Hemin binding by Porphyromonas gingivalis strains is dependent on the presence of A-LPS.

Porphyromonas gingivalis is a Gram-negative black pigmenting anaerobe that is unable to synthesize heme [Fe(II)-protoporphyrin IX] or hemin [Fe(III)-protoporphyrin IX-Cl], which are important growth/virulence factors, and must therefore derive them from the host. Porphyromonas gingivalis expresses several proteinaceous hemin-binding sites, which are important in the binding/transport of heme/hemin from the host. It also synthesizes several virulence factors, namely cysteine-proteases Arg- and Lys-gingipains and two lipopolysaccharides (LPS), O-LPS and A-LPS. The gingipains are required for the production of the black pigment, µ-oxo-bisheme {[Fe(III)PPIX]2 O}, which is derived from hemoglobin and deposited on the bacterial cell-surface leading to the characteristic black colonies when grown on blood agar. In this study we investigated the role of LPS in the deposition of µ-oxo-bisheme on the cell-surface. A P. gingivalis mutant defective in the biosynthesis of Arg-gingipains, namely rgpA/rgpB, produces brown colonies on blood agar and mutants defective in Lys-gingipain (kgp) and LPS biosynthesis namely porR, waaL, wzy, and pg0129 (α-1, 3-mannosyltransferase) produce non-pigmented colonies. However, only those mutants lacking A-LPS showed reduced hemin-binding when cells in suspension were incubated with hemin. Using native, de-O-phosphorylated and de-lipidated LPS from P. gingivalis W50 and porR strains, we demonstrated that hemin-binding to O-polysaccharide (PS) and to the lipid A moiety of LPS was reduced compared with hemin-binding to A-PS. We conclude that A-LPS in the outer-membrane of P. gingivalis serves as a scaffold/anchor for the retention of µ-oxo-bisheme on the cell surface and pigmentation is dependent on the presence of A-LPS.

Evolution in techniques of laparoscopic pancreaticoduodenectomy: a decade long experience from a tertiary center.

BACKGROUND: Laparoscopic pancreaticoduodenectomy is a technically demanding surgery performed only at few centers in the world. This article aims to describe the evolution of the technique and summarizes the results in our institute over the years. METHODS: Prospective data of patients undergoing laparoscopic pancreaticoduodenectomy from March 1998 to January 2009 was retrospectively reviewed. RESULTS: There were a total of 75 patients (22 females and 53 males) with a mean age of 62 (range, 28-76) years. Conversion rate was 0%, overall postoperative morbidity was 26.7% and mortality rate was 1. 33%. Pancreatic fistula was seen in 6.67%. The mean operating time was 357 min (range 270-650), and the mean blood loss was 74 ml (range 35-410). The average time to the first bowel movement was 3 days and mean hospital stay was 8.2 days (range 6-42). Resected margins were positive in 2.6% of cases. The mean number of retrieved lymph nodes for the malignant lesions was 14 (range 8-22). CONCLUSION: Laparoscopic pancreaticoduodenectomy can be safely performed by highly skilled laparoscopic surgeons. This technique can achieve adequate margins and follow oncological principles. Randomized comparative trials are needed to establish the superiority of laparoscopy versus open surgery.

Laparoscopic repair of diastasis recti using the 'Venetian blinds' technique of plication with prosthetic reinforcement: a retrospective study.

BACKGROUND: Diastasis is a separation of the two recti due to various reasons, and can be measured as the 'inter-recti distance' (IRD). Surgery for diastasis is controversial, while laparoscopic repair has rarely been reported. We describe our method of laparoscopic plication-the 'Venetian blinds' technique combined with mesh reinforcement for patients with diastasis of the recti. MATERIALS AND METHODS: A total of 18 patients out of 35 that presented to us were operated. The common indications were cosmesis and discomfort while performing normal activities. Laparoscopic plication with the 'Venetian blinds' technique of the diastasis with prosthetic reinforcement was performed for all cases. RESULTS: The mean body mass index (BMI) was 28.6 kg/m(2) (range 25-32.2) and obese patients had a larger IRD. The mean operating time was 113 min (range 72-154). Minor complications were present in five (27.77%) patients. The recurrence rate after 6-48 months follow up was 0% in this series. DISCUSSION: Even though surgery for diastasis is controversial, we advocate repair for cosmesis and restoring function of the recti muscles. Our 'Venetian blinds' technique provides a solid repair and reduces the risk of seroma. The use of a prosthesis for the repair is mandatory to prevent recurrence. The adequacy of repair was assessed by measuring the IRD preoperatively and postoperatively with computed tomography (CT) scan. Laparoscopy provides all of the benefits of minimal access surgery.

Porphyromonas gingivalis stimulates TACE production by T cells.

INTRODUCTION: Tumour necrosis factor-alpha converting enzyme (TACE), also known as ADAM17, is a membrane-bound metalloprotease and disintegrin. It is produced by a number of host cells and is known to shed and release cell-bound cytokines, particularly members of the tumour necrosis factor family. The aim of this study was to investigate the effect of Porphyromonas gingivalis on TACE production by a human T-cell line, to identify putative virulence factors involved in this process, and to investigate the effect of doxycycline. METHODS: P. gingivalis 6-day culture supernatants were used to challenge Jurkat T cells for 6 h. Secreted and cell-associated TACE levels were measured by enzyme-linked immunosorbent assay, whereas messenger RNA expression was investigated by quantitative real-time polymerase chain reaction. To investigate the involvement of cysteine proteases or proteinaceous components in general, P. gingivalis culture supernatants were treated with the specific chemical inhibitor TLCK or heat-inactivated, respectively. The effect of doxycycline on the regulation of TACE secretion by P. gingivalis was also investigated. RESULTS: P. gingivalis challenge resulted in a concentration-dependent enhancement of TACE messenger RNA expression and protein release by Jurkat cells. TLCK treatment or heat treatment of P. gingivalis culture supernatants decreased TACE release to control levels. Doxycycline inhibited TACE secretion dose dependently. CONCLUSION: The induction of TACE by T cells in response to P. gingivalis may in turn favour the shedding of host cell-bound cytokines into the local microenvironment, potentially amplifying the inflammatory response. In the present experimental system, P. gingivalis cysteine proteases are involved in TACE release by T cells.

Porphyromonas gingivalis culture supernatants differentially regulate interleukin-1beta and interleukin-18 in human monocytic cells.

Porphyromonas gingivalis is a major bacterial species implicated in chornic periodontitis, a disease characterized by inflammatory destruction of the tooth supporting tissues. Its main virulence factors are lipopolysaccharide (LPS) and gingipains, a group of cysteine proteinases. Interleukin (IL)-18 is a potent pro-inflammatory cytokine with structural similarities to IL-1beta. This study aimed to investigate if P .gingivalis regulates IL-1beta and IL-18 in monocytic cells. Monomac-6 cells were challenged with P. gingivalis culture supernatants. Quantitative real-time PCR and ELISA were used to investigate IL-1beta and IL-18 mRNA expression and protein secretion, respectively. P. gingivalis enhanced IL-1beta and IL-18 mRNA expression, the former being induced earlier, but transiently. IL-18 up-regulation was not affected by P. gingivalis heat-inactivation or chemical inhibition of its gingipains, whereas both treatments resulted in 50% reduction of IL-1beta expression. Purified P. gingivalis LPS enhanced both IL-1beta and IL-18 expression. However, only IL-1beta, but not IL-18, secretion was detected, and was up-regulated by P. gingivalis. In conclusion, although IL-1beta and IL-18 belong to the same cytokine family, their gene expression and secretion are differentially regulated in human monocytic cells in response to P. gingivalis. Therefore, cytokines of the IL-1 family may participate via different pathways in the complex pathogenesis of periodontitis.

Laparoscopic repair of parahiatal hernias with mesh: a retrospective study.

BACKGROUND: Parahiatal hernias are very rare and distinct entities, the diagnosis of which is never made clinically. Laparoscopic repair has been reported in the literature. We present our experiences with the laparoscopic repair of this uncommon type of hernia. PATIENTS AND METHODS: In our institute, we retrospectively identified a total of eight patients with parahiatal hernias from 1999 to 2007, of which four had primary and four had secondary defects. Laparoscopic crural repair was performed for all of the patients, fundoplication wherever indicated and meshplasty in the cases with large defects. Gastropexy was performed for the patient with volvulus. RESULTS: The male:female ratio was 5:3, with a mean age of 46 years and a mean body mass index (BMI) of 29.3 kg/m2. The mean size of the defects was 18 cm2. The mean blood loss during surgery was 50 ml, the mean operative time was 103.5 min and the mean hospital stay was 4 days. One patient had the recurrence of symptoms 1 month after surgery. There were no conversions, recurrences or mortality. DISCUSSION: Primary parahiatal hernias occur as a result of a congenital weakness and secondary defects follow hiatal surgery. The use of a mesh is advisable for large defects and defects of primary type. Secondary hernias following fundoplication do not need a redo fundoplication, but require an adequate crural repair with mesh. Laparoscopic repair of these uncommon hernias is safe, effective and provides all of the benefits of minimally invasive surgery.

Transumbilical flexible endoscopic cholecystectomy in humans: first feasibility study using a hybrid technique.

BACKGROUND: Natural-orifice transluminal endoscopic surgery (NOTES) procedures have been tested using numerous approaches, mainly in animals. In humans, only cholecystectomy has been assessed, using a combined transvaginal and transumbilical approach. We present another variant of a hybrid technique for cholecystectomy, namely the combination of a flexible transumbilical double-channel endoscope and a 3-mm rigid transcutaneous trocar placed in the left hypochondrium for liver retraction. PATIENTS AND METHODS: The procedure was attempted in 10 well-selected young patients (M : F = 4 : 6, mean age 29.5 years). Instruments used through the two working channels of the endoscope were either a grasping forceps or snare for grasping and pulling and a hot-biopsy forceps for cold and hot preparation and dissection. Endoclips were used for cystic duct and artery closure. Postoperative analgesia consisted of one intravenous dose of analgesic, followed by oral administration for one further day. Follow-up visits were scheduled at 7 days, 30 days, 90 days, and 6 months. RESULTS: In 4 of the 10 cases the operation had to be converted to conventional laparoscopic cholecystectomy due to difficulty in dissection (in 2 cases) or uncontrollable hemorrhage (2 cases). The mean operating time was 148 minutes. Of the 6 cases in which the procedure was finished by the new approach, cystic artery bleeding occurred in 1 and was successfully clipped. One further patient had a postoperative cystic duct leak with a bilioma, successfully treated by endoscopic retrograde cholangiopancreatography with stenting. Five of the six patients reported themselves as satisfied at 3- or 6-month follow-up. CONCLUSIONS: So far, our endoscope-based transumbilical cholecystectomy technique has not yielded satisfactory results in humans. Further instrument and accessory improvements may increase both success rate and acceptance. Scarless surgery without the inherent risks of a transluminal approach may then become feasible.

Laparoscopic management of paraduodenal hernias: mesh and mesh-less repairs. A report of four cases.

BACKGROUND: Paraduodenal hernias are the most common form of internal hernias. There are few reports in the literature, with the total number of reported cases being less than 500. We report four patients with paraduodenal hernias causing intestinal obstruction. MATERIALS AND METHODS: All of the four patients with paraduodenal hernias presented with features of intestinal obstruction. A clinical diagnosis was not made in any of the cases, and computed tomography (CT) scanning was performed to confirm this. They were all successfully managed by a laparoscopic repair. RESULTS: The operating time was 55-72 mins. Postoperatively, three patients recovered uneventfully, while one patient had ileus for 3 days and, thereafter, recovered spontaneously. Hospital stay was in the range 2-6 days. There were no conversions. One patient had recurrent paraduodenal hernia, for which a laparoscopic mesh repair was successfully performed. DISCUSSION: The mechanism of the herniation is thought to be a defective rotation of the superior mesenteric vein during embryonic development. Paraduodenal hernias are not high on the list of differentials for bowel obstruction. Some form of surgery is mandatory for all cases. The inferior mesenteric vein has to be sacrificed in some cases to facilitate reduction of the hernia contents. A mesh repair is reserved for large defects and recurrent hernias. Laparoscopic repair has been infrequently reported in the literature. Based on our experience, the laparoscopic approach seems to be effective in the repair of paraduodenal hernias. It carries all of the benefits of minimal access surgery, while providing a sound repair.

Laparoscopic repair of suprapubic incisional hernias: suturing and intraperitoneal composite mesh onlay. A retrospective study.

BACKGROUND: Suprapubic hernias are those defects located 4 cm from the pubic symphysis. Our aim is to highlight the laparoscopic repair of suprapubic incisional hernias. PATIENTS AND METHODS: We retrospectively reviewed 17 patients with suprapubic incisional hernias from 1999 to 2007. A modified technique of laparoscopic intraperitoneal composite mesh onlay was performed for these patients. RESULTS: There were 12 females and 5 males with a mean age of 55.9 years and a mean BMI of 30 kg/m(2). The mean hernia size was 87.5 cm(2), with an average mesh size of 234 cm(2). Mean follow-up was 9 months. Complications were seen in five patients, with an overall recurrence rate of 5.8%. DISCUSSION: Suprapubic hernias are difficult to manage because of the complexity of dissection and their anatomic proximity to bony, vascular and nerve structures. The lower end of the mesh should be fixed to the Cooper's ligament and the pubic bone. Laparoscopic repair of these uncommon hernias is safe, effective and provides all the benefits of minimally invasive surgery.

Paraphimosis revisited: is chronic paraphimosis a predominantly third world condition?

Paraphimosis is an acute condition characterized by all the signs of inflammation. Here we describe a 'chronic' variant of paraphimosis where patients often present many days after the initial injury. The aim of this study is to identify and possibly classify this new variation of paraphimosis - the chronic condition. We studied 68 patients with this condition between 1997 and 2005. In all, the prepuce was fibrous and bunched up behind the glans penis and, in some cases, with ulcerations. All patients were treated by excision of the fibrous flap and circumcision, under local anaesthesia. Patients were discharged on the same day on which the excision was done. Follow-up was on the third, seventh and ninetieth days. Long-term follow-up was possible in only 22 patients. This technique of modified circumcision was effective in treating this condition and we think a new classification of paraphimosis is warranted - acute and chronic.

Laparoscopic transhiatal approach for benign supra-diaphragmatic lesions of the esophagus: a replacement for thoracoscopy?

Benign esophageal lesions are rare conditions and tumors account for about 10% of all esophageal neoplasms. Epiphrenic diverticula occur in the distal esophagus (the lower 10 cm). Currently, thoracotomy/thoracoscopy is the most popular approach for these conditions. We present our experience of 13 patients (1994-2006) with benign supra-diaphragmatic esophageal lesions that we treated with a laparoscopic transhiatal approach. The lesions included in the series were lower esophageal tumors (n = 8) and epiphrenic diverticula (n = 5). Laparoscopic transhiatal stapler excisions of diverticulum and enucleation of tumors were performed for all patients. Intra-operative endoscopy was used in all the procedures. All patients had an uneventful recovery except one with posterior diverticulum, who had an anastomotic leak. He had a prolonged hospital stay and recovered eventually. There was no mortality. Benign lesions of the lower third of the esophagus can be adequately treated through the transhiatal route. This is probably superior to the traditional approaches of thoracotomy/thoracoscopy as it does away with increased morbidity while maintaining adequate access. An endoscopy is of great value in localizing the lesion and assessing the esophageal lumen size during the application of staples. A laparoscopic transhiatal excision is technically feasible for all benign supra-diaphragmatic lesions and epiphrenic diverticula and is the approach of choice.

Laparoscopic surgery for an unusual case of dysphagia: lower oesophageal leiomyoma co-existing with achalasia cardia.

Benign tumours of the oesophagus are rare, with an incidence of ten percent. Leiomyomas are the most common benign tumours and are located frequently in the middle and lower third of the oesophagus. Coexisting achalasia cardia is very rare. We present a 63-year-old man with coexisting leiomyoma and achalasia presenting with dysphagia for 25 days. Endoscopy and manometry revealed achalasia cardia at the lower third. Barium swallow showed a tumour proximal to the narrowing. Laparoscopic transhiatal enucleation and cardiomyotomy with Toupet fundoplication was successfully performed. Several conditions have been described to coexist with achalasia cardia, such as cancer, paraoesophageal hernia and hiatal hernia. Based on our experience, we feel that lower oesophageal tumours are best approached by a laparoscopic transhiatal route and the presence of achalasia in this case did not change the approach as cardiomyotomy with fundoplication could also be simultaneously performed. Minimally-invasive surgery for benign oesophageal tumours reduces the morbidity of thoracotomy or laparotomy.

Laparoscopic mesh repair of a Bochdalek diaphragmatic hernia with acute gastric volvulus in a pregnant patient.

The advantages of minimally invasive therapy can be utilised in the surgical disorders of pregnant patients. To our knowledge, there has not been a previous report describing laparoscopic management of diaphragmatic hernia (with mesh) in pregnancy. A 23-year-old pregnant (second trimester) woman was admitted with vomiting, epigastric pain, oliguria and dyspnoea of one month duration. Investigations revealed posterolateral diaphragmatic hernia of Bochdalek with gastric volvulus. Successful laparoscopic mesh-plasty of the diaphragmatic hernia was performed without mortality or morbidity to both mother and child. Principles of laparoscopic surgery for diaphragmatic hernias remain the same. Pregnancy poses challenges to both surgeon and anaesthetist due to changes in the physiology. Acute diseases that threaten the life of mother and child have to be dealt with urgently. We conclude that even complex laparoscopic surgery during pregnancy is feasible.

Laparoscopic transperitoneal repair of lumbar incisional hernias: a combined suture and 'double-mesh' technique.

BACKGROUND: Lumbar hernias that occur after surgery are called lumbar incisional hernias. Recently, laparoscopic repair of these hernias has been reported with excellent outcomes. This is a retrospective study of our series of patients with lumbar incisional hernias. PATIENTS AND METHODS: We managed 11 patients with lumbar incisional hernias from 1996-2006. All the patients had undergone either nephrectomy or pyeloplasty in the past. Laparoscopic suturing of the defect and reinforcement with mesh were successfully performed for all the patients. RESULTS: There were more males than females, the age range was 42-65 years, and mean operating time was 120 min; discharge was at 1-2 postoperative days. There was no recurrence or mortality. Three cases had seroma, out of which two required aspiration after 60 days. DISCUSSION: Laparoscopic repair provides all the benefits of minimally invasive surgery, and the principles involved in repair of ventral hernias are applied in lumbar incisional hernias as well. Our technique involved suturing of the defect before placing a mesh over the defect. We theorize that approximating the ends of the muscles restores normal anatomy and results in functional improvement. For the larger hernias, we used two meshes to cover the defect--polypropylene and Parietex, sizes being 15 x 15 cm. CONCLUSION: Laparoscopic repair with prosthetic reinforcement is feasible and effective in the treatment of lumbar incisional hernias. Also, suturing of the defect may provide additional benefits.

Minimally invasive management of achalasia cardia: results from a single center study.

BACKGROUND: Since the performance of the first laparoscopic cardiomyotomy for achalasia cardia in 1991, the popularity of the minimally invasive approach for this troublesome disease has been growing. We present our experience of 226 patients who underwent laparoscopic cardiomyotomy and discuss the relevant issues. METHODS: A retrospective analysis was carried out of 226 patients who have undergone laparoscopic cardiomyotomy since 1993. The preoperative workup, surgical technique, and postoperative management are described. RESULTS: Patients included 146 males and 80 females; average age was 36.4 years (range, 6 to 85). Mean duration of symptoms was 1.4 years. Nearly half of the patients (112) had undergone prior pneumatic dilatation. In 20 patients, myotomy alone was done, 44 patients had a Dor's fundoplication, and 162 had Toupet's fundoplication. The average operating time was 96 minutes. Mean postoperative hospital stay was 2.2 days. Dysphagia was eliminated in 88.9% of the patients with an overall morbidity of 4.4% and nil mortality over a mean follow-up of 4.3 years. CONCLUSION: Laparoscopic cardiomyotomy with Toupet's fundoplication is a safe and effective treatment of achalasia cardia. Dor's fundoplication is done selectively, especially when suspicion is present of mucosal injury.

Porphyromonas gingivalis antagonises Campylobacter rectus induced cytokine production by human monocytes.

Porphyromonas gingivalis and Campylobacter rectus are two major bacterial species implicated in the pathogenesis of periodontitis. P. gingivalis can antagonise the inflammatory response to other periodontal pathogens, a property commonly attributed to its lipopolysaccharide (LPS). The aim of this study was to investigate the capacity of P. gingivalis to antagonise C. rectus induced cytokine stimulation from human monocytes, and to investigate the involvement of its LPS. Primary human monocytes and Monomac-6 cells were challenged with culture supernatants from P. gingivalis and C. rectus, and levels of IL-1beta, IL-6 and IL-8 produced were measured by ELISA after 6h incubation. Purified P. gingivalis LPS was also added alone or in combination with C. rectus culture supernatant. Both species significantly stimulated the production of all three cytokines from the two cell lines, but P. gingivalis was considerably weaker inducer. Co-stimulation of the cells with P. gingivalis and C. rectus suppressed the cytokine-stimulatory capacity of the latter. P. gingivalis LPS alone was sufficient to antagonise IL-6 and IL-8, but not IL-1beta stimulation by C. rectus. In conclusion, mixed infections may impair host immune responses by reducing pro-inflammatory cytokine levels, which may be of relevance to the pathogenesis of periodontitis.

Laparoscopic appendectomy for appendicitis in uncommon situations: the advantages of a tailored approach.

INTRODUCTION: Appendicitis in unusual locations or situations always poses a diagnostic dilemma and surgery is never straightforward. We aim to highlight the advantages of laparoscopy, including our own modifications, in some unusual presentations of appendicitis. METHODS: We treated a total of 7,210 patients with appendicitis over 14 years from 1992 to 2006. In this study, we included patients with subhepatic appendicitis (0.08 percent), appendectomy in midgut malrotation (0.09 percent), appendicitis in situs inversus totalis (0.01 percent) and appendicitis in the lateral pouch position (0.01 percent). All patients underwent laparoscopic appendectomy. RESULTS: Patients with subhepatic appendicitis, appendicitis in situs inversus and appendicitis in the lateral pouch position had an uneventful postoperative course. For the patients who underwent appendectomy as part of the treatment for malrotation and the patient with the perforated subhepatic appendix, hospital stay was slightly prolonged. CONCLUSION: Most patients in our study did not have a confirmed preoperative diagnosis. Diagnostic laparoscopy through the umbilical port helped confirm the diagnosis. Port positions were then planned according to the exact position of the appendix and the technique was modified to suit each individual patient. In the surgical scenarios described here, laparoscopy is invaluable in both diagnosis and treatment.

Laparoscopic management of iatrogenic high rectovaginal fistulas (Type VI).

Most rectovaginal fistulas are acquired. Obstetrical trauma and types of surgery such as laparoscopic-assisted vaginal hysterectomy may cause high rectovaginal fistulas. The high fistulas are repaired by abdominal approach, while middle or low fistulas are best approached perineally. There are not many reports of totally-laparoscopic repair available in the literature. We present two patients who had a (Type VI) high rectovaginal fistula following laparoscopicassisted vaginal hysterectomy. Laparoscopic repair was successfully performed by suturing the defects and fixing an omental patch between the rectum and vagina. The postoperative period was uneventful. Diagnosis and exact location of the fistula is critical in the management. Laparoscopic repair of high rectovaginal fistulas is feasible in most patients. Proper identification of tissue planes and good laparoscopic suturing technique is crucial for success. The issue of rectovaginal fistulas needs to be addressed in this era of laparoscopy, with particular reference to laparoscopy-assisted vaginal hysterectomy.

Laparoscopic surgery for perforation of Meckel's diverticulum.

We report an eight-year-old boy who presented with features of peritonitis and a vague mass in the periumbilical area. Initial clinical diagnosis was an appendicular abscess. Diagnostic laparoscopy revealed an inflammatory mass with pus due to a perforated Meckel's diverticulum. Laparoscopic stapler resection of the lesion was done and the patient recovered uneventfully. Surgical resection is indicated only if the diverticulum is symptomatic or if the base is narrow. Wedge resection of the diverticulum, including anterior wall of ileum, or stapler resection can be performed. Laparoscopy is useful in both diagnosis and treatment. Laparoscopic resection of Meckel's diverticulum is feasible and ideal, especially in specialised centres.