Zigzag persistence for coral reef resilience using a stochastic spatial model

A complex interplay between species governs the evolution of spatial patterns in ecology. An open problem in the biological sciences is characterizing spatio-temporal data and understanding how changes at the local scale affect global dynamics/behaviour. Here, we extend a well-studied temporal mathematical model of coral reef dynamics to include stochastic and spatial interactions and generate data to study different ecological scenarios. We present descriptors to characterize patterns in heterogeneous spatio-temporal data surpassing spatially averaged measures. We apply these descriptors to simulated coral data and demonstrate the utility of two topological data analysis techniques-persistent homology and zigzag persistence-for characterizing mechanisms of reef resilience. We show that the introduction of local competition between species leads to the appearance of coral clusters in the reef. We use our analyses to distinguish temporal dynamics stemming from different initial configurations of coral, showing that the neighbourhood composition of coral sites determines their long-term survival. Using zigzag persistence, we determine which spatial configurations protect coral from extinction in different environments. Finally, we apply this toolkit of multi-scale methods to empirical coral reef data, which distinguish spatio-temporal reef dynamics in different locations, and demonstrate the applicability to a range of datasets.

Acute Bleeding from Leiomyoblastoma of the Greater Omentum. A Case Report

Extragastric leiomyoblastomas are extremely rare. This is the sixth reported case of leiomyoblastoma of the greater omentum, and the only one with acute major bleeding which required an emergency operation. Leiomyoblastomas are low-grade malignant tumors, and especially the gastric ones have an excellent prognosis after surgical removal. Extragastric leiomyoblastomas have a higher rate of dissemination. However, none of the previously reported omental leiomyoblastomas showed signs of metastatic spread at the time of operation. The present patient is alive and well 18 months postoperatively.

Non-traumatic perforation of gastric ulcer in a hiatal hernia to the pericardium

A patient with ulcer in a hiatal hernia with perforation to the pericardial sac is reported. The symptoms and signs of non-traumatic perforation from esophagus or stomach to the pericardium or heart are described on the basis of a brief review of the literature. A prominent feature of our patient was long-standing pain in the left shoulder. We suggest that this symptom may be a warning of threatening pericardial perforation.

Vascular reactivity of the preplacental vasculature in Guinea pigs

The functional correlates of structural remodelling of the preplacental arteries are not well known. We examined the responses of these vessels to vasoactive agents in guinea pigs at mid and late gestation, and attempted to relate them to changes in vessel structure. Segments were taken from the arcade artery, a mesometrial artery near its origin, and an artery near the placenta. They were mounted as rings in a myograph and concentration-response curves were obtained for U46619, endothelin-1 and arginine vasopressin. The vessel segments were then examined by histology and immunohistochemistry. Trophoblast was identified as immunopositive for cytokeratin, circular muscle stained positive for muscle actin and smooth muscle actin, and presumed myofibroblasts in the adventitial layer stained positive only for smooth muscle actin. At both gestational ages, arcade and mesometrial arteries had intact vessel walls. Midgestation placental arteries were characterized by partial or complete disruption of the internal elastic lamina and the presence of a large number of myofibroblasts and of periarterial trophoblast. In late pregnancy, the changes were more extensive, with almost complete dedifferentiation of the smooth muscle cells and trophoblast invasion of the adventitial layer. From midgestation to late gestation, the responses of placental arteries to U46619, endothelin-1 and arginine vasopressin, normalized to the response to K(+)depolarization, were significantly reduced. This suggests that the extensive changes in wall structure in late gestation, which accompany trophoblast invasion, modulate the responses of these vessels to vasoconstrictors. However, mesometrial arteries also demonstrated reduced responsiveness to U46619, suggesting the influence of factors other than trophoblast.

Morphological findings and value of placental examination at fetal and perinatal autopsy

The purpose of this study was to report on the morphological findings in placentae from abortions, stillbirths and perinatal deaths, and to assess the value of the results of the placental examinations. The material included 341 placentae and their matched autopsies. Fifty placentae came from abortions induced for medical reasons, 194 from spontaneous abortions, 84 from stillbirths, and 13 from livebirths. Histological slides from all placentae were reviewed and the placental diagnoses were related to the autopsy diagnoses. Frequently observed placental lesions were inflammation of the membranes and/or umbilical cord, placental edema, vascular lesions, single umbilical artery, and degenerative lesions. The placental examination in pregnancies terminating with fetal or perinatal death was of value in half the cases. Some placental lesions provide us with clues when assessing the cause of fetal death, but such lesions are rare. Two important groups of lesions, acute inflammation of the membranes and/or umbilical cord and lesions consistent with uteroplacental vascular insufficiency, seen mainly as infarction and decidual arteriopathy, were observed. Gross examination is informative, though microscopic examination is often necessary.

Basis for decisions on emerging health technology. A Danish feasibility study

The objectives of the feasibility study were to evaluate sources of information for an eventual Danish system for early identification and assessment of emerging health technology, to identify potential users of the system, and to clarify their specific need for information concerning emerging health technology. The methods used were questionnaires to informants within and outside the health services and to decision makers on different levels in the health services, and follow-up telephone interviews. Our study reveals a strong, and to some extent unsatisfied, need among policy makers, planners, and managers in the Danish health services for information concerning emerging health technology. The requested information should in particular concern indication for use, number of patients affected, clinical effectiveness and side effects, running cost, and investments. The time horizon most relevant to the decision makers seems to be only zero to 2 years. Furthermore, we found that numerous sources are available that frequently display information on emerging technology important to the health services. The challenges seem to be to select information of sufficient importance and quality, and to combine information, since very few, if any, single primary sources cover all the requested information. In conclusion, we recommend the establishment of a Danish national system for early identification and assessment of emerging health technology, consisting of a small secretariat that collaborates nationally and internationally, the latter in particular on identification of technology and on development of methods for early assessment.

Transvaginal ultrasound, endometrial cytology sampled by Gynoscann and histology obtained by Uterine Explora Curette compared to the histology of the uterine specimen. A prospective study in pre- and postmenopausal women undergoing elective hysterectomy

BACKGROUND

The purpose of this study was to evaluate the diagnostic value of transvaginal ultrasound measurement of endometrial thickness, cytology obtained by Gynoscann, and histology of the endometrium sampled by Uterine Explora Curette compared with histology of the uterine specimen as the gold standard.

METHODS

Consecutive patients admitted for hysterectomy had transvaginal ultrasound, sampling by Gynoscann, and Uterine Explora Curette done just before surgery, after informed consent.

RESULTS

A total of 181 women entered the study. Sixteen had endometrial cancer, seven had atypical hyperplasia and nine had complex hyperplasia. A total of 168 patients had a transvaginal ultrasound done. At a cutoff limit of 4mm (endometrial thickness of 4mm or less indicating normal endometrium), the sensitivity was 90.3%, the specificity 24.8%, the positive predictive value 21.4% and the negative predictive value 91.9%. One endometrial cancer, one atypical and one complex hyperplasia were missed. The Gynoscann method showed a sensitivity of 62.5%, a specificity of 94.0%, a positive predictive value of 69.0% and a negative predictive value of 92.1%. Two cancers, three atypical and six complex hyperplasia were missed. The Uterine Explora Curette showed a sensitivity of 90.6%, a specificity of 100.0%, a positive predictive value of 100.0% and a negative predictive value of 98.0%. One endometrial cancer and two complex hyperplasia were missed.

CONCLUSION

Transvaginal ultrasound is a reliable method in excluding endometrial pathology. The Uterine Explora Curette was superior to Gynoscann in diagnosing neoplasia of the endometrium. It was found to have the same diagnostic accuracy as conventional dilatation and curettage.

Patterns in expression of insulin-like growth factor-II and of proliferative activity in the normal human first and third trimester placenta demonstrated by non-isotopic in situ hybridization and immunohistochemical staining for MIB-1

The expression of insulin-like growth factor-II (IGF-II) in normal human first and third trimester placental tissue was investigated by non-isotopic in situ hybridization (ISH). This is the first ISH study on IGF-II expression in placenta using an alkaline phosphatase-labelled probe. The expression was correlated with the proliferative activity of the cells using the proliferative marker MIB-1. In first trimester tissue, IGF-II was expressed in the cytotrophoblast, the extravillous trophoblast, the fetal endothelial cells and the mesenchymal fetal cells in the villi. In third trimester tissue, IGF-II expression was found in the amnion, the extravillous trophoblast and the mesenchymal fetal cells especially in the endothelial cells and the outer contractile sheet in the stem villi. In areas with perivillous fibrin deposits, strong expression of IGF-II was found in the cytotrophoblasts invading the fibrin. In first trimester tissue, the proliferative activity of the villous cytotrophoblast correlated well with the degree of IGF-II expression whereas in third trimester tissue, there was a discrepancy between MIB-1 positivity and the IGF-II expression. Expression of IGF-II does not seem to be correlated exclusively to the mitogenic activity of cells.

A stereologic study of postmature placentas fixed by dual perfusion

OBJECTIVE

Placental insufficiency has been considered the cause of increased morbidity in infants delivered postmaturely. Former quantitative studies have indicated a decrease in some placental structures just before term. In this study we describe a method of dual perfusion fixation to provide tissue for stereologic examination. Postmature placentas were examined with this method.

STUDY DESIGN

Eleven postmature placentas and 14 placentas delivered at term were fixed by dual perfusion. The volume and the surface area of villi, the trophoblast volume, and the volume, surface area, and length of villous capillaries were estimated by stereologic examination. The Mann-Whitney test (p < or = 0.05) was used for statistical analysis.

RESULTS

Morphologic features were normal in all placentas. No significant differences were disclosed in the stereologic estimates of placentas delivered at term and postmature placentas.

CONCLUSION

No morphologic or significant quantitative changes were found in postmature placentas.

Partial moles with maze-like vascular anomaly

Two cases of combined maze-like vascular anomaly and partial mole are described. Immunohistochemical staining showed the abnormal vessels to be of endothelial origin. The vessels had been a functioning part of the fetal circulation. Both partial moles were triploid, and both were evacuated in the second trimester.

Mast cells in the placenta. Is there a relation to the development of atopic disease in infants before 18 months of age?

OBJECTIVE

To disclose a relation between the amount of mast cells in placenta and the development of atopic disease in children before 18 months of age.

DESIGN

A prospective, descriptive study.

SETTING

Two obstetric departments at university hospitals.

SUBJECTS

67 pairs of mothers and their newborn infants.

MAIN OUTCOME MEASURES

Family history of atopic disease was taken. The amount of mast cells in placenta was counted. Follow-up questionnaires of the children were evaluated after 18 months.

RESULTS

The follow-up rate was 84%. The number of mast cells in placenta did not differ between atopic and non-atopic children.

CONCLUSION

A new predictor, the amount of mast cells in placenta was evaluated. In this study the amount of mast cells, in placenta was not predictive of the development of atopic disease before 18 months of age.

Preoperative treatment with oestradiol in women scheduled for vaginal operation for genital prolapse. A randomised, double-blind trial

OBJECTIVE

To disclose a clinical and histopathological effect of local low-dose oestradiol treatment on the vagina.

DESIGN

A randomised, double-blind trial.

SETTING

Two gynaecological departments at University Hospitals.

SUBJECTS

Forty-eight postmenopausal women scheduled for surgery because of genital prolapse.

INTERVENTION

25 micrograms oestradiol or placebo, administered as vaginal pessaries daily, 3 weeks prior to surgery.

MAIN OUTCOME MEASURES

Cytological, histological and clinical changes of the vaginal mucosa.

RESULTS

The thickness of the vaginal wall increased as did the oestrogenic index. No clinical effect was seen apart from decreased incidence of recurrent cystitis postoperatively.

CONCLUSIONS

Preoperative oestrogen treatment has been shown to reduce the incidence of recurrent cystitis and may be needed for stimulation of vaginal mucosa; the short-term clinical effect is not convincing, however.

Granulomas of the appendix: is it Crohn's disease?

An epidemiologic study was performed 1) to estimate the occurrence of epithelioid granulomas in the appendix wall among patients in whom an appendectomy had been performed, 2) to identify patients with granulomas in the appendix who had symptoms and history compatible with Crohn's disease, and 3) to estimate the long-term prognosis. Within a 5-year period 6051 patients in Copenhagen County underwent appendectomy. Six patients (0.1%) had epithelioid granulomas of the appendix (0.2 per 10(5) inhabitants per year). Follow-up of the six patients for 9-11 years (median, 9.5 years) showed that all had been free of gastrointestinal symptoms since the operation. Among the 373 patients diagnosed as having Crohn's disease in Copenhagen County between 1962 and 1987, 3 patients had their disease initially confined to the appendix. Follow-up in these patients showed no recurrence within a median of 6 years (range, 4-7 years). Patients with epithelioid granulomas of the appendix have an excellent long-term prognosis, which could be explained by the fact that the condition seems to be unrelated to Crohn's disease.

Long-term survival after resection of ductal carcinoma in the body and tail of pancreas

We report on a 62-year-old male, who had resection of a large ductal carcinoma in the body and tail of the pancreas. Four months later a metastasis was removed from the abdominal scar, and 14 months later another metastasis was removed from the anterior wall of the stomach. Moreover, he had a left mastectomy followed by radiation therapy for a primary ductal carcinoma and a transurethral resection of the prostate because of benign hyperplasia. A minor focus of primary highly differentiated adenocarcinoma was found in the chips. More than 6 years later, the patient is without any signs of recurrences.

Carcinoid tumor of the larynx. A case report with a review of the literature

A carcinoid tumor of the larynx is reported. The tumor was initially interpreted as a poorly differentiated squamous carcinoma and treated with irradiation. One year later a laryngectomy was performed and a carcinoid tumor was found in the resection specimen. The patient died after 2 years with disseminated disease. Carcinoid tumors in the larynx are rare. In the literature 45 cases of laryngeal carcinoid tumors have been reported. The diagnosis of this laryngeal tumor is difficult but important because irradiation is ineffective. Surgical treatment should be performed.

CEA and carbohydrate antigens in normal and neoplastic colon mucosa. An immunohistochemical study

Antibodies raised against tumour-associated antigens have been assessed for tumour selectivity using an indirect immunohistochemical peroxidase staining of formalin-fixed, paraffin-embedded tissue from colon carcinomas, colon polyps and normal mucosa. The following antibodies were used: 1) Unabsorbed polyclonal antibody to carcinoembryonic antigen (poly-CEA). 2) Monoclonal antibodies to CEA (mabs 3851 and 27). 3) Monoclonal antibodies to protein-bound carbohydrates (mabs C 216 and C 242) or to lipid- and protein-bound carbohydrates (C 50 and 19-9). These antibodies had been produced by hybridization of lymphocytes from mice, immunized with colon carcinoma cell lines or colon cancer tissue. All antibodies were used in one concentration only, preselected by initial titration experiments. No antibody was completely tumour-specific, but four antibodies, mabs 3851, 27, C 216 and C 242, showed statistically significant tumour selectivity. Using these antibodies, respectively 19, 19, 19, and 18 of 20 colon cancer were stained compared with 3, 4, 4, and 8 of 15 specimens of colon mucosa from normal controls. An increased frequency of staining was also noted in dysplastic polyps (statistically significant using mabs 3851 and C 216) and in dysplastic mucosa adjacent to a tumour (statistically significant using mabs 3851 and 27). The staining frequency of normal colon mucosa in cases of colon cancer did not differ from that in the normal controls. Poly-CEA and the anti-ganglioside mabs C 50 and 19-9 revealed no tumour selectivity. A pronounced goblet cell staining was seen using C 50, C 242 and 19-9.