Multiplex Protein Imaging through PACIFIC: Photoactive Immunofluorescence with Iterative Cleavage

Multiplex protein imaging technologies enable deep phenotyping and provide rich spatial information about biological samples. Existing methods have shown great success but also harbored trade-offs between various pros and cons, underscoring the persisting necessity to expand the imaging toolkits. Here we present PACIFIC: photoactive immunofluorescence with iterative cleavage, a new modality of multiplex protein imaging methods. PACIFIC achieves iterative multiplexing by implementing photocleavable fluorophores for antibody labeling with one-step spin-column purification. PACIFIC requires no specialized instrument, no DNA encoding, or chemical treatments. We demonstrate that PACIFIC can resolve cellular heterogeneity in both formalin-fixed paraffin-embedded (FFPE) samples and fixed cells. To further highlight how PACIFIC assists discovery, we integrate PACIFIC with live-cell tracking and identify phosphor-p70S6K as a critical driver that governs U87 cell mobility. Considering the cost, flexibility, and compatibility, we foresee that PACIFIC can confer deep phenotyping capabilities to anyone with access to traditional immunofluorescence platforms.

The incidence and characteristics of 3-month mortality after intraoperative cardiac arrest in adults

BACKGROUND

There is little information about clinical outcomes after intraoperative cardiac arrest (IOCA). We determined the incidence and characteristics of 3-month mortality after IOCA.

METHODS

The electronic medical records of 238,648 adult surgical patients from January 2005 to December 2014 were reviewed retrospectively. Characteristics of IOCA were documented using the Utstein reporting template.

RESULTS

IOCA occurred in 50 patients (21/100,000 surgeries). Nineteen patients died in the operating room, and further 12 patients died within 3 months post-arrest (total mortality: 62%). Three survivors at 3 months post-arrest had unfavourable neurological outcome. Finally, 34 patients showed unfavourable clinical outcomes at 3 months post-arrest. The incidences of non-cardiac surgery, emergency, pre-operative intubation state, non-shockable initial cardiac rhythm, hypovolaemic shock, pre-operative complications-induced cardiac arrest, non-anaesthetic cause of cardiac arrest, intra- and post-arrest transfusion, and continuous infusion of inotrope or vasopressor in intensive care unit (ICU) were significantly higher in non-survivors at 3 months post-arrest. Total epinephrine dose administrated during arrest was higher, and the duration of cardiac compressions was longer in non-survivors at 3 months post-arrest.

CONCLUSIONS

In this study, the incidence of IOCA was 21/100,000 surgeries and the 3-month mortality rate after IOCA was 62%. Several factors including surgical emergency, non-shockable initial cardiac rhythm, pre-operative complications, surgical complications, long duration of cardiac compressions, high total epinephrine dose, transfusion, and continuous infusion of inotropes or vasopressors in ICU seemed to be risk factors for 3-month mortality after IOCA. These risk factors should be considered in the light of relatively small sample size of this study.

Evaluation of ABX Pentra DX 120 and Sysmex XE-2100 in umbilical cord blood

INTRODUCTION

Cord blood (CB) is an important source of hematopoietic stem cells and reflects the hematologic status of neonates. ABX Pentra DX 120 (Horiba Medical, Montpellier, France) and Sysmex XE-2100 (Sysmex, Kobe, Japan) were compared in 200 CB specimens.

METHODS

Complete blood count parameters including white blood cell (WBC) differential counts were compared between the two analyzers. Double differential matrix (DDX) by ABX Pentra DX 120 and hematopoietic progenitor cell (HPC) by Sysmex XE-2100 were compared with CD34(+) cells by flow cytometry.

RESULTS

Most of the parameters showed acceptable correlation between the two analyzers. Although WBC differential of both analyzers showed acceptable correlation with manual counts, mononuclear cells (MNC) by ABX Pentra DX 120 better correlated with manual count than MNC by Sysmex XE-2100. NRBC by Sysmex XE-2100 better correlated with manual count than NRBC by ABX Pentra DX 120. ABX Pentra DX 120 showed better flagging performances. DDX better correlated with CD34(+) cells than HPC.

CONCLUSION

Although the results from both analyzers are mostly interchangeable and reliable in CB specimens, flagging performance of ABX Pentra DX 120 seems to be superior to that of Sysmex XE-2100. DDX by ABX Pentra DX 120 would be valuable to evaluate the quality of CB for further therapeutic utilization.

Establishment of reference interval for immature platelet fraction

INTRODUCTION

Immature platelet fraction (IPF) is a parameter for reticulated platelets. A high percentage IPF (%-IPF) is indicative of consumptive or recovering thrombocytopenic disorders in contrast to a low %-IPF seen in aplastic states. Absolute IPF (A-IPF) specifically reflects the number of immature platelets in circulation. This study aimed to establish reliable reference intervals for %-IPF and A-IPF.

METHODS

Except outliers, platelet counts and IPF were determined in 2152 healthy individuals (1252 men and 900 women) and 133 umbilical cord blood from healthy full-term neonates using XE-2100 hematology analyzer (Sysmex, Kobe, Japan). The reference intervals for %-IPF and A-IPF were defined using nonparametrical percentile methods according to the Clinical and Laboratory Standard Institute (CLSI) guideline.

RESULTS

Platelets,%-IPF, and A-IPF all showed nonparametrical distributions. In total individuals, the reference intervals for %-IPF and A-IPF were 0.5-3.3% (0.5-3.1% in men; 0.5-3.4% in women) and 1.25-7.02 × 10(9) /L (1.30-6.80 × 10(9) /L in men; 1.21-7.15 × 10(9) /L in women), respectively. The reference intervals for %-IPF and A-IPF in umbilical cord blood were 0.7-3.8% and 1.93-9.7 × 10(9) /L, respectively.

CONCLUSIONS

This study provides the reference interval for IPF, including %-IPF and A-IPF, according to the CLSI guideline. These results could be used as fundamental data for clinical use as well as future researches.

Fecal carriage of extended-spectrum β-lactamase-producing Enterobacteriaceae in Korean community and hospital settings

PURPOSE

The assessment and early recognition of risk factors for infections due to extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) are important for infection control and proper treatment. The aim of the present study was to investigate the prevalence of fecal carriage of ESBL-E in healthy individuals and hospitalized high-risk patients in Korea and to compare the characteristics of ESBL-E in these two groups.

METHODS

A total of 384 samples from 290 healthy individuals and 94 high-risk patients were collected. The screening of ESBL-E was performed using a commercial chromogenic medium. Bacterial identification and antibiotic susceptibility testing were performed using the Vitek 2 system.

RESULTS

The prevalence of ESBL-E carriage was 20.3 % in healthy individuals and 42.5 % in high-risk patients. Escherichia coli comprised a large majority (96.6 %) of the isolates from healthy individuals, but Klebsiella pneumoniae was more commonly detected (45.0 %) in high-risk patients than in healthy individuals. K. pneumoniae isolates exhibited significantly higher resistance to ceftazidime, ampicillin, and carbapenem, and E. coli exhibited higher resistance to cefotaxime. E. coli from high-risk patients exhibited significantly higher resistance to levofloxacin and cefepime than that from healthy individuals.

CONCLUSIONS

We demonstrated the high prevalence of ESBL-E carriage in Korea and clarified the characteristics of ESBL-E carriage in healthy individuals and high-risk patients. The distribution and antibiotic susceptibility of colonizing ESBL-E were different between the group of healthy individuals and the high-risk patients. Active surveillance of ESBL-E carriage is suggested for infection control, and the use of chromogenic agar appears to be an efficient method.

Detection of tuberculosis using artus M. tuberculosis PCR Kit and COBAS AMPLICOR Mycobacterium tuberculosis Test

SETTING

Nucleic acid amplification tests can detect Mycobacterium tuberculosis complex rapidly and reliably.

OBJECTIVE

To compare the diagnostic performance of the artus M. tuberculosis PCR Kit and COBAS AMPLICOR Mycobacterium tuberculosis Test. In the artus assay, an appropriate cycle threshold (Ct) value was determined for positivity.

DESIGN

A total of 238 clinical respiratory specimens were analysed using both the artus and COBAS AMPLICOR assays. In 221 specimens, these results were further compared with culture results.

RESULTS

The overall agreement between artus and COBAS AMPLICOR was 96.2% (229/238). Among the nine (3.8%) discrepant specimens, three (1.3%) were artus-positive and COBAS AMPLICOR-negative, while the other six (2.5%) were artus-negative and COBAS AMPLICOR-positive. Using culture as a standard, the sensitivity and specificity of the artus assay were 97.8% and 85.1%, and those of COBAS AMPLICOR assay were 100% and 86.2%, respectively. The difference was not statistically significant. In the artus assay, the minimum Ct value for the positivity determination was 38.

CONCLUSION

The artus and COBAS AMPLICOR assays showed comparable diagnostic performance and can be confidently used for detection of M. tuberculosis complex. In the artus assay, a Ct value of 38 could be suggested as an appropriate cut-off value.

Isothermal target and probe amplification for Mycobacterium tuberculosis identification from broth cultures

SETTING

Various methods are used to identify Mycobacterium tuberculosis complex (MTC) from broth cultures. The isothermal target and probe amplification (iTPA) method has recently been introduced as a simple and cost-effective molecular assay.

OBJECTIVE

To evaluate the diagnostic performance of the iTPA method.

DESIGN

A total of 175 specimens from the Mycobacteria Growth Indicator Tube (MGIT) 960 broth culture system were evaluated. The immunochromatographic test (ICT) and real-time quantitative PCR (RQ-PCR) were compared with the iTPA method.

RESULTS

MTC was identified in 71/131 MGIT-positive specimens, including 60 ICT-positive and 11 ICT- negative/PCR-positive specimens. The sensitivity and specificity of the ICT assay were respectively 84.5% (95%CI 74.0-92.0) and 100% (95%CI 94.0-100). These 71 specimens were all MTC-positive with the iTPA method also. Sixty non-tuberculous mycobacteria specimens and 44 MGIT-negative specimens were all MTC-negative with the iTPA method.

CONCLUSION

Our data show that the diagnostic performance of the iTPA method is comparable to that of RQ-PCR. The iTPA method could be a reliable and cost-effective option for the identification of MTC from broth culture.

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.

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.

Protein 4.1 deficiency and deletion of chromosome 20q are associated with acquired elliptocytosis in myelodysplastic syndrome

We report a case of myelodysplastic syndrome (MDS), associated with prominent elliptocytosis. A 66-year-old male presented with peripheral pancytopenia, and was diagnosed with MDS [refractory anaemia (RA)]. Apart from marked elliptocytosis, dyshaematopoietic features were not evident in his peripheral blood or hypercellular bone marrow. After 18 months, he had progressed to RA with excess blasts in transformation. Analysis of red blood cell membrane proteins by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) showed a reduced quantity of protein 4.1 (30% of control). Deletion of chromosome 20q was identified by conventional cytogenetic analysis and fluorescence in situ hybridization. Marked elliptocytosis, persistent for more than 17 months, decreased strikingly after chemotherapy with idarubicin and Ara-C. These findings suggest that acquired elliptocytosis occurred as an unusual morphological feature of MDS, associated with abnormalities of protein 4.1 and chromosome 20q.

Change of complement system predicts the outcome of patients with severe thermal injury

To establish the clinical relevance of the changes in the complement system in patients with thermal injury, we studied 20 patients who had third-degree burns on more than 60% of total body surface area. Their levels of the C3, C4, soluble C5b-9, and functional hemolytic activities of total (CH50) and alternative (AH50) complement pathways were sequentially measured for 2 weeks after thermal injury. All patients showed low C3 levels initially but increased C3 levels in the following days. The increasing trend of C3 levels was prominent in survivors but transient and diminished in nonsurvivors. The change of levels of C3, CH50, and AH50 was closely associated with one another, and their chronological trends related to the survival of patients (P =.0060,.0064 and.0066, respectively). The recovery of C3, AH50, and CH50 to normal or supranormal level during the early treatment period relates to the survival of patients with thermal injury. The failure of recovery of the complement system indicates a poor prognosis for patients and the monitoring of complement system might be beneficial in the care of patients with thermal injury.

Lymphoid preponderance and the absence of basophilia and splenomegaly are frequent in m-bcr-positive chronic myelogenous leukemia

Chronic myelogenous leukemia (CML) with a minor bcr-abl transcript is a rare entity. We describe a 66-year-old female who was diagnosed with CML in the chronic phase. Molecular analysis of her Philadelphia chromosome using the reverse transcriptase polymerase chain reaction and subsequent sequencing revealed a minor bcr-abl transcript. Monocytosis resembling chronic myelomonocytic leukemia was observed without splenomegaly and basophilia. Her clinical course was indolent and maintained the chronic phase of CML for nearly 3 years under hydroxyurea treatment. A review of the 23 cases of m-bcr CML including this case showed the presence of monocytosis and the absence of basophilia and splenomegaly in 55.0%, 55.0%, and 70.0% of patients, respectively. The absence of basophilia was a significant finding in patients without monocytosis ( P=0.01). Although the hematological features or clinical outcomes were variable in m-bcr CML cases, all three cases at the onset of the blastic phase showed lymphoid crisis, implying an increased lymphoid leukemogenicity of minor bcr-abl transcripts.

HLA-B*44 allele frequencies and haplotypic associations in Koreans

We have investigated the frequencies of HLA-B*44 alleles and their haplotypic associations with HLA-A, -C, and -DRB1 loci in 450 healthy unrelated Koreans, including 213 parents from 107 families. All 79 samples (17.6%) typed as B44 by serology were analyzed for B*44 alleles using polymerase chain reaction (PCR) single-strand conformation polymorphism (SSCP) method. A total of three different B*44 alleles were detected: B*44031 (allele frequency 4.7%), B*44032 (3.1%), and B*4402 (1.3%). Three characteristic haplotypes revealing strong linkage disequilibrium were A*3303-Cw*1403-B*44031-DRB1*1302 (3.6%), A*3303-Cw*07-B*44032-DRB1*0701 (2.8%), and A*3201-Cw*05-B*4402-DRB1*0405 (0.4%). In addition, a strong association was observed for B*4402 with A*0301. The B*4403-bearing haplotypes of Koreans appear to be relatively common in Asian populations, whereas the B*4402-bearing haplotypes share some similarity to those of Caucasians. HLA-B44 alleles demonstrate a limited allelic diversity and comprise distinctive extended haplotypes in the Korean population. It is suggested that the frequencies of B44 subtype mismatches among ABDRB1-matched unrelated donor-recipient pairs would be low in this population.

Immunophenotypic and cytogenetic changes in acute leukaemia at relapse

To gain more insight into the immunophenotypic and cytogenetic changes in acute leukaemia at relapse, 99 Korean patients treated at a single institution were studied: acute myelogenous leukaemia (AML, n=46), acute lymphoblastic leukaemia (ALL, n=44) and biphenotypic and mixed leukaemia (n=9). Immunophenotypic changes at relapse were observed in 51 of 99 patients (51.5%) with almost even distribution in AML and ALL. Overall expression of aberrant markers on leukaemic cells was more frequent at relapse than at initial diagnosis (P < 0.05), and this finding was most prominent in B lineage ALL (41.4% versus 10.3%, P=0.007). Gain of aberrant CD13 or CD33 at relapse of B lineage ALL was most frequently observed. Cytogenetic changes at relapse were observed in 28 of 46 patients (60.8%). The initially abnormal karyotypes were more frequently associated with clonal changes at relapse compared to initially normal karyotypes (78.3% versus 43.5%, P=0.016). Cytogenetic changes were more frequent in B lineage ALL than in AML (90% versus 47.8%, P=0.05). In ALL, patients showing cytogenetic changes at relapse were significantly younger than those showing no changes (mean age of 15.0 versus 38.8, P=0.002), whereas in AML there was no significant difference between the two groups. In conclusion, the gain of aberrant markers and cytogenetic changes at relapse, which are suggestive of clonal instability, are more prevalent in B lineage ALL compared to AML, and lymphoid leukaemic cells of younger patients are more susceptible to clonal changes at relapse.

Abnormalities of erythrocyte membrane proteins in Korean patients with hereditary spherocytosis

Hereditary spherocytosis (HS) is a common inherited erythrocyte membrane disorder characterized by chronic hemolytic anemia. Clinical manifestations and biochemical abnormalities of HS are heterogeneous. In this study, we investigated erythrocyte membrane protein defects in 27 Korean HS cases. Utilizing both the Fairbanks system and the Laemmli system, sodium dodecyl sulfate polyacrylamide gel electrophoresis of erythrocyte membrane proteins was performed. Proteins were stained with Coomassie brilliant blue and gels were scanned using a densitometer. We detected spectrin deficiency in 7.4% of cases (2/27), ankyrin deficiency in 29.6% (8/27), combined spectrin and ankyrin deficiency in 3.7% (1/27), band 3 deficiency in 11.1% (3/27) and protein 4.2 deficiency in 14.8% (4/27). Membrane protein deficiencies were not observed in nine cases (33.3%, 9/27). Members of two of seven families tested showed the same protein defects as the proband. Ankyrin deficiency alone and combined with spectrin deficiency accounted for 33.3% of cases (9/27), and they were the most common biochemical defects in Korean HS cases. Protein 4.2 deficiency caused HS more frequently in Koreans than in Caucasians.

A successful delivery of a baby from a D--/D-- mother with strong anti- Hr0

We describe the first reported case in Korea of a woman with a D--/ D-- phenotype, a high-titer anti-Hr0, and the successful delivery of her newborn. The mother had a history of spontaneous abortion and artificial termination. In her third pregnancy, a live infant was delivered, but died of severe hemolytic disease of the newborn due to anti- Hr0 in spite of intensive medical intervention. In her fourth pregnancy, at 22 weeks gestation, the titer of anti- Hr0 was 1024, fetal cells were direct antiglobulin test positive and the blood type was group O, D+ (CDe). We performed plasma exchanges in the mother; however, the titer of antibody rebounded to its initial level after the third plasma exchange. At 26 weeks gestation, cord blood Hb decreased to 7.1 g/dL and three intrauterine transfusions were performed using the mother's washed red blood cells (RBCs). At 34 weeks gestation, a live baby was delivered by cesarean section. The infant was hydropic with hyperbilirubinemia and severe anemia. However, after two exchange transfusions using the washed RBCs of the mother's sister, who was also D--/D--, laboratory and clinical findings returned to normal.

Four cases of therapy-related leukemia

Combination chemotherapy and radiation therapy have contributed to the successful treatment of various cancer patients. But the development of second malignancies is an inevitable complication of long-term cytotoxic treatment. The most serious and frequent of such complications is acute myelogenous leukemia (AML). Therapy-related leukemia is generally fatal. Since the number of patients exposed to chemotherapy is increasing each year, the clinical significance of this entity cannot be underestimated. There have been many investigations of therapy-related leukemia, but in Korea published reports are rare. We describe four such cases, involving one older female with lung cancer and three children with acute lymphoblastic leukemia (ALL) and malignant lymphoma. Alkylating agents were used for chemotherapy, and in one case, topoisomerase II inhibitor. Irrespective of the causative agents, the latency periods were relatively short, and despite induction chemotherapy in two, all survived for only a few months. During the follow-up of patients treated for primary malignancies, the possibility of therapy-related leukemia should always be borne in mind.

Comparison of classic intrafascial supracervical hysterectomy with total laparoscopic and laparoscopic-assisted vaginal hysterectomy

STUDY OBJECTIVE

To evaluate the efficacy of laparoscopic hysterectomy and compare classic intrafascial supracervical hysterectomy (CISH) with total laparoscopic hysterectomy (TLH) and laparoscopic-assisted vaginal hysterectomy (LAVH).

DESIGN

Retrospective review (Canadian Task Force classification II-2).

SETTING

University-affiliated hospital.

PATIENTS

Six hundred fifty women who underwent laparoscopic hysterectomy from August 1993 to August 1996.

INTERVENTIONS

Charts of 231 women undergoing CISH, 102 TLH, and 317 LAVH were reviewed regarding patient characteristics, indications, uterine weight, associated procedures, estimated blood loss, operating time, and complications.

MEASUREMENTS AND MAIN RESULTS

Among the three groups, despite having the largest specimen weight and highest number of associated procedures, women undergoing CISH had the lowest complication rate and smallest amount of estimated blood loss (p <0.05). The next lowest was the TLH group (p <0.05). Although LAVH was associated with shortest operating time, there were no statistically significant differences among groups (p >0.05). The CISH group had relatively shorter operating times when compared with similar average specimen weights. Patients who underwent total hysterectomy by either TLH or LAVH had more postoperative visits than those having CISH (p <0.05, Fisher's exact test); the LAVH group had the highest number of postoperative visits. The overall complication rate appeared to be highest in the LAVH group (p <0.05, Fisher's exact test).

CONCLUSION

Among the three groups, CISH resulted in lowest blood loss and fewest complications; these values were also lower for TLH than for LAVH. If the cervix is removed along with the uterus, TLH is recommended. In our opinion, CISH is preferred in cases of benign uterine diseases because it lowers major operative complications, especially in women who have large masses with no pathologic lesions of the cervix.

Self-splicing activity of the mitochondrial group-I introns from Aspergillus nidulans and related introns from other species

The mitochondrial genome of Aspergillus nidulans contains several group-I introns. Each one has been assayed for its ability to self-splice in vitro in the absence of proteins. The intron from the apocytochrome b gene is unusual among subgroup IB4 introns in being able to self-splice, unlike a similar intron from Saccharomyces cerevisiae. The first intron in the cytochrome oxidase subunit-1 gene self-splices but only correctly completes the first step of splicing; cryptic 3' splice-sites are recognized instead and these are also used at a low frequency in vivo. The highly homologous intron from Podospora anserina completes both steps in vitro. The remaining introns do not self-splice. The correlation between subgroup category, the likely presence of specific tertiary interactions, and self-splicing activity is discussed.

Laparoscopically assisted vaginal hysterectomy

OBJECTIVE

To report our experience with laparoscopically assisted vaginal hysterectomy (LAVH) and evaluate the advantages of LAVH.

STUDY DESIGN

From January 1991 to August 1992, 176 LAVHs were performed at the Department of Obstetrics and Gynecology, College of Medicine, Chung-Ang University, Seoul, Korea. The indications for LAVH, based on the preoperative diagnosis, were uterine myomas, dysmenorrhea, chronic pelvic inflammatory disease or pelvic pain, dysfunctional uterine bleeding and cervical intraepithelial neoplasia (in order of frequency).

RESULTS

Patients had concomitant procedures, including incidental appendectomy, posterior wall repair, pelvic adhesiolysis and salpingo-oophorectomy. Bipolar forceps were used to compress and desiccate vessels. The Nd-YAG laser, scissors and/or unipolar electrode were used for tissue division, excision of adhesions and cutting. The intraoperative complications were bladder perforation, massive hemorrhage and inferior epigastric vessel injury (one case each). The postoperative complications were infection, voiding difficulty, febrile morbidity, pelvic abscess, incisional hernia, vaginal vault bleeding and peroneal nerve palsy (one case each).

CONCLUSION

Hysterectomy can be safely performed vaginally assisted by operative laparoscopy by well-trained laparoscopists, resulting in reduced surgical morbidity, blood loss, postoperative discomfort, recovery time and hospitalization.

Two group I introns with a C.G basepair at the 5' splice-site instead of the very highly conserved U.G basepair: is selection post-translational?

In virtually all of the 200 group I introns sequenced thus far, the specificity of 5' splice-site cleavage is determined by a basepair between a uracil base at the end of the 5' exon and a guanine in an intron guide sequence which pairs with the nucleotides flanking the splice-site. It has been reported that two introns in the cytochrome oxidase subunit I gene of Aspergillus nidulans and Podospora anserina are exceptions to this rule and have a C.G basepair in this position. We have confirmed the initial reports and shown for one of them that RNA editing does not convert the C to a U. Both introns autocatalytically cleave the 5' splice-site. Mutation of the C to U in one intron reduces the requirement for Mg2+ and leads to an increase in the rate of cleavage. As the C base encodes a highly conserved amino acid, we propose that it is selected post-translationally at the level of protein function, despite its inferior splicing activity.