A photosystem I reaction center driven by chlorophyll d in oxygenic photosynthesis

A far-red type of oxygenic photosynthesis was discovered in Acaryochloris marina, a recently found marine prokaryote that produces an atypical pigment chlorophyll d (Chl d). The purified photosystem I reaction center complex of A. marina contained 180 Chl d per 1 Chl a with PsaA–F, -L, -K, and two extra polypeptides. Laser excitation induced absorption changes of reaction center Chl d that was named P740 after its peak wavelength. A midpoint oxidation reduction potential of P740 was determined to be +335 mV. P740 uses light of significantly low quantum energy (740 nm = 1.68 eV) but generates a reducing power almost equivalent to that produced by a special pair of Chl a (P700) that absorbs red light at 700 nm (1.77 eV) in photosystem I of plants and cyanobacteria. The oxygenic photosynthesis based on Chl d might either be an acclimation to the far-red light environments or an evolutionary intermediate between the red-absorbing oxygenic and the far-red absorbing anoxygenic photosynthesis that uses bacteriochlorophylls.     

Transformation of myelodysplastic syndrome to acute lymphoblastic leukemia: A case report and review of the literature

Myelodysplastic syndrome (MDS) often transforms into acute leukemia, usually of a myeloid phenotype. However, the transformation of MDS into acute lymphoblastic leukemia (ALL) is extremely rare. We present a case of refractory anemia with excess of blasts (RAEB) that transformed into ALL. MDS (RAEB) was diagnosed in a 68-year-old Japanese woman in August 2001. Two months later, MDS progressed to erythroleukemia (French-American-British [FAB]classification, acute myeloid leukemia [AML]-M6), and in December, 2001, she was treated with combined chemotherapy containing aclarubicin, cytarabine, and granulocyte colony-stimulating factor, which improved her clinical symptoms. However, 1 month after the chemotherapy, she developed ALL. The blasts at that time had a markedly basophilic cytoplasm with multiple cytoplasmic vacuoles, and their morphology mimicked that of ALL-L3. The blasts also expressed CD13, a myeloid marker, in addition to lymphoid markers. Southern-blot analysis revealed rearrangement of the immunoglobulin heavy chain, but no additional chromosomal abnormality characteristic of ALL-L3 was detected. The patient was treated with chemotherapy, but she developed tumor lysis syndrome and died of multiple organ failure. Although the precise mechanism of lymphoid transformation is not yet fully understood, this case clinically supports the nature of MDS as a pluripotent hematopoietic stem cell disorder.     

Imaging and pathological features of gastric lesion of immunoglobulin G4-related disease: A case report and review of the recent literature

Abstract

We describe a 67-year-old man with immunoglobulin G4-related disease (IgG4-RD) presenting with optic neuropathy, dacryoadenitis, periaortitis, retroperitoneal fibrosis, and a gastric mass-like lesion. A mass-like lesion measuring 52?×?40?mm in the antrum of the stomach was found incidentally through whole-body screening for other organ involvement of IgG4-RD using contrast-enhanced computed tomography (CT). Histology of the stomach revealed that the lesion was also IgG4-related and was located in the submucosal layer extending to the subserosal region. This case suggests that the stomach can also be a site of involvement of IgG4-RD.     

MRI of atherosclerosis in clinical trials

Magnetic resonance imaging (MRI) of the arterial wall has emerged as a viable technology for characterizing atherosclerotic lesions in vivo, especially within carotid arteries and other large vessels. This capability has facilitated the use of carotid MRI in clinical trials to evaluate therapeutic effects on atherosclerotic lesions themselves. MRI is specifically able to characterize three important aspects of the lesion: size, composition and biological activity. Lesion size, expressed as a total wall volume, may be more sensitive than maximal vessel narrowing (stenosis) as a measure of therapeutic effects, as it reflects changes along the entire length of the lesion and accounts for vessel remodeling. Lesion composition (e.g. lipid, fibrous and calcified content) may reflect therapeutic effects that do not alter lesion size or stenosis, but cause a transition from a vulnerable plaque composition to a more stable one. Biological activity, most notably inflammation, is an emerging target for imaging that is thought to destabilize plaque and which may be a systemic marker of vulnerability. The ability of MRI to characterize each of these features in carotid atherosclerotic lesions gives it the potential, under certain circumstances, to replace traditional trials involving large numbers of subjects and hard end-points--heart attacks and strokes--with smaller, shorter trials involving imaging end-points. In this review, the state of the art in MRI of atherosclerosis is presented in terms of hardware, image acquisition protocols and post-processing. Also, the results of validation studies for measuring lesion size, composition and inflammation will be summarized. Finally, the status of several clinical trials involving MRI of atherosclerosis will be reviewed.     

An unusual case of cystic nephroma protruding into the renal pelvis

Cystic nephroma is a relatively rare and benign renal lesion of uncertain etiology. Approximately 200 cases have been described, but only a few cases of cystic nephroma with prominent renal pelvis involvement have been reported. Here, we report an unusual case of cystic nephroma that protruded into the renal pelvis. A 45-year-old woman hospitalized because of a right renal mass detected on clinical examination. The diagnosis of a malignant or benign lesion was not clear. A right nephroureterectomy was performed. The characteristics of the resected specimen were consistent with those of cystic nephroma. Macroscopic examination revealed that the giant lesion originated from the upper renal pelvis and extended into the renal pelvis. The patient is currently free from disease at eight months after the surgery. In general, this tumor arises from the renal parenchyma. To our knowledge, this is the fifth case report on cystic nephroma with prominent renal pelvis involvement.     

Case report: a case with small cell carcinoma of the bladder transformed from urothelial carcinoma

A 69 year-old woman visited our hospital with a chief complaint of macrohematuria in April 2004. She was diagnosed with bladder tumor. She underwent transurethral resection ofbladdar tumor three times and right partial ureterectomy for ureteral tumor following primary bladder carcinoma. All pathological findings demonstrated that the tumor was urothelial carcinoma (UC), G1-G2, pT1 including right ureteral tumor. In spite of intravesical instillation of BCG, recurrent invasive bladder tumor was found in June 2006. In July 2006, we performed total cystectomy and construction of ileal conduit. Surgical specimen revealed small cell carcinoma and immunohistochemical staining with NSE and synaptophysin was positive. On day 67 after operation, the patient died of multiple metastases to liver and bone.     

Locally advanced breast cancer with a good response to sequential endocrine monotherapy--a case report

An 81-year-old woman with a right breast tumor exposed through the skin surface visited our clinic in June 2004. Pathological findings of the resected tumor specimen indicated invasive ductal carcinoma of the breast,positive ER/PgR status,and negative HER 2/neu status. The enlarged right axillary lymph nodes were palpable. Ultrasonography and computed tomography revealed that the tumor invaded the chest wall without any metastasis to remote organs. On July 5, 2004, we started anastrozole treatment. Its effects were confirmed in the first month,and the treatment was continued for 8 months. Substituting anastrozole with exemestane was not effective. However, the exposed part of the tumor completely responded to tamoxifen that was administered for 2 months. The effect of tamoxifen continued until February 2006, and most of the subcutaneous part of the tumor became nonpalpable. Thus, sequential endocrine monotherapy proved useful for an elderly woman with locally advanced breast cancer.