Surgical treatment for ischemic mitral regurgitation: strategy for a tethered valve.

Recently, ischemic mitral regurgitation (IMR) has been shown to be an individual risk factor for ischemic heart disease. The main mechanism of IMR is tethering of the leaflet secondary to left ventricular (LV) dilatation. In this situation, surgical treatment for IMR has been limited to ring annuloplasty with varying degrees of effectiveness. However, mid-term follow-up studies have shown that the results obtained with this approach are not satisfactory. Therefore, there has been a need to develop additional techniques to achieve more secure repair of IMR. The characteristics of the mitral leaflet configuration in IMR are apical displacement of the leaflets relative to the annulus, concavity of the leaflets, and a dilated annulus. Our basic strategy for a tethered mitral valve is rigid ring annuloplasty and inward correction of the outwardly displaced papillary muscle. For the latter correction, we employ the overlapping method or septal anterior ventricular exclusion (SAVE) procedure for LV volume reduction in cases of broad antero-septal infarction, or elevate the posterior papillary muscle by folding the LV wall at the root of the posterior papillary muscle via a small incision in the inferior wall in cases of infero-posterior infarction. An additional procedure is chordal cutting in combination with rigid ring annuloplasty and papillary muscle imbrication in combination with LV volume reduction. We have successfully combined these methods with the aid of detailed echocardiographic studies in individual patients. However, long-term follow-up will be necessary before this approach can be routinely adopted.     

A Combination of Speckled Lentiginous Nevus with Patch-type Blue Nevus

A peculiar case of “nevus on nevus” was reported. A 67-year-old man had had a pigmented lesion in the left hypochondrial area since birth. The clinicopathologic findings of the pigmented lesion revealed a combination of speckled lentiginous nevus and patch-type blue nevus. This case of “nevus on nevus” is not described under the term of combined nevus as is current in the literature; it was considered to be a subtype of the type II atypical blue nevus described by Kawamura.     

ULTRASTRUCTURE OF AN ANAPLASTIC GIANT-CELL CARCINOMA FOUND 8 YEARS AFTER OPERATION ON A PAPILLARY CARCINOMA OF THE THYROID

Light and electron microscopic studies have been made on an anaplastic giant-cell tumor that developed in a woman 8 years after an operation on the thyroid for papillary carcinoma. Many giant cells were observed in the anaplastic tumor tissue, but no follicles. Numerous tightly-packed mitochondria and abundant ribosomes were present, but there were no desmosomes. The basement membrane was not distinct.     

Isolation of vaccine-derived type 1 polioviruses displaying similar properties to virulent wild strain Mahoney from sewage in Japan

Type 1, 2, and 3 vaccine-derived polioviruses were isolated from a sewage disposal plant located downstream of the Oyabe River in Toyama Prefecture, Japan, between October 1993 and September 1995. Neurovirulence was analyzed in 13 type 1 vaccine-derived strains, using mutant analysis by polymerase chain reaction and restriction enzyme cleavage (MAPREC). Nine strains (69%) were estimated to have marked neurovirulence. Some of the neutralizing antigenic sites, temperature sensitivity, and plaque-forming ability of two virulent vaccine-derived poliovirus strains were similar to Mahoney strain. The neutralizing activity of human sera obtained after oral poliomyelitis vaccine (OPV) administration against one of the virulent vaccine-derived polioviruses was examined. Although all human sera showed sufficient neutralizing activity for the prevention of poliomyelitis by vaccine-derived poliovirus strains, a lower titer than that against Sabin type 1 strain was observed. Vaccination against virulent vaccine-derived poliovirus will be effective. However, the environmental presence of viruses that have properties similar to those Mahoney strain is a threat. The introduction of inactivated poliovirus vaccine (IPV), and well-maintained herd immunity, together with reinforced environmental surveillance is important for the final phase of the polio eradication program by the World Health Organization (WHO).     

The effect of acetylcholine on chloride transport across the mouse lacrimal gland acinar cell membranes

The mechanisms of Cl^– transport and the effects of acetylcholine (ACh) and electrochemical Cl^– potential changes across the basolateral plasma membrane on intracellular Cl^– activity in the acinar cells of isolated mouse lacrimal glands were studied using double-barreled Cl^–-selective microelectrodes. In the resting state, the basolateral membrane potential (V _m) was about –40 mV and intracellular Cl^– activity was about 35 mmol/l. Addition of ACh (10^–910^–6 mol/l) hyperpolarizedV _m and decreased the Cl^– activity in a dose-dependent manner. ACh (10^–6 mol/l) hyperpolarizedV _m by 20 mV and decreased the cytosolic Cl^– activity with an initial rate of 16.0 mmol/l · min. Reduction of the perfusate Cl^– concentration to 1/9 control depolarizedV _m and decreased cytosolic Cl^– activity at a rate of 1.9 mmol/l · min. AV _m hyperpolarization of 20 mV produced by DC injection to the adjacent cell decreased Cl^– activity at a rate of 4.6 mmol/l · min. DIDS (1 mmol/l) hyperpolarizedV _m by 8 mV with little change in Cl^– activity and increased the input resistance of the cells by 25%. DIDS decreased the rate of change in Cl^– activity induced by low-Cl^– Ringer to 35% of control, but had no effect on the ACh-evoked decrease in the Cl^– activity. Furosemide (1 mmol/l) slightly hyperpolarizedV _m and decreased Cl^– activity at a slow rate but affected Cl^– movements induced by ACh or low-Cl^– Ringer only slightly. Cl^– uptake into the cells was inhibited partially by furosemide. The present results showed that ACh induces an increase in the Cl^– permeability across the luminal plasma membrane and that the basolateral membrane possesses a DIDS-sensitive Cl^– conductance pathway and a furosemide-sensitive Cl^– uptake mechanism.     

Surface ultrastructure of prestomal teeth of some flies in the families Calliphoridae, Muscidae and Sarcophagidae

Prestomal teeth of flies in the families Calliphoridae (Chrysomya pinguis, Chrysomya villeneuvi, and Chrysomya chani), Muscidae (Hydrotaea (= Ophyra) chalcogaster) and Sarcophagidae (Boettcherisca peregrina) were presented using scanning electron microscopy. The slight to deep bifurcation of the tips of their teeth were similarly observed in all species examined. The anatomical feature of prestomal teeth of the flies examined may contribute to the understanding of their feeding behavior and the medical importance of their role in the future.     

Scintigraphic demonstration of renal cell carcinoma with I-131-6β-iodomethyl-19-norcholesterol: A case report

Extraadrenal abnormal uptake on adrenocortical scintigraphy has been reported rarely in the normal gallbladder, lipid cell tumor of the ovary, or in clear cell type renal cell carcinoma. Clear cell type renal cell carcinoma contains glycogen and cholesterol like the adrenal gland, but the uptake of the radionuclide I-131 cholesterol has been reported to be low and not sufficient to image it. Right renal and adrenal masses were incidentally discovered on abdominal CT scan in a patient with chronic renal failure resulting in bilateral acquired cystic kidney disease. Adrenocortical scintigraphy done to know the nature of the adrenal mass showed high uptake corresponding to the right renal mass and the right adrenal mass. Clear cell type renal cell carcinoma and adrenal adenoma with prominent clear cells were histologically confirmed on hematoxylin-eosin stain and in an immunohistochemical study with renal cell antibody. Not only low-density lipoprotein receptors mediated uptake but also overall replacement of the right non-tumorous renal parenchyma by acquired cysts may have played a role in imaging the renal cell carcinoma on adrenocortical scintigraphy.     

Some observations in the fine structure of age changes of the mouse retinal pigment epithelium

Summary Age changes of the fine structure in the CF-1 mouse retinal pigment epithelium were studied from 1–24 months old. The change most characteristic of the senescence of the retinal pigment epithelium was found to be the appearance of wavy undulating 12 nm wide filaments having a periodicity of about 80 nm after the 12th month. In addition, the retinal pigment epithelial cells of the aging eye were found to have a marked accumulation of lysosomal dense bodies measuring about 0.3 to 1.2 m in diameter especially in the apical portion of the cytoplasm. Extended and enlarged basal cytoplasmic infoldings of the retinal pigment epithelial cells were another prominent age change in the old mouse. In these basal infoldings densely fixed amorphous materials by tannic acid and very fine filaments are recognized. Age-related changes of the retinal pigment epithelial cell of the CF-1 mouse may take place as the degeneration of cytoplasmic materials, the appearance of bundles consisting of parallel undulating filaments, and the extending process of basal infolding from the choroid side.     

Three-dimensional analysis of benign paroxysmal positional nystagmus in a patient with anterior semicircular canal variant.

OBJECTIVE: To show the positional nystagmus in a patient who had suffered from benign paroxysmal positional vertigo (BPPV) that was thought to be caused by involvement of the anterior semicircular canal (ASCC) (A-BPPV). STUDY DESIGN: Retrospective case report. SETTING: City hospital. PATIENT: The present study reports a rare case of A-BPPV in a 41-year-old woman. CASE REPORT: The patient is 41-year-old woman who developed a positional vertigo after playing volleyball on March 22, 2005 and consulted our hospital the next day. When left Dix-Hallpike maneuver was performed, she showed a positional nystagmus of which fast phase direction of the torsional component was clockwise while that of the vertical component was downward. We plotted the slow phase eye velocity of the positional nystagmus during the left Dix-Hallpike maneuver on three-dimensional coordinates that showed the axis of the positional nystagmus to be perpendicular to the plane of the right ASCC. CONCLUSION: These results suggested that the patient was suffering from A-BPPV.