showed that the tumor was a heterogeneous mass with solid and cystic components. Angiography of this tumor showed a hypervascular mass with blood supply mainly from pancreatic branch of splenic artery. They all underwent tumor resection. All tumors contained some degree of internal hemorrhage or cystic degeneration and all were well encapsulated. Histologically, tumor cells generally showed solid and pseudopapillary growth around the fibrovascular stalks. No metastasis, mortality or recurrence was noted during follow-ups. In conclusion, CT scan helps to make a prospective diagnosis of papillary cystic neoplasm of pancreas. Our study confirmed that a papillary neoplasm of the pancreas is a low-grade malignant tumor. Surgical resection of the tumor is the mainstay of effective management.

Zinc effects on hyperglycemia and hypoleptinemia in streptozotocin-induced diabetic mice

Zinc has an antihyperglycemic effect. Zinc can also influence the production of leptin, a satiety factor that reduces appetite and blood sugar level. In this study, we investigated the effect of zinc supplementation on food intake and circulating leptin and glucose concentrations in streptozotocin-induced diabetic mice. Male diabetic mice received zinc supplementation (20 ppm) from drinking water for two weeks. The results showed that zinc treatment did not affect body weight gain, body fat content or food intake in these diabetic mice. However, zinc supplementation markedly ameliorated the hyperglycemia of diabetic mice. After zinc treatment, serum leptin concentrations tended to increase in the diabetic mice. This study suggests that zinc is a mediator of leptin production.

Zinc and nitric oxide synthase inhibitor L-NAME attenuate NPY-induced feeding in mice

The influences of zinc (Zn) and the nitric oxide synthase (NOS) inhibitor L-NAME on peripheral neuropeptide Y (NPY)-induced feeding in mice were investigated. Male mice received NPY (200 ng/d/mouse subcutaneously) and were separated into four groups based on cotreatments (with or without Zn [0.1 mg/mL]) and with or without L-NAME [0.2 mg/mL]) administered in drinking water for 10 d. A control group that received saline injection was also studied. The results showed that NPY, with or without any studied chemicals, did not affect body weight gain or body fat content. However, the mice that were administered NPY alone had increased energy intakes, higher serum triglyceride and free fatty acid, and lower serum glucose than saline-injected controls. NPY-treated mice that were given Zn and L-NAME cotreatments had compatible results of determined variables in comparison with control mice. This study showed that Zn and L-NAME attenuated NPY-mediated feeding and selected serum variables in mice. However, the mechanisms of the interactions among NPY, Zn and NOS, and their effects on appetite regulation, remain to be elucidated.

Characterization of novel 10-substituted 1,8-dihydroxy-9(10H)-anthracenone derivatives by mass spectrometry

Anthralin and its derivatives containing a variety of simple or functionalized aliphatic and aromatic substituents are of special interest in research on psoriasis. In this connection, 10-arylthio-1,8-dihydroxy-9(10H)-anthracenones were synthesized and examined by means of mass spectrometry. In general, the molecules in question fragmented upon electron impact into ions at m/z 225 (C-S bond cleavage and charge retention at the anthralin component) and into ions of unknown structure at m/z 226, requiring H-migration from the S-bound substituent R into the anthralin moiety. Since mass spectrometry methods furnished us elegant, matchless means of tracing the amounts of material in the analysis, especially in the case of physiologically active compounds, we decided to use mass spectrometry procedures for unequivocal identification and purity determination of 10-arylthio-anthralins.

Rapid induction of cytokine gene expression in the lung after single and fractionated doses of radiation

PURPOSE

To investigate cytokine gene expression in the lung after single and fractionated doses of radiation, and to investigate the effect of steroids and the genetic background.

MATERIALS AND METHODS

Expression of cytokine genes (mTNF-alpha, mIL-1alpha, mIL-1beta, mIL-2, mIL-3, mIL-4, mIL-5, mIL-6, mIFN-gamma) in the lungs of C3H/HeJ and C57BL/6J mice was measured by RNase protection assay at different times after various doses of radiation. The effects of dexamethasone and fractionated radiation treatment on gene expression were also studied.

RESULTS

IL-1beta was the major cytokine induced in the lungs of C3H/HeJ mice within the first day after thoracic irradiation. Radiation doses as low as 1 Gy were effective. Responses to 20 Gy irradiation peaked within 4-8h and subsided by 24 h. With the exception of IL-1alpha and TNF-alpha, the other cytokines that were investigated had undetectable pre-treatment mRNA levels and were not radiation inducible. Similar responses were seen in C57BL/6J mice, although TNF-alpha was induced and there were some quantitative differences. Pre-treatment of C3H/HeJ mice with dexamethasone reduced basal and induced IL-1 levels, but complete inhibition was not achieved. Dexamethasone was also effective if given immediately after irradiation. Fractionated daily doses of radiation (4 Gy/day) helped to maintain cytokine gene expression for a longer period.

CONCLUSIONS

Inflammatory genes are rapidly induced in the lung by irradiation. This response cannot be readily abolished by steroid pre-treatment. Fractionated treatment schedules help to perpetuate the response.

Zinc coadministration attenuates melatonin's effect on nitric oxide production in mice

Both melatonin (MEL) and zinc (Zn) are considered beneficial for anti-immunosenescence. MEL's effects on immune functions are partly attributed to an interaction with Zn. However, the augmentation of or interference with MEL's effects by coadministration of Zn remains unclear. In this study, adult older mice received either MEL (10 microg/mL), Zn (22 microg/mL), MEL+Zn, or null supplementation from drinking water for 3 mo. The results showed that treated mice, irrespective of the type of added chemicals, had higher body-weight gain and body-fat content than control mice. MEL- and Zn-treated mice also had increased serum free fatty acid levels. In addition, the MEL group had decreased serum NOx (nitrite+nitrate) values. Serum tumor necrosis factor-alpha levels were increased, although nonsignificantly, in mice that received either MEL or Zn supplementation. However, the differences described were not retained in the mice that received MEL+Zn treatment. We conclude that a high-dose Zn coadministration might exert negative influences on MEL's regulatory effects, at least on nitric oxide production.

Olestra formulation and the gastrointestinal tract

Olestra is a mixture of compounds comprising sucrose esterified with 6-8 long-chain fatty acids. It is not hydrolyzed by pancreatic lipase and as a result is not absorbed from the small intestine. Olestra in general has physical properties similar to those of a triacylglycerol with the same fatty acid composition. Foods made with olestra are virtually identical in taste and texture to those made with typical triacylglycerols. Olestra consumption does not generate hydrolytic products in the small intestine and, therefore, does not generate some of the signals that alter motility in the gastrointestinal tract. A reduction in gastroesophageal reflux with olestra, in contrast to triacylglycerols, is consistent with a lack of effect on stomach emptying. Unlike triacylglycerols that are absorbed in the proximal small intestine, olestra is distributed throughout the small intestine during transit and passes into the colon. In the colon, olestra's effects depend on its physical properties. Liquid nondigestible lipids result in separation of oil from the fecal matrix. Olestra formulations made with specific fatty acid compositions, particularly those containing a solid sucrose polyester component including behenic acid, possess appropriate rheology to hinder separation of oil from the rest of the fecal matrix, thereby reducing gastrointestinal symptoms.

Heterogeneity of HLA-DR2 haplotypes in Caucasoid Americans, African Americans, Chinese Americans, Native Americans and Xiamen Chinese

HLA-DR, -DQ specificities were determined by PCR amplification with SSOP in 4560 individuals: Caucasoid Americans (CA), African Americans (AA), Chinese Americans (ChA), Native Americans (NA) and Xiamen Chinese (XC). DR2 subtypes were compared amongst the five ethnic populations. The DRB1*1501-DRB5*0101 haplotype was found to be the most frequent in all populations except African Americans, in which DRB1*1503-DRB5*0101 was the predominant haplotype, accounting for 65% of DR2 subtypes. In contrast to Caucasoid Americans, the DRB1*1602 is strongly associated with the DRB5*0101 allele in Chinese populations. The presence of DRB5*0203 and DRB1*1602-DRB5*0101 haplotypes in Chinese populations, especially in Xiamen Chinese, suggests that various DR2 haplotypes may be generated via multiple gene conversion events together with point mutations and reciprocal recombination. The strong DR and DQ associations are found in DRB1*1501/DQB1*0602 (66.22%) for CA, DRB1*1503/DQB1*0602 (56.58%) for AA, DRB1*1501/DQB1*0602 (30.20%) and DRB1*1602/DQB1*0502 (15.76%) for ChA, DRB1* 1501/DQB1*0602 (41.55%) and DRB1*1602/DQB1*0301 (40.25%) for NA, and DRB1*1501/DQB1*0602 (30.26%) and DRB1*1602/DQB1*0502 (25.81%) for XC.

Mitral valve replacement in the presence of massive posterior annular calcification

Replacement of the mitral valve in the presence of extensive calcification of the posterior annulus is a technical challenge. The heavily calcified annulus often results in difficulties of seating the prosthesis and later periprosthetic leakage. A radical calcium debridement may leave a friable and thin annulus that contributes to the risks of prosthesis dehiscence and ventricular perforation. To avoid technical difficulties and associated catastrophic complications, we devised a new technique of mitral valve replacement that allows a surgeon to implant a prosthesis securely. This technique involves inserting a larger single tilting disc mechanical valve (Medtronic Hall disc) with intra-atrial anchorage over the posterior sector of the calcified annulus, orienting the working (major) orifice of the mechanical valve anteriorly, and thereby tilting the lesser occluder segment of the disc upward into the atrium and away from the calcification in diastole. By utilizing this method, we have successfully performed mitral valve replacement in two patients who exhibited massive calcification of the posterior mitral annulus. Postoperative transeosophageal echocardiography showed excellent hemodynamic performance of the implanted valves. We therefore recommend this simple, safe, and time-saving procedure as a feasible method to deal with this surgical dilemma.