Application of infrequent-restriction-site PCR to clinical isolates of Acinetobacter baumannii and Serratia marcescens

We applied infrequent-restriction-site PCR (IRS-PCR) to the investigation of an outbreak caused by 23 isolates of Acinetobacter baumannii in an intensive care unit from November 1996 to May 1997 and a pseudoepidemic caused by 16 isolates of Serratia marcescens in a delivery room from May to September 1996. In the epidemiologic investigation of the outbreak caused by A. baumannii, environmental sampling and screening of all health care workers revealed the same species from the Y piece of a mechanical ventilator and the hands of two health care personnel. IRS-PCR showed that all outbreak-related strains were genotypically identical and that three strains from surveillance cultures were also identical to the outbreak-related strains. In a pseudoepidemic caused by S. marcescens, IRS-PCR identified two different genotypes, and among them one genotype was predominant (15 of 16 [93.8%] isolates). Extensive surveillance failed to find any source of S. marcescens. Validation of the result of IRS-PCR by comparison with that of field inversion gel electrophoresis (FIGE) showed that they were completely concordant. These results suggest that IRS-PCR is comparable to FIGE for molecular epidemiologic studies. In addition, IRS-PCR was less laborious and less time-consuming than FIGE. To our knowledge, this is the first report of the application of IRS-PCR to A. baumannii and S. marcescens.

Effects of low oxygen condition on the generation of reactive oxygen species and the development in mouse embryos cultured in vitro

OBJECTIVE(S)

To elucidate the relationship between intracellular H2O2 production and embryo development in different oxygen culture conditions.

METHODS

Pronuclear stage embryos were obtained from C57BL/CBA F1 and ICR mice. Measurement of H2O2 level was performed with 2',7'-dichlorodihydroflourescein diacetate and the number of blastomeres was counted after staining with 4',6'-diamidino-2-phenylindole.

RESULTS

Regardless of strains, H2O2 level reached a peak at the 2-cell stage in 20% O2. But in embryos cultured in 5% O2 it was significantly lower at the 2-cell and 4-cell stages compared to those from 20% O2. The embryos cultured in 20% O2 showed developmental delay or block, but in 5% O2 these phenomena were overcome and the development was significantly increased with an infrequent fragmentation.

CONCLUSIONS

Our data suggest that the 5% O2 decreases the relative concentration of H2O2 and results in improved embryo development in terms of quantity and quality without regard to type of strains.

Open reduction of condylar neck fractures with exposure of the facial nerve

OBJECTIVE

The purpose of this study was to evaluate the clinical and radiologic results in patients whose condylar neck fractures were reduced and stabilized through use of a standard preauricular approach involving systematic exposure of the facial nerve.

STUDY DESIGN

We performed open reductions of high condylar neck fractures with exposure of the facial nerve in a prospective series of 34 patients. In this article, we describe clinical and radiologic results in 25 patients with follow-up longer than 6 months.

RESULTS

Immediate postoperative radiographs showed excellent reduction of the fractures in 24 patients. The postoperative course was uneventful in most patients. The incidence of complications was low; there were 5 patients with temporary facial nerve palsies, 3 patients with plate fractures or screw loosenings, 5 patients with transitory auricular hypoesthesia, 1 patient with inadequate reduction, and 1 patient with limited mouth opening.

CONCLUSIONS

The results of this study showed that accurate reduction and rigid fixation of high condylar neck fractures were possible through use of an approach in which the facial nerve was exposed.

Effect of polyethylene wear on osteolysis in cementless primary total hip arthroplasty: minimal 5-year follow-up study

We measured polyethylene wear radiographically in 85 cementless primary total hip arthroplasties. All patients were followed up for at least 5 years (mean, 6.3 years). The mean extent of linear wear was 0.88 mm, and the mean rate of linear wear was 0.14 mm/y. The mean volumetric wear was 539.42 mm3, and the mean rate of volumetric wear was 87.69 mm3/y. Polyethylene wear was correlated inversely with the patients' age only and was not influenced by other clinical factors. Osteolysis developed in 34 femurs and in 11 acetabula. Radiographic loosening was found in 2 cases in the femur and none in the acetabulum. Polyethylene wear was significantly correlated with frequency and size of osteolytic lesions. Therefore, polyethylene wear was considered one of the major causes of osteolysis, but it was not directly associated with prosthesis loosening. To reduce the extent of polyethylene wear, the material characteristics of polyethylene should be improved, or more durable articulating materials should be developed.

A common mutation in the methylenetetrahydrofolate reductase gene is a determinant of hyperhomocysteinemia in epileptic patients receiving anticonvulsants

Hyperhomocysteinemia is a condition caused by both genetic and nongenetic factors. To determine whether a common methylenetetrahydrofolate reductase (MTHFR) variant is related to elevated homocysteine concentrations in epileptic patients receiving anticonvulsants, we investigated the plasma total homocysteine (tHcy) level, folate level, and MTHFR 677 C --> T mutation using a polymerase chain reaction (PCR) and restriction fragment length polymorphism analysis with HinfI digestion in 103 patients with epilepsy and 103 normal controls. The prevalence of hyperhomocysteinemia (> or = 11.4 micromol/L, 90th percentile of control group) was higher in patients than in controls (25% v 10.0%, P = .007). The homozygosity for the 677 C --> T mutation of MTHFR was associated with elevated tHcy and low folate levels. The magnitude of hyperhomocysteinemia in MTHFR TT homozygotes was more pronounced in epileptic patients than in controls (18.2 +/- 1.6 v 9.1 +/- 1.2 micromol/L, P = .04). In epileptic patients, hyperhomocysteinemia was more frequent in MTHFR TT genotypes versus CT or CC genotypes (58% v 17% and 16%, P < .001). Multiple logistic regression analysis showed that MTHFR TT genotype was an independent predictor of hyperhomocysteinemia in epileptic patients receiving anticonvulsants (phenytoin and carbamazepine but not valproic acid), suggesting that gene-drug interactions induce hyperhomocysteinemia. These findings indicate that epileptic patients receiving anticonvulsants may have a higher folate requirement to maintain a normal tHcy level, especially homozygotes for MTHFR 677 C --> T mutation.

A case of sternal insufficiency fracture

We report a case of insufficiency fracture of the sternum in a 70-year-old female patient with a review of the literature. She complained of sudden onset chest pain and aggravating dyspnea. She has been managed with corticosteroid due to chronic obstructive pulmonary disease for 15 years. Diagnosis of sternal insufficiency fracture presented with thoracic kyphosis was made on the basis of absence of trauma history, radiologic findings of lateral chest radiograph, bone scintigraphy and chest computed tomography. Thoracic kyphosis and osteoporosis secondary to menopause, corticosteroid therapy and limited mobility due to chronic obstructive pulmonary disease were considered as predisposing factors of the sternal insufficiency fracture in this patient.

Moderate hyperhomocyst(e)inemia is associated with the presence of coronary artery disease and the severity of coronary atherosclerosis in Koreans

To examine whether moderate hyperhomocyst(e)inemia is associated with coronary artery disease and the number of diseased coronary vessels in Koreans, we investigated 201 patients with angiographically documented coronary artery disease and 187 healthy subjects without evidence of stroke and coronary artery disease. The mean plasma total homocysteine in patients was higher than in controls (10.3 micromol/L; 95% confidence interval, 7.0-13.6 vs. 8.9 micromol/L; 6.0-11.8) (p=0.005). The prevalence of moderate hyperhomocyst(e)inemia, defined as the top 90th percentile in controls (13.2 micromol/L), was higher in patients than in controls (23.9% vs. 10.2%, p=0.001). Plasma homocyst(e)ine levels were not correlated to age, body mass index, levels of serum cholesterol, creatinine, and uric acid. Based on multiple logistic regression analyses with adjustment for total cholesterol, hypertension, smoking status, diabetes, age, and body mass index, the adjusted odds ratio of moderate hyperhomocyst(e)inemia for coronary artery disease was 1.53 (95% confidence interval: 1.39-1.65, p=0.0001). Moderate hyperhomocyst(e)inemia, diabetes mellitus, and old age were more prevalent in patients with triple-vessel disease than in single- or double-vessel disease (p=0.02). Multiple logistic regression analysis revealed that moderate hyperhomocyst(e)inemia was a significant predictor of triple-vessel disease with odds ratio of 2.78 (95% confidence interval: 1.08-7.10, p=0.02). We conclude that moderate hyperhomocyst(e)inemia is an independent risk factor for coronary artery disease, and also related significantly to the presence of triple-vessel disease.

A study of the effect of suction drainage on microvascular anastomosis

The effect of suction drainage on the patency of microvascular anastomosis was evaluated in 20 rats. No anastomosed vessels were sucked into the suction drain. Histologic examination of the specimens showed normal healing of the endothelium across the anastomotic site and no evidence of thrombus formation. The results indicate that the suction pressure does not affect the patency of microvascular anastomosis.

Relation of plasma homocyst(e)ine to cerebral infarction and cerebral atherosclerosis

BACKGROUND AND PURPOSE

A number of investigations support the theory that the elevated plasma homocyst(e)ine is associated with occlusive vascular disease. The aim of this study is to examine whether moderate hyperhomocyst(e)inemia is an independent risk factor for cerebral infarction. In addition, we examined the association between plasma homocyst(e)ine and the severity of cerebral atherosclerosis.

METHODS

We conducted a hospital-based case-control study with 140 male controls and 78 male patients with nonfatal cerebral infarction, aged between 39 and 82 years. Plasma homocyst(e)ine levels were analyzed in 218 subjects. Fifty-five patients were evaluated for cerebral vascular stenosis by MR angiography.

RESULTS

The mean plasma level of homocyst(e)ine was higher in cases than in controls (11.8+/-5.6 versus 9.6+/-4.1 micromol/L; P=0.002). The proportion of subjects with moderate hyperhomocyst(e)inemia was significantly higher in cases than in controls (16.7% versus 5.0%; P=0.004). Based on the logistic regression model, the odds ratio of the highest 5% of homocyst(e)ine levels in control group was 4.17 (95% confidence interval, 3.71 to 4. 71)(P=0.0001). After additional adjustment for total cholesterol, hypertension, smoking, diabetes, and age, the odds ratio was 1.70 (95% confidence interval, 1.48 to 1.95) (P=0.0001). The plasma homocyst(e)ine levels of patients having vessels with 3 or 2 stenosed sites were significantly higher than those of patients having vessels with 1 stenosed site or normal vessels (14.6+/-1.4, 11.0+/-1.4 versus 7.8+/-1.5, 8.9+/-1.4 micromol/L respectively; P<0. 02). Multiple logistic regression analysis revealed that moderate hyperhomocyst(e)ienemia was significantly associated with the number of stenosed vessels (P=0.001).

CONCLUSIONS

These findings suggest that moderate hyperhomocyst(e)inemia is an independent risk factor for cerebral infarction and may predict the severity of cerebral atherosclerosis in patients with cerebral infarction.

Molecular analysis of fluoroquinolone-resistance in Escherichia coli on the aspect of gyrase and multiple antibiotic resistance (mar) genes

We analyzed the fluoroquinolone resistance mechanism of 28 isolates of ciprofloxacin-resistant E. coli from patients who received ciprofloxacin as a regimen of a selective gut decontamination. Isolates distinctive by infrequent restriction site polymerase chain reaction (IRS-PCR) were subjected to Hinf I restriction fragment length polymorphism analysis, single-stranded conformation polymorphism (SSCP), and nucleotide sequencing of the quinolone resistance determining region (QRDR) in gyrA. Double mutations in QRDR of gyrA (Ser83 Leu and Asp87Asn) were found from most of the strains. Nucleotide sequencing of the marR locus showed that 18 out of 28 (64%) ciprofloxacin-resistant E. coli strains had three types of base change in marR loci: a double-base change at nucleotides 1628 and 1751, or 1629 and 1751: and a single-base change at 1751. However, all the mutated strains showed no tolerance to cyclohexane test, suggesting the mutation in the marR region had no influence on overexpression of the MarA protein. In conclusion, mutation in gyrA was the main mechanism of ciporfloxacin resistance in E. coli from patients with selective gut decontamination. Therefore, mutation in the mar region did not influence the levels of ciprofloxacin resistance in our isolates.

Radiographic parameters of acetabulum for dysplasia in Korean adults

We analyzed plain radiographs of 591 normal adult hips of various parameters to evaluate the radiological characteristics of the hip joint including the center-edge (CE) angle, acetabular angle, acetabular depth, acetabular roof obliquity and roof angle, and also to verify the rate of acetabular dysplasia. The CE angle was negatively correlated with acetabular angle and acetabular obliquity, but it was positively correlated with acetabular depth and roof angle. The rate of acetabular dysplasia (CE angle < 20 degrees) was 1.8%. We concluded that the CE angle and acetabular angle are more useful parameters for the diagnosis of acetabular dysplasia because there was no significant difference with advancing age and gender, as well as relatively small standard deviations.

Late dissociation of the polyethylene liner from a modular acetabular metal shell after primary total hip arthroplasty--a report of five cases

Modular designs of hip prostheses have become popular recently. Along with complications inherent in all hip arthroplasty systems, modular systems have the additional potential for dissociation of components. Five male patients underwent total hip arthroplasties, in which all of the acetabular components were Harris-Galante II porous acetabular cups. Many years after the operation, the polyethylene liners were dissociated without any previous trauma or dislocation of the femoral heads, these dissociations and dislodgements were managed with open reduction. This complication can be predicted from clinical symptoms and signs. Roentgenograms must be taken and carefully compared to previous roentgenograms. We postulated two causes for the dissociation. First, the polyethylene liner was not fixed securely within the acetabular metal shell at the time of operation. Second, the locking mechanism of the acetabular metal shell was not strong enough to firmly hold the polyethylene liner within the acetabular metal shell. It does warrant that certain precautions must be taken when implanting modular components. The locking mechanism of the harris-Galante II porous acetabular component is mechanically weak and fails easily, therefore its design must be improved in an attempt to prevent postoperative dissociation of the polyethylene liner.

Internal jugular vein thrombosis following modified neck dissection: implications for head and neck flap reconstruction

BACKGROUND

The incidence of internal jugular vein thrombosis (IJVT) following a modified neck dissection remains uncertain. The effect of, or consequences following, IJVT upon pedicled and free flap head and neck reconstructions remains unexplored.

METHODS

Twenty-nine preserved internal jugular veins in 24 patients undergoing modified neck dissection were available for prospective study. All patients required a pedicled or free flap reconstruction and received a modified, unilateral or bilateral cervical lymphadenectomy. The patency of all jugular veins was determined preoperatively and postoperatively using a combination of computed tomography (CT) scanning, high-resolution ultrasound, and color-flow Doppler (CFD).

RESULTS

The IJVT rate was 14%. The presence of a pedicled myocutaneous flap and left-sided jugular dissections may represent risks to the postoperative patency of the internal jugular vein. Preoperative radiotherapy did not appear to impact negatively upon the thrombosis rate.

CONCLUSIONS

Thrombosis of the internal jugular vein may result in significant morbidity for the postoperative oncologic patient. An internal jugular-dependent-free-tissue transfer may risk venous compromise of the flap, whereas the use of a pedicled flap may place the jugular at increased risk for thrombosis. Strategies for deep venous system microvascular recipient recruitment in the head and neck are discussed. Wherever possible, we employ two deep venous systems, the internal jugular, and subclavian (via the external jugular) for flap drainage.

Conservative therapy of adnexal torsion employing color Doppler sonography

STUDY OBJECTIVE

To ascertain if color Doppler sonography (CDS) can detect viability of adnexa in torsion.

DESIGN

Concurrent, nonrandomized study (Canadian Task Force classification II-2).

SETTING

Tertiary medical care center in a university hospital.

PATIENTS

Twenty-seven women suspected of having torsion of the ovary in which a benign tumor was present.

INTERVENTIONS

Color Doppler sonography of the ovarian pedicle suggested torsion. Laparoscopy or laparotomy was performed in 19 patients and confirmed the diagnosis.

MEASUREMENTS AND MAIN RESULTS

We identified a twisted vascular pedicle of the ovarian tumor by CDS in 24 (88%) of 27 women. Pedicle arterial and venous blood flow was observed in 10 women; pathology specimens revealed normal tissue, edema with congestion, or early hemorrhage. In all nine in whom only arterial blood flow or no blood flow was observed, pathology revealed hemorrhagic necrosis. In five women with arterial and venous blood flow the tumor was managed conservatively, either by detorsion or cystectomy, after which no embolism or tumor recurrence was seen at follow-up ultrasonography. Normal follicular development and ovulation occurred in these patients.

CONCLUSION

For women of childbearing age in whom torsion of benign adnexal tumors is suspected, CDS should be performed to confirm the diagnosis and ascertain whether or not pedicle arterial and venous blood flow is present. If such blood flow is detected, the adnexa is considered to be viable and detorsion or cystectomy may be performed, thus preserving the ovary. It is recommended that further studies with a larger group be undertaken to provide a basis for statistical analysis.

Investigation of certain diffraction effects in an optical disk

We report certain diffraction effects that are pertinent to the operation of double-layer optical recording media. For simulating cross-talk effects for double layers, the diffraction of light from the out-of-focus layer and the resulting distribution on the in-focus layer are studied by use of computer simulations. The findings are then verified qualitatively by direct measurements. We also describe a technique for analyzing (by computer simulation) the focus-error signal (FES), taking into account the cross talk between two layers, in systems that use the astigmatic method in conjunction with the double-layer disk. The results of our computer simulations of the FES give us a 10% cross-talk contribution to the original signal. The results of the FES evaluation are compared with those measured in an actual disk drive; good agreement between computation and measurement is obtained.

Molecular epidemiological analysis of quinolone-resistant Escherichia coli causing bacteremia in neutropenic patients with leukemia in Korea

We analyzed an outbreak of Escherichia coli bacteremia in eight patients with leukemia in a hematology-oncology unit from July to September 1994. The antibiograms and genotypic patterns of the isolates were different, thus suggesting that the outbreak did not originate from a single clone. However, all the isolates were resistant to quinolones, which led us to examine the microbiological records from 1992 to 1994. The incidence of quinolone-resistant E. coli bacteremia in the hematology-oncology unit ranged from 81.8% to 94.6% during this period. We then analyzed 36 more isolates recovered from late 1994 to 1995. Field inversion gel electrophoresis patterns of these isolates were also different. Analysis of the quinolone resistance determining region in gyrA revealed that all the isolates had a double mutation in gyrA. In conclusion, quinolone-resistant E. coli could be an emerging threat to neutropenic patients with leukemia who receive a quinolone prophylactically, and attention must be paid to this trend of resistance.

Photoaffinity labeling of the ATP transporter of rat liver microsomes

A photoreactive azido derivative of ATP, 3 (2')-O-(p-azidobenzoyl)-ATP (AB-ATP), was synthesized by the reaction of ATP with N-hydroxysuccinimidyl-4-azidobenzoate (NHS-AB) to photolabel the ATP transporter of rat liver microsomes. AB-ATP specifically inhibited the transport of ATP into microsomes, which indicates that AB-ATP has a high affinity for the ATP transporter, so it can be utilized as a photoaffinity probe for the identification of the ATP transporter in rat liver microsomes. An SDS-polyacrylamide gel electrophoresis (SDS-PAGE) analysis of microsomes photolabeled with [gamma-32P]AB-ATP indicates the presence of four major protein bands with apparent molecular sizes of 97, 56, 53, and 47 kDa. Among these labeled proteins, the 56 kDa protein was completely protected from the photoaffinity labeling by 30 microM ATP but not by the same amount of GTP, which is consistent with the specific labeling of the ATP binding site of the ATP transporter. The specific labeling of the only 56 kDa protein among them was sensitive to the anion transport inhibitor, 4,4'-diisothiocyano-2,2'-disulfonic acid stilbene (DIDS) but not sensitive to the mitochondrial ADP/ATP carrier inhibitor, atractyloside (ATR). Moreover, the 56 kDa protein was uniquely photolabeled with [gamma-32P]AB-ATP in the highly purified rough endoplasmic reticulum (RER) vesicles. These results strongly suggested that the 56 kDa protein represents the ATP transporter of rat liver endoplasmic reticulum (ER).

Esophageal aspergillosis after bone marrow transplant

The prolonged immune suppression associated with bone marrow transplants predisposes to fungal infections including Aspergillus. Disseminated aspergillosis occurs in up to 60% of patients with invasive pulmonary aspergillosis; sites of involvement include the brain, gastrointestinal tract, kidney, liver, thyroid, heart, and spleen. There is only one report of isolated esophageal aspergillosis. A recent acute myelogenous leukemia patient had isolated esophageal aspergillosis after bone marrow transplantation which was successfully treated with amphotericin B.

The factors related to recurrence after transcatheter arterial embolization for the treatment of hemoptysis

OBJECTIVES

Massive hemoptysis is a major clinical problem associated with high morbidity and mortality. Transcatheter arterial embolization is widely used for the treatment of massive hemoptysis, but it was reported that the recurrence rate after embolization is 12-54% in the previous studies. We evaluated the therapeutic effect of transcatheter arterial embolization for the treatment of massive hemoptysis and the factors related to recurrence.

METHODS

We reviewed 51 patients (M:F = 36:15) of transcatheter arterial embolization for the treatment of massive hemoptysis from Jan 1988 to Dec 1994, retrospectively.

RESULTS

After arterial embolization, immediate successful control (< 1 wk) of massive hempotysis was achieved in 48 of 51 patients (94.1%) and recurrence of hemoptysis was observed in 17 of 51 patients (33.3%) during the follow-up period. The patients with non-bronchial artery hemoptysis and multiple artery bleeding had increased tendency of recurrence (77.7%). On the previous history of hemoptysis, the patients with massive hemoptysis (> 400 ml/24hr) or frequent history of hemoptysis had increased tendency of recurrence (87.5%, 72.7%).

CONCLUSION

Transcatheter arterial embolization is a useful and safe procedure for immediate control in massive hemoptysis. However, the patients with this procedure had a potentiality for recurrence. We suggest that close follow-up and caution will be needed in the patients with multiple artery bleeding or with large amounts of hemoptysis or with previous episodes more than 3 times.

Pre-emptive ganciclovir treatment can play a role in restoration of hematopoiesis after allogeneic bone marrow transplantation

We performed pre-emptive ganciclovir therapy on two allogeneic bone marrow transplant (BMT) recipients with myelosuppression associated with cytomegalovirus (CMV) antigenemia after successful engraftment. During the hypoplastic phase, the nucleated cells in the bone marrow and peripheral blood were revealed to be of donor origin by DNA fingerprinting. These two patients had CMV antigen in their peripheral leukocytes. Following the pre-emptive ganciclovir treatment, both of them showed gradual recovery of granulocytes and platelets. They are still alive with stable bone marrow function. From these results, we suppose that infection or reactivation of CMV can suppress bone marrow function after bone marrow transplantation, and the pre-emptive ganciclovir therapy based on the CMV antigenemia may be beneficial if bone marrow function deteriorates after engraftment.

Arthroscopic one-piece excision technique for the treatment of symptomatic lateral discoid meniscus

We introduce a new arthroscopic technique for the partial excision of the symptomatic lateral discoid meniscus in one piece. Our experience indicates that this technique has several advantages compared with the conventional surgical techniques of partial meniscectomy. The operating time is short (less than 20 minutes), it is less aggressive, there is less damage to the cartilage, and less formation of foreign bodies.

Radiographic comparison of osseous healing after maxillary sinusotomy performed with and without a periosteal pedicle

OBJECTIVE

To assess the postoperative fate of bone trapdoors in patients with a trapdoor in the facial wall of the maxillary sinus that was replaced after removal of sinus disease.

STUDY DESIGN

Twenty patients were studied. In 10 patients (group A) the trapdoor was made as a free bone graft; in the other 10 patients (group B), an osteoperiosteal trapdoor was made. The postoperative fate of bone trapdoors was studied by means of computed tomography.

RESULTS

In group A there was poor bony consolidation at the trapdoors' junction with the surrounding bone and a significantly reduced density of the osteotomized bone. In two of the group A patients there was a partial loss of the trapdoor. In group B, however, bony consolidation took place in that all the trapdoors were completely connected again to the surrounding bone and there was no reduction of the bone density.

CONCLUSION

The results indicate that a trapdoor with a periosteal pedicle appears to be more reliable than one without a periosteal pedicle.