Imprint cytology of extraskeletal mesenchymal chondrosarcoma of the perineum: a case report

BACKGROUND: Extraskeletal mesenchymal chondrosarcoma (EMC) is an uncommon soft tissue tumor, occurring mainly in the lower limbs, meninges and retroperitoneum. EMC of the female genital tract is extremely rare, and the cytologic literature is scarce. CASE: A 43-year-old female with a growing perineal mass underwent excision of the tumor. Pathologic examination of the rumor revealed a characteristic two-cell pattern of primitive small cells and cartilaginous tissue. A diagnosis of EMC of the perineum was made. Imprint cytology from surgical material showed a cluster of small round cells with a focal hemangiopericytomalike arrangement and islets of cartilage. The cartilaginous cells reacted with S-100 protein immunocytochemically. CONCLUSION: The characteristic features of EMC, a hemangiopericytomalike arrangement of small cells and S-100-positive cartilaginous cells, may be helpful in diagnosing EMC and differentiating it from other perineal tumors.     

Pulmonary blastomycosis masquerading as metastatic disease in the lung: a case report

We report a case of pulmonary blastomycosis appearing as metastatic laryngeal squamous cell carcinoma. Pulmonary blastomycosis was discovered as right lower lobe subpleural activity consistent with metastatic disease on a positron emission tomographic (PET) scan following total laryngectomy and bilateral neck dissection for locally invasive laryngeal squamous cell carcinoma. A computed tomographic (CT) scan of the chest showed a right lower lobe, subpleural pulmonary nodule. CT-guided fine-needle aspiration of the nodule revealed broad-based budding yeast consistent with blastomycosis. To our knowledge, this is the first case of a PET-positive pulmonary blastomycosis lesion mimicking pulmonary malignancy reported in the literature.     

The yeast polyadenylate-binding protein (PAB1) gene acts as a disease lesion mimic gene when expressed in plants

We have expressed the gene (PAB1) encoding the yeast polyadenylate-binding protein (Pab1p) in tobacco. Plants that accumulate the Pab1p display a range of abnormalities, ranging from a characteristic chlorosis in leaves to a necrosis and large inhibition of growth. The severity of these abnormalities reflects the levels of yeast Pab1p expression in the transgenic plants. In contrast, no obvious differences could be seen in callus cultures between the transgene and vector control. Plants that display PAB-associated abnormalities were resistant to a range of plant pathogens, and had elevated levels of expression of a pathogenesis-related gene. These two properties – impairment of growth and induction of defense responses – indicate that the yeast PAB1 gene can act as a disease lesion mimic gene in plants.     

PNA zipper as a dimerization tool: Development of a bZip mimic

The article describes the use of a PNA duplex (PNA zipper) as a tool to dimerize or bring in close proximity two polypeptides or protein domains. The amino acid sequence to be dimerized is covalently bound to complementary PNA sequences. Annealing of the PNA strands results in dimer formation. To test the ability of the “PNA‐zipper” as a dimerization tool, we designed a GCN4 mimetic, where the leucine‐zipper dimerization domain was replaced by the PNA zipper, whereas the basic DNA‐binding domain was covalently attached to the PNA. The molecule was assembled by chemical ligation of the peptide corresponding to the DNA‐binding domain of GCN4 modified with a succinyl thioester with two complementary PNAs harboring a cysteine residue. Electromobility‐shift experiments show the ability of the PNA zipper‐GCN4 to bind selected DNA duplexes. The PNA zipper‐GCN4 binds both the TRE and CRE DNA sites, but it does not bind TRE and CRE mutants containing even a single base mutation, as the native GCN4. The ability to fold upon complexation with DNA was investigated by CD. A good correlation between the ability of the PNA zipper‐GCN4 to fold into α helices and the ability to bind DNA was found. © 2010 Wiley Periodicals, Inc. Biopolymers 93: 434–441, 2010. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com     

Good practice in head and neck fine needle aspiration cytology as assessed by CUSUM

Providing data as evidence of good practice is becoming imperative to meet the demands of professional revalidation and clinical governance. Sensitivity and specificity are common performance measures in fine needle aspiration (FNA) but are vulnerable to discordant analytical methods. We introduce a CUSUM technique and show how it may be used to show attainment and maintenance of proficiency in head and neck (H&N) FNA. In addition, we show how it can be used to compare practices and demonstrate different performance for FNAs from different tissues; a fact that must be recognized by anyone devising minimum performance values.     

Studies on the mechanism of resistance to Bipolaris sorokiniana in the barley lesion mimic mutant bst1

The Bipolaris sorokiniana tolerant 1 ( bst1 ) barley mutant is derived from fast neutron-irradiated seeds of wild-type Bowman( Rph3 ). The induced mutation was genetically localized to a position on chromosome 5HL distal to the centromere using amplified fragment length polymorphism markers. In addition, the defence responses and related gene expression in the bst1 mutant after fungal challenge were compared with those occurring in wild-type plants. Hydrogen peroxide generation, determined by 3,3-diaminobenzidine staining, revealed a clearly reduced level of bst1 , compared with the wild-type, during the entire experimental time: 8–120 h post-inoculation (hpi). At 48 hpi, the wild-type samples displayed twice as much fungal mass and three times greater H₂O₂ production than bst1 . At the same time, staining of B. sorokiniana showed less fungal growth in the spontaneous lesions of bst1 compared with the wild-type. Monitoring of defence-related genes at 48 hpi demonstrated strong expression of PR-1a , PR-2 , PR-5 and PR-10 in bst1. A gene coding for a unique oxidoreductase enzyme, designated as HCP1 , was expressed at much higher levels in inoculated leaves of the bst1 mutant than in those of the wild-type plant. Taken together, the results suggest that the defence to B. sorokiniana largely relies on salicylic acid-responsive pathogenesis-related ( PR ) genes, as well as selected reactive oxygen species and unknown HCP1 -associated factors.     

Muscle spindles in the deep muscles of the human neck: a morphological and immunocytochemical study.

Muscle spindle density is extremely high in the deep muscles of the human neck. However, there is a paucity of information regarding the morphology and immunoreactivity of these muscle spindles. The objective of this study was to investigate the intrafusal fiber content and to assess the myosin heavy chain (MyHC) composition of muscle spindles from human deep neck muscles. In addition to the conventional spindles containing bag(1), bag(2), and chain fibers (b(1)b(2)c spindle), we observed a number of spindles lacking bag(1) (b(2)c spindle) or bag(2) (b(1)c spindle) fibers. Both bag(1) and bag(2) fibers contained slow tonic MyHCs along their entire fiber length and MyHCI, MyHCIIa, embryonic, and alpha-cardiac MyHC isoforms along a variable length of the fibers. Fetal MyHC was present in bag(2) fibers but not in bag(1) fibers. Nuclear chain fibers contained MyHCIIa, embryonic, and fetal isoforms with regional variations. We also compared the present data with our previous results obtained from muscle spindles in human biceps brachii and the first lumbrical muscles. The allotment of numbers of intrafusal fibers and the MyHC composition showed some muscle-related differences, suggesting functional specialization in the control of movement among different human muscles.