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At least 307 records · Page 17Linked to original sources
PubMed2003

Graft contraction: a comparison of acellular dermis versus hard palate mucosa in lower eyelid surgery.

PURPOSE: To compare graft contraction rates of acellular dermis versus hard palate mucosa when used as free spacer grafts in lower eyelid surgery and to provide clinical outcome data. METHODS: A prospective, nonrandomized clinical trial involving the placement of 19 spacer grafts in the lower eyelids of 14 patients was performed. Indications for spacer graft placement included lower eyelid retraction and mildly contracted socket. Patients with lower eyelid retraction also underwent an endoscopic subperiosteal midface lift. For all procedures, the height of each graft was measured during and after surgery. The amount of contraction was measured for each graft, and a mean was calculated for each spacer material. The clinical success was evaluated for all procedures, based on improvement of the functional concern being addressed. RESULTS: The mean graft contraction rate was 57% for the acellular dermis and 16% for the hard palate mucosal grafts (P <0.005). Of the 7 procedures using acellular dermis for lower eyelid retraction, 6 were considered a success, and 1 was considered a partial success. Of the 6 procedures using hard palate for lower eyelid retraction, 5 were considered a success, and 1 was considered a failure unrelated to the graft. Of the 5 procedures with acellular dermis used for mildly contracted socket, 2 were considered a success, 2 were considered a partial success, and 1 was considered a failure because of graft contraction. The one case using hard palate for mildly contracted socket was considered a success. CONCLUSIONS: Acellular dermis contracts significantly more than hard palate mucosa when used as a lower eyelid spacer graft. Acellular dermis and hard palate mucosa were both associated with a high rate of clinical success in all categories except for patients with a mildly contracted socket who received acellular dermis; more than 60% of these patients (n=5) had only partial success or failure caused by graft contraction.

Adult↗
PubMed1982

Restorative resins: hardness and strength vs. quantity of remaining double bonds.

It has been hypothesized that the Wallace indentation hardness of smooth surface resins is a factor of prime importance for the abrasion by food of Class 1 restorations. In the present work factors affecting the hardness of polymers were investigated. In addition the tensile strength of composite resins was measured and related to the catalytic system of the polymer. It was found that for a given composition of the monomer the Wallace hardness number increased with increasing content of inhibitor, decreased with increasing content of peroxide, and was unaffected by changes in the content of amine. The hardness was well correlated with the quantity of double bonds remaining in the polymer. BISGMA-based polymers showed no variation in hardness when the originating monomer varied with respect to content of a bi- or a trifunctional diluting monomer. Light-polymerized polymers were relatively hard as compared to chemically cured materials of adequate setting time. The tensile strength of composite resins was predominantly determined by the monomer content of peroxide and increased herewith. The tensile strength was well correlated with the quantity of remaining double bonds in the constituting polymer.

Bisphenol A-Glycidyl Methacrylate↗
PubMed2005

Effect of a light-emitting diode on composite polymerization shrinkage and hardness.

PURPOSE: This study evaluated the effect of light-emitting diodes (LEDs) on polymerization shrinkage and bottom-to-top hardness ratios of composites. MATERIALS AND METHODS: Six LEDs (Elipar FreeLight, 3M ESPE, St. Paul, MN, USA; Versalux, Centrix, Shelton, CT, USA; Ultra-Lume LED2, Ultradent, South Jordan, UT, USA; Zap LED only, CMS-Dental/Soft-Core Texas, North Richland Hills, TX, USA; Zap dual light; and L.E. Demetron I, Kerr Manufacturing Inc., Orange, CA, USA) and a quartz-tungsten-halogen (QTH) light (Optilux 501, Kerr Manufacturing Inc.) were tested. Ten specimens each of a microhybrid (Point 4, Kerr Manufacturing, Inc.) and a hybrid (Filtek Z250, 3M ESPE, St. Paul, MN, USA) composite, measuring 2 mm thick by 5 mm in diameter, were polymerized using each of the lights. Linear shrinkage was recorded using a contactless displacement instrument. Ten specimens were also polymerized with each light to determine the Knoop hardness number (KHN) at the top and bottom surfaces. RESULTS: For the microhybrid, Zap dual light had the least volumetric shrinkage 2.08% (+/- 0.33) and Elipar FreeLight had the highest 3.02% (+/- 0.73). There was no significant difference (p < or = .05) in shrinkage for the LEDs when compared with the Optilux 501. The hybrid showed the least amount of shrinkage with the L.E. Demetron I, 1.42% (+/- 0.12), and the greatest with the Zap dual light, 2.47% (+/- 0.31). The Ultra-Lume LED2 (p < or = .05) and Zap LED and dual light (p < or = .001) had significantly greater shrinkage than did the Optilux 501. Zap LED had the lowest depth of cure with a bottom KHN of 11.46 (+/- 2.71) and 33.62 (+/- 3.57) for the microhybrid and hybrid, respectively. The L.E. Demetron I had the highest bottom hardness value for the microhybrid, with a value of 40.65 (+/- 1.50). The Optilux 501 had the highest bottom hardness value for the hybrid, with a value of 62.03 (+/- 0.82). The Zap LED and dual light and Versalux lights had significantly lower bottom-to-top hardness ratios than did the QTH (p < or = .001) with the microhybrid. CONCLUSIONS: There was no statistically significant difference in shrinkage for the microhybrid with any of the lights tested. The hybrid, however, showed significantly less shrinkage with the halogen compared with the Ultra-Lume LED2 and Zap LED and dual light. All LEDs had equal or lower bottom hardness values than did the QTH, except for L.E. Demetron I with the microhybrid.

Composite Resins↗
PubMed1998

Hardness and strength of endodontic instruments made from NiTi alloy.

Scant information could be found in the dental literature on the hardness or strength of the materials in nickel-titanium (NiTi) root canal instruments. Hardness testing is a convenient method for examining these products and strength properties can be deduced from strength-hardness data. The Vickers Hardness was determined for NiTi root canal files and reamers from five manufacturers for sizes 15, 25 and 40. Significant differences in hardness were found between manufacturers, with values ranging from 296 to 349. Some differences were found between the different sizes from each manufacturer, but these were generally not statistically significant. These values obtained for NiTi instruments are lower than the softest stainless steel files previously examined (296-347 cf. 403-651), and below the hardness required for many cutting instruments (550-650). The values obtained suggest that NiTi instruments may not be as sharp as, and become blunt more easily than, stainless steel instruments. The strengths are expected to be in the lower range of those for stainless steel instruments.

Analysis of Variance↗
PubMed1998

Induction of Ca2+-calmodulin signaling by hard-surface contact primes Colletotrichum gloeosporioides conidia to germinate and form appressoria.

Hard-surface contact primes the conidia of Colletotrichum gloeosporioides to respond to plant surface waxes and a fruit-ripening hormone, ethylene, to germinate and form the appressoria required for infection of the host. Our efforts to elucidate the molecular events in the early phase of the hard-surface contact found that EGTA (5 mM) and U73122 (16 nM), an inhibitor of phospholipase C, inhibited (50%) germination and appressorium formation. Measurements of calmodulin (CaM) transcripts with a CaM cDNA we cloned from C. gloeosporioides showed that CaM was induced by hard-surface contact maximally at 2 h and then declined; ethephon enhanced this induction. The CaM antagonist, compound 48/80, completely inhibited conidial germination and appressorium formation at a concentration of 3 microM, implying that CaM is involved in this process. A putative CaM kinase (CaMK) cDNA of C. gloeosporioides was cloned with transcripts from hard-surface-treated conidia. A selective inhibitor of CaMK, KN93 (20 microM), inhibited (50%) germination and appressorium formation, blocked melanization, and caused the formation of abnormal appressoria. Scytalone, an intermediate in melanin synthesis, reversed the inhibition of melanization but did not restore appressorium formation. The phosphorylation of 18- and 43-kDa proteins induced by hard-surface contact and ethephon was inhibited by the treatment with KN93. These results strongly suggest that hard-surface contact induces Ca2+-calmodulin signaling that primes the conidia to respond to host signals by germination and differentiation into appressoria.

Amino Acid Sequence↗
PubMed2006

Vickers hardness of cast commercially pure titanium and Ti-6Al-4V alloy submitted to heat treatments.

The purpose of this study was to evaluate the effect of heat treatments on the Vickers hardness of commercially pure titanium and Ti-6Al-4V cast alloys. Six-millimeter-diameter cylindrical specimens were cast in a Rematitan System. Commercially pure titanium and Ti-6Al-4V alloy specimens were randomly assigned to 3 groups (n=10) that received the following heat treatments: control (no heat treatment); treatment 1 (T1): heating at 750 degrees C for 2 h; and treatment 2 (T2): annealing at 955 degrees C for 1 h and aging at 620 degrees C for 2 h. After heat treatments, the specimens were embedded in acrylic resin and their surface was ground and polished and hardness was measured. Vickers hardness means (VHN) and standard deviations were analyzed statistically by Kruskal-Wallis test at 5% significance level. For commercially pure titanium, Vickers hardness means of group T2 (259.90 VHN) was significantly higher than those of the other groups (control--200.26 VHN and T1--202.23 VHN), which presented similar hardness means to each other (p>0.05). For Ti-6Al-4V alloy, statistically significant differences were observed among the three groups: T2 (369.08 VHN), T1 (351.94 VHN) and control (340.51 VHN) (p<0.05). The results demonstrated different hardness of CP Ti and Ti-6Al-4V when different heat treatments were used. For CP Ti, VHN means of T2 group was remarkably higher than those of control and T1 group, which showed similar VHN means to each other. For Ti-6Al-4V alloy, however, VHN means recorded for each group may be presented as follows: T2>T1>control.

Alloys↗
PubMedDate not supplied

The influence of chemical activation on hardness of dual-curing resin cements.

During the cementation of metallic restorations, the polymerization of dual-curing resin cements depends exclusively on chemical activation. This study evaluated the influence of chemical activation compared with dual-curing (chemical and light activation), on the hardness of four dual-curing resin cements. In a darkened environment, equal weight proportions of base and catalyst pastes of the cements Scotchbond Resin Cement, Variolink II, Enforce and Panavia F were mixed and inserted into moulds with cavities of 4 mm in diameter and 2 mm in height. Subsequently, the cements were: 1) not exposed to light (chemical activation = self-cured groups) or 2) photoactivated (dual-curing = dual-cured groups). The Vickers hardness number was measured at 1 hour, 24 hours and 7 days after the start time of cements' spatulation. For all the cements, the hardness values of self-cured groups were lower than those of the respective dual-cured groups at 1 hour and 24 hours. At 7 days, this behavior continued for Variolink II and Panavia F, whilst for Scotchbond Resin Cement and Enforce there was no statistical difference between the two activation modes. All cements showed a significant increase in their hardness values from 1 hour to 7 days for both activation modes. Of the self-cured groups, Scotchbond Resin Cement and Variolink II presented the highest and the lowest hardness values, respectively, for all three times tested. Within the limitations of this study, up to the time of 24 h, chemical activation alone was unable to promote similar hardness as to that obtained with dual-curing.

Analysis of Variance↗
PubMed2006

[Shock absorption of mouthguard materials--influence of temperature conditions and shore hardness on shock absorption].

PURPOSE: To consider changes in the physical properties of mouthguard materials with the change of temperature, shock-absorbing examination and Shore hardness measurement of existing MG materials and other elastic materials were carried out. METHODS: Both examinations were done under two temperature conditions: at room temperature (25 degrees C) and simulated intraoral temperature (37 degrees C). In addition, a comparative study of the relation between Shore hardness and shock absorption of the materials was made. A self-made drop impact machine was used for the shock-absorbing examination. The thickness of a sample was assumed to be 3 mm. The loading was applied by dropping 3 kinds of steel ball, phi 10 mm (4.0 g), phi 15 mm (13.7 g), and phi 20 mm (32.6 g) from a height of 60 cm. The shock absorption of all materials was compared by the maximum impact force. Shore hardness was measured based on the JIS standard. RESULTS: The shock absorption of each material showed a different tendency depending on the loading condition. Furthermore, the shock absorption of the same material showed different results depending on the temperature condition. Shore hardness measurements tended to show low values with the condition of 37 degrees C for all materials. CONCLUSION: From the relation between shock absorption and Shore hardness, it was confirmed that there is a correlation between hardness and the maximum impact force in the materials that showed shock absorption by elastic deformation. Some materials showed high shock absorption compared with existing MG materials.

Hardness↗
PubMed1996

Influence of storage humidity on hardness of light-cured glass polyalkenoate cements.

The influence of storage in various environments on the hardness of four commercial light-cured glass polyalkenoate cements and one conventional glass polyalkenoate cement was investigated. Specimens with or without light exposure were stored for 7 days in different humidity conditions. A hardness tester with a diamond indenter point was used and Vickers hardness numbers under minor load conditions were determined. Non-light-exposed specimens did not increase in hardness in either dry or wet conditions. Light-exposed specimens became harder with time in dry conditions. Light-exposed specimens stored in wet conditions hardened only slightly. To investigate the effects of humidity, some light-exposed specimens stored first in wet conditions were stored another 7 days in dry conditions. They became as hard as those first stored in dry conditions for 7 days. It is concluded that the hardness of these cements corresponds with the humidity of the storage environment.

Acrylic Resins↗
PubMedDate not supplied

Effects of cyclic temperature changes on hardness of composite restoratives.

The clinical durability of some composite restorative materials may be significantly affected by cyclic temperature changes. This study investigated the effects of cyclic temperature changes on surface hardness of four commercial composite resins (Silux, Z100, Ariston and Surefil). Eighteen specimens of each material were divided into three treatment groups comprising a control and two different thermal cycling regimes. Control specimens were stored in distilled water at 35 degrees C for 178 hours. Thermal cycled specimens were stored in distilled water at 35 degrees C for 173 hours and subjected to five hours (300 cycles) of a thermal cycling regime consisting of the cycle ABAC, where A and B represent the fixed temperatures of 35 degrees C (28 seconds) and 15 degrees C (two seconds) and C, depending on the treatment group, either 45 degrees C or 60 degrees C (two seconds). All specimens were subsequently subjected to hardness testing (KHN) using a digital microhardness tester (load = 500 gf; dwell time = 15 seconds). Results were analyzed using ANOVA/Scheffe's test (p<0.05). The effect of thermal cycling on hardness was material-dependent. While thermal cycling significantly increased the surface hardness of Z100 and Surefil, it significantly decreased the hardness of Ariston. The hardness of Silux was not significantly affected by cyclic temperature changes. For all treatment groups, Z100 was significantly harder than the other composite resins evaluated and Surefil was significantly harder than Silux and Ariston. For both thermal cycled groups, Silux was significantly harder than Ariston.

Analysis of Variance↗
PubMed2005

The effect of bleaching agents on the surface hardness of tooth colored restorative materials.

AIM OF THE STUDY: The aim of this study was to evaluate the effect of at-home (Opalesence/Dr. kit 15%, Ultradent, Products, Inc. South Jordan, UT, USA) and in-office (Superoxol 35%, Sultan Chemists, Inc., Englewood, NJ, USA) bleaching on the surface hardness of the following tooth colored restorative materials: composite resin, Point-4 (P4), Kerr Corporation, Orange, CA, USA; ormocer, Admira (AD),VOCO, Germany; compomer Dyract AP (DY), Dentsply DeTrey GmbH, Germany; and resin modified glass ionomer cement, Fuji II LC (FL), GC Corporation, Japan. METHODOLOGY: Sixty specimens were prepared; 15 specimens of each material (each group n = 5, control after 15 days, at-home and in-office). All specimens were stored in distilled water at room temperature for 24 hrs before testing. A universal testing machine (Micromet 2100 series micro hardness testers) was used for testing Vicker's surface hardness for the three groups for every tested material. All results were statistically analyzed with one way analysis of variance (ANOVA), Post hoc Tukey HSD tests (P < 0.05), and percentage changes for Tukey. RESULTS: All the tested materials showed an increase in Vicker's surface hardness between base line (24 hrs) and the control group after 15 days storage in distilled water except DY which showed a decrease in surface hardness. All tested materials showed a decrease in surface hardness from control group after 15 days and both at-home and in-office bleaching agents except DY which showed increased values. SIGNIFICANCE: At-home as well as in-office bleaching agents have a softening effect on some tooth colored restorative material, and the patient must be aware before using them.

Analysis of Variance↗
PubMed1990

[A reliable method for evaluating the masticatory function in complete denture wearers, concerning a masticatory function evaluation chart based on food hardness].

The purpose of this study was to construct an evaluation chart to objectively and simply determine the extent of the masticatory function of complete denture wearers in daily clinical practice, and to describe the chart's clinical application. 58 different types of food were selected according to two criteria: their frequency of ingestion by complete denture wearers, and their convenience for determining the masticatory function. Then an anatomical artificial porcelain set of dentures was used to bite each food item, using only bicuspids and molars. Dentures were installed on an Instron Universal Testing Instrument to compression-cut the food. Food requiring the highest pressure was considered the hardest food. Then the masticatory function evaluation chart was constructed by using the hardness of the food as an index of relative masticatory difficulty. Using this chart, 95 complete denture wearers were tested to determine the masticatory function of their dentures. The following results were obtained: 1. The mean hardness of the 58 food items tested was 7.85 +/- 11.29 kg. The mean hardness of the 38 food items frequently ingested by complete denture wearers was 5.24 +/- 5.41 kg. 2. The differences in hardness of the foods tested were statistically processed, and the 58 food items were classified into 5 groups (I-V). This five-fold classification was used as a range for determining masticatory function. 3. A correlation coefficient of -0.697 (p less than 0.01) was found between the hardness of the food and the ease of eating the food. 4. A correlation coefficient of 0.548 (p less than 0.01) was found between the hardness of the food and the frequency of ingestion. 5. The masticatory function was determined on a 5-point scale from A to E according to the total number of food types that the subjects said that they could eat easily. The masticatory function increased progressively from A to E. The results of determining the masticatory function of the 95 complete denture wearers were as follows: Rank A 1.1%, B 10.5%, C 34.7%, D 29.5% and E 24.2%. 6. Persons who evaluated their own dentures positively comprised 86.0% of ranks D and E. On the other hand, persons who evaluated their own denture negatively were widely distributed from rank A through E, indicating that there were considerable individual differences. 7. It was concluded that the masticatory function evaluation chart was a reliable means of objectively and simply determining the masticatory function of complete denture wearers.

Bite Force↗
PubMed2006

Detection of masses and microcalcifications of breast cancer on digital mammograms: comparison among hard-copy film, 3-megapixel liquid crystal display (LCD) monitors and 5-megapixel LCD monitors: an observer performance study.

The purpose of the study was to compare observer performance in the detection of masses and microcalcifications of breast cancer among hard-copy reading and soft-copy readings using 3-megapixel (3M) and 5-megapixel (5M) liquid crystal display (LCD) monitors. For the microcalcification detection test, we prepared 100 mammograms: 40 surgically verified cancer cases and 60 normal cases. For the mass detection test, we prepared 100 mammograms: 50 cancer cases and 50 normal cases. After six readers assessed both microcalcifications and masses set for each modality, receiver operating characteristic (ROC) analysis was performed. The average A(z)s for mass detection using a hard copy and 3M and 5M LCD monitors were 0.923, 0.927 and 0.920, respectively; there were no significant differences. The average A(z) for microcalcification detection using hard copy, 3M and 5M LCD monitors was 0.977, 0.954 and 0.972, respectively. There were no significant differences, but the P-values between the hard copy and 3M LCD monitor and that between the 3M and 5M LCD monitor were 0.08 and 0.09, respectively. In conclusion, the observer performances for detecting masses of breast cancers were comparable among the hard copy and two LCD monitors; however, soft-copy reading with a 3M LCD monitor showed slightly lower observer performance for detecting microcalcifications of breast cancers than hard-copy or 5M LCD monitor reading.

Adult↗
PubMed1978

Biochemical significance of the hard and soft acids and bases principle.

The hard and soft acids and bases (HSAB) principle, which states that hard acids bind preferentially to hard bases and soft acids to soft bases, may serve to assess specific chemico-biological interactions. As living systems are composed mainly of "hard" elements, molecular events taking place within the cell are dominated by "hard-hard interactions". On this premise, it becomes likely that extraneous "soft" agents are particularly injurious to life. In the HSAB context a selected number of variegated phenomena are briefly discussed qualitatively; these include biocidal actions, heavy metal poisoning, chemical carcinogenesis, some enzymic reactions, and nucleic acid complexations. Although the HSAB principle cannot be used as a tool for mechanistic explanations of biochemical processes, it may provide clues to likely target molecules and the loci of action.

Acids↗
PubMed1990

Trace metal lung disease: in vitro interaction of hard metals with human lung and plasma components.

Hard metal pneumoconiosis is an occupational pulmonary disease caused by long-term exposure to dust produced in the hard metal industry. In vitro experiments have been carried out to study the solubility and metabolic behaviour in human lung tissue and plasma of hard metal alloy constituents such as cobalt, tungsten, tantalum, titanium and niobium. The experiments were carried out using 60Co, 187W, 182Ta, 44Ti and 95Nb radiotracers in combination with neutron activation, radio-release tests and gel filtration techniques. Leaching experiments from neutron-irradiated hard metal dust showed that cobalt was highly soluble, especially in the lung cytosol and plasma, in comparison with tantalum and tungsten. The gel filtration experiments showed three biochemical pools of cobalt in both lung and plasma components, in accordance with the hypothesis that cobalt represents the allergic factor in the development of hard metal disease. High affinity for proteins was observed for Nb, Ta and Ti, but not for W, in agreement with the dissimilar biological half-lives of these elements in the body. The different ability of the metals to interact with biochemical components and to be solubilized in biological media may explain the various degrees of retention in the lung, which would influence the metabolic pathways. This would explain the presence of Co, Ta and W in body fluids, as well as in the public hair and toenails of hard metal workers.

Dust↗
PubMed1994

The differential diagnosis of hard metal lung disease.

Hard metal lung disease is usually easy to diagnose, on the basis of occupational history, chest X-ray appearance of interstitial lung disease and, if necessary, by bronchoalveolar lavage (BAL). However, other interstitial lung diseases may affect patients with an occupational history of exposure to cobalt. In hard metal disease, the hylar lymphnodes may enlarge due to high draining of hard metals from the lung tissue via lymphatic vessels. Also, the presence of Giant Cells (even if Langhan's type) in the BAL fluid of sarcoid patients may be high. We present four patients with a history of exposure to hard metals and whose chest X-rays suggest sarcoidosis, stage II; in each, a pulmonary biopsy was necessary to confirm the diagnosis. Final diagnosis was sarcoidosis in one (showing typical granulomata in the lung tissue), and hard metal disease in three: two of these had foreign body-type granulomata in the lung tissue. Neutron activation analysis (NAA) study was carried out on these four patients using specimens of BAL fluid, blood, urine, toenails, pubic hair and sperm. In the light of available data, the concentration of elements may not be useful in differentiating between sarcoidosis and hard metal pneumoconiosis. However, NAA on BAL fluid or other specimens may be helpful in confirming the presence of the offending agent in suspected cases when the occupational history is not clear.

Adult↗
PubMed1996

Hard alpha-keratin intermediate filaments: an alternative interpretation of the low-angle equatorial X-ray diffraction pattern, and the axial disposition of putative disulphide bonds in the intra- and inter-protofilamentous networks.

STEM and electron microscopy have indicated that intermediate filaments (IF) may contain protofilaments and protofibrils, possibly with four and eight chains in section, respectively. Two important questions related to this observation but pertaining specifically to the structure of the hard alpha-keratin IF have been addressed in this work. The first relates to the apparently smaller number of chains in section (and hence protofilaments and/or protofibrils) in hard alpha-keratin IF as compared to epidermal keratin, vimentin and neurofilament IF. From the low-angle equatorial X-ray diffraction patterns the observed maxima were interpreted by others as arising from the Fourier transform of a uniformly dense cylinder of diameter 7.45 nm and, by implication, containing about 23 chains in section. Here it is shown that a simple, alternative density distribution for the IF is compatible with both the positions of the observed equatorial diffraction maxima and with 32 chains in section, thus allowing the possibility that IF from diverse sources (hard alpha-keratin, epidermal keratin, vimentin and neurofilaments) have a common number of chains in section and hence the same number of subfilamentous elements. The second point relates to the stabilisation of the protofilaments and/or protofibrils. It has been shown that the relative axial alignment of molecules in hard alpha-keratin IF is similar but not identical to that in both epidermal keratin and vimentin IF. A key difference involves the presence of a small gap (about 1.3-1.4nm) between similarly directed molecules as distinct from the head-to-tail overlap between parallel molecules that appears to be a characteristic of all other IF, and which is believed to have a major role in stabilising these assemblies. In contrast, it was proposed that the hard alpha-keratin IF gains its stability in part through a net work of intermolecular disulphide bonds. Here it is shown that disulphide bonds may exist between spatially-adjacent molecules one, two, three or four apart (and beyond) in the proposed surface lattice structure. This indicates the possibility that subfibrillar structural elements consisting of discrete groupings of disulphide-bonded molecules may be present in hard alpha-keratin IF.

Intermediate Filaments↗
PubMed2006

Erectile function and assessments of erection hardness correlate positively with measures of emotional well-being, sexual satisfaction, and treatment satisfaction in men with erectile dysfunction treated with sildenafil citrate (Viagra).

We aimed to determine whether erectile function (EF) and assessments of erection hardness correlate positively with measures of psychosocial outcomes (ie, emotional well-being, sexual satisfaction, and satisfaction with erectile dysfunction [ED] treatment) in men treated with sildenafil citrate (Viagra; Pfizer Inc, New York, NY). Data were collected from 33 worldwide phase 2, 3, and 4 sildenafil clinical trials, which included almost 10,000 men with ED. Most of these trials were randomized, double-blind, and placebo-controlled (n = 27) and were undertaken to assess doses of 50 mg adjustable to 25 mg or 100 mg, depending on efficacy and tolerability (n = 32). Doses were taken approximately 1 hour before anticipated sexual activity but not more often than once daily. EF was assessed with use of the EF domain of the International Index of Erectile Function (IIEF) and with assessments of erection hardness (Erection Hardness Grading Scale [EHGS] and IIEF Q2 [the frequency of erections hard enough for penetration]). Change (baseline to end point) in emotional well-being in men treated for ED was assessed with the Self-Esteem and Relationship (SEAR) questionnaire, which consisted of the Confidence domain (ie, the Self-Esteem subscale and Overall Relationship subscale) and the Sexual Relationship domain. End point treatment satisfaction (overall, speed of onset, and duration of action) was assessed with the Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS). The IIEF was used to assess change and end point sexual satisfaction by means of the Intercourse Satisfaction domain, Q7 (frequency of satisfactory sexual intercourse), and the Overall Satisfaction domain (ie, Q13, satisfaction with sex life, and Q14, satisfaction with sexual relationship). In men treated with sildenafil for ED, scores for measures of EF (IIEF EF domain, IIEF Q2) and the percentage of erections graded completely hard and fully rigid (EHGS grade 4) correlated positively with scores for measures of psychosocial outcomes (SEAR emotional well-being, IIEF sexual satisfaction, and EDITS ED treatment satisfaction), indicating that when EF improved and erection hardness increased, these measures of psychosocial function also improved.

Clinical Trials as Topic↗