What are the short- and long-term abdominal consequences of an omentectomy? A systematic review

This review provides an overview regarding the abdominal effects of an omentectomy, with or without extra-peritoneal reconstructions. In general, reported complication rates were low. Short-term complications involved ileus, bowel stenosis, abdominal abscess and sepsis (range 0.0%-23%). Donor-site hernia was mainly reported as long-term complication (up to 32%) and negligible gastrointestinal complications were observed. However, the level of evidence and methodological quality are quite low with a maximum of 8.5 years follow-up.

Superior Sensibility after Full Breast Reconstruction with Autologous Fat Transfer

BACKGROUND

With developments in screening and treatment, survival rates of breast cancer patients are increasing, and so is the number of women opting for breast reconstruction to improve their quality of life. One factor that could play an important role in improving the quality of life is breast sensibility. Therefore, the aim of this study was to explore breast sensibility in participants of the Breast Reconstruction with External Preexpansion and Autologous Fat Transfer versus Standard Therapy trial: an ongoing randomized controlled trial comparing breast reconstruction with autologous fat transfer (AFT) versus implant-based reconstruction (IBR).

METHODS

This study was conducted on participants of the Breast Reconstruction with External Preexpansion and Autologous Fat Transfer versus Standard Therapy trial who were at least 12 months after final surgery. Semmes-Weinstein monofilaments were used to measure skin sensibility in breast cancer patients who underwent breast reconstruction with either AFT or IBR following their mastectomy.

RESULTS

A total of 46 patients were included in this study, resulting in 62 breast reconstructions (28 AFT breasts and 34 IBR breasts). Significantly higher mean monofilament values were found for skin sensibility after AFT (-0.7; P < 0.001), clinically correlating to "diminished protective function," as opposed to the IBR group, with clinical values indicating "loss of protective function."

CONCLUSIONS

In this study, the authors found that breast cancer patients who underwent a mastectomy had a significantly better sensibility of the breast following AFT for total breast reconstruction as compared with IBR. Larger studies that include null measurements are required to further explore these noteworthy results of AFT.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, II.

Causal inference using observational intensive care unit data: a scoping review and recommendations for future practice

This scoping review focuses on the essential role of models for causal inference in shaping actionable artificial intelligence (AI) designed to aid clinicians in decision-making. The objective was to identify and evaluate the reporting quality of studies introducing models for causal inference in intensive care units (ICUs), and to provide recommendations to improve the future landscape of research practices in this domain. To achieve this, we searched various databases including Embase, MEDLINE ALL, Web of Science Core Collection, Google Scholar, medRxiv, bioRxiv, arXiv, and the ACM Digital Library. Studies involving models for causal inference addressing time-varying treatments in the adult ICU were reviewed. Data extraction encompassed the study settings and methodologies applied. Furthermore, we assessed reporting quality of target trial components (i.e., eligibility criteria, treatment strategies, follow-up period, outcome, and analysis plan) and main causal assumptions (i.e., conditional exchangeability, positivity, and consistency). Among the 2184 titles screened, 79 studies met the inclusion criteria. The methodologies used were G methods (61%) and reinforcement learning methods (39%). Studies considered both static (51%) and dynamic treatment regimes (49%). Only 30 (38%) of the studies reported all five target trial components, and only seven (9%) studies mentioned all three causal assumptions. To achieve actionable AI in the ICU, we advocate careful consideration of the causal question of interest, describing this research question as a target trial emulation, usage of appropriate causal inference methods, and acknowledgement (and examination of potential violations of) the causal assumptions.

Triangular Flap Extension to Create a Meatal Appearance in Phalloplasty Without Urethral Lengthening

OBJECTIVE

To describe an easy-to-perform surgical refinement to create a meatal appearance in phalloplasty without urethral lengthening by using a triangular flap extension.

METHODS

Transgender men undergoing phalloplasty without urethral lengthening are candidate for this flap extension. A triangular flap is drawn at the distal part of the flap. When the flap is raised, this triangle is raised with the flap and subsequently folded in the tip of the neophallus, thus creating a neomeatal appearance.

RESULTS

We present this easy-to-perform technique, our experience and postoperative results. Two pitfalls of this technique are: (1) when it is insufficiently trimmed and thinned, it adds too much bulk to the phallic top and (2) when it is insufficiently vascularized, wound healing problems will occur; especially since the neophallus will swell in the immediate postoperative phase.

CONCLUSION

Using a triangular flap extension is an easy method to create a neomeatal appearance.

Monitoring and Management of Fibrodysplasia Ossificans Progressiva: Current Perspectives

Fibrodysplasia ossificans progressiva (FOP), sometimes known as myositis ossificans progressiva, is an ultra-rare disease in which bone is formed in muscular tissue, tendons and ligaments. This is known as heterotopic ossification (HO). FOP is caused by a heterozygous mutation in the highly conserved ACVR1/ALK2 gene which affects about 1 in 1.5–2 million individuals. At birth, patients with the predominant R206H mutation only exhibit a bilateral hallux valgus. During childhood, heterotopic bone formation develops in a typical pattern, affecting the axial muscles first before appendicular body parts are involved. HO can start spontaneously but is often elicited by soft tissue trauma or medical procedures. After soft tissue injury, an inflammatory process called a flare-up can start, followed by the formation of HO. HO leads to a limited range of motion, culminating in complete ankylosis of nearly all joints. As a result of HO surrounding the thorax, patients often suffer from thoracic insufficiency syndrome (TIS). TIS is the most common cause of a limited life expectancy for FOP patients, with a median life expectancy of 56 years. Management is focused on preventing soft-tissue injury that can provoke flare-ups. This includes prevention of iatrogenic damage by biopsies, intramuscular injections and surgery. Anti-inflammatory medication is often started when a flare-up occurs but has a poor basis of evidence. Several forms of potential treatment for FOP are being researched in clinical trials. Progression of the disease is monitored using CT and 18F-NaF PET/CT combined with functional assessments. Patients are regularly evaluated for frequently occurring complications such as restrictive lung disease. Here, we review the current management, monitoring and treatment of FOP.

The Impact of Incisional Negative Pressure Wound on Scar Quality and Patient Reported Outcomes: a Within-Patient Controlled, Randomized Trial

Literature provides a moderate level of evidence for the beneficial effects of incisional negative pressure wound therapy (iNPWT) on scar quality. The purpose of this study was to establish if iNPWT results in improved scar outcomes in comparison to the standard of care. Therefore, a within‐patient randomised controlled, open‐label trial was conducted in transgender men undergoing gender‐affirming mastectomies. A unilateral side was randomised to receive iNPWT (PICO™, Smith&Nephew) without suction drains and contrastingly the standard dressing (Steri‐Strips™) with suction drain. Scar quality and questionnaires were bilaterally measured by means of objective assessments and patient‐reported outcome measures (PROM) at 1, 3 and 12 months. Objective scar outcomes were scar pliability (Cutometer®), colouration (DSM‐II) and scar width (3‐D imaging). PROM outcomes were related to scars (POSAS and SCAR‐Q) and body satisfaction (BODY‐Q). From 85 included patients, 80 were included for analyses. No significant difference between treatments was seen in the quantitative outcomes of scar pliability, colour, and width. For qualitative scar outcomes, several significant findings for iNPWT were found for several subscales of the POSAS, SCAR‐Q, and BODY‐Q. These effects could not be substantiated with linear mixed‐model regression, signifying no statically more favourable outcome for either treatment option. In conclusion, this study demonstrated that some PROM outcomes were more favourable for the iNPWT compared to standard treatment. In contrast, the quantitative outcomes showed no beneficial effects of iNPWT on scar outcomes. This suggests that iNPWT is of little benefit as a scar‐improving therapy.

Left atrial appendage size is a marker of atrial fibrillation recurrence after radiofrequency catheter ablation in patients with persistent atrial fibrillation

Background

Catheter ablation is an established therapy for rhythm control in patients with drug-refractory atrial fibrillation (AF), however, recurrence is frequent particularly in persistent AF. There are no consistently confirmed predictors of AF recurrence after catheter ablation. The left atrial appendage (LAA) potentially plays an important role in AF recurrence, although the exact mechanism and pathophysiology are still unclear.

Purpose

We aimed to study whether LAA volume (LAAV) and function influence the long-term recurrence of AF after point-by-point radiofrequency catheter ablation, depending on AF type.

Methods

AF patients who underwent point-by-point radiofrequency catheter ablation after preprocedural cardiac computed tomography (CT) and transthoracic and transesophageal echocardiography (TEE) were included in this retrospective analysis. LAAV and LAA orifice area were measured by CT and LAA flow velocity assessed by TEE and was used as a surrogate marker of LAA function. Uni- and multivariable Cox proportional hazard regression models were performed to determine the predictors of AF recurrence.

Results

In total, 561 AF patients (61.9±10.2 years, 34.9% females) were included in the study. Recurrence of AF was detected in 40.8% of the cases (34.6% in patients with paroxysmal and 53.5% in those with persistent AF) with a median recurrence-free time of 22.7 [9.3–43.1] months. Patients with AF recurrence had significantly higher body surface area-indexed left atrial volume (iLAV), LAAV and LAA orifice area, as compared to those without recurrence. Moreover, patients with persistent AF had significantly higher iLAV, LAAV, LAA orifice area and lower LAA flow velocity, than those with paroxysmal AF. After adjustment for the main cardiovascular risk factors and comorbidities left ventricular ejection fraction (LVEF) &lt;50% (HR=2.17; 95% CI=1.38–3.43; p&lt;0.001) and LAAV (HR=1.06; 95% CI=1.01–1.12; p=0.029) were independently associated with AF recurrence in persistent AF, while no independent predictors could be identified in paroxysmal AF.

Conclusions

The current study demonstrates that beyond left ventricular systolic dysfunction, LAA enlargement is associated with higher rate of AF recurrence after catheter ablation in persistent AF, but not in patients with paroxysmal AF. Our results suggest that preprocedural assessment of LVEF and LAAV might contribute to optimal patient selection and aid to improve long-term results of ablation procedures in patients with persistent AF.

Funding Acknowledgement

Type of funding sources: None.

BREAST trial study protocol: evaluation of a non-invasive technique for breast reconstruction in a multicentre, randomised controlled trial

INTRODUCTION

Pioneers have shown that it is possible to reconstruct a full breast using just autologous fat harvested by liposuction or autologous fat transfer (AFT). This study describes the first multicentre randomised study protocol to thoroughly investigate the effectiveness of AFT to reconstruct full breasts following mastectomy procedures (primarily and delayed).

METHODS AND ANALYSIS

This study is designed as a multicentre, randomised controlled clinical superiority trial with a 1:1 allocation ratio. A total of 196 patients (98 patients per treatment arm) are aimed to be included. Patients who wish to undergo breast reconstruction with either one of the two techniques are randomly allocated into the AFT group (intervention) or the tissue-expander/prosthesis group (control). The primary outcome measure for the quality of life is measured by the validated BREAST-Q questionnaire.

ETHICS AND DISSEMINATION

Approval for this study was obtained from the medical ethics committee of Maastricht University Medical Centre/Maastricht University; the trial has been registered at ClinicalTrials.gov. The results of this randomised controlled trial will be presented at scientific meetings as abstracts for poster or oral presentations and published in peer-reviewed journals.

TRIAL STATUS

Enrolment into the trial has started in October 2015. Data collection and data analysis are expected to be completed in December 2021.

TRIAL REGISTRATION NUMBER

NCT02339779.

Within-patient randomized clinical trial comparing incisional negative-pressure wound therapy with suction drains in gender-affirming mastectomies

BACKGROUND

Incisional negative-pressure wound therapy (iNPWT) is widely adopted by different disciplines for multiple indications. Questions about the most appropriate uses and value of iNPWT have been raised.

METHODS

An open-label within-patient RCT was conducted in transgender men undergoing gender-affirming mastectomies. The objective was to determine the effect of iNPWT as a substitute for standard dressing and suction drains on wound healing complications. One chest side was randomized to receive the iNPWT intervention, and the other to standard dressing with suction drain. The primary endpoints were wound healing complications (haematoma, seroma, infection, and dehiscence) after three months. Additional outcomes were pain according to a numerical rating scale and patient satisfaction one week after surgery.

RESULTS

Eighty-five patients were included, of whom 81 received both the iNPWT and standard treatment. Drain removal criteria were met within 24 h in 95 per cent of the patients. No significant decrease in wound healing complications was registered on the iNPWT side, but the seroma rate was significantly increased. In contrast, patients experienced both significantly less pain and increased comfort on the iNPWT side. No medical device-related adverse events were registered.

CONCLUSION

Substituting short-term suction drains with iNPWT in gender-affirming mastectomies increased the seroma rates and did not decrease the amount of wound healing complications. Registration number: NTR7412 (Netherlands Trial Register).

Sustained Breast Development and Breast Anthropometric Changes in 3 Years of Gender-Affirming Hormone Treatment

CONTEXT

Breast development is important for most trans women. An important limitation of current breast development measurement methods is that these do not allow for 3D volume analyses.

OBJECTIVES

To examine breast development and change in anthropometry during the first 3 years of gender-affirming hormone treatment using 3D imaging. Associations with clinical or laboratory parameters and satisfaction with the gained breast development were also studied.

DESIGN

Prospective cohort study.

SETTING

Specialized tertiary gender identity clinic in Amsterdam, the Netherlands.

PARTICIPANTS

Participants were 69 adult trans women with a median age of 26 years (interquartile range, 21-38).

INTERVENTIONS

Gender-affirming hormone treatment.

MAIN OUTCOME MEASURES

Volumetric and anthropometric breast development and satisfaction.

RESULTS

Breast volume increased by 72 cc (95% confidence interval [CI], 48-97) to 100 cc (standard deviation 48). This resulted in a cup-size <A-cup in 71% of the participants. Although the change in breast-chest difference plateaued after approximately 9 months, sustained increase in breast volume was observed during the 3-year observation period. Sternal notch to nipple distance increased by 1.3 cm (95% CI, 0.9-1.7) and internipple distance increased by 1.0 cm (95% CI, 0.4-1.5). At least 58% of trans women were satisfied with the gained breast size.

CONCLUSIONS

Sustained breast growth and development during hormone treatment was observed during the full 3-year observation period. The breasts of trans women are positioned more laterally and caudally on the chest compared with cis women. Although modest breast volumes were observed, breast development was satisfactory to most trans women.

When Limb Surgery Has Become the Only Life-Saving Therapy in FOP: A Case Report and Systematic Review of the Literature

Fibrodysplasia ossificans progressiva (FOP) is a rare disease in which heterotopic ossification (HO) is formed in muscles, tendons and ligaments. Traumatic events, including surgery, are discouraged as this is known to trigger a flare-up with risk of subsequent HO. Anesthetic management for patients with FOP is challenging. Cervical spine fusion, ankylosis of the temporomandibular joints, thoracic insufficiency syndrome, restrictive chest wall disease, and sensitivity to oral trauma complicate airway management and anesthesia and pose life-threatening risks. We report a patient with FOP suffering from life-threatening antibiotic resistant bacterial infected ulcers of the right lower leg and foot. The anesthetic, surgical and postoperative challenges and considerations are discussed. In addition, the literature on limb surgeries of FOP patients is systemically reviewed. The 44 year-old female patient was scheduled for a through-knee amputation. Airway and pulmonary evaluation elicited severe abnormalities, rendering standard general anesthesia a rather complication-prone approach in this patient. Thus, regional anesthesia, supplemented with intravenous analgosedation and N₂O-inhalation were performed in this case. The surgery itself was securely planned to avoid any unnecessary tissue damage. Postoperatively the patient was closely monitored for FOP activity by ultrasound and [¹⁸F]PET/CT-scan. One year after surgery, a non-significant amount of HO had formed at the operated site. The systematic review revealed seventeen articles in which thirty-two limb surgeries in FOP patients were described. HO reoccurrence was described in 90% of the cases. Clinical improvement due to improved mobility of the operated joint was noted in 16% of the cases. It should be noted, though, that follow-up time was limited and no or inadequate imaging modalities were used to follow-up in the majority of these cases. To conclude, if medically urgent, limb surgery in FOP is possible even when general anesthesia is not preferred. The procedure should be well-planned, alternative techniques or procedures should be tested prior to surgery and special attention should be paid to the correct positioning of the patient. According to the literature recurrent HO should be expected after surgery of a limb, even though it was limited in the case described.

Collaboration Around Rare Bone Diseases Leads to the Unique Organizational Incentive of the Amsterdam Bone Center

In the field of rare bone diseases in particular, a broad care team of specialists embedded in multidisciplinary clinical and research environment is essential to generate new therapeutic solutions and approaches to care. Collaboration among clinical and research departments within a University Medical Center is often difficult to establish, and may be hindered by competition and non-equivalent cooperation inherent in a hierarchical structure. Here we describe the "collaborative organizational model" of the Amsterdam Bone Center (ABC), which emerged from and benefited the rare bone disease team. This team is often confronted with pathologically complex and under-investigated diseases. We describe the benefits of this model that still guarantees the autonomy of each team member, but combines and focuses our collective expertise on a clear shared goal, enabling us to capture synergistic and innovative opportunities for the patient, while avoiding self-interest and possible harmful competition.

Evolution of heterotopic bone in fibrodysplasia ossificans progressiva: An [18F]NaF PET/CT study

Fibrodysplasia ossificans progressiva (FOP) is a rare, autosomal dominant disorder characterized by heterotopic ossification (HO) in muscles, ligaments and tendons. Flare-ups often precede the formation of HO, resulting in immobilization of joints. Due to progression of the disease without signs of a flare-up, co-existence of a chronic progression of HO has been postulated, but conclusive evidence is lacking. Recently, it has been shown that [¹⁸F]NaF PET/CT is able to identify early ossifying disease activity during flare-ups. Therefore, the purpose of the present study was to assess whether [¹⁸F]NaF PET/CT might also be able to identify the possible presence of chronic progressive HO in FOP. A total of thirteen [¹⁸F]NaF PET/CT scans from five FOP patients were analysed. Scans were acquired over a period of 0.5 to 2 years. Volumes of HO and standardized uptake values (SUV) were obtained based on manual segmentation of CT images. SUV_peak values, defined as the average SUV value of a 1 mL sphere containing the hottest voxel pixels, were obtained. Two out of five patients experienced ≥1 active clinical flare-ups at the time of the [¹⁸F]NaF PET/CT scan. In addition, in four out of five patients, serial scans showed radiological progression of HO (3 to 8 cm³), as assessed by CT volume, in the absence of a clinical flare-up. This volumetric increase was present in 6/47 (12.8%) of identified HO structures and, in all cases, was accompanied by increased [¹⁸F]NaF uptake, with SUV_peak ranging from 8.4 to 17.9. In conclusion, HO may progress without signs of a flare-up. [¹⁸F]NaF PET/CT is able to identify these asymptomatic, but progressive HO lesions, thereby demonstrating the presence of chronic activity in FOP. Consequently, future drugs should not only target new HO formation, but also this chronic HO progression.

A Retrospective Cohort Study on Surgical Outcomes of Penile Prosthesis Implantation Surgery in Transgender Men After Phalloplasty

OBJECTIVES

To assess surgical outcomes of penile prosthesis implantation in transgender men who underwent phalloplasty.

PATIENTS AND METHODS

Transgender men who underwent penile prosthesis implantation after phalloplasty between January 1989 and September 2018 were retrospectively identified. A chart study was performed recording patient demographics, perioperative complications, and reoperations.

RESULTS

A total of 32 patients were identified: 22 underwent free radial forearm flap, 5 anterolateral thigh, 4 anterolateral thigh/free radial forearm flap, and 1 fibular flap phalloplasty. The median age at prosthesis implantation was 36 (range 21-59) years, the mean BMI 25.9 ± 4.0 kg/m². At first implantation, 16 inflatable (AMS Dynaflex (n = 13), AMS Ambicor (n = 3)) and 16 malleable (Coloplast genesis (n = 14), AMS Spectra (n = 2)) prostheses were placed. Of these, 5 (16%) were removed/replaced because of infection, 2 (6%) because of leakage, 2 because of extrusion, 2 because of dislocation, 2 because of dysfunction, and 1 (3%) because of pain. The postoperative course was completely uneventful in 10 (31.3%) patients. Of all implanted prostheses, including revision procedures (n = 45), 21 (44%) were surgically replaced or removed.

CONCLUSION

Prosthesis explantation, replacement, or revision surgery occurs frequently after penile prosthesis implantation. Patients need to be well-informed preoperatively on these complication rates.

Short-term cost-effectiveness of one-stage implant-based breast reconstruction with an acellular dermal matrix versus two-stage expander-implant reconstruction from a multicentre randomized clinical trial

Background

Implant‐based breast reconstruction (IBBR) is the most commonly performed reconstructive procedure and its economic impact is significant. This study aimed to analyse whether a direct one‐stage IBBR with use of an acellular dermal matrix (ADM) is more cost‐effective than two‐stage (expander‐implant) breast reconstruction.

Methods

The BRIOS (Breast Reconstruction In One Stage) study was an open‐label multicentre RCT in which women scheduled for skin‐sparing mastectomy and immediate IBBR were randomized between one‐stage IBBR with ADM or two‐stage IBBR. Duration of surgery and hospital stay, and visits for the primary surgery, unplanned and cosmetic procedures were recorded. Costs were estimated at an institutional level. Health status was assessed by means of the EuroQol Five Dimensions 5L questionnaire.

Results

Fifty‐nine patients (91 breasts) underwent one‐stage IBBR with ADM and 62 patients (92 breasts) two‐stage IBBR. The mean(s.d.) duration of surgery in the one‐stage group was significantly longer than that for two‐stage IBBR for unilateral (2·52(0·55) versus 2·02(0·35) h; P < 0·001) and bilateral (4·03(1·00) versus 3·25(0·58) h; P = 0·017) reconstructions. Costs were higher for one‐stage compared with two‐stage IBBR for both unilateral (€12 448 (95 per cent c.i. 10 722 to 14 387) versus €9871 (9373 to 10 445) respectively; P = 0·025) and bilateral (€16 939 (14 887 to 19 360) versus €13 383 (12 414 to 14 669); P = 0·002) reconstructions. This was partly related to the use of relatively expensive ADM. There was no difference in postoperative health status between the groups.

Conclusion

One‐stage IBBR with ADM was associated with higher costs, but similar health status, compared with conventional two‐stage IBBR. Registration number: NTR5446 ( http://www.trialregister.nl).

Quality of life and patient satisfaction after one-stage implant-based breast reconstruction with an acellular dermal matrix versus two-stage breast reconstruction (BRIOS): primary outcome of a randomised, controlled trial

BACKGROUND

There is increasing interest in the use of acellular dermal matrices (ADMs) in implant-based breast reconstruction (IBBR). Suggested advantages are that ADMs facilitate one-stage IBBR and improve aesthetic outcomes. We compared immediate one-stage ADM-assisted IBBR with two-stage IBBR (current standard of care). Our previously reported secondary endpoint showed that one-stage ADM-assisted IBBR was associated with significantly more adverse outcomes. Here, we present the primary endpoint results aiming to assess whether one-stage IBBR with ADM provides higher patient-reported quality of life (QOL) compared with two-stage IBBR.

METHODS

This multicentre, open-label, randomised controlled trial (BRIOS study) was done in eight hospitals in the Netherlands. We recruited women aged older than 18 years with breast carcinoma or a genetic predisposition who intended to undergo skin-sparing mastectomy and immediate IBBR. Participants were randomly assigned to undergo one-stage IBBR with ADM (Strattice, LifeCell, Branchburg, NJ, USA) or two-stage IBBR. Randomisation was stratified by centre and indication for surgery (oncological or prophylactic) in blocks of ten participants. The primary endpoint was patient-reported QOL, as measured with the BREAST-Q (ie, health-related QOL scales and satisfaction scales), in the modified intention-to-treat population. The study follow-up is complete. This study is registered with the Netherlands Trial Register, number NTR5446.

FINDINGS

Between April 14, 2013, and May 29, 2015, we enrolled 142 women, of whom 69 were randomly assigned to receive one-stage ADM-assisted IBBR and 73 to receive two-stage IBBR. After exclusions, the modified intention-to-treat population comprised 60 patients in the one-stage group and 61 patients in the two-stage group. Of these, 48 women (mean follow-up 17·0 months [SD 7·8]) in the one-stage group and 44 women (17·2 months [SD 6·7]) in the two-stage group completed the BREAST-Q at least 1 year after implant placement. We found no significant differences in postoperative patient-reported QOL domains, including physical wellbeing (one-stage mean 78·0 [SD 14·1] vs two-stage 79·3 [12·2], p=0·60), psychosocial wellbeing (72·6 [17·3] vs 72·8 [19·6], p=0·95), and sexual wellbeing (58·0 [17·0] vs 57·1 [19·5], p=0·82), or in the patient-reported satisfaction domains: satisfaction with breasts (63·4 [15·8] vs 60·3 [15·4], p=0·35) and satisfaction with outcome (72·8 [19·1] vs 67·8 [16·3], p=0·19).

INTERPRETATION

Taken together with our previously published findings, one-stage IBBR with ADM does not yield superior results in terms of patient-reported QOL compared with two-stage IBBR. Risks for adverse outcomes were significantly higher in the one-stage ADM group. Use of ADM for one-stage IBBM should be considered on a case-by-case basis.

FUNDING

Pink Ribbon, Nuts-Ohra, and LifeCell.

Symptomatic Neovaginal Candidiasis in Transgender Women After Penile Inversion Vaginoplasty: A Clinical Case Series of Five Consecutive Patients

Background: Vaginoplasty is performed as gender-affirming surgery in transgender women. While multiple surgical techniques exist for this goal, penile inversion vaginoplasty is performed most frequently. Neovaginal symptoms may impede sexual functioning after surgery.

Methods: A total of five consecutive patients with symptoms and positive swabs for neovaginal candida infection were described.

Results: All patients presented with white-colored neovaginal discharge and some with neovaginal itching and/or malodor. All were topically treated with miconazole, which resulted in symptom clearance. Follow-up swabs were negative for candida.

Conclusions: To our knowledge, this is the first report on (symptomatic) candidiasis of the penile-inverted neovagina.

Predictors of complications after direct-to-implant breast reconstruction with an acellular dermal matrix from a multicentre randomized clinical trial

BACKGROUND

In the multicentre randomized trial BRIOS (Breast Reconstruction In One Stage), direct-to-implant (DTI) breast reconstruction with an acellular dermal matrix (ADM) was associated with a markedly higher postoperative complication rate compared with two-stage tissue expander/implant breast reconstruction. This study aimed to identify factors that contribute to the occurrence of complications after DTI ADM-assisted breast reconstruction.

METHODS

Data were obtained from the BRIOS study, including all patients treated with DTI ADM-assisted breast reconstruction. Logistic regression analyses were performed to identify factors predictive of postoperative complications.

RESULTS

Fifty-nine patients (91 breasts) were included, of whom 27 (35 breasts) developed a surgical complication. Reoperations were performed in 29 breasts (32 per cent), with prosthesis removal in 22 (24 per cent). In multivariable analyses, mastectomy weight was associated with complications (odds ratio (OR) 1·94, 95 per cent c.i. 1·33 to 2·83), reoperations (OR 1·70, 1·12 to 2·59) and removal of the implant (OR 1·55, 1·11 to 2·17). Younger patients (OR 1·07, 1·01 to 1·13) and those who received adjuvant chemotherapy (OR 4·83, 1·15 to 20·24) more frequently required reoperation. In univariable analyses, adjuvant radiotherapy showed a trend towards more complications (OR 7·23, 0·75 to 69·95) and removal of the implant (OR 5·12, 0·76 to 34·44), without reaching statistical significance.

CONCLUSION

Breast size appeared to be the most significant predictor of complications in DTI ADM-assisted breast reconstruction. The technique should preferably be performed in patients with small to moderate sized breasts. Registration number: NTR5446 ( http://www.trialregister.nl).

Accuracy and reproducibility of fast fractional flow reserve computation from invasive coronary angiography

Fractional flow reserve (FFR) guided percutaneous coronary intervention (PCI) is associated with favourable outcome compared with revascularization based on angiographic stenosis severity alone. The feasibility of the new image-based quantitative flow ratio (QFR) assessed from 3D quantitative coronary angiography (QCA) and thrombolysis in myocardial infarction (TIMI) frame count using three different flow models has been reported recently. The aim of the current study was to assess the accuracy, and in particular, the reproducibility of these three QFR techniques when compared with invasive FFR. QFR was derived (1) from adenosine induced hyperaemic coronary angiography images (adenosine-flow QFR [aQFR]), (2) from non-hyperemic images (contrast-flow QFR [cQFR]) and (3) using a fixed empiric hyperaemic flow [fixed-flow QFR (fQFR)]. The three QFR values were calculated in 17 patients who prospectively underwent invasive FFR measurement in 20 vessels. Two independent observers performed the QFR analyses. Mean difference, standard deviation and 95% limits of agreement (LOA) between invasive FFR and aQFR, cQFR and fQFR for observer 1 were: 0.01 ± 0.04 (95% LOA: -0.07; 0.10), 0.01 ± 0.05 (95% LOA: -0.08; 0.10), 0.01 ± 0.04 (95% LOA: -0.06; 0.08) and for observer 2: 0.00 ± 0.03 (95% LOA: -0.06; 0.07), -0.01 ± 0.03 (95% LOA: -0.07; 0.05), 0.00 ± 0.03 (95% LOA: -0.06; 0.05). Values between the 2 observers were (to assess reproducibility) for aQFR: 0.01 ± 0.04 (95% LOA: -0.07; 0.09), for cQFR: 0.02 ± 0.04 (95% LOA: -0.06; 0.09) and for fQFR: 0.01 ± 0.05 (95% LOA: -0.07; 0.10). In a small number of patients we showed good accuracy of three QFR techniques (aQFR, cQFR and fQFR) to predict invasive FFR. Furthermore, good inter-observer agreement of the QFR values was observed between two independent observers.

Double flap phalloplasty in transgender men: Surgical technique and outcome of pedicled anterolateral thigh flap phalloplasty combined with radial forearm free flap urethral reconstruction

Introduction

Radial forearm free flap (RFFF) tube‐in‐tube phalloplasty is the most performed phalloplasty technique worldwide. The conspicuous donor‐site scar is a drawback for some transgender men. In search for techniques with less conspicuous donor‐sites, we performed a series of one‐stage pedicled anterolateral thigh flap (ALT) phalloplasties combined with RFFF urethral reconstruction. In this study, we aim to describe this technique and assess its surgical outcome in a series of transgender men.

Patients and Methods

Between January 2008 and December 2015, nineteen transgender men (median age 37, range 21–57) underwent pedicled ALT phalloplasty combined with RFFF urethral reconstruction in one stage. The surgical procedure was described. Patient demographics, surgical characteristics, intra‐ and postoperative complications, hospitalization length, and reoperations were recorded.

Results

The size of the ALT flaps ranged from 12 × 12 to 15 × 13 cm, the size of the RFFFs from 14 × 3 to 17 × 3 cm. Median clinical follow‐up was 35 months (range 3–95). Total RFFF failure occurred in two patients, total ALT flap failure in one patient, and partial necrosis of the ALT flap in one patient. Long‐term urinary complications occurred in 10 (53%) patients, of which 9 concerned urethral strictures.

Conclusions

In experienced hands, one‐stage pedicled ALT phalloplasty combined with RFFF urethral reconstruction is a feasible alternative surgical option in eligible transgender men, who desire a less conspicuous forearm scar. Possible drawbacks comprise flap‐related complications, difficult inner flap monitoring and urethral complications.

Two-stage implant-based breast reconstruction compared with immediate one-stage implant-based breast reconstruction augmented with an acellular dermal matrix: an open-label, phase 4, multicentre, randomised, controlled trial

BACKGROUND

The evidence justifying the use of acellular dermal matrices (ADMs) in implant-based breast reconstruction (IBBR) is limited. We did a prospective randomised trial to compare the safety of IBBR with an ADM immediately after mastectomy with that of two-stage IBBR.

METHODS

We did an open-label, randomised, controlled trial in eight hospitals in the Netherlands. Eligible women were older than 18 years with breast carcinoma or a gene mutation linked with breast cancer who intended to undergo skin-sparing mastectomy and immediate IBBR. Randomisation was done electronically, stratified per centre and in blocks of ten to achieve roughly balanced groups. Women were assigned to undergo one-stage IBBR with ADM (Strattice, LifeCell, Branchburg, NJ, USA) or two-stage IBBR. The primary endpoint was quality of life and safety was assessed by the occurrence of adverse outcomes. Analyses were done per protocol with logistic regression and generalised estimating equations. This study is registered at Nederlands Trial Register, number NTR5446.

FINDINGS

142 women were enrolled between April 14, 2013, and May 29, 2015, of whom 59 (91 breasts) in the one-stage IBBR with ADM group and 62 (92 breasts) in the two-stage IBBR group were included in analyses. One-stage IBBR with ADM was associated with significantly higher risk per breast of surgical complications (crude odds ratio 3·81, 95% CI 2·67-5·43, p<0·001), reoperation (3·38, 2·10-5·45, p<0·001), and removal of implant, ADM, or both (8·80, 8·24-9·40, p<0·001) than two-stage IBBR. Severe (grade 3) adverse events occurred in 26 (29%) of 91 breasts in the one-stage IBBR with ADM group and in five (5%) of 92 in the two-stage IBBR group. The frequency of mild to moderate adverse events was similar in the two groups.

INTERPRETATION

Immediate one-stage IBBR with ADM was associated with adverse events and should be considered very carefully. Understanding of selection of patients, risk factors, and surgical and postsurgical procedures needs to be improved.

FUNDING

Pink Ribbon, Nuts-Ohra, and LifeCell.

Autologous Fat Grafting in Cosmetic Breast Augmentation: A Systematic Review on Radiological Safety, Complications, Volume Retention, and Patient/Surgeon Satisfaction

BACKGROUND

Autologous fat grafting (AFG) is increasingly used in cosmetic surgery. However, its efficacy and safety are still ambiguous. Both a comprehensive overview and recapitulation of the relevant literature provide current evidence on the efficacy and outcomes of AFG in cosmetic breast surgery.

OBJECTIVES

This review provides an up-to-date overview of the literature on AFG in cosmetic breast augmentation.

METHODS

A systematic review of the literature on AFG used for cosmetic breast augmentation was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. This study included selected studies that were published between January 1996 and February 2016 and reported on 10 patients or more who had a minimal mean follow-up period of 1 year.

RESULTS

In this study, 22 articles that reported on 3565 patients with follow-up periods ranging from 12 to 136 months were included. A complication rate of 17.2% (95% CI 15.9-18.5) was seen. Indurations were the most frequent complication (33.3%, 95% CI 20.4-46.3), followed by persistent pain (25%, 95% CI 0.5-49.5), and hematoma (16.4%, 95% CI 14.5-18.4). Mammograms revealed micro-calcifications (9.0%, 95% CI 6.4-11.5) and macro-calcifications (7.0%, 95% CI 3.8-10.2). The mean volume retention was 62.4% (range, 44.7-82.6%), with a satisfaction rate of 92% in patients and 89% in surgeons.

CONCLUSIONS

AFG is a promising method in achieving autologous cosmetic breast augmentation with satisfactory volume retention and satisfaction rates in eight and six studies, respectively. Complications and radiological findings are comparable to those after implant augmentation. Future studies should focus on cancer occurrence and detection to further substantiate AFG safety. In addition, grafting methods and the use of auxiliary procedures to identify factors leading to better outcomes in terms of volume retention should be investigated. Finally, objective questionnaires are needed to represent patient satisfaction.

LEVEL OF EVIDENCE

3 Therapeutic.

Body Image in Transmen: Multidimensional Measurement and the Effects of Mastectomy

INTRODUCTION

Transmen are generally dissatisfied with their breasts and often opt for mastectomy. However, little is known about the specific effects of this procedure on this group's body image.

AIM

To prospectively assess the effect of mastectomy on the body image of transmen, including cognitive, emotional, and behavioral aspects.

METHODS

During a 10-month period, all transmen applying for mastectomy were invited to participate in this study. The 33 participants completed assessments preoperatively and at least 6 months postoperatively.

MAIN OUTCOME MEASURES

Participants were surveyed on body satisfaction (Body Image Scale for Transsexuals), body attitudes (Multidimensional Body-Self Relations Questionnaire), appearance schemas (Appearance Schemas Inventory), situational bodily feelings (Situational Inventory of Body Image Dysphoria), body image-related quality of life (Body Image Quality of Life Inventory), and self-esteem (Rosenberg Self-Esteem Scale). Control values were retrieved from the literature and a college sample.

RESULTS

Before surgery, transmen reported less positive body attitudes and satisfaction, a lower self-esteem and body image-related quality of life compared with cisgender men and women. Mastectomy improved body satisfaction most strongly, although respondents reported improvements in all domains (eg, decreased dysphoria when looking in the mirror and improved feelings of self-worth). Most outcome measurements were strongly correlated.

CONCLUSION

Mastectomy improves body image beyond satisfaction with chest appearance alone. Body satisfaction and feelings of "passing" in social situations are associated with a higher quality of life and self-esteem.

The effect of continuous enteral tube feeding on various nutritional parameters in patients with disseminated malignant melanoma during intensive chemotherapy

In a prospective study the effect of continuous enteral tube feeding was evaluated on various nutritional parameters in patients with disseminated malignant melanoma during 13 chemotherapy courses employing bleomycin, DTIC, vindesine and actinomycin D. The patients received a quantity of calories according to their pretreatment intake, but complete metabolic equilibrium could not be obtained during chemotherapy. Although the weight/height index remained unchanged, a decrease of serum albumin and prealbumin level occurred during all 13 treatment courses. Transferrin level decreased during 11 of these courses and cholinesterase level during 12. Triceps skinfold thickness and arm muscle circumference diminished equally. Serum prealbumin was the first nutritional parameter to fall during chemotherapy and seems to be a very sensitive indicator of the occurrence of nutritional imbalance. The plasma vitamin C level was low before treatment while during treatment both vitamin C and vitamin A level fell quickly even though the nutritional intake of these vitamins was adequate. We conclude that continuous enteral tube feeding, which is a feasible method of feeding, can to some extent fulfill the nutritional needs of patients treated with intensive chemotherapy.

Randomised Phase III study of biweekly 24-h infusion of high-dose 5FU with folinic acid and oxaliplatin versus monthly plus 5-FU/folinic acid in first-line treatment of advanced colorectal cancer

BACKGROUND

A phase III study was started to compare oxaliplatin/5FU/LV in the first-line with bolus FU/LV in metastatic colorectal cancer.

PATIENTS AND METHODS

302 patients were randomised and received bolus 5-FU 425 mg/m(2) day 1-5, FA 20 mg/m(2) day 1-5, q 4 wk or oxaliplatin 85 mg/m(2), 2 h-infusion, FA 200 mg/m(2), 1-h infusion. 5-FU 2600 mg/m(2), 24-h infusion day 1, q 2 wk. The primary endpoint was response rate (RR).

RESULTS

The median follow-up is 31.8 months, 90.4% of the patients have died. Confirmed RR, progression free survival (PFS; months) and median overall survival (OS; months) in 5FU/LV versus 5FU/LV/oxaliplatin were respectively 18.5% versus (vs) 33.8% (P = 0.004), 5.6 vs 6.7 (P = 0.016) and 13.3 vs 13.8 (P = 0.619). In the 5FU/LV/oxaliplatin arm less grade (3/4) toxicity was measured for diarrhoea, stomatitis, an increase in idiosyncratic side effects and neurosensory events compared with 5FU/LV. The quality of life (QOL) was equal in both arms. Second line treatment was given in 62% of the patients, crossover of 5FU/LV to 5FU/LV/oxaliplatin occurred in 14%.

CONCLUSIONS

Oxaliplatin in the first-line resulted in an increased RR and PFS with less grade 3/4 mucositis/diarrhoea compared with 5FU/LV alone. Idiosyncratic side effects deserve attention with oxaliplatin. Despite a low treatment cross over rate, OS in both groups was comparable.

Pulsed dye laser treatment, a review of indications and outcome based on published trials

INTRODUCTION

Pulsed dye laser (PDL) treatment is based on the principle of selective photothermolysis and is widely considered to be the treatment of choice for a variety of cutaneous vascular lesions.

OBJECTIVE

To review the indications and outcome of PDL treatment and summarise new developments.

METHOD

A literature-based study has been conducted entailing the review of publications over the period January 1993-December 2003 using the databases Medline and Cochrane CENTRAL.

RESULTS

The PDL was found to be effective in port wine stain, facial telangiectasia, leg telangiectasia <0.5 mm, scars, hypertrophic scars and ulcerated haemangioma.

DISCUSSION

Essential characteristics of lesions suitable for PDL treatment are discussed and guidelines are presented for future research.

A phase I/II and pharmacokinetic study of irinotecan in combination with capecitabine as first-line therapy for advanced colorectal cancer

PURPOSE

The aim of this study was to determine in patients with previously untreated advanced colorectal cancer the maximum tolerated dose (MTD) and safety profile of irinotecan in combination with capecitabine, to identify a recommended dose and to determine the response rate and time to disease progression. In addition, we aimed to explore the pharmacokinetic parameters of irinotecan and capecitabine when used in different sequences of administration, with irinotecan infusion either prior to or after the first intake of capecitabine.

PATIENTS AND METHODS

One hundred patients were included: 43 patients were recruited into an extended phase I trial of alternating escalation in dose of both drugs where irinotecan was administered intravenously (i.v) on day 1 after first intake of capecitabine taken from days 1-14 twice daily, with cycles repeated every 3 weeks. After the determination of recommended dose a further 57 patients were treated in a phase II evaluation with the reverse sequence of drugs on day 1. Pharmacokinetic analysis was performed in patients treated at the recommended dose in two cohorts of patients in which the sequence of the first administration of each drug was reversed.

RESULTS

The MTD of the combination was determined as irinotecan 300 mg/m2, with capecitabine 2000 mg/m2/day. Dose limiting toxicities were neutropenia and diarrhoea. The recommended dose is irinotecan intravenous (i.v.) 250 mg/m2 day 1 and capecitabine 2000 mg/m2/day days 1-14, every 3 weeks. Treatment was well tolerated, with diarrhoea the most common serious toxicity. Response rate in the phase II cohort was 42% [95% confidence interval (CI) 29% to 56%]. Median duration of response was 7.7 months (95% CI 7.5-8.9). Median time to progression was 8.3 months (95% CI 5.8-10). No significant effect on irinotecan pharmacokinetics was observed whatever the intake of capecitabine before or after irinotecan infusion. An effect of irinotecan on capecitabine and some capecitabine metabolites was observed, but irinotecan did not effect 5-fluorouracil (5-FU) pharmacokinetics.

CONCLUSIONS

Irinotecan in combination with capecitabine is a well tolerated regimen with an activity comparable to, but more convenient than, irinotecan-5-FU i.v. combinations in patients with previously untreated advanced colorectal cancer. The pharmacokinetic data suggest that the sequence of administration does not impact significantly on the metabolism of the two drugs.

A phase II study of raltitrexed and gemcitabine in patients with advanced pancreatic carcinoma

Advanced adenocarcinoma of the pancreas has a very poor prognosis. The aim of this study was to assess the efficacy and tolerability of a combination of the chemotherapeutic agents gemcitabine and raltitrexed. Chemonaïve patients with advanced adenocarcinoma of the pancreas were treated with a combination of raltitrexed (3.5 mg m⁻² on day 1 of a 21-day treatment cycle) and gemcitabine (800 mg m⁻² intravenously (i.v.) on days 1 and 8 of a 21-day cycle). Between April 2000 and February 2003, 27 patients were enrolled onto the study. The mean duration of treatment was 11 weeks. Four of 27 patients experienced at least one episode of grade 3 or 4 neutropenia. One patient with grade 4 neutropenia died due to sepsis. Four of 27 patients experienced grade 4 diarrhoea. There was one partial remission (4%) and 12 patients experienced disease stabilisation (44%). The 6-month and 1-year survival rates were 37 and 11%, respectively. Symptomatic benefit occurred in seven (26%) patients. We conclude that a combination of raltitrexed and gemcitabine, using the schedule and doses in this study, cannot be recommended for patients with advanced pancreatic cancer.

Comparison of TTS-fentanyl with sustained-release oral morphine in the treatment of patients not using opioids for mild-to-moderate pain

OBJECTIVE

This randomised, multicentre, direct open comparative trial evaluated the efficacy, treatment convenience, tolerability and safety aspects of transdermal therapeutic system (TTS)-fentanyl and sustained-release oral morphine (SRM) in both opioid-naïve patients with moderate-to-severe cancer-related pain and in patients who had already been using opioids for mild-to-moderate pain. The two treatment groups were run in parallel. Special attention was paid to constipation, nausea/vomiting, drowsiness and respiratory depression.

PATIENTS AND METHODS

The 131 enrolled patients started the 4-week treatment at low doses of opioid (25 microg/h TTS-fentanyl for 3 days or 30 mg SRM every 12 h) and were individually titrated. Tolerability, efficacy and safety were assessed throughout the study period. Frequency of constipation was the primary study variable and accordingly the study was powered for this. Both patients and investigators made a global treatment evaluation.

RESULTS

TTS-fentanyl and SRM were shown to be equally effective. Pain control and sleep quality improved with both treatments. None of the patients developed respiratory depression. Statistically significantly more patients in the SRM treatment group discontinued the trial prematurely (59% vs 27%; p < 0.001), particularly due to adverse events (36% vs 4%; p < 0.001). Fewer patients in the TTS-fentanyl than in the SRM treatment group reported constipation during the trial. This finding was statistically significant after 1 week of treatment (27% vs 57%; p = 0.003). The favourable tolerability profile of TTS-fentanyl was also reflected in both the patient and the investigator global evaluation of the treatment. Patient assessment favoured TTS-fentanyl treatment in terms of a significantly lower rate of troublesome side-effects ('quite a bit' to 'very much' troublesome side-effects in 14% vs 36% of patients; p = 0.003) and less interruption of daily activities (absence of any interruption of daily activities in 88% vs 63% of patients; p = 0.012). Investigators scored TTS-fentanyl as significantly better with respect to 'side-effects' (p = 0.039) and 'overall impression' (p = 0.013). Sub-analyses of opioid-naïve users gave similar results.

CONCLUSION

These data indicate that TTS-fentanyl, when used as an opioid of first choice in the treatment of cancer-related pain, is as effective as, but better tolerated than, SRM, including in opioid-naïve patients.

A double-blind, randomized comparison of omeprazole Multiple Unit Pellet System (MUPS) 20 mg, lansoprazole 30 mg and pantoprazole 40 mg in symptomatic reflux oesophagitis followed by 3 months of omeprazole MUPS maintenance treatment: a Dutch multicentre trial

BACKGROUND

Proton pump inhibitors (PPIs) have proved to be effective in treating reflux oesophagitis. Until now, no study had compared the PPIs omeprazole Multiple Unit Pellet System (MUPS), lansoprazole and pantoprazole in patients with reflux oesophagitis.

AIM

To compare omeprazole MUPS 20 mg, lansoprazole 30 mg and pantoprazole 40 mg for treatment effect in symptomatic reflux oesophagitis.

METHOD

Patients with grade I-IV symptomatic reflux oesophagitis were randomized to double-blind omeprazole 20 mg once morning, lansoprazole 30 mg o.m. or pantoprazole 40 mg o.m. Patient satisfaction and symptoms were evaluated after 4 and 8 weeks. Patients not satisfied after 8 weeks were treated for another 4 weeks with omeprazole 40 mg MUPS (open). Successful treatment was followed by 3 months' maintenance treatment with omeprazole MUPS 20 mg (patients satisfied after 4 or 8 weeks) or omeprazole MUPS 40 mg (patients satisfied after 12 weeks).

RESULTS

On intention-to-treat (ITT) analysis (n = 461) at 4 and 8 weeks, respectively, 84% and 87% (omeprazole MUPS), 78% and 81% (lansoprazole), and 84% and 89% (pantoprazole) were free of heartburn. Equivalence was found between omeprazole MUPS and pantoprazole (heartburn relief), but not with lansoprazole. Patient satisfaction after 4 and 8 weeks, respectively, was 79% and 89% (omeprazole MUPS), 76% and 86% (lansoprazole), and 79% and 91% (pantoprazole). Patient satisfaction was similar in all treatment groups. During maintenance, 87% in the omeprazole MUPS 20 mg group and 81% in the omeprazole MUPS 40 mg group were satisfied after 3 months.

CONCLUSIONS

Omeprazole MUPS 20 mg and pantoprazole 40 mg have equivalent efficacy in the treatment of reflux oesophagitis. Based on patient satisfaction, omeprazole MUPS 20 mg, lansoprazole 30 mg and pantoprazole 40 mg are equally effective.

PE2 cleavage mutants of Sindbis virus: correlation between viral infectivity and pH-dependent membrane fusion activation of the spike heterodimer

The spike glycoprotein E2 of Sindbis virus (SIN) is synthesized in the infected cell as a PE2 precursor protein, which matures through cleavage by a cellular furin-like protease. Previous work has shown that SIN mutants impaired in PE2 cleavage are noninfectious on BHK-21 cells, the block in infection being localized at a step after virus-receptor interaction but prior to RNA replication. Here, we studied the membrane fusion properties of SIN PE2 cleavage mutants and observed that these viruses are impaired in their ability to form an E1 homotrimer and to fuse with liposomes at a mildly acidic pH. The block in spike rearrangement and fusion could be overridden by exposure of the mutant viruses to very low pH (<4.5). Cleavage mutants with second-site resuscitating mutations in PE2 were highly infectious for BHK-21 cells. The ability of these viruses to form E1 homotrimers and to fuse at a mildly acidic pH was completely restored despite a sustained lack of PE2 cleavage.

Deacylation of the transmembrane domains of Sindbis virus envelope glycoproteins E1 and E2 does not affect low-pH-induced viral membrane fusion activity

The envelope glycoproteins E1 and E2 of Sindbis virus are palmitoylated at cysteine residues within their transmembrane domains (E1 at position 430, and E2 at positions 388 and 390). Here, we investigated the in vitro membrane fusion activity of Sindbis virus variants (derived from the Toto 1101 infectious clone), in which the E1 C430 and/or E2 C388/390 residues had been substituted for alanines. Both the E1 and E2 mutant viruses, as well as a triple mutant virus, fused with liposomes in a strictly low-pH-dependent manner, the fusion characteristics being indistinguishable from those of the parent Toto 1101 virus. These results demonstrate that acylation of the transmembrane domain of Sindbis virus E1 and E2 is not required for expression of viral membrane fusion activity.

Low-pH-dependent fusion of Sindbis virus with receptor-free cholesterol- and sphingolipid-containing liposomes

There is controversy as to whether the cell entry mechanism of Sindbis virus (SIN) involves direct fusion of the viral envelope with the plasma membrane at neutral pH or uptake by receptor-mediated endocytosis and subsequent low-pH-induced fusion from within acidic endosomes. Here, we studied the membrane fusion activity of SIN in a liposomal model system. Fusion was followed fluorometrically by monitoring the dilution of pyrene-labeled lipids from biosynthetically labeled virus into unlabeled liposomes or from labeled liposomes into unlabeled virus. Fusion was also assessed on the basis of degradation of the viral core protein by trypsin encapsulated in the liposomes. SIN fused efficiently with receptor-free liposomes, consisting of phospholipids and cholesterol, indicating that receptor interaction is not a mechanistic requirement for fusion of the virus. Fusion was optimal at pH 5.0, with a threshold at pH 6.0, and undetectable at neutral pH, supporting a cell entry mechanism of SIN involving fusion from within acidic endosomes. Under optimal conditions, 60 to 85% of the virus fused, depending on the assay used, corresponding to all of the virus bound to the liposomes as assessed in a direct binding assay. Preincubation of the virus alone at pH 5.0 resulted in a rapid loss of fusion capacity. Fusion of SIN required the presence of both cholesterol and sphingolipid in the target liposomes, cholesterol being primarily involved in low-pH-induced virus-liposome binding and the sphingolipid catalyzing the fusion process itself. Under low-pH conditions, the E2/E1 heterodimeric envelope glycoprotein of the virus dissociated, with formation of a trypsin-resistant E1 homotrimer, which kinetically preceded the fusion reaction, thus suggesting that the E1 trimer represents the fusion-active conformation of the viral spike.

Steady-state pharmacokinetics and sputum penetration of lomefloxacin in patients with chronic obstructive pulmonary disease and acute respiratory tract infections

Oral doses of 400 mg of lomefloxacin were administered once daily prior to breakfast to 10 middle-aged to elderly hospitalized patients with chronic obstructive pulmonary disease during treatment for bronchopulmonary infections. Serial plasma and sputum samples and fractional urine samples were obtained over a steady-state dosing interval. Lomefloxacin concentrations were determined in duplicate by a validated agar well diffusion microbiological assay. The maximum plasma lomefloxacin concentration (4.5 +/- 1.8 mg/liter), the time of occurrence of the maximum concentration (1.7 +/- 1.6 h), and the apparent volume of distribution associated with the terminal phase (2.19 +/- 1.05 liter/kg) were comparable to the values reported for healthy, young volunteers. Compared with the data reported for young adults, the elimination half-life (12.7 +/- 4.67 h) was longer and the apparent total body clearance (132 +/- 36.6 ml/min/1.73 m2) was lower in middle-aged to elderly patients. These differences were most likely attributable to age-related decreases in renal function, as evidenced by the lower lomefloxacin renal clearance (70.3 +/- 33.5 ml/min) in patients. The presence of acute respiratory infection per se did not appear to alter lomefloxacin pharmacokinetics. The peak lomefloxacin concentration in purulent, expectorated sputum samples of 4.3 +/- 1.2 mg/liter occurred 3.1 +/- 1.7 h after dose administration and subsequently declined to 1.7 +/- 0.5 mg/liter at the end of the 24-h dosing interval. The percent penetration into sputum, as assessed by comparing the area under the curve for sputum and plasma samples, was 120 +/- 39.8 (range, 70 to 185). The steady-state lomefloxacin concentrations in plasma and sputum samples from ill, older patients were in excess of the MICs for 90% of the strains tested of common, susceptible respiratory pathogens over most of the dosing interval.

A quasi steady state ramp method for the estimation of the ventilatory response to CO2

There are two suitable methods for estimating the ventilatory response to CO2: the steady state or the Read method. The latter is usually applied because of its shorter duration and its stimulus, near to tissue PCO2. From recent studies on a physiological model but also on the dynamics of the ventilatory CO2 response (G liters min-1 kPa-1), it can be shown, both theoretically and experimentally, that the Read method markedly overestimates the steady-state estimate of the ventilatory CO2 response (Gss). We have, therefore, applied two ramp approaches: one with an initial end-tidal PCO2 (PetCO2) step of 0.5 kPa and a mean PetCO2 ramp slope of 0.41 kPa/min (step-ramp method, SR) and one without an initial step and a mean ramp slope of 0.21 kPa/min (ramp method; R). As predicted by theory, the ventilatory CO2 response from the R method (GR) during the second 4-min interval of the 8-min procedure and the ventilatory CO2 response from the SR method (GSR) from the whole 6-min procedure, except for the first 30 s, should yield a good approximation of Gss. In a group of 12 normal volunteers we indeed found no differences between these estimates, and, as predicted by theory, we found both estimates to be larger than GR from the first 4-min interval. From the interindividual spread, only the difference with respect to GSR was significant (p less than 0.02). The volunteers preferred the R approach because of the lower PetCO2 attained and the smaller ventilation increase.(ABSTRACT TRUNCATED AT 250 WORDS)