A Second Drain Decreases Seroma Formation in Prepectoral Immediate Breast Reconstruction with an Acellular Dermal Matrix

Seroma formation is the most common complication after mastectomy. While the exact pathophysiology behind seroma development has not been entirely elucidated, seromas are associated with negative outcomes in breast reconstruction. The utilization of drains is one method to combat seroma. However, the current state of plastic surgery is divided as to whether one drain or two drains is optimal in reducing seroma formation. We hypothesized that using two drains instead of one drain would reduce the risk of seroma more so than one drain.

METHODS

This was a retrospective cohort study of patients who underwent prepectoral direct to implant reconstruction at a single institution by a single surgeon. Each patient underwent reconstruction with either one or two drains. Patients were followed postoperatively for rates of seroma formation. Seroma were classified as either minor or major. Secondary variables including drain duration, infection, and necrosis were also analyzed.

RESULTS

A total of 99 breasts and 71 patients experienced breast reconstruction with two drains, and 163 breasts corresponding to 135 patients received reconstruction with one drain. In the two drain cohort, 14 (14.1%) developed a seroma, with 11 (11.1%) being minor seromas and three (3.03%) being major seromas. In comparison, out of the one drain cohort, 41 (25.2%) developed a seroma, with 35 (21.5%) being a minor seroma and six (3.68%) being classified as major.

CONCLUSION

This study suggests that two drains decreases the rate and risk of seroma formation compared to one drain in prepectoral breast reconstruction with an acellular dermal matrix.

Use of New Technologies in Implant-Based Breast Reconstruction

Outcomes after mastectomy and prosthetic-based breast reconstruction have improved immensely since the development of the first tissue expander and breast implant in the 1960s. One major factor contributing to our improved outcomes over the past two decades is the increasing availability and improvement of perfusion assessment technology. Instrumental methods now exist which allow surgeons to assess tissue viability intraoperatively, and provide actionable, objective data that augments clinical assessment. In this article, the authors detail two commercially available, state-of-the-art technologies that surgeons may use to assist in mastectomy flap assessment and facilitate the reconstructive process.

Pyopericardium secondary to achalasia-associated squamous cell carcinoma of the oesophagus

Patients with achalasia of the oesophagus are known to be at increased risk of oesophageal squamous cell carcinoma. To our knowledge, this is the first report of an achalasia-associated oesophageal squamous cell carcinoma presenting with acute sepsis secondary to pyopericardium.

Developing and assessing the utility of a You-Tube based clinical genetics video channel for families affected by inherited tumours

We have designed and implemented the first worldwide You Tube channel with 22 videos covering common questions asked in familial cancer susceptibility clinics. We discuss the use of the videos including demographics of registered You Tube users, and what lessons have been learnt about how the general public uses medical information online. The most popular video on inheritance patterns has been watched on average 84 times per month. The mostly highly viewed videos include inheritance patterns, breast cancer screening and hereditary non-polyposis colorectal cancer. Registered viewers were more commonly male and the average age of the registered user was 45-54 years; similar to that seen in Genetics Clinics suggesting that age may not be a major barrier to access to this type of information for patients. The videos have been viewed in more than 140 countries confirming that there is clearly an audience for this type of information. Patient feedback questionnaires indicate that these videos provide a useful aide memoir for the clinic appointment, and most people would recommend them to others. In summary, You Tube videos are easy and cost effective to make. They have the ability to disseminate genetics education to a worldwide audience and may be a useful adjunct to clinical appointments.

Podoplanin mediates ECM degradation by squamous carcinoma cells through control of invadopodia stability

Invadopodia are actin-rich cell membrane projections used by invasive cells to penetrate the basement membrane. Control of invadopodia stability is critical for efficient degradation of the extracellular matrix (ECM); however, the underlying molecular mechanisms remain poorly understood. Here, we uncover a new role for podoplanin, a transmembrane glycoprotein closely associated with malignant progression of squamous cell carcinomas (SCCs), in the regulation of invadopodia-mediated matrix degradation. Podoplanin downregulation in SCC cells impairs invadopodia stability, thereby reducing the efficiency of ECM degradation. We report podoplanin as a novel component of invadopodia-associated adhesion rings, where it clusters prior to matrix degradation. Early podoplanin recruitment to invadopodia is dependent on lipid rafts, whereas ezrin/moesin proteins mediate podoplanin ring assembly. Finally, we demonstrate that podoplanin regulates invadopodia maturation by acting upstream of the ROCK-LIMK-Cofilin pathway through the control of RhoC GTPase activity. Thus, podoplanin has a key role in the regulation of invadopodia function in SCC cells, controlling the initial steps of cancer cell invasion.

Intraoperative laser angiography using the SPY system: review of the literature and recommendations for use

Inadequate tissue perfusion is a key contributor to early complications following reconstructive procedures. Accurate and reliable intraoperative evaluation of tissue perfusion is critical to reduce complications and improve clinical outcomes. Clinical judgment is the most commonly used method for evaluating blood supply, but when used alone, is not always completely reliable. A variety of other methodologies have been evaluated, including Doppler devices, tissue oximetry, and fluorescein, among others. However, none have achieved widespread acceptance. Recently, intraoperative laser angiography using indocyanine green was introduced to reconstructive surgery. This vascular imaging technology provides real-time assessment of tissue perfusion that correlates with clinical outcomes and can be used to guide surgical decision making. Although this technology has been used for decades in other areas, surgeons may not be aware of its utility for perfusion assessment in reconstructive surgery. A group of experts with extensive experience with intraoperative laser angiography convened to identify key issues in perfusion assessment, review available methodologies, and produce initial recommendations for the use of this technology in reconstructive procedures.

PAK4 kinase activity and somatic mutation promote carcinoma cell motility and influence inhibitor sensitivity

Hepatocyte growth factor (HGF) and its receptor (c-Met) are associated with cancer cell motility and invasiveness. p21-activated kinase 4 (PAK4), a potential therapeutic target, is recruited to and activated by c-Met. In response, PAK4 phosphorylates LIM kinase 1 (LIMK1) in an HGF-dependent manner in metastatic prostate carcinoma cells. PAK4 overexpression is known to induce increased cell migration speed but the requirement for kinase activity has not been established. We have used a panel of PAK4 truncations and mutations in a combination of over-expression and RNAi rescue experiments to determine the requirement for PAK4 kinase activity during carcinoma cell motility downstream of HGF. We find that neither the kinase domain alone nor a PAK4 mutant unable to bind Cdc42 is able to fully rescue cell motility in a PAK4-deficient background. Nevertheless, we find that PAK4 kinase activity and associated LIMK1 activity are essential for carcinoma cell motility, highlighting PAK4 as a potential anti-metastatic therapeutic target. We also show here that overexpression of PAK4 harboring a somatic mutation, E329K, increased the HGF-driven motility of metastatic prostate carcinoma cells. E329 lies within the G-loop region of the kinase. Our data suggest E329K mutation leads to a modest increase in kinase activity conferring resistance to competitive ATP inhibitors in addition to promoting cell migration. The existence of such a mutation may have implications for the development of PAK4-specific competitive ATP inhibitors should PAK4 be further explored for clinical inhibition.

Increased use of laparoscopy in acute right iliac fossa pain - is it good for patients?

AIM

The use of laparoscopy, with or without appendicectomy, is becoming more common in the management of acute right iliac fossa (RIF) pain, but little is known of the 'unintended' consequences of this change. This study aimed to evaluate the impact of increased use of laparoscopy on the number and type of patients treated surgically and on the rate of negative appendicectomy.

METHOD

A prospective audit was carried out of admissions to a teaching hospital over two, 3-month periods during 2007 and 2008. The management, investigations and outcome of patients presenting with RIF pain were studied.

RESULTS

Admissions were stable over the two time-periods. There was a significant increase in the number of laparoscopic operations performed, from 22.5% (14/62) in 2007 to 85.7% (72/84) in 2008 (P < 0.0001), and the percentage of patients undergoing surgery rose from 55.4% (n = 62) in 2007 to 71.2% (n = 84) in 2008 (P < 0.01). In 2008, female patients were more likely to have surgery, an increase from 37.1% to 66.2% (P < 0.001), and were more likely to have a laparoscopic procedure, an increase from 50% to 98% (P < 0.0001). The rate of histologically confirmed appendicitis did not increase significantly (50/122 vs 57/118; P = 0.25), but the number of patients with a normal appendix either left in situ because it was macroscopically normal or found to be histologically normal following excision, increased significantly, from 9.01% in 2007 to 21.2% in 2008 (P < 0.01). The diagnostic value of pelvic ultrasound decreased from 75.6% of examinations in 2007 to 54.5% in 2008 (P = 0.039).

CONCLUSION

An increase in laparoscopic procedures has resulted in more operations in women, an associated higher negative appendicectomy rate and decreased usefulness of pelvic ultrasound. Increased use of laparoscopy needs to be balanced against the diagnostic benefits of 'negative' laparoscopy.

Microbial iron reduction by enrichment cultures isolated from estuarine sediments

Microbial Fe reduction in acetate- and succinate-containing enrichment cultures initiated with an estuarine sediment inoculum was studied. Fe reduction was unaffected when SO(4) reduction was inhibited by MoO(4), indicating that both processes could occur independently. Bacterially produced sulfide precipitated as FeS but was not completely responsible for Fe reduction. The separation of oxidized Fe particles from bacteria by dialysis tubing demonstrated that direct bacterial contact was necessary for Fe reduction. Fe reduction in cultures amended with NO(3) was delayed until NO(3) and NO(2) were removed. However, bacterial attachment to oxidized Fe particles in NO(3)-amended cultures occurred early during growth in a manner similar to NO(3)-free cultures. During late stages of growth, bacteria not attached to Fe particles became pale and swollen, while attached cells remained bright blue when examined by 4',6-diamidine-2-phenylindole epifluo-rescence microscopy. The presence of added oxidized Mn had no effect on Fe reduction. The results suggested that enzymatic Fe reduction was responsible for reducing Fe in these cultures even in the presence of sulfide and that cells incapable of Fe reduction became unhealthy when Fe(III) was the only available electron acceptor.

An Arteriovenous Malformation of the External Ear in the Pediatric Population: A Case Report and Review of the Literature

The literature regarding arteriovenous malformations of the external ear is sparse. A case of a patient clinically diagnosed with an arteriovenous malformation of the external ear that was managed empirically with surgical excision, without recurrence, is presented. The pathogenesis, clinical presentation, radiological work up and management options regarding arteriovenous malformations are reviewed.

Decreasing Expander Breast Infection: A New Drain Care Protocol

BACKGROUND

Risk factors for expander reconstruction infection are well known. However, drain use as a risk factor for the development of infection is unclear.

OBJECTIVE

To review a simple method for drain use to help reduce rates of infection in expander breast reconstruction.

METHODS

Two hundred consecutive single-surgeon (JDM) immediate first-stage expander breast reconstructions were retrospectively reviewed. The records were reviewed for history and physical examination, intraoperative technique, perioperative management, adjuvant therapy, and outcome with respect to expander infection necessitating premature explantation within the first eight weeks. Infection was defined on clinical basis, with or without culture positivity. All expanders (Mentor, USA) were the same model (textured, port-integrated and biodimensional). Two consecutive series of reconstructions were then created. The first series included 177 reconstructions while the second series included 23 reconstructions. Unlike the first series, the second series introduced a protocol in which all reconstructions received mupirocin 2% cream to the drain sites and all drains were removed at the end of the first week. Additionally, in the second series, all expanders were secluded from direct in vivo contact with the closed suction drain either by the use of an intervening Alloderm sling (LifeCell Corporation, USA, 15 of 23 breasts) or by subdermally tunnelling the drain superficial to an adequate fatty subcutaneous layer (eight of 23 breasts).

RESULTS

Patients who developed infection in the first series and all patients in the second series shared statistically the same level of aggregate risk factors (P=0.531). The infection rate (5.65%, 10 infections in 177 breasts) in the first series was statistically greater than in the second series (0%, 0 in 23 breasts, P=0.001).

CONCLUSIONS

The present study found that percutaneous closed suction drains do serve as an increased risk for expander infection. However, early results indicate that in vivo protection of the expander with Alloderm or subdermal tunnelling, topical antibiotic ointment use and early drain removal may significantly reduce expander infection.

Decreasing expander breast infection: A new drain care protocol

BACKGROUND

Risk factors for expander reconstruction infection are well known. However, drain use as a risk factor for the development of infection is unclear.

OBJECTIVE

To review a simple method for drain use to help reduce rates of infection in expander breast reconstruction.

METHODS

Two hundred consecutive single-surgeon (JDM) immediate first-stage expander breast reconstructions were retrospectively reviewed. The records were reviewed for history and physical examination, intra-operative technique, perioperative management, adjuvant therapy, and outcome with respect to expander infection necessitating premature explantation within the first eight weeks. Infection was defined on clinical basis, with or without culture positivity. All expanders (Mentor, USA) were the same model (textured, port-integrated and biodimensional). Two consecutive series of reconstructions were then created. The first series included 177 reconstructions while the second series included 23 reconstructions. Unlike the first series, the second series introduced a protocol in which all reconstructions received mupirocin 2% cream to the drain sites and all drains were removed at the end of the first week. Additionally, in the second series, all expanders were secluded from direct in vivo contact with the closed suction drain either by the use of an intervening Alloderm sling (LifeCell Corporation, USA, 15 of 23 breasts) or by subdermally tunnelling the drain superficial to an adequate fatty subcutaneous layer (eight of 23 breasts).

RESULTS

Patients who developed infection in the first series and all patients in the second series shared statistically the same level of aggregate risk factors (P=0.531). The infection rate (5.65%, 10 infections in 177 breasts) in the first series was statistically greater than in the second series (0%, 0 in 23 breasts, P=0.001).

CONCLUSIONS

The present study found that percutaneous closed suction drains do serve as an increased risk for expander infection. However, early results indicate that in vivo protection of the expander with Alloderm or subdermal tunnelling, topical antibiotic ointment use and early drain removal may significantly reduce expander infection.

An arteriovenous malformation of the external ear in the pediatric population: A case report and review of the literature

The literature regarding arteriovenous malformations of the external ear is sparse. A case of a patient clinically diagnosed with an arteriovenous malformation of the external ear that was managed empirically with surgical excision, without recurrence, is presented. The pathogenesis, clinical presentation, radiological work up and management options regarding arteriovenous malformations are reviewed.

Quantifying cell-matrix adhesion dynamics in living cells using interference reflection microscopy

Focal adhesions and podosomes are integrin-mediated cell-substratum contacts that can be visualized using interference reflection microscopy (IRM). Here, we have developed automated image-processing procedures to quantify adhesion turnover from IRM images of live cells. Using time sequences of images, we produce adhesion maps that reveal the spatial changes of adhesions and contain additional information on the time sequence of these changes. Such maps were used to characterize focal adhesion dynamics in mouse embryo fibroblasts lacking one or both alleles of the vinculin gene. Loss of vinculin expression resulted in increased assembly, disassembly and/or in increased translocation of focal adhesions, suggesting that vinculin is important for stabilizing focal adhesions. This method is also useful for studying the rapid dynamics of podosomes as observed in primary mouse dendritic cells.

Management algorithm and outcome evaluation of partial mastectomy defects treated using reduction or mastopexy techniques

BACKGROUND

Reconstruction of the partial mastectomy defect has become increasingly popular because of poor cosmetic results in select patients. The purpose of this series was to try to create a treatment algorithm based on patient selection, diagnosis, margins, and recurrence in an attempt to maintain oncologic safety, as well as to improve esthetic outcome.

METHODS

A retrospective review of all patients treated at Emory University Hospital with partial mastectomy and reduction/mastopexy was performed. Reconstruction was performed either simultaneously or following confirmation of negative histologic margins.

RESULTS

Sixty-three women were included in the series. Histology was invasive carcinoma (n = 33), ductal carcinoma in situ (DCIS) (n = 20), fibroadenoma (n = 6), and benign breast tissue (n = 4). The Wise pattern was used 84% of the time (n = 53/63). The most common tumor location was upper outer quadrant, and the various pedicles used were superomedial (n = 22), inferior (n = 20), central (n = 7), and other (n = 14). Eight patients had reduction/mastopexy once final pathology confirmed negative margins. The average biopsy weight was 236 g. Total specimen weight on the tumor side was 762 g and 858 g on the contralateral side, to accommodate for radiation fibrosis. Immediate complications were seen in 22% of cases and included delayed healing (n = 9), infection (n = 1), partial nipple loss (n = 1), hematoma (n = 1), and skin necrosis (n = 1). In patients with breast cancer (n = 53), 26% required either fine needle aspiration or excisional biopsy for cancer surveillance postoperatively. Oncoplastic surgery was the definitive procedure 93% of the time. Completion mastectomy with reconstruction was required in 4 patients, 3 for positive margins extensive DCIS and 1 for residual microcalcifications (stereobiopsy DCIS) despite adequate specimen radiograph and negative margins initially. All 4 patients who failed the combined approach were younger women with the diagnosis of extensive DCIS. The locoregional recurrence rate was 2%, and all patients had no evidence of disease at an average follow-up of 3.25 years.

CONCLUSION

Therapeutic mammaplasty is a useful procedure for shape and symmetry preservation in women with large or ptotic breasts. Versatility exists using various pedicles and skin patterns to reconstruct all breast shapes and defect locations. Younger patients with extensive DCIS are poor candidates for simultaneous reconstruction, and should be deferred until confirmation of negative margins. If surgical management of residual disease requires completion mastectomy, immediate reconstruction is possible, with skin preservation and no adverse effects.

Mechanism of Phosphodiesterase 5 inhibitor relief of prostatitis symptoms

BACKGROUND

Chronic prostatitis is a common urological complaint without clearly defined causation or definitive treatment.

HYPOTHESIS

Phosphodiesterase 5 (PDE5) Inhibitor mediated relaxation of prostatic duct smooth muscle increases washout of prostatic reflux products reducing prostatic inflammation and consequent prostatitis symptoms. RATIONALE OF HYPOTHESIS: The presence of both Nitric Oxide Synthase and Phosphodiesterase 5 in human prostatic tissue and the effect of nitric oxide donors and PDE5 inhibitors in vitro indicate PDE5 inhibitors relax prostatic smooth muscle. Significant retrograde urinary flux into prostatic ducts has been described and suggested as the mechanism of chronic prostatitis. We postulate PDE5 inhibitors alter prostatic reflux hence prostatitis symptoms.

CONCLUSION

PDE5 inhibitors may represent a simple, effective treatment for chronic prostatitis.

Effect of wearing personal protective clothing and self-contained breathing apparatus on heart rate, temperature and oxygen consumption during stepping exercise and live fire training exercises

Fire fighter breathing apparatus instructors (BAIs) must possess the ability to respond to both the extrinsic stress of a high temperature environment and the intrinsic stress from wearing personal protective equipment (PPE) and self-contained breathing apparatus (SCBA), repeatedly and regularly, whilst training recruits in live fire training exercises (LFTEs). There are few previous investigations on BAIs in hot environments such as LFTEs, since the main research focus has been on regular fire fighters undertaking exercises in temperate or fire conditions at a moderate to high exercise intensity. In this study, the intrinsic cardiovascular stress effects of wearing PPE + SCBA were first investigated using a step test whilst wearing gym kit (control), weighted gym kit (a rucksack weighted to the equivalent of PPE + SCBA) and full PPE + SCBA (weight plus the effects of protective clothing). The extrinsic effects of the very hot environment were investigated in BIAs in LFTEs compared to mock fire training exercises (MFTEs), where the fire was not ignited. There was an increase in heart rate due to the modest workload imposed on the BAIs through carrying out the MFTEs (25.0 (18.7)%) compared to resting. However, when exposed to fire during the LFTEs, heat storage appears to be significant as the heart rate increased by up to 39.8 (+/-20.1)% over that of the mock LFTEs at temperate conditions. Thus, being able to dissipate heat from the PPE is particularly important in reducing the cardiovascular responses for BAIs during LFTEs.

Salvage of Infected Spinal Hardware With Paraspinous Muscle Flaps

PURPOSE

Infected spinal stabilization devices represent a significant reconstructive challenge by threatening spinal stability and increasing the risk of neurologic complications. This study provides an anatomic and clinical investigation of posterior midline trunk reconstruction using paraspinous muscle flaps as the primary method of repair.

METHODS

We retrospectively analyzed a series of 25 consecutive patients (mean age, 57.2 years; range, 32-78 years) with complex spinal wounds, reconstructed with paraspinous muscle flaps, at a single university healthcare system. To help define the versatility of these muscle flaps, we also performed cadaveric dissections with lead oxide injections in 10 specimens, with an emphasis on regional blood supply, flap width, and arc of rotation.

RESULTS

From 1994 to 2000, we successfully reconstructed 25 patients with complex spinal wounds, using 49 paraspinous muscle flaps as the primary method of reconstruction. Hardware present in 22 patients was replaced or retained in 17 cases. Long-term spinal fusion with preservation of neurologic status was observed in all patients, with no cases of dehiscence or reinfection. Wound complications included cerebrospinal fluid leak (1), skin necrosis (1), sinus tracts (3), and seroma (2). Mean length of stay was 24 days (range, 8-57 days). One postoperative death occurred. Paraspinous dissections and injections confirmed a segmental type IV blood supply with medial and lateral perforators, arising from intercostal vessels superiorly and lumbar and sacral vessels inferiorly. Flap width was 8 cm at the sacral base, 5 cm at the level of the inferior scapular angle, and 2.5 cm at the first thoracic vertebra.

CONCLUSIONS

Paraspinous muscle flaps can be used as the primary reconstructive option to cover and preserve spinal hardware, control local infection, and enable long-term spinal stabilization. Cadaveric dissections confirmed the usefulness of paraspinous flaps, which can be based upon lateral or medial perforators and can be safely mobilized to reliably reconstruct complex spinal wounds.

Pharmacological rescue of noise induced hearing loss using N-acetylcysteine and acetyl-L-carnitine

Despite the use of hearing protection devices (HPDs) and engineering changes designed to improve workspaces, noise-induced hearing loss continues to be one of the most common and expensive disabilities in the US military. Many service members suffer acoustic trauma due to improper use of HPDs, sound levels exceeding the protective capacity of the HPDs, or by unexpected, injurious exposures. In these cases, there is no definitive treatment for the hearing loss. This study investigated the use of the pharmacological agents N-acetylcysteine and acetyl-L-carnitine after acoustic trauma to treat cochlear injury. N-Acetylcysteine is an antioxidant and acetyl-L-carnitine a compound that maintains mitochondrial bio-energy and integrity. N-Acetylcysteine and acetyl-L-carnitine, respectively, significantly reduced permanent threshold shifts and hair cell loss compared to saline-treated animals when given 1 and 4 h post-noise exposure. It may be possible to obtain a greater therapeutic effect using these agents in combination or at higher doses or for a longer period of time to address the secondary oxidative events occurring 7-10 days after acute noise exposure.

The role of muscle flaps in wound salvage after vascular graft infections: the Emory experience

BACKGROUND

The incidence of prosthetic graft infection is 1 to 6 percent, and the mortality rate of infected aortoiliac or aortofemoral bypass is 25 to 75 percent. The goal of this study was to report the use of muscle flaps in the management of patients presenting with infected vascular grafts.

METHODS

A total of 22 patients required 26 muscle flaps to cover 24 infected vascular grafts. Muscle flaps were used for local wound control in all patients regardless of the fate of the graft. The vascular surgeons elected for graft salvage in eight of the 24 grafts. All of the muscle flaps survived.

RESULTS

The average time interval between the bypass and infection was 371 days. One-month follow-up revealed an 88 percent salvage rate, but this decreased to 50 percent during the mean follow-up of 23 months. None of the patients originally managed with a salvaged graft lost a limb, and overall, 14 of 22 limbs in this series remained viable (64.0 percent). The mortality rate during the index hospitalization was 9 percent. In this series, suprainguinal grafts had a higher mortality rate. In addition, infection occurring more than 1 month postoperatively, culture-positive Pseudomonas and methicillin-resistant species, and exposure of the arterial-graft anastomosis were poor prognostic indicators of graft preservation.

CONCLUSIONS

Management of infected vascular grafts remains a challenging problem. Muscle flap coverage should have a high priority, as the chance of a good outcome is highly favorable in early infections.

The effects of a high carbohydrate diet on cortisol and salivary immunoglobulin A (s-IgA) during a period of increase exercise workload amongst Olympic and Ironman triathletes

The present study observed the effects of a 6-day high carbohydrate (H-CHO) diet on salivary cortisol and IgA during a period of increased exercise workload. Thirty-two competitively trained male triathletes were randomly allocated into a self-selected (SS), or an H-CHO (12 g CHO kgbm (-1) . day (-1)) dietary group. In addition to their training regimes, all subjects performed a 1-hour running exercise bout at 70 % V.O (2max) . d (-1), for six days. Saliva samples were taken pre, immediately post, and morning post-exercise bout on days 1, 4, and 6. The concentrations of s-IgA and cortisol were determined by ELISA assays. There was a significant (p < 0.001) interaction between Group x Time for cortisol, with a marked increase in concentrations occurring in the SS dietary group pre to post exercise, and pre to morning post-exercise (p < 0.01). Conversely, a significant (p = 0.009) Group x Time interaction reflected higher post exercise s-IgA concentrations (p < 0.005) than pre exercise in the H-CHO diet group. Blood glucose concentration decreased pre to post exercise in the SS diet group (p < 0.01), whilst remaining stable in the H-CHO group. It is concluded that the consumption of a high CHO diet throughout a 6-day period of overtraining had a favourable effect on markers of immune activity and thereby reduced the susceptibility of these endurance athletes to upper respiratory tract infection URTI.

Rho family GTPases are activated during HGF-stimulated prostate cancer-cell scattering

An important process in embryogenesis and cancer-cell metastasis is the conversion of epithelial cells to a migratory phenotype, a phenomenon known as epithelial-mesenchymal transition (E-MT). To achieve E-MT, cells dissociate from neighbouring cells and adopt a migratory morphology. This transition requires remodelling of their cell shape and substratum adhesions; activities that require extensive reorganisation of the actin cytoskeleton. Hepatocyte growth factor (HGF)-induced scattering of Madin Darby canine kidney (MDCK) cells is a routinely used model of E-MT, in which actin cytoskeletal rearrangement is known to be dependent on Rho family GTPases. We have developed a novel model of HGF-induced E-MT using the human prostate cancer cell line, DU145. This model overcomes the limitation of using a canine cell line and facilitates the study of E-MT in human cancer. We demonstrate for the first time the scattering response of individual DU145 cells to HGF in real time and have characterised changes in actin cytoskeletal organisation and cell adhesions as these cells respond to HGF. HGF-induced scattering of DU145 cells is dependent on the activity of Rho family GTPases, and using this model, we are able to demonstrate for the first time that endogenous Cdc42 is activated downstream of HGF. Furthermore we have also shown that the response of DU145 cells to HGF is dependent on a phosphatidylinositide 3-kinase pathway.

Immediate endoscopic latissimus dorsi flap: risk or benefit in reconstructing partial mastectomy defects

Management of the partial mastectomy defect has become a common entity as a result of the improved popularity and equivalent survival associated with breast conservation therapy (BCT). Numerous reconstructive options have been proposed in select patients following BCT in an attempt to maintain esthetic results. Thirty-nine women underwent simultaneous endoscope-assisted latissimus muscle transfer at the time of resection and were included in this review. The average follow-up was 3.7 years. Patient demographics and tumor characteristics were discussed. Donor site morbidity was acceptable. Tumor recurrence was experienced in 6 patients (15%) following lumpectomy and latissimus reconstruction. Two patients had local recurrence, and 4 had distant recurrence. Thirty-three patients (85%) had no evidence of disease at long-term follow-up. Lumpectomy and latissimus flap transfer was the definitive reconstructive procedure in 33 of the 39 patients (85%). Patients who subsequently required completion mastectomy were easily reconstructed with a TRAM flap or implants. As the management of partial mastectomy defects continues to challenge the plastic surgeon, we are noticing a shift away from immediate simultaneous reconstructions based on arguments regarding the appropriateness from an oncological and reconstructive perspective. Stringent patient selection, confirmation of negative margins, and possibly delaying the latissimus flap transfer will maximize the benefits of this reconstructive modality while limiting the risk.

A reconstructive algorithm for plastic surgery following extensive chest wall resection

Chest wall reconstruction following extensive resection is greatly facilitated by the use of vascularised flaps and prosthetic material. Plastic surgeons are often asked to assist with coverage of large chest wall defects. However, in addition to soft tissue coverage, we need to address other important issues such as the status of the pleural cavity, and the requirement for skeletal support. The purpose of this report is to analyse our experience, provide a reconstructive algorithm following the ablative procedure and review the literature. Two hundred chest wall resections were performed from 1975 to 2000. Defect location was divided into anterior (n = 73) lateral (n = 36) anterior-lateral (n = 36) posterior-lateral (n = 19) posterior (n = 22) and forequarter (n = 14) Average number of ribs resected was four. One hundred and fifty-eight patients (79%) required chest wall reconstruction with either prosthetic material and/or flap closure. Mesh closure was required in 85 cases (43%), being highest for lateral defects (61%), and lowest for anterior defects (31%). Vascularised flaps were needed in 112 patients (56%), more common in anterior defects (79%), and less common for the posterior-lateral defects (26%). Inpatient complication rate was 27% (43/158) following reconstruction, with a mortality of 6% (10/158). Chest wall reconstruction is common following extensive resection. This includes management of the pleural cavity, skeletal support and soft tissue coverage. A better understanding of the respiratory mechanics and local thoracoabdominal anatomy is crucial for managing these complex defects. The need for skeletal support was more prevalent in lateral and posterior-lateral defects. Flap reconstruction was required more often to cover large anterior defects, with regional flaps predominating.

Factors That Influence the Completion of Breast Reconstruction

Post mastectomy breast reconstruction continues to evolve in both timing and technique; however, multiple surgical procedures are usually required. The purpose of this report was to determine the number of secondary procedures required to complete the breast reconstruction and factors that influence this process. All patients who underwent breast reconstruction at Emory University Hospital between 1975 and 2000 were reviewed. The end point and inclusion criterion was completion to nipple reconstruction. Secondary procedures were determined per patient for either unilateral or bilateral reconstructions, and defined as any surgical manipulation of the reconstructed breast, contralateral breast, or donor site. The cohort was stratified by timing and method of reconstruction. Additional variables included risk factors, radiation therapy, and complications. A total of 888 patients completed the reconstructive process (738 unilateral and 150 bilateral). The average number of secondary procedures was 3.99 for unilateral, and 5.54 for bilateral. Delayed reconstructions had a higher number of secondary procedures in both groups. Transverse rectus abdominus musculocutaneous flap reconstruction tended to have more secondary procedures than implant or latissimus dorsi with or without implant reconstructions. Radiation therapy increased the number of secondary procedures in unilateral (3.9 versus 4.6, P < 0.001) and in bilateral reconstructions (5.7 versus 6.4, P = 0.032). The number of secondary procedures also increased exponentially with the number of risk factors (0-4), and patients with any complication had a higher number of secondary procedures for unilateral (4.5 versus 3.6, P < 0.001) and bilateral reconstructions (6.4 versus 4.5, P < 0.001). Secondary breast and donor site procedures were used as an outcome measure to formulate comparisons. Autologous tissue reconstruction required more secondary procedures, likely in part to donor site revisions. Delayed reconstruction, the need for radiation therapy, any complication, and more risk factors significantly increased the number of secondary procedures required to complete the reconstructive process.

Opioid peptides and dipeptidyl peptidase in autism

It has been hypothesized that autism results from an 'opioid peptide excess'. The aims of this study were to (1) confirm the presence of opioid peptides in the urine of children with autism and (2) determine whether dipeptidyl peptidase IV (DPPIV/CD26) is defective in children with autism. Opioid peptides were not detected in either the urine of children with autism (10 children; nine males, one female; age range 2 years 6 months to 10 years 1 month) or their siblings (10 children; seven males, three females; age range 2 years 3 months to 12 years 7 months) using liquid chromatography-ultraviolet-mass spectrometric analysis (LC-UV-MS). Plasma from 11 normally developing adults (25 years 5 months to 55 years 5 months) was also tested. The amount and activity of DPPIV in the plasma were quantified by an ELISA and DPPIV enzyme assay respectively; DPPIV was not found to be defective. The percentage of mononuclear cells expressing DPPIV (as CD26) was determined by flow cytometry. Children with autism had a significantly lower percentage of cells expressing CD3 and CD26, suggesting that they had lower T-cell numbers than their siblings. In conclusion, this study failed to replicate the findings of others and questions the validity of the opioid peptide excess theory for the cause of autism.

Importance of right subcostal incisions in patients undergoing TRAM flap breast reconstruction

The presence of a preexisting subcostal incision alters the approach to breast reconstruction and is thought to predispose to donor site skin complications and flap loss. The purpose of this study was to determine whether the presence of a subcostal scar affects breast or donor site morbidity adversely after transverse rectus abdominis musculocutaneous (TRAM) flap breast reconstruction. Twenty-six patients with a right subcostal incision (group A) underwent TRAM flap breast reconstruction (13 immediate, 13 delayed). The average age was 51 years, and the patients had an average body mass index of 25.3. There were 15 right, 10 left, and 1 bilateral reconstruction (4 free flaps, 22 pedicled). Outcome measures were compared with 126 age- and risk-matched patients (group B) who underwent TRAM flap reconstruction without any preexisting abdominal scar. The average age in group B was 46.7 years, and the patients had an average body mass index of 24.8. The average length of stay in group A was 5.9 days, compared with 4.8 days in group B ( < 0.05). There were no significant differences in breast-related complications. Donor site complications were higher in group A, with abdominal wall skin necrosis being significantly higher in patients with a subcostal incision (25%) compared with those patients without abdominal wall scars (5%; = 0.02). Multivariate analysis revealed a 6.5-fold increase in donor site complications in patients with a subcostal incision and a smoking history ( < 0.05). When adjusted for radiation treatment, the increased incidence in donor site complication rate was only marginally significant ( = 0.08). TRAM flap breast reconstruction in patients with preexisting right subcostal scars is effective with certain technical modifications; however, there is a slight predisposition to increased abdominal wall complications. Smoking influenced outcome further in patients with a subcostal incision, stressing the importance of proper patient selection.

Trends in unilateral breast reconstruction and management of the contralateral breast: the Emory experience

Recent trends in breast reconstruction have transitioned toward the skin-sparing type of mastectomy and immediate reconstruction using autologous tissue. This study was designed to document trends in the management of patients with unilateral breast cancer and to determine how they influence management of the contralateral breast. All patients who underwent unilateral breast reconstruction at Emory University Hospitals from January of 1975 to December of 1999 were reviewed. The cohort was stratified by timing of reconstruction (immediate versus delayed), method of reconstruction, and mastectomy type (skin-sparing versus non-skin-sparing). The methods of reconstruction included implant, latissimus dorsi flap, and transverse rectus abdominis musculocutaneous (TRAM) flap. Contralateral procedures to achieve symmetry included augmentation, mastopexy, augmentation/mastopexy, and reduction. A total of 1394 patients were evaluated, including 689 delayed and 705 immediate reconstructions. Sixty-seven percent of delayed-reconstruction patients (462 of 689) had a symmetry procedure performed on the opposite breast, compared with 22 percent for the immediate-reconstruction patients (155 of 705) (p </= 0.001). The percentage of times a contralateral procedure was performed was highest for implant reconstructions (89 percent delayed and 57 percent immediate) and lowest for TRAM flap reconstructions (59 percent delayed and 18 percent immediate). Augmentation mammaplasty was the most common symmetry procedure for implant reconstruction (41 percent), whereas reduction was the most common procedure for autologous tissue reconstruction (57 percent). Immediate unilateral breast reconstructions were stratified into non-skin-sparing mastectomy (n = 205) and skin-sparing mastectomy (n = 500). Thirty-four percent of patients with a non-skin-sparing mastectomy defect (70 of 205) underwent a contralateral breast procedure, compared with 17 percent of patients with a skin-sparing mastectomy defect (85 of 500) (p = 0.001). The percentage of times a contralateral procedure was performed in immediate reconstruction, stratified by mastectomy and reconstruction type, was only significant for TRAM flap reconstructions (25 versus 11 percent). Trends in the management of unilateral breast cancer from delayed to immediate reconstruction and from implants to autologous tissue have reduced the incidence of contralateral symmetry procedures. Reduction mammaplasty is the most common symmetry procedure used for autologous tissue reconstruction, with augmentation predominating when implants are used. The type of mastectomy also effects the management of the opposite breast, with skin-sparing mastectomy further reducing the incidence of contralateral procedures in immediate TRAM flap reconstruction, compared with non-skin-sparing mastectomy.

Significance of intraabdominal compartment pressures following TRAM flap breast reconstruction and the correlation of results

Abdominal wall closure after transverse rectus abdominis myocutaneous (TRAM) flap breast reconstruction is often performed under considerable tension and may theoretically cause a component of abdominal compartment syndrome. This prospective study examined intraabdominal pressure after TRAM reconstruction and correlated the findings with clinical course and outcome. All patients who underwent pedicled TRAM flap breast reconstruction from November of 1999 to December of 2000 (n = 77) were included and compared with nonoperative controls (n = 24). Intraabdominal pressures were measured indirectly using the urinary catheter in the postanesthesia care unit on postoperative days 1 and 2. Outcome measures included vital signs, urinary output, net 24-degree fluid balance, and complications. The preoperative variables were age, body mass index, parity, and presence of an epidural. For statistical analysis, the TRAM patients were divided into three groups on the basis of type of closure (bipedicle, unipedicle, and mesh), which were compared by analysis of variance. A multivariate logistic regression was performed to identify risk factors for patients with intraabdominal pressures > or =20 mmHg who were thought to have a component of abdominal compartment syndrome. The incidence of complications was compared by chi-square, with statistical significance determined for p < 0.05. Average intraabdominal pressures were significantly higher in the bipedicled TRAM (14.1 mmHg) and unipedicle TRAM (9.9 mmHg) groups when compared with the mesh group (5 mmHg) and controls (3.7 mmHg; p < 0.001). Increased intraabdominal pressure was transient and peaked on postoperative day 1. Elevated pressure was associated with decreased urinary output, decreased net fluid balance, and increased respiratory rate. Patients with intraabdominal pressures > or =20 mmHg (n = 10) had a higher incidence of complications (60 percent) compared with patients who had pressures <20 mmHg (18 percent; p < 0.05). Elevated intraabdominal pressures were strongly associated with donor-site and general complications. Positive predictive factors for elevated pressure included body mass index and type of closure (bipedicled or bilateral). Multiple pregnancies seemed to have a protective effect.A transient component of abdominal compartment syndrome does exist after TRAM flap breast reconstruction. Bipedicle closure, nulliparous women, and increased body mass index were risk factors for elevated intraabdominal pressures. Tension-free mesh closure seemed to have a protective effect. Symptomatic trends and certain complications were associated with, and possibly explained by, an elevated intraabdominal pressure.

Chest wall resections and reconstruction: a 25-year experience

BACKGROUND

Chest wall defects continue to present a complicated treatment scenario for thoracic and reconstructive surgeons. The purpose of this study is to report our 25-year experience with chest wall resections and reconstructions.

METHODS

A retrospective review of 200 patients who had chest wall resections from 1975 to 2000 was performed.

RESULTS

Patient demographics included tobacco abuse, hypertension, diabetes mellitus, alcohol abuse, coronary artery disease, chronic obstructive pulmonary disease, and human immunodeficiency virus. Surgical indications included lung cancer, breast cancer, chest wall tumors, and severe pectus deformities. Twenty-nine patients had radiation necrosis and 31 patients had lung or chest wall infections. The mean number of ribs resected was 4 +/- 2 ribs. Fifty-six patients underwent sternal resections. In addition 14 patients underwent forequarter amputations. Immediate closure was performed in 195 patients whereas delayed closure was performed in 5 patients. Primary repair without the use of reconstructive techniques was possible in 43 patients. Synthetic chest wall reconstruction was performed using Prolene mesh, Marlex mesh, methyl methacrylate sandwich, Vicryl mesh, and polytetrafluoroethylene. Flaps utilized for soft tissue coverage were free flap (17 patients) and pedicled flap (96 patients). Mean postoperative length of stay was 14 +/- 14 days. Mean intensive care unit stay was 5 +/- 9 days. In-hospital and 30-day survival was 93%.

CONCLUSIONS

Chest wall resection with reconstruction utilizing synthetic mesh or local muscle flaps can be performed as a safe, effective one-stage surgical procedure for a variety of major chest wall defects.

Omental free flap reconstruction in complex head and neck deformities

BACKGROUND

Microvascular free flaps continue to revolutionize coverage options in head and neck reconstruction. This article reviews our 25-year experience with omental free tissue transfers.

METHODS

All patients who underwent free omental transfer to the head and neck region were reviewed.

RESULTS

Fifty-five patients were included with omental transfers to the scalp (25%), craniofacial (62%), and neck (13%) region. Indications were tumor resections, burn wound, hemifacial atrophy, trauma, and moyamoya disease. Average follow-up was 3.1 years (range, 2 months-13 years). Donor site morbidities included abdominal wound infection, gastric outlet obstruction, and postoperative bleeding. Recipient site morbidities included partial flap loss in four patients (7%) total flap loss in two patients (3.6%), and three hematomas.

CONCLUSIONS

The omental free flap has acceptable abdominal morbidity and provides sufficient soft tissue coverage with a 96.4% survival. The thickness \and versatility of omentum provide sufficient contour molding for craniofacial reconstruction. It is an attractive alternative for reconstruction of large scalp defects and badly irradiated tissue.

The muscle-specific marker desmin is expressed in a proportion of human dermal fibroblasts after their exposure to galectin-1

We have previously shown that galectin-1 is a factor capable of converting mouse dermal fibroblasts to the myogenic lineage [Cell Transplant 2000;9:519]. Here, we report that human dermal fibroblasts are also capable of expressing the myogenic marker, desmin, when grown in muscle-cell-conditioned media. Furthermore, the human foetal skin cells also express this marker when grown in the presence of galectin-1. These results highlight the importance of galectin-1 in the conversion of both human and murine skin cells to a myogenic lineage. Thus galectin-1 could be an important tool for use in autologous cell therapies for the treatment of human muscular dystrophies.

Coordination of cell polarization and migration by the Rho family GTPases requires Src tyrosine kinase activity

BACKGROUND

The ability of a cell to polarize and move is governed by remodeling of the cellular adhesion/cytoskeletal network that is in turn controlled by the Rho family of small GTPases. However, it is not known what signals lie downstream of Rac1 and Cdc42 during peripheral actin and adhesion remodeling that is required for directional migration.

RESULTS

We show here that individual members of the Rho family, RhoA, Rac1, and Cdc42, direct the specific intracellular targeting of c-Src tyrosine kinase to focal adhesions, lamellipodia, or filopodia, respectively, and that the adaptor function of c-Src (the combined SH3/SH2 domains coupled to green fluorescent protein) is sufficient for targeting. Furthermore, Src's catalytic activity is absolutely required at these peripheral cell-matrix attachment sites for remodeling that converts RhoA-dependent focal adhesions into smaller focal complexes along Rac1-induced lamellipodia (or Cdc42-induced filopodia). Consequently, cells in which kinase-deficient c-Src occupies peripheral adhesion sites exhibit impaired polarization toward migratory stimuli and reduced motility. Furthermore, phosphorylation of FAK, an Src adhesion substrate, is suppressed under these conditions.

CONCLUSIONS

Our findings demonstrate that individual Rho GTPases specify Src's exact peripheral localization and that Rac1- and Cdc42-induced adhesion remodeling and directed cell migration require Src activity at peripheral adhesion sites.

Configuration of human dendritic cell cytoskeleton by Rho GTPases, the WAS protein, and differentiation

The cellular mechanisms that configure the cytoskeleton during migration of dendritic cells (DCs) are poorly understood. Immature DCs assemble specialized adhesion structures known as podosomes at their leading edge; these are associated with the localized recruitment of the Wiskott-Aldrich Syndrome protein (WASp) and the actin organizing actin-related protein 2/3 complex. In immature DCs lacking WASp, podosomes are absent, residual dysmorphic lamellipodia and filopodia are nonpolarized, and migration is severely compromised. Microinjection studies indicate that podosome assembly and polarization require concerted action of Cdc42, Rac, and Rho, thereby providing a link between sequential protrusive and adhesive activity. Formation of podosomes is restricted to cells with an immature phenotype, indicating a specific role for these structures during the early migratory phase. (Blood. 2001;98:1142-1149)

Thoracic reconstruction with the omentum: indications, complications, and results

This study provides a retrospective analysis of 60 patients who underwent thoracic reconstruction with the omentum. Patients were identified by searching several databases to determine demographics, indications for surgery, operative technique, and postoperative course, including donor and recipient site morbidity. From January 1975 to May 2000, the authors harvested and transferred the omentum successfully (57 pedicled, 3 free) in 60 patients (mean age, 60 years; age range, 21-86 years) for sternal wound infections (N = 34), chest wall resections (N = 17), pectus deformities (N = 2), intrathoracic defects (N = 4), and breast reconstruction (N = 3). The omentum was used as a primary flap in 39 patients and as a salvage flap in 21 patients. Average operative time was 3.9 hours and average hospital stay was 34.3 days. Partial flap loss occurred in 7 patients, with no total flap failures. Morbidity included six abdominal wound infections and seven epigastric hernias. Mortality was 11.7%. The omentum can be harvested safely and used reliably to reconstruct varying thoracic wounds and defects. Specific indications from this series include osteoradionecrosis, chest wall tumors, massive sternal wounds, and refractory mediastinitis. Hultman CS, Culbertson JH, Jones GE, et al. Thoracic reconstruction with the omentum: indications, complications, and results.

The Wiskott-Aldrich syndrome: disordered actin dynamics in haematopoietic cells

The Wiskott-Aldrich syndrome protein (WASp) is a member of a unique family whose members share similar domain structures and are responsible for the transduction of signals from the cell membrane to the actin cytoskeleton. For WASp, the interactions with Rho family GTPases and the cytoskeletal organising complex Arp2/3 are critical to these functions, which when disturbed translate into abnormalities of haematopoietic cell signaling, polarisation, migration and phagocytosis. This review discusses the evidence for regulation of highly dynamic cytoskeletal structures by WASp and the consequences of disturbed function on some of these processes.

Cellular signaling in macrophage migration and chemotaxis

Whereas most cells in adult tissues are fixed in place by cell junctions, leukocytes are motile and able to migrate actively through the walls of blood vessels into surrounding tissues. The actin cytoskeleton of these cells plays a central role in locomotion, phagocytosis, and the regulation of cell shape that are crucial elements of neutrophil and monocyte/macrophage function. This review will concentrate on how macrophages in particular control the actin cytoskeleton to generate cell movement and the shape changes required for chemotaxis. It has recently become evident that a complex of seven proteins known as the Arp2/3 complex regulates the assembly of new actin filament networks at the leading front of moving cells. Proteins of the Wiskott-Aldrich Syndrome Protein (WASP) family bind directly to the Arp2/3 complex and stimulate its ability to promote the nucleation of new actin filaments. Upstream of the WASP family proteins, receptor tyrosine kinases, G-protein-coupled receptors, phosphoinositide-3-OH kinase (PI 3-kinase), and the Rho family of GTPases receive and transduce the signals that lead to actin nucleation through WASP-Arp2/3 action. Although many gaps remain in our understanding, we are now in a position to consider completing signaling pathways that are initiated from outside the cell to the actin rearrangements that drive cell motility and chemotaxis.

1-[2-[(Heteroaryloxy)heteroaryl]carbamoyl]indolines: novel and selective 5-HT2C receptor inverse agonists with potential as antidepressant/anxiolytic agents

Bisaryl ethers have been identified with excellent 5-HT2C affinity and selectivity over both 5-HT2A and 5-HT2B receptors. Compounds such as 11, 27 and 38 have potent oral activity in a centrally mediated pharmacodynamic model of 5-HT2C function and their potential as novel non-sedating anxiolytic and antidepressants is under investigation.

1-[2-[(Heteroarylmethoxy)aryl]carbamoyl]indolines are selective and orally active 5-HT2C receptor inverse agonists

Bisarylmethoxyethers have been identified with nanomolar 5-HT2C affinity and selectivity over both 5-HT2A and 5-HT2B receptors. Compounds such as 1, 2, 8, 12, 14 and 18 have potent oral activity in a centrally mediated pharmacodynamic model of 5-HT2C function and their therapeutic potential is currently under further investigation.

A factor implicated in the myogenic conversion of nonmuscle cells derived from the mouse dermis

Using the mdx mouse model for human Duchenne muscular dystrophy we have shown that a cell population residing in the dermis of C57B1/10ScSn mouse skin is capable of converting to a myogenic lineage when implanted into the mdx muscle environment. It was important to determine the characteristics of the converting cell. A previous in vitro study indicated that 10% of cells underwent conversion but only when the cells were grown in medium previously harvested from a myogenic culture. In the present study we cloned cells derived from the dermis to identify the converting cells. Clones grown in normal growth medium showed no conversion, but when grown in medium conditioned by muscle cells around 40% conversion was achieved in several individual clones. We investigated whether the protein beta-galactoside binding protein (betaGBP), which is secreted by myoblasts and acts as a cell growth regulator of fibroblasts. could be a candidate factor responsible for conversion. Medium harvested from COS-1 cells infected with a construct containing betaGBP has been used for this investigation. Growth of dermal fibroblasts in medium enriched with this factor showed a high rate of conversion to cells expressing muscle-specific factors.

Biarylcarbamoylindolines are novel and selective 5-HT(2C) receptor inverse agonists: identification of 5-methyl-1-[[2-[(2-methyl-3-pyridyl)oxy]- 5-pyridyl]carbamoyl]-6-trifluoromethylindoline (SB-243213) as a potential antidepressant/anxiolytic agent

The evolution, synthesis, and biological activity of a novel series of 5-HT(2C) receptor inverse agonists are reported. Biarylcarbamoylindolines have been identified with excellent 5-HT(2C) affinity and selectivity over 5-HT(2A) receptors. In addition, (pyridyloxypyridyl)carbamoylindolines have been discovered with additional selectivity over the closely related 5-HT(2B) receptor. Compounds from this series are inverse agonists at the human cloned 5-HT(2C) receptor, completely abolishing basal activity in a functional assay. The new series have reduced P450 inhibitory liability compared to a previously described series of 1-(3-pyridylcarbamoyl)indolines (Bromidge et al. J. Med. Chem. 1998, 41, 1598) from which they evolved. Compounds from this series showed excellent oral activity in a rat mCPP hypolocomotion model and in animal models of anxiety. On the basis of their favorable biological profile, 32 (SB-228357) and 40 (SB-243213) have been selected for further evaluation to determine their therapeutic potential for the treatment of CNS disorders such as depression and anxiety.

Frequency-dependent effects of glutamate antagonists on the vestibulo-ocular reflex of the cat

In the central nervous system, sensory and motor signals at different frequencies are transmitted most effectively by neural elements that have different dynamic characteristics. Dynamic differences may be due, in part, to the dynamics of neurotransmitter receptors. For example, N-methyl-D-aspartate (NMDA) receptors are thought to be a component of the "neural integrator" of the vestibulo-ocular reflex (VOR), which generates a signal proportional to eye position. We measured the effects of blockade of NMDA and AMPA/kainate receptors on the gain and phase of the VOR at frequencies between 0.1 and 8 Hz in alert cats. The competitive NMDA antagonist, APV, and the non-competitive antagonists, MK-801 and ketamine, all caused a pronounced reduction in VOR gain. Gain was more strongly attenuated at low frequencies (0.1-1 Hz) than at higher frequencies (2-8 Hz). The phase lead of the eye with respect to the head was increased up to 30 degrees. In contrast, the reduction in gain associated with drowsiness or surgical anesthesia was not frequency-dependent. Blockade of AMPA/kainate receptors by the competitive antagonists, CNQX and NBQX, reduced the gain of the VOR at all frequencies tested. We evaluated our results using a control systems model. Our data are consistent with participation of NMDA receptors in neural integration, but suggest that NMDA receptors also participate in transmission by other components of the VOR pathway, and that neural integration also employs other receptors. One possibility is that between 0.1 and 10 Hz, higher-frequency signals are transmitted primarily by AMPA/kainate receptors, and lower frequencies by NMDA receptors. This arrangement would provide a biological substrate for selective motor learning within a small frequency range.

Model studies on a synthetically facile series of N-substituted phenyl-N'-pyridin-3-yl ureas leading to 1-(3-pyridylcarbamoyl) indolines that are potent and selective 5-HT(2C/2B) receptor antagonists

A model series of 5-HT2C antagonists have been prepared by rapid parallel synthesis. These N-substituted phenyl-N'-pyridin-3-yl ureas were found to have a range of 5-HT2C receptor affinities and selectivities over the closely related 5-HT2A receptor. Extrapolation of simple SAR, derived from this set of compounds, to the more active but synthetically more complex 1-(3-pyridylcarbamoyl)indoline series allowed us to target optimal substitution patterns and identify potent and selective 5-HT(2C/2B) antagonists.

Effects of the presentation of false heart-rate feedback on the performance of two common heartbeat-detection tasks

Research has indicated that performance on heartbeat counting tasks may be influenced by beliefs about heart rate. Sixty male subjects were administered the Schandry heartbeat counting task after viewing fast, slow, or no heart rate feedback. Subjects were also administered the Whitehead signal-detection type task. Results indicated that subjects who received fast or no heartbeat feedback performed better on the Schandry task than subjects who received slow feedback. Feedback presentation did not affect performance on the Whitehead task. These results suggest that the Schandry task is influenced by external variables (expectations, beliefs) beyond pure awareness of "discrete" visceral sensations and, thus, may not be as powerful a method for determining awareness of individual heartbeats as some other paradigms.