Sigmoid Part Research Articles

Epiploic Appendigitis – Presenting as Acute Abdomen: Diagnostic Pitfalls and Clinical Insights

Introduction: Epiploic appendigitis is a rare, benign, self-limiting inflammatory process of the epiploic appendices. The epiploic appendices are small pouches of the peritoneum filled with fat and situated along the colon, mainly the transverse and sigmoid parts, but are absent in the rectum and have an unknown function. These appendages can become acutely inflamed as a result of torsion or venous thrombosis. Case Report: A young patient came to emergency department of our hospital with complain of pain in abdomen at left lumber region since five days. On Physical examination revealed lump at left lumber region at the site of pain. Further investigated by radiological. Discussion: Epiploic appendigitis is an uncommon condition first described by Lynn et al in 1956 and is one of the rare causes of acute abdomen secondary to the inflammation and necrosis of small finger like projections along the colon. These appendages refer to adipose structures that rise in the surface of the colon and project into the abdominal cavity. Conclusion: Given the rarity of this condition, its elusive nature and tendency to mimic acute appendicitis, diverticulitis or cholecystitis, which all may require surgical intervention, it is increasingly apparent that we should educate medical professionals on this important differential diagnosis, as early and accurate diagnosis can prevent unnecessary invasive treatments and misdiagnosis.

Effective management of ulcerative colitis with Udumbara kwatha and Udumbara kwatha basti: A single case report

Ulcerative Colitis (UC) is an idiopathic, chronic inflammatory disorder of the colonic mucosa with remitting and relapsing pattern that usually involves the rectum and extends proximally to involve the sigmoid part of the colon (proctosigmoiditis) or whole colon (pancolitis). The cardinal symptoms are rectal bleeding with the passage of mucus and bloody diarrhea. In modern medical science, there is no permanent curative and safe treatment for this disease. A 32-year-old male, advocate by profession, diagnosed with UC for the past six years, presented to the hospital with complaints of frequent stools mixed with blood and mucous associated with abdominal pain. The condition was managed with Udumbara kwatha basti (~therapeutic enema with Udumbara decoction) and other Shamana aushadha (~palliative medicines). After one month of management, the stool frequency was reduced, and after a follow-up of one-year, normal consistency of stools was attained. This case report illustrates the significance of ayurvedic treatment modalities in the management of UC, generating hypothesis for further research.

Pemodelan Deteksi Black Campaign Sumber Media Berita Online Menggunakan Long Short Term Memory

Developed a black campaign detection model to obtain an accuracy level of classifying online news using the LSTM (Long Short Term Memory) algorithm.Aggregation of neural networks in sheet layers to iteratively learn from the data collected by emulating the workings of the like human brain does the job so computers can be trained in abstraction with the problem is not well defined. The LSTM (Long Short Term Memory) text-processing learning method is used for text classification through the stages of data collection, data preprocessing, word representation, classification, and evaluation. LSTM adds capability and erases information from the cell state. Gates consist of a sigmoid part of layers and multiplication operation. Hyperparameter value is determined from Vocab_size, Embedding_dim Activation Function, Number of epoc, and Learning rate. Evaluation of the showing of the data training performance on data testing shows that the value of LSTM is in identifying online news MAPE 8%. The RMSE evaluation shows that the parameter Number of epochs has a high value of 0.053728.

The Outcome of Resection and Primary Anastomosis (With On-table Lavage) Management of Acute Sigmoid Volvulus, A Developing Country Experience

Background: Acute sigmoid volvulus is the third most common cause of large bowel obstruction. It occurs when the sigmoid part of the colon twists around its blood supply. Methodology: This is a retrospective cross-sectional study detailing the outcome of 15 patients with acute sigmoid volvulus who underwent resection of the affected part of the colon and primary resection with on-table lavage in Khartoum, Sudan in the period from January 2019 to January 2021. All 15 patients were recruited on the basis of their fitting status for surgery and their consent to the procedure. All patients have been followed-up for a period of 2 months post-operatively with no loss to follow-up. Results: The outcome for all 15 patients was excellent with no complications. All patients have been followed up for a period of 2 months following their surgeries. There was no loss to follow-up among them and all of them have attended their post-operative follow up clinics. There were no reported wound problems of dehiscence and infection, anastomotic leakages or the need for revision surgery. Patients have a mean age of 46 years. One of the participants was a Jehovah’s witness; therefore, a cautious approach was implemented during surgery. Another one of the participants were suffering from left hip fracture when he underwent surgery, requiring a high level of care during his pre, peri as well as post-operative care. Conclusion and Recommendation: The outcome for resection and primary anastomosis with on-table lavage can be excellent with no complications. One limitation of this study, as this is not a comparative study, is that no comparison between the outcome of such procedure with the Hartmann’s procedure approach to managing such a condition. We recommend large-scale comparison between the outcome for both approaches to managing acute sigmoid volvulus.

The absence of Syndecan‐1 leads to more inflammation in the mouse model of inflammatory bowel disease (IBD)

Introduction Inflammation of the gut lining constitute the basis for IBD pathogenesis, a disease with multifactorial etiology. In addition, there is suggestive evidence that the interaction of CD147, β1 integrin and Syndecan-1 (Sdc-1) could control the inflammation process and impact healing. Aim The aim of this work is to look at the pathogenesis of IBD in Sdc-1 null mice as compared to control (BALB/C). Our hypothesis is that in the absence of Sdc-1 a more severe inflammation will be observed. Method In this study, 32 male (16 BALB/c and 16 Sdc-1 null) mice, 8-10 weeks old were used after the Institutional Animal Care and Use Committee approval. They were divided equally into 4 groups. Half of the mice (8 BALB/C and 8 Sdc-1 null were given 1 cycle of 2.5 % DSS in drinking water for 1 week while the rest were given the 1st cycle of DSS then 2 weeks normal drinking water followed by a second cycle of 7 days of 2.5% DSS in drinking water. The animals were monitored and weighed daily/ observed clinically for body weight, stool consistency, gross bleeding scores as well as fecal occult blood. The animals were sacrificed at 1 week, 3 weeks and 4 weeks post DSS and 8 animals (4 BALB/C and 4 Sdc-1 null) were supposed to be sacrificed 6 weeks post DSS yet at week 5 all the Sdc-1null mice died while the BALB/C mice are still alive. The lengths of the colons were measured and the sigmoid part was used for histological comparison, at this stage, between the two strains. Results Preliminary data showed that in Sdc-1 null mice there was more weight loss, earlier rectal bleeding and death of animals compared to BALB/C. Moreover, the histological alterations in Sdc-1 null were more sever with more dissemination of the inflammation and cryptitis as well erosion of the intestinal lining epithelium compared to BALB/C mice. Conclusion Sdc-1null mice are more sensitive to IBD induction compared to the control BALB/C. The loss of Sdc-1 makes the inflammation more acute and lethal. More dose effect studies and characterizations are ongoing, hoping it will lead to a novel therapeutic approach for IBD treatment.

Endoscopic Endonasal Approach to the Ventral-Medial Portion of Posterior Paramedian Skull Base: A Morphometric Perspective of Surgical and Radiologic Anatomy

This study aims to provide morphometric analysis of endoscopic endonasal approach (EEA) to the ventral-medial portion of posterior paramedian skull base. Furthermore, it aims to investigate the surgical exposure obtained through EEA with and without eustachian tube (ET) removal, emphasizing the role of contralateral nostril (CN) access. Five fresh adult head specimens were prepared for dissection. A predissection and a postdissection computed tomography study was performed. A surgically oriented classification into 4 regions was used: 1) tubercular region; 2) occipital condyle region; 3) parapharyngeal space (PPhS) region; and 4) jugular foramen (JF) region. The Student t-test was used to compare angulations and measures of EEA with access from the ipsilateral and CN, respectively, with and without ET removal. EEA to the ventral-medial portion of posterior paramedian skull base encompasses 2 medial trajectories (transtubercular and transcondylar) and 2 lateral pathways to the PPhS and JF. The CN access, without removal of the ET, allows a complete exposure of the petrous and intrajugular portion of the JF and superior PPhS without exposition of the parapharyngeal segment of internal carotid artery. The ipsilateral nostril approach with ET removal allows to obtain a wider exposure, reaching the medial sigmoid part of the JF. No significant differences exist in regard to transtubercular and transcondylar approaches. This study suggests that EEA to posterior paramedian skull base allows the realization of a corridor directed to the jugular tubercle, occipital condyle, medial PPhS, and ventral-medial JF. The CN approach with ET preservation can expose the petrous and intrajugular parts of the JF and PPhS. Case series are needed to demonstrate benefits and drawbacks of these approaches.

Involvement of Recovery Processes in the Effects of Radioprotectors at the Cellular and Organismal Levels

A correlation between the effectiveness of the radioprotective action of cysteamine with the radiosensitivity of cells and their ability to recover from radiation damage was demonstrated for diploid yeast cells of S. cerevisiae. To demonstrate the involvement of the recovery processes in the mechanism for radioprotective action of the T1023 compound in animals, data on the survival of clonogenic bone marrow cells of mice exposed to ionizing radiation are presented. It is shown that the radioprotective effect of this compound can be realized not only at the physicochemical stage of formation of radiation damage due to a decrease in the oxygen content in tissues but also due to the post-radiation cell recovery at the biochemical stage. This is confirmed by the presence of the sigmoid part of the dose-response curve in the region of low doses of ionizing radiation.

Expect the Unexpected in a Colonoscopy: A Case of Colonic Endometriosis

Endometriosis is defined by the presence and the proliferation of endometrial tissue outside the uterus. Estimate prevalence is nearly 10-15% in women of reproductive age group. Symptoms vary according to location where endometrial tissue is implanted. Intestinal endometriosis can occur in up to 37% of all cases of endometriosis, mainly affecting recto sigmoid part of colon. Our patient is a 32-year-old female with past history of infantile cerebral palsy, seizure disorder and chronic constipation presented to our gastroenterology clinic with abdominal pain. Symptoms have been waxing and waning for years, described as diffuse abdominal pain, cramping in nature and associated with severe constipation. Patient denied any other symptoms, including hematemesis, hematochezia or melena. Patient reported family history of unknown cancer. Physical exam was remarkable for scars from previous cesarean sections. No abdominal tenderness, guarding or rigidity was appreciated. Basic laboratory testing was unremarkable. Colonoscopy visualized a 1 cm sessile polyp (figure 1) in descending colon that was snared, cauterized and retrieved (figure 2). Histology of the polyp revealed benign endometrial glands and stroma, consistent with diagnosis of endometriosis. Patient was started on oral contraceptive medication with dramatic improvement of abdominal pain before patient preferentially stopped it due to weight gain. A follow up colonoscopy for recurrent abdominal pain visualized diminutive polyp in the sigmoid colon that was removed by snare polypectomy. Pathology was consistent with hyperplastic polyp. On outpatient follow up, patient denied any more symptoms of abdominal pain. Endometriosis is a hormone responsive pathological implanting of endometrial tissue outside the uterus. Symptoms of endometriosis vary. Intestinal endometriosis usually manifests as alteration in bowel habits, rectal bleeding and dyschezia. Our patient presented with non-specific abdominal pain that initially responded with oral contraceptive medication. Although patient with diagnosis of endometriosis usually tend to be infertile unless treated, our patient had delivered more than once before she was diagnosed with endometriosis. We present this case so we as gastroenterologist and internists would have low index of suspecion of this rare pathology.Figure: Colonoscopy visualized a 1 cm sessile polyp in the descending colon.Figure: Appearance of bleeding polyp after it was snared and cautarized.

Large Bowel Perforation in an Acute Inguinal Hernia Resulting from Blunt Abdominal Trauma

Traumatic abdominal hernia is a very rare condition with less than 70 reported cases, in spite of an increase in the incidence of trauma. Often, the trauma to the abdomen results in damage to solid or to the hollow viscus. The trauma causing TAWH can be due to high energy or low energy impact. We report a very rare condition wherein there was a blunt injury to the abdomen that resulted in the acute inguinal hernia with perforated sigmoid colon, small bowel and part of urinary bladder being its contents. To our knowledge, this is the first such case being documented by us.

An unusual complication of renal transplantation: a fistula between the sigmoid colon and the graft

The wide-spreading of organ transplantation [1–3] with consequent immuno-suppressive and steroid therapy [4] has led to an increase of complications of the gastrointestinal tract, with percentages ranging from 8 to 20 % [5–7]. Complications include perforated gastro-duodenal ulcers, cholecystitis, acute pancreatitis, appendicitis, perforated or fistulized diverticulitis, pseudo-membranous colitis, and perianal fistulas [5, 6]. Diverticulitis is the most common cause of colonic perforation in the renal-transplanted population. These complications have high morbidity and mortality rates in immuno-suppressed patients [5]. Immunosuppression and steroid therapy reduce the inflammatory response [7], often masking the symptoms and giving ambiguous clinical presentations that can result in diagnostic delay. We describe the case of a fistula between the sigmoid colon and the transplanted kidney due to diverticular disease and chronic inflammation after repeated surgeries for a stricture of the anastomosis between the bladder and the ureter. The fistula appeared approximately 2 years after the immuno-suppressive therapy was stopped. The patient was treated with an en-bloc resection of the graft, the sigmoid colon and part of the bladder. To our knowledge this is the first case described in the literature with such a complication.

PERCEPTRON NETWORK FOR RBF LOVERS

There are two basic types of artificial neural networks: Multi-Layer Perceptron (MLP) and Radial Basis Function network (RBF). The first type (MLP) consists of one type of neuron, which can be decomposed into a linear and sigmoid part. The second type (RBF) consists of two types of neurons: radial and linear ones. The radial basis function is analyzed and then used for decomposition of RBF network. The resulting Perceptron Radial Basis Function Network (PRBF) consists of two types of neurons: linear and extended sigmoid ones. Any RBF network can be directly converted to a four-layer PRBF network while any MLP network with three layers can be approximated by a five-layer PRBF network. The new PRBF network is then a generalization of MLP and RBF network abilities. Learning strategies are also discussed. The new type of PRBF network and its learning via repeated local optimization is demonstrated on a numerical example together with RBF and MLP for comparison. This paper is organized as follows: Basic properties of MLP and RBF neurons are summarized in the first two chapters. The third chapter includes novel relationship between sigmoidal and radial functions, which is useful for RBF decomposition and generalization. Description of new PRBF network, together with its properties, is subject of the fourth chapter. Numerical experiments with a PRBF and their requests are given in the last chapters.

Intestinal ischemia measured by intraluminal microdialysis

Objective. To evaluate the possibility of detecting intestinal ischemia by intraluminal microdialysis and comparing the ileum and colon. Methods. The studies were performed on male Sprague-Dawley rats. In the first part of the study, microdialysis catheters were placed in the sigmoid part of the colon and in the subcutaneous adipose tissue. In the second part of the study, microdialysis catheters were placed in the lumen of the ileum and the colon. The infrarenal aorta was clamped proximal to the cranial mesenteric artery. Microdialysate levels of glucose, lactate, pyruvate and glycerol were measured. Intestinal specimens were removed at the end of the ischemic period for microscopic evaluation. Results. Intraluminal microdialysis could detect early signs of ischemic injury in the ileum, as well as in the colon, with a marked increase of lactate, lactate/pyruvate ratio and glycerol. The increased levels of intraluminal glycerol showed a positive correlation to prolonged ischemia and to higher degrees of intestinal damage. Conclusion. Intraluminal measurement of glycerol is a good marker for intestinal ischemia. Intraluminal microdialysis in the colon is easily accessible through the rectum, and may prove to be a valuable clinical tool for diagnosing intestinal ischemia.

Prostaglandin E2-induced colonic secretion in patients with and without colorectal neoplasia

BackgroundThe pathogenesis for colorectal cancer remains unresolved. A growing body of evidence suggests a direct correlation between cyclooxygenase enzyme expression, prostaglandin E2 metabolism and neoplastic development. Thus further understanding of the regulation of epithelial functions by prostaglandin E2 is needed. We hypothesized that patients with colonic neoplasia have altered colonic epithelial ion transport and express functionally different prostanoid receptor levels in this respect.MethodsPatients referred for colonoscopy were included and grouped into patients with and without colorectal neoplasia. Patients without endoscopic findings of neoplasia served as controls. Biopsy specimens were obtained from normally appearing mucosa in the sigmoid part of colon. Biopsies were mounted in miniaturized modified Ussing air-suction chambers. Indomethacin (10 μM), various stimulators and inhibitors of prostanoid receptors and ion transport were subsequently added to the chamber solutions. Electrogenic ion transport parameters (short circuit current and slope conductance) were recorded. Tissue pathology and tissue damage before and after experiments was assessed by histology.ResultsBaseline short circuit current and slope conductance did not differ between the two groups. Patients with neoplasia were significantly more sensitive to indomethacin with a decrease in short circuit current of 15.1 ± 2.6 μA·cm-2 compared to controls, who showed a decrease of 10.5 ± 2.1 μA·cm-2 (p = 0.027). Stimulation or inhibition with theophylline, ouabain, bumetanide, forskolin or the EP receptor agonists prostaglandin E2, butaprost, sulprostone and prostaglandin E1 (OH) did not differ significantly between the two groups. Histology was with normal findings in both groups.ConclusionsEpithelial electrogenic transport is more sensitive to indomethacin in normal colonic mucosa from patients with previous or present colorectal neoplasia compared to colonic mucosa from control patients. Stimulated epithelial electrogenic transport through individual prostanoid subtype receptors EP1, EP2, EP3, and EP4 is not significantly different between neoplasia diseased patients and controls. This indicates that increased indomethacin-sensitive mechanisms in colonic mucosa from neoplasia diseased patients are not related to differences in functional expression of EP receptor subtypes.

Colonic epithelial ion transport is not affected in patients with diverticulosis

BackgroundColonic diverticular disease is a bothersome condition with an unresolved pathogenesis. It is unknown whether a neuroepithelial dysfunction is present. The aim of the study was two-fold; (1) to investigate colonic epithelial ion transport in patients with diverticulosis and (2) to adapt a miniaturized Modified Ussing Air-Suction (MUAS) chamber for colonic endoscopic biopsies.MethodsBiopsies were obtained from the sigmoid part of the colon. 86 patients were included. All patients were referred for colonoscopy on suspicion of neoplasia and they were without pathological findings at colonoscopy (controls) except for diverticulosis in 22 (D-patients). Biopsies were mounted in MUAS chambers with an exposed area of 5 mm2. Electrical responses to various stimulators and inhibitors of ion transport were investigated together with histological examination. The MUAS chamber was easy to use and reproducible data were obtained.ResultsMedian basal short circuit current (SCC) was 43.8 μA·cm-2 (0.8 – 199) for controls and 59.3 μA·cm-2 (3.0 – 177.2) for D-patients. Slope conductance was 77.0 mS·cm-2 (18.6 – 204.0) equal to 13 Ω·cm2 for controls and 96.6 mS·cm-2 (8.4 – 191.4) equal to 10.3 Ω·cm2 for D-patients. Stimulation with serotonin, theophylline, forskolin and carbachol induced increases in SCC in a range of 4.9 – 18.6 μA·cm-2, while inhibition with indomethacin, bumetanide, ouabain and amiloride decreased SCC in a range of 6.5 – 27.4 μA·cm-2, and all with no significant differences between controls and D-patients. Histological examinations showed intact epithelium and lamina propria before and after mounting for both types of patients.ConclusionWe conclude that epithelial ion transport is not significantly altered in patients with diverticulosis and that the MUAS chamber can be adapted for studies of human colonic endoscopic biopsies.

Avantages de l’abord rétro-labyrinthique pour l’exérèse des méningiomes insérés au pourtour du coude du sinus latéral

To describe the retrolabyrinthine approach for the resection of 9 meningiomas inserted around the lateral sinus between the transverse and sigmoid parts, to discuss the value of this approach compared to the retrosigmoid approach for resection of meningioma in this localization and to review the literature. Retrospective study. Between 1988 and 2002, 9 patients (8 female, mean age 50 years) underwent surgery via the retrolabyrinthine approach for resection of meningiomas inserted around the lateral sinus between the transverse and sigmoid parts. Resection was total (8 Simpson I and 1 Simpson II) in all patients. In the early postoperative course, one patient was treated for meningitidis with an LCR leak and one patient present a temporary paresis of the vagus nerve. Mean follow-up was 5 years (6 months-10 years). All patients continued their pre-treatment occupation after surgery. No recurrence was observed. Two approaches can be used for resection of meningiomas in this localization. The retrosigmoid approach is a common neurosurgical approach exposure of the cerobellopontine angle. It is practised by most neurosurgeons. Via this approach, the cerebellar lobe must be pushed back so the arteries feeding the tumor are in the operative field at the end of the procedure. For numerous authors the operative field is too narrow. On the other hand, the retrolabyrinthine approach described in 1972 by Hitselberger and Pulec allows exposure of feeding arteries during the first steps of operation, an easier resection of meningioma insertion and better control of the lateral sinus. This approach can be enlarged to the retrosigmoid or the subtemporal anatomic region.

A method for pharmacokinetic modelling of dynamic contrast enhanced MRI studies of rapidly enhancing lesions acquired in a clinical setting

Abnormal microcirculation is a feature of many neoplastic and non-neoplastic diseases. Physiological variables that characterize tissue microcirculation (capillary permeability and the volume of the extravascular extracellular fluid) are altered in pathological states. Pharmacokinetic analysis of dynamic contrast enhanced MRI (DCE-MRI) has found a widespread use in the assessment of abnormal microcirculation due to the direct link between the contrast agent kinetics and underlying microcirculatory properties. A representation of temporal variation of contrast agent concentration in blood plasma (Cp(t)) is central to this analysis. In clinical applications of DCE-MRI, signal intensity curves derived from rapidly enhancing lesions often display a sigmoid shape during the initial phase of contrast uptake and rapid arrival at the equilibrium phase. In this work, the features of two principal methods for pharmacokinetic analysis of DCE-MRI which allow for theoretical representation of Cp(t) are examined and combined to improve analysis of this particular class of DCE-MRI curves. The proposed method allows the representation of the initial sigmoid part of the enhancement profiles whilst retaining a realistic representation of Cp(t) based on previously published measurements obtained in healthy volunteers. The results of the computer simulations indicate that in rapidly enhancing lesions, with the transfer constant Ktrans greater than 0.1 min−1, the DCE-MRI acquisition can be restricted to 5 min post-injection and a mono-exponential representation of Cp(t) decay is sufficient. Furthermore, non-ideal bolus delivery can be represented as a short constant rate infusion when the tissue under investigation exhibits a sigmoid pattern of contrast uptake.

Vulnerability of newly settled plaice ( Pleuronectes platessa L.) to predation: effects of habitat structure and predator functional response

Plaice ( Pleuronectes platessa) nursery grounds on the Swedish west coast have been subject to increasing cover of annual green macroalgae during recent years, with growth of algae starting at the time of plaice settlement in April to May. A laboratory experiment was performed to investigate how the vulnerability to predation of metamorphosing plaice was affected by the presence of filamentous algae. Predation by shrimps ( Crangon crangon) on settling plaice larvae was higher on sand than among algae, whereas predation by crabs ( Carcinus maenas) was unaffected by habitat type, suggesting a lower overall mortality of plaice in the vegetated habitat. When predators and prey were presented with a combination of the two habitats, predation by shrimps was as high as that in the sand treatment alone, whereas predation by crabs was lower than that in the two treatments with one habitat. Based on these results, an additional experiment was performed, investigating the functional response of shrimps to six densities of juvenile plaice in a sand habitat with alternative prey present. The proportional mortality of juvenile plaice (12–16 mm total length (TL)) was density-dependent and was best described by a type III (sigmoid) functional response of the predatory shrimps. The results suggested that the combined predation pressure from shrimps and crabs was lower among algae than on sand, but settling plaice and predatory shrimps chose the sand habitat. Plaice densities in the sigmoid part of the obtained functional response curve represented normal to high field densities of plaice on the Swedish west coast, suggesting that shrimp predation could have a stabilising effect on plaice recruitment. The formation of macroalgae mats could therefore lead to a concentration of plaice juveniles in the remaining sand habitat and increased mortality through density-dependent predation by shrimps.

Deaths and tumours among workers grinding stainless steel: a follow up.

OBJECTIVE: To study cause specific mortality and cancer morbidity in workers exposed to the dust of grinding materials, grinding agents, and stainless steel, especially with regard to a possibly increased...

The jugular foramen: microsurgical anatomy and operative approaches.

The jugular foramen, based on these studies of microsurgical anatomy, is divided into three compartments: two venous and a neural or intrajugular compartment. The venous compartments consist of a larger posterolateral venous channel, the sigmoid part, which receives the flow of the sigmoid sinus, and a smaller anteromedial venous channel, the petrosal part, which receives the drainage of the inferior petrosal sinus. The petrosal part forms a characteristic venous confluens by also receiving tributaries from the hypoglossal canal, petroclival fissure, and vertebral venous plexus. The petrosal part empties into the sigmoid part through an opening in the medial wall of the jugular bulb between the glossopharyngeal nerve anteriorly and the vagus and accessory nerves posteriorly. The intrajugular or neural part, through which the glossopharyngeal, vagus, and accessory nerves course, is located between the sigmoid and petrosal parts at the site of the intrajugular processes of the temporal and occipital bones, which are joined by a fibrous or osseous bridge. The glossopharyngeal, vagus, and accessory nerves penetrate the dura on the medial margin of the intrajugular process of the temporal bone to reach the medial wall of the internal jugular vein. The operative approaches, which access the foramen and adjacent areas and are demonstrated in a stepwise manner, are the postauricular transtemporal, retrosigmoid, extreme lateral transcondylar, and preauricular subtemporal-infratemporal approaches.

Glycosphingolipids of Human Large Intestine: Detailed Structural Characterization with Special Reference to Blood Group Compounds and Bacterial Receptor Structures1

Non-acid glycosphingolipid expression was studied in the large intestines from four individuals with the A1Le(a-b+), BLe(a-b+), and OLe(a-b+) blood group phenotypes. In the A1Le(a-b+) case, specimens were taken from the ascending and sigmoid parts of the large intestine in order to compare the expression of glycolipids in the proximal and distal regions of the intestine. In one blood group OLe(a-b+) individual, epithelial cells were isolated from the residual stroma to compare the glycolipid compositions in these two tissue compartments. GlcCer, GalCer, LacCer, Gb3Cer, and Gb4Cer were the major compounds in all three individuals, as shown by mass spectrometry, proton NMR spectroscopy, and degradation studies. The Lea-5 glycolipid was the major complex blood group glycolipid in all individuals, except in the proximal ascending part of the large intestine of the A1Le(a-b+) case, in which the Leb-6 glycolipid was predominant. There were trace amounts of blood group ABH glycolipids, in agreement with the ABO blood group phenotypes of the donors, Lewis antigens with more than six sugar residues in the carbohydrate chain, and blood group X and Y glycolipid antigens. The epithelial cells were dominated by monoglycosylceramides and the Lea-5 glycolipid, while only trace amounts of di-, tri-, and tetraglycosylceramide structures were present. No reactivity was seen in the epithelial cell fraction with Gal alpha 1-4Gal specific Escherichia coli, anti-Pk, or anti-P antibodies, indicating the absence of the glycolipid-borne Gal alpha 1-4Gal sequence in human large intestinal epithelial cells.