Characterization of the ovarian cycle in the two-toed sloths (Choloepus didactylus): an innovative, reliable, and noninvasive method using fecal hormone analyses

Little is known about reproductive physiology in the two-toed sloth (Choloepus didactylus). Therefore, the aim of this study was to obtain detailed information about the ovarian cycle. Measurements of reliable gonadal steroids in the feces of this species were undertaken. For this purpose, fecal samples were collected one to three times per week from nonpregnant captive females (n = 2) over a 16-month period. Before assay analysis, the fecal samples were extracted with methanol. Radioimmunoassays and enzyme immunoassays for fecal progesterone, estradiol-17β, pregnanediol-glucuronide (PdG), and estrone sulfate were tested for their ability to detect the ovarian activity. Using the lowest and highest progesterone values, the ovarian cycle length was comparatively analyzed. The ovarian cycle (n = 26) averaged between 31.4 ± 9.1 days (lowest progesterone) and 32.5 ± 7.5 days (highest progesterone) throughout the whole year. The length of the follicular phase, as indicated by low progesterone levels, was 18.1 ± 4.4 days (range 12-25 days), and the length of the luteal phase, as characterized by elevated progesterone levels, was 13.2 ± 1.8 days (range 11-16 days). In contrast, estradiol-17β and estrone sulfate were not suitable to detect the cycle due to irregular collection intervals. Fecal progesterone and PdG, as well as estradiol-17β and estrone sulfate, significantly correlated (r = 0.621, P < 0.01 and r = 0.606, P < 0.01). PdG concentrations (dilution factor (DF) 1:40) were considerably higher than progesterone concentrations (DF 1:10), PdG amounted in the range of 1326.7 ± 320.2 ng/g wet feces (animal S1) and 1373.8 ± 468.3 ng/g wet feces (animal S2) compared with progesterone concentrations in the range of 98.0 ± 17.0 ng/g (S1) and 105.9 ± 30.0 ng/g (S2). The estrone sulfate levels (DF 1:2) were similar to estradiol-17β (DF 1:22). The mean fecal estradiol-17β concentrations were 6.7 ± 0.9 ng/g for animal S1 and 7.5 ± 1.6 ng/g for animal S2. In conclusion, the ovarian activity of the two-toed sloth was studied using the noninvasive method by means of the fecal steroid monitoring. Progesterone was the most reliable fecal steroid hormone to determine the duration of the ovarian cycle independent of the weekly defecation rate. The course of progesterone concentrations resulted in a cycle length of 4-5 weeks length in the two-toed sloth. Thus, the reproductive activity of the two-toed sloth does not show any seasonality like the three-toed sloth.

Delaunay triangulation-based pit density estimation for the classification of polyps in high-magnification chromo-colonoscopy

In this work we propose a method to extract shape-based features from endoscopic images for an automated classification of colonic polyps. This method is based on the density of pits as used in the pit pattern classification scheme which is commonly used for the classification of colonic polyps. For the detection of pits we employ a noise-robust variant of the LBP operator. To be able to be robust against local texture variations we extend this operator by an adaptive thresholding. Based on the detected pit candidates we compute a Delaunay triangulation and use the edge lengths of the resulting triangles to construct histograms. These are then used in conjunction with the k-NN classifier to classify images. We show that, compared to a previously developed method, we are not only able to almost always get higher classification results in our application scenario, but that the proposed method is also able to significantly outperform the previously developed method in terms of the computational demand.

Endoscopic image analysis in semantic space

A novel approach to the design of a semantic, low-dimensional, encoding for endoscopic imagery is proposed. This encoding is based on recent advances in scene recognition, where semantic modeling of image content has gained considerable attention over the last decade. While the semantics of scenes are mainly comprised of environmental concepts such as vegetation, mountains or sky, the semantics of endoscopic imagery are medically relevant visual elements, such as polyps, special surface patterns, or vascular structures. The proposed semantic encoding differs from the representations commonly used in endoscopic image analysis (for medical decision support) in that it establishes a semantic space, where each coordinate axis has a clear human interpretation. It is also shown to establish a connection to Riemannian geometry, which enables principled solutions to a number of problems that arise in both physician training and clinical practice. This connection is exploited by leveraging results from information geometry to solve problems such as (1) recognition of important semantic concepts, (2) semantically-focused image browsing, and (3) estimation of the average-case semantic encoding for a collection of images that share a medically relevant visual detail. The approach can provide physicians with an easily interpretable, semantic encoding of visual content, upon which further decisions, or operations, can be naturally carried out. This is contrary to the prevalent practice in endoscopic image analysis for medical decision support, where image content is primarily captured by discriminative, high-dimensional, appearance features, which possess discriminative power but lack human interpretability.

[Highlights in gastroenterology 2011]

«Gastro-Highlights», an annual symposium dedicated to continuing education, took place at the University Hospital Zürich for the sixteenth time this autumn. In this well-attended event, major new findings in the fields of gastroenterology and hepatology that were published in the past year or recently presented at the «Digestive Disease Week (DDW)» were summarized for practising gastroenterologists and internists.

[Highlights in gastroenterology 2010]

This summer saw the fifteenth edition of «Gastro-Highlights», a well-attended symposium dedicated to continuing education that takes place each year at the University Hospital in Zurich. Major new findings in the fields of gastroenterology and hepatology that were achieved in the past year and were recently presented at the «Digestive Disease Week (DDW)» were summarized here for practising gastroenterologists and internists.

[Conventional colonoscopy]

In the last 40 years colonoscopy has been the gold standard in diagnosis of conditions affecting the large intestine. We see its main disadvantages in the necessity for intestinal preparation and in the pain not infrequently experienced by patients who are not sedated. Widespread use of sedation has made it possible to improve patient acceptance in recent years. Complications of colonoscopy are rare, and even the removal of large polyps is regarded as a safe procedure. One of the main problems of colonoscopy is that a large number of far from trivial polyps--up to 20% in the literature--are overlooked. New developments, such as higher resolution videochips and chromoendoscopy, lead to a better diagnostic yield, especially of flat lesions. The rapidly developing sector of interventional colonoscopy in particular will ensure that colonoscopy continues to have an important place in the management of illnesses affecting the large intestine.

Successful antibiotic treatment of Helicobacter pylori negative gastric mucosa associated lymphoid tissue lymphomas

BACKGROUND AND AIMS

The role of antibiotic treatment in early stage gastric mucosa associated lymphoid tissue (MALT) lymphoma not associated with Helicobacter pylori infection has not been investigated.

PATIENTS AND METHODS

Six patients with localised gastric MALT lymphoma underwent antibiotic treatment with clarithromycin, metronidazole, and pantoprazole. Staging, including endosonography plus gastroscopy, computed tomography of the thorax and abdomen, colonoscopy, magnetic resonance imaging of the salivary glands, and bone marrow biopsy were performed to rule out distant spread of the disease. In addition, MALT specific genetic changes, including reverse transcriptase-polymerase chain reaction for t(11;18)(q21;q21), were tested in all patients. H pylori infection was ruled out by histology, urease breath test, serology, and stool antigen testing.

RESULTS

All six patients had MALT lymphoma restricted to the stomach, and no evidence of infection with H pylori was found. Only one patient tested positive for t(11;18)(q21;q21) while the remaining five displayed no genetic aberrations. Following antibiotic treatment, endoscopic controls were performed every three months. Five patients responded with lymphoma regression between three and nine months following antibiotic treatment (one partial remission and four complete responses). One patient had stable disease for 12 months and was then referred for chemotherapy.

CONCLUSIONS

Patients with early stage gastric MALT lymphoma negative for H pylori might still benefit from antibiotic treatment as the sole treatment modality.

Diagnostic endoscopic retrograde cholangiopancreatography

Although diagnostic endoscopic retrograde cholangiopancreatography (ERCP) has been replaced in many fields by magnetic resonance cholangiopancreatography (MRCP), considerable amounts of research are still ongoing. Major fields of interest include ways of reducing the incidence of post-ERCP pancreatitis, new ways of improving the yield of tissue sampling, and the diagnosis of sphincter of Oddi dysfunction. In addition, there are new data comparing the diagnostic accuracy of ERCP with that of MRCP and endoscopic ultrasonography.

A rare cause of anemia due to intestinal tuberculosis in a renal transplant recipient

A renal transplant recipient with stable allograft function presented with massive hemorrhagic diarrhea and severe anemia. No microbial infection could be found in stool cultures. Early colonoscopy showed severe colitis with ulceration. Histological samples confirmed granulomatous inflammation with acid-resistant Ziehl-Neelson-positive microorganisms of mycobacterial type. Polymerase chain reaction (PCR) analysis of native mucosal biopsies specified the infectious organism as Mycobacterium tuberculosis complex. The patient responded well to antimycobacterial therapy and was still asymptomatic after 6 months with a stable graft function. Our case shows that tuberculosis can be a severe clinical problem in transplant recipients. Most of the patients with intestinal tuberculosis, reported to literature, were diagnosed post mortem or after explorative laparotomy and bowel resection. Thus, intestinal tuberculosis should be considered when a transplant recipient shows abdominal symptoms with no clear evidence of another infection. Proper diagnosis and treatment resulted in a beneficial outcome in our patient.

Giant benign cystic mesothelioma: a case report and review of literature

A 28-year-old man was admitted because of weight loss and a huge abdominal mass. The abdominal cavity was filled by a large number of cysts with a maximum diameter of 10 cm as diagnosed by ultrasound and computed tomography. Laparotomy was performed and a 33 kg cystic tumour originating from the peritoneum was resected en bloc. Histopathological work-up showed multiple cysts covered by cubic or flat mesothelial cells with uniform nuclei. The final diagnosis was benign cystic mesothelioma. Twenty-three months after surgical debulking, a follow-up computed tomography scan showed recurrence of the disease. In this report, we describe the characteristics, aetiology and differential diagnosis of this rare lesion.

Time-dependency of sensory evoked potentials in comatose cardiac arrest survivors

OBJECTIVE

To assess the validity of early sensory evoked potential (SEP) recording for reliable outcome prediction in comatose cardiac arrest survivors within 48 h after restoration of spontaneous circulation (ROSC).

DESIGN AND SETTING

Prospective cohort study in a medical intensive care unit of a university hospital.

PATIENTS

Twenty-five comatose, mechanically ventilated patients following cardiopulmonary resuscitation

MEASUREMENTS AND RESULTS

Median nerve short- and long-latency SEP were recorded 4, 12, 24, and 48 h after ROSC. Cortical N20 peak latency and cervicomedullary conduction time decreased (improved) significantly between 4, 12, and 24 h after resuscitation in 22 of the enrolled patients. There was no further change in short-latency SEP at 48 h. The cortical N70 peak was initially detectable in seven patients. The number of patients with increased N70 peak increased to 11 at 12 h and 14 at 24 h; there was no further change at 48 h. Specificity of the N70 peak latency (critical cutoff 130 ms) increased from 0.43 at 4 h to 1.0 at 24 h after ROSC. Sensitivity decreased from 1.0 at 4 h to 0.83 at 24 h after ROSC.

CONCLUSION

Within 24 h after ROSC there was a significant improvement in SEP. Therefore we recommend allowing a period of at least 24 h after cardiopulmonary resuscitation for obtaining a reliable prognosis based on SEP.

Stage-dependent therapy of rectal carcinoid tumors

Although malignant behavior of rectal carcinoid tumors is rare, the risk of metastases and death does exist. Adaptation of therapy according to the estimated malignancy seems necessary. To develop a stage-dependent therapy, 31 patients with rectal carcinoid tumors measuring 5 to 50 mm in diameter were analyzed retrospectively. Malignancy was estimated according to tumor size, infiltration depth, and histopathology. There were 18 tumors within the mucosa and submucosa (T1), 7 tumors with muscularis propria invasion (T2), and carcinoid tumor penetrating the full rectal wall (T3) or spreading to surrounding tissue (T4) in 6 patients. Altogether 20 patients (65%) were treated with a minimally invasive intervention: endoscopic polypectomy (EP) in 12 and transanal excision (TE) in 8 patients. In 11 patients (35%) aggressive surgical procedures--anterior resection (AR) in 4 and abdominoperineal resection (APR) in 7--were performed. After a mean +/- SD follow-up of 86.0 +/- 61.3 months, tumor recurrence was not seen in any of the 20 patients with minimally invasive treatment, and all were still alive. No severe complications associated with surgical procedures were detected. In contrast, 5 of the 10 patients with advanced tumor stage died from their disease despite aggressive surgery (AR, APR). In conclusion, depending on tumor stage, treatment of rectal carcinoids includes EP, TE, or extended resection. Minimally invasive techniques are safe treatments for small to medium-size T1/T2 rectal carcinoids. Extended surgery cannot improve the overall survival of those with advanced tumors (T3/T4, N1, M1) but can be beneficial for preventing local complications.