Mutation analysis of Wilson disease in Taiwan and description of six new mutations

Wilson disease is an autosomal recessive disorder of copper metabolism. Mutation screening in Wilson disease has led to the detection of at least 89 disease-specific mutations. Some mutations appear to be population specific, while others are common to many populations. In this study, 38 Taiwanese patients with Wilson disease were screened using single-strand conformation polymorphism analysis, followed by direct DNA sequencing. We found 12 different mutations, six of which were novel. All our detected mutations were found to be in eight exons. Four mutations in three loci (Arg778Gln, Arg778Leu, Gly943Asp, and Pro992Leu) accounted for about 58% of the mutant alleles we detected. Using an RNA transcriptional assay, we confirmed that both of our detected splice-site mutations resulted in exon skipping.

[Long-term outcome studies of hyperactive children: literature review]

The attention deficit hyperactive disorder (hereinafter ADHD, children with this disease usually are named hyperactive children) is often one of the most frequent diagnosis of psychiatric outpatients for children. Though there are still some disputes in diagnosis, child psychiatrists can diagnose individual cases through interview, observation and the information provided by their parents and teachers. Besides the diagnosis and treatment, the result of long-term follow-up studies of hyperactive children also gradually indicate the most extreme signification. According to the long-term outcome studies of hyperactive children conducted in foreign countries for the past 20 to 30 years, symptoms of hyperactive children will not disappear completely as they grew up; instead, the residual symptoms can cause adaptive impairment in their adolescent and adult period. The core symptoms of ADHD (inattention, hyperactivity, impulsive behavior) can be satisfactorily managed if they can be diagnosed as earlier as possible, through medicine and behavioral therapy, plus medical staff and cooperation from family, school and society. If there is no early diagnosis or intervention, and let symptoms continue, after growing up, associated conduct problem or disorder, antisocial behavior, substance abuse and antisocial personality disorder, even criminal behavior will have higher opportunity to develop into adolescence and adulthood. These behavioral problems will cause very serious social problems. We have became more clearly aware of the accurate recognition of hyperactive children and have emphasized its importance in recent years. Unfortunately, there are still no long-term follow-up study reports regarding these children in our country; therefore we could not discover the effective predictors and higher risk groups for early intervention and prevention. This paper aims at reviewing long-term outcome studies of hyperactive children and trying to organize its adaptive problems and associated mental disorders after growing up. We also expect that the long-term follow-up studies on hyperactive children can be seen in the very near future at our country.

The prenatal diagnosis of Pierre-Robin sequence

The purpose of this study was to evaluate the spectrum of prenatal sonographic and chromosomal findings, associated anomalies and perinatal and neonatal outcomes in cases with Pierre-Robin sequence. All cases (20) with Pierre Robin sequence, who were born at China Medical College Hospital between 1990 and 1997, were included and analysed in this series. 12 pregnancies (60 per cent) were complicated by polyhydramnios and 9 (45 per cent) were combined with cleft palate. Four cases (20 per cent) with cardiac anomalies were also observed. Two fetuses (10 per cent) had abnormal karyotyping (one trisomy 21, one trisomy 18). All fetuses were delivered at or near term. Male deviation was observed in cases with isolated Pierre-Robin sequence or combined mild anomalies (male female ratio: 13:3). Two neonatal mortalities and three with mental retardation were observed. This investigation provides a basis for counselling patients with fetal micrognathia or neonatal Pierre-Robin sequence. The main prenatal sonographic findings of Pierre-Robin sequence are micrognathia, polyhydramnios and cleft palate. In cases of polyhydramnios, sonographic examination of the facial profile and palate are recommended. After the finding of polyhydramnios, micrognathia, and even cleft palate, clinicians should be aware of the possibility of neonatal Pierre-Robin sequence. Cardiac evaluation and karyotyping is also recommended.

Structural and functional analysis of the 3' untranslated region of bamboo mosaic potexvirus genomic RNA

The secondary structure of a 170 nt transcript derived from a cDNA clone containing the 3' untranslated region of bamboo mosaic potexvirus (BaMV) with 32 adenine residues of the poly(A) tail, was investigated in solution by using enzymatic and chemical probes. Three consecutive stem-loops forming a cloverleaf-like structure (domain ABC) and a major stem-loop (domain D) containing a bulge and an internal loop were identified as connected to a previously identified pseudoknot domain (domain E) comprising at least 13 adenylate residues of the 3' poly(A) tail. The highly conserved hexamer nucleotides (ACc/uUAA) among potexviruses are located in loop D and the putative polyadenylation signal (AAUAAA) is located in the internal loop of domain D. Based on the data of the structural probing, a three-dimensional structure was modeled. Mutants with domain ABC deleted showed no detectable signal in protoplasts, while changes in domain D, except for the bulge deletion, showed interference of BaMV RNA accumulation in protoplasts. Mutants with disrupted stem D formation impaired BaMV accumulation. However, the mutant with compensatory mutations restored stem formation which could only improve the viral accumulation to 58 % that of the wild-type structure.

Multiple pterygium syndrome: report of one case

Multiple pterygium syndrome is a rare autosomal recessive disease which is characterized by multiple pterygium across the major joint and other associated anomalies. In this article, we report a male premature infant who was born with bizarre appearance: mask face with low set ear and micrognathia; pterygium of neck, antecubital, popliteal and intercrural area with four extremities flexion contracture. He was thought to be the first case report in Taiwan. Besides, we review medical literature about this disease.

Development of a biodegradable antibiotic delivery system

Antibiotic beads have been used as a drug delivery system for the treatment of various surgical infections. In this study, the copolymer 50:50 poly(DL-lactide):co-glycolide was mixed with vancomycin powder and hot compressing molded at 55 degrees C to form five types of biodegradable antibiotic beads. The beads were placed in 1 mL of phosphate buffered saline and incubated at 37 degrees C. The phosphate buffered saline was changed daily, and the removed buffer solutions were stored at -70 degrees C until the antibiotic concentration in each sample was determined by high performance liquid chromatography system assay. The concentration of vancomycin in each sample was well above the breakpoint sensitivity concentration (the antibiotic concentration at the transition point between bacterial killing and resistance to the antibiotic) for more than 32 days. The release was most marked during the first 48 hours. All copolymer 50:50 poly(DI lactide):co-glycolide biodegradable beads released high concentrations of the antibiotics in vitro for the time needed to treat bone infections (4 to 6 weeks). The diameter of the sample inhibition zone ranged from 6.5 mm to 10 mm, and the relative activity of vancomycin ranged from 12.5% to 100%. Copolymers with low heat of formation temperatures are required for making a controlled release system to prevent antibiotic decomposition, which occurs when using the hot compressing molded method. The rate and duration of release from the antibiotic beads can be adjusted by varying the diameter of the beads. This offers a convenient method to adjust the release rate to meet the specific antibiotic requirements for different patients.

Spondyloepiphyseal dysplasia congenita: report of one case

Spondyloepiphyseal dysplasia (SED) congenita is a rare disorder with autosomal dominant inheritance which demonstrates short stature since birth and displays progressive involvement of the spine and the epiphyses of long bones. We present a case of SED congenita with short stature since birth, flat midface, short neck, barrel chest with pectus carinatum, lumbar lordosis, myopia without retinal detachment, and flat, avoid-shaped vertebral bodies. Neurological examination is normal. No specific biochemical change or intellectual impairment can be discerned.

Mutation analysis of the PTEN/MMAC1 gene in cancers of the digestive tract

The 10q23.3 gene PTEN (phosphatase and Tensin homologue deleted on chromosome 10) or MMAC1 (mutated in multiple advanced cancers 1) was recently reported to undergo frequent mutation, including mutations and deletions in multiple advanced cancers. This study showed that the aberrant transcripts of this gene are frequently found in cancers of the digestive tract, paired non-cancerous tissues and normal peripheral mononuclear cells. Sequence analysis of the aberrant transcripts revealed three types of deletions: (i) a deletion junction with a splicing-like donor or acceptor sequence; (ii) several-base homology near or between the donor acceptor site at the deletion junction; and (iii) deletion with insertion. From these results, it is suggested that aberrant transcripts of PTEN/MMAC1 found by nested reverse transcription-polymerase chain reaction are a common (or natural) phenomenon unrelated to oncogenesis. The mechanism producing these aberrant transcripts needs further investigation. Using single-strand conformation polymorphism and direct sequencing to analyse for small base changes of the genomic DNA of the PTEN/MMAC1 gene revealed no point mutations or small base changes.

Bacillus popilliae endocarditis with prolonged complete heart block

Bacillus popilliae, a fastidious, aerobic, gram-positive, spore-forming bacillus, has never been reported as a pathogen in human infectious diseases. We report the first case of a human infected by the pathogen B. popilliae, which presented as endocarditis involving the bicuspid aortic valve and complicated with prolonged (> 30 days; to our knowledge, the longest in the literature) complete heart block. Although surgery may be warranted by previous reports, the patient was successfully managed by medical treatment instead, because of the absence of evidence from various approaches that support the existence of perivalvular extension of infection.

Down-regulation of L-type calcium channel and sarcoplasmic reticular Ca(2+)-ATPase mRNA in human atrial fibrillation without significant change in the mRNA of ryanodine receptor, calsequestrin and phospholamban: an insight into the mechanism of atrial electrical remodeling

OBJECTIVES

We investigated the gene expression of calcium-handling genes including L-type calcium channel, sarcoplasmic reticular calcium adenosine triphosphatase (Ca(2+)-ATPase), ryanodine receptor, calsequestrin and phospholamban in human atrial fibrillation.

BACKGROUND

Recent studies have demonstrated that atrial electrical remodeling in atrial fibrillation is associated with intracellular calcium overload. However, the changes of calcium-handling proteins remain unclear.

METHODS

A total of 34 patients undergoing open heart surgery were included. Atrial tissue was obtained from the right atrial free wall, right atrial appendage, left atrial free wall and left atrial appendage, respectively. The messenger ribonucleic acid (mRNA) amount of the genes was measured by reverse transcription-polymerase chain reaction and normalized to the mRNA levels of glyceraldehyde 3-phosphate dehydrogenase.

RESULTS

The mRNA of L-type calcium channel and of Ca(2+)-ATPase was significantly decreased in patients with persistent atrial fibrillation for more than 3 months (0.36+/-0.26 vs. 0.90+/-0.88 for L-type calcium channel; 0.69+/-0.42 vs. 1.21+/-0.68 for Ca(2+)-ATPase; both p < 0.05, all data in arbitrary unit). We further demonstrated that there was no spatial dispersion of the gene expression among the four atrial tissue sampling sites. Age, gender and underlying cardiac disease had no significant effects on the gene expression. In contrast, the mRNA levels of ryanodine receptor, calsequestrin and phospholamban showed no significant change in atrial fibrillation.

CONCLUSIONS

L-type calcium channel and the sarcoplasmic reticular Ca(2+)-ATPase gene were down-regulated in atrial fibrillation. These changes may be a consequence of, as well as a contributory factor for, atrial fibrillation.

Profile of cytokine expression in nasopharyngeal carcinomas: a distinct expression of interleukin 1 in tumor and CD4+ T cells

Nasopharyngeal carcinoma (NPC) is an epithelial cancer that is causally associated with Epstein-Barr virus (EBV) infection. NPC tumor biopsies are characterized histopathologically by an abundant infiltration of nonmalignant lymphocytes. We analyzed the expression of various cytokines in NPC tissues to investigate the interaction of the infiltrating lymphocytes and tumor cells. Analysis using reverse transcriptase-PCR revealed the expression of a panel of cytokines in the NPC biopsies: interleukin (IL)-1alpha, IL-1beta, IL-2, IL-4, IL-5, IL-6, IL-10, IFN-gamma, tumor necrosis factor-alpha, transforming growth factor-beta, and IL-1 receptor types I and II. Elevated expression of IL-1alpha and IL-1beta was observed in primary tumors and NPC metastases compared to control tissues. Interestingly, this increased expression correlated with the EBV-encoded viral IL-10 transcript. To determine which cells were responsible for producing IL-1, we determined the cellular constituents of NPC biopsies by immunoflow cytometric analysis. On the basis of data from these analyses, the three major specific cell populations, epithelial cells, CD4+ T cells, and CD8+ T cells, were selected from five NPC tumors using specific, antibody-coated paramagnetic beads. Reverse transcriptase-PCR of RNA from these fractionated cells showed that transcripts of IL-1alpha and IL-1beta were present not only in the malignant epithelial cells but also in CD4+ T cells infiltrating the tumor, a finding confirmed by immunohistochemical staining. We hypothesize that the unusual synthesis of IL-1alpha and IL-1beta by EBV-positive epithelial cells as well as by CD4+ T cells might contribute to lymphocyte infiltration and/or tumor growth during NPC development.

Sufficient length of a poly(A) tail for the formation of a potential pseudoknot is required for efficient replication of bamboo mosaic potexvirus RNA

RNAs transcribed from a full-length infectious cDNA clone of the bamboo mosaic potexvirus (strain O) genome, pBaMV-O, were infectious to Nicotiana benthamiana plants. Mutant genomes in which the poly(A) tail is absent or replaced by a 3' tRNA-like structure from turnip yellow mosaic virus RNA failed to amplify detectably in N. benthamiana protoplasts. No amplification was detected in protoplasts inoculated with transcripts containing 4, 7, or 10 adenylate residues at the 3' end, whereas transcript inocula with 15 adenylate residues resulted in coat protein accumulation to a level 26% of that resulting from inoculation with transcripts with 25 adenylate residues (designated as wild type). Coat protein accumulation levels of 69 and 98% relative to wild type were observed after inoculation of protoplasts with transcripts bearing poly(A) tails 18 and 22 nucleotides long, respectively. The presence of a putative 3' pseudoknot structure including at least 13 adenylate residues of the 3'-terminal poly(A) tail was supported by enzymatic and chemical structural analysis. The functional relevance of this putative pseudoknot was tested by mutations that affected basepairing within the pseudoknot. These results support the existence of functional 3' pseudoknot that includes part of the 3' poly(A) tail.

Prenatal diagnosis of dyssegmental dysplasia. A case report

BACKGROUND

Since the first use of sonography, most fetal dwarfism has been detectable prenatally. The correct differentiation of the subtype of dwarfism is difficult at times. Dyssegmental dysplasia is probably an exception to these subtypes because the vertebral disorganization and occipital encephalocele at times permits prenatal diagnosis.

CASE

A 34-year-old woman, gravida 3, para 1, elective abortion 1 for dwarfism, was referred at 27 weeks' gestation for cystic hygroma. Further sonographic findings included: cystic hygroma with massive ascites, micromelia, occipital encephalocele, spinal disorganization and hydramnios. The fetus and both parents appeared to have a normal karyotype. Later the pregnancy was terminated with vaginal delivery. The fetus had micromelia, camptomelia, cystic hygroma, a flat face, short neck, short trunk, narrow thorax with protuberant abdomen, scoliosis and clubfeet.

CONCLUSION

Sonography is effective in prenatal diagnosis of dyssegmental dysplasia. With sonography, diagnosis of dyssegmental dysplasia becomes possible as early as the first trimester.

Influence of perinatal factors on limit of viability in extremely low birth weight infants

This retrospective study investigated the influence of perinatal factors on the limit of viability in extremely low birth weight (ELBW) infants. From January 1997 to May 1998, all infants weighing less than 1000 gm admitted to NICU of China Medical College Hospital were enrolled in this study. Still-born infants and infants with congenital anomaly were excluded. The end outcome was survival of the infants (defined as alive at discharge). Eighty-four infants were included in this study. Their mean gestational age (GA) was 25.8 +/- 1.76 weeks, mean birth weight (BW) was 772 +/- 114 gm, and overall survival rate was 48.8%. The smallest intact survival was a female infant of GA 23 weeks and BW 530 gm. Early neonatal mortality rate (< 7 days) was 26.2% (23/84). The cut off levels, below which mortality significantly increased, were GA < 24 weeks and BW < 700 gm (odds ratio, 6.11, confidence interval, 2.01 to 18.63 for GA; odds ratio, 2.65, confidence interval, 1.09 to 6.39 for BW). The two most significant factors which independently affected neonatal survival were GA < 24 weeks and early neonatal dexamethasone treatment for the prevention of chronic lung disease (odds ratio, 9.24, confidence interval, 2.53 to 33.76 for GA; odds ratio, 35.83, confidence interval, 7.03 to 183 for dexamethasone treatment). We conclude that in order to further reduce neonatal mortality, efforts should be made in the areas of prenatal care and women's health to prevent extreme prematurity and low birth weight infants. In the case of an impending delivery of an ELBW infant, an active plan of management for all gestations > or = 24 weeks seems appropriate. Finally, unless it is proven to be safe, early neonatal dexamethasone treatment for prevention of chronic lung disease should not be routinely used in ELBW infants.

The significance of early subtle coronary arterial lesions on echocardiogram in Kawasaki disease

Intensive echocardiographic studies were undertaken in 37 patients with Kawasaki disease (KD) and 12 febrile controls during the acute stages. Video-tape recordings were read doubly-blinded by 3 pediatric cardiologists at 2 hospitals. Three characteristics of subtle coronary arterial lesions, including contour of lumen, smoothness of endothelium and sono-homogeneity of the surrounding tissue were particularly described. Seven of the 37 KD patients (19%) were found to have coronary arterial aneurysms (CAA) at the end of the convalescent stage. The 3 cardiologists agreed in the diagnosis of the subtle lesions by 72%. More patients with Kawasaki disease were found to have an irregular endothelium than the controls (P < 0.001). KD patients later complicated with CAA were more likely to have had the three characteristics of subtle coronary lesions during the acute stage than the KD patients without aneurysms (P < 0.001). Also, the coronary arterial size measured during the acute stage were found to be positively correlated with their largest dilatation at the convalescent stage (P = 0.0001, r = 0.61). We conclude that early subtle coronary arterial lesions can herald the development of coronary arterial aneurysms.

Kawasaki disease complicated by peripheral gangrene

An 8.5-month-old male infant with Kawasaki disease (KD) received high-dose intravenous immunoglobulin (IVIG) therapy on the fifth day after fever onset. However, multiple peripheral limb ischemias occurred 2 days later. Accordingly, heparin followed by dipyridamole was administered. Aside from a small amputation at the tip of the right middle finger, all other digital ischemias resolved. This presentation demonstrates that early recognition and management of peripheral gangrene in KD may keep its sequela to a minimum.

Different race, different face: minor anomalies in Chinese newborn infants

OBJECTIVE

To define the nature and incidence of minor anomalies in Chinese newborn infants and to evaluate the validity of the hypothesis that infants with three or more minor surface anomalies will also have a major malformation.

METHODS

A total of 3,345 Chinese newborn infants were examined based on a list of 67 items of minor anomalies.

RESULTS

About 44.9% of the newborn infants had at least one minor anomaly that was unrelated to gender, maternal age, or gestational age, but significantly associated with fetal presentation. Breech-presented newborn infants had double the risk of minor anomalies. Simian crease, upward slant and frontal bossing could be considered normal variants for Chinese newborn infants, because the incidence of each was higher than 4%.

CONCLUSIONS

Although some studies have shown that approximately 90% of infants having three or more minor anomalies are associated with a major malformation, we found only a 10.1% predictive value based on this study. Nevertheless, we suggest that infants with three or more minor anomalies be carefully evaluated for the possibility of major malformation in order to provide early management.

Child with velocardiofacial syndrome and del (4)(q34.2): another critical region associated with a velocardiofacial syndrome-like phenotype

We report on a child with congenital heart disease (atrial septal defect, ventricular septal defect, pulmonic stenosis), submucosal cleft palate, hypernasal speech, learning difficulties, and right fifth finger anomaly manifestations, consistent with velocardiofacial syndrome (VCFS); however, cytogenetic analysis demonstrated a small terminal deletion of the segment 4q34.2 to 4qter. Fluorescent in situ hybridization did not identify a deletion of the critical region associated with VCFS. In previously reported 4q deletions with a breakpoint distal to 4q34.2, no cardiac defects or cleft of palate were reported. Our patient has a deletion of 4q34.2 to 4qter and has palate and cardiac involvement and minor learning difficulties, which implies that genes involved in heart and palate development lie distal to 4q34.2, and that the critical region for more severe mental retardation on 4q may reside proximal to 4q34.2. These results suggest that a distal 4q deletion can lead to a phenotype similar to VCFS and emphasizes the importance of searching for other karyotype abnormalities when a VCFS-like phenotype is present and a 22q deletion is not identified.

Cutaneous telangiectasias, sparse hair, and type I membranoproliferative glomerulonephritis

We report the unusual association of normocomplementemic type I membranoproliferative glomerulonephritis in a 10-year-old girl with sparse red hair, absent eyebrows and eyelashes, cutaneous telangiectasias, and an atrial septal defect.

Hepatic abscess due to gastric perforation by ingested fish bone demonstrated by computed tomography

Perforation of the gastrointestinal tract by ingested foreign bodies is rare. Preoperative diagnosis of complications due to foreign bodies in the gastrointestinal tract can rarely be achieved because the conventional radiographic appearance is nonspecific. This report describes a 69-year-old woman who presented with vague clinical manifestations, intermittent abdominal pain, and low-grade fever. Hepatic abscess, secondary to a foreign body penetrating the gastric wall, was diagnosed preoperatively using computed tomography findings. On exploration, the foreign body turned out to be a fish bone. The abscess was confirmed and drained during surgery and a partial gastrectomy was performed. This case illustrates the value of CT in the evaluation of this condition.

The major immunogenic epitopes of Epstein-Barr virus (EBV) nuclear antigen 1 are encoded by sequence domains which vary among nasopharyngeal carcinoma biopsies and EBV-associated cell lines

Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1) is a protein expressed consistently in EBV-infected cells and EBV-associated malignant tissues. A panel of monoclonal antibodies (MAbs) was generated against the C terminus of EBNA-1 and evaluated for the detection of EBNA-1 in different cell lines. The epitopes recognized were mapped. Since sequence variations of EBNA-1 have been reported in nasopharyngeal carcinoma (NPC) tissues and in infected healthy individuals, the ability of these MAbs to recognize a recombinant protein derived from an NPC biopsy was also analysed. MAb 4H11 appeared to react with EBNA-1 sequences from different sources, whereas MAbs 5C11, 5F12 and 8F6 failed to recognize a recombinant EBNA-1 protein cloned from an NPC patient. Using different recombinant EBNA-1 fragments in an immunoblot format, this study demonstrates that the domain bounded by amino acids 408 and 498 is very immunogenic in mice in that epitopes in this region are recognized by various MAbs. Amino acid sequences of EBNA-1 were also deduced from nucleotide sequences amplified from three Burkitt's lymphoma cell lines, two spontaneous lymphoblastoid cell lines, two NPC biopsies and one NPC hybrid cell line, NPC-KT, and compared to the sequence from B95-8. The amino acid sequence of EBNA-1 in Akata is almost identical to that in an NPC biopsy, except for amino acid 585. The results of this study indicate that the immunogenic epitopes of EBNA-1 are highly variable.

Apoptosis in primary cutaneous amyloidosis

Amyloid deposits in primary cutaneous amyloidosis (PCA) may be initially derived from cytokeratin. possibly after keratinocyte death. However, the mechanism of keratinocyte death remains obscure. To investigate the potential role of apoptosis in the pathogenesis of PCA, a retrospective study was conducted on the skin tissues from 20 Chinese patients with PCA. We used a terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL) method for detecting the apoptotic cells. Immunohistochemical staining was performed to examine the expression of the B-cell leukemia/lymphoma-2 gene (bcl-2) and Fas. Apoptotic cells were shown in 11 of 20 cases (55%) by TUNEL. Histological sections showed that dyskeratotic cells and vacuolar alteration of the basal cells were more commonly observed in the TUNEL-positive group. In all cases of PCA, epidermal expression of bcl-2 was minimal, while expression of Fas was observed on keratinocytes in the basal to granular layers: however, these findings were not different from those in normal skin. Our results suggest that the keratinocyte destruction in PCA may occur as an initial result of apoptosis, which in turn leads to the amyloid formation.

In vitro elution of vancomycin from biodegradable beads

The current antibiotics delivery system for orthopedic infection treatment uses polymethylmethacrylate (PMMA) beads as a drug release. However the nonbiodegradable nature of the PMMA necessitates a second operation to remove the beads. This article explores the alternative of using biodegradable polymers as antibiotic beads for a long-term drug release. The effect of different processing factors on the release rate of the beads was investigated. To manufacture an antibiotic bead, polylactide-polyglycolide copolymers were mixed with vancomycin. The mixture was compressed and sintered at 55 degrees C to form beads of different sizes. An elution method was employed to characterize the release rate of antibiotic over a 35-day period at 37 degrees C. Biodegradable beads released high concentrations of antibiotic (well above the breakpoint sensitivity concentration) in vitro for the period of time needed to treat bone infection; i.e., 4-6 weeks. A bacterial inhibition test was carried out to determine the relative activity of the released antibiotics. The diameter of the sample inhibition zone ranged from 6.5-10 mm, which is equivalent to 12.5-100% of relative activity. By changing the processing parameters, we were able to control the release rate of the beads. This provides advantages of meeting the specific antibiotics requirement for patients with various surgical infections.