Broström ankle ligament repair augmented with suture tape : Results of magnetic resonance imaging evaluation

BACKGROUND

The Broström procedure is an established procedure in cases of primary lateral ankle ligament repair (LALR). To improve postoperative stability an augmentation device, InternalBrace™ (Arthrex, Naples, FL) has been introduced. This study evaluates remodelling of the anterior talofibular ligament (ATFL) in patients undergoing a tape augmented Broström technique as well as clinical outcomes.

METHODS

In this study 32 patients with chronic lateral ankle instability (CLAI) receiving augmented LALR were included. Clinical outcomes were evaluated at a one-time postoperative visit between 12 and 18 months. A 3 T magnetic resonance imaging (MRI) was done to evaluate the morphology of the ATFL. Statistical analysis was completed with the free software and environment R version 3.6.3 (Bell Laboratories, Murray Hill, NJ, USA) and P-values < 0.05 were considered statistically significant.

RESULTS

The mean follow-up time was 15.3 ± 1.8 months with a return to sport time of 4.0 ± 2.4 months. The average AOFAS (American Orthopaedic Foot and Ankle Society Score) score was 94.4 ± 7.2, the FAOS (Foot and Ankle Outcome Score) demonstrated 87.3 ± 10.4 points and the FFI (Foot Function Index - 2 scores (pain and function score)) was 22.9 ± 20.1 and 15.4 ± 10.4, respectively. The MRI findings demonstrated an average length of the ATFL of 18.6 ± 4.3 mm and the width was 3.6 ± 0.9 mm. A clear differentiation between the ATFL and the augmentation device could be shown in 28 cases. The Fisher's exact test could not depict a significant correlation between the presence of a bone marrow edema and the tension of the augmentation device with a level of significance of α = 0.05.

CONCLUSION

An anatomical healing tendency of the ligament repair and good integrity of the augmentation device could be shown based on MRI findings. The lateral ligament repair augmented with suture tape is an effective and safe procedure regarding surgical treatment in chronic lateral ankle instability producing good clinical outcome.

Influence of Scan Parameters of Single and Dual-Energy CT Protocols in Combination with Metal Artifact Suppression Algorithms for THA: An ex Vivo Study

BACKGROUND

Metal artifacts caused by hip arthroplasty stems limit the diagnostic value of computed tomography (CT) in the evaluation of periprosthetic fractures or implant loosening. The aim of this ex vivo study was to evaluate the influence of different scan parameters and metal artifact algorithms on image quality in the presence of hip stems.

METHODS

Nine femoral stems, 6 uncemented and 3 cemented, that had been implanted in subjects during their lifetimes were exarticulated and investigated after death and anatomical body donation. Twelve CT protocols consisting of single-energy (SE) and single-source consecutive dual-energy (DE) scans with and without an iterative metal artifact reduction algorithm (iMAR; Siemens Healthineers) and/or monoenergetic reconstructions were compared. Streak and blooming artifacts as well as subjective image quality were evaluated for each protocol.

RESULTS

Metal artifact reduction with iMAR significantly reduced the streak artifacts in all investigated protocols (p = 0.001 to 0.01). The best subjective image quality was observed for the SE protocol with a tin filter and iMAR. The least streak artifacts were observed for monoenergetic reconstructions of 110, 160, and 190 keV with iMAR (standard deviation of the Hounsfield units: 151.1, 143.7, 144.4) as well as the SE protocol with a tin filter and iMAR (163.5). The smallest virtual growth was seen for the SE with a tin filter and without iMAR (4.40 mm) and the monoenergetic reconstruction of 190 keV without iMAR (4.67 mm).

CONCLUSIONS

This study strongly suggests that metal artifact reduction algorithms (e.g., iMAR) should be used in clinical practice for imaging of the bone-implant interface of prostheses with either an uncemented or cemented femoral stem. Among the iMAR protocols, the SE protocol with 140 kV and a tin filter produced the best subjective image quality. Furthermore, this protocol and DE monoenergetic reconstructions of 160 and 190 keV with iMAR achieved the lowest levels of streak and blooming artifacts.

LEVEL OF EVIDENCE

Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

The impact of antihyperlipidemic drugs on the viral load of patients with chronic hepatitis C infection: a meta-analysis

Several studies investigating the role of statins and fibrates in chronic hepatitis C virus (HCV) infection offered so far conflicting evidence regarding the antiviral potency of these medications, whereas combination of these drugs with pegylated interferon and ribavirin improved in some trials therapeutic outcome. We conducted a literature search to identify trials that included monoinfected HCV patients, treated with statins or fibrates as monotherapy with the primary end point of our meta-analysis being the quantitative change of HCV-RNA induced by these medications. Logarithmic changes of the viral load (ΔlogVL) and confidence intervals (CIs) were calculated according to the DerSimonian-Laird estimate. Statistical heterogeneity was assessed with the I² statistic. We identified eight observational studies that evaluated the potency of bezafibrate and different statins as monotherapy to induce a significant reduction of HCV-RNA in HCV-monoinfected patients (n = 281). Overall, a significant reduction of viral load with mean 0.19 [log10 IU/mL] (95%-confidence interval, (CI) 0.11-0.28) could be observed when antihyperlipidemic medications were administered. Bezafibrate featured the highest antiviral efficacy (0.45 log10 reduction, 95%-CI, 0.17-0.72) among all medications and fluvastatin (0.20 log10 reduction, 95%-CI, 0.09-0.31) among all statins tested. Based on meta-analysis, fibrates and statins induce a reduction of HCV viral load. We suggest that the addition of statins and fibrates to antiviral regimes, especially in HCV patients with concomitant dyslipidemia, could beside the established reduction of cardiovascular risk increase the potency of antiviral therapy.

A randomized controlled trial adding fluvastatin to peginterferon and ribavirin for naïve genotype 1 hepatitis C patients

Fluvastatin or simvastatin has demonstrable antiviral activity against hepatitis C virus (HCV) as monotherapy. The safety and efficacy of adding fluvastatin or simvastatin to peginterferon/ribavirin for 48 weeks was tested in HCV genotype 1 naïve-to-treatment veterans. Thirty-seven naïve-to-treatment genotype 1 HCV patients were randomized to either a control group (n = 20) to receive peginterferon alfa plus ribavirin or an experimental group (n = 18) to similarly receive peginterferon alfa plus ribavirin as well as fluvastatin 20 mg/day. In addition, seven patients who presented for HCV treatment already were on simvastatin and could not be withdrawn. These simvastatin users were not randomized but were entered into a concurrent prospective pilot arm. There were no unique safety issues with fluvastatin or simvastatin when these drugs were given with peginterferon/ribavirin for 48 weeks. Thirteen of 25 statin patients achieved sustained viral response (SVR), while 5 of 20 control patients achieved SVR. Analysis of SVR by intention-to-treat showed P = 0.078. In this phase 2 study, there were no safety issues with the addition of fluvastatin or simvastatin to peginterferon and ribavirin for 48 weeks. There was a trend towards improvement in SVR when fluvastatin or simvastatin was administered with peginterferon/ribavirin. The size of the groups did not reach the prestudy size thought needed to show significant difference (type II error). These results support the significant results of two other larger randomized controlled trials reported using the same dose of fluvastatin in naïve-to-treatment genotype 1 HCV patients.

Health care reform in the USA: Recommendations from USA and non-USA radiologists

AIM: To compare the opinions and recommendations of imaging specialists from United States (USA) and non-USA developed nations for USA health care reform.

METHODS: A survey was emailed out to 18 imaging specialists from 17 non-USA developed nation countries and 14 radiologists within the USA regarding health care reform. The questionnaire contained the following questions: what are the strengths of your health care system, what problems are present in your nation’s health care system, and what recommendations do you have for health care reform in the USA. USA and non-USA radiologists received the same questionnaire.

RESULTS: Strengths of the USA health care system include high quality care, autonomy, and access to timely care. Twelve of 14 (86%) USA radiologists identified medicolegal action as a major problem in their health care system and felt that medicolegal reform was a critical aspect of health care reform. None of the non-USA radiologists identified medicolegal aspects as a problem in their own country nor identified it as a subject for USA health care reform. Eleven of 14 (79%) USA radiologists and 16/18 (89%) non-USA radiologists identified universal health care coverage as an important recommendation for reform.

CONCLUSION: Without full universal coverage, meaningful health care reform will likely require medicolegal reform as an early and important aspect of improved and efficient health care.

Treatment of Hemodialysis-Associated Adynamic Bone Disease with Teriparatide (PTH1-34): A Pilot Study

BACKGROUND

Adynamic bone disease (ABD) is caused by a relative or absolute parathyroid hormone (PTH) deficiency. Teriparatide (PTH1-34) is an osteoanabolic agent in clinical use. Here, it was hypothesized that treatment with teriparatide improves bone mineral density (BMD) of ABD patients.

PATIENTS AND METHODS

Seven hemodialysis patients with ABD and a median iPTH level of 22 pg/ml were evaluated in this open-label, prospective, 6-month observational pilot-study. All patients received 20 μg teriparatide/day subcutaneously. Serologic bone markers, BMD and coronary artery calcification (CAC) were measured at baseline and after 6 months.

RESULTS

Teriparatide therapy led to a significant increase in lumbar spine (0.885 ± 0.08 vs. 0.914 ± 0.09 g/cm(2), p < 0.02), but not femoral neck (0.666 ± 0.170 vs. 0.710 ± 0.189 g/cm(2), p = 0.18) BMD. Compared to pretreatment values, calculated monthly changes in BMD improved significantly in both the lumbar spine and femoral neck (p < 0.02). Changes in serologic markers of bone turnover and CAC scores were not statistically significant.

CONCLUSION

Teriparatide therapy might improve low BMD in hemodialysis patients with ABD. Further clinical studies are needed to establish teriparatide as a therapeutic option for dialysis patients with ABD.

Masitinib, a c-kit/PDGF receptor tyrosine kinase inhibitor, improves disease control in severe corticosteroid-dependent asthmatics

BACKGROUND

Masitinib is a tyrosine kinase inhibitor targeting stem cell factor receptor (c-kit) and platelet-derived growth factor (PDGF) receptor, which are expressed on several cell types including mast cells and bronchial structural cells, respectively. We hypothesized that c-kit and PDGF receptor inhibition may decrease bronchial inflammation and interfere with airway remodeling, which are crucial features of severe asthma.

OBJECTIVES

The primary endpoint was the percent change from baseline in oral corticosteroids after 16 weeks of treatment. Change in asthma control (asthma control questionnaire), exacerbation rate, pulmonary function tests, rescue medication requirement and safety were secondary endpoints.

METHODS

A 16-week randomized, dose-ranging (3, 4.5, and 6 mg/kg/day), placebo-controlled study was undertaken in 44 patients with severe corticosteroid-dependent asthma who remained poorly controlled despite optimal asthma management.

RESULTS

At 16 weeks of treatment, a comparable reduction in oral corticosteroids was achieved with masitinib and placebo (median reduction of -78% and -57% in the masitinib and placebo arms, respectively). Despite this similar reduction, the Asthma Control Questionnaire score was significantly better in the masitinib arm as compared to placebo with a reduction by 0.99 unit at week 16 (P < 0.001) vs 0.43 unit in the placebo arm. Masitinib therapy was associated with more transient skin rash and edema.

CONCLUSIONS

Masitinib, a c-kit and PDGF-receptor tyrosine kinase inhibitor, may represent an innovative avenue of treatment in corticosteroid-dependent asthma. These preliminary results warrant further long-term clinical studies in severe asthma

Atrial function after ablation procedure in patients with chronic atrial fibrillation using steady-state free precession magnetic resonance imaging

BACKGROUND

Surgical ablation procedures are an established surgical procedure for restoration of sinus rhythm and reestablishment of atrial function in patients with chronic atrial fibrillation. The purpose of this study was to evaluate the feasibility and reproducibility of steady-state free precession magnetic resonance imaging (SSFP MRI) for examination of atrial dimensions and function after ablation procedures.

METHODS

Nineteen patients (mean age, 63.1 +/- 11.7 years) being at least six months after surgical ablation procedure, with stable sinus rhythm, were selected for the study. They underwent cardiac MRI. End-diastolic and end-systolic volumes were measured using Simpson's rule. The presence of visual contraction was visually assessed.

RESULTS

In MRI evaluation mean end-diastolic volume of the right atrium and left atrium after an ablation procedure was 127 +/- 45 mL and 163 +/- 50 mL, respectively. Mean stroke volume was 23 +/- 15 mL and 26 +/- 12 mL for the right and left atrium. Mean ejection fraction of the right atrium was 0.19 +/- 0.14 and 0.17 +/- 0.1 for the left atrium. An atrial kick of both atria was observed in 8 of 19 (47%) patients. An atrial kick of only the right atrium was observed in an additional 13 of 19 (68%) patients.

CONCLUSIONS

The anticipated events after a surgical ablation procedure are the restoration of atrial contractility and the associated atrial kick, thereby enhancing cardiac output and decreasing the risk of thromboembolism. Evaluation of atrial function after an ablation procedure using SSFP MRI is feasible and allows a standardized documentation of postoperative atrial function, thus allowing evaluation of the surgical outcome in a reproducible way. Echocardiographic evaluation seems to underestimate the transport function of the atrium.

Incidence of chronic knee lesions in long-distance runners based on training level: Findings at MRI

PURPOSE

The purpose of this study was to evaluate the incidence of chronic knee changes in long-distance runners based on the training status, including distance, running frequency, training pace, and running experience.

METHODS

MRI of the knee was performed in 26 non-professional runners 5 days after their last training unit. Lesions of the menisci and cartilage (5-point scale), bone marrow and ligaments (3-point scale), and joint effusion were evaluated. A total score comprising all knee lesions in each runner was evaluated. The incidence of the knee changes was correlated with the training level, gender, and age of the runners.

RESULTS

Grade 1 lesions of the menisci were found in six runners with a high training level, and in only four runners with a low training level. Grade 1 cartilage lesions were found in three high-trained runners and in one low-trained runner, and grade 2 lesions were found in one high-trained runner and in two low-trained runners, respectively. Grade 1 anterior cruciate ligament lesions were seen in three runners with a high- and in two runners with a low-training level. Runners with a higher training level showed a statistically significant higher score for all chronic knee lesions than those with a lower training level (p<0.05).

CONCLUSIONS

MRI findings indicate that a higher training level in long-distance runners is a risk factor for chronic knee lesions.

Liver transplantation for hepatitis B in the United States

AIM

To evaluate the impact of hepatitis B virus (HBV) on US health care system, we reviewed the Organ Procurement and Transplantation (OPTN, formerly UNOS) HBV database.

METHOD

We reviewed records of liver transplantations (LTx) performed in the United States listed for the diagnoses of HBV between 1993 and mid-October 2004. Both acute as well as chronic cases were included. Coinfection with hepatitis C virus was excluded from study. The specific states selected for review were chosen from those areas that are receiving large numbers of new immigrants from high HBV endemic areas (ie, Texas, Pennsylvania, California, New York, and Florida). One-, 3-, and 5-year patient survival rates for both cadaveric and living related donors were analyzed. Survival rates were obtained from OPTN database as Kaplan-Meyer survival test.

RESULTS

Between 1993 and mid-October 2004, 53,312 LTx had been performed nationwide. Of these, 2314 (4.34%) were performed for the diagnosis of HBV; 1816 cases (78%) were due to chronic HBV infection (45 of them were living donor LTx) and 498 cases (22%) were due to HBV-induced acute liver failure (seven of them were living donor LTx). Three- and 5-year survival rates of chronic HBV-related LTx patients were better than acute HBV-related and overall LTx patients.

CONCLUSION

HBV is generally considered to have a minor health significance by many community gastroenterologists. With growing immigration from overseas, it may eventually have a higher impact on LTx. Therefore, it is crucial to further educate gastroenterologists and primary care physicians caring for this specific group of patients.

Total Endoscopic CABG Using Robotics on Beating Heart

BACKGROUND

The implementation of a total endoscopic coronary surgery on the beating heart with the aid of the Da Vinci surgical system (Intuitive, Sunnyvale, CA) requires a stepwise learning process. After cadaveric training and clinical start of the program in November 2002, we gained experience with arrested heart procedures starting in May 2003. In November 2003, we moved to beating heart surgery.

METHODS

From November 2003 to January 2005, 14 patients with coronary artery disease (mean age of 62 +/- 5 years, female to male ratio 2:12) were operated with the intention to perform a beating heart TECAB (totally endoscopic coronary artery bypass grafting) procedure.

RESULTS

Total conversion rate was 35% (5/14), due to pleural adhesions in 2 patients, injury of the lung during port placement, inability to occlude the LAD with saddle loops, atherosclerotic diseased mammary artery in 1 patient each. Mean operating time was 298 +/- 110 minutes with a steady decline throughout the study period (first 5 patients: 342 +/- 61 minutes, patients 6 to 9: 337 +/- 87 minutes, last 4 patients: 290 +/- 53 minutes), resulting in a 60 minute shorter operating time. Mean ICU stay was 1.3 days and hospital stay lasted on average 8.4 +/- 2.8 days.

CONCLUSION

Total endoscopic bypass surgery on the beating heart with the Da Vinci surgical system can be safely implemented in clinical use. The learning curve results in a constantly decreasing procedure time due to a more effective table team-console surgeon-robotic system interaction and a moderate conversion rate.

Hypothalamic regulation of adiposity: the role of 11beta-hydroxysteroid dehydrogenase type 1

Following extensive suprasellar operations for excision of hypothalamic tumors, some patients develop morbid obesity despite receiving replacement doses of glucocorticoids. Urine analysis of cortisol and cortisone metabolites show that 11-OH/11-oxo ratios are significantly higher in patients with hypothalamic obesity, indicating enhanced 11beta-HSD1 activity. This correlates with the visceral-to-subcutaneous fat ratio. The consequence of increased 11beta-HSD1 activity and a shift of the steroid inter-conversion towards cortisol may contribute to the effects of the latter in adipose tissue. The message from the hypothalamus to adipocyte 11beta-HSD-1 involves hormones, the sympathetic nervous system and cytokines. CRH and ACTH downregulate 11beta-HSD-1 activity and induce lipolysis. Tumor necrosis factor-alpha and interleukin-1beta upregulate 11beta-HSD-1 expression and activity, while enhancing lipolysis. The sympathetic nervous system exerts its effects through beta-adrenergic upregulation and alpha-adrenergic downregulation of 11beta-HSD-1 activity. Inhibition of 11beta-HSD-1 suppresses preadipocyte differentiation into mature adipocytes, and may provide a therapeutic tool.

Spontaneous rupture of liver in a non-pregnant patient: case report

Spontaneous rupture of the liver during pregnancy associated with preeclampsia is an uncommon and frequently fatal complication. A case of a 61-year-old non-pregnant female is described here who took estrogen replacement for 16 years and presented with spontaneous rupture of the right lobe of the liver with hemoperitoneum. The underlying cause of the rupture was not clear.

Human adipose tissue under in vitro inhibition of 11beta-hydroxysteroid dehydrogenase type 1: differentiation and metabolism changes

In humans, oxoreducing 11beta-HSD-1 activity appears to be related to body fat distribution in male-type central obesity, but not in female-type peripheral obesity. We postulated that inhibition of 11beta-HSD-1 might have clinical therapeutic significance in oxoreducing mostly visceral fat and its metabolic activity. Our current study investigated the consequence at the cellular level of such inhibition. As an inhibitor of 11beta-HSD-1 activity, we used the licorice derivative carbenoxolone. Carbenoxolone has an inhibitory effect on the activity of both oxidizing 11beta-HSD-2, which converts cortisol to cortisone, and oxoreducing 11beta-HSD-1; yet, preadipocytes and adipocytes only express the latter. Preadipocytes were retrieved from omental and subcutaneous fat from healthy non-obese individuals and differentiated in vitro to mature adipocytes. Activity of 11beta-HSD-1 was assayed by measuring conversion of added 500 nM cortisone to cortisol. Expression of 11beta-HSD-1 mRNA was determined by real-time PCR, while lipolytic effects were determined by measuring glycerol and triglyceride concentration in the culture medium. Carbenoxolone decreased 11beta-HSD-1 activity in a dose-dependent manner with an IC-50 of 5X10 -6 M, but did not affect the expression of 11beta-HSD-1 mRNA. Cortisone stimulated subcutaneous, but not omental preadipocytes proliferation, an effect that was not abolished by carbenoxolone. Dexamethasone had a stimulatory effect on the maturation of both omental and subcutaneous preadipocytes. Carbenoxolone per se, either with or without cortisone, had a negative effect on preadipocyte maturation. Inhibiting 11beta-HSD-1 activity by carbenoxolone had no impact on leptin secretion. Thus, carbenoxolone has no effect on preadipocyte proliferation, but a dramatic inhibitory effect on preadipocyte differentiation into mature adipocytes. The mechanism is only partly related to its inhibitory effect on 11beta-HSD-1 activity. The present observations lend support to the presence of an intracrine loop of a hormone that is both produced from a precursor and active within the preadipocyte and adipocyte.

HIV type 1 Tat inhibits tumor necrosis factor alpha-induced repression of tumor necrosis factor receptor p55 and amplifies tumor necrosis factor alpha activity in stably tat-transfected HeLa Cells

The human immunodeficiency virus type 1 (HIV-1) Tat protein is a key regulatory protein in the HIV-1 replication cycle. Tat interacts with cellular transcriptional factors and cytokines, such as tumor necrosis factor (TNF-alpha), and alters the expression of a variety of genes in HIV-1-infected and noninfected cells. To further elucidate the mechanisms by which HIV-1 Tat amplifies the activity of TNF-alpha, we transfected the HIV-1 tat gene into an epithelial (HeLa) cell line. We observed that Tat-expressing cells had increased NF-kappa B-dependent trans-activational activity due to enhanced NF-kappa B--DNA binding in response to TNF-alpha treatment. Tumor necrosis factor receptor (TNFR) p55 was the prominent receptor, as neutralizing antibodies to TNFR p55, but not to TNFR p75, blocked TNF-alpha-mediated NF-kappa B activation. Furthermore, tat-transfected cells were more sensitive to TNF-alpha-induced cytotoxicity and only the neutralizing antibodies to TNFR p55 completely protected the cells. To determine whether TNFR p55 was involved in amplification of cellular response to TNF-alpha by HIV-1 Tat, we investigated the effect of TNF-alpha on TNFR p55 expression in the tat-transfected cells. TNF-alpha treatment resulted in a reduction in both TNFR p55 mRNA and protein levels in the control cells but not in the tat-transfected cells as determined with Northern blot and Western blot analyses, respectively. Our results indicate that HIV-1 Tat may inhibit TNF-alpha-induced repression of TNFR p55 and thereby amplify TNF-alpha activity in these stably transfected cells.

Perturbation of the tight junction permeability barrier by occludin loop peptides activates beta-catenin/TCF/LEF-mediated transcription

Here we show that interference with the integrity of the transepithelial permeability barrier of mouse mammary epithelial cells by treatment with synthetic peptides, homologous to the second extracellular domain of occludin, decreased the amount of occludin protein present at tight junctions and led to the formation of multilayered, unpolarized cell clusters. In addition, transcription of the adherens junction protein beta-catenin was induced. Following accumulation of soluble beta-catenin protein, transcription by beta-catenin/TCF/LEF was increased, as revealed by transcriptional assays following transient transfection of the reporter construct. Furthermore, treatment with occludin-II peptides up-regulated RNA levels of the known beta-catenin/TCF/LEF downstream target gene c-myc. The data presented imply a functional cross-talk between tight and adherens junctions that possibly contributes to the stepwise transformation during oncogenesis.

Bilaminar pattern of tibial condyle cartilage layer on the fat-suppressed 3D gradient echo images: artifact or structural and biochemical difference in composition of cartilage?

The purpose of this study was to examine if an unusual bilaminar pattern of lateral tibial condyle cartilage layer on the fat-suppressed three-dimensional (3D) spoiled gradient echo sequence is artifactual or correlates with structural and/or biochemical composition of cartilage. The laminar appearance of the lateral tibial condyle cartilage layer was studied on fat-suppressed 3D spoiled gradient echo MR images of the knee joint in 67 patients (mean age: 28y) performed at 1.0 Tesla. After i.v. administration of gadopentetate dimeglumine, diffusion of the contrast media into cartilage layer was qualitatively analysed over time on inversion recovery spin echo images of knee joints of five asymptomatic volunteers (mean age: 25y). In a patient with osteosarcoma and total knee replacement, MR examination of cartilage layer of lateral tibial plateau was compared with histologic specimens stained with Safranin-O, demonstrating proteoglycan distribution in cartilage. The retrospective analysis of 67 knee joints revealed a bilaminar appearance of lateral tibial condyle cartilage layer in the gradient echo images in the majority of cases (81%) with a statistically significant tendency to a trilaminar pattern in patients older than 20 years. With i.v. contrast administration, the contrast enhancement was only observed in the superficial zone of tibial cartilage layer. Histologic specimens in one patient demonstrated a good correlation between thickness of proteoglycan-free and proteoglycan-rich laminae of lateral tibial condyle on Safranin-O staining with hyperintense and hypointense zones, respectively, on corresponding fat-suppressed 3D spoiled gradient echo images (correlation coefficient of 0.87). Bilaminar pattern of tibial condyle cartilage layer on fat-suppressed 3D spoiled gradient echo images in younger subjects is not an artifact or an intrachondral lesion, but it may represent a regional difference in composition of extracellular cartilage matrix possibly produced by a highly-oriented collagen fiber structure associated with a high concentration of proteoglycans in the middle and deep portion of the cartilage layer.

Traumatic pharyngo-oesophageal perforation in the newborn: a condition mimicking oesophageal atresia

Two newborn infants with traumatic perforation of the pharyngo-oesophageal region are presented. This injury was induced by pharyngeal suction catheters and/or vigorous attempts at nasogastric or tracheal intubation during resuscitation of the newborn. The true nature of this condition remained unrecognized and the babies were thus referred with a tentative diagnosis of oesophageal atresia. The perforation itself could be treated successfully without surgery, despite a severe complication in one infant resulting from inadvertent use of barium sulphate contrast medium. Raising awareness of the possibility of this injury should help in avoiding this complication by gentle and skilful action during newborn resuscitation, particularly in the premature infant.

Fetal meconium peritonitis after maternal hepatitis A

Hepatitis A virus has rarely been implicated in congenital infections. After maternal hepatitis A at 13 weeks' gestation, ultrasonographic examinations revealed fetal ascites (20 weeks) and meconium peritonitis (33 weeks). After delivery, a perforated distal ileum was resected. Elevated levels of hepatitis A immunoglobulin G persisted in the infant 6 months after delivery.

[Rheumatic diseases of the ankle joint and tarsus]

Diseases of the hindfoot are associated with considerable functional impairment and therefore may hamper patients' movements during gait considerably. Because of biomechanical overload, articular structures, tendons and ligaments are prone to early degenerative changes during the course of rheumatic diseases as visible with plain film radiography, sonography (US), or magnetic resonance imaging (MRI). Findings may occur as arthritis of major joints or in the form of fibroostitis and bursitis of the os calcis. Despite the progressive course of rheumatic diseases and characteristic imaging findings, high variability of X-ray signs may occur. Plain film radiograms and high-resolution ultrasonography play a key role in imaging rheumatic diseases of the hindfoot. MRI supports imaging diagnosis in selected cases. The principal goals of diagnostic imaging are precise and reproducible documentation of morphologic abnormalities and differentiated analysis for planning proper conservative or surgical treatment.

Role of MutS ATPase activity in MutS,L-dependent block of in vitro strand transfer

In addition to mismatch recognition, Escherichia coli MutS has an associated ATPase activity that is fundamental to repair. Hence, we have characterized two MutS mutant gene products to define the role of ATP hydrolysis in homeologous recombination. These mutants, denoted MutS501 and MutS506, have single point mutations within the Walker A motif, and rate constants for ATP hydrolysis are down 60-100-fold as compared with wild type. Both MutS501 and MutS506 retain mismatch binding and, unlike wild type, fail to relinquish this specificity in the presence of ATP, adenosine 5'-O-(thiotriphosphate), and adenosine 5'-(beta, gamma-imino)triphosphate. Both MutS501 and MutS506 blocked the level of strand transfer between M13 and fd DNAs. The level of inhibition varied between the mutants and corresponded with the relative affinities to a G/T mispair. Neither MutS501 nor MutS506, however, would afford complete block of full-length heteroduplex in the presence of MutL. DNase I footprinting data are consistent with these results, as the region of protection by MutS501 and MutS506 was unchanged in the presence of ATP and MutL. Taken together, these studies suggest that 1) MutS impedes RecA-mediated homeologous exchange as a distinct mismatch-provoked event and 2) the role of MutL is coupled to MutS-dependent ATP hydrolysis. These observations are in good agreement with the present model for E. coli methyl-directed mismatch repair.

Differentiation-dependent regulation of retinal dehydrogenase gene expression in the trachea

Retinoic acid (RA), a metabolite of vitamin A, is known to be a key signaling molecule in regulating epithelial cell differentiation. We recently characterized and cloned a retinal dehydrogenase (RALDH) that catalyzes the oxidation of retinal to RA. In this study, we investigated the effects of retinoids on the level of RALDH mRNA and protein as well as RALDH activity in the trachea and cultured tracheal epithelial cells. Vitamin A deficiency induced squamous metaplasia in the tracheal epithelium and down-regulated RALDH expression. Supplementation of retinol and retinoic acid to vitamin A deficient rats restored the normal mucociliary epithelium and up-regulated the RALDH expression. In rat epithelial cells cultured in vitro, RAinhibited squamous differentiation and promoted mucociliary differentiation. Squamous differentiated cultures (RA-) expressed very low levels of RALDH mRNA, whereas mucociliary differentiated cultures (RA+) expressed high levels of RALDH mRNA. Retinal and retinol were poor inducers of mucociliary differentiation as well as RALDH expression. The RALDH expression paralleled the expression of the mucin-1 gene in mucociliary cultures. These results suggest that the expression of RALDH is dependent on the differentiation state of the airway epithelium.

Tumor necrosis factor alpha stimulates arachidonic acid metabolisms and mucus production in rat tracheal epithelial cell cultures

Air-liquid interface (ALI) cultures of rat tracheal epithelial (RTE) cells were used to study the response of differentiated airway epithelial cells to the inflammatory cytokine, tumor necrosis factor alpha (TNF alpha). We found that the cultures expressed low levels of TNF alpha receptors. TNF alpha stimulated the AA-cascade: cytoplasmic phospholipase A2 (cPLA2) and prostaglandin H synthase 2 (PGHS2) were upregulated; as a result prostaglandin E (PGE2) secretion was increased. Subsequent to the increase in PGE2 mucus secretion increased, suggesting that PGE2 may act as an autocrine regulator of mucus secretion.

Tumor necrosis factor-alpha modulates the expression of its p60 receptor and several cytokines in rat tracheal epithelial cells

The epithelium of the conducting airways is frequently the target of toxic chemical and microbial agents causing inflammation, hypersecretion, and epithelial necrosis. TNF-alpha is a prototypical inflammatory cytokine released by macrophages and other inflammatory cells. The purpose of this study was to characterize TNF-alpha receptors in fully differentiated rat tracheal epithelial (RTE) cells in culture and to examine the effects of TNF-alpha on this epithelium. We demonstrated the presence of approximately 250 TNF-alpha receptors per RTE cell. Both known receptor types, p60 (TNF-RI, CD 120a) and p80 (TNF-RII, CD 120b), were expressed. The level of p80 mRNA was unaffected by TNF-alpha treatment, whereas p60 mRNA was down-regulated, and soluble TNF-RI was shed from cells within 30 min. Treatment of RTE cultures with TNF-alpha (1000 U) caused no cytotoxicity (as determined by lactate dehydrogenase release). However, TNF-alpha exposure of the cultures induced the expression of several inflammatory mediators, as determined by reverse transcription-PCR and ELISA. Low levels of IFN-gamma mRNA became detectable after 4 h. Increased levels of TNF-alpha mRNA and protein were found, which peaked after 6 h of TNF-alpha treatment, but neither IL-1 alpha nor IL-1 beta was detectable. Calcium-independent nitric oxide synthase transcripts were elevated two- to threefold within 2 to 6 h of TNF-alpha treatment. These findings suggest that the airway epithelium may actively participate in the pathogenesis of airway inflammation through the production of mediators similar to those found in a Th1 response.

Torsion of a normal adnexa in a premenarcheal girl: MRI findings

Torsion of the adnexa can be the cause of abdominal pain. An immediate diagnosis is very important because early surgical intervention is the only way to save the ovary from necrosis. Torsion of a normal adnexa is rare, but occurs more frequently than is generally appreciated. If US findings are equivocal, MRI can provide additional information. In our case the MRI findings leading to the diagnosis of ovarian torsion were: (a) A medial ovarian mass existed with dislocation of the uterus to the affected side with hyperintense, cystic lesions on T2-weighted images at the periphery of the ovary. (b) Beaked protrusion of the mass continuing in a band-like structure connecting it with the uterus obviously represented the Fallopian tube. (c) Low and inhomogeneous signal intensity of the stroma on T1- and T2-weighted images and lack of gadolinium uptake were indicative of infarction.

Tumor necrosis factor-alpha modulates the expression of its p60 receptor and several cytokines in rat tracheal epithelial cells

The epithelium of the conducting airways is frequently the target of toxic chemical and microbial agents causing inflammation, hypersecretion, and epithelial necrosis. TNF-alpha is a prototypical inflammatory cytokine released by macrophages and other inflammatory cells. The purpose of this study was to characterize TNF-alpha receptors in fully differentiated rat tracheal epithelial (RTE) cells in culture and to examine the effects of TNF-alpha on this epithelium. We demonstrated the presence of approximately 250 TNF-alpha receptors per RTE cell. Both known receptor types, p60 (TNF-RI, CD 120a) and p80 (TNF-RII, CD 120b), were expressed. The level of p80 mRNA was unaffected by TNF-alpha treatment, whereas p60 mRNA was down-regulated, and soluble TNF-RI was shed from cells within 30 min. Treatment of RTE cultures with TNF-alpha (1000 U) caused no cytotoxicity (as determined by lactate dehydrogenase release). However, TNF-alpha exposure of the cultures induced the expression of several inflammatory mediators, as determined by reverse transcription-PCR and ELISA. Low levels of IFN-gamma mRNA became detectable after 4 h. Increased levels of TNF-alpha mRNA and protein were found, which peaked after 6 h of TNF-alpha treatment, but neither IL-1 alpha nor IL-1 beta was detectable. Calcium-independent nitric oxide synthase transcripts were elevated two- to threefold within 2 to 6 h of TNF-alpha treatment. These findings suggest that the airway epithelium may actively participate in the pathogenesis of airway inflammation through the production of mediators similar to those found in a Th1 response.

Retinoid-induced differentiation regulates prostaglandin H synthase and cPLA2 expression in tracheal epithelium

Rat tracheal epithelial cells cultured in vitro at an air-liquid interface can differentiate into a mucociliary or squamous phenotype depending on the presence or absence of retinoic acid (RA). The airway epithelium is known to produce a number of eicosanoids. We propose that eicosanoid biosynthesis is dependent on the differentiation status of the epithelium. Therefore, prostaglandin production and the expression of cytosolic phospholipase A2 (cPLA2) and the prostaglandin H synthase (PGHS) isoforms were investigated during differentiation to these two phenotypes. The major eicosanoid produced by both phenotypes was prostaglandin E2 (PGE2). Proliferating undifferentiated cultures produced low levels of PGE2 regardless of retinoid status. Differentiated mucociliary cultures produced high levels of PGE2 (50 ng/10(6) cells), whereas differentiated squamous cultures produced low levels of PGE2 (< 5 ng/10(6) cells). Mucociliary cultures expressed high levels of cPLA2 and PGHS-2 isoform mRNA and protein. In contrast squamous cultures expressed very low levels of cPLA2 and PGHS-2 transcript and protein. The PGHS-1 isoform was expressed in squamous but not in mucociliary cultures. We investigated changes in expression of these enzymes during retinoid treatment of established squamous cultures. Treatment with RA resulted in a rapid (24 h) downregulation of PGHS-1 mRNA expression. However, the cPLA2 and PGHS-2 genes were expressed in squamous cultures only after 3 days of RA treatment coincident with redifferentiation of the culture to a mucociliary phenotype. These studies reveal that retinoid-induced differentiation of airway epithelium into either a mucociliary or squamous phenotype results in profound changes in the expression of cPLA2 and PGHS isozymes that regulate prostaglandin formation.

Regulation of MUC5 and MUC1 gene expression: correlation with airway mucous differentiation

The purpose of this paper was to obtain probes to study the structure and function of mucins in rat models of airway cell differentiation and disease. We report the isolation and characterization of the rat cDNA homologue of the human airway secretory mucin, MUC5. Furthermore, we demonstrate the coordinate regulation of the expression of MUC5 and MUC1 (a membrane-bound mucin) and mucous differentiation. The rat MUC5 was cloned by the RT-PCR using motifs conserved in the secretory mucins, MUC2 and MUC5. The rat cDNA revealed a high degree of sequence similarity to human MUC5 (73% at the amino acid level). Alignments with three other secretory mucins (human MUC5, human MUC2, rat MUC2), indicated a conservation of the cysteines and of the octapeptide motifs, but a lack of conservation of a short tandem repeat sequence that is found only in the human MUC5. Northern analysis of MUC1 and MUC5 indicated a specific tissue-restricted pattern of expression. Surprisingly, rat MUC5 exhibited a monodisperse signal, a characteristic that is unusual for most secretory mucins, including the human MUC5. Expression of MUC1 and MUC5 correlated with mucous differentiation. Both genes were expressed at undetectable or very low levels in undifferentiated cultures, but both mucins became strongly expressed during mucous differentiation. Furthermore, neither mucin gene was expressed in retinoid-deficient cultures that undergo squamous instead of mucous differentiation. These studies demonstrate that expression of MUC1 and MUC5 is coordinately regulated with airway mucous cell differentiation. These cDNAs should provide useful tools to study mucin synthesis during differentiation and disease.

Nuclear accumulation of interferon gamma

Examination of the interferon gamma (IFN-gamma) amino acid sequence revealed two conserved basic amino acid clusters similar to the prototype nuclear localization signal. We followed the fate of cell surface receptor-bound IFN-gamma in murine leukemia L1210 cells. A time- and temperature-dependent accumulation of murine IFN-gamma in the cell nucleus could be demonstrated by autoradiography and indirect immunofluorescence after the rapid isolation of nuclei. Human IFN-gamma was also internalized and translocated to the nucleus of murine L1210 cells transfected with and expressing the human IFN-gamma receptor, but it appeared to be retained by the nucleus only transiently. IFN-gamma molecules chemically crosslinked to their cell surface receptor remain capable of being translocated to the nucleus even as part of a receptor-ligand complex. Thus, the bipartite nuclear localization signal sequence appears to be functional and suggests that nuclear targeting could participate in IFN-gamma signal transduction.

Poor perinatal outcome associated with retained cerclage in patients with premature rupture of membranes

OBJECTIVE

To evaluate the role of immediate cerclage removal versus retention in patients experiencing premature rupture of the membranes remote from term (PROM).

METHODS

Thirty patients with prophylactic cerclage experiencing PROM at 24-32 weeks were managed expectantly after either immediate removal in 20 (67%) or retention of the cerclage in ten (33%). Thirty-three patients without cerclage and with PROM at the same gestational age were used as controls.

RESULTS

More patients with retained cerclage (nine of ten, 90%) had delivery delayed for at least 48 hours after PROM compared to patients with immediate cerclage removal (ten of 20, 50%) (P < .05). Perinatal mortality was significantly higher for those with retained cerclage (seven of ten, 70%) than with immediate removal (two of 20, 10%) or in the control group (six of 33, 18%) (P < .001). Sepsis was responsible for most of the poor outcomes in the retained-cerclage group (71%).

CONCLUSIONS

Although retaining the cerclage prolonged the latency period between PROM and delivery, that benefit was more than offset by a greatly increased perinatal mortality rate. Our study supports immediate cerclage removal regardless of gestational age in cases of PROM.

Modulation of murine and human interferon-gamma receptor expression by their ligands or phorbol ester

IFN-gamma receptor expression on murine leukaemic L1210-cells has been studied. With the help of a transfected cell-line expressing the heterologous human receptor it was possible to discern receptor-specific properties like internalization from those regulating their expression on the surface. Recombinant IFN-gamma binds specifically to its homologous receptor at 4 degrees C and is rapidly internalized at physiologic temperatures. For this effect to occur, ligand binding to its receptor at 37 degrees C is necessary and sufficient. This notion is confirmed since a reduction in the number of heterologous human IFN-gamma receptors on the murine cell surface occurred exclusively after treatment with human IFN-gamma. Even weak doses of ligand, insufficient to occupy all receptors, led to a pronounced disappearance of binding sites. However, both receptors are simultaneously up-regulated in the presence of TPA, indicating a separate pathway which is not species-specific. Our findings imply that similar elements of the intracellular signal transduction machinery are involved in the control of MuIFN-gamma and HuIFN-gamma receptor expression. The results indicate also that factors involved in binding, internalization, and regulation of receptor gene expression are not species-specific.

Antiviral activity of the prostanoid clavulone II against vesicular stomatitis virus

Prostaglandins of the A series exhibit the most pronounced antiviral activity in cells infected with RNA or DNA viruses as compared to other prostaglandins. Clavulone is a prostaglandin A analog found in the soft coral Clavularia viridis. Using vesicular stomatitis virus in mouse L929 fibroblasts as a model system, 50% inhibition of viral yield was seen at a concentration of 1-1.5 microM, whereas 50% cytotoxicity required 50-70 times higher inhibitor concentrations. For a further elucidation of the antiviral mechanism a temperature-sensitive mutant, tsG 41, was used, which is replication-negative at the restrictive temperature. Results obtained with this mutant suggest that inhibition of VSV replication occurs at the level of transcription.

Inhibition of primary transcription of vesicular stomatitis virus by prostaglandin A1

Prostaglandin A (PGA) exhibits antiviral activity against RNA and DNA viruses. The effect of PGA1 on vesicular stomatitis virus (VSV) was investigated. When VSV-infected L-1210 cells were kept in the presence of PGA1 the amount of all five viral proteins and their respective mRNAs was dose-dependently decreased. To determine whether the effect was on viral transcription or translation, the temperature-sensitive VSV mutant tsG 41 was employed. This is a good model system for the investigation of primary transcription; at the restrictive temperature of 39 degrees C, tsG 41 is unable to replicate but can transcribe viral mRNA. Mutant mRNA synthesis was strongly inhibited by PGA1 at this temperature, indicating that the major effect is on primary transcription. This conclusion is supported by data demonstrating that in vitro transcription of viral genomic RNA was also inhibited by PGA1.