Temporal-Focusing Multiphoton Excitation Single-Molecule Localization Microscopy Using Spontaneously Blinking Fluorophores

Single-molecule localization microscopy (SMLM) based on temporal-focusing multiphoton excitation (TFMPE) and single-wavelength excitation is used to visualize the three-dimensional (3D) distribution of spontaneously blinking fluorophore-labeled subcellular structures in a thick specimen with a nanoscale-level spatial resolution. To eliminate the photobleaching effect of unlocalized molecules in out-of-focus regions for improving the utilization rate of the photon budget in 3D SMLM imaging, SMLM with single-wavelength TFMPE achieves wide-field and axially confined two-photon excitation (TPE) of spontaneously blinking fluorophores. TPE spectral measurement of blinking fluorophores is then conducted through TFMPE imaging at a tunable excitation wavelength, yielding the optimal TPE wavelength for increasing the number of detected photons from a single blinking event during SMLM. Subsequently, the TPE fluorescence of blinking fluorophores is recorded to obtain a two-dimensional TFMPE-SMLM image of the microtubules in cancer cells with a localization precision of 18±6 nm and an overall imaging resolution of approximately 51 nm, which is estimated based on the contribution of Nyquist resolution and localization precision. Combined with astigmatic imaging, the system is capable of 3D TFMPE-SMLM imaging of brain tissue section of a 5XFAD transgenic mouse with the pathological features of Alzheimer's disease, revealing the distribution of neurotoxic amyloid-beta peptide deposits.

[Transcriptomic analysis of the ΔPaLoc mutant of Clostridioides difficile and verification of its toxicity]

Objective: Comparative analyses of wild-type Clostridioides difficile 630 (Cd630) strain and pathogenicity locus (PaLoc) knockout mutant (ΔPaLoc) by using RNA-seq technology. Analysis of differential expression of Cd630 wild-type strain and ΔPaLoc mutant strain and measurement of its cellular virulence changes. Lay the foundation for the construction of an toxin-attenuated vaccine strain against Clostridioides difficile. Methods: Analysis of Cd630 and ΔPaLoc mutant strains using high-throughput sequencing (RNA-seq). Clustering differentially expressed genes and screening differentially expressed genes by DESeq software. Further analysis of differential genes using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. Finally, cytotoxicity assays of ΔPaLoc and Cd630 strains were performed in the African monkey kidney epithelial cell (Vero) and the human colonic cell (Caco-2) lines. Results: The transcriptome data showed that the ΔPaLoc mutant toxin genes tcdA and tcdB were not transcribed. Compared to the wild-type strain, CD630_36010, CD630_020910,CD630_02080 and cel genes upregulated 17.92,11.40,8.93 and 7.55 fold, respectively. Whereas the hom2 (high serine dehydrogenase), the CD630_15810 (spore-forming protein), CD630_23230 (zinc-binding dehydrogenase) and CD630_23240 (galactitol 1-phosphate 5-dehydrogenase) genes were down-regulated by 0.06, 0.075, 0.133 and 0.183 fold, respectively. The GO and KEGG enrichment analyses showed that the differentially transcribed genes in ΔPaLoc were enriched in the density-sensing system, ABC transport system, two-component system, phosphotransferase (PTS) system, and sugar metabolism pathway, as well as vancomycin resistance-related pathways. Cytotoxicity assays showed that the ΔPaLoc mutant strain lost its virulence to Vero and Caco-2 cells compared to the wild-type Cd630 strain. Conclusion: Transcriptional sequencing analysis of the Cd630 and ΔPaLoc mutant strains showed that the toxin genes were not transcribed. Those other differential genes could provide a reference for further studies on the physiological and biochemical properties of the ΔPaLoc mutant strain. Cytotoxicity assays confirmed that the ΔPaLoc mutant lost virulence to Vero and Caco-2 cells, thus laying the foundation for constructing an toxin-attenuated vaccine strain against C. difficile.

Molecular determinants of U-type inactivation in Kv2.1 channels

Kv2.1 channels exhibit a U-shaped voltage-dependence of inactivation that is thought to represent preferential inactivation from preopen closed states. However, the molecular mechanisms underlying so-called U-type inactivation are unknown. We have performed a cysteine scan of the S3-S4 and S5-P-loop linkers and found sites that are important for U-type inactivation. In the S5-P-loop linker, U-type inactivation was preserved in all mutant channels except E352C. This mutation, but not E352Q, abolished closed-state inactivation while preserving open-state inactivation, resulting in a loss of the U-shaped voltage profile. The reducing agent DTT, as well as the C232V mutation in S2, restored U-type inactivation to the E352C mutant, which suggests that residues 352C and C232 may interact to prevent U-type inactivation. The R289C mutation, in the S3-S4 linker, also reduced U-type inactivation. In this case, DTT had little effect but application of MTSET restored wild-type-like U-type inactivation behavior, suggestive of the importance of charge at this site. Kinetic modeling suggests that the E352C and R289C inactivation phenotypes largely resulted from reductions in the rate constants for transitions from closed to inactivated states. The data indicate that specific residues within the S3-S4 and S5-P-loop linkers may play important roles in Kv2.1 U-type inactivation.

Molecular diversity of bacteria in Yunnan yellow cattle (Bos taurs) from Nujiang region, China

The rumen content of four Yunnan Yellow Cattle (Bos taurs) were collected to determine the bacteria diversity by using 16S rRNA gene sequence analysis. A total of 129 sequences were examined and the sequences were referred as 107 OTU (Operational Taxonomy Unit) according to the similarity level of 97% in gene sequence. Similarity analysis revealed that Yunnan Yellow Cattle had 12 sequences (10 OTU) shared 97% or greater similarity with cultured rumen bacteria Butyrivibrio fibrisolvens, Succiniclasticum ruminis, Ruminococcus bromii, Clostridium proteoclasticum, Ruminococcus flavefaciens, Pseudobutyrivibrio ruminis, Jeotgalicoccus psychrophilus, and Prevotella ruminicola, which accounting for 9.3% of the total clones (9.2% of the total OTU). The further 12 sequences (9 OTU) shared 90-97% similarity with cultured bacteria Clostridium aminobutyricum, butyrate-producing bacterium, Schwartzia succinivorans, Prevotella ruminicola, Eubacterium ruminantium, Ruminococcus albus, and Clostridium termitidis, also accounting for 9.3% of the total sequences (8.3% of the total OTU). The remaining 105 sequences (90 OTU) shared less than 90% similarity with cultured bacteria, accounting for 81.4% of the total sequences (82.5% of the total OTU). According to the phylogenetic analysis, all sequences were phylogenetically placed within phyla of low G+C subdivision (accounting for 72.1 and 72.5% of the total clones and OTU, respectively) and CFB subdivision (Cytophaga-Flexibacter-Bacteroides; accounting for 27.9 and 27.5% of the total clones and OTU, respectively). Among the examined clones, rare bacteria Jeotgalicoccus psychrophilus was detected in the rumen of cattle.

Risk and protective factors in association with mental health problems among people living with HIV who were former plasma/blood donors in rural China

A random sample of 271 people living with HIV (PLWH) who were former plasma/blood donors and a convenience sample of 67 HIV negative villagers were anonymously interviewed. Compared with the non-PLWH, PLWH reported higher prevalence of symptoms of depression (adjusted OR = 2.53, p=0.001), anxiety (adjusted OR = 1.85, p=0.04), and stress (adjusted OR = 1.77, p=0.06). Of the PLWH respondents, 81.7% received Highly Active Antiretroviral Therapy (HAART); 32.1% of whom reported some side effects. Respectively 13.7%, 37.4%, and 38.4% PLWH perceived discrimination from their family members, relatives/friends, and neighbors. Absence of HAART, poor physical function, perceived discrimination from relatives and friends, and low level of resilience were associated with depression (stepwise regression; beta = - 0.28-0.17, R-square = 0.22), anxiety and stress (R-square = 0.32 and 0.16, respectively). The majority of respondents (70.1%) desired group intervention as a means for providing psychological support services. Relevant programs should both remove risk factors (e.g., absence of medical treatment, HIV-related discrimination) and promote protective factors (e.g., resilience). Support group is one of the potentially useful approaches to provide psychological support services.

Potential contribution of a voltage-activated proton conductance to acid extrusion from rat hippocampal neurons

We examined the potential contribution of a voltage-gated proton conductance (gH+) to acid extrusion from cultured postnatal rat hippocampal neurons. In neurons loaded with Ca2+- and/or pH-sensitive fluorophores, transient exposures to 25-139.5 mM external K+ (K+o) or 20 microM veratridine in the presence of 2 mM Ca2+o (extracellular pH (pHo) constant at 7.35) caused reversible increases and decreases in intracellular free calcium concentration ([Ca2+]i) and intracellular pH (pHi), respectively. In contrast, under external Ca2+-free conditions, the same stimuli failed to affect [Ca2+]i but caused an increase in pHi, the magnitude of which was related to the [K+]o applied and the change in membrane potential. Consistent with the properties of gH+s in other cell types, the magnitude of the rise in pHi observed in the absence of external Ca2+ was not affected by the removal of external Na+ but was sensitive to external Zn2+ and temperature and was dependent on the measured transmembrane pH gradient (DeltapHmemb). Increasing DeltapH(memb) by pretreatment with carbonylcyanide-p-trifluoromethoxyphenylhydrazone augmented both the high-[K+]o-evoked rise in pHi and the Zn2+-sensitive component of the rise in pHi, suggestive of increased acid extrusion via a gH+. The inhibitory effect of Zn2+ at a given DeltapHmemb was further enhanced by increasing pHo from 7.35-7.8, consistent with a pHo-dependent inhibition of the putative gH+ by Zn2+. Under conditions designed to isolate H+ currents, a voltage-dependent outward current was recorded from whole-cell patch-clamped neurons. Although the outward current appeared to show some selectivity for protons, it was not sensitive to Zn2+ or temperature and the H+-selective component could not be separated from a larger conductance of unknown selectivity. Nonetheless, taken together, the results suggest that a Zn2+-sensitive proton conductive pathway is present in rat hippocampal neurons and contributes to H+ efflux under depolarizing conditions.

Angle analysis of Haglund syndrome and its relationship with osseous variations and Achilles tendon calcification

BACKGROUND

Haglund syndrome is a cause of posterior heel pain. The prominent posterosuperior projection into the retrocalcaneal bursa is thought to be a major etiology. Many methods have been proposed to measure the posterosuperior projection of the tuberosity into this bursa. The Fowler angle and the parallel pitch lines are the most frequently used. However, the relation between symptomatic Haglund syndrome and the measuring methods, especially the Fowler angle and parallel pitch lines, is not clear. The purposes of this paper were to study the predictive value of the most frequently used measurement methods to evaluate bursal impingement and to determine if other osseous variations and Achilles tendon calcification are associated with the development of Haglund syndrome.

METHODS

From October, 1996, to March, 2003, we evaluated 37 heels in 31 patients with symptomatic Haglund syndrome, and 40 heels in 27 individuals without posterior heel pain. On a lateral view radiograph, the Fowler angle, and the parallel pitch lines were measured, in addition to Achilles tendon calcification and the osseous variations, such as a posterior calcaneal step spur or plantar osseous projection.

RESULTS

The average Fowler angles in the control group and study group were 62.31 +/- 7.79 degrees and 60.14 +/- 7.01 degrees, respectively. There was no statistically significant difference (p = 0.490). The positive parallel pitch lines in the symptomatic group were 56.8% and in the control group 42.5%. There was no statistically significant difference (p = 0.474) between the groups.

CONCLUSIONS

No statistically significant differences were noted between the groups concerning the Fowler angle and parallel pitch lines. The posterior calcaneal step spur and Achilles tendon calcification were statistically significant between these two groups. The Fowler angle and parallel pitch lines were of little predictive value for the Haglund syndrome.

Prolonged interferon treatment after combination interferon and ribavirin therapy in patients with chronic hepatitis C: a clinical trial of interferon relapsers and non-responders

BACKGROUND AND PURPOSE

For the retreatment of chronic hepatitis C patients relapsing after, or non-responsive to, previous interferon therapy, the efficacy of combination therapy with interferon alfa plus ribavirin is superior to interferon alone. The aim of this study was to determine whether prolonged interferon alfa treatment after 24-week combination therapy can further increase the efficacy of combination therapy.

METHODS

Nineteen interferon relapsers and 17 interferon non-responders were randomly assigned to receive either interferon alfa 5 million units (MU) thrice weekly plus oral ribavirin 1,200 mg daily for 24 weeks (regimen A) or interferon alfa 5 MU thrice weekly plus oral ribavirin 1,200 mg daily for 24 weeks followed by interferon alfa 3 MU thrice weekly for another 24 weeks (regimen B). Efficacy was assessed by normalization of serum aminotransferase concentrations and disappearance of serum hepatitis C virus (HCV) RNA at the end of treatment and at 24 weeks after stopping treatment.

RESULTS

Overall, 67% of relapsers receiving regimen A and 80% of those receiving regimen B had sustained virologic responses 24 weeks after stopping treatment. In contrast, 45% of non-responders receiving regimen A and 63% of those receiving regimen B had sustained responses. The sustained response was more common in relapsers with non-1b HCV genotypes. The sustained response rate to combination therapy was 50% or more in patients with genotype 1b infection.

CONCLUSIONS

Prolonged interferon treatment after combination therapy has a comparable efficacy to combination therapy alone for the retreatment of chronic hepatitis C patients relapsing after, or non-responsive to, previous interferon therapy.

Surgical treatment for Haglund's deformity

Haglund's deformity, or "pump bump" is a common cause of posterior heel pain, characterized clinically by a painful soft tissue swelling at the level of the Achilles tendon insertion. We reviewed 30 heels in 19 patients with failure of conservative treatment. Surgical management consisted of excision of the posterior calcaneal tuberosity and bursectomy through a medial longitudinal incision. The average follow-up period was 6 years (range, 3-10 years). Only 3 heels (10%) in 2 patients had persistent pain. Twenty-seven heels (90%) were cured after operation. However, 25 heels (83%) had residual pain for a half to two years after operation and became free of symptoms thereafter. We conclude surgical treatment of Haglund's deformity produces a predictably good result (90%) but requires a long time about a half to two years for full recovery.

Isolated talonavicular arthrodesis for talonavicular arthritis

We have reviewed a single surgeon's experience with isolated talonavicular fusion in 16 patients with talonavicular arthritis. Fixation was either by staples or screws. Fifteen solid unions were achieved in the 16 patients who were followed (mean: 51 months). The average Ankle-Hindfoot Scale improved from 77.2 preoperatively to 92.9 postoperatively (p < 0.001). Subjectively, 15 patients were satisfied and one patient dissatisfied with the results. Further osteoarthritis in the adjacent joints was noted in five patients. We concluded that isolated talonavicular fusion is an effective method of treatment of talonavicular arthritis regarding pain relief and functional improvement. Though osteoarthritis was found in some adjacent joints postoperatively, the results were still satisfactory.

Low tibial osteotomy for moderate ankle arthritis

Low tibial osteotomy is one of the significant advances of ankle reconstruction techniques that has been made recently in an effort to halt arthritis in its early stages and leave fusion as the last, not the only, alternative treatment of ankle arthritis. From 1989 to 1995, we performed 18 low tibial osteotomies which included 6 cases of post-traumatic arthritis and 12 cases of degenerative arthritis. The ages of the 7 male and 11 female patients ranged from 18 to 78 years with an average of 41.9 years. The follow-up period lasted a mean of 47.7 months, ranging from 25 to 82 months. The average functional score changed from 49.6 pre-operatively to 88.5 at the last follow up, and showed yearly improvement. Complications included one case of late infection and two cases of implant failure, none of which led to nonunion. The indication for low tibial osteotomy is the intermediate stage of moderate ankle arthritis with a medial joint lesion and intact lateral facet. Using pressure redistribution on the joint surface, this procedure is an alternative treatment for ankle arthritis which may save an arthritic ankle from the fate of fusion or at least postpone fusion surgery.

Surgical treatment for concomitant fractures of the femoral neck and diaphysis: a treatment protocol

Concomitant ipsilateral femoral shaft and neck fractures are difficult to treat. The standard protocol in our hospital is plates for diaphyseal fractures and lag screws or dynamic hip screws (DHS) fixations for the femoral neck fractures. We treated 21 patients with these complex fractures between 1988 and 1998 with this protocol. All patients were injured from high-energy trauma. There were 15 males and 6 females with an average age of 44 years. The average follow-up period is 50 months. All except one patient united well. During the follow-up period, neither non-union of the femoral neck fracture nor osteonecrosis of the femoral head was noted. There was also no malunion. There were twenty good results and one poor functional result. We conclude that plate on the shaft and sliding hip screws or separate screws in the hip are a reliable method for concomitant ipsilateral femoral neck and shaft fractures.

Oestrogen deficiency causes DNA damage in uterine leiomyoma cells: a possible mechanism for shrinkage of fibroids by GnRH agonists

OBJECTIVE

To examine whether gonadotrophin-releasing hormone agonist or oestradiol can directly affect DNA in leiomyoma cells.

DESIGN

In vitro explant culture of leiomyoma cells.

SETTING

University research group.

SAMPLE

Leiomyoma cells were cultured from the specimens of four premenopausal women at myomectomy.

METHODS

The presence of gonadotrophin-releasing hormone receptor in leiomyoma cells was determined by reverse transcriptase-olymerase chain reaction. Leiomyoma cells were treated with gonadotrophin-releasing hormone agonist or cultured in different concentrations of oestrogen, progesterone or fetal calf serum for one, four or seven days.

MAIN OUTCOME MEASURES

Cell number, expression of proliferating cell nuclear antigen, and DNA damage after one, four or seven days of treatment.

RESULTS

Gonadotrophin-releasing hormone receptor messenger ribonucleic acid was detected on cultured leiomyoma cells. Leiomyoma cell growth was not affected by the addition of gonadotrophin-releasing hormone agonist or progesterone, but increased with oestrogen or fetal calf serum supplementation. Overexpression of proliferating cell nuclear antigen was prevented in cultures added with oestrogen or fetal calf serum, but not related to gonadotrophin-releasing hormone agonist treatment. Significant decreases in DNA damage as indicated by decreased comet number were found in the leiomyoma cultures treated with oestrogen or fetal calf serum for four and seven days but not with gonadotrophin-releasing hormone agonist or progesterone. Furthermore, 5% fetal calf serum supplementation was more growth supporting and more significantly reduced the comet number than 250 pM 17 beta-oestradiol.

CONCLUSION

Cell growth, proliferating cell nuclear antigen expression and DNA damage are dependent on oestrogen or fetal calf serum, but independent of gonadotrophin-releasing hormone agonist or progesterone. Our findings suggest that gonadotrophin-releasing hormone agonist-induced leiomyoma shrinkage may be due in part to a mechanism involving DNA damage, and support the hypothesis that gonadotrophin-releasing hormone agonist exerts its action indirectly through oestrogen action on the tumour level.

Potential of the genetic algorithm neural network in the assessment of gait patterns in ankle arthrodesis

The aim of this study was to develop an empirical model of parameter-based gait data, based on an artificial neural network and a genetic algorithm, for the assessment of patients after ankle arthrodesis. Ground reaction force vectors were measured by force platforms during level walking. Nine force parameters expressed in percentage of body weight and their chronologic incidence of occurrence expressed in percentage of stance phase period were used in modeling. Ten healthy persons and ten patients who had solid arthrodesis of the ankle were recruited in this study for developing the model. By applying the genetic algorithm neural network, the percentage of correct classification was 98.8% and the subset of discriminant parameters was be reduced to 9 out of 18. These key parameters were mainly related to the loading response and propulsive phase. This indicates that there was a reduction in the abilities in cushion impact and push off in the patients after ankle arthrodesis. Finally, the relative distance (Dr) was defined in this study and used in two new patients' examinations to demonstrate its clinical utility.

Ipsilateral fractures of the femoral neck and shaft

Ipsilateral femoral shaft and neck fractures are difficult to treat. From 1989 to 1998, we treated 18 patients with these complex fractures. There were 14 male and 4 female with an average age of 40 years. Most resulted from high-energy trauma. The average follow-up period is 41 months. All but one of the fractures united well. The mean time to union is 5.2+/-2.3 months in the diaphysis and 4.16+/-2 months in the neck. No cases of the femoral neck fracture or osteonecrosis of the femoral head were observed during the follow-up period. Fourteen cases were treated with a standard protocol of plates for diaphyseal fractures and lag screws or dynamic hip screws (DHS) fixations for the femoral neck fractures. There were 13 good and 1 fair functional results. Two neglected neck fractures were treated with interlocking nailing for diaphyseal fracture with fair results. We conclude that a plate on the shaft and sliding hip screws or separate screws in the hip is a reliable method for ipsilateral femoral neck and shaft fractures.

Large-scale mitochondrial DNA deletions in skeletal muscle of patients with end-stage renal disease

End-stage renal disease (ESRD) is associated with enhanced oxidative stress. This disease state provides a unique system for investigating the deleterious effect of exogenous sources of free radicals and reactive oxygen species (ROS) on mitochondrial DNA (mtDNA). To test the hypothesis that uremic milieu might cause more severe damage to mtDNA, we investigated the prevalence and abundance of mtDNA deletions in the skeletal muscles of ESRD patients. The results showed that the frequencies of occurrence of the 4977 bp and 7436 bp deletions of mtDNA in the muscle tissues of the older ESRD patients were higher than those of the younger patients. The frequency of occurrence of the 4977 bp-deleted mtDNA in the muscle was 33.3% for the patients in the age group of < 40 years, 66.6% in the 41-60-year-old group, 100% in the 61-80-year-old group, and 100% in patients >80 years of age, respectively. Only 22% of the normal aged controls carried the 4977 bp mtDNA deletion, whereas 77% (17/22) of the ESRD patients exhibited the mtDNA deletion. Using a semiquantitative PCR method, we determined the proportion of the 4977 bp-deleted mtDNA from the muscles that had been confirmed to harbor the deletion. We found that the proportions of the 4977 bp-deleted mtDNA in the muscle were significantly higher than those of the aged matched controls. Using long-range PCR techniques, a distinctive array of mtDNA deletions was demonstrated in the muscle of uremic patients. In summary, we found diverse and multiple mtDNA deletions in the skeletal muscles of ESRD patients. These deletions are more prevalent and abundant in ESRD patients than those found in normal populations. Accumulation of uremic toxins and impaired free radical scavenging systems may be responsible for the increased oxidative stress in ESRD patients. Such stress may result in oxidative damage and aging-associated mutation of the mitochondrial genome.

Color Doppler vascularity index can predict distant metastasis and survival in colon cancer patients

The purpose of this study was to investigate the clinical usefulness of the color Doppler vascularity index (CDVI) in patients with colon cancer before surgery. Forty-four patients with sonographically visible tumor mass of colon cancer were investigated. The CDVI of each tumor was determined using transabdominal color Doppler ultrasound. The CDVI was defined as the ratio of the number of the colored pixels within a tumor section to the number of total pixels in that specific tumor section and was calculated by using Encomate software (Electronic Business Machine Co. Ltd., Taipei, Taiwan). The correlation between the CDVI and clinicopathological factors, mode of recurrence, and patient survival was studied. For comparison, microvessel density (the mean number of microvessels in three areas of highest vascular density at x200 magnification) of the tumors of these 44 patients was also evaluated by using immunohistochemical staining of surgical specimens with anti-CD34. The microvessel density was not correlated with Dukes' classification, clinicopathological factors, and survival. The CDVI was significantly higher in the patients with lymph node metastases and vascular invasion than in those without such metastases and invasion (P = 0.006 and P = 0.0098, respectively). Moreover, in patients with a high CDVI (> 15%) and positive vascular invasion, survival was significantly poorer than in those with low CDVI (< or = 15%) and negative invasion (P = 0.0037 and 0.0039, respectively). Multivariate analysis indicated that liver metastasis, vascular invasion, and CDVI are independent prognostic factors in the patients with colon cancer. According to the mode of recurrence in 36 patients who underwent curative resection, the frequency of the distant organ recurrence was significantly higher in the high CDVI group (40%) than in the low CDVI group (0%). The CDVI is a good preoperative indicator of recurrence and patient survival in colon cancer. Thus, the CDVI may be helpful in stratifying patients for adjuvant therapy.

Open total talar dislocation--report of two cases

Total dislocation of talus from all its surrounding joints (tibiotalar, subtalar and talonavicular) is an extremely rare injury. Because of its rarity, only few case reports can be found in the literature. In the review of the literature, infection and AVN are the most commonly encountered complications that affect the outcome of these severe injuries. Herein we report two cases of open total talar dislocation. Immediate debridement, reduction of the talus, and primary skin closure was done followed by cast immobilization. After more than 2 years follow up, neither infection nor AVN was found. We conclude that reimplantation of the talus is preferable if the wound is relatively clean. Talectomy, or combined with tibiocalcaneal fusion should be reserved for later salvage procedure.

Postero-medio-anterior approach of the ankle for the pilon fracture

A good view of the operative field is important for better reduction and fixation in surgical treatment of fractures. The exposure of the ankle joint for the pilon fracture is commonly through the anterior approach, or combined with the medical approach. But sometimes it is still difficult to have complete viewing of the articular surface and to apply internal fixation by that approach. In recent years, we developed a "postero-medio-anterior" approach of the ankle joint by one incision. This approach provides an excellent exposure of the anterior, medial and posterior aspects of the ankle joint with a clear view of the articular surface. In our 45 cases of pilon fracture during 1991 to 1995, there was no incisional injury to the neurovascular bundle. Superficial wound edge necrosis was noted in two cases which healed later without further procedure. Therefore, we recommend this approach as a simple and reliable incision for open reduction of pilon fractures.

The surgical treatment for degenerative disease of the ankle

Although a variety of surgical techniques are available for the surgical treatment of early degenerative disease of the ankle, arthrodesis remains the preferred treatment for severe cases. We studied 126 ankles with an average follow up of 39 months of whom 25 with early disease underwent debridement and cheilectomy, 18 with intermediate disease underwent lower tibial osteotomy and 83 with severe disease underwent either arthrodesis (78) or total ankle replacement (5). In 96% of cases there was a satisfactory functional outcome.

Dynamics of dental implants and orthodontics in today's periodontal prosthesis

Periodontal prosthesis refers to multidisciplinary efforts to stop disease progression, correct deformities created by dental diseases, and establish a therapeutic occlusion to restore the form and function of the masticatory system. These efforts are critical for the long-term prognosis and maintenance of the guarded teeth and the overall prosthesis. This article presents a functionally and esthetically challenging case, which illustrates a multidisciplinary approach--specifically implantology and orthodontics--and how they impact on each other during treatment. The role and importance of dental implants and orthodontics in setting up a case is illustrated in this article.