CT appearances of hydatid disease at various locations

Hydatid disease has characteristic imaging features on CT, which allow accurate preoperative diagnosis in most cases. However, when it occurs at unusual locations the diagnosis is often difficult, especially as the imaging appearance varies at different sites. In this article we have presented a pictorial review of the CT features of disease due to Echinococcus granulosus at various sites in the human body.     

Characterization of a subtype of primary osteoclastoma: Extracellular calcium but not calcitonin inhibits aggressive HLA-DR-positive osteoclastoma possessing ‘functional’ calcitonin receptors

We report here a case of primary osteoclastoma that despite possessing HLA-DR-positive status and ‘functional’ calcitonin receptors, exhibited aggressive in vitro and in vivo bone resorptive activity. In the osteoclast bone slice assay employing scanning electron microscopy, the giant cell-mediated bone resorption was uninhibited by salmon calcitonin (10 nM) and significantly inhibited by raised extracellular calcium (20 mM). In Fura-2AM based microspectrofluorimetric assays, the presence of the ‘functional’ calcitonin receptors was ascertained by a rise in intracellular calcium induced by calcitonin and high extracellular calcium. These findings provide evidence for a hitherto unrecognized subtype of giant cells that have HLA-DR-positive status, exhibit avid bone resorptive activity, but remain insensitive to calcitonin despite possessing calcitonin receptors.     

Immunosenescence of human NK cells: effects on tumor target recognition, lethal hit and interferon sensitivity.

Previous results from this laboratory have shown the preservation of non-MHC-restricted, constitutive oncolytic activity of human peripheral blood NK cells in the elderly as assessed by the chromium release assay which quantitates the lytic endpoint at the cell population level. We have now addressed this senescence-related change at single-cell level using 101 blood samples. Both the efficiency of the initial tumor target binding step i.e., recognition of K562, the NK-sensitive erythroleukemia cell line, as well as the ability of NK cells to deliver lethal hit are highly conserved during healthy aging. In fact, the elderly exhibit a statistically significant, moderately higher frequency of active killers among circulating lymphocytes. Analyzed in another way, a majority of "high NK responders" were found to be older donors, while none in the "low NK responders" group were > 70 years old. Gamma interferon, a gene product as well as an autocrine activator of NK cells, is effective in converting non-lytic "pre-NK" cells to active killers at single-cell level. This in vitro cytokine sensitivity of NK cells is unaltered during immune senescence. The intactness of the NK cell's capacity to be modulated may be vital in both tumor resistance and host viral defenses of aged humans.     

Toxoplasmosis Presenting as Hyper Viscosity Syndrome due to Polyclonal Gammopathy

We are presenting a rare case of toxoplasma lymphadenopathy with hyper viscosity syndrome due to polyclonal gammopathy. A 30 year old female presented with generalized lymphadenopathy. Lymph node biopsy findings suggestive of toxoplasmosis were confirmed on serology. Bone marrow aspiration showed 50 % plasma cells. On serum electrophoresis broad, diffuse band noted, indicative of polyclonal gammopathy. M band was absent. The patient was immunocompetent and presented with hyper viscosity syndrome masking the symptoms of underlying toxoplasmosis.     

Maldistribution of pulmonary blood flow in patients after the Fontan operation is associated with worse exercise capacity

Background

Maldistribution of pulmonary artery blood flow (MPBF) is a potential complication in patients who have undergone single ventricle palliation culminating in the Fontan procedure. Cardiovascular magnetic resonance (CMR) is the best modality that can evaluate MPBF in this population. The purpose of this study is to identify the prevalence and associations of MPBF and to determine the impact of MPBF on exercise capacity after the Fontan operation.

Methods

This retrospective single-center study included all patients after Fontan operation who had maximal cardiopulmonary exercise test (CPET) and CMR with flow measurements of the branch pulmonary arteries. MPBF was defined as >?20% difference in branch pulmonary artery flow. Exercise capacity was measured as percent of predicted oxygen consumption at peak exercise (% predicted VO₂). Linear and logistic regression models were used to determine univariate and multivariable predictors of exercise capacity and correlates of MPBF, respectively.

Results

A total of 147 patients who had CMR between 1999 and 2017 were included (median age at CMR 21.8?years [interquartile range (IQR) 16.5–30.6]) and the median time between CMR and CPET was 2.8?months [IQR 0–13.8]. Fifty-three patients (36%) had MPBF (95% CI 29–45%). The mean % predicted VO₂ was 63?±?16%. Patients with MPBF had lower mean % predicted VO₂ compared to patients without MPBF (60?±?14% versus 65?±?16%, p?=?0.04). On multivariable analysis, a lower % predicted VO₂ was independently associated with longer time since Fontan, higher ventricular mass-to-volume ratio, and MPBF. On multivariable analysis, only compression of the branch pulmonary arteries by the ascending aorta or aortic root was associated with MPBF (OR 6.5, 95% CI 5.6–7.4, p?<?0.001).

Conclusion

In patients after the Fontan operation, MPBF is common and is independently associated with lower exercise capacity. MPBF was most likely to be caused by pulmonary artery compression by the aortic root or the ascending aorta. This study identifies MPBF as an important risk factor and as a potential target for therapeutic interventions in this fragile patient population.