Post-traumatic Radioulnar Synostosis in Distal Forearm Fractures in Children: A Report of 2 Cases

CASES

Two pediatric cases of post-traumatic distal radioulnar synostosis are reported, accompanied by a literature review summarizing evidence on the management of these conditions. Radioulnar synostosis is a rare complication of distal forearm fractures, which impairs upper-extremity function. The numerous surgical procedures that have been described to treat this condition in adults typically involve synostosis resection and an interposition graft to reduce recurrence. The optimal treatment in children has not been established.

CONCLUSIONS

Post-traumatic radioulnar synostoses are rare conditions in pediatric patients who can be successfully treated with surgical excision of the synostoses and without the use of interposition grafting.

Is anterior subcapital shortening osteotomy a reliable and reproducible technique in the treatment of severe slipped capital femoral epiphysis?

INTRODUCTION

Proximal femoral shortening osteotomies are becoming the treatment of choice for severe slipped capital femoral epiphysis (SCFE) to reduce the risk of femoroacetabular impingement. The reported rates of complication seem reasonable, but these are single-operator series with surgeons highly experienced in this technique. The purpose of this study was to assess how surgeon experience impacted the outcomes of anterior subcapital shortening osteotomy (ASSO) in severe SCFE.

HYPOTHESIS

The hypothesis was that ASSO is a reproducible technique that is accessible to junior surgeons.

MATERIALS AND METHODS

All ASSOs performed for severe SCFE (slipangle > 40°) between 2015 and 2019 were retrospectively reviewed. All osteotomies were performed by surgeons with less than 4 years' experience (senior residents), who were trained by a senior surgeon experienced in this technique (Group 1). The incidence of femoral head avascular necrosis (AVN) and complications were analyzed and compared to a historical control cohort (Group 2).

RESULTS

A total of 62 SCFEs (37 unstable and 25 stable) were analyzed. Both groups had similar demographic data and SCFE characteristics. The mean operative times were statistically comparable in both groups. The rates of AVN in unstable SCFEs and in the overall series were comparable in both groups (18.9% vs. 13.3%, p=.55 and 12.9% vs. 9.7%, p=.6). These rates were comparable in the stable forms (4.0% vs. 5.4%; p=1). However, the preoperative MRI in Group 1 showed that 42.8% of unstable hips that developed AVN were already hypoperfused before surgery. The overall rate of complication showed no significant difference between the 2 groups (26% vs. 17%, p=.16).

DISCUSSION

Although ASSO is a technically demanding procedure, it is reliable and reproducible. The main risk factor for developing AVN remains the unstable nature of SCFE and not the surgeon's experience. It can be performed by trained junior surgeons, but not in an emergency setting, with the possibility of assistance from a more experienced surgeon.

LEVEL OF EVIDENCE

IV; retrospective case study.

Upper limb extravasation of cytotoxic drugs: results of the saline washout technique in children

PURPOSE

Extravasation of cytotoxic vesicant drugs is a surgical emergency (within six hours) since this incident can lead to severe skin and soft-tissue damage. Outcomes after the saline washout procedure have been extensively described in adults, but rarely in children. The aim of this study was to evaluate the outcome of early saline washout procedure for upper limb cytotoxic drug extravasation in children.

METHODS

All consecutive children with vesicant drug extravasation were retrospectively reviewed. The saline washout procedure was performed. Cosmetic aspect, residual pain and range of movement were analyzed as well as time to surgery and chemotherapy resumption at last follow-up.

RESULTS

Between 2014 and 2018, 13 cytotoxic vesicant drug extravasations occurred (mean age 8 years (sem 5)), including 11 treated by the saline washout procedure. At mean follow-up of 11 months (sem 7), the patients had no or low pain and ranges of movement were fully conserved. Two patients (one within the six hours' delay) had soft-tissue necrosis leading to extensive reconstructive surgery.

CONCLUSION

The saline washout procedure is safe and easy and significantly reduces the incidence of extensive skin damage. Early referral to a specialized department is essential. However, the key parameter remains prevention by educating medical staff and nurses about these injuries and by training them for early and urgent management.

LEVEL OF EVIDENCE

IV.

External fixation: Role in decreasing postoperative complications of complex syndactyly release - A review of 18 patients

BACKGROUND

Primary and revision surgery for complete complex congenital syndactyly (CCCS) of the hand carries a risk of complications such as web maceration, which can result in flap or graft loss and alter the final appearance. No consensus emerges from the scant published data on postoperative care after CCCS surgery. The objective of this study was to assess the role for temporary external fixation in stabilising the commissure and facilitating surgical wound care.

HYPOTHESIS

Using external fixation after CCCS release facilitates postoperative wound care and decreases the complication rate.

MATERIAL AND METHODS

Eighteen patients requiring primary CCCS surgery or revision CCCS surgery due to adhesions or web creep were included in a single-centre retrospective study. After release, an external fixator made of Kirschner pins was installed to temporarily immobilise the inter-phalangeal joints. The dressing was changed every 3 days for 3 weeks, and the external fixator was then removed. The parents and nurses completed questionnaires that used 0-10 point scales to assess ease and duration of dressing changes and perceptions and apprehensions experienced by parents and nurses, as well as pain by patients, during dressing changes.

RESULTS

No patient experienced maceration or failure of a graft or flap. Pin site discharge was noted in 1 patient and resolved fully after pin removal. Pain intensity was estimated at 4.2/10 during the first dressing change and 1.3/10 during the last dressing change. In the parents, apprehension was 9.6/10 and 5.1/10 during the first and last dressing changes, and stress was 8.1/10 and 4.1/10, respectively. Dressing change difficulty was rated 1.1/10 at the first and 0.9/10 at the last dressing change. Dressing change duration decreased from 13 to 10minutes.

CONCLUSION

These encouraging results support temporary commissure stabilisation by an external fixator to decrease postoperative complication rates and facilitate dressing changes after CCCS release.

LEVEL OF EVIDENCE

IV, retrospective observational study.

Infectious flexor hand tenosynovitis: State of knowledge. A study of 120 cases

INTRODUCTION

Since Kanavel in 1905, knowledge of phlegmon of flexor tendon sheaths of the fingers have evolved over the twentieth century. This serious infection is 20% of infections of the hand and may have adverse consequences for the function of the finger and even beyond, of the hand. Amputation is always a risk. Frequently face this type of infection, we conducted a retrospective study and made an inventory of knowledge in order to consolidate and improve the overall care.

MATERIALS & METHODS

The study was retrospective and cross, focused on 120 patients operated on at Hand Surgery Unit, during 4 years. Inclusion criteria were primary or secondary infection of the sheath of the flexor tendons of the fingers.The evaluation focused on clinical and paraclinical perioperative parameters. At last follow, digital mobility (Total Active Motion), the functional score of QuickDASH and the socio-professional consequences were evaluated.

RESULTS

The mean age was 40 years, with a male predominance. The hospital stay was 17 days on average (3 days to 80 days). From the classification of Michon, as amended by Sokolow, we found 60 Stage I, 48 stage II, 12 stage III. The Total Active Motion was respectively 240 °, 140 °, 40 °. QuickDASH scores were respectively 20, 56 and 90 out of 100. The time for return to work was 1 month for stage I, 4 months for stage II and 12 months for stage III.

DISCUSSION

The long-term functional outcome was generally poor, with stiffness or digital amputation. The poor prognostic factors were: the initial advanced stage of infection, infection beta-haemolytic Streptococcus group A, and delayed surgical management. Smoking was identified as a new risk factor in this disease, as well as diabetes or immunodeficiency. This study confirmed the predominance of Staphylococcus, and scalability of the infection depending on the mode of contamination, and / or type of germ that is to say, scalability schedule for β-hemolytic streptococci group A chronic and scalability for intracellular bacteria (mycobacteria).

CONCLUSION

Any suspicion of flexor hand tenosynovitis should lead to an emergency surgical exploration, not primary antibiotics prescription!

Radiological and functional outcomes of high-grade spondylolisthesis treated by intrasacral fixation, dome resection and circumferential fusion: a retrospective series of 20 consecutive cases with a minimum of 2 years follow-up

PURPOSE

Major concern during surgery for high-grade spondylolisthesis (HGS) is to reduce lumbosacral kyphosis and restore sagittal alignment. Despite the numerous methods described, lumbosacral fixation in HGS is a challenging technique associated with high complication rate. Few series have described outcomes and most of the results are limited to lumbosacral correction without global sagittal alignment analysis. This study aims at analyzing clinical and radiological outcomes of HGS patients treated with intrasacral rods on full spine radiographs.

METHODS

HGS patients (Meyerding III or higher) operated between 2004 and 2014 were reviewed. All patients underwent full spine stereoradiographic images. After L5 and S1 decompression, reduction and circumferential fusion with intrasacral rod fixation and fusion up to L4 were performed under fluoroscopy. The entry points for S1 screws were located 3-5 mm above and 5 mm lateral to the first sacral hole, toward the promontory. The two short distal fusion rods were then positioned into the sacrum guided by anteroposterior fluoroscopy using Jackson's technique. Then, sacral dome resection was performed and a PEEK cage was impacted in L5S1 after reduction. Postoperatively, the hip and knee were kept flexed at 45° for 1 week and extended progressively. Preoperative, 3 months postoperative and last follow-up (> 2 years minimum) clinical and radiographic data were collected. Sagittal parameters included lumbosacral angle (LSA), olisthesis, T1 spinopelvic inclination (T1SPi) and spinopelvic parameters.

RESULTS

20 HGS patients were included (8 ptosis, 5 Meyerding IV). The mean age was 14 years. At final FU (7.2 years ± 3), LSA kyphosis and olisthesis were reduced (65° ± 14 vs 99° ± 11, p < 0.001 and 81% ± 19 vs 45% ± 18, p < 0.001, respectively). While L1L5 lordosis decreased, T1T12 kyphosis increased. At FU, global alignment with T1SPi was - 6° ± 3. No significant loss of correction was observed. Regarding complications, ten patients presented transient L5 motor deficit that occurred when patients were put in standing position. However, all recovered before 3 months postoperatively.

CONCLUSION

Intrasacral rod fixation appears to be an effective technique to correct LSA kyphosis, compensatory hyperlordosis and restore global sagittal alignment with a postoperative T1SPi corresponding to the value of the asymptomatic subject and achieve fusion. However, it remains a demanding technique with high risk of transient neurologic complications.

Video-assisted functional assessment of index pollicisation in congenital anomalies

PURPOSE

Functional results of index pollicisation are usually assessed by the clinical score of Percival. This score is based on elementary hand movements and does not reflect the function of the neo thumb in daily life activities. The aim of this study was to develop a new video-assisted scoring system based on daily life activities to assess index pollicisation functional outcomes.

METHODS

Twenty-two consecutive children, operated between 1998 and 2012, were examined with a mean of 77 months after surgery. The mean age at surgery was 34 months. Post-operative results were evaluated by a new video-assisted 14-point scoring system consisting of seven basic tasks that are frequently used in daily activities. The series of tasks was performed both on the request of the examiner and in real-life conditions with the use of a hidden camera. Each video recording was examined by three different examiners. Each examiner rated the video recordings three times, with an interval of one week between examinations. Inter- and intra-observer agreements were calculated.

RESULTS

Inter- and intra-observer agreements were excellent both on request (κ = 0.87 [0.84-0.97] for inter-observer agreement and 0.92 [0.82-0.98] for intra-observer agreement) and on hidden camera (κ = 0.83 [0.78-0.91] for inter-observer agreement and 0.89 [0.83-0.96] for intra-observer agreement). The results were significantly better on request than on hidden camera (p = 0.045). The correlation between the video-assisted scoring system and the Percival score was poor.

CONCLUSION

The video-assisted scoring system is a reliable tool to assess index pollicisation functional outcomes. The scoring system on hidden camera is more representative of the neo thumb use in daily life complex movements.

LEVEL OF EVIDENCE

Level IV.

Impact of calcineurin-inhibitor conversion to mTOR inhibitor on renal allograft function in a prednisone-free regimen

Traditionally, chronic calcineurin inhibitor (CNI) nephrotoxicity has been considered to be one of the main nonimmune mechanisms causing chronic renal allograft dysfunction. CNI minimization and withdrawal strategies have yielded inconsistent results. Few studies address the feasibility of CNI elimination in a prednisone-free regimen. We report a prospective, randomized trial in 200 patients evaluating the impact on renal function and incidence of acute rejection after conversion from tacrolimus (Tac) to sirolimus (SRL). Patients with recent (<3 months) acute rejection episodes or with >0.5 g/day of proteinuria were excluded. All were induced with alemtuzumab, underwent rapid steroid elimination and were maintained on mycophenolate mofetil and Tac. At 12 months posttransplant, patients were randomized 2:1 to SRL (n = 123) or maintained on Tac (n = 64). Mean follow-up was 41.1 ± 15.8 months in the SRL group and 40.7 ± 14.4 months in the Tac group. Biopsy-proven acute rejection at 24 months postrandomization was similar between the groups. Patient survival, graft survival and estimated GFR were also not statistically different. Our study demonstrates that in a prednisone-free immunosuppressive regimen, conversion from Tac to SRL at 12 months posttransplantation is not associated with increased rates of acute rejection and graft loss. However, despite CNI elimination, renal allograft function is equally maintained in both groups.

[Metacarpal osteoarticular injuries in children]

Metacarpal fractures and dislocations in the fingers are common injuries in children's hands. Most of these can be treated successfully non-operatively, although a subset requires more aggressive treatment. Results following appropriate care in children are generally good. Twenty percent of them need a reduction, need for surgical stabilization is rare. Each injury is presented, including diagnostic, therapeutic principles, pitfalls to prevent and potential complications.

MicroRNA profiles in allograft tissues and paired urines associate with chronic allograft dysfunction with IF/TA

Despite the advances in immunosuppression, renal allograft attrition over time remains unabated due to chronic allograft dysfunction (CAD) with interstitial fibrosis (IF) and tubular atrophy (TA). We aimed to evaluate microRNA (miRNA) signatures in CAD with IF/TA and appraise correlation with paired urine samples and potential utility in prospective evaluation of graft function. MiRNA signatures were established between CAD with IF/TA versus normal allografts by microarray. Validation of the microarray results and prospective evaluation of urine samples was performed using real-time quantitative-PCR (RT-qPCR). Fifty-six miRNAs were identified in samples with CAD-IF/TA. Five miRNAs were selected for further validation based on array fold change, p-value and in silico predicted mRNA targets. We confirmed the differential expression of these five miRNAs by RT-qPCR using an independent set of samples. Differential expression was detected for miR-142-3p, miR-204, miR-107 and miR-211 (p < 0.001) and miR-32 (p < 0.05). Furthermore, differential expression of miR-142-3p (p < 0.01), miR-204 (p < 0.01) and miR-211 (p < 0.05) was also observed between patient groups in urine samples. A characteristic miRNA signature for IF/TA that correlates with paired urine samples was identified. These results support the potential use of miRNAs as noninvasive markers of IF/TA and for monitoring graft function.

Dual antiviral activity of human alpha-defensin-1 against viral haemorrhagic septicaemia rhabdovirus (VHSV): inactivation of virus particles and induction of a type I interferon-related response

It is well known that human alpha-defensin-1, also designated as human neutrophil peptide 1 (HNP1), is a potent inhibitor towards several enveloped virus infecting mammals. In this report, we analyzed the mechanism of the antiviral action of this antimicrobial peptide (AMP) on viral haemorrhagic septicaemia virus (VHSV), a salmonid rhabdovirus. Against VHSV, synthetic HNP1 possesses two antiviral activities. The inactivation of VHSV particles probably through interfering with VHSV-G protein-dependent fusion and the inhibition of VHSV replication in target cells by up-regulating genes related to the type I interferon (IFN) response, such as Mx. Neither induction of IFN-stimulated genes (ISGs) by HNP1 nor their antiviral activity against fish rhabovirus has been previously reported. Therefore, we can conclude that besides to acting as direct effector, HNP1 acts across species and can elicit one of the strongest antiviral responses mediated by innate immune system. Since the application of vaccine-based immunization strategies is very limited, the used of chemicals is restricted because of their potential harmful impact on the environment and no antimicrobial peptides from fish that exhibit both antiviral and immunoenhancing capabilities have been described so far, HNP1 could be a model molecule for the development of antiviral agents for fish. In addition, these results further confirm that molecules that mediate the innate resistance of animals to virus may prove useful as templates for new antivirals in both human and animal health.

Identification of selective inhibitors of VHSV from biased combinatorial libraries of N,N′-disubstituted 2,5-piperazinediones

A combinatorial strategy has been used to design and identify inhibitors of viral haemorrhagic septicemia virus (VHSV), a salmonid rhabdovirus of economic importance. Two libraries of N,N'-disubstituted 2,5-piperazinediones (DKP), DKP-I and DKP-II were screened for inhibition of VHSV infectivity. Among the 98 DKP-derivatives (R1-DKP-R2) screened, a novel class of VHSV in vitro inhibitors was identified. Evidences are presented showing that the selected DKP-derivatives cause dose-dependent inhibition of VHSV infectivity in the absence of cellular toxicity. Preliminary characterization of its inhibition mechanism ruled out direct inactivation of the virus (virucidal effect) or interference with early viral replication steps. Furthermore, analysis of infection foci sizes, virus titers, viral protein accumulation and presence of cell free virus derived from VHSV-infected cell cultures in the presence of DKP-derivates suggested that virus assembly/release was impaired leading to a reduced virus spread in cell culture. New DKP-derivatives with a significant higher specific activity need to be developed to start testing its possible practical use but the selected DKP-derivatives described here may contribute to their further development as well as being tools to improve our knowledge on the fish rhabdovirus infection cycle.

Stable expression of bioactive recombinant pleurocidin in a fish cell line

Pleurocidin (Ple), a linear cationic peptide of 25 amino acids, is a member of a larger family of antimicrobial peptides present in flatfish. Previous studies have shown that Ple displays a strong antimicrobial activity against a broad spectrum of bacteria and appears to play a role in innate host defence. In this work, the genomic sequence encoding the Ple prepropeptide has been isolated from Limanda limanda and cloned in a vector under the control of a non-viral promoter (the carp beta-actin promoter). By using this construction, expression of bioactive Ple was demonstrated in transformed fish cell lines continuously growing for more than 2 years. Furthermore, the study of Ple processing, maturation and secretion (by using fusion with green fluorescence protein) and the high bactericidal activity of the secreted recombinant Ple (detectable in cell supernatants without any concentration) are all reported here, as no other recombinant Ple or fish antimicrobial peptide have been expressed before to that extent. Such an overexpression of recombinant Ple or any other related antimicrobial peptide might improve the chances to develop new antibiotic agents, as well as to provide essential information about the mechanism of action, range of activity and the role in the innate immune response of antibiotic peptides.

Description of a novel HLA-DRB1 allele found in a candidate for bone marrow transplantation*

We report the identification of a new DRB1* allele in a Spanish Caucasoid family during a search for a histocompatible bone marrow donor. This novel allele, designated as DRB1*1145, differs from DRB1*1123 in one nucleotide at position 199 in exon 2 (A replacing T), leading to one amino acid change from phenylalanine (Phe) to isoleucine (Ile) at codon 67. The propositus's father had identical class II alleles but showed a minor mismatch at locus B (B*4403 by B*4402) and a C-locus mismatch (Cw*1502 by Cw*0501). We discuss the criteria of selecting a non-related bone marrow donor with a minor mismatch on the DRB1* allele or the related father having a minor mismatch at B locus and a C-locus mismatch.

Reversible inhibition of spreading of in vitro infection and imbalance of viral protein accumulation at low pH in viral hemorrhagic septicemia rhabdovirus, a salmonid rhabdovirus

The inhibition of viral hemorrhagic septicemia rhabdovirus (VHSV) in vitro infection by pHs of <7 (low pH) has been previously reported. Nevertheless, the details of the mechanism underlying this effect remain obscure. We present evidence showing that low-pH inhibition occurs during a viral postadsorption step. Thus, while VHSV bound, replicated within single cells, and presented its G protein on the membranes of infected cells at both low and physiological pHs, both cell-to-cell spreading of infection (as estimated by the appearance of foci of infected cells) and fusion (as estimated by a syncytium assay) were inhibited by this low pH. The decreased VHSV titers and the inhibition of both cell-to-cell spreading of infection and fusion could be reversed by adjusting the pH to 7.5 at any time during infection. This effect should be taken into account to avoid false negatives in the diagnosis of VHSV by cell culture. On the other hand, the cell-to-cell spreading of infection at pH 7.5 could be stopped at any time by reducing the pH to 6.5. Since at low pH there were changes in the protein G conformation and smaller and imbalanced amounts of N with respect to M1, M2, and G viral proteins, alterations of the assembly and/or budding of VHSV are most probably involved in the absence of newly released infective virions.

Characterization of a new HLA-C allele: Cw*1606

HLA-Cw*16 is a relatively common HLA-C specificity among Caucasoids, with Cw*1601 being the most frequent allele. We report herein the identification by sequence-based typing of a new HLA-Cw*16 allele in a Spanish Caucasoid blood donor. The novel allele, designated Cw*1606, differs from Cw*1601 by two nucleotide changes at positions 361 (T to A) and 368 (A to C) in exon 3, which leads to two amino acid changes from Trp (TGG) to Arg (AGG) and from Tyr (TAT) to Ser (TCT) at codons 97 and 99 in the alpha2 domain, respectively. Sequence comparisons suggest that the new HLA-Cw*1606 variant could have arisen from an intralocus gene conversion event.

Salmonid viral haemorrhagic septicaemia virus: fusion-related enhancement of virus infectivity by peptides derived from viral glycoprotein G or a combinatorial library

To search for enhancers and/or inhibitors of viral haemorrhagic septicaemia virus (VHSV, a salmonid rhabdovirus) infectivity, a total of 51 peptides from a pepscan of viral envelope protein G, a recombinant peptide from protein G (frg11) and 80 peptide mixtures from an alpha-helix-favoured combinatorial library were screened. However, contrary to what occurs in many other enveloped viruses, only peptides enhancing rather than inhibiting VHSV infectivity were found. Because some of the enhancer pepscan G peptides and frg11 were derived from phospholipid-binding or fusion-related regions identified previously, it was suggested that enhancement of virus infectivity might be related to virus-cell fusion. Furthermore, enhancement was significant only when the viral peptides were pre-incubated with VHSV at the optimal low pH of fusion, before being adjusted to physiological pH and assayed for infectivity. Enhancement of VHSV infectivity caused by the pre-incubation of VHSV with peptide p5 (SAAEASAKATAEATAKG), one of the individual enhancer peptides defined from the screening of the combinatorial library, was independent of the pre-incubation pH. However, it was also related to fusion because the binding of p5 to protein G induced VHSV to bypass the endosome pathway of infection and reduced the low-pH threshold of fusion, thus suggesting an alternative virus entry pathway for p5-VHSV complexes. Further investigations into VHSV enhancer peptides might shed some light on the mechanisms of VHSV fusion.

Enhanced detection of viral hemorrhagic septicemia virus (a salmonid rhabdovirus) by pretreatment of the virus with a combinatorial library-selected peptide

A 17-mer peptide (SAAEASAKATAEATAKG, p5) was selected by screening a combinatorial library for its ability to enhance in vitro the infectivity of viral hemorrhagic septicemia virus (VHSV), a salmonid rhabdovirus. Preincubation of VHSV samples with p5 at micromolar concentrations led to up to 5-fold increase of viral titers compared to untreated samples, as measured by a 1-day post-infection immunochemical focus assay. Treatment with p5 also increased VHSV titers when using the more traditional plaque and end-point dilution assays. Preincubation of p5 with infectious hematopoietic necrosis virus (another rhabdovirus of salmonids), but not with infectious pancreatic necrosis virus (birnavirus) also led to a similar increase in sensitivity. These results indicate that the addition of p5 may be used to improve the sensitivity of diagnostic tests for salmonid rhabdoviruses.

Intragraft messenger RNA expression of angiotensinogen: relationship with transforming growth factor beta-1 and chronic allograft nephropathy in kidney transplant patients

Transforming growth factor (TGF)-beta1 is important in fibrogenesis and has been involved in the pathogenesis of chronic allograft nephropathy (CAN). The angiotensinogen (AGT) gene encodes the only glycoprotein known to be a precursor of the vasopressor angiotensin II. Angiotensin II is also a growth factor and a profibrogenic cytokine. It mediates the induction of TGF-beta1. We studied the relationship among the intragraft expression of AGT, TGF-beta1, and CAN in stable renal transplant patients (RTP). We used a competitive quantitative reverse transcriptase-polymerase chain reaction (RT-PCR)-ELISA assay to identify intragraft amounts of AGT expression in RTP and correlated it with TGF-beta1 mRNA expression. We studied and performed kidney biopsies on 12 RTP with long-functioning grafts and 6 RTP in the immediate posttransplantation period (7 days) who had acute tubular necrosis as control. Histology was based on Banff working classification criteria. Total RNA was isolated from biopsy specimens. For RT-PCR-ELISA, we created heterologous RNA competitors that coamplified with the same primers as AGT and TGF-beta1. Six of 12 long RTP had proteinuria >1000 mg/24 hr and 6 had proteinuria <1000 mg/24 hr. The differences between Banff grades (P =0.03), AGT, and TGF-beta1 levels by RT-PCR-ELISA were statistically significant between both groups (106.2+/-60.7 vs. 34.1+/-11.9 pg/microg total RNA [P =0.01] and 5954+/-5612 vs. 436+/-517 transcripts/microg total RNA [P =0.01], respectively). The control group showed AGT levels of 25+/-12.2 pg/microg total RNA and TGF-beta1 levels of 228+/-111 transcripts/microg total RNA, significant only for the higher proteinuria group (P=0.01 and P=0.04, respectively). There was a correlation between AGT and TGF-beta1 in both groups (r=0.96, P=0.001). We showed a relationship between mRNA expression of AGT and TGF-beta1 in kidney transplant patients with different grades of CAN and proteinuria.

Antibody response to a fragment of the protein G of VHS rhabdovirus in immunised trout

A fragment (called frg#11, amino acids, aa 56-110) of the protein G (pG) of viral haemorrhagic septicaemia virus (VHSV) was designed after previous results showed it to be recognised by approximately 40% of the trout immunised to VHSV [Dis. Aquat. Organ. 34 (1999) 167]. frg#11 was then cloned, expressed, purified and used to study the production of antibodies to its epitopes in trout immunised to VHSV. Anti-frg#11 trout antibodies could be detected in serum from individual trout surviving VHSV exposure, immunised by injection with purified VHSV or DNA-immunised with its pG gene whereas it was not detected in non-infected and non-immunised trout. The trout serum antibodies which reacted more strongly by ELISA using solid-phase frg#11 (continuous or linear epitopes on the sequence of the pG) had the lowest VHSV-neutralising activity (epitopes which are pG conformation-dependent). Because antibodies recognising continuous as well as conformation-dependent epitopes of the pG seem to be involved in protective trout immunological responses to VHSV, the estimation of anti-frg#11 antibodies could help to the dissection of the complex trout antibody response to VHSV infections. In addition, these preliminary results suggest that the determination of anti-frg#11 antibodies might also be used to complement in vitro viral neutralising assays which seem to be restricted to pG conformation-dependent epitopes.

A protein G fragment from the salmonid viral hemorrhagic septicemia rhabdovirus induces cell-to-cell fusion and membrane phosphatidylserine translocation at low pH

The fusion-related properties of segments p9, p3, p4, and p9 + p2 surrounding the p2 phospholipid-binding domain of the protein G (pG) of the salmonid rhabdovirus of viral hemorrhagic septicemia (VHS) (Nuñez, E., Fernandez, A. M., Estepa, A., Gonzalez-Ros, J. M., Gavilanes, F., and Coll, J. M. (1998) Virology 243, 322-330; Estepa, A., and Coll, J. M. (1996) Virology 216, 60-70), have been studied at neutral and fusion (low) pH values by using its derived peptides. Cell-to-cell fusion, translocation of phosphatidylserine, and inhibition of fusion of pG-transfected cells defined the p9 + p2 (fragment 11, sequence 56-110) as a fragment with higher specific activity for anionic phospholipid aggregation than the previously reported p2. While fragment 11, p2, and p3 showed interactions with anionic phospholipids, p9 and p4 showed no interactions with any phospholipids. When added to a cell monolayer model at low pH, fragment 11 induced pH-dependent cell-to-cell fusion and translocated phosphatidylserine from the inner to the outer leaflet of the membrane. At low pH and in the presence of anionic phospholipids, fragment 11 showed more than 80% beta-sheet conformation (IR and CD spectroscopies). Finally, anti-fragment 11 antibodies inhibited low pH-dependent pG-transfected cell-to-cell fusion. All of the data support the conclusion that fragment 11 is a primary determinant of some of the viral cell fusion events in VHSV.

Intragraft expression of transforming growth factor-beta 1 by a novel quantitative reverse transcription polymerase chain reaction ELISA in long lasting kidney recipients

BACKGROUND

Chronic allograft nephropathy (CAN) remains a major problem in clinical transplantation. It has been associated with increased transforming growth factor (TGF-beta1). Our goal was to correlate CAN and levels of TGF-beta1 by using a novel competitive quantitative for reverse transcription-polymerase chain reaction-ELISA (RT-PCR-ELISA) assay.

METHODS

We studied 12 transplantation patients (posttransplant time: 36.5+/-11.2 months, range (r): 13-52) with stable creatinine and blood pressure and varied proteinuria. A Kidney biopsy was performed in all patients. Six patients with acute tubular necrosis (ATN) immediately after transplantation were used as controls. Histopathological evaluation was based on Banff working classification criteria. We designed an heterologous RNA competitor (IC) for RT-PCR-ELISA, which co-amplified with the same primer as TGF-beta1. Products were viewed on 96-well plates labeled with probes for IC at the desired sequence.

RESULTS

Results were expressed as the number of TGF-beta1 copies/microg of total RNA. Six patients showed more than 1000 mg/24 hr proteinuria (2446+/-1421 mg/24 hr, r: 1200-5000) higher CAN Banff scores, and the other six presented <1,000 mg/24 hr (348+/-267 mg/24 hr, r: 114-800). This difference was significant (P=0.01). There were not significant differences in posttransplant time, creatinine, or blood pressure between groups. TGF-beta1 levels by RT-PCR-ELISA were statistically significant (6038+/-5317, r: 1239-12100 versus 177+/-119.7, r: 51-400, P=0.04). The control group showed levels of 228+/-111, r. 140-444, P=0.04) with significant difference only for the higher proteinuria group (P=0.03).

CONCLUSIONS

This study showed that those patients with elevated CAN scores and higher proteinuria levels had higher TGF-beta1 intragraft expression.

Utility of cytomegalovirus viral load in renal transplant patients in Argentina

BACKGROUND

Cytomegalovirus (CMV) is the most prevalent viral disease in solid organ transplantation. Detection of CMV DNA in peripheral blood mononuclear cells (PBMC) by polymerase chain reaction (PCR) frequently occurs in renal allograft recipients, yielding false positive results in seropositive patients free of CMV disease. We evaluated the clinical utility of a quantitative PCR-enzyme-linked immunosorbent assay (ELISA) for identifying patients with CMV disease.

METHODS

Three hundred and fifty samples from 65 consecutive renal transplant recipients were studied. DNA was extracted from PBMC weekly up to the day of discharge and after any further admission. Samples were tested by a qualitative PCR method, and all positive samples were further studied by a quantitative PCR-ELISA method. The quantitative PCR-ELISA method used an internal standard (IS) that contained the primer sequences used in the qualitative CMV PCR. Detection and quantification was performed in 96-well plates coated with IS or CMV specific probes.

RESULTS

Forty-one of 65 patients (63.1%) showed positive results by the qualitative PCR, but only 8 of these patients were diagnosed with CMV disease. Positive samples were re-analyzed by the quantitative assay. The 8 patients with CMV disease had a mean CMV viral load of 1,438+/-687 viral copies (VC)/10(6) PBMC, and the 33 without CMV disease had a mean value of 219.6+/-117.2 VC/10(6) PBMC (P<0.01). None of the 33 patients without CMV disease had viral loads higher than 500 VC/10(6) PBMC. Using 500 VC/10(6) PBMC as a cut-off value for CMV disease, the quantitative PCR showed a sensitivity and specificity of 100% compare to clinical diagnosis.

CONCLUSION

CMV viral load may be useful in the diagnosis of CMV disease in renal transplant patients.