[Evaluation of the efficacy of Chinese Children's Asthma Action Plan on the long-term management of children with asthma at home]

Objective: During the COVID-19 pandemic, the electronic "questionnaire star" was employed to investigate the general situation, medication situation and pandemic impact of children diagnosed with asthma in our hospital and enrolled in the electronic platform of the Chinese Children's Asthma Action Plan (CCAAP). The internet technology and big data were used to grasp the trend and asthma control of children who had been at home for a long time due to the pandemic, so as to facilitate the management. Methods: By random cluster sampling survey method, according to the needs and medication adherence score, the electronic "questionnaire star" was designed to conduct a survey among children (0 to 14 years old) who diagnosed with asthma and joined the CCAAP on the basis of bronchial asthma medication adherence scale. Finally, the results of electronic questionnaire survey were analyzed. Results: A total of 423 questionnaires were sent out, 422 of which were valid, with an effective response rate of 99.7%. The results of questionnaire survey showed that 296 cases were male, accounting for 70.1%, and 126 cases were female, accounting for 29.9%, with an average age of (5.4±2.6) years old. The average age of males and females was (5.3±2.6) and (5.4±2.6) years old, respectively. There were more children aged ≥5 years than children who were younger than 5 years. Additionally, 13.95% of the parents thought that the pandemic had more than moderate impact on children with asthma, and 76.12% of the children were in the green zone and had no asthma attack. The proportion of green zone inhaled drugs (79.8%) was higher than yellow zone and red zone (49.8%). After using the CCAAP platform, the dissatisfaction rate was only 1.42%. Moreover, 71.87% of the children's medical expenses decreased, and the proportion of frequent use and intermittent use of antibiotics reduced, however, the proportion of occasional use and never use of antibiotics increased significantly (all P<0.05). The average score of drug compliance was 4.56, and the more frequently the platform was used, the higher the score of medication compliance was (P<0.05). Conclusions: After using CCAAP management with the aid of internet technology, children with asthma who had been isolated at home for a long time were less affected by COVID-19, with high medication compliance, generally lower medical expenses, significantly reduced use of antibiotics, and high satisfaction. This management mode provides a new idea for internet medicine.

Evaluation and comparison of the diagnostic performance of routine blood tests in predicting liver fibrosis in chronic hepatitis B infection

Background & aims: Biopsy is the gold standard for staging liver fibrosis, but it may be accompanied by complications. As an alternative, non-invasive markers such as transient elastography (for liver fibrosis) and certain combinations of routine blood markers (liver function tests, full blood count) have been developed although their clinical significance remains controversial. Here, we compare the diagnostic values of non-invasive markers for liver fibrosis in patients with chronic hepatitis B infection. Methods: Transient elastography and routine laboratory tests were performed in 196 patients. Diagnostic performances were compared and were assessed based on the area under the curve (AUC) of a receiver operating characteristic (ROC) analysis. Results: Elevated GGT to platelet ratio (GPR), the fibrosis index FIB-4 [based on age, AST, platelets and ALT], platelet to lymphocyte ratio (PLR) and total bilirubin were independent predictors of liver stiffness defined by transient elastography (all P < 0.001). The AUCs of GPR in predicting both advanced fibrosis and cirrhosis were significantly larger than that of FIB-4 (P = 0.037 and P = 0.008, respectively) and AST-to-platelet ratio index (APRI) (P = 0.008 and P = 0.005). FIB-4, APRI and red cell volume distribution width-to-platelet ratio (RPR) had similar diagnostic values in discriminating different levels of liver fibrosis. Conclusions: GPR showed the best diagnostic value and RPR and PLR are easily available and inexpensive markers in evaluating fibrosis and cirrhosis. The diagnostic values of these laboratory markers are useful in diagnosing advanced fibrosis or cirrhosis, and in confirming the different levels of liver fibrosis.

Distant metastasis in triple-negative breast cancer

Triple-negative breast cancer (TNBC) relapses more frequently than hormone receptor-positive subtypes and is often associated with poor outcomes. This retrospective study reviewed the pattern of distant metastasis with regard to survival in patients with TNBC. A total of 205 TNBC patients were analyzed. TNBC patients with lung metastases had the longest median post-metastatic OS (with 95% confidence interval) of 16.6 (10.3-22.9) months, followed by the bone, 16.3 (11.7-20.8) months, the liver, 8.9 (3.5-14.4) months, the pleura, 7.5 (2.8-12.3) months, and the brain, 4.3 (0.6-8.0) months. Kaplan-Meier plots indicated that TNBC patients with metastatic spread to brain, liver, and pleural had poorer post-metastatic OS rate than patients with lung metastases (p = 0.001, 0.004, and 0.029, respectively). Moreover, brain and liver metastases correlated significantly with poorer post-metastatic OS as compared to bone metastasis (p = 0.004 and 0.011, respectively). Route of first metastasis correlated significantly with survival of TNBC patients with brain metastases being the poorest survival indicator, followed by metastases to liver, pleura, bone, and lung.

Structure and function of a chloroplast DNA replication origin of Chlamydomonas reinhardtii

Chloroplast DNA replication in Chlamydomonas reinhardtii is initiated by the formation of a displacement loop (D-loop) at a specific site. One D-loop site with its flanking sequence was cloned in recombinant plasmids SC3-1 and R-13. The sequence of the chloroplast DNA insert in SC3-1, which includes the 0.42-kilobase (kb) D-loop region, as well as 0.2 kb to the 5' end and 0.43 kb to the 3' end of the D-loop region, was determined. The sequence is A+T-rich and contains four large stem-loop stuctures. An open reading frame potentially coding for a polypeptide of 136 amino acids was detected in the D-loop region. One stem-loop structure and two back-to-back prokaryotic-type promoters were mapped within the open reading frame. The 5.5-kb EcoRI fragment cloned in R-13 contains the 1.05-kb SC3-1 insert and its flanking regions. A yeast autonomously replicating (ARS) sequence and an ARC sequence, which promotes autonomous replication in Chlamydomonas, have been mapped within the flanking regions [Vallet, J.-M. & Rochaix, J.-D. (1985) Curr. Genet. 9, 321-324]. Both R-13 and SC3-1 were active as templates in a crude algal preparation that supports DNA synthesis. In this in vitro system, chloroplast DNA synthesis initiated near the D-loop site.

Genetic regulation of the catalase developmental program in maize scutellum: Identification of a temporal regulatory gene

Genetic and biochemical analyses suggest that the developmental program of catalase (H(2)O(2):H(2)O(2) oxidoreductase, EC 1.11.1.6) activity in maize scutella is controlled by a temporal regulatory gene (Car1) that is distinct from the structural genes thus far identified. Recombination data show that Car1 is located about 37 map units from the Cat2 structural gene on the chromosome 1S. Turnover studies indicate that Car1 may act by regulating the rate of catalase synthesis.

Protein-DNA interaction within one cloned chloroplast DNA replication origin of Chlamydomonas

A partially purified algal protein mixture which supports in vitro DNA replication consists of soluble proteins and proteins extracted from thylakoid membrane. The membrane extract is essential for the specific initiation of replication at a displacement loop (D-loop) site previously mapped by electron microscopy. D-loop site and its flanking sequences have been cloned and sequenced. In this study, fragment-retention assays using various subclones of the sequenced region indicate that some proteins in the membrane extract bind strongly and specifically with a 494 bp restriction fragment which partially overlaps the D-loop site. Protein gel analyses of the protein-DNA complex identify three DNA-binding polypeptides with apparent molecular weights of 18, 24 and 26 kDA, respectively. Treatment with chloramphenicol, an inhibitor of chloroplast protein synthesis, for 1 h has no obvious effect on the contents of the 24 or 26 kDa polypeptides but significantly reduces the content of the 18 kDa polypeptide in the membrane extract.

Repair of oxidative DNA damage: mechanisms and functions

Cellular genomes suffer extensive damage from exogenous agents and reactive oxygen species formed during normal metabolism. The MutT homologs (MutT/MTH) remove oxidized nucleotide precursors so that they cannot be incorporated into DNA during replication. Among many repair pathways, the base excision repair (BER) pathway is the most important cellular protection mechanism responding to oxidative DNA damage. The 8-oxoG glycosylases (Fpg or MutM/OGG) and the MutY homologs (MutY/MYH) glycosylases along with MutT/MTH protect cells from the mutagenic effects of 8-oxoG, the most stable and deleterious product known caused by oxidative damage to DNA. The key enzymes in the BER process are DNA glycosylases, which remove different damaged bases by cleavage of the N-glycosylic bonds between the bases and the deoxyribose moieties of the nucleotide residues. Biochemical and structural studies have demonstrated the substrate recognition and reaction mechanism of BER enzymes. Cocrystal structures of several glycosylases show that the substrate base flips out of the sharply bent DNA helix and the minor groove is widened to be accessed by the glycosylases. To complete the repair after glycosylase action, the apurinic/apyrimidinic (AP) site is further processed by an incision step, DNA synthesis, an excision step, and DNA ligation through two alternative pathways. The short-patch BER (1-nucleotide patch size) and long-patch BER (2-6-nucleotide patch size) pathways need AP endonuclease to generate a 3' hydroxyl group but require different sets of enzymes for DNA synthesis and ligation. Protein-protein interactions have been reported among the enzymes involved in BER. It is possible that the successive players in the repair pathway are assembled in a complex to perform concerted actions. The BER pathways are proposed to protect cells and organisms from mutagenesis and carcinogenesis.

Generating multiply charged protein ions by ultrasonic nebulization/multiple channel-electrospray ionization mass spectrometry

An ultrasonic nebulization/multiple channel electrospray ionization (USN/MC-ES) source, which generates multiply charged peptides and proteins ions, was developed. The source is an ultrasonic nebulizer that is connected to a multiple channel electrospray ionization source. Aerosols were formed by ultrasonically nebulizing the sample solution. The aerosols were then purged into the central channel of a seven-channel ES source via nitrogen gas. A methanol solution that contained 1% trifluroacetic acid was electrosprayed through the outlying six electrosprayers. Detection of multiply charged peptide and protein ions indicated that electrospray was generated from the charged droplet containing analyte. The sample aerosol appeared to fuse with the charged methanol droplet in the air. Then electrospray ionization of the analyte occurred from the newly formed droplet. The peptide and protein prepared in deionized water were detected by this USN/MC-ES-MS. By varying the electrospray solvents, the signals of certain components in the mixture were selectively suppressed.

Fission yeast (Schizosaccharomyces pombe) cells defective in the MutY-homologous glycosylase activity have a mutator phenotype and are sensitive to hydrogen peroxide

The modified base 7,8-dihydro-8-oxo-guanine (8-oxoG) is one of the most stable deleterious products of oxidative DNA damage because it mispairs with adenine during DNA replication. In the fission yeast Schizosaccharomyces pombe, the MutY homolog (SpMYH) is responsible for removing misincorporated adenines from A/8-oxoG or A/G mismatches and thus preventing G:C to T:A mutations. In order to study the functional role of SpMYH, an SpMYH knockout strain was constructed. The SpMYH knockout strain, which does not express SpMYH and has no A/8-oxoG glycosylase activity, displays a 36-fold higher frequency of spontaneous mutations than the wild type strain. Disruption of SpMYH causes increased sensitivity to H2O2 but not to UV-irradiation. Expression of SpMYH in the mutant cells restores the adenine glycosylase activity, reduces the mutation frequency, and elevates the resistance to H2O2. Asp172 of SpMYH is conserved in a helix-hairpin-helix superfamily of glycosylases. The SpMYHA strain expressing D172N SpMYH retained the mutator phenotype. Moreover, when D172N mutant SpMYH was expressed in the wild-type cells, the mutation frequency observed was even higher than that of the parental strains. Thus, a mutant SpMYH that retains substrate-binding activity but is defective in glycosylase activity exhibits a dominant negative effect. This is the first demonstration that a MutY homolog plays an important role in protecting cells against oxidative DNA damage in eukaryotes.

Prognostic factors of primary adenocarcinoma of the uterine cervix

OBJECTIVE

To determine which clinicopathological factors influence the prognosis of cervical adenocarcinoma.

METHODS

Three hundred and two cases of primary adenocarcinoma of the uterine cervix, treated between 1977 and 1994, were studied retrospectively. Clinical data and pathological findings with respect to primary therapy were reviewed and evaluated.

RESULTS

The 5-year survival rates for stages I, II, and III/IV were 75.9, 62.9, and 25.1%, respectively. International Federation of Gynecology and Obstetrics stage (P < 0. 0001), cell type (P = 0.0176), tumor grade (P = 0.023), lymph node status (P = 0.018), and bulky tumor (P = 0.007) were found to be independent factors using the stepwise Cox proportional hazards model. Old age (P = 0.0581), presence of hypertension (P = 0.46), diabetes mellitus (P = 0.18), obesity (P = 0.15), and oral contraceptive use (P = 0.42) were not found to adversely influence survival rates for cervical adenocarcinoma after adjusting for other covariates. Adenosquamous adenocarcinoma had a better prognosis than endocervical columnar cell adenocarcinoma in stages I and II (P = 0. 0235). Also, in cervical adenocarcinoma's early stages, multivariate modeling revealed that chances of survival were significantly better for patients treated by radical surgery than for patients treated by radiation therapy (P < 0.001).

CONCLUSIONS

Survival rates for cervical adenocarcinoma were significantly influenced by stage, histologic subtype, tumor grade, the presence of a positive lymph node, and tumor size. Although a randomized prospective study is needed, our data imply that radical surgery may be considered a better primary modality of treatment than radiation therapy for the early stages of cervical adenocarcinoma. Further, the presence of hypertension, diabetes mellitus, or obesity may not adversely influence survival rates.

The potential of serum levels of soluble tumour necrosis factor receptor I as a biochemical marker in cervical cancer

OBJECTIVES

To investigate the significance of serum levels of soluble tumour necrosis factor receptor I (sTNF-RI) as a potential biochemical marker in women with cervical cancer.

DESIGN

A prospective, case-controlled study.

PARTICIPANTS

Seventy-one women with cervical cancer and 33 women with myoma were enrolled in this study.

METHODS

Pre-operative serum levels of sTNF-RI were measured with a standard enzyme-linked immunosorbent assay utilising murine monoclonal antibody against sTNF-RI.

MAIN OUTCOME MEASURES

All data in both groups were evaluated and correlated with the pre-operative serum levels of sTNF-RI. Data analysis was carried out using ANOVA with multiple comparison and linear regression.

RESULTS

The mean serum level of sTNF-RI in the cervical cancer group was significantly lower than that in the myoma group (P < 0.001). The sTNF-RI levels decreased sequentially with disease progression from Stage Ia to IIb in women with cervical cancer. The mean serum level of sTNF-RI was also significantly lower in women with positive lymph node (P < 0.05) or recurrent cancer (P < 0.001). A negative correlation was observed between serum levels of sTNF-RI and tumour size (r = -0.622, P < 0.0001).

CONCLUSIONS

Decreased pre-operative serum levels of sTNF-RI are observed in women with cervical cancer. The results do not support that the use of sTNF-RI as a biochemical marker for cervical cancer.

A highly conserved nucleotide in the Alu domain of SRP RNA mediates translation arrest through high affinity binding to SRP9/14

Binding of the signal recognition particle (SRP) to signal sequences during translation leads to an inhibition of polypeptide elongation known as translation arrest. The arrest activity is mediated by a discrete domain comprised of the Alu portion of SRP RNA and a 9 and 14 kDa polypeptide heterodimer (SRP9/14). Although very few nucleotides in SRP RNA are conserved throughout evolution, the remarkable conservation of G24, which resides in the region of SRP9/14 interaction, suggests that it is essential for translation arrest. To understand the functional significance of the G24 residue, we made single base substitutions in SRP RNA at this position and analyzed the ability of the mutants to bind SRP9/14 and to reconstitute functional SRPs. Mutation of G24 to C reduced binding to SRP9/14 by at least 50-fold, whereas mutation to A and U reduced binding approximately 2- and 5-fold respectively. The mutant RNAs could nevertheless assemble into SRPs at high subunit concentrations. SRPs reconstituted with mutant RNAs were not significantly defective in translation arrest assays, indicating that the conserved guanosine does not interact directly with the translational machinery. Taken together, these results demonstrate that G24 plays an important role in the translation arrest function of SRP by mediating high affinity binding of SRP9/14.

The decline in human Alu retroposition was accompanied by an asymmetric decrease in SRP9/14 binding to dimeric Alu RNA and increased expression of small cytoplasmic Alu RNA

Alu interspersed elements are inserted into the genome by a retroposition process that occurs via dimeric Alu RNA and causes genetic disorders in humans. Alu RNA is labile and can be diverted to a stable left monomer transcript known as small cytoplasmic Alu (scAlu) RNA by RNA 3' processing, although the relationship between Alu RNA stability, scAlu RNA production, and retroposition has been unknown. In vivo, Alu and scAlu transcripts interact with the Alu RNA-binding subunit of signal recognition particle (SRP) known as SRP9/14. We examined RNAs corresponding to Alu sequences that were differentially active during primate evolution, as well as an Alu RNA sequence that is currently active in humans. Mutations that accompanied Alu RNA evolution led to changes in a conserved structural motif also found in SRP RNAs that are associated with thermodynamic destabilization and decreased affinity of the Alu right monomer for SRP9/14. In contrast to the right monomer, the Alu left monomer maintained structural integrity and high affinity for SRP9/14, indicating that scAlu RNA has been under selection during human evolution. Loss of Alu right monomer affinity for SRP9/14 is associated with scAlu RNA production from Alu elements in vivo. Moreover, the loss in affinity coincided with decreased rates of Alu amplification during primate evolution. This indicates that stability of the Alu right monomer is a critical determinant of Alu retroposition. These results provide insight into Alu mobility and evolution and into how retroposons may interact with host proteins during genome evolution.

Adenomyosis in the broad ligament and tamoxifen: report of a case

Adenomyosis confined to the broad ligament is extremely rare. Herein we present a case of adenomyosis in the broad ligament with unusual gross features. This 41-year-old woman had been on tamoxifen therapy for 3 years due to breast cancer. Ten months after discontinuing tamoxifen, she underwent exploratory laparotomy for a right adnexal mass suspected as ovarian malignancy. At laparotomy, the mass was located in the right broad ligament with a fibrous stalk connecting to the uterus. Total abdominal hysterectomy with bilateral salpingo-oophorectomy was performed. Histopathologic examination revealed adenomyosis with cyst formation and an unusual thick capsule. The possible effects of tamoxifen upon the uterus are discussed in this article, in view of reports of tamoxifen associated with endometrial carcinoma and endometriosis.

Prevalence of single and multiple infection with human papillomaviruses in various grades of cervical neoplasia

Evaluation of human papillomavirus (HPV) diversity in various grades of cervical lesions is helpful for understanding the characteristics of HPV infection in the pathogenesis of cervical neoplasia. A total of 227 women with normal cervices (n = 72), low- and high-grade cervical squamous intraepithelial lesions (SILs) (n = 55 and 53, respectively) and cervical carcinomas (n = 47) were screened for human papillomavirus (HPV) types 6, 11, 16 and 18 infection by the polymerase chain reaction. The prevalence of multiple HPV infections in patients with normal cervices, low-grade SILs, high-grade SILs and cervical carcinomas was 22.2%, 61.8%, 41.5% and 21.3%, respectively, while the prevalence of a single-type infection was 36.1%, 21.8%, 30.2% and 61.7%, respectively. HPV 16/11 and 16/18 were the most common combinations observed in multiple infections. Multiple HPV infections were seen most frequently in patients with low-grade SILs, and the prevalence decreased with increasing severity of cervical neoplasia. In contrast, infection with a single HPV type was most commonly observed in patients with cervical carcinoma, and the prevalence decreased with decreasing severity of cervical neoplasia. HPV 16 was the predominant single-type infection in patients with cervical carcinoma and this prevalence decreased steadily with decreasing severity of cervical neoplasia. Conversely, HPV 11 was the predominant single-type infection in patients with normal cervices. This prevalence decreased with increasing severity of cervical neoplasia. Patients with low-grade SILs had a higher prevalence of HPVs, regardless of single or multiple infection status, and larger copy numbers of virus genome were seen more frequently in patients with more severe lesions.

Monomeric scAlu and nascent dimeric Alu RNAs induced by adenovirus are assembled into SRP9/14-containing RNPs in HeLa cells

Nearly 1 000 000 copies of Alu interspersed elements comprise approximately 5% of human DNA. Alu elements cause gene disruptions by a process known as retrotransposition, in which dimeric Alu RNA is a presumed intermediate. Dimeric Alu transcripts are labile, giving rise to stable left monomeric scAlu RNAs whose levels are tightly regulated. Induction of Alu RNA by viral infection or cell stress leads to a dramatic increase in dimeric Alu transcripts, while scAlu RNA increases modestly. Each monomer of the dimeric Alu element shares sequence homology with the 7SL RNA component of the signal recognition particle (SRP). The SRP protein known as SRP9/14 is also found in a discrete complex with scAlu RNA, although whether dimeric Alu RNA is associated with SRP9/14 had been unknown. Here we show that antiserum to human SRP9 immunoprecipitates both scAlu RNA and dimeric Alu RNAs and that these RNPs accumulate after adenovirus infection, while levels of SRP9, SRP14, SRP54 and 7SL SRP RNA are unaffected. Dimeric Alu RNAs are also associated with the La protein, indicating that these are indeed nascent RNA polymerase III transcripts. This report documents that induced Alu transcripts are assembled into SRP9/14-containing RNPs in vivo while SRP levels are unchanged. Implications for Alu RNA metabolism and evolution are discussed.

The suitable treatment for adenocarcinoma in situ of uterine cervix: a report of four cases

Adenocarcinoma in situ (AIS) of the uterine cervix is a rare disease. Some authors suggested that conization is a suitable treatment for AIS as for squamous cell carcinoma in situ. However, others did not agree. Four cases of AIS, from 1984 to 1994, have been diagnosed in the Hospital of National Taiwan University. If the diagnosis of the conization specimen showed AIS, abdominal total hysterectomy was performed days thereafter. The remaining uterine cervix was checked by histopathology to determine whether it was free of cancer lesions. AIS lesions remained in the uterine cervix, as shown by conization in two cases. AIS is not like lesion as squamous cell carcinoma in situ lesion which is easy to be removed by conization. It is suggested that conization is not an adequate treatment for AIS, rather, a total hysterectomy should be performed.

Prediction of residual neoplasia based on histopathology and margin status of conization specimens

OBJECTIVE

To evaluate the status of cone margins and the severity of cervical neoplasia as predictors of residual lesions in the remaining cervices.

METHODS

We performed a 7-year retrospective study and reviewed 172 patients who had undergone cervical conization followed by subsequent hysterectomy. Pathological findings of the cone margins and residual lesions in the postcone hysterectomy specimens were recorded for analysis.

RESULTS

The prevalence rates of positive cone margins were 0, 18.6, 23.8, and 25%, respectively, in patients with low-grade squamous intraepithelial lesion (SIL) (n = 6), high-grade SIL (n = 129), stage IA1 cervical cancer (CC-IA1) (n = 21), and CC-IA2 (n = 16). The prevalence rates of positive residual lesions in postcone hysterectomy specimens were 0, 23.3, 23.8, and 43.8%, respectively, in those with low-grade SIL, high-grade SIL, CC-IA1, and CC-IA2. Residual lesions were significantly more frequently found in patients with positive cone margins (84.8%) than in those with negative margins (10.1%) (X2 = 76.81, P < 0.0001). All six patients with low-grade SIL had free cone margins. Positive predictive values of margin status for the presence of residual lesions were 83.3, 80, and 100%, respectively, in patients with high-grade SIL, CC-IA1, and CC-IA2. Only two (6.1%) of 33 patients with positive cone margins had more advanced residual lesions. Negative predictive values of margin status for the absence of residual lesions were 100, 90.5, 93.8, and 75%, respectively, in patients with low-grade SIL, high-grade SIL, CC-IA1, and CC-IA2. None of the 139 patients with negative margins had invasive residual lesion.

CONCLUSIONS

(1) The prevalence of positive cone margin and residual lesion increased with higher severity of cervical neoplasia. (2) Patients with positive cone margins had significantly higher chances of having residual lesion than those with negative margins. (3) Free cone margin does not ensure the absence of residual lesion in the remaining cervix. However, the possibility of residual invasive cancer in the remaining cervix is remote. (4) Positive cone margin does not invariably indicate the presence and persistence of more severe residual lesion. Subsequent hysterectomy may be reserved for the patient with invasive cone pathology, the patient with concomitant morbid uterine condition, or the patient who is not reliable for continuous follow-up.

Mature cystic teratoma of the ovary: a clinicopathologic study of 283 cases

BACKGROUND

Although in the English literature, much has been published about ovarian teratoma, no large series has been reported in Taiwan. Therefore a retrospective study of 283 consecutive cases of mature cystic teratomas of the ovary, operated at National Taiwan University Hospital between 1988 and 1993, was undertaken.

METHODS

This series was based on a retrospective chart study at the Department of Obstetrics and Gynecology of the National Taiwan University Hospital from 1988 to 1993. All cases included in this study were proven by pathology review. The clinical data, pathology and complications are summarized.

RESULTS

The incidence of mature cystic teratoma was 32.6% of primary ovarian neoplasm. As for the age distribution, the youngest patient was 12 years old and the oldest, 76. The largest number of cases was found in patients between the ages of 20 and 30 years; the mean age was 35.4 years. Pain, the most common complaint, was noted in 48.1% of the cases in whom it varied from a dull ache to the sharp, stabbing pain of torsion. Of greater interest was an unexpectedly high incidence (16.6%) of asymptomatic cysts found on routine physical examination. The right ovary was involved in 51.2%, the left ovary in 40.6% and bilateral ovaries were involved in 8.2%. The incidence of torsion was 9.2%, and was the highest in all complications. Ten concurrent pregnancies were noted, an incidence of 3.5%. The incidence of malignant transformation was 0.7%, with a pathology of squamous cell carcinoma.

CONCLUSIONS

Mature cystic teratom is the most common germ cell tumor and accounts for about 33% of all ovarian neoplasm They occur primarily during the reproductive years, but may occur in the postmenopausal period or in childhood. A cystic teratoma can undergo malignant transformation; it occurs most frequently in postmenopausal women, and the prognosis is poor. However, it is a rare complicaiton, with an incidence less than 1%.

Effect of liposomal composition on photoactivated liposome fusion

Bennett and O'Brien [(1995) Biochemistry 34, 3102] showed that the ultraviolet light exposure of two-component large unilamellar liposomes (LUV) composed of a 3:1 molar mixture of dioleoylphosphatidylethanolamine (DOPE) and 1,2-bis[10-(2'-hexadienoyloxy)decanoyl]-sn-glycero-3-phosphatidyl- choline (bis-SorbPC) facilitated liposome fusion. The rate and extent of liposome fusion was dependent on the extent of photopolymerization, the temperature, and the pH. Examination of the temperature dependence of fusion of photolyzed and unphotolyzed liposomes demonstrated that an enhancement of the rate of fusion occurred in the temperature range associated with the initial appearance of precursors to the inverted cubic (QII) phase [Barry et al. (1992) Biochemistry 31, 10114]. Here, the effect of the molar lipid ratio of the DOPE/bis-SorbPC liposomes on the temperature for the onset of fusion, i.e. the critical fusion temperature, was characterized by changing the relative amounts of unreactive polymorphic lipid and reactive lamellar lipid. In each case, photopolymerization of bis-SorbPC lowered the critical fusion temperature by ca. 15-20 degrees C. The photoreaction of the bis-SorbPC-containing LUV yields cross-linked poly-SorbPC, enhancing the lateral separation of the DOPE and the polylipid and causing isothermal induction of liposome fusion by lowering the temperature for the onset of fusion. Evidence is presented to support the hypothesis that the critical temperature for fusion of two LUV populations depends on the molar ratio of the monomeric lipids in heterodimers of the two LUV. This analysis indicates that the photopolymerization of appropriately designed LUV can decrease the critical fusion temperature from above to below 37 degrees C.

Risk factors for recurrence in patients with stage IB, IIA, and IIB cervical carcinoma after radical hysterectomy and postoperative pelvic irradiation

OBJECTIVE

To identify risk factors for cancer recurrence in patients with stage IB, IIA, and IIB cervical carcinoma after abdominal radical hysterectomy with pelvic lymph node dissection and postoperative pelvic irradiation.

METHODS

One hundred and eighty-seven patients with cervical carcinoma stage IB (n = 63), IIA (n = 43), and IIB (n = 81) disease who received abdominal radical hysterectomy with pelvic lymph node dissection and postoperative pelvic irradiation were followed-up for 2-10 years. The histologic type, grade, lymphovascular tumor emboli, tumor size, invasion sites, deep cervical stromal invasion, and pelvic lymph node metastases were assessed for correlation with cancer recurrence.

RESULTS

Recurrence occurred in 45 cases (24%), of whom 40 had died of the disease at the 5-year follow-up period. Univariate proportional hazards analysis revealed that the significant risk factors were adenocarcinoma, bulky tumor size (4 cm or greater), lymphovascular tumor emboli, deep cervical stromal invasion, and lymph node metastases, especially iliac nodal metastases and bilateral nodal metastases. Multivariate proportional hazards analysis showed that bulky tumor size (hazard ratio 2.34), tumor emboli (hazard ratio 2.74) and iliac nodal metastases (hazard ratio 5.31) remained significant risk factors. In contrast, no deaths occurred in the other 142 cases who did not have recurrence.

CONCLUSION

This retrospective study suggests that stage IB, IIA, and IIB cervical carcinoma cases with the above-mentioned pathologic factors are at higher risk of recurrence after abdominal radical hysterectomy with pelvic lymph node dissection and postoperative pelvic irradiation.

Triplet pregnancy complicated by intrauterine fetal death of conjoined twins from an umbilical cord accident of an acardius. A case report

BACKGROUND

Acardius is a rare occurrence in monozygotic multiple pregnancies. Triplet pregnancy composed of an acardiac fetus and a pair of conjoined twins is even more rare. The outcome of the acardius is invariably fatal, and the mortality rate of the other fetuses ranges between 50% and 70%. Perinatal mortality results mainly from complications of twin-twin transfusion syndrome.

CASE

Intrauterine fetal death, caused by an umbilical cord accident, with twisting of the acardius's cord around the fused cords of conjoined twins is reported in this present work.

CONCLUSION

An acardius should be thoroughly sought when monochorionic multiple pregnancies are found by ultrasound during prenatal care. The complications of pregnancy caused by an acardiac fetus can be avoided by using proper management.

Scalene lymph node metastases with the negative pelvic nodes in invasive cervical carcinoma

Cervical carcinoma spreads predominantly by lymphatic routes and lymph node metastases may occur even in early stages of disease. Metastases usually first appear in pelvic lymph nodes, then disseminate along the efferent lymphatic chain to the extrapelvic lymph nodes. Cases of positive lymph node metastases with negative pelvic nodes in invasive cervical carcinoma are extremely rare. We report a 50-year-old woman with bulky stage IIA cervical carcinoma who had scalene lymph node metastases in the absence of pelvic lymph node metastases after radical hysterectomy and postoperative pelvic irradiation. This rare "skipping" nodal metastasis was probably via posterior trunk lymphatic drainage of the bulky cervical carcinoma which mainly invaded the posterior vaginal cuff. Neoadjuvant or adjuvant chemotherapy is recommended to prolong survival of patients in such cases.

Comparison of detection of human papillomavirus 16 DNA in cervical carcinoma tissues by Southern blot hybridisation and nested polymerase chain reaction

An association between human papillomavirus (HPV) and cervical neoplasia has been widely reported and HPV DNA is commonly detected in cervical carcinoma tissues. However, estimates of the prevalence of HPV infection differs among various detection methods. Seventy cases of cervical carcinoma were screened for HPV 16 infection by Southern blot hybridisation (SBH) and nested polymerase chain reaction (PCR). According to SBH, the prevalences of HPV 16 DNA in stage I (n = 40) and stage II (n = 30) cervical carcinomas were 52.5 and 63.3%, respectively, and the overall prevalence was 57.1% (40 of 70). By nested PCR, the prevalences of HPV 16 infection in stage I and II cervical carcinomas were 87.5 and 93.3%, respectively, and the overall prevalence was 90.3%. The prevalence of HPV DNA detected by nested PCR was significantly greater than that detected by SBH. The combined concordance of positive and negative results between SBH and nested PCR was 61.4%. The discrepancy resulted mainly from 25 cases (35.7%) that were positive by PCR but negative by SBH. A small copy number of HPV DNA in the these 25 cases was documented by a semi-quantitative PCR method. The nested PCR was more sensitive than SBH and detected cases with low amounts of HPV DNA. The detection of HPV infection varied between these two prevailing detection methods and this should be kept in mind in assessing various epidemiological data concerning HPV infection.

Independent clinical factors which correlate with failures in diagnosing early cervical cancer

Our aim was to identify independent factors that correlated with colposcopically directed biopsy's reliability as a method for diagnosing early cervical cancer. One hundred ninety-one of a total of 2265 patients who had colposcopic examinations because of abnormal Papanicolaou smears were included in this study. These patients had all undergone a hysterectomy after being diagnosed as having cervical intraepithelial neoplasia grade III by colposcopically directed biopsy. By univariate analysis, old age (P = 0.0195), achievement of menopausal status (P = 0.0046), large lesion size (P = 0.0021), and unsatisfactory colposcopy (P = 0.0017) were found to be associated with the nondiagnosis of early cervical cancer. However, multivariate analysis using stepwise logistic regression revealed that large lesion size (P = 0.003) and unsatisfactory colposcopy (P = 0.0008) were the only independent factors that correlated with nondiagnosis. Our findings indicate that in order to reach a clear-cut diagnosis, cases with either unsatisfactory colposcopy or satisfactory colposcopy with large lesions (despite a lack of histologic evidence of invasions) should undergo a diagnostic conization.

Adenomatoid tumor of the female genital tract

OBJECTIVE

To remind gynecologists of the diagnosis of adenomatoid tumor of the female genital tract, a pathology which is often mistaken for leiomyoma, and in addition to warn of the malignant appearance of adenomatoid tumor.

MATERIALS AND METHODS

During the study period from January 1988 to May 1994, the clinical features and pathologic findings of 25 cases of adenomatoid tumor of the female genital tract were reviewed at the National Taiwan University Hospital.

RESULTS

The age of the patients ranged from 26 to 55 years with a median of 41 years. Adenomatoid tumor was an incidental finding during the surgical treatment of myoma (16 cases), cervical intraepithelial neoplasm (two cases), invasive cervical cancer (one case), adnexal cyst (five cases), and pregnancy with myoma (one case). Twenty-three cases had tumors in the uterine corpus and two in the fallopian tubes. Twenty percent of the patients had multiple tumors. Their sizes ranged from 1.0 to 8.0 cm. The case with the largest tumor measuring 8 cm in diameter is presented in detail. Its histologic, immunohistochemical and ultrastructural characteristics strongly support the mesothelial origin of adenomatoid tumor.

CONCLUSION

Some different results were obtained than those hitherto reported in the literature, such as younger age, frequency of multiple tumors, and fewer cases accompanied by leiomyomas.

Human signal recognition particle (SRP) Alu-associated protein also binds Alu interspersed repeat sequence RNAs. Characterization of human SRP9

Nearly 1 million interspersed Alu elements reside in the human genome. Alu retrotransposition is presumably mediated by full-length Alu transcripts synthesized by RNA polymerase III, while some polymerase III-synthesized Alu transcripts undergo 3'-processing and accumulate as small cytoplasmic (sc) RNAs of unknown function. Interspersed Alu sequences also reside in the untranslated regions of some mRNAs. The Alu sequence is related to a portion of the 7SL RNA component of signal recognition particle (SRP). This region of 7SL RNA together with 9- and 14-kDa polypeptides (SRP9/14) regulates translational elongation of ribosomes engaged by SRP. Here we characterize human (h) SRP9 and show that it, together with hSRP14 (SRP9/14), forms the activity previously identified as Alu RNA-binding protein (RBP). The primate-specific C-terminal tail of hSRP14 does not appreciably affect binding to scAlu RNA. Kd values for three Alu-homologous scRNAs were determined using Alu RBP (SRP9/14) purified from HeLa cells. The Alu region of 7SL, scAlu, and scB1 RNAs exhibited Kd values of 203 pM, 318 pM, and 1.8 nM, respectively. Finally, Alu RBP can bind with high affinity to synthetic mRNAs that contain interspersed Alus in their untranslated regions.

A trinucleotide repeat-associated increase in the level of Alu RNA-binding protein occurred during the same period as the major Alu amplification that accompanied anthropoid evolution

Nearly 1 million Alu elements in human DNA were inserted by an RNA-mediated retroposition-amplification process that clearly decelerated about 30 million years ago. Since then, Alu sequences have proliferated at a lower rate, including within the human genome, in which Alu mobility continues to generate genetic variability. Initially derived from 7SL RNA of the signal recognition particle (SRP), Alu became a dominant retroposon while retaining secondary structures found in 7SL RNA. We previously identified a human Alu RNA-binding protein as a homolog of the 14-kDa Alu-specific protein of SRP and have shown that its expression is associated with accumulation of 3'-processed Alu RNA. Here, we show that in early anthropoids, the gene encoding SRP14 Alu RNA-binding protein was duplicated and that SRP14-homologous sequences currently reside on different human chromosomes. In anthropoids, the active SRP14 gene acquired a GCA trinucleotide repeat in its 3'-coding region that produces SRP14 polypeptides with extended C-terminal tails. A C-->G substitution in this region converted the mouse sequence CCA GCA to GCA GCA in prosimians, which presumably predisposed this locus to GCA expansion in anthropoids and provides a model for other triplet expansions. Moreover, the presence of the trinucleotide repeat in SRP14 DNA and the corresponding C-terminal tail in SRP14 are associated with a significant increase in SRP14 polypeptide and Alu RNA-binding activity. These genetic events occurred during the period in which an acceleration in Alu retroposition was followed by a sharp deceleration, suggesting that Alu repeats coevolved with C-terminal variants of SRP14 in higher primates.

Torsion of an ovarian borderline tumor with extreme serum tumor markers: a case report

A postmenopausal woman with torsion of the left ovarian mucinous cystadenoma with borderline malignancy is reported. Extremely elevated serum tumor markers such as carcinoembryonic antigen (CEA) (398.0 ng/mL, normal < 3.0 ng/mL), carbohydrate antigen 19-9 (CA 19-9) (240 U/mL, normal < 37 U/mL) and tissue polypeptide antigen (TPA) (1,918 U/L, normal < 110 U/L) were found preoperatively. Imaging studies such as ultrasound and computed tomogram favored a diagnosis of ovarian malignancy, and advanced ovarian cancer was suspected prior to operation. Diagnosis of borderline malignancy was first made by frozen section during laparotomy. The patient recovered following simple total hysterectomy and bilateral salpingo-oophorectomy. Serum levels of the tumor markers became normal gradually following operation. To present knowledge, this is the first reported case with extremely high serum tumor markers in a postmenopausal woman with torsion of a stage-Ia ovarian mucinous cystadenoma of borderline malignancy. Rapid release of these tumor markers into circulation secondary to necrosis and degeneration of the tumor cells following torsion might account for such an unusual finding.

Leiomyosarcoma of the broad ligament: a case report and literature review

Solitary tumors of the broad ligament are rare. The most frequent solid tumor of the broad ligament is leiomyoma. Leiomyosarcoma of the broad ligament (LBL) is an extremely rare malignant tumor. Nine cases of leiomyosarcoma of the broad ligament had been reported previously. A 59-year-old woman with LBL is reported. Treatment consisted of resection and total abdominal hysterectomy with bilateral salpingo-oophorectomy. No evidence of metastasis is noted after 12 months follow-up. We conclude that the management of LBL is excision of the leiomyosarcoma as completely as possible and postoperative adjuvant chemotherapy.

Immunoelectrophoretic differentiation of alpha-fetoprotein in disorders with elevated serum alpha-fetoprotein levels or during pregnancy

Our study aims to make differential diagnosis by immunoelectrophoresis for some common conditions with elevated levels of serum alpha-fetoprotein (AFP). One hundred and nine cases with elevated AFP levels were included in this study: yolk sac tumor (n = 8), hepatocellular carcinoma (n = 26), gastric cancer (n = 12), chronic hepatitis (n = 27) and normal pregnancy (n = 36). Lectin agarose gel electrophoresis, antibody-affinity blotting, and immunoreaction were used to identify the specific patterns of AFP in the respective conditions. The results showed that there were three possible bands: L1, L2 and L3. Yolk sac tumor produced a prominent L2 band and a light L3 band. Hepatocellular carcinoma produced a prominent L1 band and a light L3 band. Gastric cancer produced only an L1 band. Chronic hepatitis had a light L1 band and a pronounced L3 band. In pregnancy, the AFP pattern is similar to that of hepatocellular carcinoma. Immunoelectrophoresis is a useful method facilitating the differentiation of AFP origins.

[Intestinal parasite and Clonorchis sinensis infection among the inhabitants in the upper stream of Taechong Dam, Kumgang (River)]

The prevalence of intestinal parasites and Clonorchis sinensis infection was observed among inhabitants in the upper stream of Kumgang (River) from January to October 1991. A total of 743 fecal specimens was examined by cellophane thick smear and formalin-ether concentration technique. The parasite positive rate including helminth eggs and protozoan cysts was 40.8%, the positive rates for every species were: Clonorchis sinensis 30.8%, Metagonimus spp. 14.5%, Fasciola spp. 0.7%, Taenia spp. 1.5%, Ascaris lumbricoides 0.4%, Enterobius vermicularis 0.1%, Hookworm 0.1%, Trichuris trichiura 1.6%, Entamoeba coli 0.7%, E. histolytica 0.3%, Endolimax nana 0.3%, Giardia lamblia 0.3% and Iodamoeba buetschlii 0.1%, respectively. The cumulative positive rate in Okchon-gun showed 51.1%, in the Kumsan-gun 50.8% and in the Muju-gun 28.6%. Through this survey, it was concluded that the soil transmitted intestinal parasites including helminthseggs and protozoan cysts have been decreased remarkably among the inhabitants along the upper stream of Taechong Dam, Kum-gang (River), on the other side, Clonorchis sinensis, Metagonimus spp. and Taenia spp. are still morderate prevalent.

Measurement of human chorionic gonadotropin by carboxyl terminal peptide assay in patients with cervical neoplasm

The aim of this study was to investigate whether human chorionic gonadotropin (hCG) is produced by preinvasive cancer and the early stages of invasive cancer. One hundred and fifty-two patients with either various grades of preinvasive cervical carcinoma or microinvasive carcinoma, and 46 normal women used as controls, were enrolled in this study. A carboxyl terminal peptide beta-hCG (CTP-beta-hCG) assay with a sensitivity of 0.2 mIU/mL was used to measure serum levels. The results showed that the serum beta-hCG levels among normal control, preinvasive carcinoma and microinvasive carcinoma patients were not statistically different. Among the factors tested, including the interval since the last menstrual period, age, menopausal status, contraception method and diagnosis, serum hCG levels only correlated with the first factor. Preinvasive cervical carcinoma and microinvasive carcinoma did not result in significantly increased hCG secretion. At present, the CTP-beta-hCG assay is of limited value in the diagnosis of these diseases.

A human Alu RNA-binding protein whose expression is associated with accumulation of small cytoplasmic Alu RNA

Human Alu sequences are short interspersed DNA elements which have been greatly amplified by retrotransposition. Although initially derived from the 7SL RNA component of signal recognition particle (SRP), the Alu sequence has evolved into a dominant transposon while retaining a specific secondary structure found in 7SL RNA. We previously characterized a set of Alu sequences which are expressed as small cytoplasmic RNAs and isolated a protein that binds to these transcripts. Here we report that biochemical purification of this protein revealed it as the human homolog of the SRP 14 polypeptide which binds the Alu-homologous region of 7SL RNA. The human cDNA predicts an alanine-rich C-terminal tail translated from a trinucleotide repeat not found in the rodent homolog, which accounts for why the human protein-RNA complex migrates more slowly than its rodent counterpart in RNA mobility shift assays. The human Alu RNA-binding protein (RBP) is expressed after transfection of this cDNA into mouse cells. Expression of human RBP in rodent x human somatic cell hybrids is associated with substantial increase in endogenous small cytoplasmic Alu and scB1 transcripts but not other small RNAs. These studies provide evidence that this RBP associates with Alu transcripts in vivo and affects their metabolism and suggests a role for Alu transcripts in translation in an SRP-like manner. Analysis of hybrid lines indicated that the Alu RBP gene maps to human chromosome 15q22, which was confirmed by Southern blotting. The possibility that the primate-specific structure of this protein may have contributed to Alu evolution is considered.

Loop electrosurgical excision procedure for conization of the uterine cervix

The application of loop electrosurgical excision procedure (LEEP), a new method of conization of the uterine cervix used to diagnose cervical intraepithelial neoplasia (CIN) or cervical cancer is presented herein. A loop electrode consists of a thin wire that allows deep excision of the transformation zone (TZ). The cone-shaped tissue removed can be examined histologically. Over a period of one year, a total of 41 cases underwent LEEP. Without anesthesia, the patients did not have any noticeable pain during the procedure. There were no complications, such as fever, wound infection, massive bleeding or cervical stenosis. In low-grade CIN, follow-up colposcopy and cytology did not show persistence or recurrence. In two cases of high-grade CIN, subsequent hysterectomy revealed residual lesions on hysterectomized specimens. LEEP is a simple and quick procedure of diagnostic conization that can be done at the first visit without major complication. If the histopathology after LEEP is moderate- to high-grade CIN or invasive cancer, the conization cannot be regarded as a sufficient therapeutic procedure, and such a patient needs further treatment.

Vulvar neoplasia associated with other primary malignancies

It is recognized that a significant number of patients with vulvar neoplasia have had previous, concurrent, or subsequent genital tract neoplasia. This has resulted in speculation that there may be a common etiology and, in particular, of the possibility of an infection element. Among 59 cases of vulvar cancer diagnosed at the National Taiwan University Hospital from 1976 to 1991, there were seven cases (12%) associated with other primary malignancies. Carcinoma of the cervix was the most frequent other primary cancer (6/7, 86%). The possible role of human papilloma virus infection in genital neoplasia is discussed.

The state of p53 in primary human cervical carcinomas and its effects in human papillomavirus-immortalized human cervical cells

Wild-type (wt) p53 acts as a tumor suppressor, while certain mutant type (mt) p53 may exhibit 'oncogenic' function. We have recently demonstrated that human papillomavirus type 18 (HPV-18) E6 can partially overcome the growth-suppressive effects of wt p53, but it remains unclear what role p53 plays in cervical carcinogenesis. In this report, we have examined nine HPV-immortalized human cervical epithelial cell lines and 13 HPV-positive and two HPV-negative primary cervical cancers for p53 mutations by polymerase chain reaction--single-strand conformation polymorphism (PCR-SSCP). None of them contained p53 mutations in exons 5-9 where most p53 mutations in human tumors have been found. The entire p53-coding region of the two HPV-negative cervical cancers was sequenced and no mutations were noted. In order to examine the effects of wt p53 and mt p53 on HPV-immortalized human cells, we transfected HPV-immortalized cell lines with wt p53 and a mt p53 (mtp53Val-135). The results indicate that HPV-immortalized cells cannot tolerate large amounts of exogenous wt p53, while mt p53Val-135 can enhance transformation of these cells. The results support the notion that inactivation of wt p53 by E6 may be important for HPV-associated transformation and also suggests that mt p53 can act as an oncogene in HPV-immoralized human cells.

Cryptococcal infection of the vagina

BACKGROUND

Cryptococcal infection is opportunistic and occurs most commonly in immunocompromised patients. Meningitis is the most frequent manifestation and causes marked morbidity and mortality. Other sites are less common. We report a case of vaginal cryptococcal infection.

CASE

A 72-year-old patient who had undergone resection of the colon for cancer 9 years earlier was noted to have a suspicious lesion on the right vaginal wall after an abnormal Papanicolaou test. Biopsy of the lesion showed findings compatible with cryptococcal infection. Serial examinations revealed no evidence of systemic infection or immunocompromised condition. Empirical treatment was tried with fluconazole. Follow-up colposcopy showed almost complete disappearance of the vaginal lesion, and histologic section and culture of the tissue failed to reveal cryptococcus.

CONCLUSION

Cryptococcal infection is rare, especially in a patient with no evidence of an immunocompromised condition. The preliminary result of fluconazole treatment was satisfactory. However, further follow-up and evaluation are needed to confirm the effectiveness of fluconazole in our patient.

A cellular protein binds B1 and Alu small cytoplasmic RNAs in vitro

B1 and Alu are sequence-homologous interspersed elements of unknown function that have expanded in the genomes of mice and humans, respectively. A minority of B1 and Alu sequences are expressed as small cytoplasmic RNAs. These RNAs have conserved a secondary structure motif also present in signal recognition particle (SRP) RNA despite substantial sequence divergence, whereas random B1 and Alu sequences have not. This RNA structure has also been conserved by the source sequences that gave rise to successive transpositions during B1 and Alu evolution. In the present work small cytoplasmic B1 and Alu RNAs synthesized in vitro were found to bind a cellular protein by mobility shift and UV cross-linking analyses. The mouse and human proteins demonstrate the same specificity to a panel of competitor RNAs. Results using mutated B1 RNA indicate that a single strand loop in the conserved Alu motif is essential for binding. Previous work by Strub et al. (Stub, K., Moss, J. B., and Walter, P. (1991) Mol. Cell. Biol. 11, 3949-3959) demonstrated that the Alu-specific protein SRP 9/14 does not footprint to this region of SRP RNA. This observation coupled with the failure of anti-SRP/9 antibodies to identify SRP 9/14 in the B1 RNA-protein complex as well as the apparent mass and other characteristics of the protein described here suggest that it is a novel B1-Alu RNA-binding protein. Conservation of primary and secondary structure by B1 and Alu small cytoplasmic RNAs as well as features of their specific expression and ability to interact with the conserved binding protein indicate that these RNAs are more homologous than previously appreciated.

Radioaerosol assessment of lung improvement in cystic fibrosis patients treated for acute pulmonary exacerbations

We compared bronchopulmonary distribution homogeneity of a radioaerosol before and after hospitalization in 20 patients with cystic fibrosis (CF) with pulmonary exacerbations in order to assess lung improvement. Deposition homogeneity was quantified in terms of skew (an index of distribution symmetry), derived from frequency distribution histograms generated from gamma camera images of the lungs following radioaerosol inhalation. Lower skew values indicate enhanced distribution homogeneity. Right lung skew (RLS) was significantly reduced following therapy (1.00 +/- 0.49 to 0.84 +/- 0.47), whereas skew in the left lung was unchanged (0.95 +/- 0.38 to 0.87 +/- 0.40). The reduction in RLS was significant in patients with Shwachman-Kulczycki (SK) clinical scores less than 50 (1.27 +/- 0.53 to 0.90 +/- 0.42), but not in patients with scores greater than 50 (0.81 +/- 0.38 to 0.80 +/- 0.52). These results indicate that treatment affected the right lung more than the left lung, particularly in patients with SK scores less than 50, and suggests that radioaerosol lung imaging may be valuable in identifying sites of impairment to be targeted during treatment. Statistically, skew was less sensitive an indicator of acute change than several other clinical indices that improved following hospital treatment.

The RNA polymerase III terminator used by a B1-Alu element can modulate 3' processing of the intermediate RNA product

The dispersion of short interspersed elements (SINEs) probably occurred through an RNA intermediate. B1 is a murine homolog of the human SINE Alu; these elements are composed of 5' G + C-rich regions juxtaposed to A-rich tracts and are flanked by direct repeats. Internal promoters direct RNA polymerase III to transcribe B1 and Alu elements and proceed into the 3' flanking DNA until it reaches a (dT)4 termination signal. The resulting transcripts contain 3'-terminal oligo(U) tracts which can presumably base pair with the A-rich tract to form self-primed templates for reverse transcriptase and retrotransposition. Nuclear extracts from mouse tissue culture cells contain an RNA processing activity that removes the A-rich and 3'-terminal regions from purified B1 RNAs (R. Maraia, Nucleic Acids Res. 19:5695-5702, 1991). In this study, we examined transcription and RNA processing in these nuclear extracts. In contrast to results with use of purified RNA, nascent transcripts synthesized in nuclear extract by RNA polymerase III are not processed, suggesting that the transposition-intermediate-like RNA is shielded from processing by a protein(s). Alteration of an AATTTT TAA termination signal to a GCTTTTGC signal activated processing by greater than 100-fold in coupled transcription/processing reactions. A similar difference was found when expression was compared in frog oocytes. No difference in processing was found if the transcripts were made by T7 RNA polymerase in the presence of the nuclear extract, indicating that the different processing effects of the two terminators were dependent on synthesis by polymerase III. The modulation of processing of B1-Alu transcripts and the potential for retrotransposition of B1 and Alu DNA sequences are discussed.

Anomalous effect of uncouplers on respiratory chain-linked transhydrogenation in Escherichia coli membranes: evidence for a localized proton pathway?

Energization of the pyridine nucleotide transhydrogenase in everted membrane vesicles from Escherichia coli JM83 was compared with the process in vesicles of the same strain transformed with the plasmid pDC21 overexpressing this enzyme. Proton translocation was assayed by the quenching of the fluorescence of the probe quinacrine. Agents able to discharge transmembrane proton gradients such as nigericin and the uncouplers 3,3',4',5-tetrachlorosalicylanilide and carbonyl cyanide m-chlorophenylhydrazone inhibited ATP-dependent transhydrogenation of NADP by NADH and discharged transmembrane proton gradients generated by transhydrogenation of AcNAD by NADPH, by oxidation of NADH, and by hydrolysis of ATP. This was observed in everted membrane vesicles of both strains JM83 and JM83pDC21. These strains differed significantly in the response of the NADH oxidation-dependent transhydrogenase. This reaction was inhibited by nigericin and uncouplers in membrane vesicles of JM83 but there was little inhibition or the reaction was stimulated in JM83pDC21, in spite of the discharge of the NADH oxidation-generated proton gradient measured by quinacrine fluorescence in the latter strain. It is proposed that the transhydrogenase is energized by direct or local (nonbulk phase) proton translocation in membranes of this strain. Uncouplers might facilitate these routes but would not discharge them. The generality of these observations was shown using other strains. NADH oxidase activity was severalfold lower in membrane vesicles of JM83pDC21 compared with JM83. The levels of ubiquinone and cytochromes, and the activities of NADH dehydrogenases I and II, and of cytochrome oxidase, were similar in the two strains. It is concluded that the NADH oxidase activity of JM83pDC21 is low because of the reduced rate of collision between electron-transferring complexes of the respiratory chain due to the large amount of transhydrogenase protein in the membranes of this strain. The large amount of transhydrogenase favors direct, nonbulk phase proton transfer. Transhydrogenase activity was stimulated by Ca2+, Mg2+, or Mn2+.

Base mismatch-specific endonuclease activity in extracts from Saccharomyces cerevisiae

An endonuclease activity (called MS-nicking) for all possible base mismatches has been detected in the extracts of yeast, Saccharomyces cerevisiae. DNAs with twelve possible base mismatches at one defined position are cleaved at different efficiencies. DNA fragments with A/G, G/A, T/G, G/T, G/G, or A/A mismatches are nicked with greater efficiencies than C/T, T/C, C/A, and C/C. DNA with an A/C or T/T mismatch is nicked with an intermediate efficiency. The MS-nicking is only on one particular DNA strand, and this strand disparity is not controlled by methylation, strand break, or nature of the mismatch. The nicks have been mapped at 2-3 places at second, third, and fourth phosphodiester bonds 5' to the mispaired base; from the time course study, the fourth phosphodiester bond probably is the primary incision site. This activity may be involved in mismatch repair during genetic recombination.

Two nicking enzyme systems specific for mismatch-containing DNA in nuclear extracts from human cells

We have identified two novel enzyme systems in human HeLa nuclear extracts that can nick at specific sites of DNA molecules with base mismatches, in addition to the T/G mismatch-specific nicking enzyme system (Wiebauer, K., and Jiricny, J. (1989) Nature 339, 234-236). One enzyme (called all-type) can nick all eight base mismatches with different efficiencies. The other (A/G-specific) nicks only DNA containing an A/G mismatch. The all-type enzyme can be separated from the T/G-specific and A/G-specific nicking enzymes by Bio-Rex 70 chromatography. Further purification on a DEAE-5PW column separated the A/G-specific nicking enzyme from the T/G-specific nicking enzyme. Therefore, at least three different enzyme systems are able to cleave mismatched DNA in HeLa nuclear extracts. The all-type and A/G-specific enzymes work at different optimal salt concentrations and cleave at different sites within the mismatched DNA. The all-type enzyme can only cleave at the first phosphodiester bond 5' to the mispaired bases. This enzyme shows nick disparity to only one DNA strand and may be involved in genetic recombination. The A/G-specific enzyme simultaneously makes incisions at the first phosphodiester bond both 5' and 3' to the mispaired adenine but not the guanine base. This enzyme may be involved in an A/G mismatch-specific repair similar to the Escherichia coli mutY (or micA)-dependent pathway.