Dorsal Spinal Ligamentum Flavum Thickening: A Magnetic Resonance Imaging Study

Study DesignA retrospective radiological study of the ligamentum flavum (LF).PurposeWe determined the relationship of dorsal spinal LF thickening with age and sex using magnetic resonance imaging (MRI). We also determined whether LF thickening has a predominant tendency to occur at a specific dorsal level and on a specific side.Overview of LiteratureMany researchers have studied LF thickness at dorsal levels in patients with compressive myelopathy. However, there is a dearth of literature pertaining to the study of dorsal LF thickness in patients without myelopathy.MethodsLF thickness was measured at dorsal levels from T1 to T12 on both sides using MRI in 100 individuals. The patients were divided into three groups based on age: 20 to 40, 41 to 60, and >60 years. On axial T2-weighted imaging at the mid-disc level, LF thickness was measured perpendicular to the lamina border, either at half the length of LF or at maximum thickness, whichever was greater.ResultsWe found that LF thickness does not increase significantly with increasing age and there was no significant disparity in LF thickness between the sides and sexes. We also found that there was a significant increase in LF thickness at the T10–T11 level (mean value, 3.27±0.94 mm).ConclusionsLF thickness does not appear to have any side/sex dominance. LF thickening has a predominant tendency to occur specifically at the T10–T11 level. This may be due to maximum tensile strength and mobility at this level. Because there is an increased tendency for LF thickening at the T10–T11 level, this may be used as a reference point for counting the vertebral levels

Woody plant seedling distribution under invasive Lantana camara thickets in a dry-forest plot in Mudumalai, southern India

Lantana camara, a shrub of Central and South American origin, has become invasive across dry forests worldwide. The effect of the thicket-forming habit of L. camara as a dispersal and recruitment barrier in a community of native woody seedlings was examined in a 50-ha permanent plot located in the seasonally dry forest of Mudumalai, southern India. Sixty 100-m(2) plots were enumerated for native woody seedlings between 10-100 cm in height. Of these, 30 plots had no L. camara thickets, while the other 30 had dense thickets. The frequency of occurrence and abundance of seedlings were modelled as a function of dispersal mode (mammal, bird or mechanical) and affinities to forest habitats (dry forest, moist forest or ubiquitous) as well as presence or absence of dense L. camara thickets. Furthermore, frequency of occurrence and abundance of individual species were also compared between thickets and no L. camara. At the community level, L. camara density, dispersal mode and forest habitat affinities of species determined both frequency of occurrence and abundance of seedlings, with the abundance of dry-forest mammal-dispersed species and ubiquitous mechanically dispersed species being significantly lower under L. camara thickets. Phyllanthus emblica and Kydia calycina were found to be significantly less abundant under L. camara, whereas most other species were not affected by the presence of thickets. It was inferred that, by affecting the establishment of native tree seedlings, L. camara thickets could eventually alter the community composition of such forests

Long-Term Environmental Correlates of Invasion by <i>Lantana camara</i> (Verbenaceae) in a Seasonally Dry Tropical Forest

<div><p>Invasive species, local plant communities and invaded ecosystems change over space and time. Quantifying this change may lead to a better understanding of the ecology and the effective management of invasive species. We used data on density of the highly invasive shrub <i>Lantana camara</i> (lantana) for the period 1990–2008 from a 50 ha permanent plot in a seasonally dry tropical forest of Mudumalai in southern India. We used a cumulative link mixed-effects regression approach to model the transition of lantana from one qualitative density state to another as a function of biotic factors such as indicators of competition from local species (lantana itself, perennial grasses, invasive <i>Chromolaena odorata</i>, the native shrub <i>Helicteres isora</i> and basal area of native trees) and abiotic factors such as fire frequency, inter-annual variability of rainfall and relative soil moisture. The density of lantana increased substantially during the study period. Lantana density was negatively associated with the density of <i>H. isora</i>, positively associated with basal area of native trees, but not affected by the presence of grasses or other invasive species. In the absence of fire, lantana density increased with increasing rainfall. When fires occurred, transitions to higher densities occurred at low rainfall values. In drier regions, lantana changed from low to high density as rainfall increased while in wetter regions of the plot, lantana persisted in the dense category irrespective of rainfall. Lantana seems to effectively utilize resources distributed in space and time to its advantage, thus outcompeting local species and maintaining a population that is not yet self-limiting. High-risk areas and years could potentially be identified based on inferences from this study for facilitating management of lantana in tropical dry forests.</p></div

Frequency of occurrence (bars) and biomass (line) of lantana in the MFDP from 1990–2008.

<p>Light grey through dark grey represent the increasing density of lantana, i.e, from ‘absent’ through ‘present’, ‘common’ and ‘dense’ to ‘very dense’. The five density categories of lantana occurred with varying frequencies across the time period sampled; the lower density categories occurred less frequently and the higher density categories occurred more frequently with time. Gaps and dotted lines indicate fire years or missing data. The dry weight biomass of lantana is based on a study conducted in the year 2011. Note that for the purpose of analyses, the ‘absent’ and ‘present’ categories were combined to form the low-density ‘present’ category while the ‘common’ and ‘dense’ categories were combined to form a moderate density ‘common’ category.</p

Interannual variability in rainfall and fire at the Mudumalai Forest Dynamics Plot.

<p>The solid line and dots represent total annual rainfall (mm) while the grey bars represent the percentage of 10 m×10 m plots burnt each year. It must be noted that fires usually occur during the dry season of each year and are not related to the total rainfall in that year.</p

Output of the simplified cumulative link mixed model.

<p>All predictors, corresponding to the time step immediately before that of the current time step, were scaled by subtracting the mean and dividing by the standard deviation in order to make them comparable. The overall predictability of the model was high, with a gamma score of 0.78. TWI – topographic wetness index of a cell, ‘×’ – interactions between factors.</p

Ultrasound Guided Fine-Needle Aspiration Cytology (FNAC) of Portal Vein Thrombus: A Novel Diagnostic and Staging Technique for Occult Hepatocellular Carcinoma

Introduction: The diagnosis of Hepatocellular Carcinoma (HCC) is usually established using noninvasive radiological imaging and tumor markers. The stage at diagnosis is a critical factor in the treatment, course and prognosis of HCC. Patients with Tumor Portal vein thrombus (PVT) are considered to have an advanced disease and are only offered palliative therapy. Therefore, every possible attempt should be made to accurately stage HCC. Fine-needle aspiration cytology (FNAC) of PVT is an effective procedure for diagnosing and staging HCC. We present a case where we used Ultrasound (USG) guided FNAC of a PVT to successfully diagnose and stage HCC in the absence of a well-defined liver mass on imaging. Case report: A 43-year-old Hepatitis B surface antigen positive male presented with a 3-month history of fatigue, jaundice and fever. On examination he had hepatomegaly. His liver function tests were elevated, but his alpha-fetoprotein was normal. USG and Computed Tomography (CT) showed a thrombus in the portal vein but failed to show a well-defined liver lesion. FNAC was taken from the PVT, which was positive for malignancy. He was offered palliative chemotherapy and a steroid for his pyrexia. He is on follow-up. Conclusion: FNAC is a safe, quick, easy and economical technique to diagnose and stage HCC in the presence of portal vein thrombus, especially in patients where the tumor is occult on imaging. It also affords an accurate method to differentiate between malignant and nonmalignant PVT, thereby aiding appropriate therapeutic decision making. [Arch Clin Exp Surg 2014; 3(2.000): 129-132

Dispersal by generalist frugivores affects management of an invasive plant

In the past century, our understanding of the processes driving plant invasion and its consequences for natural and anthropogenic systems has increased considerably. However, the management of invasive plants remains a challenge despite ever more resources being allocated to their removal. Often invasive plants targeted for `eradication' are well-established, have multiple modes of reproduction, long-term seed banks, and strong associations with native and non-native mutualists that ensure dispersal and facilitate spread. The pantropical weed, Lantana camara (Lantana), is one of the most invasive woody plants globally. We illustrate that, for Lantana, eradication is an unrealistic management goal given the short-term removal approaches, irrespective of the effectiveness of removal methods. We assessed the role of dispersal by avian frugivores in the recolonization of managed areas by Lantana in the seasonally dry, tropical forests of northern and southern India. We estimated the distribution of Lantana, its dispersal potential and the proximity between managed areas and source populations. We found that Lantana was dispersed by many generalist frugivorous birds and that most managed areas were well within the median dispersal distance from source plants facilitating rapid recolonization of managed areas. We conclude that given the difficulty of eradicating long-established invasive plants, management practices should entail long-term monitoring and control in priority areas for as long as Lantana occurs in the landscape

Haemosuccus pancreaticus: diagnostic and therapeutic challenges

AbstractBackgroundHaemosuccus pancreaticus (HP) is a rare cause of upper gastrointestinal bleeding. The objective of our study was to highlight the challenges in the diagnosis and management of HP.MethodsThe records of 31 patients with HP diagnosed between January 1997 and June 2008 were reviewed retrospectively.ResultsMean patient age was 34 years (11–55 years). Twelve patients had chronic alcoholic pancreatitis, 16 had tropical pancreatitis, two had acute pancreatitis and one had idiopathic pancreatitis. Selective arterial embolization was attempted in 22 of 26 (84%) patients and was successful in 11 of the 22 (50%). Twenty of 31 (64%) patients required surgery to control bleeding after the failure of arterial embolization in 11 and in an emergent setting in nine patients. Procedures included distal pancreatectomy and splenectomy, central pancreatectomy, intracystic ligation of the blood vessel, and aneurysmal ligation and bypass graft in 11, two, six and one patients, respectively. There were no deaths. Length of follow-up ranged from 6 months to 10 years.ConclusionsUpper gastrointestinal bleeding in a patient with a history of chronic pancreatitis could be caused by HP. Diagnosis is based on investigations that should be performed in all patients, preferably during a period of active bleeding. These include upper digestive endoscopy, contrast-enhanced computed tomography (CECT) and selective arteriography of the coeliac trunk and superior mesenteric artery. Contrast-enhanced CT had a high positive yield comparable with that of selective angiography in our series. Therapeutic options consist of selective embolization and surgery. Endovascular treatment can control unstable haemodynamics and can be sufficient in some cases. However, in patients with persistent unstable haemodynamics, recurrent bleeding or failed embolization, surgery is required

Biliary Cystadenomas: A Case for Complete Resection

Introduction and Objective. Biliary cystadenoma is a rare benign neoplasm of the liver with less than 200 cases being reported allover the world. We report a series of 13 cases highlighting the radiological findings and problems related to its management. Materials and Methods. Records of thirteen patients who underwent surgery for biliary cystadenomas, between March 2006 and October 2011, were reviewed retrospectively. Results. Majority of the patients were females (11 out of 13), with a median age of 46 (23–65) years. The most frequent symptom was abdominal pain (92%). Seven patients had presented with history of previous surgery for liver lesions. Five patients had presented with recurrence after partial resection for a suspected hydatid cyst and two after surgery for presumed simple liver cyst. Ten of the 13 patients had complete resection of the cyst with enucleation in 3 patients, 2 of whom in addition required T-tube drainage of the bile duct. There has been no recurrence during the follow-up period ranging from 3 months to 5 years. Conclusion. Biliary cystadenoma must be differentiated from other benign cysts. Hepatic resection or cyst enucleation is the recommended treatment option