Neurocysticercosis, IgG immunoglobulins, and nitric oxide

This study evaluated the role of parasite load and nitric oxide on IgG levels in neurocysticercosis. Total serum IgG, IgG antibodies specific for cysticercus antigens, and nitric oxide were compared between 85 neurocysticercosis patients, 65 with solitary cysts and 20 with multiple cysts, and 13 normal healthy controls. Sixty-six percent of patients were seropositive for cysticercus IgG antibodies. Among seropositive patients, IgG levels did not differ between those infected with multiple or solitary cysts whose serum nitric oxide levels were low (<40 nmol/ml). Among seropositive solitary cyst infected patients, IgG levels were significantly higher in those whose serum nitric oxide was low compared to those with high nitric oxide levels (p < 0.001). IgG levels were significantly higher in patients with multiple compared to single cyst infections among those negative for cysticercus antibodies (p < 0.001). Parasite load and nitric oxide modulated IgG production in neurocysticercosis. IgG levels were not determined by the number of infecting cysts in seropositive patients who did not mount a nitric oxide response. IgG production correlated to parasite load in patients negative for cysticercus antibodies.     

Reversible brain ischemia: lessons from transient ischemic attack

PURPOSE OF REVIEW: In recent years, there has been considerable scientific inquiry regarding transient ischemic attack. In an effort to synthesize at times conflicting data, this paper will review the recent evidence and provide a critical overview of reversible brain ischemia. RECENT FINDINGS: Transient ischemic attack is now understood to indicate a higher risk of recurrence than completed ischemic stroke. Efforts to unravel the mechanisms of this instability following transient ischemic attack using imaging studies have led to new concepts and definitions, and sparked further debate. While imaging has increased diagnostic certainty, it has yet to provide reliable prognostic markers. The evidence suggests that risk of clinical recurrence is most closely linked to the degree to which the initial deficit reverses. From a tissue level, however, there are also data to support the notion of a 'stroke-prone state' following both transient ischemic attack and completed stroke, suggesting that mechanistically they may be less distinct than previously thought. Transient ischemic attack may simply highlight the dynamic nature of all acute ischemic cerebrovascular syndromes. SUMMARY: Reversible brain ischemia is a harbinger for subsequent ischemic stroke. Although recent advances have focused on imaging markers, the most important predictor of risk following brain ischemia is degree of early clinical reversibility.     

Pseudo-subarachnoid hemorrhage in cerebellar infarction

Introduction  

The computed tomography (CT) appearance of subarachnoid hemorrhage (SAH) without subarachnoid blood has been labeled “pseudo-subarachnoid hemorrhage” (pseudo-SAH) and has been reported with several diffuse intracerebral insults including intrathecal contrast agents, meningitis, generalized cerebral edema, anoxic encephalopathy, and intracranial hypotension.     

Recurrent acute thyroid swellings because of pyriform sinus fistula

Anterior neck abscesses are not rare; but their origin from within the usually infection-resistant thyroid gland is not thought of in the first instance. We encountered 3 patients with differing presentations (tender nodule over anterior neck, recurrent abscess overlying the thyroid gland, and nonhealing fistula with inflammation of the anterior neck). These were caused by persistent embryological communication from the pyriform sinus to the thyroid gland to the left lobe. Excluding the first patient in whom an abnormal communication with oropharynx was suspected when actinomyces was detected in the aspiration cytology of a thyroid nodule, the other 2 patients underwent drainage as for any neck abscess. Fistulous communication was confirmed on barium swallow (in 2 patients) or computed tomographic scan (in 1 patient). En bloc excision of the affected thyroid along with the fistulous tract was performed in all patients. Long-term follow-up confirmed a cure.     

Molecular modeling studies of surface decoration of hemoglobin by maleimide PEG

Surface decoration of hemoglobin (Hb) with six copies of PEG-5K employing thiolation mediated PEGylation platform neutralizes the vasoaconstricive activity of acellular Hb. The molecular size homogeneity of hexaPEGylated Hb, in spite of the fact that the PEGylation is distributed at multiple sites and PEGylation at each of the sites is not quantitative, is an unusual aspect of this PEGylation reaction. We have introduced three cys residues-Cys-13 (alpha), Cys-111 (alpha), and Cys-13 (beta)-onto Hb by molecular modeling. This new mutant Hb with four reactive Cys residues has been used to build molecular models of PEGylated Hbs with two, four, six, and eight PEG-chains of different masses. The calculated loss of surface area was used to design and gain insight into the structure and the surface shielding of PEGylated Hbs. The modeling shows the adequate surface coverage of the protein hemoglobin with six copies of PEG-5K chains and also exhibits more surface coverage of the hemoglobin as compared to that afforded by two copies of PEG-20K chains.     

Genomic and surface proteomic analysis of the canine pathogen Staphylococcus pseudintermedius reveals proteins that mediate adherence to the extracellular matrix

Cell wall-associated (CWA) proteins made by Gram-positive pathogens play a fundamental role in pathogenesis. Staphylococcus pseudintermedius is a major animal pathogen responsible for the canine skin disease bacterial pyoderma. Here, we describe the bioinformatic analysis of the family of 18 predicted CWA proteins encoded in the genome of S. pseudintermedius strain ED99 and determine their distribution among a phylogenetically diverse panel of S. pseudintermedius clinical isolates and closely related species of the Staphylococcus intermedius group. In parallel, we employed a proteomic approach to identify proteins presented on the surface of strain ED99 in vitro, revealing a total of 60 surface-localized proteins in one or more phases of growth, including 6 of the 18 genome-predicted CWA proteins. Based on these analyses, we selected two CWA proteins (SpsD and SpsL) encoded by all strains examined and investigated their capacity to mediate adherence to extracellular matrix proteins. We discovered that SpsD and SpsL mediated binding of a heterologous host, Lactococcus lactis, to fibrinogen and fibronectin and that SpsD mediated binding to cytokeratin 10, a major constituent of mammalian skin. Of note, the interaction with fibrinogen was host-species dependent, suggestive of a role for SpsD and SpsL in the host tropism of S. pseudintermedius. Finally, we identified IgG specific for SpsD and SpsL in sera from dogs with bacterial pyoderma, implying that both proteins are expressed during infection. The combined genomic and proteomic approach employed in the current study has revealed novel host-pathogen interactions which represent candidate therapeutic targets for the control of bacterial pyoderma.     

Current status and future perspectives of magnetic resonance high-field imaging: a summary

There are several magnetic resonance (MR) imaging techniques that benefit from high-field MR imaging. This article describes a range of novel techniques that are currently being used clinically or will be used in the future for clinical purposes as they gain popularity. These techniques include functional MR imaging, diffusion tensor imaging, cortical thickness assessment, arterial spin labeling perfusion, white matter hyperintensity lesion assessment, and advanced MR angiography.     

Orbital aspergillus infection diagnosed by FNAC

Fungal infections of the orbit represent a small minority of orbital infections. However, due to the virulent nature of some of the fungal species, they can have a devastating effect on ocular functions. Most of these fungi are saprophytes, which cause opportunistic infections. Aspergillus is one such fungus that can cause infection at various sites in an immunosuppressed individual. Sinonasal aspergillus infection with orbital extension and orbital aspergillus infection progress relentlessly. They can have a precipitous clinical course resulting in total loss of vision. Fine needle aspiration cytology (FNAC) is rarely used as a preoperative diagnostic tool in the investigation of orbital mass lesions. Further, fungal infections of orbit are seldom diagnosed on FNAC. Two cases of fungal infection of the orbital and periorbital tissue diagnosed on FNAC are presented. A 50-year-old diabetic male presented with diminishing vision, pain, and forward protrusion of the left eye. On examination, he had upper eye lid fullness. A 55-year-old diabetic male presented with a swelling on the right upper eye lid. The patients were evaluated radiologically and then subjected to FNAC. The smears showed giant cells, histiocytes, epithelioid granulomas, and fungal hyphae. A diagnosis of fungal infection was arrived at which was subsequently confirmed by culture and biopsy. Orbital aspergillus infection can have a precipitous course. Computerized tomography and magnetic resonance imaging of the orbit provide crucial information. However, FNAC can help in making an early definitive diagnosis of fungal infection and thus obviate the need for a biopsy.