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At least 19 recordsLinked to original sources
PubMed1992

A comparison of leakage of filling materials in demineralized and non-demineralized resected root ends under vacuum and non-vacuum conditions.

A study was conducted to compare the marginal apical leakage of root-end filling materials under vacuum and non-vacuum conditions, and to assess the effect of demineralization by application of citric acid to the root ends on the apical marginal leakage of root end filling materials. The root canals of 148 extracted human canines and premolars were handfiled and sealed with gutta-percha and Roth's 801 sealer using cold lateral condensation. The teeth were divided into 8 groups that received retrofilling materials. The materials tested were amalgam, IRM and gutta-percha/sealer with and without successive application of citric acid. Half of the specimens were placed under vacuum conditions in methylene blue dye, and the other half were placed in the dye for the same time period without exhausting air from the flask. The teeth were split longitudinally and the extent of dye penetration was determined with a stereomicroscope and eyepiece micrometer. The most evident difference in dye penetration was found between the positive control groups. Under vacuum conditions, the positive controls showed complete penetration of the unobturated canal system with dye. With passive immersion only partial penetration of the unobturated canal system occurred. Application of citric acid to the root end did not adversely affect the seal of amalgam, IRM or gutta-percha/sealer.

Acid Etching, Dental↗
PubMed1991

[A fetal extraction device used in under-equipped countries: the obstetrical vacuum extractor. Results of 393 vacuum extractions in the Maternity Hospital in Sélestat. (Reflections on the use of this device in African practice)].

The level of mortality and feto-maternal morbidity in under-equipped countries is frightening. It is important to find answers. Among these: the obstetrical Ventouse is an instrument that can be used for extracting the fetus without too much difficulty. It is relatively easy to learn and to apply as compared with forceps (so long as the mechanism by which it is used is understood). The conditions under which it can be used are well defined at present: term pregnancy, the woman must be in labour, fetal membranes must be ruptured, the cervix must be completely dilated, presentation must be cephalic and the head must be engaged. 393 Ventouse extractions were carried out between 1982 and 1988 at the Maternity Hospital of Selastat and this resulted in delivery of 393 infants in good health. No maternal or fetal mortality occurred in the series. The maternal morbidity was low at 0.76% and the fetal morbidity was only 4.7%. In view of our experience, we believe that the tendency for black women to have android pelves makes it preferable to use the Ventouse as against the forceps because it has several advantages. In view of the literature and of their practice, the authors advise that the obstetric Ventouse should be used in under-equipped countries where conditions of practice are often precarious and the team poorly qualified. This will reduce the mortality and morbidity due to delivery. Pregnant women are insufficiently educated. The quality of health personnel is inadequate. The health services are inadequate for the needs of the population.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

A randomized comparison of assisted vaginal delivery by obstetric forceps and polyethylene vacuum cup.

The assisted vaginal delivery methods of rigid obstetric forceps and polyethylene vacuum cup extraction were compared in a prospective, randomized study. The 99 women studied had all completed 35 full weeks' gestation, required attempted assisted vaginal delivery, and were randomly assigned to either attempted forceps or vacuum-assisted delivery. All presentations were cephalic, with stations ranging from +1 to +4. Neonates were evaluated at 24 hours by neonatal staff. The infants underwent intracranial ultrasound screening during the first 24 hours of life and ophthalmologic examination within 48 hours. Vaginal delivery was successful with the intended method in 83% of vacuum-assisted deliveries and in 78% of forceps deliveries (not statistically significant). Neonatal retinal hemorrhage was found in 17 and 38% (P less than .043) of the randomized forceps and vacuum deliveries, respectively. No intraventricular hemorrhage was found. Apart from associations between vacuum-assisted delivery and mild hyperbilirubinemia and neonatal retinal hemorrhage (of uncertain clinical significance), and between assisted forceps delivery and an increased potential for facial injury, neonatal outcomes did not differ significantly. Maternal outcomes also did not differ significantly. No significant differences in safety or efficacy were found between polyethylene cup vacuum extraction and rigid obstetric forceps-assisted vaginal delivery in this population of predominantly low-pelvic assisted deliveries. Patients delivered by sequential use of forceps after vacuum or by vacuum after failed forceps application did not suffer significantly increased morbidity relative to those delivered by forceps or vacuum alone. Use of alternate or sequential methods allowed an overall cesarean rate of 3% in this population.

Acid-Base Equilibrium↗
PubMed1990

A.U and G.C base pairs in synthetic RNAS have characteristic vacuum UV CD bands.

The vacuum UV CD spectra of GpC, CpG, GpG, poly[r(A)], poly[r(C)], poly[r(U)], poly[r(A-U)], poly[r(G).r(C)], poly[r(A).r(U)], and poly[r(A-U).r(A-U)] were measured down to at least 174 nm. These spectra, together with the published spectra of poly[r(G-C).r(G-C)], CMP, and GMP, were sufficient to estimate the CD changes upon base pairing for four double-stranded RNAs. The vacuum UV CD bands of poly[r(A)], poly[r(C)], and the dinucleotides GpC and CpG were temperature dependent, suggesting that they were due to intrastrand base stacking. The dinucleotide sequence isomers GpC and CpG had very different vacuum UV CD bands, indicating that the sequence can play a role in the vacuum UV CD of single-stranded RNA. The vacuum UV CD bands of the double-stranded (G.C)-containing RNAs, poly[r(G).r(C)] and poly[r(G-C).r(G-C)], were larger than the measured or estimated vacuum UV CD bands of their constituent single-stranded RNAs and were similar in having an exceptionally large positive band at about 185 nm and negative bands near 176 and 209 nm. These similarities were enhanced in difference-CD spectra, obtained by subtracting the CD spectra of the single strands from the CD spectra of the corresponding double strands. The (A.U)-containing double-stranded RNAs poly[r(A).r(U)] and poly[r(A-U).r(A-U)] were similar only in that their vacuum UV CD spectra had a large positive band at 177 nm. The spectrum of poly[r(A).r(U)] had a shoulder at 188 nm and a negative band at 206 nm, whereas the spectrum of poly[r(A-U).r(A-U)] had a positive band at 201 nm. On the other hand, difference spectra of both of the (A.U)-containing polymers had positive bands at about 177 and 201 nm. Thus, the difference-CD spectra revealed CD bands characteristic of A.U and G.C base pairing. (ABSTRACT TRUNCATED AT 250 WORDS)

Base Composition↗
PubMed1991

Gastric and colonic oxygen tension measured with a vacuum-fixed oxygen electrode.

A new electrode system for determination of visceral oxygen tension is presented. The system consists of a transcutaneous oxygen electrode (E5242 Radiometer A/S. Copenhagen), which is screwed into a suction ring and fixed to the organ by applying a vacuum. The electrode membrane is then in contact with the organ surface via a fluid layer with a thickness of a few micrometres, without interference from atmospheric air and without mechanical disturbance of the membrane. The electrode system was tested on the gastric and colonic wall in six pigs. As reference, a silicone tonometer was placed subserously beneath the vacuum-fixed electrode. The silicone tonometer was connected to a second transcutaneous oxygen electrode. The tissue oxygen tension was changed by subjecting the animals to various inspiratory concentrations of oxygen and to hypovolaemia. The oxygen tension measured by the vacuum-fixed electrode (PO2vac) was compared with the oxygen tension measured by the tonometer (PO2tono). A good correlation was demonstrated between PO2vac and PO2tono, the correlation coefficient being 0.8619, confirming that the suction-fixed oxygen electrode measures tissue oxygen. The lowest possible vacuum to hold the electrode unit in place was between 4.0 and 6.7 kPa. Provided the measuring time did not exceed 3 min. vacuum had only slight influence on the measured oxygen values. The mean change in PO2vac induced by varying the vacuum from 7 to 26 kPa, and 26 to 7 kPa, was only +0.23 kPa (-1.2 to +1.9) and +0.19 kPa (-0.3 to +1.3), respectively. The mean stabilization time, defined as the time from electrode application until achieving 95% of the equilibration value, was 66 sec (SEM, 3.4 sec) and 57 sec (SEM, 3.0 sec) on the gastric and colonic wall, respectively. The measured values of PO2vac varied significantly between different areas on the gastric wall (p less than 0.001). When several surface measurements were performed throughout the investigated area, the mean oxygen tension approached the oxygen tension measured by the tonometer. It is concluded that the vacuum-fixed electrode constitutes a reliable, easy and, noninvasive method for measurements of the oxygen tension in the gastric and colonic tissue.

Animals↗
PubMed1992

The hemodynamics of vacuum constriction erections: assessment by color Doppler ultrasound.

Duplex ultrasound with pulsed Doppler and color flow sonography were used to image the penis and conduct blood flow velocity studies in 5 patients. Cavernous body cross sectional area, cavernous artery diameters and peak systolic velocities were measured in the flaccid shaft, after transient exposure to negative pressure in a vacuum constriction device, and with a vacuum constriction device band applied to the tumescent shaft. We found that exposure to vacuum transiently increased central cavernous arterial blood flow velocities compared to baseline values in all patients. After a trial of a vacuum constriction device and application of the constricting band cavernous body cross sectional areas doubled. Despite increased cavernous arterial diameters in 4 of 5 patients and increased blood flow in all patients after vacuum-induced tumescence alone, we could not visualize arterial inflow in the penile shaft once the constricting band was in place. Color Doppler ultrasound can detect cavernous artery systolic flow as low as 2 to 9 cm. per second. Our data suggest that the erectile state maintained distal to the vacuum constriction device band is low flow and relatively ischemic.

Aged↗
PubMedDate not supplied

Instrumental (operative) vaginal deliveries: vacuum extraction compared with forceps delivery at Ilorin University Teaching Hospital, Nigeria.

In a four-year period (1984 to 1987) a total of 141 Nigerian women who had instrumental vaginal deliveries at term in the Obstetric unit of University of Ilorin Teaching Hospital, Ilorin, were studied. Out of this number 79 had forceps delivery while 62 had vacuum extraction. The forceps delivery rate had fluctuated between 0.11% and 0.46% while the vacuum extraction rate had steadily increased from 0.08% to 0.39% (Table 1) in our unit over the 4-year period. With the exception of fetal distress, there were no significant differences found in the indications for forceps delivery and vacuum extraction. The preapplication station, position and cervical dilatation differ in both groups (Table 4). There was less maternal trauma in vacuum extraction than forceps (Table 5). The vacuum extraction was more associated with cephalhaematoma and neonatal jaundice but less with neonatal mortality compared with forceps (Table 7). Vacuum extraction had gradually assumed more prominence as an alternative to midforceps delivery in our unit in the study period. There was no maternal mortality in the two groups.

Adolescent↗
PubMed1991

The management of impotence in diabetic men by vacuum tumescence therapy.

The treatment of impotence in diabetic men with vacuum tumescence therapy was studied in a specialist clinic. Of 54 diabetic men referred with impotence, seven declined treatment, three chose self-injection with papaverine, and 44 chose vacuum therapy. Patients underwent autonomic function testing (heart rate response to respiration), measurement of penile blood flow (duplex Doppler scanning), and estimation of serum prolactin and testosterone levels. After 2 months, 33 men (75%) were able to have satisfactory intercourse using vacuum therapy. Three others could produce a satisfactory erection with vacuum therapy but their partners found it unacceptable. Eight men (18%) were unable to have satisfactory intercourse; six of these were later treated by self-injection. The median frequency of use of vacuum therapy was 5.5 (1-26) times a month. Outcome was independent of penile blood flow, autonomic function or endocrine status. Impotent diabetic men should be given counselling and offered a choice of the available treatments. Vacuum tumescence therapy is an effective and simple treatment which requires little investigation.

Diabetes Mellitus↗
PubMed1992

The pliable obstetrical vacuum cup: application and opinions in The Netherlands.

A questionnaire was sent to all hospital obstetric units in The Netherlands to obtain information about the use of soft cups for vacuum extraction. Over 90% of the 156 units responded. Vacuum extraction was used twice as often as forceps for instrumental vaginal delivery. In 12 units the flexible cup was applied in the majority of vacuum extractions and without specific restrictions. In 47 units a minority of vacuum extractions was performed with a flexible cup: its use was generally restricted to anticipated easy low outlet extractions. It is concluded that in The Netherlands the flexible cup is an accepted instrument used in about 13% of vacuum extraction deliveries.

Female↗
PubMed1991

Long-term effects of vacuum and forceps deliveries.

The long-term effects of vacuum and forceps deliveries are largely unknown. We determined the long-term outcome of instrumental deliveries in 52,282 infants born in Jerusalem between 1964 and 1972. For each individual, events at birth were related to results of an intelligence test and medical examination done at 17 years of age by the Israeli Defence Forces draft board. 1747 individuals were delivered by vacuum, 937 by forceps, 47,500 by spontaneous delivery, and 2098 by caesarean section. Crude data showed that mean intelligence scores at 17 were significantly higher (p less than 0.0001) in the vacuum and forceps deliveries groups than in the spontaneous-delivery group; however, after adjustment for confounding factors by stepwise multiple regression, these differences were no longer seen. Although the forceps-delivery group had functional impairment of feet, vision, and retina compared with the spontaneous-delivery group, and the vacuum-extraction group had impairment of the legs, differences were small. Our findings suggest that infants delivered by vacuum or forceps are not at risk of physical and cognitive impairment at 17 years of age.

Adolescent↗
PubMed1991

External vacuum devices in the treatment of erectile dysfunction: a one-year study of sexual and psychosocial impact.

This prospective study assessed the sexual and psychosocial effects of 12 months' use of an external vacuum device in the treatment of erectile dysfunction. Results showed that the external vacuum device produced erections sufficient for intercourse in 87% of the men in our sample. The dropout rate was only 20% over the 12-month period. Use of the external vacuum device was associated with improvements in men's and their partners' sexual functioning. These improvements included erections of better quality, increased partner arousal, and increased frequency of orgasm and sexual satisfaction for men and women. The external vacuum device was also associated with decreases in general psychiatric symptomatology for men. Similar improvements in psychological functioning were not found for partners. Side effects and factors in patient and partner acceptance of the external vacuum device are discussed.

Adaptation, Psychological↗