The β-catenin C terminus links Wnt and sphingosine-1-phosphate signaling pathways to promote vascular remodeling and atherosclerosis

Canonical Wnt and sphingosine-1-phosphate (S1P) signaling pathways are highly conserved systems that contribute to normal vertebrate development, with key consequences for immune, nervous, and cardiovascular system function; despite these functional overlaps, little is known about Wnt/β-catenin-S1P cross-talk. In the vascular system, both Wnt/β-catenin and S1P signals affect vessel maturation, stability, and barrier function, but information regarding their potential coordination is scant. We report an instance of functional interaction between the two pathways, including evidence that S1P receptor 1 (S1PR1) is a transcriptional target of β-catenin. By studying vascular smooth muscle cells and arterial injury response, we find a specific requirement for the β-catenin carboxyl terminus, which acts to induce S1PR1, and show that this interaction is essential for vascular remodeling. We also report that pharmacological inhibition of the β-catenin carboxyl terminus reduces S1PR1 expression, neointima formation, and atherosclerosis. These findings provide mechanistic understanding of how Wnt/β-catenin and S1P systems collaborate during vascular remodeling and inform strategies for therapeutic manipulation.

Increased adipose catecholamine levels and protection from obesity with loss of Allograft Inflammatory Factor-1

Recent studies implicate macrophages in regulation of thermogenic, sympathetic neuron-mediated norepinephrine (NE) signaling in adipose tissues, but understanding of such non-classical macrophage activities is incomplete. Here we show that male mice lacking the allograft inflammatory factor-1 (AIF1) protein resist high fat diet (HFD)-induced obesity and hyperglycemia. We link this phenotype to higher adipose NE levels that stem from decreased monoamine oxidase A (MAOA) expression and NE clearance by AIF1-deficient macrophages, and find through reciprocal bone marrow transplantation that donor Aif1-/- vs WT genotype confers the obesity phenotype in mice. Interestingly, human sequence variants near the AIF1 locus associate with obesity and diabetes; in adipose samples from participants with obesity, we observe direct correlation of AIF1 and MAOA transcript levels. These findings identify AIF1 as a regulator of MAOA expression in macrophages and catecholamine activity in adipose tissues - limiting energy expenditure and promoting energy storage - and suggest how it might contribute to human obesity.

Allograft inflammatory factor-1-like is a situational regulator of leptin levels, hyperphagia, and obesity

Mouse models enable the study of genetic factors affecting the complex pathophysiology of metabolic disorders. Here, we identify reductions in leptin levels, food intake, and obesity due to high-fat diet, accompanied by increased leptin sensitivity, in mice that harbor the E2a-Cre transgene within Obrq2, an obesity quantitative trait locus (QTL) that includes the leptin gene. Interestingly, loss of allograft inflammatory factor-1-like (AIF1L) protein in these transgenic mice leads to similar leptin sensitivity, yet marked reversal of the obesity phenotype, with accelerated weight gain and increased food intake. Transgenic mice lacking AIF1L also have low circulating leptin, which suggests that benefits of enhanced leptin sensitivity are lost with further impairment of leptin expression due to loss of AIF1L. Together, our results identify AIF1L as a genetic modifier of Obrq2 and leptin that affects leptin levels, food intake, and obesity during the metabolic stress imposed by HFD.

PLX3397, a CSF1 receptor inhibitor, limits allotransplantation-induced vascular remodelling

AIMS

Graft vascular disease (GVD), a clinically important and highly complex vascular occlusive disease, arises from the interplay of multiple cellular and molecular pathways. While occlusive intimal lesions are composed predominantly of smooth-muscle-like cells (SMLCs), the origin of these cells and the stimuli leading to their accumulation in GVD are uncertain. Macrophages have recently been identified as both potential drivers of intimal hyperplasia and precursors that undergo transdifferentiation to become SMLCs in non-transplant settings. Colony-stimulating factor-1 (CSF1) is a well-known regulator of macrophage development and differentiation, and prior preclinical studies have shown that lack of CSF1 limits GVD. We sought to identify the origins of SMLCs and of cells expressing the CSF1 receptor (CSF1R) in GVD, and to test the hypothesis that pharmacologic inhibition of CSF1 signalling would curtail both macrophage and SMLC activities and decrease vascular occlusion.

METHODS AND RESULTS

We used genetically modified mice and a vascular transplant model with minor antigen mismatch to assess cell origins. We found that neointimal SMLCs derive from both donor and recipient, and that transdifferentiation of macrophages to SMLC phenotype is minimal in this model. Cells expressing CSF1R in grafts were identified as recipient-derived myeloid cells of Cx3cr1 lineage, and these cells rarely expressed smooth muscle marker proteins. Blockade of CSF1R activity using the tyrosine kinase inhibitor PLX3397 limited the expression of genes associated with innate immunity and decreased levels of circulating monocytes and intimal macrophages. Importantly, PLX3397 attenuated the development of GVD in arterial allografts.

CONCLUSION

These studies provide proof of concept for pharmacologic inhibition of the CSF1/CSF1R signalling pathway as a therapeutic strategy in GVD. Further preclinical testing of this pathway in GVD is warranted.

Allograft inflammatory factor-1-like is not essential for age dependent weight gain or HFD-induced obesity and glucose insensitivity

The allograft inflammatory factor (AIF) gene family consists of two identified paralogs – AIF1 and AIF1-like (AIF1L). The encoded proteins, AIF1 and AIF1L, are 80% similar in sequence and show conserved tertiary structure. While studies in human populations suggest links between AIF1 and metabolic diseases such as obesity and diabetes, such associations with AIF1L have not been reported. Drawing parallels based on structural similarity, we postulated that AIF1L might contribute to metabolic disorders, and studied it using mouse models. Here we report that AIF1L is expressed in major adipose depots and kidney but was not detectable in liver or skeletal muscle; in notable contrast to AIF1, AIF1L was also not found in spleen. Studies of AIF1L deficient mice showed no obvious postnatal developmental phenotype. In response to high fat diet (HFD) feeding for 6 or 18 weeks, WT and AIF1L deficient mice gained weight similarly, showed no differences in fat or lean mass accumulation, and displayed no changes in energy expenditure or systemic glucose handling. These findings indicate that AIF1L is not essential for the development of obesity or impaired glucose handling due to HFD, and advance understanding of this little-studied gene and its place in the AIF gene family.

Allograft inflammatory factor-1 supports macrophage survival and efferocytosis and limits necrosis in atherosclerotic plaques

BACKGROUND AND AIMS

Allograft inflammatory factor-1 (AIF1) has been characterized as a pro-inflammatory molecule expressed primarily in the monocyte/macrophage (MP) lineage and positively associated with various forms of vascular disease, including atherosclerosis. Studies of AIF1 in atherosclerosis have relied on mouse models in which AIF1 was overexpressed in either myeloid or smooth muscle cells, resulting in increased atherosclerotic plaque burden. How physiologic expression of AIF1 contributes to MP biology in atherogenesis is not known.

METHODS

Effects of global AIF1 deficiency on atherosclerosis were assessed by crossing Aif1^-/- and ApoE^-/- mice, and provoking hyperlipidemia with high fat diet feeding. Atherosclerotic plaques were studied en face and in cross section. Bone marrow-derived MPs (BMDMs) were isolated from Aif1^-/- mice for study in culture.

RESULTS

Atherosclerotic plaques in Aif1^-/-;ApoE^-/- mice showed larger necrotic cores compared to those in ApoE^-/- animals, without change in overall lesion burden. In vitro, lack of AIF1 reduced BMDM survival, phagocytosis, and efferocytosis. Mechanistically, AIF1 supported activation of the NF-κB pathway and expression of related target genes involved in stress response, inflammation, and apoptosis. Consistent with this in vitro BMDM phenotype, AIF1 deficiency reduced NF-κB pathway activity in vivo and increased apoptotic cell number in atherosclerotic lesions from Aif1^-/-;ApoE^-/- mice.

CONCLUSIONS

These findings characterize AIF1 as a positive regulator of the NF-κB pathway that supports MP functions such as survival and efferocytosis. In inflammatory settings such as atherosclerosis, these AIF1-dependent activities serve to clear cellular and other debris and limit necrotic core expansion, and may oppose lesion destabilization.

Inhibition of Smooth Muscle β-Catenin Hinders Neointima Formation After Vascular Injury

OBJECTIVE

Smooth muscle cells (SMCs) contribute to neointima formation after vascular injury. Although β-catenin expression is induced after injury, whether its function is essential in SMCs for neointimal growth is unknown. Moreover, although inhibitors of β-catenin have been developed, their effects on SMC growth have not been tested. We assessed the requirement for SMC β-catenin in short-term vascular homeostasis and in response to arterial injury and investigated the effects of β-catenin inhibitors on vascular SMC growth.

APPROACH AND RESULTS

We used an inducible, conditional genetic deletion of β-catenin in SMCs of adult mice. Uninjured arteries from adult mice lacking SMC β-catenin were indistinguishable from controls in terms of structure and SMC marker gene expression. After carotid artery ligation, however, vessels from mice lacking SMC β-catenin developed smaller neointimas, with lower neointimal cell proliferation and increased apoptosis. SMCs lacking β-catenin showed decreased mRNA expression of Mmp2, Mmp9, Sphk1, and S1pr1 (genes that promote neointima formation), higher levels of Jag1 and Gja1 (genes that inhibit neointima formation), decreased Mmp2 protein expression and secretion, and reduced cell invasion in vitro. Moreover, β-catenin inhibitors PKF118-310 and ICG-001 limited growth of mouse and human vascular SMCs in a dose-dependent manner.

CONCLUSIONS

SMC β-catenin is dispensable for maintenance of the structure and state of differentiation of uninjured adult arteries, but is required for neointima formation after vascular injury. Pharmacological β-catenin inhibitors hinder growth of human vascular SMCs. Thus, inhibiting β-catenin has potential as a therapy to limit SMC accumulation and vascular obstruction.

Insulin induces IRS2-dependent and GRK2-mediated β2AR internalization to attenuate βAR signaling in cardiomyocytes

The counter-regulatory effects of insulin and catecholamines on carbohydrate and lipid metabolism are well studied, whereas the details of insulin regulation of β adrenergic receptor (βAR) signaling pathway in heart remain unknown. Here, we characterize a novel signaling pathway of insulin receptor (IR) to G protein-coupled receptor kinase 2 (GRK2) in the heart. Insulin stimulates recruitment of GRK2 to β2AR, which induces β2AR phosphorylation at the GRK sites of serine 355/356 and subsequently β2AR internalization. Insulin thereby suppresses βAR-induced cAMP-PKA activities and contractile response in neonatal and adult mouse cardiomyocytes. Deletion of insulin receptor substrate 2 (IRS2) disrupts the complex of IR and GRK2, which attenuates insulin-mediated β2AR phosphorylation at the GRK sites and β2AR internalization, and the counter-regulation effects of insulin on βAR signaling. These data indicate the requirements of IRS2 and GRK2 for insulin to stimulate counter-regulation of βAR via β2AR phosphorylation and internalization in cardiomyocytes.

Insulin inhibits cardiac contractility by inducing a Gi-biased β2-adrenergic signaling in hearts

Insulin and adrenergic stimulation are two divergent regulatory systems that may interact under certain pathophysiological circumstances. Here, we characterized a complex consisting of insulin receptor (IR) and β2-adrenergic receptor (β2AR) in the heart. The IR/β2AR complex undergoes dynamic dissociation under diverse conditions such as Langendorff perfusions of hearts with insulin or after euglycemic-hyperinsulinemic clamps in vivo. Activation of IR with insulin induces protein kinase A (PKA) and G-protein receptor kinase 2 (GRK2) phosphorylation of the β2AR, which promotes β2AR coupling to the inhibitory G-protein, Gi. The insulin-induced phosphorylation of β2AR is dependent on IRS1 and IRS2. After insulin pretreatment, the activated β2AR-Gi signaling effectively attenuates cAMP/PKA activity after β-adrenergic stimulation in cardiomyocytes and consequently inhibits PKA phosphorylation of phospholamban and contractile responses in myocytes in vitro and in Langendorff perfused hearts. These data indicate that increased IR signaling, as occurs in hyperinsulinemic states, may directly impair βAR-regulated cardiac contractility. This β2AR-dependent IR and βAR signaling cross-talk offers a molecular basis for the broad interaction between these signaling cascades in the heart and other tissues or organs that may contribute to the pathophysiology of metabolic and cardiovascular dysfunction in insulin-resistant states.

The effectiveness of a musical toothbrush for dental plaque removal: a comparative study

BACKGROUND AND OBJECTIVES

the purpose of this study was to clinically evaluate and compare the efficacy of "Brush Buddies" musical tooth brush and Colgate Smile tooth brush in the reduction of established plaque and gingivitis.

MATERIALS AND METHODS

for this study, 120 healthy kids (73 boys and 47 Girls) were selected. The subjects were randomly assigned into two groups by a second examiner; one group used Colgate Smile brush and the other group used "Brush Buddies" musical tooth brush. Plaque index (Quigley and Hein), Modified Gingival Index (Lobene and Associates) and Gingival Bleeding Index (Ainamo and Bay) were assessed at baseline, 30th day, 60th day, and 90th day.

RESULTS

all the baseline indices appeared to be well balanced. At the end of the study, reduction in plaque index, modified gingival index and gingival bleeding index were statistically highly significant during each interval for both the toothbrushes. For "Brush Buddies" musical tooth brush, the reduction in all clinical parameters were statistically significant for 30 days and 60 days interval, while nonsignificant at 90 days interval.

INTERPRETATION AND CONCLUSION

both the tooth brushes used in this study were clinically effective in removing plaque, improving gingival health. Musical tooth brush is more effective initially but as the time period increases both tooth brushes give almost similar results.

Warfarin therapeutic monitoring: is 70% time in the therapeutic range the best we can do?

WHAT IS KNOWN AND OBJECTIVE

Warfarin, an oral anticoagulant, which has been in clinical use for over sixty years, remains a challenge for clinicians to utilize, given the multiplicity of items which can limit its efficacy. Our objective is to review the evidence and comment on whether INR control can be better than has been currently reported in various studies.

COMMENT

The duration of time a patient's international normalized ratio (INR) is maintained within the therapeutic range (time in the therapeutic range, TTR) for his or her particular indication for the drug impacts the effectiveness and safety of warfarin therapy. Maintaining a therapeutic INR while on warfarin is difficult, and numerous studies employing various strategies confirm the challenge, but not the impossibility of achieving a TTR above 70%.

WHAT IS NEW AND CONCLUSION

Maintaining a therapeutic INR requires a dedicated multi-faceted approach. With diligence, skill and various therapeutic strategies, a TTR >70% can be achieved.

Is the routine placement of a CSF reservoir following endoscopic third ventriculostomy justified?

Endoscopic third ventriculostomy (ETV) is a well established treatment for selected cases of obstructive hydrocephalus. However, it does carry a significant rate of failure, which can be abrupt and life threatening. The present study analyses the benefits versus the risks of routine CSF reservoir insertion during ETV. Clinical data obtained from the medical records of patients from a single neurosurgical centre who underwent ETV between August 2002 and February 2007 were analysed retrospectively. A total of 34 records were available with follow-up ranging from 3-56 months (Median 26 months) and with patient age range between 6 months - 75 yrs (median 19 years). During this period, one neurosurgeon routinely placed reservoirs in all patients undergoing ETV (n = 34). In all instances of reservoir insertion, Ommaya reservoirs were used. The number of patients in which the reservoir was tapped for diagnostic and/or therapeutic reasons was quantified, and all complications resulting from reservoir placement recorded. ETV success was defined by a lack of subsequent need for cerebrospinal fluid diversion. In total 13 of 34 (38%) reservoirs inserted were tapped at a later date and there were no complications associated with their insertion. Tapping of reservoirs helped determine which patients required subsequent ventriculoperitoneal (VP) shunting. In at least one case reservoir tapping was carried out as an emergency and was a crucial intermediate intervention prior to further surgery. The overall success rate of ETV was 65% (95% CI, 49-81%) with four complications associated with ETV: short-term memory loss, psychosis, and two cases of post-operative seizures. These complications were not attributed to CSF reservoir insertion but the ETV procedure itself. The routine placement of CSF reservoir following ETV thus seems justified with respect to the observed benefits and lack of complications associated with its placement.

Oesophageal replacement in children

INTRODUCTION

The usual indications for oesophageal replacement in childhood are intractable corrosive strictures and long-gap oesophageal atresia. Generally, paediatric surgeons attempt to preserve the native oesophagus with repeat dilatations. However, when this is not successful, an appropriate conduit must be fashioned to replace the oesophagus. The neo-oesophagus should allow normal oral feeding, not have gastro-oesophageal reflux, and be able to function well for the life-time of the patient.

PATIENTS AND METHODS

A Medline search for oesophageal replacement, oesophageal atresia, gastric transposition, colon transposition, gastric tube, caustic stricture was conducted. The commonest conduits including whole stomach, gastric tube, colon and jejunum are all discussed.

RESULTS

No randomised controlled studies exist comparing the different types of conduits available for children. The techniques used tend to be based on personal preference and local experience rather than on any discernible objective data. The biggest series with long-term outcome are reported for gastric transposition and colon replacement. Comparison of a number of studies shows no significant difference in early or late complications. Early operative complications include graft necrosis, anastomotic leaks and sepsis. Late problems include strictures, poor feeding, gastro-oesophageal reflux, tortuosity of the graft and the development of Barrett's oesophagus. The biggest series, however, seem to have lower complications than small series probably reflecting the experience, built up over years, in their respective centres.

CONCLUSIONS

Long-term follow-up is recommended because of the risks of late strictures, excessive tortuosity of the neo-oesophagus and the development of Barrett's oesophagus.

Endobronchial obstruction from an intubation stylet sheath

Many clinicians intubate newborns using a stylet, but how many always check if the device is intact after use? We describe a case of endobronchial obstruction by a plastic sheath coating the metal stylet, and suggest ways to reduce the incidence of this serious iatrogenic complication.

Emergency transjugular intrahepatic portosystemic shunt for uncontrolled variceal bleeding

This study was designed to retrospectively evaluate transjugular intrahepatic portosystemic shunt (TIPS) performed on an emergency basis in patients with hemorrhagic shock from recurrent uncontrolled variceal bleeding. Over a 3.5-year period we reviewed the medical records as well as the imaging studies of 16 patients who had uncontrolled variceal bleeding and presented to our department for an emergent placement of TIPS. In our study the technical success was 88% (14/16 patients), the overall mortality was 36% (5/14 patients), and the shunt immediately reduced the portal venous pressure gradient by a mean of 64%. Given the poor outcome of other alternatives, aggressive treatment and placement of TIPS is justified regardless of the severity of the bleeding episode.

Persistent rectal prolapse in children: sclerotherapy and surgical management

Persistent rectal prolapse is an uncommon but distressing condition in children. Significant controversy exists regarding its surgical management. The aim of this study was to identify a successful management strategy for persistent rectal prolapse in the paediatric population. Records of all children with rectal prolapse treated surgically at Birmingham Children's Hospital between 1995 and 2003 were retrospectively reviewed. Demographic data, clinical presentation, investigations, treatment modality, complications, and outcome were recorded. Inclusion criteria for the study were failure of conservative management leading to operative treatment. An exclusion criterion was cystic fibrosis. A total of 24 patients with persistent rectal prolapse were identified. Two children with cystic fibrosis were excluded from the analysis. Children below the age of 5 years, group I (n=17), were successfully managed by submucous hypertonic saline injections. Eighty-three percent (14/17) were cured by injection sclerotherapy in this group, 12/14 (71%) requiring one injection and 2/14 requiring a second injection. In the three (17.6%) children in group I in whom sclerotherapy failed, cow's milk protein (CMP) allergy was identified as the causative factor. Children older than 5, group II (n=5), either had behavioural problems (n=3) or were autistic (n=2). This group of children with adult-type, full-thickness rectal prolapse were found to be refractory to initial attempts of injection sclerotherapy. All five children were successfully managed with surgical correction. We conclude that rectal submucous hypertonic saline injections are highly effective for managing early-onset idiopathic childhood rectal prolapse. CMP allergy should be considered in young children with recurrent rectal prolapse. We recommend early definitive corrective surgery in older children with persistent rectal prolapse, as they do not respond to conservative measures or injection sclerotherapy.

Pulmonary metastasectomy for pediatric solid tumors

Most pediatric thoracic malignancy is pulmonary disease secondary to solid tumors of childhood. The management of isolated pulmonary metastases in adulthood is well documented. Little has been published to document the long-term outcome of pulmonary metastasectomy in childhood. A retrospective study was undertaken to assess the results of surgery for isolated pulmonary metastases. Twenty children underwent surgery over 12 years (mean follow-up 8 years). Five had Wilms' tumor (mean age 51 months), eight had osteogenic sarcoma (mean age 141 months), three had rhabdomyosarcoma (mean age 92 months), two had hepatoblastoma (mean age 30 months) and two had teratoma (mean age 72 months). Four had bilateral synchronous metastases and thoracotomies, and one had bilateral metachronous metastases and thoracotomies. Nineteen children were discharged well within 10 days of surgery. There was one early complication: a death due to pneumonia. Four children subsequently died postoperatively with cranial metastases (mean 29 months postoperatively). The remaining 16 children remain alive and well. As part of the combined therapy, these results would support an aggressive surgical approach to this disease. Preoperative assessment should include contrast enhanced computed tomogram of the head and chest as well as chest X-ray taken immediately preoperatively to exclude metastases. Bilateral synchronous and metachronous thoracotomy is well tolerated in childhood.

Axillary lipoblastoma--tumor recurrence in the right atrium

This case report describes, for the first time, vascular invasion and recurrence of a lipoblastoma 6 months after the macroscopically complete excision of the initial cervico-axillary tumour. The importance of cytogenetics in the diagnosis of lipoblastoma is emphasized, as is the need to be wary of the diagnosis of lipoma in infancy.

[Oral and extraoral disease due to betel nut chewing]

BACKGROUND AND OBJECTIVE

Betel chewing is common in India and southeast Asia. It shows mild psychostimulatory effects but with prolonged use there is a risk of oral and extraoral disease. Surprisingly, betel nut associated disorders are rarely discussed in the dermatological literature.

METHODS

A review about betel nut associated disease is given based on a literature review and our own experiences.

RESULTS

Both benign and malignant diseases can be induced by betel nut chewing. Betel causes reddish discoloration of teeth, periodontitis and buccal mucositis. Submucous fibrosis is a precancerous disease that may eventually develop into oral squamous cell cancer (OSCC). Among malignant diseases induced by betel quid, OSCC is the most important but esophageal cancer and hepatocellular cancer can also be observed. The available treatments are of limited value.

CONCLUSIONS

Betel nut chewing has its own morbidity and mortality due to the induction of benign and malignant diseases. There is a lack of controlled trials although both betel nut chewing and the associated diseases are common.

Where value lives in a networked world

While many management thinkers proclaim an era of radical uncertainty, authors Sawhney and Parikh assert that the seemingly endless upheavals of the digital age are more predictable than that: today's changes have a common root, and that root lies in the nature of intelligence in networks. Understanding the patterns of intelligence migration can help companies decipher and plan for the inevitable disruptions in today's business environment. Two patterns in network intelligence are reshaping industries and organizations. First, intelligence is decoupling--that is, modern high-speed networks are pushing back-end intelligence and front-end intelligence toward opposite ends of the network, making the ends the two major sources of potential profits. Second, intelligence is becoming more fluid and modular. Small units of intelligence now float freely like molecules in the ether, coalescing into temporary bundles whenever and wherever necessary to solve problems. The authors present four strategies that companies can use to profit from these patterns: arbitrage allows companies to move intelligence to new regions or countries where the cost of maintaining intelligence is lower; aggregation combines formerly isolated pieces of infrastructure intelligence into a large pool of shared infrastructure provided over a network; rewiring allows companies to connect islands of intelligence by creating common information backbones; and reassembly allows businesses to reorganize pieces of intelligence into coherent, personalized packages for customers. By being aware of patterns in network intelligence and by acting rather than reacting, companies can turn chaos into opportunity, say the authors.

p53 inactivation in chewing tobacco-induced oral cancers and leukoplakias from India

The inactivation of p53 tumour suppressor gene vis-á-vis point mutation, overexpression and degradation due to Human Papilloma virus (HPV) 16/18 infection, was examined in chewing tobacco-associated oral cancers and oral leukoplakias from India. The analysis of mutations was assessed by polymerase chain reaction (PCR) with single strand conformation polymorphism (PCR-SSCP) of exons 5-9 on DNA from 83 oral cancer cases, and the mutations confirmed by direct nucleotide sequencing of the PCR products. p53 protein expression was evaluated by immunohistochemical analysis on paraffin-embedded sections of 62 representative oral cancer biopsies and 22 leukoplakias, using p53-specific monoclonal antibody DO-7. The presence of HPV16/18 was detected in the 83 oral cancer cases by PCR analysis using HPV L1 consensus sequences, followed by Southern hybridization with type-specific oligonucleotide probes. Forty-six per cent (38/83) of oral cancer tumours showed p53 alterations, with 17% (14/83) showing point mutations, 37% (23/62) with overexpression and 25% (21/83) with presence of HPV16 wherein the E6 HPV16 protein degrades p53. HPV18 was not detected in any of the samples. Ninety-two per cent concordance was observed between missense point mutations and overexpression of p53 protein. A significant correlation was not observed between p53 alterations in oral cancer and clinico-pathological profile of the patients. Twenty-seven per cent (6/22) of oral leukoplakias showed p53 overexpression. The overall p53 alterations in oral cancer tissues and oral lesions are comparable to data from the oral cancers reported in the Western countries with smoking and alcohol-associated oral cancers, and suggest a critical role for p53 gene in a significant proportion of oral cancers from India. The overexpression of p53 protein in leukoplakias may serve as a valuable biomarker for identifying individuals at high risk of transformation to malignant phenotype.

Primary sternal osteomyelitis in infants: a report of two cases

Primary sternal osteomyelitis in infants, older children, and adults is rare. Secondary sternal osteomyelitis, however, is more common because of the increased frequency of cardiothoracic surgery and intravenous drug abuse. Primary sternal osteomyelitis is reviewed, two infants with further cases of primary sternal osteomyelitis are presented, and diagnosis and management are discussed.

Lateral thyrotomy for neurilemmoma of the larynx

We present a rare case of neurilemmoma of the larynx, which was excised through a lateral thyrotomy approach with resulting restoration of laryngeal function. The advantage of the lateral thyrotomy approach for submucous tumours of the larynx is discussed.

Perineural invasion and seminal vesicle involvement predict pelvic lymph node metastasis in men with localized carcinoma of the prostate

PURPOSE

We evaluate the contribution of perineural invasion and seminal vesicle biopsy results in predicting pelvic lymph node metastases in men with T1 or T2 adenocarcinoma of the prostate.

MATERIALS AND METHODS

A total of 212 men with localized prostate cancer were evaluated for serum prostate specific antigen (PSA), clinical stage, Gleason score and the presence of perineural invasion. Each patient had undergone seminal vesicle biopsies and a laparoscopic pelvic lymph node dissection before definitive therapy. The pretreatment prognostic values, presence of perineural invasion and seminal vesicle involvement were compared to the results of the laparoscopic pelvic lymph node dissection. Differences in proportions were tested using the Pearson chi-square test. The effect of multiple variables was tested using a stepwise logistic regression analysis.

RESULTS

PSA ranged from 1.6 to 190 ng./ml. (median 11), and 52% of patients had Gleason score 7 or greater and 67.5% had clinical stage T2b or greater disease. Of the 212 patients 37 (17.5%) had perineural invasion, 43 (20.3%) seminal vesicle involvement and 21 (10%) positive node dissections. A PSA greater than 20 ng./ml. (20 versus 6.8%, p = 0.006), Gleason score 7 or greater (15.5 versus 3.9%, p = 0.005), clinical stage T2b or greater (14 versus 0.6%, p = 0.004), presence of perineural invasion (27 versus 6%, p = 0.0001) and seminal vesicle involvement (32.6 versus 4.1%, p <0.0001) influenced nodal findings. However, in the logistic regression model only the positive seminal vesicle biopsy (p = 0.0006), presence of perineural invasion (p = 0.04) and PSA greater than 20 ng./ml. (p = 0.044) were significant variables. Of the 21 men with positive node dissections 18 (85.7%) had a positive seminal vesicle biopsy or perineural invasion. Separation of patients into a high risk group defined by a positive seminal vesicle biopsy or perineural invasion, or a low risk group defined as the absence of these features yielded a significant association with nodal involvement (28 versus 2%, p <0.0001). A separate analysis of the patients with a negative seminal vesicle biopsy demonstrated that only perineural invasion (19 versus 2%, p = 0.0002) and PSA greater than 20 ng./ml. (12 versus 2%, p = 0.01) conferred a greater risk of nodal metastases. A logistic regression analysis in the negative seminal vesicle biopsy group discarded all of the variables other than perineural invasion as significant.

CONCLUSIONS

A positive seminal vesicle biopsy is the most significant predictor of pelvic lymph node metastases in men with T1 or T2 prostate cancer. Perineural invasion is also an independent predictor of nodal disease. Patients with either of these features should undergo pelvic lymph node dissection before receiving definitive therapy.

Probing the structure of the nicotinic acetylcholine receptor with the hydrophobic photoreactive probes [125I]TID-BE and [125I]TIDPC/16

The hydrophobic photoreactive compound 3-trifluoromethyl-3-(m-[125I]iodophenyl) diazirine ([125I]TID) has revealed important structural information about the pore of the ion channel and lipid-protein interface of the nicotinic acetylcholine receptor (AChR). To further characterize the structure of the AChR, we have mapped the sites of photoincorporation of a benzoic acid ester analogue of TID ([125I]TID-BE) and a phospholipid analogue ([125I]TIDPC/16). For each photoreactive probe, labeled sites were identified by amino-terminal sequencing of purified tryptic fragments of individual receptor subunits. [125I]TID-BE reacted with alphaCys-412, alphaMet-415, and alphaCys-418 in the M4 segment of the alpha-subunit and gammaCys-451 and gammaSer-460 in gammaM4. In the M1 segment of the alpha- and beta-subunits, [125I]TID-BE labeled alphaPhe-227, alphaLeu-228, and betaLeu-234, betaAla-235, respectively. The labeling pattern in the M1 and M4 segments indicate that TID and TID-BE interact with the AChR lipid-protein interface in a similar fashion, revealing the same lipid-exposed face of each transmembrane segment. In contrast to TID, there was, however, no detectable incorporation of [125I]TID-BE into the channel lining betaM2 segment when the AChR was labeled in the resting state conformation. In the presence of agonist (desensitized state), [125I]TID-BE reacted with betaLeu-257, betaVal-261, and beta-Leu-264 in betaM2; a labeling pattern which indicates that, in comparison to TID, the binding loci for TID-BE is located closer to the extracellular end of the channel. For [125I]TIDPC/16, receptor labeling was insensitive to the presence of agonist and the sites of incorporation mapped to the confines of the transmembrane segments alphaM4, alphaM1, and gammaM4, validating previous results found with small lipophilic probes.

D2 gastrectomy: lessons from a prospective audit of the learning curve

A 3-year prospective study of the learning curve for D2 gastrectomy was carried out by one surgeon beginning to perform the operation independently after intensive specialist training. Some 38 patients were treated; there were four postoperative deaths and 22 patients had complications. Postoperative morbidity decreased significantly with time (rS = -0.38, P = 0.02, 95 per cent confidence interval -0.62 to -0.07). The physiological component of POSSUM (Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity) was significantly lower in the third year (median value 15, 16 and 14 for years 1, 2 and 3, n = 31, chi 2 = 7.5, 2 d.f., P = 0.02, Kruskal-Wallis test), but the operative POSSUM scores and the number of lymph nodes found were not decreased (median operative POSSUM score 19, 18 and 21, n = 31, chi 2 = 0.2, 2 d.f., P = 0.91, Kruskal-Wallis test). The results suggest a learning curve lasting about 18-24 months or 15 to 25 procedures before a plateau is reached. Improved results were associated with changes in case selection and operative tactics but not with reduced extent of lymphadenectomy. D2 gastrectomy should be restricted to specialist centres where adequate training and supervision can be provided during the learning curve.

Enhanced production of the chemotactic cytokines interleukin-8 and monocyte chemoattractant protein-1 in human abdominal aortic aneurysms

Inflammatory leukocytes play a central role in the pathogenesis of human atherosclerotic disease, from early atherogenesis to the late stages of atherosclerosis, such as aneurysm formation. We have shown previously that human abdominal aortic aneurysms are characterized by the presence of numerous chronic inflammatory cells throughout the vessel wall (Am J Pathol 1990, 137: 1199-1213). The signals that attract lymphocytes and monocytes into the aortic wall in aneurysmal disease remain to be precisely defined. We have studied the production of the chemotactic cytokines interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) by aortic tissues obtained from 47 subjects. We compared the antigenic production of these cytokines by explants of: 1) human abdominal aneurysmal tissue, 2) occlusive (atherosclerotic) aortas, and 3) normal aortas. IL-8, which is chemotactic for neutrophils, lymphocytes, and endothelial cells was liberated in greater quantities by abdominal aortic aneurysms than by occlusive or normal aortas. Using immunohistochemistry, macrophages, and to a lesser degree endothelial cells, were found to be positive for the expression of antigenic IL-8. Similarly, MCP-1, a potent chemotactic cytokine for monocytes/macrophages, was released by explants from abdominal aortic aneurysms in greater quantities than by explants from occlusive or normal aortas. Using immunohistochemistry, the predominant MCP-1 antigen-positive cells were macrophages and to a lesser extent smooth muscle cells. Our results indicate that human abdominal aortic aneurysms produce IL-8 and MCP-1, both of which may serve to recruit additional inflammatory cells into the abdominal aortic wall, hence perpetuating the inflammatory reaction that may result in the pathology of vessel wall destruction and aortic aneurysm formation.

Results of fundoplication in a UK paediatric centre

Of 55 children (age 3 months to 16 years) who had fundoplication, major complications occurred in nine (16 per cent): paraoesophageal hernia (five cases), prolonged ileus (two cases), recurrent gastro-oesophageal reflux (one case), and accidental perforation (one case). The single most important factor resulting in complications was the omission of crural repair; of seven patients without crural repair, five developed paraoesophageal hernia/recurrence. Four patients required repeat fundoplication for severe recurrent symptoms and one of these developed the unusual complication of pericardiogastric fistula. Thirteen patients had strictures before operation from reflux oesophagitis, six (46 per cent) resolved after fundoplication alone, six responded to dilatation (mean five sessions), and one required colon interposition. Our preliminary experience with balloon dilatation was encouraging: three of three patients responded after one dilatation only. These results confirmed the efficacy of surgery in controlling reflux: 100 per cent in the short-term and 89 per cent on a 1-6 year follow-up. Major complications might well be reduced by routine crural repair.

Disc embolization from a Beall mitral valve prosthesis

Although embolization of the disc from a Beall valve is rare, several reports in the literature have identified patients suffering this complication. This report details the clinical and radiologic course of a patient with an embolized disc from a Model 103 Beall mitral valve prosthesis. The patient lived approximately 39 hours without the disc prior to surgical correction. Depending on the cardiac reserve and the amount of pannus formation, patients may live long enough to allow surgical correction of this complication.