Mfge8 is expressed by pericytes in human gastric antrum submucosa from obese patients

The main function of the stomach is to digest ingested food. Gastric antrum muscular contractions mix ingested food with digestive enzymes and stomach acid and propel the chyme through the pyloric sphincter at a rate in which the small intestine can process the chyme for optimal nutrient absorption. Mfge8 binding to α8β1 integrins helps regulate gastric emptying by reducing the force of antral smooth muscle contractions. The source of Mfge8 within gastric muscles is unclear. Since Mfge8 is a secreted protein, Mfge8 could be delivered via the circulation, or be locally secreted by cells within the muscle layers. In this study we identify a source of Mfge8 within human gastric antrum muscles using spatial transcriptomic analysis. We show that Mfge8 is expressed in subpopulations of Mef2c+ perivascular cells within the submucosa layer of the gastric antrum. Mef2c is expressed in subpopulations of NG2+ and PDGFRB+ pericytes. Mfge8 is expressed in NG2+/Mef2c+ pericytes, but not in NG2+/Mef2c-, PDGFRB+/Mef2c-, or PDGFRB+/Mef2c+ pericytes. Mfge8 is absent from CD34+ endothelial cells but is expressed in a small population of perivascular ACTA2+ cells. We also show that α8 integrin is not expressed by ICC, supporting the findings that Mfge8 attenuates gastric antrum smooth muscle contractions by binding to α8β1 integrins on enteric smooth muscle cells. These findings suggest a novel, supplementary mechanism of regulation of gastric antrum motility by cellular regulators of capillary blood flow, in addition to the regulation of gastric antrum motility by the enteric nervous system and the SIP syncytium.

Spatiotemporal Control of Vascular CaV1.2 by α1C S1928 Phosphorylation

BACKGROUND

L-type CaV1.2 channels undergo cooperative gating to regulate cell function, although mechanisms are unclear. This study tests the hypothesis that phosphorylation of the CaV1.2 pore-forming subunit α1C at S1928 mediates vascular CaV1.2 cooperativity during diabetic hyperglycemia.

METHODS

A multiscale approach including patch-clamp electrophysiology, super-resolution nanoscopy, proximity ligation assay, calcium imaging' pressure myography, and Laser Speckle imaging was implemented to examine CaV1.2 cooperativity, α1C clustering, myogenic tone, and blood flow in human and mouse arterial myocytes/vessels.

RESULTS

CaV1.2 activity and cooperative gating increase in arterial myocytes from patients with type 2 diabetes and type 1 diabetic mice, and in wild-type mouse arterial myocytes after elevating extracellular glucose. These changes were prevented in wild-type cells pre-exposed to a PKA inhibitor or cells from knock-in S1928A but not S1700A mice. In addition, α1C clustering at the surface membrane of wild-type, but not wild-type cells pre-exposed to PKA or P2Y11 inhibitors and S1928A arterial myocytes, was elevated upon hyperglycemia and diabetes. CaV1.2 spatial and gating remodeling correlated with enhanced arterial myocyte Ca2+ influx and contractility and in vivo reduction in arterial diameter and blood flow upon hyperglycemia and diabetes in wild-type but not S1928A cells/mice.

CONCLUSIONS

These results suggest that PKA-dependent S1928 phosphorylation promotes the spatial reorganization of vascular α1C into "superclusters" upon hyperglycemia and diabetes. This triggers CaV1.2 activity and cooperativity, directly impacting vascular reactivity. The results may lay the foundation for developing therapeutics to correct CaV1.2 and arterial function during diabetic hyperglycemia.

The identification of neuronal control pathways supplying effector tissues in the stomach

The stomach acts as a buffer between the ingestion of food and its processing in the small intestine. It signals to the brain to modulate food intake and it in turn regulates the passage of a nutrient-rich fluid, containing partly digested food, into the duodenum. These processes need to be finely controlled, for example to restrict reflux into the esophagus and to transfer digesta to the duodenum at an appropriate rate. Thus, the efferent pathways that control gastric volume, gastric peristalsis and digestive juice production are critically important. We review these pathways with an emphasis on the identities of the final motor neurons and comparisons between species. The major types of motor neurons arising from gastric enteric ganglia are as follows: immunohistochemically distinguishable excitatory and inhibitory muscle motor neurons; four neuron types innervating mucosal effectors (parietal cells, chief cells, gastrin cells and somatostatin cells); and vasodilator neurons. Sympathetic efferent neurons innervate intramural arteries, myenteric ganglia and gastric muscle. Vagal efferent neurons with cell bodies in the brain stem do not directly innervate gastric effector tissues; they are pre-enteric neurons that innervate each type of gastric enteric motor neuron. The principal transmitters and co-transmitters of gastric motor neurons, as well as key immunohistochemical markers, are the same in rat, pig, human and other species.

AKAP5 complex facilitates purinergic modulation of vascular L-type Ca2+ channel CaV1.2

The L-type Ca2+ channel CaV1.2 is essential for arterial myocyte excitability, gene expression and contraction. Elevations in extracellular glucose (hyperglycemia) potentiate vascular L-type Ca2+ channel via PKA, but the underlying mechanisms are unclear. Here, we find that cAMP synthesis in response to elevated glucose and the selective P2Y11 agonist NF546 is blocked by disruption of A-kinase anchoring protein 5 (AKAP5) function in arterial myocytes. Glucose and NF546-induced potentiation of L-type Ca2+ channels, vasoconstriction and decreased blood flow are prevented in AKAP5 null arterial myocytes/arteries. These responses are nucleated via the AKAP5-dependent clustering of P2Y11/ P2Y11-like receptors, AC5, PKA and CaV1.2 into nanocomplexes at the plasma membrane of human and mouse arterial myocytes. Hence, data reveal an AKAP5 signaling module that regulates L-type Ca2+ channel activity and vascular reactivity upon elevated glucose. This AKAP5-anchored nanocomplex may contribute to vascular complications during diabetic hyperglycemia.

Large Hiatal Hernia Repair with Urinary Bladder Matrix Graft Reinforcement and Concomitant Sleeve Gastrectomy

Background:

There is no current consensus on the management of large hiatal hernias concomitant with performance of a sleeve gastrectomy procedure. Proposed solutions have included performing a modified Nissen fundoplication, performing cruroplasty alone, utilizing the Linx device, performing cruroplasty with reinforcement material, and avoiding the sleeve procedure altogether in favor of a bypass procedure in order to minimize gastroesophageal reflux. Urinary bladder matrix (UBM) represents a biologically derived material for use in hiatal hernia repair reinforcement with the potential to improve durability of repair without incurring the risks of other reinforcement materials.

Methods:

This study reports the results of a retrospective chart review of 32 cases of large hiatal hernia repair utilizing both primary crural repair and UBM reinforcement concomitant with laparoscopic sleeve gastrectomy by a single surgeon. Hernia diameter averaged 6 cm (range 4–9 cm). After an average of 1 year followup, 30 patients were assessed for subjective symptoms of gastroesophageal reflux (GERD) using the Gastroesophageal Reflux Disease-Health Related Quality of Life (GERD-HRQL) score. Twenty patients were evaluated with either upper gastrointestinal (GI) series, endoscopy, or both.

Results:

Each repair was successful and completed laparoscopically concomitant with sleeve gastrectomy. Anterior and posterior cruroplasty was performed using interrupted 0-Ethibond suture using the Endostitch device. The UBM graft exhibited favorable handling characteristics placed as a keyhole geometry sutured to the crura with absorbable suture. A careful chart review was undertaken to assess for complications. There have been no reoperations. After a median of 12 months (range, 4–27 months) of followup, an assessment of recurrences or long-term complications was completed. Median GERD-HRQL score was 6, with a range of 0 to 64 (of possible 75), indicating very low-level reflux symptomatology. Follow-up upper GI radiographs or endoscopy were obtained in 20 cases and show intact repairs.

Conclusion:

In this series of 32 cases, laparoscopic cruroplasty with UBM graft reinforcement has been effective and durable at 12 months of followup. This technique may offer one satisfactory solution for large hiatal hernia repair concomitant with laparoscopic sleeve gastrectomy that may achieve a durable repair with low GERD symptoms.

A Gs-coupled purinergic receptor boosts Ca2+ influx and vascular contractility during diabetic hyperglycemia

Elevated glucose increases vascular reactivity by promoting L-type Ca_V1.2 channel (LTCC) activity by protein kinase A (PKA). Yet, how glucose activates PKA is unknown. We hypothesized that a G_s-coupled P2Y receptor is an upstream activator of PKA mediating LTCC potentiation during diabetic hyperglycemia. Experiments in apyrase-treated cells suggested involvement of a P2Y receptor underlying the glucose effects on LTTCs. Using human tissue, expression for P2Y₁₁, the only G_s-coupled P2Y receptor, was detected in nanometer proximity to Ca_V1.2 and PKA. FRET-based experiments revealed that the selective P2Y₁₁ agonist NF546 and elevated glucose stimulate cAMP production resulting in enhanced PKA-dependent LTCC activity. These changes were blocked by the selective P2Y₁₁ inhibitor NF340. Comparable results were observed in mouse tissue, suggesting that a P2Y₁₁-like receptor is mediating the glucose response in these cells. These findings established a key role for P2Y₁₁ in regulating PKA-dependent LTCC function and vascular reactivity during diabetic hyperglycemia.

Relationships of endocrine cells to each other and to other cell types in the human gastric fundus and corpus

Gastric endocrine cell hormones contribute to the control of the stomach and to signalling to the brain. In other gut regions, enteroendocrine cells (EECs) exhibit extensive patterns of colocalisation of hormones. In the current study, we characterise EECs in the human gastric fundus and corpus. We utilise immunohistochemistry to investigate EECs with antibodies to ghrelin, serotonin (5-HT), somatostatin, peptide YY (PYY), glucagon-like peptide 1, calbindin, gastrin and pancreastatin, the latter as a marker of enterochromaffin-like (ECL) cells. EECs were mainly located in regions of the gastric glands populated by parietal cells. Gastrin cells were absent and PYY cells were very rare. Except for about 25% of 5-HT cells being a subpopulation of ECL cells marked by pancreastatin, colocalisation of hormones in gastric EECs was infrequent. Ghrelin cells were distributed throughout the fundus and corpus; most were basally located in the glands, often very close to parietal cells and were closed cells i.e., not in contact with the lumen. A small proportion had long processes located close to the base of the mucosal epithelium. The 5-HT cells were of at least three types: small, round, closed cells; cells with multiple, often very long, processes; and a subgroup of ECL cells. Processes were in contact with their surrounding cells, including parietal cells. Mast cells had very weak or no 5-HT immunoreactivity. Somatostatin cells were a closed type with long processes. In conclusion, four major chemically defined EEC types occurred in the human oxyntic mucosa. Within each group were cells with distinct morphologies and relationships to other mucosal cells.

Long-term clinical, radiological, and histological follow-up after complex ventral incisional hernia repair using urinary bladder matrix graft reinforcement: a retrospective cohort study

Background

Complex ventral incisional hernia repair represents a challenging clinical condition in which biologically derived graft reinforcement is often utilized, but little long-term data inform that decision. Urinary bladder matrix (UBM) has shown effectiveness in diverse clinical settings as durable reinforcement graft material, but it has not been studied over a long term in ventral incisional hernia repair. This study evaluates the clinical, radiographic, and histological outcome of complex incisional hernia repair using UBM reinforcement with 12–70 months of follow-up.

Methods

A single-arm, retrospective observational study of all ventral incisional hernia repairs utilizing UBM reinforcement over a 6-year time frame by a single surgeon was performed. Patients were assessed in long-term follow-up clinically and with the Carolina Comfort Scale. A subset of patients was assessed with abdominal wall ultrasound or CT scan. Three patients had abdominal wall fascial biopsies years after the incisional hernia repair with UBM graft, and the histology is analyzed.

Results

64 patients underwent repair of complex incisional hernias with UBM graft reinforcement by a single surgeon. 42 patients had concomitant procedures including large or small bowel resection, excision of infected mesh, evacuation of abscess or hematoma, cholecystectomy, or panniculectomy with abdominoplasty. 16 patients had ostomies at the time of repair. Median follow-up time is 36 months, with a range of 12–70 months. Nine patients (14%) have required surgical repair of a recurrent hernia, and a tenth patient has a recurrence that is managed non-surgically, for a total recurrence rate of 15.6% over the entire time frame. Median time to recurrence was 32 months, and a Kaplan–Meier freedom from recurrence curve is depicted. 28 patients have undergone ultrasound or CT assessments of the abdominal wall which demonstrate radiographic fascial integrity 12–70 months after repair. Three patients have been re-explored for unrelated reasons in the years following ventral incisional hernia repair with UBM, and full thickness fascial biopsies demonstrate a robust remodeling response histologically similar to native myofascial tissue. No patients have developed graft infection, fistulization to the graft, or required graft explantation. Carolina Comfort Scale assessment of 45 patients 3 years after the repair averaged 16 out of a possible 115.

Conclusion

In 64 patients undergoing complex ventral incisional hernia repair with UBM reinforcement, all have experienced successful resolution of complex clinical conditions and 15.6% of these repairs have recurred at a median follow-up of 3 years. Three full-thickness biopsies of the repaired fascia years later shed light on a promising remodeling response which may signal strength and durability comparable to native fascia.

DNA methylation, through DNMT1, has an essential role in the development of gastrointestinal smooth muscle cells and disease

DNA methylation is a key epigenetic modification that can regulate gene expression. Genomic DNA hypomethylation is commonly found in many gastrointestinal (GI) diseases. Dysregulated gene expression in GI smooth muscle cells (GI-SMCs) can lead to motility disorders. However, the consequences of genomic DNA hypomethylation within GI-SMCs are still elusive. Utilizing a Cre-lox murine model, we have generated SMC-restricted DNA methyltransferase 1 (Dnmt1) knockout (KO) mice and analyzed the effects of Dnmt1 deficiency. Dnmt1-KO pups are born smaller than their wild-type littermates, have shortened GI tracts, and lose peristaltic movement due to loss of the tunica muscularis in their intestine, causing massive intestinal dilation, and death around postnatal day 21. Within smooth muscle tissue, significant CpG hypomethylation occurs across the genome at promoters, introns, and exons. Additionally, there is a marked loss of differentiated SMC markers (Srf, Myh11, miR-133, miR-143/145), an increase in pro-apoptotic markers (Nr4a1, Gadd45g), loss of cellular connectivity, and an accumulation of coated vesicles within SMC. Interestingly, we observed consistent abnormal expression patterns of enzymes involved in DNA methylation between both Dnmt1-KO mice and diseased human GI tissue. These data demonstrate that DNA hypomethylation in embryonic SMC, via congenital Dnmt1 deficiency, contributes to massive dysregulation of gene expression and is lethal to GI-SMC. These results suggest that Dnmt1 has a necessary role in the embryonic, primary development process of SMC with consistent patterns being found in human GI diseased tissue.

Contractile Protein Expression and Phosphorylation and Contractility of Gastric Smooth Muscles from Obese Patients and Patients with Obesity and Diabetes

Ingested food is received, mixed, and ground into chyme by distinct gastric motility patterns. Diabetes impairs gastric muscle function, but the mechanisms underlying diabetes-induced gastric muscle dysfunction are unknown. Here, we compared the expression and phosphorylation of Ca²⁺ sensitization and contractile proteins in human gastric muscles from obese nondiabetic and diabetic patients. We also compared the spontaneous phasic contractions and the contractile responses evoked by electrical field stimulation of cholinergic motor neurons. Fundus and antrum muscles were obtained from sleeve gastrectomies and were used in in vitro myobath contractile studies and for capillary electrophoresis and immunodetection of γ-actin, CPI-17, pT38-CPI-17, MYPT1, pT853-MYPT1, pT696-MYPT1, myosin light chain (MYL9), pS19-MYL9, myosin light chain kinase (MYLK), protein phosphatase-1δ (PP1δ), and Rho-associated kinase (ROCK2). In diabetic fundus muscles, MYLK, ROCK2, and PP1δ expression was unchanged; MYPT1 and CPI-17 expression was decreased; and the pT853/MYPT1 and pT38/CPI-17 ratios, but not the pT696/MYPT1 ratio, were increased. Although MYL9 expression was increased, the pS19/MYL9 ratio was unchanged in diabetic fundus muscles. In diabetic antrum muscles, MYLK and MYL9 expression was unchanged, but ROCK2, CPI-17, and PP1δ expression was decreased. The pT38/CPI-17 ratio was unchanged, while the pS19/MYL9, pT853/MYPT1, and pT696/MYPT1 ratios were decreased, consistent with the reduced ROCK2 expression. The frequencies of spontaneous phasic contractions from nondiabetic and diabetic gastric fundus and antrum muscles did not significantly differ from each other, regardless of age, sex, or diabetic status. The fold increases in the contractions of diabetic fundus and antrum muscles in response to increased frequencies of electrical field stimulation were significantly lower compared to nondiabetic fundus and antrum muscles. The altered contractile responses and the protein expression and phosphorylation in gastric muscles of obese patients with diabetes illustrate the importance of understanding how smooth muscle Ca²⁺ sensitization mechanisms contribute to gastric motility.

Loss of nitric oxide-mediated inhibition of purine neurotransmitter release in the colon in the absence of interstitial cells of Cajal

Regulation of colonic motility depends on the integrity of enteric inhibitory neurotransmission mediated by nitric oxide (NO), purine neurotransmitters, and neuropeptides. Intramuscular interstitial cells of Cajal (ICC-IM) and platelet-derived growth factor receptor-α-positive (PDGFRα⁺) cells are involved in generating responses to NO and purine neurotransmitters, respectively. Previous studies have suggested a decreased nitrergic and increased purinergic neurotransmission in Kit^W/Kit^W-v (W/W^v ) mice that display lesions in ICC-IM along the gastrointestinal tract. However, contributions of NO to these phenotypes have not been evaluated. We used small-chamber superfusion assays and HPLC to measure the spontaneous and electrical field stimulation (EFS)-evoked release of nicotinamide adenine dinucleotide (NAD⁺)/ADP-ribose, uridine adenosine tetraphosphate (Up4A), adenosine 5'-triphosphate (ATP), and metabolites from the tunica muscularis of human, monkey, and murine colons and circular muscle of monkey colon, and we tested drugs that modulate NO levels or blocked NO receptors. NO inhibited EFS-evoked release of purines in the colon via presynaptic neuromodulation. Colons from W/W^v, Nos1^-/- , and Prkg1^-/- mice displayed augmented neural release of purines that was likely due to altered nitrergic neuromodulation. Colons from W/W^v mice demonstrated decreased nitrergic and increased purinergic relaxations in response to nerve stimulation. W/W^v mouse colons demonstrated reduced Nos1 expression and reduced NO release. Our results suggest that enhanced purinergic neurotransmission may compensate for the loss of nitrergic neurotransmission in muscles with partial loss of ICC. The interactions between nitrergic and purinergic neurotransmission in the colon provide novel insight into the role of neurotransmitters and effector cells in the neural regulation of gastrointestinal motility.NEW & NOTEWORTHY This is the first study investigating the role of nitric oxide (NO) and intramuscular interstitial cells of Cajal (ICC-IM) in modulating neural release of purines in colon. We found that NO inhibited release of purines in human, monkey, and murine colons and that colons from Kit^W/Kit^W-v (W/W^v ) mice, which present with partial loss of ICC-IM, demonstrated augmented neural release of purines. Interactions between nitrergic and purinergic neurotransmission may affect motility in disease conditions with ICC-IM deficiencies.

Laparoscopic Rectopexy with Urinary Bladder Xenograft Reinforcement

BACKGROUND AND OBJECTIVES

Rectal prolapse is often repaired laparoscopically, frequently with the use of reinforcement material. Both synthetic and biologically derived materials reduce recurrence rate compared to primary suture repair. Synthetic mesh introduces potential complications such as mesh erosion, fibrosis, and infection. Urinary bladder matrix (UBM) represents a biologically derived material for reinforcement of rectal prolapse repair with the potential to improve durability without risks of synthetic materials. The objective of the study is to evaluate the effectiveness, durability, and functional result of laparoscopic rectopexy using urinary bladder matrix xenograft reinforcement at three years follow up.

METHODS

The 20 cases presented describe rectal prolapse repair by means of laparoscopic rectopexy with presacral UBM reinforcement. Patients were followed up for an average of 3 years and assessed with interviews, physical examination, manometry, and the fecal incontinence severity index (FISI).

RESULTS

Each repair was completed laparoscopically. UBM exhibited favorable handling characteristics when sutured to the sacrum and the lateral rectal walls. One patient underwent laparoscopic drainage of a postoperative abscess; no other complications occurred. In 3 years of follow-up, there have been no full-thickness recurrences, erosions, reoperations, or long-term complications. Two patients exhibited a small degree of mucosal prolapse on follow-up physical examination that did not require surgery. Three-year FISI scores averaged 8 (range, 0-33 of a possible 61), indicating low fecal incontinence symptomatology. Follow-up anorectal manometry was performed in 9 patients, showing mixed results.

CONCLUSION

Surgeons may safely use laparoscopic rectopexy with UBM reinforcement for repair of rectal prolapses. In this series, repairs with UBM grafts have been durable at 3-year follow-up and may be an alternative to synthetic mesh reinforcement of rectal prolapse repairs. Future studies may compare the advantages and cost-effectiveness of reinforcement materials for rectal prolapse repair.

Hiatal Hernia Repair with Novel Biological Graft Reinforcement

Background and Objectives:

Hiatal hernias are repaired laparoscopically with increasing use of reinforcement material. Both synthetic and biologically derived materials reduce the recurrence rate compared to primary crural repair. Synthetic mesh introduces complications, such as mesh erosion, fibrosis, and infection. Urinary bladder matrix (UBM) represents a biologically derived material for use in hiatal hernia repair reinforcement with the potential to improve durability of repair without incurring the risks of other reinforcement materials.

Methods:

The 15 cases presented involved hiatal hernia repair with primary crural repair with UBM reinforcement and fundoplication. Patients were followed for an average of 3 years, and were assessed with upper gastrointestinal (GI) series, endoscopy, and assessments of subjective symptoms of gastroesophageal reflux disease (GERD).

Results:

Hernia diameters averaged 6 cm. Each repair was successful and completed laparoscopically. UBM exhibited favorable handling characteristics when placed as a horseshoe-type graft sutured to the crura. One patient underwent endoscopic balloon dilatation of a mild postoperative stenosis that resolved. No other complications occurred. In more than 3 years of follow-up, there have been no recurrences or long-term complications. GERD-health-related quality of life (HRQL) scores averaged 6 (range, 0–12, of a possible 50), indicating little reflux symptomatology. Follow-up upper GI series were obtained in 9 cases and showed intact repairs. An upper endoscopy was performed in 8 patients and showed no recurrences.

Conclusion:

Surgeons may safely use laparoscopic fundoplication with UBM reinforcement for successful repair of hiatal hernias. In this series, repairs with UBM grafts have been durable at 3 years of follow-up and may serve as an alternative to synthetic mesh reinforcement of hiatal hernia repairs.

Ser1928 phosphorylation by PKA stimulates the L-type Ca2+ channel CaV1.2 and vasoconstriction during acute hyperglycemia and diabetes

Hypercontractility of arterial myocytes and enhanced vascular tone during diabetes are, in part, attributed to the effects of increased glucose (hyperglycemia) on L-type Ca_V1.2 channels. In murine arterial myocytes, kinase-dependent mechanisms mediate the increase in Ca_V1.2 activity in response to increased extracellular glucose. We identified a subpopulation of the Ca_V1.2 channel pore-forming subunit (α1_C) within nanometer proximity of protein kinase A (PKA) at the sarcolemma of murine and human arterial myocytes. This arrangement depended upon scaffolding of PKA by an A-kinase anchoring protein 150 (AKAP150) in mice. Glucose-mediated increases in Ca_V1.2 channel activity were associated with PKA activity, leading to α1_C phosphorylation at Ser¹⁹²⁸ Compared to arteries from low-fat diet (LFD)-fed mice and nondiabetic patients, arteries from high-fat diet (HFD)-fed mice and from diabetic patients had increased Ser¹⁹²⁸ phosphorylation and Ca_V1.2 activity. Arterial myocytes and arteries from mice lacking AKAP150 or expressing mutant AKAP150 unable to bind PKA did not exhibit increased Ser¹⁹²⁸ phosphorylation and Ca_V1.2 current density in response to increased glucose or to HFD. Consistent with a functional role for Ser¹⁹²⁸ phosphorylation, arterial myocytes and arteries from knockin mice expressing a Ca_V1.2 with Ser¹⁹²⁸ mutated to alanine (S1928A) lacked glucose-mediated increases in Ca_V1.2 activity and vasoconstriction. Furthermore, the HFD-induced increases in Ca_V1.2 current density and myogenic tone were prevented in S1928A knockin mice. These findings reveal an essential role for α1_C phosphorylation at Ser¹⁹²⁸ in stimulating Ca_V1.2 channel activity and vasoconstriction by AKAP-targeted PKA upon exposure to increased glucose and in diabetes.

Accelerated healing of complex open pilonidal wounds using MatriStem extracellular matrix xenograft: nine cases

Complex open pilonidal wounds represent a challenging wound healing problem. Nine cases of complex open pilonidal wounds are described. Each of them was treated at the time of primary wide excision with placement of xenograft extracellular matrix material derived from urinary bladder (MatriStem, ACell Corporation). The patients left the xenograft material and dressings intact and returned to our clinic at weekly intervals for inspection of the wounds. All of the cases of complex open pilonidal wounds healed without infection and without requiring re-operation. The average time to healing in this series was 7 weeks. Treatment of complex open pilonidal wounds with MatriStem extracellular matrix derived from urinary bladder in this fashion results in favorable wound healing of complex open pilonidal wounds.

Long-term durability and comfort of laparoscopic ventral hernia repair

The authors contend that laparoscopic radical trachelectomy with pelvic lymphadenectomy for early-stage cervical cancer may be an alternative technique for this disease in developing countries.

Introduction:

The standard treatment for patients with early-stage cervical cancer has been radical hysterectomy. However, for women interested in future fertility, radical trachelectomy is now considered a safe and feasible option. The use of minimally invasive surgical techniques to perform this procedure has recently been reported.

Case Description:

We report the first case of a laparoscopic radical trachelectomy performed in a developing country. The patient is a nulligravid, 30-y-old female with stage IB1 adenocarcinoma of the cervix who desired future fertility. She underwent a laparoscopic radical trachelectomy and bilateral pelvic lymph node dissection. The operative time was 340 min, and the estimated blood loss was 100mL. There were no intraoperative or postoperative complications. The final pathology showed no evidence of residual disease, and all pelvic lymph nodes were negative. At 20 mo of follow-up, the patient is having regular menses but has not yet attempted to become pregnant. There is no evidence of recurrence.

Conclusion:

Laparoscopic radical trachelectomy with pelvic lymphadenectomy in a young woman who desires future fertility may also be an alternative technique in the treatment of early cervical cancer in developing countries.

Long-term durability and comfort of laparoscopic ventral hernia repair

BACKGROUND

Repair of ventral hernias, including primary ventral hernias and incisional ventral hernias, is performed in the United States 90,000 times per year. Open or traditional ventral hernia repairs involve the significant morbidity and expense of a laparotomy and a significant risk of recurrent herniation. Laparoscopic ventral hernia repair (LVHR) may offer a less-invasive alternative with shorter length of hospital stay, fewer cardiopulmonary complications, and low recurrence rates.

METHODS

225 patients underwent laparoscopic ventral hernia repairs in which carboxymethylcellulose-sodium hyaluronate coating (Sepramesh, Davol, Providence, RI) was used primarily. All cases were included prospectively from the study period of 2002 through 2009. Patient characteristics were recorded, and follow-up analysis was performed over a period of 42 mo following surgery. Recurrence, reoperations, and all complications were recorded. Mesh awareness and mesh-related pain were assessed using the hernia-specific Carolinas Comfort Scale (CCS) instrument, completed by 72 patients.

RESULTS

Over 42 mo of follow-up, 2 ventral hernias have recurred, and no long-term bowel erosion or fistulization has occurred. Little or no mesh-related symptoms were reported, and mean scores for mesh awareness and mesh pain were 3.6 and 3.2, respectively, on a scale from 0 - 40 (lower scores signify less pain or awareness). Two serious early complications occurred related to intestinal ileus and metal tacks producing intestinal perforation, and this led to a change in the tacking devices used.

CONCLUSIONS

LVHR with carboxymethylcellulose-sodium hyaluronate coating (Sepramesh) is safe and effective. Complications are rare, the repair is durable, and long-term results are good with rare recurrences, low awareness of mesh, and little pain. Technical lessons include use of at least one transfascial suture and the avoidance of metal tacks for fixation.

Outpatient weight loss surgery: initiating a gastric bypass and gastric banding ambulatory weight loss surgery center

BACKGROUND

Ambulatory surgery or outpatient surgery is becoming increasingly common. In 2002, 63% of all operations performed in the United States were ambulatory procedures. Bariatric procedures performed in the United States have increased from 16,200 in 1992 to approximately 205,000 in 2007. In 2002, our center began offering laparoscopic Roux-en-Y gastric bypass (LRYGB) procedures on an outpatient basis for select candidates at an ambulatory surgery center (ASC). We subsequently added laparoscopic adjustable gastric band procedures (LAGB) in 2005.

METHODS

Between 2002 and 2008, 248 LRYGB and LAGB patients were carefully selected for ASC surgery by the bariatric surgeon and medical director. Extensive preoperative education was mandatory for all surgical candidates.

RESULTS

Since 2002, we have performed 248 bariatric cases at the ASC, including 38 LRYGB and 210 LAGB procedures. In this overall experience, 5 patients (2%) required readmission within 30 days of surgery, and 98.6% of LAGB patients were discharged the same day; 62% were discharged after a 4-hour to 6-hour stay in the ASC. All LRYGB patients remained in the ASC overnight and were discharge within 24 hours of their procedure. Weight loss results have been excellent.

CONCLUSION

LAGB surgery can be safely performed in an ASC setting in most patients. LRYGB can be performed safely in the ASC setting with careful scrutiny and cautious selection of patient candidates.

Seven cases of gastric perforation in Roux-en-Y gastric bypass patients: what lessons can we learn?

BACKGROUND

Patients undergoing Roux-en-Y gastric bypass for the resolution of morbid obesity have significant medical sequelae related to their weight. One of the most common comorbid conditions is joint pain requiring the use of non-steroidal anti-inflammatory medications (NSAIDs). In addition to NSAIDs, patients may engage in behaviors such as smoking and alcohol misuse that increase the risk of long-term postoperative complications to include gastric perforation.

METHODS

Data on 1,690 patients undergoing gastric bypass surgery were collected prospectively and reviewed retrospectively.

RESULTS

We identified seven patients who presented to an emergency room and subsequently required emergent surgical intervention for repair of gastric perforation. Six of the seven cases involved use or abuse of NSAIDs.

CONCLUSION

Important characteristics were identified including the use of NSAIDs, alcohol use, and non-compliance with routine long-term postoperative follow-up. Identifying those patients at high risk may decrease the incidence of this potentially life-threatening complication.

Giant tumors of the chest: preoperative embolization and resection

Giant tumors of the chest are rare. These tumors comprise a spectrum of disease from benign lesions to highly aggressive malignant tumors with cells of origin in the pleura, pulmonary parenchyma, blood vessels, thymus, and connective tissues. We report four cases of giant tumors of the thorax treated with preoperative arterial embolization followed by complete surgical resection. Their diagnostic and treatment courses, imaging, and pathology are described.

Positron emission tomography with f18-fluorodeoxyglucose in the staging and preoperative evaluation of malignant pleural mesothelioma

OBJECTIVES

The purpose of this study was to evaluate the utility of positron emission tomography with F18-fluorodeoxyglucose in the preoperative evaluation and staging of malignant mesothelioma in patients who were candidates for aggressive combined modality therapy.

METHODS

Eighteen consecutive patients with biopsy-proven malignant mesothelioma underwent positron emission tomographic scanning. The results of positron emission tomographic imaging were compared with results obtained by computed tomography, mediastinoscopy, thoracoscopy, and pathologic examination of surgical specimens. All patients fasted and received an average of 14.5 +/- 2.7 mCi of F18-fluorodeoxyglucose for positron emission tomographic scanning. Attenuation-corrected whole-body and regional emission images of the chest and upper abdomen were acquired and formatted into transaxial, coronal, and sagittal images.

RESULTS

All primary malignant mesotheliomas accumulated F18-fluorodeoxyglucose, and the mean standardized uptake value was 7. 6 (range, 3.33-14.85; n = 9). There were no false-negative results of positron emission tomography. Identification of occult extrathoracic metastases by positron emission tomography was the basis for excluding two patients from surgical therapy. There were two false-positive results of positron emission tomography: increased F18-fluorodeoxyglucose uptake in the contralateral chest that was negative by thoracoscopic biopsy (n = 1) and increased abdominal F18-fluorodeoxyglucose uptake after partial colectomy for diverticular disease (n = 1).

CONCLUSIONS

Positron emission tomography can identify malignant pleural mesothelioma and appears to be a useful noninvasive staging modality for patients being considered for aggressive combined modality therapy.

Long-term survival after intensive care unit admission with sepsis

OBJECTIVE

To evaluate the long-term survival of critically ill patients with sepsis and to assess the factors predictive of long-term survival (> 1 month after admission date).

DESIGN

Prospective, cohort study.

SETTING

Medical/surgical intensive care unit (ICU) in a multidisciplinary community hospital.

PATIENTS

All patients admitted to the ICU from January 1, 1987 to March 31, 1991 who both demonstrated clinical evidence of the systemic inflammatory response syndrome and yielded blood cultures positive for a bacterium or fungus (n = 153).

INTERVENTIONS

Random set of procedures normally performed in an ICU setting.

MEASUREMENTS AND MAIN RESULTS

Patient characteristics, including age, blood culture results, comorbid conditions, and severity of illness as estimated by the Acute Physiology Score of the Acute Physiology and Chronic Health Evaluation II prognostic system were recorded. Follow-up evaluation utilizing the National Death Index provided survival outcome for all patients 1 yr after hospital discharge. The mortality rate at hospital discharge was 51.0%, and mortality rates at 1 month, 6 months, and 1 yr after admission date were 40.5%, 64.7%, and 71.9%, respectively. A total of 33 patients survived beyond the period of observation. The analyses demonstrated the following findings: a) the survival rate was negatively correlated with the Acute Physiology Score up to 1 month after hospital admission date, but uncorrelated thereafter; b) fungal infections, such as Candida, had the shortest survival prospects of any blood-borne infection; and c) both malignancy and human immunodeficiency virus infection contributed to poorer outcomes, but differed in their patterns of long-term survival.

CONCLUSIONS

The most critical period for surveillance of bacteremic patients was in months 2 through 6 after discharge, during which time, the percentage of patients surviving decreased dramatically. The degree of physiologic derangement, as measured by the Acute Physiology Score, was a useful measure of prognosis within the first month after the score was assessed at ICU admission. However, beyond this period, prognostic utility decreased significantly. Healthcare providers should use caution concerning the expected survival of hospitalized patients with human immunodeficiency virus, based on experience with distinct conditions, such as malignancies.

Incidence of cerebral hemorrhage after treatment with tissue plasminogen activator or streptokinase following embolic stroke in rabbits [corrected]

We studied thrombolysis in an animal model of embolic stroke to determine the safety of tissue plasminogen activator and streptokinase. We occluded the middle cerebral arteries of 137 rabbits with radiolabeled blood clots and administered tissue plasminogen activator (n = 49), streptokinase (n = 40), or saline (n = 48) at various times after embolization. We assessed the rate of thrombolysis and cerebral hemorrhage 24 hours later. Both drugs were very effective in producing thrombolysis. Compared with saline, streptokinase caused a significant increase in the rate of cerebral hemorrhage (p less than 0.05), but tissue plasminogen activator did not. We conclude that thrombolytic therapy for acute stroke should be safer with tissue plasminogen activator than with streptokinase.

Tissue plasminogen activator-mediated thrombolysis of cerebral emboli and its effect on hemorrhagic infarction in rabbits

Tissue plasminogen activator (tPA) dissolves intravascular thrombus and restores blood flow after thromboembolic vascular occlusion. The utility of this agent for treatment of stroke in humans may be limited by post-reperfusion hemorrhagic complications. We studied tPA-mediated thrombolysis in an animal model of cerebrovascular occlusion in order to determine what factors, if any, predispose tPA-treated animals to suffer hemorrhage. Small blood clot emboli were injected into the internal carotid arteries of rabbits. Angiograms confirmed occlusion of the middle cerebral artery or internal carotid artery in 100% of subjects. tPA or saline was administered as a 30-minute infusion at various times after embolization. Hemorrhage rates were similar in all groups regardless of treatment. tPA increased the prothrombin time and the thrombin time but not the partial thromboplastin time. There was no correlation between these changes in blood coagulation and the finding of cerebral hemorrhage. We observed a significant association between stroke severity and cerebral hemorrhage. We conclude that tPA treatment successfully causes thrombolysis of cerebral emboli without causing an increase in the incidence of cerebral hemorrhage in rabbits.