Prominence of scientific publications towards peri-implant complications in implantology: A bibliometric analysis using the H-classics method.

Current bibliometric analyses of the evolving trends in research scope category across different time periods using the H-classics method in implantology are considerably limited. The purpose of this study was to identify the classic articles in implantology to analyse bibliometric characteristics and associated factors in implantology for the past four decades. H-Classics in implantology were identified within four time periods between 1977 and 2016, based on the h-index from the Scopus® database. For each article, the principal bibliometric parameters of authorship, geographic origin, country origin, and institute origin, collaboration, centralisation, article type, scope of study and other associated factors were analysed in four time periods. A significant increase in mean numbers of authors per H-Classics was found across time. Both Europe and North America were the most productive region/country and steadily dominated this field in each time period. Collaborations of author, internationally and inter-institutionally had significantly increased across time. A significant decentralisation in authorships, institutes and journals was noted in past four decades. The journal of Clinical Oral Implant Researches has raised its importance for almost 30 years (1987-2016). Research on Complications, peri-implant infection/pathology/therapy had been increasing in production throughout each period. This is the first study to evaluate research trends in implantology in the past 40 years using the H-classics method, which through analysing via principle bibliometric characteristics reflected a historical perspective on evolutionary mainstream in the field. Prominence of research regarding complications may forecast innovative advancements in future.

Restoration of erectile function with intracavernous injections of endothelial progenitor cells after bilateral cavernous nerve injury in rats.

Endothelial progenitor cells (EPCs) are bone marrow-derived endothelial cells capable of circulating, proliferating, and differentiating into mature endothelial cells. Circulating EPCs can be directly recruited to some extent at sites of injury, and their administration could accelerate repair or endothelialization of the damaged tissue. We investigated the effects of intracavernous injections of EPCs into the corpora cavernosa of rats with erectile dysfunction (ED) caused by bilateral cavernous nerve (CN) injury. Overall, 24 male Sprague-Dawley rats were randomized into three groups: sham surgery, vehicle-only, or EPC treatment. Rats in the EPC treatment and vehicle-only groups were subjected to bilateral CN injury before injection of EPCs or vehicle, respectively, into the corpora cavernosa. Four weeks after surgery, erectile function was assessed by measuring maximum intracavernosal pressure (ICP), change in ICP, area under the ICP curve, and ratio of change in ICP and mean arterial pressure (MAP; ΔICP/MAP). Penile tissue was histomorphometrically analyzed for the expression of neural nitric oxide synthase (nNOS), neurofilament-1 (NF-1), von Willebrand factor (vWF), endothelial NOS (eNOS), and smooth muscle cell content. Maximum ICP and all other functional parameters of erectile function were significantly reduced in the vehicle-only group vs. the sham and EPC treatment groups (all p < 0.001). Smooth muscle cell content was decreased in the vehicle-only vs. the sham and EPC treatment groups (both p < 0.01). Expressions of vWF and eNOS in the dorsal artery were significantly higher in the EPC treatment than the vehicle-only group (p < 0.05). In conclusion, EPC treatment restored erectile function in a rat model of bilateral CN injury through recruitment of EPCs toward the dorsal artery and preservation of smooth muscle cells in the corpus cavernosum. These findings elucidate the therapeutic potential of EPCs for treating ED in humans.

Testosterone replacement therapy can increase circulating endothelial progenitor cell number in men with late onset hypogonadism.

Circulating endothelial progenitor cells (EPCs) are bone marrow-derived cells required for endothelial repair. A low EPC number can be considered as an independent predictor of endothelial dysfunction and future cardiovascular events. Recent evidence shows that patients with hypogonadal symptoms without other confounding risk factors have a low number of circulating progenitor cells (PCs) and EPCs, thus highlighting the role of testosterone in the proliferation and differentiation of EPCs. Here, we investigate if testosterone replacement therapy (TRT) can increase circulating EPC number in men with late onset hypogonadism. Forty-six men (age range, 40-73 years; mean age, 58.3 years) with hypogonadal symptoms were recruited, and 29 men with serum total testosterone (TT) levels less than 350 ng/dL received TRT using transdermal testosterone gel (Androgel; 1% testosterone at 5 g/day) for 12 months. Circulating EPC numbers (per 100 000 monocytes) were calculated using flow cytometry. There was no significant association between serum TT levels and the number of circulating EPCs before TRT. Compared with the number of mean circulating EPCs at baseline (9.5 ± 6.2), the number was significantly higher after 3 months (16.6 ± 11.1, p = 0.027), 6 months (20.3 ± 15.3, p = 0.006) and 12 months (27.2 ± 15.5, p = 0.017) of TRT. Thus, we conclude that serum TT levels before TRT are not significantly associated with the number of circulating EPCs in men with late onset hypogonadism. However, TRT can increase the number of circulating EPCs, which implies the benefit of TRT on endothelial function in hypogonadal men.

Association of metabolic syndrome, atherosclerosis risk factors, sex hormones in ED in aboriginal Taiwanese.

The overall prevalence of metabolic syndrome (MS) in aboriginal male Taiwanese is very high. Many studies have found that those with cardiovascular disease and MS have a significantly higher risk of ED. In this study, we attempted to find the correlation among MS risk factor, atherosclerosis risk factors and low serum testosterone in relation to the development of ED. This was a cross-sectional study of 238 cases, and collected data included demographic data, lifestyle questionnaires, sexual desire scale, sexual satisfaction scale and International Index of Erectile Function (IIEF) questionnaire. Among our 238 subjects, 146 had MS (61.3%) and 114 subjects with MS had ED (85.7%). Using age-adjusted multivariate logistic regressive analysis, this study showed that aboriginal males with ED had a significantly higher prevalence of MS (OR=12.02, 95% confidence intervals (CI): 6.33-22.83, P<0.001). Among the MS components, abnormal fasting blood sugar was the most significantly independent factor for ED in aboriginal males (OR=8.94, 95% CI: 4.71-16.97, P<0.001). The presence of MS had a significant correlation with lower IIEF-5 scores, lower sexual desire scores, lower testosterone serum level (P<0.01) and abnormal interleukin-6 (IL-6) and high sensitivity C-reactive protein (HsCRP). The results of this study support the idea that MS, low serum testosterone and HsCRP may predict ED in aboriginal Taiwanese males. Further studies with population-based and longitudinal design should be conducted to confirm this finding and design to compare rates of ED in aboriginal men with MS.

Nonlinear magnetoresistance oscillations in intensely irradiated two-dimensional electron systems induced by multiphoton processes.

We report on magneto-oscillations in differential resistivity of a two-dimensional electron system subject to intense microwave radiation. The period of these oscillations is determined not only by microwave frequency but also by its intensity. A theoretical model based on quantum kinetics at high microwave power captures all important characteristics of this phenomenon which is strongly nonlinear in microwave intensity. Our results demonstrate a crucial role of the multiphoton processes near the cyclotron resonance and its harmonics in the presence of strong dc electric field and offer a unique way to reliably determine the intensity of microwaves acting on electrons.

CFTR (TG)m(T)n polymorphism in patients with CBAVD in a population expressing low incidence of cystic fibrosis.

As it is well established that an association exists between congenital bilateral absence of the vas deferens (CBAVD) and cystic fibrosis gene mutations, we investigated CFTR(TG)m(T)n polymorphism within a Taiwanese population that exhibits a very low incidence of CF. Sixty-three patients with CBAVD and 86 age-matched normal control subjects were evaluated. Temporal temperature gradient gel electrophoresis was used for CFTR mutational analysis. No major CFTR mutation was found in the patient series. A single prominent CFTR mutation, IVS8-5T, was present; however, (50.8% of 63 cases and 33.3% of 126 alleles), and exhibited a high prevalence of 12 or 13 TG repeats (93.8% of 32 cases and 95.2% of 42 alleles with IVS8-5T). Although these results are similar to those of Japanese CBAVD patients, they are higher than the common frequency (about 21%) found among Caucasian CBAVD patients. The very high percentage (42.9%) of patients with no CFTR mutations is also an ethnic characteristic. We concluded that CBAVD patients from Taiwan, who express a very low incidence of CF, were less affected by CFTR mutations, with the exception of IVS8-5T linked to either 12 or 13 TG repeats, which does exhibit a high prevalence among CBAVD patients tested.

Microwave photoresistance in dc-driven 2D systems at cyclotron resonance subharmonics.

We study microwave photoresistivity oscillations in a high-mobility two-dimensional electron system subject to strong dc electric fields. We find that near the second subharmonic of the cyclotron resonance the frequency of the resistivity oscillations with a dc electric field is twice the frequency of the oscillations at the cyclotron resonance, its harmonics, or in the absence of microwave radiation. This observation is discussed in terms of the microwave-induced sidebands in the density of states and the interplay between different scattering processes in the separated Landau level regime.

Inhibitory effect of lycopene on PDGF-BB-induced signalling and migration in human dermal fibroblasts: a possible target for cancer.

Tumours are complex tissues composed of both matrix proteins and stromal cells such as fibroblasts and inflammatory cells. Tumour progression is often the result of dynamic interactions between the tumour cells and their surroundings. Lycopene, a natural carotenoid that is abundant in tomato, has been shown to inhibit proliferation of several types of cancer cells through arrest of tumour cell-cycle progression, IGF-1 (insulin-like growth factor 1) signalling transduction, induction of apoptosis etc. However, in our recent study, we found that lycopene inhibited PDGF-BB (platelet-derived growth factor-BB)-induced signalling and cell migration in human cultured skin fibroblasts through a novel mechanism of action, i.e. direct binding to PDGF-BB. Trapping of PDGF by lycopene also compromised melanoma-induced fibroblast migration and attenuated signalling transduction in fibroblasts simulated by melanoma-derived conditioned medium, suggesting that lycopene may interfere with tumour-stroma interactions. The trapping activity of lycopene on PDGF suggests that it may act as an inhibitor on stromal cells, tumour cells and their interactions, which may contribute to its anti-tumour activity.

Transdermal testosterone gel increases serum testosterone levels in hypogonadal men in Taiwan with improvements in sexual function.

A randomized, double-blind, placebo-controlled trial was conducted to (1) evaluate efficacy and safety of transdermal testosterone gel (AndroGel) for hypogonadal men in Taiwan, and (2) observe improvements in sexual function through international index of erectile function (IIEF) scores. Eligible hypogonadal men were randomized to receive 50 mg/day transdermal testosterone gel (TTG) or placebo for 3 months. Primary end point was change from baseline in total testosterone (TT) and free testosterone (FT). Secondary end points were change from baseline in serum hormone levels (such as dihydrotestosterone (DHT), estradiol (E2), luteinizing hormone (LH), follicle-stimulating hormone (FSH) and sex-hormone-binding globulin (SHBG)) and changes in IIEF scores. Safety evaluations included adverse events (AEs) and skin irritation assessment. Compared with baseline, the TTG group (n=20) had statistically significant increases in mean TT levels at month 1 (P=0.024) and month 2 (P=0.025), but no significant changes at month 3. TT levels in the placebo group (n=18) showed no statistically significant change at any visit. Changes in FT levels paralleled changes in TT levels in both groups. TTG group IIEF scores were significantly increased at month 3 (P=0.01), compared with a decline in placebo scores. No drug-related AEs occurred in the TTG group; the placebo group had 2 AEs (mild skin rash). In conclusion, TTG effectively restores serum TT and FT levels to a normal physiological range for hypogonadal men in Taiwan and improves sexual function.

Correlations of androgen deficiency with clinical symptoms in Taiwanese males.

The purpose of this study was to elucidate correlations between different biochemical measurements of androgen deficiency and clinical symptoms in male residents of Taiwan. An investigation of the serum biochemical markers for androgen deficiency in 650 males, including total testosterone, calculated free testosterone, and bioavailable testosterone, was conducted. Measurements of clinical symptoms were obtained using a questionnaire of the androgen deficiency in the aging male (ADAM) by St Louis University (SLQ). Correlations among the biochemical markers, correlations of the biochemical markers and age, and relationships between the biochemical markers and the SLQ were evaluated. The sensitivity and specificity of the SLQ were determined. Bioavailable and calculated free testosterone correlated better with age than did total testosterone. Eighty percent of the men had a positive SLQ, and 20% had a negative SLQ. The percentage of positive SLQ results increased with age. No statistically significant difference was noted between the biochemical markers of bioavailable and calculated free testosterone levels and the SLQ status except for men aged over 70 years. The SLQ in this study showed an acceptable sensitivity of about 80%, but the specificity was poor (about 20%). In conclusion, bioavailable testosterone and calculated free testosterone were more-closely correlated with age and may be better biochemical markers for androgen deficiency. SLQ might not be a suitable single measurement for androgen deficiency and should be used together with biochemical markers.

Prevalence of erectile dysfunction and impacts on sexual activity and self-reported intercourse satisfaction in men older than 40 years in Taiwan.

In order to assess the prevalence of erectile dysfunction (ED), and its association with chronic diseases and impact upon sexual activity and satisfaction during sexual intercourse, a reproductive survey was conducted among 1002 Taiwanese men aged over 40 y. The information collected comprised age, gender, level of education, history of chronic diseases, and self-reported data pertaining to erectile function, sexual activity, and sexual satisfaction during sexual intercourse. The prevalence of ED amongst study subjects was 17.7%, and the frequency increased with age. A history of chronic diseases were significantly associated with ED (P<0.05). A reduced incidence of sexual activity and a decreased level of satisfaction during sexual intercourse were observed among subjects suffering from ED as compared to those not suffering such a condition. In conclusion, based upon the results of a community-based survey the prevalence of ED among Taiwanese men aged 40 y or more was 17.7% and it increased with age. It was also found that ED was associated with various chronic diseases and that it exerted a negative impact upon sexual activity and the level of satisfaction associated with its conduct.

Cystic fibrosis transmembrane conductance regulator gene screening and clinical correlation in Taiwanese males with congenital bilateral absence of the vas deferens.

BACKGROUND: In Taiwan, an area with a very low incidence of cystic fibrosis (CF), we first screened for the most common mutations of the cystic fibrosis transmembrane conductance regulator (CFTR) gene and looked for clinical correlations in 27 patients with clinically diagnosed congenital bilateral absence of the vas deferens (CBAVD). METHODS AND RESULTS: The clinical results showed that none of the 27 patients had CF symptoms. We did not detect any definite renal anomaly ultrasonographically. Mutation analysis was carried out on these 27 cases and 46 normal fertile males as controls. No mutations of Delta F508 or R117H were identified in any of the samples analysed. In the screening of IVS8-poly T, five of the 27 CBAVD patients showed the homozygous genotype for 5T/5T, 14 showed the heterozygous genotype for 5T/7T and eight showed the homozygous genotype for 7T/7T. The frequency of 5T alleles was 44.4%, which was significantly higher than in the 46 normal fertile males, for which there was a 5T frequency of 5.4%. CONCLUSIONS: The absence of major mutations of CFTR genes could be related to the much lower CF incidence in Taiwan. Further investigations into differences in the mutation spectrum of other CFTR genes are needed for a better understanding of the development of Taiwanese-Oriental CBAVD.

Changing trends of prostate cancer in Asia.

Although Asian people have the lowest incidence and mortality rates of prostate cancer in the world, these rates have risen rapidly in the past two decades in most Asian countries. Prostate cancer has become one of the leading male cancers in some Asian countries. In 2000, the age-adjusted incidence was over 10 per 100000 men in Japan, Taiwan, Singapore, Malaysia, the Philippines and Israel. Although some of the increases may result from enhanced detection, much of the increased incidence may be associated with westernization of the lifestyle, with increasing obesity and increased consumption of fat. The differences in incidences between native Americans and Asian immigrants are getting smaller, reflecting a possible improvement of diagnostic efforts and changes of environmental risk factors in Asian immigrants. Nevertheless, the huge variations in incidences among ethnic groups imply that there are important genetic risk factors. The stage distributions of prostate cancer in Asian populations are still unfavorable compared to those of Western developed countries. However, a trend towards diagnosing cancer with more favorable prognosis is seen in most Asian countries. Both genetic and environmental risk factors responsible for elevated risks in Asian people are being identified, which may help to reduce prostate cancer incidence in a chemopreventive setting.

Genetic screening for patients with azoospermia and severe oligo-asthenospermia.

In order to explore the genetic defects of patients with azoospermia or severe oligo-asthenospermia, screening examinations were carried out for the chromosome disorder and gene deletion of the Y chromosome for 220 male infertility patients. The present results show that the total prevalence of genetic defects is 23.6%, including 38 patients (28.4%) with chromosome disorder and 14 patients (16.8%) with gene deletion in the Yq arm. The most prevalent chromosome anomaly is 47XXY (Klinefelter's syndrome), which includes 18 cases of pure type and three cases of mosaic type. Variable autosomal translocations occurred in both the azoospermia group (5.2%) and the oligo-astheno-spermia group (5.8%) with similar prevalence. A total of 22 patients had deletions of the variable, interstitial portion of the Yq arm. These gene deletions are distributed not only inside the AZF region, but also outside of this region. The severity of deletions is not well correlated to the clinical testicular function of the patients. We conclude that chromosome disorder and gene deletions are the causative factors of patients with azoospermia and oligo-asthenospermia. Genetic screening should be a routine examination for them before the use of assisted-reproductive technologies.

10 years of experience with penile prosthesis implantation in Taiwanese patients.

PURPOSE: We evaluated the long-term results of penile prosthesis implantation during the last 10 years. Special considerations were examined concerning Asian corporeal diameter, device survival and sociocultural factors influencing patient-partner satisfaction. MATERIALS AND METHODS: We followed 331 patients who underwent penile prosthesis implantation from December 1985 to May 1996. Surgical data, postoperative complications and information from a survey on satisfaction are reported. RESULTS: The most prevalent corporeal diameter in our patients was 11.0 to 11.5 cm. Postoperatively wound infection was the most serious surgical complication. The 5-year device survival was similar in the malleable and inflatable types except for a poorer outcome with the self-contained inflatable Hydroflex penile prosthesis. Overall patient satisfaction with surgery was 86.6%. CONCLUSIONS: Penile prosthesis implantation still has its place as definitive therapy in some patients with uncorrectable erectile dysfunction. In Taiwanese society more consideration of prosthesis selection, surgical preparation and patient-partner counseling is the basis for further success in the future.

Titration study of MUSE (Medicated Urethral System for Erection) in erectile dysfunction.

PURPOSE: We assessed the erectile responses and adverse reactions to prostaglandin E1 delivered via the medicated urethral system for erection (MUSE) in a titration study to determine optimal dose. METHODS: Sixty-four patients with erectile dysfunction underwent in-office testing with MUSE to determine erectile response. Following thorough instructions, patients were taught how to use MUSE themselves. The titration study started with a dose of 125 micrograms, and increased to 250 micrograms, 500 micrograms, and finally 1,000 micrograms. In patients who had an erectile response, erection scoring, color duplex Doppler study, blood pressure monitoring, recording of subjective complaints, and repeated laboratory examinations were performed to evaluate the positive and adverse effects of MUSE. RESULTS: Forty-three of the 64 patients achieved a maximal erection with MUSE, as shown by systolic peak flow velocities in the deep penile arteries of greater than 27 cm/s on Doppler ultrasonography. One patient was unsatisfied with his erectile response and dropped out of the study. Of the 42 patients who completed the study, most (35) were satisfied with the response achieved at the higher doses of 500 micrograms and 1,000 micrograms. A modified soft rubber band was needed to achieve a satisfactory erectile response in 18 patients. Only four patients experienced serious urethral burning during MUSE application. CONCLUSIONS: MUSE was effective and safe in most patients with erectile dysfunction in this study. For patients not satisfied with the extent of penile rigidity achieved with MUSE, the use of a modified soft rubber band for erectile assistance, as well as a program for improved patient education, may help to achieve a better erectile response and facilitate compliance with treatment regimens at home.

Complications of urinary diversion after pelvic exenteration for gynecological malignancy.

A series of 21 patients who underwent pelvic exenteration for local advanced or recurrent gynecological malignancies and urinary diversions was retrospectively reviewed. The major disease process was carcinoma of the cervix. Early complications included sepsis with wound infection and dehiscence in 4 patients, intestinal insuffency in 2 patients, 4 urinary fistulas and 3 ureteral obstructions. Six patients had a late urinary complication of stenosis of the ureterointestinal anastomosis; stones in the urinary reservoir and pyelonephritis were also noted. Factors responsible for these complications are identified and discussed with a view to reducing the morbidity related to urinary diversion in such patients.

The percutaneous penetration of prostaglandin E1 and its alkyl esters.

The percutaneous delivery of PGE1 and its alkyl esters in alcoholic saline solution through hairless mouse skin was compared. The quantification of alkyl esters was based on the same principle as that for PGE1, which was converted to PGB1 to enhance the sensitivity and minimize the interference. Results showed that it was PGE1 that appeared in the receiver compartment for all alkyl esters examined. The flux of all alkyl esters of PGE1 in the same concentration was higher than PGE1 itself at most of saline vehicle with various fractions of alcohol. The maximal flux for a fixed concentration of each alkyl ester appeared at different fractions of alcohol. When the fractions of alcohol was kept constant, the alkyl ester that showed the maximal flux at this concentration appeared to have a longer chain length with increasing the fraction of alcohol. But isopropyl ester deviated from this order. It was concluded that the alkyl ester derivatives promoted the penetration of PGE1 mainly as a result of enhancing the drug partitioning into the stratum corneum. The alcohol fraction that needed to achieve the maximal flux at the same concentration increased with the increase of alkyl chain length, which resulted in the decrease of solubility parameter. It is necessary to optimize the fraction of alcohol in the saline solution in order to achieve the maximal flux at a fixed concentration for these alkyl esters with different alkyl chain length.