A Gastric Metastatic Lesion That Resembled Early-Stage Gastric Cancer on Endoscopy during Treatment for Recurrent Breast Cancer: A Case Report.

Breast cancer metastasis to the gastrointestinal tract is relatively rare. Patients with such disease often develop gastrointestinal symptoms, but it is sometimes asymptomatic. Endoscopic findings of gastric metastasis from breast cancer markedly vary from benign to malignant, and even in suspected malignant cases, it is often difficult to differentiate between primary and metastatic disease. We experienced a case in which an endoscopic examination performed during the treatment for metastatic breast cancer resembled an early-stage gastric cancer. A 71-year-old woman underwent curative surgery for right breast cancer 16 years previously. She underwent endoscopic submucosal dissection for early-stage gastric cancer 5 years ago. Two years ago, she developed metastatic disease in the lungs and mediastinal lymph nodes, and endocrine therapy was administered. At the same time, a follow-up endoscopy revealed a new elevated lesion, suspected to be an early-stage gastric cancer. However, histological diagnosis of the biopsy was metastasis of breast cancer. One and a half years later, a follow-up endoscopy revealed a gastric lesion that had reduced in size. She is still alive, having received a variety of systemic treatments. Patients with metastatic breast cancer are experiencing prolonged survival. Thus, follow-up endoscopy should be considered after the diagnosis of gastrointestinal metastasis considering the risk of lethal conditions, such as gastrointestinal bleeding and perforation. Our case serves as a reminder to clinicians how difficult it is to determine whether a gastric lesion is primary or metastatic based on endoscopic findings and the importance of communication with endoscopists and pathologists.

Impairment of heme biosynthesis induces short circadian period in body temperature rhythms in mice.

It has been demonstrated that the function of mammalian clock gene transcripts is controlled by the binding of heme in vitro. To examine the effects of heme on biological rhythms in vivo, we measured locomotor activity (LA) and core body temperature (T(b)) in a mouse model of porphyria with impaired heme biosynthesis by feeding mice a griseofulvin (GF)-containing diet. Mice fed with a 2.0% GF-containing diet (GF2.0) transiently exhibited phase advance or phase advance-like phenomenon by 1-3 h in terms of the biological rhythms of T(b) or LA, respectively (both, P < 0.05) while mice were kept under conditions of a light/dark cycle (12 h:12 h). We also observed a transient, ~0.3 h shortening of the period of circadian T(b) rhythms in mice kept under conditions of constant darkness (P < 0.01). Interestingly, the observed duration of abnormal circadian rhythms in GF2.0 mice lasted between 1 and 3 wk after the onset of GF ingestion; this finding correlated well with the extent of impairment of heme biosynthesis. When we examined the effects of therapeutic agents for acute porphyria, heme, and hypertonic glucose on the pathological status of GF2.0 mice, it was found that the intraperitoneal administration of heme (10 mg·kg(-1)·day(-1)) or glucose (9 g·kg(-1)·day(-1)) for 7 days partially reversed (50%) increases in urinary δ-aminolevulinic acids levels associated with acute porphyria. Treatment with heme, but not with glucose, suppressed the phase advance (-like phenomenon) in the diurnal rhythms (P < 0.05) and restored the decrease of heme (P < 0.01) in GF2.0 mice. These results suggest that impairments of heme biosynthesis, in particular a decrease in heme, may affect phase and period of circadian rhythms in animals.

Characterization of recombinant Streptococcus mitis-derived human platelet aggregation factor.

We previously purified Streptococcus mitis-derived human platelet aggregation factor (Sm-hPAF) from the culture supernatant of S. mitis strain Nm-65, isolated from the tooth surface of a patient with Kawasaki disease. Here we produced recombinant Sm-hPAF protein (rSm-hPAF) in Escherichia coli, to determine whether rSm-hPAF conserves its platelet aggregation activity. rSm-hPAF precursor (665 amino acids) shows up to 36-56% identity with the family of cholesterol-dependent cytolysins (CDCs), and rSm-hPAF displayed potent hemolytic activity toward mammalian erythrocytes, including human erythrocytes with platelet aggregation activity. The 162-amino acid amino-terminal domain of rSm-hPAF was found in no other CDCs except lectinolysin; this domain is homologous to a portion of pneumococcal fucolectin-related protein. Interestingly, suilysin (SLY) and pneumolysin (PLY) of CDCs also exhibit substantial human platelet aggregation activity, similar to rSm-hPAF, and the platelet aggregation by rSm-hPAF, SLY, and PLY was morphologically confirmed using light and electron microscopy.

Manifestation of psychiatric behaviors in a mouse model of griseofulvin-induced hepatic porphyria.

Most patients with hepatic porphyria exhibit neuropsychiatric symptoms, including abdominal pain, peripheral neuropathy, confusion, insomnia and mental disturbances such as anxiety and depression. Although heme deficiency and accumulation of heme precursors are thought to be responsible for neuropsychiatric manifestations in patients with acute porphyria, the pathogenetic mechanisms remain poorly understood. In the present study, we observed psychiatric behaviors in mice with hepatic porphyria induced by the ingestion of a griseofulvin (GF)-containing diet over a period of 12 weeks. GF ingestion by the mice caused an accumulation of porphyrins in the feces and a decrease in heme in the liver; these effects were observed throughout the entire duration of the experiment, with maximum levels observed after circa 1 week of ingestion of this diet. In addition, the mice developed enlargement of the liver, hepatocyte injury, and cholestasis. Mice with hepatic porphyria manifested an anxiety-like behavior by the long-term treatment (over 5 weeks) in a GF-dose and duration dependent manner. The hepatic porphyria mice also manifested depression-like behaviors by the short-term treatment (3 weeks) of GF2.0, which was reversed by administration of anti-depressant, imipramine. In conclusion, this study for the first time demonstrated psychiatric manifestations in GF-induced hepatic porphyria mice. The present results suggest that model animals could be useful for elucidating the mechanisms underlying psychiatric manifestations in syndromes such as hepatic porphyria and hepatic encephalopathy that are associated with the impairment of hepatic function.

Studies of recombinant streptococcal pyrogenic exotoxin B/cysteine protease (rSPE B/SCP) in the skin of guinea pigs & the release of histamine from cultured mast cells & basophilic leukocytes.

BACKGROUND & OBJECTIVES: Streptococcal pyrogenic exotoxin B/streptococcal cysteine protease (SPE B/SCP) is considered to be one of the virulence factors of Streptococcus pyogenes (S. pyogenes) which causes serious diseases such as severe invasive infections and streptococcal toxic shock syndrome (STSS). There are no reports on the histamine releasing activity of SPE B/SCP from mast cells, although several biological activities have been studied. It is not clear whether SPE B/SCP have the superantigenic activity. We studied whether SPE B/SCP plays as a pathogenic factor in streptococcal infections and STSS through a histamine releasing activity. METHODS: Human mast cells and basophils were generated from CD34 positive cells isolated from cord blood and cultured in the presence of rIL-6, stem cell factor and/or rIL-3. The capacity of increasing capillary permeability of recombinant SPE B/SCP (rSPE B/SCP) was studied by using the skin of guinea pigs. Mitogenic activity to human T-cells of rSPE B/SCP was studied by incorporation of (3)Hthymidine. The levels of histamine in the plasma of patients with STSS and controls were measured by ELISA kit. RESULTS: rSPE B/SCP induced increased capillary permeability in the skin of guinea pigs, but both SPE A and SPE C did not exhibit such activity. Histamine was released from cultured human mast cells stimulated with rSPE B/SCP. The rSPE B/SCP did not exhibit mitogenic activity to human T-cells. Three of the 7 patients with STSS showed higher levels of plasma histamine than those of normal subjects. INTERPRETATION & CONCLUSION: The results suggested that increased capillary permeability and histamine release from mast cells induced by rSPE B/SCP might be involved in STSS and/or streptococcal infection of skin and mucous membrane.

Cysteine protease activity and histamine release from the human mast cell line HMC-1 stimulated by recombinant streptococcal pyrogenic exotoxin B/streptococcal cysteine protease.

We constructed the expression vector pSK-SCP containing the streptococcal exotoxin B gene (spe b) which expressed protease activity. We showed that the recombinant streptococcal pyogenic exotoxin B/streptococcal cysteine protease (rSPE B/SCP) was secreted into the culture supernatant of the transformant and retained its SCP activity, which was equivalent to or greater than that of the naturally occurring molecule. The secreted rSPE B/SCP induced histamine release and degranulation of the human mast cell line HMC-1. This study may contribute to the understanding of the pathogenic role of SPE B/SCP in streptococcal infection and streptococcal toxic shock syndrome.