Integrated Biofilm Modification and Transcriptional Analysis for Improving Fengycin Production in Bacillus amyloliquefaciens

Although fengycin exhibits broad-spectrum antifungal properties, its application is hindered due to its low biosynthesis level and the co-existence of iturin A and surfactin in Bacillus amyloliquefaciens HM618, a probiotic strain. In this study, transcriptome analysis and gene editing were used to explore the potential mechanisms regulating fengycin production in B. amyloliquefaciens. The fengycin level of B. amyloliquefacien HM-3 (∆itu-ΔsrfAA) was 88.41 mg/L after simultaneously inhibiting the biosyntheses of iturin A and surfactin. The knockout of gene eps associated with biofilm formation significantly increased the fengycin level of the strain HM618, whereas the fengycin level decreased 32.05% after knocking out sinI, a regulator of biofilm formation. Transcriptome analysis revealed that the differentially expressed genes, involved in pathways of amino acid and fatty acid syntheses, were significantly down-regulated in the recombinant strains, which is likely associated with a decrease of fengycin production. The knockout of gene comQXPA and subsequent transcriptome analysis revealed that the ComQXPA quorum sensing system played a positive regulatory role in fengycin production. Through targeted genetic modifications and fermentation optimization, the fengycin production of the engineered strain HM-12 (∆itu-ΔsrfAA-ΔyvbJ) in a 5-L fermenter reached 1.172 g/L, a 12.26-fold increase compared to the fengycin level in the strain HM-3 (∆itu-ΔsrfAA) in the Erlenmeyer flask. Taken together, these results reveal the underlying metabolic mechanisms associated with fengycin synthesis and provide a potential strategy for improving fengycin production in B. amyloliquefaciens.

Enhancement of polymyxin B1 production by an artificial microbial consortium of Paenibacillus polymyxa and recombinant Corynebacterium glutamicum producing precursor amino acids

Polymyxin B, produced by Paenibacillus polymyxa, is used as the last line of defense clinically. In this study, exogenous mixture of precursor amino acids increased the level and proportion of polymyxin B1 in the total of polymyxin B analogs of P. polymyxa CJX518-AC (PPAC) from 0.15 g/L and 61.8 % to 0.33 g/L and 79.9 %, respectively. The co-culture of strain PPAC and recombinant Corynebacterium glutamicum-leu01, which produces high levels of threonine, leucine, and isoleucine, increased polymyxin B1 production to 0.64 g/L. When strains PPAC and C. glu-leu01 simultaneously inoculated into an optimized medium with 20 g/L peptone, polymyxin B1 production was increased to 0.97 g/L. Furthermore, the polymyxin B1 production in the co-culture of strains PPAC and C. glu-leu01 increased to 2.21 g/L after optimized inoculation ratios and fermentation medium with 60 g/L peptone. This study provides a new strategy to improve polymyxin B1 production.

An Engineered Microbial Consortium Provides Precursors for Fengycin Production by Bacillus subtilis

Fengycin has great potential for applications in biological control because of its biosafety and degradability. In this study, the addition of exogenous precursors increased fengycin production by Bacillus subtilis. Corynebacterium glutamicum was engineered to produce high levels of precursors (Thr, Pro, Val, and Ile) to promote the biosynthesis of fengycin. Furthermore, recombinant C. glutamicum and Yarrowia lipolytica providing amino acid and fatty acid precursors were co-cultured to improve fengycin production by B. subtilis in a three-strain artificial consortium, in which fengycin production was 2100 mg·L-1. In addition, fengycin production by the consortium in a 5 L bioreactor reached 3290 mg·L-1. Fengycin had a significant antifungal effect on Rhizoctonia solani, which illustrates its potential as a food preservative. Taken together, this work provides a new strategy for improving fengycin production by a microbial consortium and metabolic engineering.

Enhancing fengycin production in the co-culture of Bacillus subtilis and Corynebacterium glutamicum by engineering proline transporter

Fengycin possesses antifungal activity but has limited application due to its low yields. Amino acid precursors play a crucial role in fengycin synthesis. Herein, the overexpression of alanine, isoleucine, and threonine transporter-related genes in Bacillus subtilis increased fengycin production by 34.06%, 46.66%, and 7.83%, respectively. Particularly, fengycin production in B. subtilis reached 871.86 mg/L with the addition of 8.0 g/L exogenous proline after enhancing the expression of the proline transport-related gene opuE. To overcome the metabolic burden caused by excessive enhancement of gene expression for supplying precursors, B. subtilis and Corynebacterium glutamicum which produced proline, were co-cultured, which further improved fengycin production. Fengycin production in the co-culture of B. subtilis and C. glutamicum in shake flasks reached 1554.74 mg/L after optimizing the inoculation time and ratio. The fengycin level in the fed-batch co-culture was 2309.96 mg/L in a 5.0-L bioreactor. These findings provide a new strategy for improving fengycin production.

Improved Production of Fengycin in Bacillus subtilis by Integrated Strain Engineering Strategy

Fengycin is a lipopeptide with broad-spectrum antifungal activity. However, its low yield limits its commercial application. Therefore, we iteratively edited multiple target genes associated with fengycin synthesis by combinatorial metabolic engineering. The ability of Bacillus subtilis 168 to manufacture lipopeptides was restored, and the fengycin titer was 1.81 mg/L. Fengycin production was further increased to 174.63 mg/L after knocking out pathways associated with surfactin and bacillaene synthesis and replacing the native promoter (P_ppsA) with the P_veg promoter. Subsequently, fengycin levels were elevated to 258.52 mg/L by upregulating the expression of relevant genes involved in the fatty acid pathway. After blocking spore and biofilm formation, fengycin production reached 302.51 mg/L. Finally, fengycin production was increased to approximately 885.37 mg/L after adding threonine in the optimized culture medium, which was 488-fold higher compared with that of the initial strain. Integrated strain engineering provides a strategy to construct a system for improving fengycin production.

Bioinformatics and Experimental Analysis of the Prognostic and Predictive Value of the CHPF Gene on Breast Cancer

Background

Recent studies in the United States have shown that breast cancer accounts for 30% of all new cancer diagnoses in women and has become the leading cause of cancer deaths in women worldwide. Chondroitin Polymerizing Factor (CHPF), is an enzyme involved in chondroitin sulfate (CS) elongation and a novel key molecule in the poor prognosis of many cancers. However, its role in the development and progression of breast cancer remains unclear.

Methods

The transcript expression of CHPF in the Cancer Genome Atlas-Breast Cancer (TCGA-BRCA), Gene Expression Omnibus (GEO) database was analyzed separately using the limma package of R software, and the relationship between CHPF transcriptional expression and CHPF DNA methylation was investigated in TCGA-BRCA. Kaplan-Meier curves were plotted using the Survival package to further assess the prognostic impact of CHPF DNA methylation/expression. The association between CHPF transcript expression/DNA methylation and cancer immune infiltration and immune markers was investigated using the TIMER and TISIDB databases. We also performed gene ontology (GO) annotation and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis with the clusterProfiler package. Western blotting and RT-PCR were used to verify the protein level and mRNA level of CHPF in breast tissue and cell lines, respectively. Small interfering plasmids and lentiviral plasmids were constructed for transient and stable transfection of breast cancer cell lines MCF-7 and SUM1315, respectively, followed by proliferation-related functional assays, such as CCK8, EDU, clone formation assays; migration and invasion-related functional assays, such as wound healing assay and transwell assays. We also conducted a preliminary study of the mechanism.

Results

We observed that CHPF was significantly upregulated in breast cancer tissues and correlated with poor prognosis. CHPF gene transcriptional expression and methylation are associated with immune infiltration immune markers. CHPF promotes proliferation, migration, invasion of the breast cancer cell lines MCF-7 and SUM1315, and is significantly enriched in pathways associated with the ECM-receptor interaction and PI3K-AKT pathway.

Conclusion

CHPF transcriptional expression and DNA methylation correlate with immune infiltration and immune markers. Upregulation of CHPF in breast cancer promotes malignant behavior of cancer cells and is associated with poorer survival in breast cancer, possibly through ECM-receptor interactions and the PI3K-AKT pathway.

Comparison of structural characteristics and bioactivities of polysaccharides from loquat leaves prepared by different drying techniques

In the present study, freeze drying, hot-air drying, vacuum drying, and microwave drying at the microwave powers of 400, 600, and 800 W, respectively, were utilized to dry loquat leaves for evaluating the effects of different drying techniques on the physicochemical structures and bioactivities of polysaccharides extracted from loquat leaves (LLPs). Results demonstrated that the physicochemical structures and bioactivities of LLPs significantly affected by different drying techniques. The degrees of esterification, molar ratios of constituent monosaccharides, contents of uronic acids, apparent viscosities, and molecular weights of LLPs were varied by different drying techniques. Additionally, LLPs, particularly LLP-M4 which extracted from loquat leaves prepared by microwave drying at the power of 400 W, exerted remarkable in vitro binding capacities, strong inhibitory effects on α-amylase and α-glucosidase, and obvious antioxidant activities. Results indicated that the microwave drying could be an efficient drying technique before extraction of bioactive LLPs, and LLPs had great potential applications in the functional food and pharmaceutical industries.

Structural characterization, antioxidant activity, and immunomodulatory activity of non-starch polysaccharides from Chuanminshen violaceum collected from different regions

Chuanminshen violaceum has been used as an important traditional Chinese medicine and a popular tonic food in China. Polysaccharides are considered the major bioactive components in C. violaceum. In this study, in order well understand the chemical structures and bioactivities of non-starch polysaccharides in C. violaceum (CVPs), the physicochemical structures, antioxidant activities, and immunomodulatory activities of CVPs in C. violaceum collected from different regions of China were investigated and compared. Results showed that the constituent monosaccharides and Fourier transform infrared spectra of CVPs in C. violaceum collected from different regions were similar. However, their molar ratios of constituent monosaccharides, molecular weights, and contents of uronic acids were different. Furthermore, CVPs exerted remarkable antioxidant activities (ABTS and nitric oxide radical scavenging capacities) and immunomodulatory activities (promoted production of nitric oxide, IL-6, and TNF-α from RAW 264.7 macrophages in vitro). Meanwhile, the antioxidant and immunomodulatory activities of CVPs extracted from C. violaceum also varied by cultivated regions. Moreover, results indicated that the antioxidant and immunomodulatory activities of CVPs were closely correlated to their α-1,4-d-galactosiduronic linkages. Results are helpful for better understanding of the structure-bioactivity relationships of CVPs, and beneficial for the improvement of their applications in pharmaceutical and functional food industries.

Quantitative Evaluation of Ultrasound-Assisted Extraction of 1,3-β-glucans from Dictyophora indusiata Using an Improved Fluorometric Assay

In the present study, an improved fluorometric assay based on aniline blue dye for the specific, accurate, and rapid quantification of 1,3-β-glucans in edible mushrooms was developed and fully validated. Furthermore, the improved method was successfully applied for the quantitative evaluation of water soluble 1,3-β-glucans extracted from Dictyophora indusiata by ultrasound-assisted extraction (UAE) with response surface methodology. Results showed that the improved method exhibited high specificity, accuracy, precision, repeatability, and stability, as well as a wide calibration range of 10-600 µg/mL (R2 > 99.9%). The maximum extraction yields of water soluble 1,3-β-glucans (1.20%) and total polysaccharides (5.41%) were achieved at the optimized extraction parameters as follows: ultrasound amplitude (56%), ultrasound extraction time (15 min), and ratio of liquid to raw material (22 mL/g). The results suggest that the improved fluorometric assay has great potential to be used as a routine method for the quantitative evaluation of 1,3-β-glucans in edible mushrooms and that the UAE method is effective for the extraction of 1,3-β-glucans from edible mushrooms.

[The role and mechanism of regulatory T cells in indirect acute lung injury]

Objective: To study the role and mechanism of CD(4)(+) CD(25)(+) FoxP3(+) regulatory T cells (Tregs) in the pathophysiological process of indirect acute lung injury (iALI) in mice. Methods: The iALI model was successfully induced by shock/cecal ligation and puncture method. Sham (n=8), cecal ligation and puncture (CLP, n=10), and hemorrhage (Hem, n=12) groups were established as controls. Two experimental groups were established: CLP+Hem (n=15) without Tregs adoptive transfer (AT), and CLP+Hem with Tregs adoptive transfer (CLP+Hem+AT, n=14). The number of Tregs, subsets of lymphocytes, neutrophil activity, apoptosis, cytokine levels and histopathological changes were measured in the lung tissue of each group. The protein exudation and the expression of IL-10 in bronchoalveolar lavage fluid (BALF) were also detected. After in vitro cell co-culture, the proliferation of activated T cells and the expression of IL-10, INF-γ and iNOS protein were detected. Results: The percentage and the absolute cell number of CD(4)(+) CD(25)(+) FoxP3(+) Tregs in lung tissue of iALI mice were (2.530±0.086)%, and (1.441±0.090)×10(4)/ml, respectively, which were significantly higher than the control groups (P<0.05). Adoptive transfer of Tregs could significantly decrease CD3-positive T lymphocytes, myeloperoxidase (MPO) activity, caspase-3 activity in lung tissue as well as protein leakage in BALF (P<0.05). Meanwhile interleukin-10 (IL-10) levels in lung tissue and BALF were up-regulated from (121.4±43.76) pg/ml to (201.0±61.96) pg/ml (t=2.776, P<0.05) and (206.2±90.88) pg/ml to (339.4±109.5) pg/ml (t=2.477, P<0.05), respectively. Histopathology was also significantly improved. The proliferation of activated T lymphocytes in the adoptive transfer Treg (AT-Treg) group (n=5) was significantly lower than that in the natural regulatory T cell (N-Treg) group (n=5, t=7.485, P<0.01) and the negative control group (n=5, t=16.66, P<0.01). However, iNOS enzyme inhibitor L-NMMA could significantly reduce the T cell proliferation (P<0.05). Conclusion: CD(4)(+)CD(25)(+)FoxP3(+) Tregs could reduce inflammatory reaction in mice with iALI, and the iNOS signaling pathway may be involved in this process.

Somatometric measurements, and clinical chemistry and hematology parameters in Tibetan macaque (Macaca thibetana)

BACKGROUND

Limited physiological data for Tibetan macaques are available at present. This study will provide more rationale for evaluating this species.

METHODS

Thirty-seven Tibetan macaques (15 males and 22 females) were used in this study. Somatometric measurements, clinical chemistry and hematology parameters, insulin, and C-peptide were analyzed.

RESULTS

Females had higher values of waist and waist hip ratio (WHR) than males in somatometric measurements. There were no significant differences between the two genders in hematology. Significant differences between males and females were only found for aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in biochemistry testing. In addition, females had higher fasting insulin and C-peptide than males. There was a strongly positive correlation between age and some somatometric parameters.

CONCLUSIONS

These physiological data will provide veterinarians and researchers with baseline values to evaluate experimental results using Tibetan macaques.

Thigh muscle volume predicted by anthropometric measurements and correlated with physical function in the older adults

OBJECTIVES

(1) to correlate thigh muscle volume measured by magnetic resonance image (MRI) with anthropometric measurements and physical function in elderly subjects; (2) to predict MRI-measured thigh muscle volume using anthropometric measurements and physical functional status in elderly subjects.

DESIGN

Cross-sectional, nonrandomized study.

SETTING

Outpatient clinic in Taiwan.

PARTICIPANTS

Sixty-nine elderly subjects (33 men and 36 women) aged 65 and older.

MEASURMENTS

The anthropometric data (including body height, body weight, waist size, and thigh circumference), physical activity and function (including grip strength, bilateral quadriceps muscle power, the up and go test, chair rise, and five meters walk time) and bioelectrical impedance analysis data (including total body fat mass, fat-free mass, and predictive muscle size) were measured. MRI-measured muscle volume of both thighs was used as the reference standard.

RESULTS

The MRI-measured thigh volume was positively correlated with all anthropometric data, quadriceps muscle power and the up and go test as well as fat-free mass and predictive muscle mass, whereas it was negatively associated with age and walk time. In predicting thigh muscle volume, the variables of age, gender, body weight, and thigh circumference were significant predictors in the linear regression model: Muscle volume (cm3) =4226.3－42.5 × Age (year)－955.7 × gender (male=1, female=2) + 45.9 × body weight(kg) + 60.0 × thigh circumference (cm) (r2 = 0.745, P < 0.001; standard error of the estimate = 581.6 cm3).

CONCLUSION

The current work provides evidence of a strong relationship between thigh muscle volume and physical function in the elderly. We also developed a prediction equation model using anthropometric measurements. This model is a simple and noninvasive method for everyday clinical practice and follow-up.

External beam radiation therapy for inoperable hepatocellular carcinoma with portal vein thrombosis

Portal vein thrombosis (PVT) in patients with hepatocellular carcinoma (HCC) has a poor impact on prognosis. Many of these tumors may cause intrahepatic and extrahepatic metastases. From January 1991 to December 1996, 41 unresectable HCC patients with PVT underwent transcatheter arterial chemoembolization (TACE) and external beam radiation therapy (EBRT) to the portion of PVT. The irradiated field, with a mean equivalent field size of 6.6 x 7.1 cm2, was localized and simulated by abdominal sonography, angiography and computed tomography. Radiation dose ranged from 36 to 66 Gy (mean dose: 51.4 Gy), in a daily fraction of 1.8 to 2 Gy. The response of EBRT was evaluated by abdominal sonography within 3 months of completion of EBRT. The response rates of the PVT after treatment were 39% for complete response (CR), 41% for partial response (PR), and 19% for no response (NR), respectively. The median overall survival time from start of radiotherapy was 10 months for all patients, 17 months for CR patients, 8 months for PR patients and 4 months for NR patients. By multivariate analysis, response of PVT resulted in a significant improvement in survival. (P = 0.001) There was no occurrence of severe complication of radiation-induced liver disease. The results obtained with combined treatment modality of EBRT and TACE in the treatment of HCC patients with PVT are encouraging.

Red blood cell osmotic fragility in chronically hemodialyzed patients

Chronic renal failure induces anemia and a short erythrocyte life span. Red blood cell (RBC) osmotic fragility is the resistance of RBC hemolysis to osmotic changes that is used to evaluate RBC friability. To find the cause of shortened red cell survival in uremic patients, we evaluated the RBC osmotic fragility in 57 chronic hemodialyzed patients. Each patient had received 12 h of dialysis per week continuously prior to being enrolled in the study. Nineteen healthy volunteers served as a control group. Biochemistry, hemoglobin, electrolyte, osmolarity, beta2-microglobulin, and intact parathyroid hormone were examined before and after the dialysis session. To evaluate the osmotic fragility of RBC, blood samples were collected in heparinized test tubes. Fifty microliters of the RBC of each individual was then incubated in solutions containing a series of various concentrations of NaCl ranging from 0 to 0.6%. The concentration of NaCl at which 50% of RBCs were lysed was considered the median osmotic fragility (MOF). The results showed that the MOF was significantly greater in hemodialyzed patients before dialysis than in the control group (0.41 +/- 0.03 vs. 0.39 +/- 0.02%). The osmotic resistance to hemolysis was also recorded after dialysis (MOF 0.38 +/- 0.03%). Correlation analysis showed that the MOF was significantly correlated with urea nitrogen, serum osmolarity, and intact parathyroid hormone level. In addition, the osmotic fragility was higher in patients who had a predialysis intact parathyroid hormone level > 100 pg/dl. In conclusion, hemodialysis can improve the osmotic fragility. The mechanism underlying this improvement may be the removal of low molecular weight uremic toxins, resulting in normalization of serum osmolarity. Our results indicate that parathyroid hormone is probably a major factor influencing RBC osmotic fragility in chronic renal failure.

Talo-navicular arthrodesis for residual midfoot deformities of a previously corrected clubfoot

Triangular navicular, dorsal-lateral subluxation of the talo-navicular (TN) joint with a secondary forefoot cavovarus deformity, and degenerative changes of the TN joint are frequent causes of residual clubfoot deformity and pain in the midfoot after surgical correction. This study investigates the usefulness of TN arthrodesis to correct these deformities and to resolve symptoms resulting from these deformities. During the period from 1991-1996, the senior author performed 19 TN fusions (16 patients) for the above residual clubfoot deformities involving a painful TN joint. Eight of the procedures (seven patients) also required a lateral column shortening with a calcaneal wedge osteotomy to allow for a complete correction of the TN joint. The procedure was only performed in cases involving a hindfoot that was adequately aligned during a previous clubfoot correction. The average age of the patients at the time of surgery was 11 years (range: 4-20). One patient (bilateral procedures) was lost to follow-up. Fifteen patients (17 procedures) were followed-up for an average of four years (range: 2-6). All patients reported symptomatic improvement after the TN arthrodesis. Fourteen of the patients (15 procedures) were completely satisfied. The remaining patient (bilateral procedures) was only partially satisfied due to the subsequent development of navicular-cuneiform osteoarthritis in both feet. Two cases (2 patients) developed complications requiring a second procedure for satisfactory results. In addition, the procedure resulted in an improvement of the talus-first metatarsal angle on both antero-posterior and lateral radiographs. TN arthrodesis produced a correction of the residual clubfoot deformities of the midfoot and resulted in satisfactory clinical improvement in all the patients.

Avascular necrosis in children with acute lymphoblastic leukemia

This study describes the prevalence and demographics of avascular necrosis (AVN) in children with acute lymphoblastic leukemia (ALL). With improving survival of ALL patients on modern chemotherapy regimens, an increasing number of children with AVN will be presenting to orthopaedists. From 1991 to 1996, 202 patients were treated for ALL at a major tertiary pediatric cancer referral center. Eight patients (4.0%) subsequently developed AVN at an average of 30.0 months after beginning chemotherapy. A total of 27 documented joints were involved, with an average of 3.4 joints affected per patient diagnosed with AVN. The subset of patients with high-risk ALL who underwent an aggressive chemotherapy protocol was particularly susceptible to developing AVN. Six of 58 high-risk ALL patients (10.3%) developed AVN at an average of 18.5 months. As ALL patients now frequently survive into adulthood, orthopaedists will be increasingly called on to manage AVN affecting multiple joints in children and young adults.

Solution structure and dynamics of G1TE, a nonphosphorylated cyclic peptide inhibitor for the Grb2 SH2 domain

The solution structure and dynamics of G1TE, a nonphosphorylated cyclic peptide inhibitor for the Grb2 SH2 domain, was determined using two-dimensional NMR and simulated annealing methods. G1TE consists of 10 amino acids and a C-terminal Cys cyclized through its side-chain sulfur atom by a thioether linkage to its N terminus. The results indicate that G1TE assumes a circle-like shape in solution in which all the side chains are protruding outside, and none of the residues are involved in intramolecular hydrogen bonding. The average root-mean-square deviations were found to be 0.41 +/- 0.11 A for the backbone heavy atoms C, Calpha, and N, and 1.03 +/- 0.14 A for all heavy atoms in a family of 10 structures. (15)N relaxation measurements indicate that G1TE has rather restricted dynamics in the fast time scale within its backbone. However, residues Tyr3, Val6, and Gly7 may be involved in a possible conformational exchange. The structural comparison between G1TE in solution and the BCR-Abl phosphopeptide bound to Grb2 SH2 domain revealed that G1TE may form a larger circle-like binding surface than the BCR-Abl phosphopeptide in the bound form. Also, the restricted backbone dynamics of G1TE may result in a reduced loss of entropy and can compensate for the absence of a phosphate group at the Tyr3 position. These structural and dynamic properties of G1TE may provide a molecular basis for understanding its interactions with the Grb2 SH2 domain.

Revision total hip arthroplasty in patients with avascular necrosis

This retrospective study compared the results of revision total hip arthroplasty (THA) in patients with avascular necrosis to patients with osteoarthritis. Twenty-two revision THAs (34 components) in 19 patients with avascular necrosis were compared with 35 revision THAs (55 components) in 31 patients with osteoarthritis. All of the procedures were performed by a single surgeon between 1981 and 1994, and all patients had a minimum of 2 years of follow-up. At the time of revision surgery, the average age was 54 years for the avascular necrosis patients and 67 years for the osteoarthritis patients (P=.002). Clinical and radiographic follow-up was performed for an average of 7 years (range: 2-12 years). Six (18%) components in the avascular necrosis group and nine (16%) components in the osteoarthritis group required re-revision for aseptic loosening an average of 7 years after the original revision (range: 2-11 years). Statistical analysis demonstrated no significant difference between the two groups in regard to the incidence of failure, time to failure, Harris Hip Score, and radiographic appearance. Contrary to expectations derived from the literature on primary THA, no difference was found between the outcome and survivorship of revision THA in patients with avascular necrosis and patients with osteoarthritis, despite a significant difference in age.

Nonoperatively treated displaced bimalleolar and trimalleolar fractures: a 20-year follow-up

This study evaluates the long-term results of displaced bi- and trimalleolar fractures treated closed. Few reports exist in the literature regarding the long-term outcomes of ankle fractures, and none of these specifically addresses displaced bi- and trimalleolar fractures treated nonoperatively. This study analyzed the results of bi- and trimalleolar fractures treated by a single surgeon from 1973 to 1981. As was the standard of care at that time, these fractures were treated nonoperatively if a stable reduction was achieved and maintained. Serial radiographs confirmed the maintenance of reduction in a non-weightbearing long leg cast for 6 weeks and then a short leg walking cast for 6 weeks. Of the 34 patients in this series, 19 were available for review, 10 were deceased, and five were lost to follow-up. The average age at the time of injury was 39 years (range, 17-79 years), and the average length of follow-up was 20 years (range, 16-24 years). At the time of review, only two patients with trimalleolar fractures were minimally symptomatic or had radiographic evidence of mild degenerative changes. The average American Orthopaedic Foot and Ankle Score was 98 of 100 points (range, 87-100 points). This long-term follow-up shows that bi- and trimalleolar fractures can be treated nonoperatively if an anatomic reduction is maintained and closely followed. With reports indicating as much as a 5% deep infection rate and a 10% incidence of loss of reduction after internal fixation, universally recommending an operation for these injuries should be reconsidered, especially in high surgical risk patients.

Diaphyseal forearm fractures treated with and without bone graft

BACKGROUND

The purpose of this study was to determine whether the acute bone grafting of diaphyseal forearm fractures decreases the incidence of nonunion and reduces the time to union. Although the traditional treatment of comminuted radius and/or ulnar shaft fractures involves bone graft, a recent report called into question this practice.

PATIENTS

A database search was used to identify all acute diaphyseal forearm fractures presenting to an urban Level I trauma center between 1988 and 1996. All radius and/or ulnar shaft fractures, as well as all Monteggia and Galeazzi fracture-dislocations, in patients with closed physes were included. The charts and operative reports were available for 64 diaphyseal forearm fractures in 49 patients. Fifty-six fractures were followed for at least 1 year beyond clinical and radiographic union. The injuries were treated with open reduction and plate fixation by experienced orthopedic traumatologists. All noncomminuted fractures were treated without bone graft. For the comminuted fractures, the decision to use bone graft was left to the discretion of the operating surgeon.

RESULTS

Overall, 55 of 56 fractures (98%) achieved union at a mean of 49 days (range, 19-123 days), with the only nonunion occurring in a patient with a closed, noncomminuted Galeazzi injury. Among the 20 noncomminuted fractures, all of which were treated without bone graft, 19 (95%) achieved union at a mean of 50 days (range, 19-102 days). Among the 36 comminuted fractures, all 25 treated without bone graft achieved fusion at an average of 50 days (range, 20-123 days) and all 11 treated with bone graft achieved union at an average of 45 days (range, 22-67 days). No statistically significant difference in the incidence of nonunion or time to union was noted between fractures that were treated with and without bone graft.

CONCLUSION

Acute bone grafting of diaphyseal forearm fractures did not affect the union rate or the time to union.

Aggressive treatment of 119 open fracture wounds

BACKGROUND

The purpose of this study was to determine whether immediate primary closure of open fracture wounds can be performed without increasing the incidence of infections and delayed unions/nonunions. Although the traditional management of these injuries has been open treatment, a trend toward immediate primary closure has evolved on our service.

METHODS

All open fractures presenting to an urban Level I trauma center during a 42-month period were reviewed. Of the 127 patients with open fractures, 90 patients (119 open fractures) were initially treated at the above institution within 24 hours of injury, had fractures proximal to the carpus or tarsals, and were followed-up until fracture union. All patients underwent emergent wound irrigation and debridement. The method of fracture immobilization and timing of wound closure was left to the discretion of the attending orthopedic surgeon. Immediate primary closure was used in 22 of 25 Grade I open fractures (88%), 37 of 43 Grade II fractures (86%), 24 of 32 Grade IIIa fractures (75%), 4 of 12 Grade IIIb fractures (33%), and 0 of 7 Grade IIIc fractures (0%).

RESULTS

Eight fractures (7%) were complicated by a deep wound infection/osteomyelitis, and 19 fractures (16%) developed a delayed union/nonunion. Statistical analysis revealed no significant difference in delayed/nonunion and infection rates between immediate and delayed closures.

CONCLUSION

Immediate primary closure of open fracture wounds after a thorough debridement by an experienced fracture surgeon appears to cause no significant increase in infections or delayed union/nonunions. In addition, early closure may decrease the requirement for subsequent debridements and soft-tissue procedures, thereby minimizing surgical morbidity, shortening hospital stays, and reducing costs. We feel that a randomized, prospective study of this aggressive approach to open fracture care is warranted.

Relationship between microalbuminuria, left ventricular mass and function in essential hypertension

To investigate the relationship of microalbuminuria, left ventricular hypertrophy and hypertension, 150 hypertensive patients were studied. All patients received a series of blood pressure (BP) measurements, overnight urine collection for microalbuminuria determination, chest radiography (CXR), electrocardiography (EKG) and echocardiographic assessment. Echocardiographic variables including left ventricular mass index (LVMI), fractional shortening (FS) and Doppler mitral flow E/A ratio were analyzed. Patients were divided into 4 groups according to diastolic blood pressure. Left ventricular hypertrophy (LVH) was identified by EKG in 28 patients (18.7%), by CXR in 56 patients (37.3%) and by echocardiography in 126 patients (89.3%). Microalbuminuria was detected in 42 patients (28%). Microalbuminuria tended to present in patients with higher systolic, diastolic and mean blood pressure. There was no relation between FS and E/A ratio and the degree of blood pressure elevation. However, there was a strong correlation between microalbuminuria and LVMI (p < 0.001), this correlation was not related to any difference in blood biochemistry. The results of this study indicate that the severity of microalbuminuria relates closely to the severity of hypertension. In addition, hypertensive patients with microalbuminuria tend to have higher LVMI.

Complete atraumatic rupture of the flexor hallucis longus tendon: a case report and review of the literature

A complete atraumatic rupture of the flexor hallucis longus tendon in a patient without systemic disease is a rare occurrence. Although four cases of complete traumatic ruptures have been cited in the literature, only one case of a complete atraumatic rupture has been previously reported. Presented here is a second case with a review of the literature and a discussion of the surgical indications.

Major causes of diabetic death at one hospital

Death certificates filed between 1987 and 1990 at the Kaohsiung Medical College Hospital (KMCH) were reviewed to investigate causes of diabetic death. During this period, 1,383 patients expired at KMCH, of which 151 had diabetes mellitus. The major causes of death in these 151 diabetic patients were infection in 25.8%, cardiovascular disease in 18.5%, cerebrovascular disease in 11.3%, uremia in 8.6% and diabetic ketoacidosis in 1.3%, while diabetes was reported as the contributory or underlying cause of death. Malignancy in 12.0%, liver disease in 5.3%, trauma in 1.3% and upper gastroenteral bleeding in 0.7%, likewise, were among the leading causes of death irrespective of underlying diabetes. However, cause of death in 15.2% of these diabetic patients was undetermined. Our analysis revealed that infection and cardiocerebrovascular disease were the leading problems contributing to diabetic death. Therefore, reducing the risk of infection by strict glycemic control, intensive medical intervention in infection and the proper prevention of diabetic angiopathy-related risk factors and complications are imperative for the reduction of diabetic mortality in our patients.

Remission of hypoplastic acute leukemia by low dose Ara-C: one case report

The occurrence of hypoplastic acute leukemia is widely recognized as an atypical leukemia, and is defined as hypocellular marrow with more than 30% blasts and none or few blasts in the circulating blood. The pathogenesis of hypoplastic acute leukemia is still unknown. Clinically, it usually follows a less progressive course and has a high prevalence rate among the elderly. The treatment and prognosis remains unclear. We present a case of hypoplastic acute leukemia, which responded well to low dose Ara-C. The 67 year-old female patient had symptoms of bruising easily and dizziness for about 3 years. Initial investigation revealed pancytopenia in the circulating blood and hypocellularity (10%) with blast cells (60%) in the bone marrow. Besides supportive treatment with blood transfusions and antibiotics, chemotherapy of low dose Ara-C 10 mg/m2 was administrated for 14 days by subcutaneous injection. Bone marrow examination revealed an increase of cellularity and a decrease of blast cells following chemotherapy. Anemia and thrombocytopenia also simultaneously improved. Such results may suggest induction of differentiation effect of low dose Ara-C in hypoplastic leukemia.