Increased activity on radiocolloid scintigraphy in splenic hamartoma

A higher uptake of radiocolloid in a splenic tumor than in the rest of the spleen was observed in a 17-year-old boy. The pathologic diagnosis of the surgically resected tumor was hamartoma composed of anomalous mixtures of splenic elements, and radiocolloid was considered to be distributed to reticuloendothelial cells in the tumor. Radiocolloid scintigraphy, which can demonstrate the function of the reticuloendothelial system, is helpful in the diagnosis of splenic hamartoma.     

Mechanisms involved in aggravation of ethanol-induced gastric mucosal lesions in adrenalectomized rats

Effects of adrenalectomy (AD) on ethanol-induced gastric injury and prostaglandin (PG) protection on the damage were investigated in rats and compared with those of N-ethylmaleimide (NEM), a sulfhydryl (SH) blocker, and diethyl maleate (DEM), a SH depletor. Oral administration of 100% ethanol (1 ml) induced elongated bands of hemorrhagic lesions in the corpus mucosa of sham operated rats, and these lesions were significantly prevented by 16,16-dimethyl PGE2 (dmPGE2, 10 micrograms/kg, s.c.). AD markedly enhanced the mucosal ulcerogenic responses caused by ethanol and abolished the protective effect of dmPGE2; this agent rather worsened the lesions, which appeared throughout the corpus mucosa. AD by itself enhanced the microvascular permeability in the gastric mucosa without any effect on SH contents. These alterations caused by AD were significantly reverted by hydrocortisone treatment (10 mg/kg/day for 2 weeks, s.c.). On the other hand, a single injection of NEM (10 mg/kg, s.c.) similarly enhanced the vascular permeability, worsened the ethanol-induced lesion, and mitigated the protective effect of dmPGE2 without altering mucosal SH contents, while DEM (1 ml/kg, s.c.) significantly reduced the mucosal SH levels and the lesions. These results suggest that AD worsened the mucosal lesions induced by ethanol, probably by enhancing the microvascular permeability, and this action may be due to a lack of steroid secretion but is not directly related to a mucosal SH deficiency.     

Emergence of mammals by emergency: exaptation

With the development of molecular embryology and the coming of the post‐genomic era, the molecular mechanisms of morphological evolution have recently begun to be elucidated. Whole genome sequences of many vertebrate species have been determined, and comparative genomics has suggested that one source of biodiversity is conserved non‐coding elements (CNEs), which may be involved in generating new networks of gene expression. Nishihara et al. (Genome Res. 2006; 16, 864) discovered retroposon (AmnSINE1s)‐derived CNEs in the human genome, and suggested that the AmnSINE1s obtained their function (i.e., exapted) in a common mammalian ancestor and are involved in generating mammalian‐specific morphology. Therefore, investigation of the function of AmnSINE1‐derived CNEs in morphogenesis helps us understand the molecular events of how mammals obtained their specific morphological characters by exaptation that occurred when the first mammalian ancestor emerged about 250 Ma (million years ago). Because there are more than 100 AmnSINE1‐derived CNE loci in the mammalian genome, a burst of exaptation of AmnSINE1s must have occurred, possibly triggered by the Permian‐Triassic mass extinction 250 Ma. In this review, we discuss morphological evolution of the mammalian‐specific characters including brain that were exapted after retrotransposition of AmnSINE1s by referring to two CNE loci described by Sasaki et al. (Proc. Natl. Acad. Sci. USA 2008; 105, 4220).     

Comparison Between Fenoterol and Fenoterol Plus Oxitropium Bromide Delivered by Metered-Dose Inhaler with InspirEase to Relieve Acute Asthma Attack

Although the inhalation of β₂-agonists has frequently been used to relieve acute asthma attacks, the efficacy of anticholinergic agents for acute asthma attacks still remains unclear. This study was designed to compare the inhalation of fenoterol and the inhalation of fenoterol plus oxitropium bromide delivered by a metered-dose inhaler with holding chamber (InspirEase) to relieve acute asthma attacks. To accomplish this, 69 patients who had presented with an acute asthma attack were randomized to receive either fenoterol (1 puff [200 μg/puff] every 1 min for 5 min; total 1000 μg) or fenoterol plus oxitropium bromide (2 puffs [100 μg/puff] every 1 min for 5 min; total 1000 μg). The peak expiratory flow (PEF) and forced expiratory volume in 1 sec (FEV) values were measured before treatment, and 1,15, 30, and 60 min after the inhalation therapy. The ratios of improvement, PEF (or FEV) after treatment divided by PEF (or FEV) before treatment, were also calculated. Thirty-three patients were evaluated in the combination group and 31 patients were evaluated in the fenoterol group. The PEF value at 60 min after inhalation therapy of the fenoterol plus oxitropium bromide group (261 ± 18 L/min, mean ± standard error) was significantly higher compared to that of the fenoterol group (210 ± 17 L/min). In addition, the ratios of improvement of PEF at 1, 15, 30, and 60 min after inhalation therapy were significantly higher in the fenoterol plus oxitropium bromide group compared with the fenoterol group.     

Vascular pseudoinvasion in a solitary Peutz‐Jeghers polyp in the ileum

A Peutz‐Jeghers polyp (PJP) is a hamartomatous lesion characterized by arborescent smooth muscle bundles covered with mucosa native to the site of involvement. PJPs in the small intestine may represent misplacement of non‐neoplastic epithelium into the submucosa, muscularis propria and subserosa. Although epithelial misplacement in PJPs is a well‐documented phenomenon, pseudoinvasion even into the vascular space in PJPs has not previously been reported. We report a case of a 22‐year‐old Japanese woman with a solitary PJP in the ileum. The ileal PJP in this patient showed epithelial herniation even into the vascular space. All the herniated epithelium, including the epithelial components invaginated into the vascular space, demonstrated features of pseudoinvasion, that is, presence of normal small intestinal type mucosa accompanied by the lamina propria, absence of any stromal desmoplastic reaction, and retention of the basal‐luminal gradient. Pathologists must be aware of the possibility of vascular pseudoinvasion in small intestinal PJPs to avoid overdiagnosis of carcinoma and resulting unnecessary major surgery.