True histiocytic lymphoma of the esophagus in an HIV-positive patient: an ultrastructural study

A 56-year-old white woman, seropositive for human immunodeficiency virus for 18 months without signs of acquired immunodeficiency syndrome, presented with retrosternal pain and progressive dysphagia secondary to an exophytic esophageal mass. Biopsies of the tumor showed a malignant neoplasm composed of pleomorphic, noncohesive cells growing in a diffuse, sheet-like fashion. Immunohistochemically, tumor cells were nonreactive with epithelial, lymphoid, neural, and monocyte/macrophage markers. Despite the noncontributory immunohistochemical findings, ultrastructural study of the tumor cells revealed convincing histiocytic features. Individual cells possessed long, slender filopodial projections, prominent Golgi apparatus, residual bodies, rare lysosomes, and prelysosomes. Immunoglobulin heavy chain and T-cell receptor gamma gene rearrangement studies detected no evidence of a clonal gene rearrangement. The patient responded poorly to chemotherapy and died 5 months after her initial symptom of dysphagia.     

Imaging features of pancreatoblastoma: a case report

We present a patient with pancreatoblastoma along with a discussion of various cross-sectional imaging features. The tumor was a large multilocular cystic mass with solid components in the left retroperitoneal space. There were fine internal echoes on ultrasonography, and the signal intensity was high on both T1- and T2-weighted MR images in most of the locules, suggesting the presence of hemorrhagic debris. Among the various retroperitoneal organs displaced by the tumor, only the pancreatic tail was inseparable from the mass, suggesting that the pancreatic tail was the origin of the tumor. Pancreatoblastoma should be included in the differential diagnosis when a large left upper quadrant mass with these imaging features is seen in infants and young children.     

Morphological investigation of the enteric nervous system in Hirschsprung's disease and hypoganglionosis using whole-mount colon preparation

BACKGROUND/PURPOSE: A suction rectal mucosal biopsy with positive staining for acetylcholinesterase is a useful test for diagnosis of Hirschsprung's disease (HD). However, hypoganglionosis has not been diagnosed by a rectal mucosal biopsy. The authors morphologically examined the enteric nervous systems in HD and hypoganglionosis patients using whole-mount preparations. METHODS: Six HD patients, two hypoganglionosis patients, and 10 with normally innervated colons were examined. Colonic specimens were incubated with the primary antibodies against protein gene product 9.5 (PGP 9.5) mixed with S-100b protein, tyrosine hydroxylase (TH), calcitonin gene-related peptide (CGRP), substance P (SP), and neurofilament protein 200 kDa (NFH). They were observed by histochemical technique using light-microscopy in whole-mount preparations. RESULTS: The aganglionic distal colon had thick nerve strands stained with PGP 9.5 mixed with S100 or NFH located in the layer between the longitudinal muscle and the circular one, and the submucosal layer. The nerve strands in the myenteric layer contained few CGRP- and SP-positive fibers and ran along the long axis of the intestine. Ganglion cells appeared along with those thick nerve strands in the transitional zone of HD. In hypoganglionosis, we found small myenteric ganglia with no thick nerve strands. CONCLUSIONS: The enteric nervous system in oligoganglionic segments of HD morphologically differed from the one in hypoganglionosis. A suction rectal mucosal biopsy would be of no use in the diagnosis of hypoganglionosis.     

Effects of bacterial endotoxin on the contraction and relaxation responses of the rabbit cavernous smooth muscles

PURPOSE: We evaluated effects of bacterial endotoxin during septicemia on contraction and relaxation responses of cavernous smooth muscles in rabbits. MATERIALS AND METHODS: We performed isometric tension studies with norepinephrine (NE), endothelium-dependent and endothelium-independent vasodilators, and nonadrenergic noncholinergic (NANC)-selective electrical field stimulation on the muscle strips of control and endotoxin (lipopolysaccharide; LPS)-treated rabbits. To determine reversibility of the LPS effects on the cavernous smooth muscle, the contraction and relaxation studies were repeated after resting the strips for 1 day at 4C. We also investigated the effect of the nonspecific nitric oxide synthase (NOS) inhibitor (NW-nitro-L-arginine methyl ester; L-NAME) and the selective immunologic NOS inhibitor (aminoguanidine) on reactivity of the strips to NE and acetylcholine. RESULTS: Contractile response to NE was significantly (p <0.01) reduced in the cavernous smooth muscles from the systemically and locally LPS-treated rabbits, compared with control group. Both aminoguanidine and L-NAME markedly improved the diminished contraction of the strips. Relaxation response to endothelium-dependent agonists (acetylcholine and bradykinin) was significantly (p <0.05) decreased in the LPS-treated groups, compared with the control group but not to endothelium-independent vasodilators (papaverine and verapamil) and NANC-selective electrical field stimulation. L-NAME completely inhibited the relaxation response to acetylcholine in the control and LPS-treated groups but aminoguanidine did not. The impaired contraction and relaxation of the strips was completely restored after resting for 1 day. CONCLUSIONS: Bacterial endotoxin may cause non-endothelial overproduction of NO and inhibition of endothelium-derived NO production, which may contribute to impairment of contraction and relaxation of rabbit cavernous smooth muscles.     

Involvement of endothelial nitric oxide synthase in the impaired endothelium-dependent relaxation of cavernous smooth muscle in hypercholesterolemic rabbit

The present study was designed to evaluate whether functional impairment and/or protein expression of constitutive nitric oxide synthase (cNOS; endothelial NOS [eNOS] and neuronal NOS[nNOS]) was involved in impairment of endothelium-dependent relaxation of cavernous smooth muscle in hypercholesterolemic rabbits. New Zealand White rabbits were randomly divided into control and experimental groups. The control group (n=20) received a regular diet, while the two experimental groups (n=20 for each) were fed a 2% cholesterol diet for 4 and 8 weeks, respectively. We conducted isometric tension studies with endothelium-dependent and endothelium-independent vasodilators with or without preincubation with L-arginine and nonadrenergic, noncholinergic (NANC)-selective electrical field stimulation on isolated strips of corpus cavernosum. Expression of cNOS (eNOS and nNOS) protein was assessed by Western blot analysis. cNOS activities in both cytosolic and particulate fractions were measured by determining the conversion of L-[U-14C] arginine to L-[U-14C] citrulline. Blood levels of cholesterol were significantly higher (P < 0.01) in the experimental groups than in the control group. The relaxation responses to endothelium-dependent agents (acetylcholine and adenosine 5'-diphosphate [ADP]) were significantly reduced (P < 0.05) in both experimental groups, regardless of their incubation with L-arginine, compared with the control group. However, no differences were found among the three groups in the relaxation response to endothelium-independent agents (papaverine and nitroprusside) and to NANC-selective electrical field stimulation. There was no difference in immunoreactive nNOS from cytosolic and particulate fractions between the cavernous tissues of the control and experimental groups. nNOS protein levels in the particulate fractions were markedly lower than in the cytosolic fractions. The particulate cNOS activity was significantly decreased (P < 0.05) in the experimental groups compared with the control group, while the cytosolic cNOS activity in the experimental groups was not different from that found in the control group. Therefore, it is concluded that functional impairment of eNOS, rather than of nNOS, may lead to impairment of cavernous smooth muscle relaxation in response to endothelium-mediated stimuli in hypercholesterolemic rabbits.     

Synthesis andin vitro antibacterial activity of quaternary ammonium cephalosporin derivatives bearing oxazolidinone moiety

Several oxazolidinones having amine moiety were prepared to form a quaternary ammonium salt with cephalosporin nucleus, and antibacterial activity of the quaternary ammonium cephalosporin derivatives bearing oxazolidinone moiety were examined particularly with expectation of dual activity. However, the cephalosporin-oxazolidinone compounds revealed rather weaker antibacterial activity in vitro than their parent oxazolidinone and cephalosporin without showing any characteristic activity as expected.     

Synthesis andin vitro antibacterial activity of C-3′ pyridinium cephalosporin derivatives

The quaternary ammonium cephalosporin derivatives were prepared with various pyridines substituted at the 3 or/and 4 position. Their in vitro antibacterial activities were determined and substituent effect on pyridine nucleus was studied. Preparation of substituted pyridines are also described.     

Fucosidosis: four new mutations and a new polymorphism

Fucosidosis is a rare lysosomal storage disease due to a nearlycomplete deficiency of -L-fucosidase (EC 3.2.1.51 [EC] ). In thisstudy, all 8 exons of the -L-fucosidase structural gene (FUCA-1)were amplified by PCR methods, and the amplified products weresubcloned and sequenced. Five patient groups with fucosidosiswere selected according to their ethnic backgrounds and haplotypesfor RFLPs in FUCA-1. Four presumptive disease causing mutationswere detected: 1) A major deletion of DNA containing the lasttwo exons of FUCA-1 in two Algerian siblings. 2) A G to T mutationin exon 6 resulting in an in-frame termination codon (E375X)in eight Hispanic patients from Colorado and New Mexico. 3)A G to A mutation (G60D) in exon 1 in four Italian patientsand in three related French-American (Cajun) patients. ThisG60D mutation creates a unique site for Afl III. 4) A frameshiftmutation resulted from a two-base deletion in exon 2 (K151fs)in an Italian patient. This deletion obliterates a unique BstXIsite and creates a new BpmI site, and was found in only thispatient and in only one allele. The rationale for proposingthese defects as disease causing mutations includes pedigreeanalysis and the predicted consequences of each defect uponthe activity and the concentration of the enzyme. An A to Gtransition (Q281R) in exon 5 was found to be present in homozygousform in affected patients and also in normal subjects; it appearsto be a newly identified polymorphism. It causes a charge changeand may be responsible for the electrophoretic variant phenotypeof fucosidosis. This polymorphism is inherited concordant withthe RFLP PvuII—BglI haplotype 2 – 2, 2 – 2.The 4 new mutations identified here comprise 70% of allelesof the 25 fucosidosis patients in our study.     

Survey of attitudes among general practitioners regarding the introduction of a personal computer medical network system in community health care]

General practitioners (GPs) play an important part in community health care. Their opinion regarding introduction of a medical information network system using a personal computer and factors influencing the decision to introduce such a system were surveyed among 977 randomly sampled GPs. A response from 727 GPs was obtained. Based on a two stage selection method, 20 factors were selected as effective factors among the 73 factors surveyed, with the following results: (1) Responses to the question concerning the approval of system introduction were classified into three groups: "not necessary + too early to make a decision (DA)" (DA group), "approve (A)" (A group) and "undecided (UD)" (UD group). Each group had nearly equal numbers of respondees. (2) Significant effective factors were "experience with personal computers", "a desire to use a personal computer", "a desire to use a computer-diagnosis-system", "cost", and "a volition to operate a computer by himself". (3) The "A group" had high experience and affirmative opinions, while the "DA group" had low experience and negative opinions. The "UD group" also tended to respond with "do not know" regarding the factors. (4) Approval of system introduction requires providing basic knowledge on computers, opportunities for positive experience with computers, and practical examples of problem solutions in a general practitioner's work.     

Cavernous sinus hemangioma treated with gamma knife radiosurgery: usefulness of SPECT for diagnosis--case report

A 79-year-old female presented with cavernous sinus hemangioma manifesting as double vision due to right oculomotor and trochlear nerve pareses. Computed tomography and magnetic resonance imaging revealed bony erosion and a right cavernous sinus tumor with "tail sign" after contrast medium administration. Thallium-201 (201Tl) single photon emission computed tomography (SPECT) showed low uptake within the tumor, and technetium-99m-human serum albumin-diethylenetriaminepenta-acetic acid SPECT disclosed high uptake within the tumor. 201Tl SPECT usually shows very high uptake in meningiomas and malignant tumors, so the tumor was considered to be an unrelated benign tumor. The patient underwent partial resection of the tumor. Histological examination of the specimen confirmed cavernous hemangioma. The oculomotor nerve paresis partially improved. Gamma knife radiosurgery was carried out 4 months after the operation. The tumor markedly shrank with full recovery of extraocular movement 6 months after radiosurgery. SPECT is useful for distinguishing cavernous sinus hemangiomas from other cavernous tumors. Radiosurgery should be performed after partial resection or biopsy for cavernous sinus hemangiomas and may be the initial treatment for patients with small cavernous sinus hemangioma if the diagnosis can be established based on neuroimaging.