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PubMed1999

The heterotrimeric protein Go is required for the formation of heart epithelium in Drosophila.

The gene encoding the alpha subunit of the Drosophila Go protein is expressed early in embryogenesis in the precursor cells of the heart tube, of the visceral muscles, and of the nervous system. This early expression coincides with the onset of the mesenchymal-epithelial transition to which are subjected the cardial cells and the precursor cells of the visceral musculature. This gene constitutes an appropriate marker to follow this transition. In addition, a detailed analysis of its expression suggests that the cardioblasts originate from two subpopulations of cells in each parasegment of the dorsal mesoderm that might depend on the wingless and hedgehog signaling pathways for both their determination and specification. In the nervous system, the expression of Goalpha shortly precedes the beginning of axonogenesis. Mutants produced in the Goalpha gene harbor abnormalities in the three tissues in which the gene is expressed. In particular, the heart does not form properly and interruptions in the heart epithelium are repeatedly observed, henceforth the brokenheart (bkh) name. Furthermore, in the bkh mutant embryos, the epithelial polarity of cardial cells was not acquired (or maintained) in various places of the cardiac tube. We predict that bkh might be involved in vesicular traffic of membrane proteins that is responsible for the acquisition of polarity.

Animals↗
PubMed1961

The isolated perfused bovine liver.

1. A procedure is described for surgically isolating and artificially perfusing the liver of the young bovine. Heparinized autogenous blood from the hepatectomized animal diluted with Krebs-Ringer-bicarbonate solution is employed as the perfusate. 2. This preparation has been satisfactorily reproducible in this laboratory in more than 90 separate sequential perfusions. Absence of a sensitive hepatic venous smooth musculature contributes to the ability to maintain satisfactory perfusion for as long as 24 hours. 3. The perfusate was usually maintained bacterially free for at least the first 12 hours of perfusion without the use of antibiotics. The perfusate was maintained at normal body temperature and, by varying the CO(2) content of the oxygenating gas, within a physiological pH range. The importance of these features when studying problems of intermediary biochemistry and ultrastructure is emphasized. 4. The liver of the bovine calf is sufficiently large to permit (a) simultaneous and independent perfusion through the hepatic artery and portal vein, and (b) repeated sampling of hepatic tissue without interruption of the circulation. 5. Excellent, viable condition of the isolated liver, throughout many hours of perfusion, was demonstrated by steady state of oxygen consumption, efficient clearance of bromsulphalein dye, continuous secretion of bile, constancy of blood flows and pressures, and very minimal alterations from normal in histologic and ultrastructural detail.

Animals↗
PubMed1977

Gastric cancer: current status of treatment.

While carcinomas of the stomach is decreasing in incidence in the Dnited States, it is still a major cause of cancer death. But gastric neoplasms are not decreasing in some other geographic areas. According to some studies, 30% of all cancer in the U.S.S.R. originates in the stomach. The rate of gastric neoplasms is greatest in Japan, and over 54% of all cancer in the male population arises in the stomach. The peak age for development of stomach cancer is between 70 and 80 years; over 60% of all stomach cancer is diagnosed in patients between the ages of 60 and 70, while more than 10% is found in those over 80. The main hope for cure at this time rests with surgical treatment. However, despite increased use of surgery, the 5-year survival rate of approximately 13% for patients diagnosed during 1955-59 has not improved to any degree since that time. The major drugs commonly used to treat gastric cancer are 5-fluorouracil (5-FU) and mitomycin C. Controversy still exists concerning the optimum method for administering 5-FU, the most frequently used drug in the United States. The standard loading-course method was attended by a high risk of severe toxicity and drug-related deaths. Several variations of the loading course have evolved. Currently, the Mayo Clinic group uses a 5-day course of 13.5 mg 5-FU/kg repeated every 5 weeks, with therapy interrupted if stomatitis or diarrhea develops; with this regimen the drug-related mortality rate was reported to be less than 1%. Studies have shown that 5-FU plus radiotherapy can enhance survival in patients with locally unresectable diseases. The overall objective with 5-FU is 20-25% with an average of 4-5 months' duration of response. Despite the many patients treated with 5-FU, rarely has a systematic analysis been done of factors such as age, sex, disease-free interval, histologic grade of the tumor, or sites or metastases, which might predispose to a favourable or unfavorable response. In Japan the most commonly used drug for treatment of gastric cancer is mitomycin C, the second most frequently used drug in the United States. The overall objective response rate with mitomycin C is between 20 and 30%, with the higher response rates being reported in the Japanese data. The average duration of response ranges from 1 to 3 months. The nitrosoureas [1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), 1,3-cis(2-chloroethyl)-1-nitrosourea (CCNU), and methyl CCNU (MeCCNU)] have shown some evidence of activity against gastric cancer. BCNU has yielded an objective response rate of 18% (6/33) and an average duration of response of 4.5 months in gastric cancer patients, most of whom had no prior therapy. Adriamycin recently has been shown to have some antitumor activity, with an approximate response rate of 25%. Combination approaches have been more successful in stomach cancer than in any other gastrointestinal neoplasm. The Japanese have reported higher response rates with a combination of 5-FU, mitomycin C, and cytosine arabinoside...

Adenocarcinoma↗
PubMed1986

Acute myocardial infarction: an episodic event of several coronary spasms followed by dilatation?

Acute myocardial infarction (AMI) can no longer be considered as a single event, but as a series of episodes. In most of the cases, the initial event may be the induction of a severe spasm of the coronary artery by vasoconstrictive substance released from aggregated platelets. These spasms are followed by dilatation, which is caused by substances set free from the ischemic tissue. Dilatation then results in a washing-out of vasoactive mediators (as well as myoglobin) and platelets, which is reflected as a peak in the blood myoglobin concentration-time curve. The local depletion of vasodilative metabolites allows a further contraction of the coronary vessel. A new accumulation of platelets then stimulates another spasm. This vicious circle (thrombo-ischemic re-entry-mechanism) is repeated several times and can be interrupted by the systemic administration of thrombolytic drugs (streptokinase).

Coronary Vasospasm↗
PubMed1987

Multiple sequence versions of the Oxytricha fallax 81-MAC alternate processing family.

The 81-MAC family consists of three sizes of macronuclear chromosomes in Oxytricha fallax. Clones of these and of micronuclear homologs have been classified according to DNA sequence into three highly homologous (95.9-97.9%), but distinct versions. Version A is represented by a micronuclear clone and by clones of two different-sized macronuclear chromosomes, showing that alternate processing of micronuclear DNA is responsible for the variety of sizes of macronuclear chromosomes. Three Internal Eliminated Sequences (IES's) are demonstrated in Version A micronuclear DNA. Two have been sequenced and show short, flanking direct repeats but no inverted terminal repeats. Version C micronuclear DNA has interruptions in the macronuclear homology which correspond closely to the Version A IES's. Whether they are true IES's is unknown because no Version C macronuclear DNA has been demonstrated. Version C micronuclear DNA may be "macronuclear-homologous" but "micronucleus-limited" and not "macronucleus-destined." Version B is represented by macronuclear DNA clones, but no micronuclear clones. Vegetative micronuclear aneuploidy is suggested. The possible role of micronuclear defects in somatic karyonidal senescence is discussed in light of the precise macronuclear chromosome copy controls demonstrated within the 81-MAC family. These controls apparently operate throughout karyonidal life to maintain 1) a constant absolute amount of 81-MAC sequences in the macronucleus and 2) a constant stoichiometry within the family, both according to version and chromosome size.

Animals↗
PubMed1991

Characterization of insertion sequence IS892 and related elements from the cyanobacterium Anabaena sp. strain PCC 7120.

IS892, one of the several insertion sequence (IS) elements discovered in Anabaena sp. strain PCC 7120 (Y. Cai and C. P. Wolk, J. Bacteriol. 172:3138-3145, 1990), is 1,675 bp with 24-bp near-perfect inverted terminal repeats and has two open reading frames (ORFs) that could code for proteins of 233 and 137 amino acids. Upon insertion into target sites, this IS generates an 8-bp directly repeated target duplication. A 32-bp sequence in the region between ORF1 and ORF2 is similar to the sequence of the inverted termini. Similar inverted repeats are found within each of those three segments, and the sequences of these repeats bear some similarity to the 11-bp direct repeats flanking the 11-kb insertion interrupting the nifD gene of this strain (J. W. Golden, S. J. Robinson, and R. Haselkorn, Nature [London] 314:419-423, 1985). A sequence similar to that of a binding site for the Escherichia coli integration host factor is found about 120 bp from the left end of IS892. Partial nucleotide sequences of active IS elements IS892N and IS892T, members of the IS892 family from the same Anabaena strain, were shown to be very similar to the sequence of IS892.

Amino Acid Sequence↗
PubMed1994

Deletion between direct repeats in T7 DNA stimulated by double-strand breaks.

An in vitro system based on extracts of Escherichia coli infected with bacteriophage T7 was used to study genetic deletions between directly repeated sequences. The frequency of deletion was highest under conditions in which the DNA was actively replicating. Deletion frequency increased markedly with the length of the direct repeat both in vitro and in vivo. When a T7 gene was interrupted by 93 bp of nonsense sequence flanked by 20-bp direct repeats, the region between the repeats was deleted in about 1 out of every 1,600 genomes during each round of replication. Very similar values were found for deletion frequency in vivo and in vitro. The deletion frequency was essentially unaffected by a recA mutation in the host. When a double-strand break was placed between the repeats, repair of this strand break was often accompanied by the deletion of the DNA between the direct repeats, suggesting that break rejoining could contribute to deletion during in vitro DNA replication.

Bacteriophage T7↗
PubMed1987

The site-specific ribosomal insertion element type II of Bombyx mori (R2Bm) contains the coding sequence for a reverse transcriptase-like enzyme.

Two classes of DNA elements interrupt a fraction of the rRNA repeats of Bombyx mori. We have analyzed by genomic blotting and sequence analysis one class of these elements which we have named R2. These elements occupy approximately 9% of the rDNA units of B. mori and appear to be homologous to the type II rDNA insertions detected in Drosophila melanogaster. Approximately 25 copies of R2 exist within the B. mori genome, of which at least 20 are located at a precise location within otherwise typical rDNA units. Nucleotide sequence analysis has revealed that the 4.2-kilobase-pair R2 element has a single large open reading frame, occupying over 82% of the total length of the element. The central region of this 1,151-amino-acid open reading frame shows homology to the reverse transcriptase enzymes found in retroviruses and certain transposable elements. Amino acid homology of this region is highest to the mobile line 1 elements of mammals, followed by the mitochondrial type II introns of fungi, and the pol gene of retroviruses. Less homology exists with transposable elements of D. melanogaster and Saccharomyces cerevisiae. Two additional regions of sequence homology between L1 and R2 elements were also found outside the reverse transcriptase region. We suggest that the R2 elements are retrotransposons that are site specific in their insertion into the genome. Such mobility would enable these elements to occupy a small fraction of the rDNA units of B. mori despite their continual elimination from the rDNA locus by sequence turnover.

Amino Acid Sequence↗
PubMed2000

Is there a loss of efficacy of lithium in patients treated for over 20 years?

Diminishing efficacy of lithium prophylaxis in initially well-responding patients during long-term treatment as well as after interruption of prophylaxis has been described repeatedly in the past. For the present analysis, 22 patients with bipolar and unipolar affective disorder continuously treated and documented in a specialized lithium outpatient clinic over at least 20 years were included. The cumulative affective morbidity of the first 10 years versus the second 10 years of prophylactic treatment was subjected to statistical and single-case (life chart method) analysis. There was no statistical evidence for diminishing efficacy of lithium prophylaxis. The increase in the Morbidity Index in single patients in a case-related individual approach could be revealed as not necessarily due to an alleged loss of efficacy of lithium, but more likely to be due to the atypical features in the psychopathology and course of illness.

Adult↗
PubMed1981

Acute, massive poisoning with digitoxin: report of seven cases and discussion of treatment.

Severe digitoxin poisoning in seven patients is reported. Doses taken varied from 2 to 20 mg, and maximal plasma concentrations of digitoxin from 50 to 237 nmol/L. One patient died from ventricular fibrillation, and the course in another was considerably protracted due to severe complications. The course in all patients was more dependent on underlying heart disease than on the plasma digitoxin concentration. Based on our own experiences and survey of the literature the following treatment is proposed: Gastric aspiration and lavage followed by instillation of activated charcoal should even be performed many hours after drug intake. In order to interrupt the enterohepatic circulation of digitoxin, repeated doses of charcoal should be given. Charcoal is preferable to cholestyramine because of its better tolerability. Ventricular arrhythmias should not be treated unless they are serious, because most antiarrhythmic drugs may further impede the AV-conduction. Phenytoin is the drug of choice, because the AV-conduction is less affected or even improved, and because the metabolism of digitoxin is accelerated. Conduction disturbances with bradycardia are frequently seen and may occur suddenly. Prophylactic introduction of a transvenous pacing catheter is therefore recommended as a routine procedure.

Adolescent↗
PubMedDate not supplied

A glycine substitution in the COL7A1 gene causes mild RDEB in a Pakistani family.

Pathogenic glycine substitutions can cause destabilization of the triple helix and a diverse range of heritable connective tissue disorders, dependent on the collagen gene in which the mutation occurs. Mutations in the type VII collagen gene (COL7A1) cause an inherited mechanobullous skin disease known as dystrophic epidermolysis bullosa (DEB). Typically, the dominant forms (DDEB) result from glycine substitutions within COL7A1, whereas other glycine mutations are 'silent' in the heterozygous state and produce disease only when they are homozygous. We studied three affected individuals from a large inbred Pakistani family with a history of skin fragility and scarring indicative of dystrophic EB. We identified a new glycine substitution within the collagenous region in exon 94 of the COL7A1 gene. This mutation, designated G2422V, resulted in a glycine (GGA) to valine (GTA) substitution presumably causing a destabilization of the protein by interrupting the Gly-X-Y repeats. This finding expands the allelic series of COL7A1 mutations underlying mild recessive dystrophic epidermolysis bullosa (RDEB) and sheds further light upon regions of the type VII collagen triple helix that are tolerant of heterozygous glycine substitutions.

Amino Acid Substitution↗
PubMed1990

[Clinical effects of pulsatile LH-RH administration on ovulation induction for women with various type of amenorrhea].

Using pulsatile LH-RH administration, ovulation induction was performed in women with pituitary dwarfism (PD, n = 1), isolated gonadotropin deficiency (IGD, n = 5), secondary hypothalamic amenorrhea (gestagen negative (AM2, n = 10), positive (AM1, n = 5)), polycystic ovarian disease (PCO, n = 6) and anovulatory cycle (ANOV, n = 1). Five to 20 micrograms of LH-RH was administered subcutaneously with a pulse frequency of 90 min to 2 h, in 76 treatment cycles. The ovulation rate of IGD, AM2, AM1 and PCO was 54.5, 83.3, 12.5 and 50.0%, respectively, all being significantly different from each other. In some cases, ovulation induction was repeated for several cycles without any interruption, and chronic effects of this therapy on the subsequent cycle were examined. In IGD and AM2, subsequent cycles were well stimulated, while those of PCO became refractory. These results indicate that pulsatile LH-RH administration should be the first choice of ovulation induction in IGD and AM2, and less effective in AM1 and PD. When this treatment is applied for PCO, the luteal phase should be supported by alternative methods to avoid pituitary desensitization.

Amenorrhea↗
PubMed1997

Heterochromatic Stellate gene cluster in Drosophila melanogaster: structure and molecular evolution.

The 30-kb cluster comprising close to 20 copies of tandemly repeated Stellate genes was localized in the distal heterochromatin of the X chromosome. Of 10 sequenced genes, nine contain undamaged open reading frames with extensive similarity to protein kinase CK2 beta-subunit; one gene is interrupted by an insertion. The heterochromatic array of Stellate repeats is divided into three regions by a 4.5-kb DNA segment of unknown origin and a retrotransposon insertion: the A region (approximately 14 Stellate genes), the adjacent B region (approximately three Stellate genes), and the C region (about four Stellate genes). The sequencing of Stellate copies located along the discontinuous cluster revealed a complex pattern of diversification. The lowest level of divergence was detected in nearby Stellate repeats. The marginal copies of the A region, truncated or interrupted by an insertion, escaped homogenization and demonstrated high levels of divergence. Comparison of copies in the B and C regions, which are separated by a retrotransposon insertion, revealed a high level of diversification. These observations suggest that homogenization takes place in the Stellate cluster, but that inserted sequences may impede this process.

Amino Acid Sequence↗
PubMed1985

The human ubiquitin multigene family: some genes contain multiple directly repeated ubiquitin coding sequences.

Ubiquitin coding sequences were isolated from a human genomic library and two cDNA libraries. One human ubiquitin gene consists of 2055 nucleotides and codes for a polyprotein consisting of 685 amino acid residues. The polyprotein contains nine direct repeats of the ubiquitin amino acid sequence and the last ubiquitin sequence is extended with an additional valyl residue at the C-terminal end. No spacer sequences separate the ubiquitin repeats and the coding regions are not interrupted by intervening sequences. This particular gene is transcribed since cDNAs corresponding to the genomic sequence have been isolated. At least two more types of ubiquitin genes are encoded in the human genome, one coding for an ubiquitin monomer while another presumably codes for three or four direct repeats of the ubiquitin sequence. Human DNA contains many copies of the ubiquitin sequence. Ubiquitin is therefore encoded in the human genome as a multigene family.

Amino Acid Sequence↗
PubMed1998

More than 10 years of unrecognized nosocomial transmission of legionnaires' disease among transplant patients.

OBJECTIVE: To investigate a cluster of cases of legionnaires' disease among patients at a hospital. SETTING: A university hospital that is a regional transplant center. DESIGN: Retrospective review of microbiology and serology data from the hospital laboratories and prospective surveillance via the radiology department; a case-control study and environmental sampling within the hospital and from nearby cooling towers. RESULTS: Diagnosis of seven cases of legionnaires' disease in the first 9 months of 1996 led to recognition of a nosocomial outbreak that may have begun as early as 1979. Review of charts from 1987 through September 1996 identified 25 culture-confirmed cases of nosocomial or possibly nosocomial legionnaires' disease, including 18 in bone marrow and heart transplant patients. Twelve patients (48%) died. During the first 9 months of 1996, the attack rate was 6% among cardiac and bone marrow transplant patients. For cases that occurred before 1996, intubation was associated with increased risk for disease. High-dose corticosteroid medication was strongly associated with the risk for disease, but other immunosuppressive therapy or cancer chemotherapy was not. Several species and serogroups of Legionella were isolated from numerous sites in the hospital's potable water system. Six of seven available clinical isolates were identical and were indistinguishable from environmental isolates by pulsed-field gel electrophoresis. Initial infection control measures failed to interrupt nosocomial acquisition of infection. After extensive modifications to the water system, closely monitored repeated hyperchlorinations, and reduction of patient exposures to aerosols, transmission was interrupted. No cases have been identified since September 1996. CONCLUSIONS: Legionella can colonize hospital potable water systems for long periods of time, resulting in an ongoing risk for patients, especially those who are immunocompromised. In this hospital, nosocomial transmission possibly occurred for more than 17 years and was interrupted in 1996, after a sudden increase in incidence led to its recognition. Hospitals specializing in the care of immunocompromised patients (eg, transplant centers) should prioritize surveillance for cases of legionnaires' disease. Aggressive control measures can interrupt transmission of this disease successfully.

Case-Control Studies↗
PubMed1996

Reproductive development and functions in the rat after repeated maternal deprivation stress.

The present study examines whether interruptions of maternal-neonatal behaviors may alter the maturation of reproductive organs and functions, thereby potentially confounding the interpretation of toxicity data with stress-induced responses. Sprague-Dawley rat neonates were removed from their dams for 6 hr daily beginning on Day 4 of postnatal age and continuing until Day 21. Vaginal opening and preputial separation were monitored as indices of puberty. Sperm production in the male rats, estrous cycles in the female rats, and reproductive tissues were weighed when the animals reached sexual maturity. In addition, rats were mated for the elevation of pregnancy outcomes. Maternal separation stress in itself did not appear to alter these parameters, although potential interactions of stress responses with a toxicant should still be considered.

Animals↗
PubMed2001

Distribution of FMR1 and FMR2 alleles in Javanese individuals with developmental disability and confirmation of a specific AGG-interruption pattern in Asian populations.

The number of trinucleotide repeats in the 5' untranslated regions of the FMR1 and FMR2 genes was determined by PCR in 254 Fragile XA-negative Javanese male children with developmental disabilities. The distribution of FMR1 and FMR2 trinucleotide repeat alleles was found to be significantly different in the Indonesian population with developmental disability compared to that in developmentally disabled populations in North America and Europe (p & 0.021). Sequence analysis was performed on the trinucleotide repeat arrays of the 27 individuals with FMR1 alleles in the 'grey zone' (35-54 repeats). A repeat array structure of 9A9A6A9 was found in 16 unrelated individuals with 36 repeats, confirming earlier observations in intellectually normal Japanese. We propose that this FMR1 array pattern is specific for Asian populations and that Javanese and Japanese populations arose from a single progenitor population.

Alleles↗
PubMed1994

[An instrument for hepatic artery compression in palliative treatment of liver metastases using repeated ischemia. A model and experimental study].

Method of interrupted ischaemization of the liver afflicted with metastases from colorectal cancer is not definitively evaluated yet. Using the literary reports the authors proposed (in cooperation with MEDIN) a instrument for compression of the liver artery, economically easy available. The reability of this instrument was tested in model conditions and his safety to the tested artery was proved on the experimental animal.

Animals↗