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PubMed1984

Ribosomal DNA genes of Bombyx mori: a minor fraction of the repeating units contain insertions.

We have analyzed multiple recombinant DNA clones containing ribosomal RNA repeat units of the silkmoth, Bombyx mori. In combination with genomic DNA blots, analysis of these clones indicated that the rDNA repeat of B. mori is 10.8 kilobase pair in length and tandemly repeated in the genome, as reported by Manning et al. (18). However, contrary to that report, approximately 12% of the rDNA cistrons are interrupted by insertions of non-ribosomal DNA. Two classes of DNA insertions were identified. In one class the insertions are positioned in a region of the 28S coding sequence similar to that of the predominant rDNA insertions found in a variety of Dipteran and Tetrahymena species. In the second class, probable insertions are found close to the 3' terminus of the 28S coding sequence. Restriction enzyme analysis indicates that the two classes of insertions are not related.

Animals↗
PubMed1990

DNA with adenine tracts contains poly(dA).poly(dT) conformational features in solution.

The conformation of DNA's with adenine-thymine tracts exhibiting retardation in electrophoretic migration and considered as curved were investigated in solution by CD and RAMAN spectroscopy. The following curved multimers with adenine tracts but of different flanking sequences d(CA5TGCC)n, d(TCTCTA6TATATA5)n, d(GA4T4C)n yield CD spectroscopic features indicating a non-B structure of the dA.dT tract with similarities to polyd(A).polyd(T). We suggest that adenine-thymine bases in these multimers contain some of the distinctive conformational features of poly(A).polyd(T) probably with large propeller twist found by NMR (Behling and Kearns, 1987) and by X-ray diffraction on oligonucleotides containing a tract of adenines (Nelson et al. 1987, Coll et al; 1987; DiGabriele et al. 1989). Some elements of distinctive CD features of the contiguous adenines run are also observed in the straight multi-9-mer d(CA5GCC)n which lacks in-phase relation to the helical repeat. Despite the presence of the TpA step in the straight multimer d(GT4A4)n, the altered dA.dT conformation is not completely destroyed. Interruption of adenine tract by a guanine in d(CAAGAATGCC)n leads to a B-like conformation and to a normal electrophoretic mobility. The Raman spectra reveal a rearrangement of the sugar-phosphate backbone of dA.dT tract in the multimer d(CA5TGCC)n with respect to that of polydA.polydT. This is reflected in the presence of an unique Raman band associated to C2'-endo sugar with a predominant contribution of C1'-exo puckering which is exhibited by the multimer whereas two distinct Raman bands characterize poly(dA).poly(dT) backbone conformation.

Adenine↗
PubMed1987

The thematic continuity of mental sleep experience in the same night.

It has been found that the contents of mental sleep experience (MSE) in rapid eye movement (REM) sleep are often interrelated. The aim of this study was to see whether this interrelatedness is better accounted for by the hypothesis that the mental sleep experience interrupted by provoked awakening is resumed when the subject returns to sleep (resumption), or by the hypothesis that the same contents are elaborated repeatedly throughout the night (iterative processing). We also aimed to gain some information as to the processes by which contents previously stored in memory are retrieved and inserted into the current MSE. Ten subjects were awakened 4 times on each of 4 nights after 9 min of REM sleep, and the contents of all the possible pairings of reports were scored and compared with respect to the factors "night" (same/different), "report continguity" (contiguous/noncontinguous reports), "unit interrelated" (lexical/propositional), and "interrelationship" (paradigmatic/syntagmatic). Both the occurrences and the frequencies of interrelations were greater for same night pairs than for different night pairs, but without significant differences between contiguous and noncontiguous pairs: these data provide support for the iterative processing hypothesis. The units interrelated in pairs of reports are more frequently at a lexical than a propositional level and show more paradigmatic than syntagmatic interrelationships: these data suggest that the reelaboration of contents of previous MSEs occurs mainly at a local level, making for the coherence, rather than the thematic, progression of the MSE narrative.

Adult↗
PubMed2002

Emergence of drug-resistant HIV-1 variants in patients undergoing structured treatment interruptions.

We report the emergence of drug-resistant viral mutations in chronically HIV-infected individual undergoing structured treatment interruptions (STI). THe protease mutations K101E and K103N were detected at the end of the second or third STI. We concluded that the repeated abrupt termination and resumption of certain antiretroviral drug regimens during STI therapy may lead to the development of drug resistance in chronically HIV-infected individuals.

Anti-HIV Agents↗
PubMed1979

Prenatal diagnosis of polycystic kidneys and encephalocele (Meckel syndrome).

Two unrelated families are presented with repeated occurrences of a congenital syndrome of which the main stigmata were polycystic kidneys and occipital encephalocele (Meckel syndrome). Prenatal diagnosis, followed by interruption of pregnancy, was performed in one case. The diagnosis was based on an increase of amniotic alpha-fetoprotein (AFP), and on the mode of growth and cell types of cultured amniotic cells. In another similarly examined case the diagnosis was suspected, but the parents did not wish the pregnancy to be interrupted. The child was stillborn and malformed. AFP values are presented and discussed in relation to the observed malformations. Neural tube defects are associated with an increase of AFP in amniotic fluid, but, as in normal pregnancies, the values decrease with increasing gestational age. On the other hand, kidney malformations seem to be associated with AFP values which remain high or even increase with increasing gestational age.

Amniotic Fluid↗
PubMed2006

Organization of tn2610 containing two transposition modules.

Transposon Tn2610, found in a conjugative plasmid from an Escherichia coli isolate recovered at a hospital in Chiba, Japan, in 1975, was completely sequenced. Tn2610 is 23,883 bp long and is bracketed by two transposition modules, a Tn1721-like module and a Tn21-derived module, which correspond, respectively, to the long inverted repeats IRa and IRb previously described for this transposon. Although both tnpA genes are intact, only that in the Tn21-derived module (IRb) functions in the transposition, while that in the Tn1721-derived module (IRa) cannot recognize the 38-bp imperfect repeat at the end of the IRb element. Both tnpR and res are present in IRa, while the tnpR gene of IRb is interrupted by the insertion of an IS26 insertion element. The intervening region, between the res site of the Tn1721 module and IS26, carries multiple integron-associated resistance genes within a Tn21 backbone, including a region identical to that found in the genome of Salmonella enterica serovar Typhimurium DT104. These findings suggest that Tn2610 originated from Tn1721 and Tn21, with extensive recombination events with other elements which have resulted in a complex mosaic structure.

Base Sequence↗
PubMed1986

Nucleotide sequences of five IncF plasmid finP alleles.

The nucleotide sequences of five finP alleles from various IncF plasmids (finP types I to V) as well as of three finP mutations were determined and compared. The finP gene specificity could be attributed to a variable, six-to-seven-nucleotide loop located between inverted repeats, and the sequence data were consistent with the product of finP being an RNA molecule rather than a protein. The finP mutations interrupted a proposed finP promoter or destabilized a predicted stem-and-loop structure in the finP RNA molecule.

Alleles↗
PubMed1991

Tec2, a second transposon-like element demonstrating developmentally programmed excision in Euplotes crassus.

The analysis of a repetitive DNA interruption of the micronuclear precursor to a 0.85-kb macronuclear gene in the hypotrich Euplotes crassus has led to the identification of a second transposon-like element named Tec2. Two copies of this element, one inserted into the other, compose the interruption. The Tec2 element resembles the previously characterized Tec1 element in overall size, copy number, length, and extreme terminal sequence of its inverted repeats and in the apparent use of a 5'-TA-3' target site. In addition, extrachromosomal circular forms of Tec2 appear in DNA isolated from cells undergoing macronuclear development at the same time and with the same conformation as extrachromosomal circular forms of Tec1. These similarities suggest that the Tec1 and Tec2 elements may be under the same type of regulation during macronuclear development.

Animals↗
PubMed1976

Superficial carcinoma of the stomach.

Nine cases of superficial gastric carcinoma have been detected with upper gastrointestinal endoscopy in Bristol in the past two years. This contrasted with only six cases found from postoperative gastrectomy specimens examined in the previous eight years. It is often difficult to distinguish a superficial carcinoma from a benign ulcer, and endoscopic diagnosis is effective only if multiple biopsy specimens are taken. Endoscopy should also be repeated and multiple specimens taken until the lesion has healed; even malignant ulcers may heal, and any healed area that is depressed with interrupted mucosal folds should be suspected of malignancy. The endoscopic and histological appearances, the age of the patients, and the clinical behaviour of the disease resembled descriptions of the disease, principally from Japan. Superficial gastric carcinoma is probably under-diagnosed in Britain.

Aged↗
PubMed2005

[Methadone and sleep apnea syndrome].

BACKGROUND: Sleep apnea syndrome occurs when, during sleep, breathing stops for 10 seconds or longer, with an index of 5 times or more an hour. It is clinically characterized by loud snoring at night, continuous or interrupted by pauses followed by loud breathing. Sleep is fitful, broken by arousals, and yields little rest. There is daytime excessive sleepiness with repeated involuntary falling asleep, often unknown by the subject. CLINICAL DESCRIPTION: In this article, we describe an observation of central sleep apnea syndrome in a female patient receiving an opiate replacement therapy. METHOD: An analysis of the before and after methadone withdrawal polysomnograhic tracing was done for this patient. RESULTS: This diagnosis etiology and physiopathology are critically approached. Clinicians should be careful in treating induced sleep disorders in such patients. CONCLUSION: Prescribing benzodiazepines during an opiate withdrawal of the methadone type is not recommended when central apnea occurs.

Adult↗
PubMed1983

[Evaluation of postoperative radiotherapy by the moving strip technique for malignant ovarian tumor].

As a treatment for malignant ovarian tumor, whole abdominal irradiation including the upper abdomen is more useful. Between December, 1975 and November, 1980, we additionally applied whole abdominal irradiation by the moving strip technique (1,600 rad) after operation and whole pelvic irradiation (3,000 rad) to 43 cases of malignant ovarian tumor (serous cystadenocarcinoma-24, mucinous cystadenocarcinoma-7, mesodermal mixed tumor-3, clear cell carcinoma-2, endometrioid carcinoma-2, malignant granulosa cell tumor-1, malignant Brenner tumor-1 and metastatic tumor-3). Out of 10 cases with complete resection of the tumor, nine patients are surviving without recurrence, and also some advanced cases with incomplete operation have shown a remarkable reduction in the tumor size. As to complications, diarrhea during lower abdominal irradiation as well as nausea and vomiting during upper abdominal irradiation were observed, but no characteristic changes were observed upon checking peripheral blood, liver and renal function; thus most cases completed the whole therapy without interruption. Some cases that had appeared to respond favorably course showed a rapid recurrence after 1.5-2 years, so four cases were given repeated irradiation, but results were not so satisfactory. Further study of radiation and combinations with other therapies is now being tried.

Adenocarcinoma↗
PubMed1998

Central sleep apnea after interrupting longterm acetazolamide therapy.

One month administration of acetazolamide (ACET) (at sea level) improves periodic breathing and decreases the number of central apneas (CA) (De Backer et al., 1995 Am. J. Respir. Crit. Care Med. 151, 87-91) in nonhypercapnic central apnea syndrome. It remains unclear whether cessation of therapy would provoke recurrence of symptoms. In the present study we evaluated the number of CA after 1 and 6 months interruption of ACET therapy. Eight patients with central sleep apnea were included [central apnea index (CAI) > 5 or apnea and hypopnea index (AHI) > 10 and obstructive apnea index (OAI) < 5]. Polysomnography was repeated once after 1 month treatment (N2), after 1 month off treatment (N3) and after 6 months off treatment. CAI (25 +/- 10 at N1) decreased during N2 (4 +/- 2) and N3 (5 +/- 3) and remained low after N4 (3 +/- 1). However an increase in the number of obstructive apneas and central hypopneas could be observed together with a shift from central apnea to hypopnea after N4. Maybe ACET induces a long lasting resetting of the CO2 threshold which is still present after interruption of the therapy.

Acetazolamide↗
PubMed1967

Floral Inhibition of Biloxi Soybean During a 72-hour Cycle.

The inhibitory effect of light interruptions given during the photophobe phases of a 72-hour cycle was studied with Biloxi soybean [Glycine max (L.) Merr.]. The basic 72-hour cycle consisted of 8 hours of light followed by 64 hours of darkness and was repeated 7 times. Supplementary white light treatments given at the twenty-fourth and/or forty-eighth hour of the cycle (photophil phases) promoted the flowering levels of the controls and kept light treatments given at the most inhibitory points from inhibiting flowering completely. Such supplementary light treatments did not affect the time of maximum sensitivity to light interruptions. When 30-minute light breaks were used, maximum inhibition occurred at the 16-, 43-, and 63-hour points. The duration of the light breaks affected the time of maximum inhibition when given during the second photophobe phase. The time of maximum inhibition occurred earlier with 4-hour light breaks than with either 3-minute or 2-hour light interruptions.Three-minute red light interruptions produced essentially the same effect as 3-minute white light interruptions. Such treatments inhibited flowering completely in the first photophobe phase, inhibited flowering to only a small degree in the second photophobe phase, and inhibited flowering to an intermediate degree in the third photophobe phase. Far-red light interruptions strongly inhibited flowering in the first photophobe phase, especially when given early in the dark period. Three minutes of supplementary white light given at the twenty-fourth or forty-eighth hour of the cycle partially overcame the inhibitory effect of far-red light. Four hours of supplementary white light at these times completely overcame the far-red inhibition.

Journal Article↗
PubMed2005

DNA methylation and replication: implications for the "deletion hotspot" region of FMR1.

Expansion and hyper-methylation of a CGG repeat tract are the main causes of fragile X syndrome (FRAXA). In some rare instances, FRAXA patients harbor not only an expanded CGG tract, but a deletion encompassing the CGG repeat and flanking sequences as well. Through the use of an SV40 primate replication system, it was possible to determine that CpG methylation and DNA replication may actually mediate the formation of these rare events. Also, the genetically stabilizing AGG interruptions can be lost by replication-mediated CGG deletions.

Animals↗
PubMed2002

[Spondylolysis and spondylolisthesis during growth].

Spondylolysis and Spondylolisthesis present with typical age and activity-related issues: in newborns the pars interarticularis is always intact. Only bipedal ambulators develop spondylolysis, mostly during early childhood. Corresponding to the mechanical etiology, the incidence of spondylolysis is higher in athletes who repeatedly have to hyperextent and rotate their lumbar spine for example gymnasts, javelin throwers etc. Spondylolysis is one of the most frequent diagnosis among adolescents with lumbar back pain. However, most of the people with an interrupted Pars interarticularis (about 6% of the population) never become symptomatic or if they do, they respond very well to conservative treatment (adaptation of physical activity, active physical therapy and bracing). If pain persists in combination with an intact intervertebral disc of the slipped segment, we recommend a direct repair of the Pars interarticularis instead of an intersegmental fusion. Patients with low grade Spondylolisthesis (Meyerding I, II) require repeated radiological follow-up during growth because of the inherent risk of slip progression. If a slip of more than 50% is detected before the end of growth, operative treatment is indicated. High grade olisthesis (Meyerding III, IV) leads to anterior shift of the whole trunk, kyphosis of the slipped vertebra with subsequent compensatory lumbar hyperlordosis and flattening of the thoracic spine. Pelvic flexion is clinically evident. Reduction of the slipped and kyphotic vertebra with correction of the spinal, sacral and pelvic profile is recommended and preferable to simple fusion in situ.

Adolescent↗
PubMed1994

Respiratory resistance measured by flow-interruption in a normal population.

Data on reference values of total respiratory resistance (Rint) in healthy people are limited. The aim of this study was to examine the relationship between Rint and gender, height, weight, age and smoking habits. The instrument used was the Jaeger Pneumoscope with a flow interruption device. The method is based on transient interruption of airflow at the mouth for a brief period during which alveolar pressure equilibrates with mouth pressure. Measurement of mouth pressure is used to estimate alveolar pressure prior to interruption. The ratio of this to the flow prior to interruption gives airway resistance. The Rint data were correlated with height, weight, age, gender and smoking habits in 172 healthy subjects. They had a normal lung function (VC, FEV1) and no signs of pulmonary disease. The important determining factor for the value of the Rint were height and age. The mean Rint of 172 subjects was 0.38 +/- 0.17 kPa.1-1.s. The average within-subject variability of repeated measurements of Rint expressed as coefficient of variation was 14.4 +/- 6.9%. Reference equation and normal values for Rint in a healthy population are related to height and age. The measurements were obtained with a commercially available interruption technique.

Adolescent↗
PubMed2004

Randomized, controlled trial of therapy interruption in chronic HIV-1 infection.

BACKGROUND: Approaches to limiting exposure to antiretroviral therapy (ART) drugs are an active area of HIV therapy research. Here we present longitudinal follow-up of a randomized, open-label, single-center study of the immune, viral, and safety outcomes of structured therapy interruptions (TIs) in patients with chronically suppressed HIV-1 infection as compared to equal follow-up of patients on continuous therapy and including a final therapy interruption in both arms. METHODS AND FINDINGS: Forty-two chronically HIV-infected patients on suppressive ART with CD4 counts higher than 400 were randomized 1:1 to either (1) three successive fixed TIs of 2, 4, and 6 wk, with intervening resumption of therapy with resuppression for 4 wk before subsequent interruption, or (2) 40 wk of continuous therapy, with a final open-ended TI in both treatment groups. Main outcome was analysis of the time to viral rebound (>5,000 copies/ml) during the open-ended TI. Secondary outcomes included study-defined safety criteria, viral resistance, therapy failure, and retention of immune reconstitution. There was no difference between the groups in time to viral rebound during the open-ended TI (continuous therapy/single TI, median [interquartile range] = 4 [1-8] wk, n = 21; repeated TI, median [interquartile range] = 5 [4-8] wk, n = 21; p = 0.36). No differences in study-related adverse events, viral set point at 12 or 20 wk of open-ended interruption, viral resistance or therapy failure, retention of CD4 T cell numbers on ART, or retention of lymphoproliferative recall antigen responses were noted between groups. Importantly, resistance detected shortly after initial viremia following the open-ended TI did not result in a lack of resuppression to less than 50 copies/ml after reinitiation of the same drug regimen. CONCLUSION: Cycles of 2- to 6-wk time-fixed TIs in patients with suppressed HIV infection failed to confer a clinically significant benefit with regard to viral suppression off ART. Also, secondary analysis showed no difference between the two strategies in terms of safety, retention of immune reconstitution, and clinical therapy failure. Based on these findings, we suggest that further clinical research on the long-term consequences of TI strategies to decrease drug exposure is warranted.

Adult↗
PubMed1995

Repeated inescapable stress produces a neuroleptic-like effect on the conditioned avoidance response.

This study tests the hypothesis that the dopaminergic system mediates a restitutive response by decreasing its own activity in the face of events like persistent inescapable stress that threaten to interrupt organized mental activity. It is well established that neuroleptic drugs inhibit the conditioned avoidance response (CAR), but not the escape response, probably via a reduction in subcortical dopaminergic activity. We trained rats to perform the CAR and then subjected them to acute and chronic stress to determine whether this would result in inhibition of the CAR. Rats subjected to twice daily tailshock stress for 8 days showed inhibition of the CAR and a reduction in dopamine (DA) utilization in the nucleus accumbens. These findings are compatible with the hypothesis that an endogenous DA-dependent mechanism exists that mimics neuroleptic effects in the face of repeated stress. In humans this response may serve as a protection against psychotic decompensation from chronic endogenous or exogenous insult.

Animals↗