Diffusible factors produced by cultured neural retinal cells enhance in vitro differentiation of pineal cone photoreceptors of developing quail embryos

The avian pineal is a photoreceptive organ and is believed to function as a circadian clock. Avian pineal cells are secretory rudimentary photoreceptors, and previous studies have demonstrated that there are two types of photoreceptors in developing quail pineals, one of which is rhodopsin-like immunoreactive and the other iodopsin-like immunoreactive. Much larger number of rhodopsin-like immunoreactive cells than of iodopsin-like immunoreactive cells were found in quail pineals, both in vivo and in vitro. In the present study we co-cultured pineal cells of embryonic quails with retinal cells but separated the two with a bio-membrane filter. We found that diffusible material produced by the cultured retinal cells intensely promotes the appearance of pineal iodopsin-like immunoreactive cells in vitro. This effect of retina-derived factor(s) is cell-type specific, since there is no effect on the differentiation of pineal rhodopsin-like immunoreactive cells. Retinal cell cultures had much more intensive iodopsin-promoting effect than other embryonic brain cultures such as cerebral cell cultures. The production of the retinal factor(s) seems to be developmentally regulated, since retinal cells from older embryos (E13 and older) did not have such effects. The factor(s) possibly act on pineal precursor cells by stimulating the expression of the iodopsin-like immunoreactive phenotype. Preliminary characterization of conditioned medium obtained from cultured retinal cells shows that the factor is a stable polypeptide, probably of low molecular weight. The pineal-retina culture system will provide a good experimental system to analyze the effect of extrinsic environments on cell differentiation.

Identification and characterization of XPC-binding domain of hHR23B

hHR23B was originally isolated as a component of a protein complex that specifically complements nucleotide excision repair (NER) defects of xeroderma pigmentosum group C cell extracts in vitro and was identified as one of two human homologs of the Saccharomyces cerevisiae NER gene product Rad23. Recombinant hHR23B has previously been shown to significantly stimulate the NER activity of recombinant human XPC protein (rhXPC). In this study we identify and functionally characterize the XPC-binding domain of hHR23B protein. We prepared various internal as well as terminal deletion products of hHR23B protein in a His-tagged form and examined their binding with rhXPC by using nickel-chelating Sepharose. We demonstrate that a domain covering 56 amino acids of hHR23B is required for binding to rhXPC as well as for stimulation of in vitro NER reactions. Interestingly, a small polypeptide corresponding to the XPC-binding domain is sufficient to exert stimulation of XPC NER activity. Comparison with known crystal structures and analysis with secondary structure programs provided strong indications that the binding domain has a predominantly amphipathic alpha-helical character, consistent with evidence that the affinity with XPC is based on hydrophobic interactions. Our work shows that binding to XPC alone is required and sufficient for the role of hHR23B in in vitro NER but does not rule out the possibility that the protein has additional functions in vivo.

Effects of lecithin addition in oil or water phase on the stability of emulsions made with whey proteins

The effects of lecithin addition in oil or water phase on the stability of oil-in-water emulsions made with 0.1 wt% whey protein and 10 wt% n-tetradecane at neutral and acidic pH were studied by monitoring the gravitational creaming and phase separation. The effects of lecithin addition on the interfacial behavior of beta-lactoglobulin were also studied to compare with the results of emulsion stability. At neutral pH, crude phosphatidylcholine (PC) from egg yolk or soybean increased the stability of the emulsion made with protein and lowered the interfacial tension of protein films more effectively than pure egg PC. A more remarkable effect on both the emulsion stability and the interfacial tension was found when crude PC was added in the oil phase rather than in the water phase. The purity of lecithins and the way to add them are suggested to be very important to make a stable emulsion with protein. On acidic pH (4.5 or 3.0), the increased creaming or phase separation in a whey protein-stabilized emulsion, but the lowered interfacial tension of beta-lactoglobulin films, were found upon the addition of pure or crude PC in oil or water phase. These results suggest that in acidic pH, densely packed films may be formed on a planar oil-water interface, but not on adsorbed layers around oil droplets in an emulsion.

Neurohumoral and hemodynamic mechanisms of diuresis during atrioventricular nodal reentrant tachycardia

Thirty-two consecutive patients with paroxysmal supraventricular tachycardias, with previously defined mechanisms of the tachycardias, were interviewed by noninvestigators about whether they experienced symptoms of diuresis during or at the termination of the tachycardias, to test the hypothesis that patients with AV nodal reentrant tachycardia would have a feeling of diuresis, polyuria, or both during or at the termination of the tachycardia. Twelve of the 13 patients with AV nodal reentrant tachycardia (92%), two of the 15 patients with AV reentrant tachycardia (13%), and one of the 4 patients with atrial flutter associated with 2:1 AV conduction (25%) felt diuresis during or at the termination of the tachycardias (AV nodal reentrant tachycardia vs other forms of tachycardia; P < 0.001). In 14 of the 32 patients, the right atrial pressure and plasma atrial natriuretic peptide (ANP) concentration were measured during both the tachycardias and sinus rhythm. The mean right atrial pressure during AV nodal reentrant tachycardia was significantly elevated compared to that during other forms of tachycardia (P < 0.01). The plasma ANP concentration during AV nodal reentrant tachycardia was also elevated significantly compared to that during other forms of tachycardias (P < 0.001). There were no significant differences in the cycle lengths of the tachycardias, age, left atrial dimensions, or the left ventricular ejection fraction between the AV nodal reentrant tachycardia and the other forms of tachycardia. We concluded that the feeling of diuresis during or at the termination of tachycardia was a more common symptom in patients with AV nodal reentrant tachycardia. The higher secretion of plasma ANP from the right atrium might be involved in the mechanism of this symptom.

Radiofrequency catheter ablation of an accessory pathway in dextrocardia

A 60-year-old woman with situs inversus and paroxysmal supraventricular tachycardias utilizing an AV accessory pathway underwent successful, uncomplicated RF ablation. Using biplane fluoroscopy, accessory pathway catheter ablation in dextrocardia is as safe, easy, and useful as that for normal heart structure cases, and does not require a lengthy procedure.

[A patient with bronchial asthma and mucoid impaction who presented with a high concentration of carcinoembryonic antigen in serum]

We encountered a patient with bronchial asthma and mucoid impaction who presented with a high concentration of carcinoembryonic antigen (CEA) in serum. The patient was a 46-year-old woman. One year after resection of a uterine myoma and an ovarian cyst, examination of serum revealed a high concentration of CEA (24.1 ng/ml). Further examination revealed no evidence of malignant disease, but an abnormal shadow was seen on a chest X-ray film, and was thought to be compatible with mucoid impaction. Fiberoptic bronchoscopy revealed mucoid impaction in the right lower-lobe bronchus. The concentration of CEA in bronchoalveolar lavage fluid was also high (6100 ng/ml). Lavage was done five times and the impaction was removed completely. The concentrations of CEA in serum and in bronchoalveolar lavage fluid decreased to 3.4 ng/ml and 621.9 ng/ml, respectively.

Selective cleavages of tRNAPhe with secondary and tertiary structures by enediyne antitumor antibiotics

Some enediyne antitumor antibiotics induce site-selective cleavages for yeast tRNA(Phe) with three-dimensional structure. Of special interest is the fact that tRNA(Phe) is specifically cleaved at the anticodon arm regions by C-1027 and esperamicin A1 in the presence of Mg2+ ions. Although neocarzinostatin strongly breaks tRNA(Phe) at 5'-GPu steps in the absence of magnesium ions, its cleavage ability is completely lost in the presence of 100 microM Mg2+ ions. Dynemicin A, which favors an intercalative binding, causes no strand scissions for the RNA with secondary and tertiary structures. This cutting of tRNA(Phe) may reveal that RNA as well as DNA constitutes a therapeutically relevant target for certain enediyne antitumor antibiotics.

A newly identified membrane protein localized exclusively in intracellular organelles of neurons

We report here cloning of the cDNA of a novel membrane protein, termed p24, which, of the eight mouse tissues tested, was found only in brain where it is localized exclusively in neurons. The cDNA encodes 196 amino acids with a molecular weight of approximately 24000. P24 contains two putative membrane spanning domains and a sequence in the hydrophilic tail homologous to the microtubule-binding domain of microtubule-associated proteins, such as TAU and MAP-2. We prepared antibodies to p24 and demonstrated that the protein is rich in nerve fibers of the cerebral cortex, anterior cerebral nuclei and hypothalamus. When neuroblastoma Neuro 2a cells were treated with retinoic acid to induce differentiation, p24 mRNA increased but the p24 protein was not detected. The protein expressed from the p24 cDNA in non-neuronal Cos-7 cells was 24 kDa in size and were localized only in lysosomes. These findings indicate that p24 is a neuron-specific membrane protein localized in intracellular organelles of highly differentiated neural cells and suggest that it may play a role in the neural organelle transport system.

The hydrophobic region of signal peptides is involved in the interaction with membrane-bound SecA

The positive charges of signal peptides are important for the interaction with SecA, a translocation ATPase. To examine whether or not the hydrophobic region of signal peptides also interacts with SecA, we constructed model preproteins, proOmpF-Lpps, possessing no positively charged amino acid residues at the amino-terminus and different numbers of alanine/leucine residues in the hydrophobic region of signal peptides. When the hydrophobic stretch was sufficiently long, amino-terminal positively charged residues were not required for the translocation of preproteins across the cytoplasmic membrane of Escherichia coli both in vitro and in vivo. Chemical cross-linking between SecA and preproteins possessing no positively charged residues at the amino-terminus was observed only in the presence of liposomes containing acidic phospholipids. The degree of cross-linking increased as the length of the hydrophobic stretch increased irrespective of whether positively charged residues were present or not. A preprotein possessing no positively charged residues at the amino-terminus, which is competent in the presence of liposomes, competitively inhibited the cross-linking of wild-type proOmpF-Lpp with SecA under the same conditions. It is concluded that both the amino-terminal positive charges and central hydrophobic domains are involved in the interaction with SecA in the initial stage of translocation in addition to their possible roles in transmembrane movement of preproteins.

Chronic intractable headache in a patient with Marfan's syndrome

A 30-year-old woman with Marfan's syndrome had chronic intractable headaches and spontaneous intracranial hypotension. The pain was concentrated over the occipitonuchal region, had elements of both migraine and tension headache, and was often aggravated by postural change. Myelography showed multiple, large, lumbosacral arachnoid diverticula. Radioisotope cisternography revealed a halolike accumulation in the lumbosacral region and rapid uptake of isotope in the urinary bladder, indicating cerebrospinal fluid leakage. Epidural blood patching brought immediate relief from the positional headaches. We concluded that patients with Marfan's syndrome and undifferentiated chronic headaches should be radiologically evaluated for spinal meningeal defects.

Chromosomal localization of the human arginase II gene and tissue distribution of its mRNA

Liver-type arginase (arginase I) is expressed almost exclusively in the liver and catalyzes the last step of urea synthesis, whereas the nonhepatic type (arginase II) is expressed in extrahepatic tissues and is probably involved in down-regulation of nitric oxide synthesis. We isolated cDNA for human arginase II (T. Gotoh et al., 1996, FEBS Lett. 395, 119-122). Fluorescence in situ hybridization mapping and PCR mapping studies with somatic cell hybrid panels and a radiation hybrid panel localized the arginase II gene to chromosome 14q24.1-24.3. Dot-blot analysis showed that arginase II mRNA is expressed strongly in the adult human kidney and weakly in the prostate, pituitary gland, lung, liver, thyroid gland, and small intestine. The mRNA was either at very low levels or not detectable in the fetal kidney, lung, and liver. Thus, expression of the human arginase II gene is regulated both tissue-specifically and developmentally.

The role of E-selectin for neutrophil activation and tumor metastasis in vivo

The selectin class of adhesion molecules plays a critical role in facilitating leukocyte adhesion to and subsequent transmigration of endothelium. On this basis, selectins have been suggested to promote metastasis of certain types of tumors, although direct evidence is lacking. To explore this hypothesis two sets of transgenic mice were developed, one TgNES, which constitutively expresses cell surface E-selectin in all tissues, the other TgNEsol, which expresses truncated, soluble E-selectin in the liver. Both transgenic mice showed apparently normal phenotype. However in TgNES mice, but not in TgNEsol mice, the number of neutrophil decreased to 50% compared with that in their negative littermate. And also these neutrophils were markedly activated. On the other hand, B16 F10 melanoma cells were stably transfected with alpha 1-3/4 fucosyltransferase-specific cDNA (B16F10 ft), allowing them to express E-selectin ligands. Normal mice injected with B16F10 ft developed lung tumors exclusively. In contrast, TgNES mice developed massive, infiltrating liver tumors. TgNEsol mice also developed liver tumors that grow more slowly. These observations suggest the important role of E-selectin for neutrophil activation and tumor metastasis in vivo.

Targeted integration of DNA using mutant lox sites in embryonic stem cells

Site-directed DNA integration has been achieved by using a pair of mutant lox sites, a right element (RE) mutant lox site and a left element (LE) mutant lox site [Albertet al. (1995)Plant J., 7, 649-659], in mouse embryonic stem (ES) cells. We established ES cell lines carrying a single copy of the wild-type lox Por LE mutant lox site as a target and examined the frequency of site-specific integration of a targeting vector carrying a loxP or RE mutant lox site induced by Cre transient expression. Since our targeting vector contains a complete neo gene, random integrants can form colonies as in the case of a gene targeting event through homologous recombination. With our system, the frequency of site-specific integration via the mutant lox sites reached a maximum of 16%. In contrast, the wild-type loxP sites yielded very low frequencies (<0.5%) of site-specific integration events. This mutatedloxsystem will be useful for 'knock-in' integration of DNA in ES cells.

Blood flow in common carotid and vertebral arteries in patients with sudden deafness

Blood flow was measured in the common carotid artery (CCA) and the vertebral artery (VA) by the ultrasonic Doppler method in 14 male patients with sudden deafness and 70 normal adults. In the patients, blood flow on the affected side was slower than that on the normal side or that of the control group. Although these differences were not statistically significant in the CCA or in the VA, significant differences in the blood flow were noted between the group with a hearing loss of greater than 50 dB and the group with a loss of less than 50 dB. A negative correlation was found between blood viscosity and blood flow in both CCAs and both VAs. After stellate ganglion block (SGB), the blood flow of the CCA and VA increased on the side of the SGB and decreased on the opposite side. The changes in blood flow after SGB decreased with age, presumably because of changes in the blood vessel walls and a weaker response to sympathetic nerve receptors in the arterial wall.

Effects of volatile anesthetics on the calcium ionophore A23187-mediated alterations in hepatic flow and metabolism in the perfused liver in fasted rats

Alterations in intracellular calcium homeostasis have been implicated in heptic injury. Volatile anesthetics modulate the homeostasis of intracellular calcium. The effects of volatile anesthetics on the hemodynamic and metabolic alterations induced by the calcium ionophore A23187 were studied using isolated liver perfusion in fasted rats. The liver was isolated from 24 hr-fasted male Sprague-Dawley rats, and perfused through the portal vein at a constant pressure of 1.2 kPa in a recirculating perfusion-aeration system. Halothane, isoflurane and sevoflurane were administered at 2%, 3% and 4.4%, respectively. All volatile anesthetics maintained basal hepatic flow, reduced oxygen consumption, and transiently enhanced net lactate production. A23187 at initial concentrations of 0.8 to 3.2 microM decreased hepatic flow and oxygen consumption in a dose-dependent manner, and enhanced lactate production. All anesthetics significantly attenuated the decreases in hepatic flow and oxygen consumption after administration of A23187 at 1.6 microM. None of the anesthetics significantly influenced the A23187-induced enhancement of net lactate production. Volatile anesthetics may attenuate the hepatic vasoconstriction and oxygen debt induced by intracellular calcium overload.

Paired pineals in the developing quail (Coturnix coturnix japonica) embryos

Paired pineals were observed as an anomaly in embryonic quail brains between 7 and 9 days of incubation. The size of each pineal was almost the same as that of the normal pineal and it was located slightly lateral of the midline. Histological examination of these paired pineals revealed that both had similar cytological features in comparison with the normal pineal of the same developmental stage. No abnormal features were detected in brains and eyes of the embryos with paired pineals. Since the presumptive pineal rudiments are considered to exist in the neural folds and to fuse in the midline during the formation of the neural tube, the paired pineals may be interpreted as a result of incomplete fusion of the pineal anlagen. This report describes for the first time the symmetrical occurrence of pineal glands in the developing avian brain.

E-selectin binding promotes neutrophil activation in vivo in E-selectin transgenic mice

E-selectin is a membrane protein expressed by endothelial cells activated by cytokines released during the inflammatory process; it plays an important role in neutrophil emigration into inflamed tissues. To further explore in vivo the function of E-selectin, we have generated transgenic mouse line expressing E-selectin under the control of a chicken beta-actin promoter. In these mice, the number of blood neutrophils was reduced, without any other obvious phenotype or tissue damage. These neutrophils, however, displayed two significant changes: first, an alteration in the levels of expression of two membrane receptors involved in neutrophil adhesion to endothelial cells, namely a marked increased in the Mac-1 antigen (CD11b/CD18) and a decrease in the Mel-14 antigen (L-selectin); second, an increased oxidative activity when compared to blood neutrophils of non-transgenic mice, as shown by their capacity to oxidize 2',7'-dichlorofluorescein (DCFH) into a fluorescent compound. These observations indicate that the binding of E-selection with neutrophils bearing its ligands promotes neutrophil activation in vivo.

[The production of high sensitive anti-myeloperoxidase monoclonal antibodies and their sensitivity and specificity]

We produced anti-myeloperoxidase(MPO) monoclonal antibodies(moAb) to detect MPO sensitivity in leukemic cells by visual light microscopy. We got seven kinds of moAbs which showed different properties to MPO. These antibodies reacted to MPO in immature and mature neutrophils, monocytes and HL-60(human myeloid leukemic cell line) by immunochemical detection using the avidin-biotin complex(ABC) staining method, but the amounts of immune complex products were significantly different at each moAb. MPO2, MPO4, MPO9 and MPO13 moAbs blocked MPO activities but MPO5 showed no such inhibition. Most of the moAbs reacted to 59kD MPO moAb using the western blotting method, while MPO4 and MPO5 reacted to both 81kD and 89kD MPO precursors. This data suggests that these moAbs are useful to demonstrate a small amount of MPO in leukemic cells.

Preparation and characterization of monoclonal antibodies specific for lauroylated isoform of bovine transducin alpha-subunit: immunohistochemical analysis of bovine retinas

The photoreceptor G protein transducin [alpha- and beta gamma-subunits (T alpha/T beta gamma)] plays a central role in the visual transduction process. The amino-terminus of bovine T alpha is modified by one of four distinct fatty acids-laurate (C12:0), myristate (C14:0), C14:1 (5-cis), and C14:2 (5-cis, 8-cis)-but the biological significance and the localization of the four isoforms of T alpha are poorly understood. To investigate the cellular distribution of each isoform, we prepared monoclonal antibodies against a synthetic C12:0-, C14:0-, C14:1-, or C14:2-nonapeptide corresponding to the N-terminal region of T alpha. Among several types of antibodies isolated, only one type, represented by LA4, reacted specifically with the C12:0-peptide as well as purified T alpha but not with the other proteins in bovine retinal homogenate, including recoverin, indicating that the epitope comprises both C12:0 and the N-terminal amino acids of T alpha. Immunohistochemical analyses of bovine retinal sections by LA4 showed the uniform distribution of C12:0-T alpha in almost all the rod outer segments. Hence, it seemed unlikely that each isoform of T alpha was localized in specific cells. This observation, together with evidence for a possible functional diversity among the isoforms, suggests that the four isoforms of T alpha in a single rod cell may contribute simultaneously to a fine tuning of the photon-signal transduction process.

Primary diaphragmatic schwannoma with a typical target appearance: correlation of CT and MR imagings and histologic findings

A rare case of benign diaphragmatic schwannoma in a 38-year-old female is reported. Precontrast computed tomography (CT) showed an encapsulated well-defined round homogeneous tumor with central calcification, measuring approximately 5 cm in diameter, arising from the left diaphragm. Contrast-enhanced CT and gadolinium-enhanced T1-weighted magnetic resonance (MR) imaging showed focal enhancement in the central portion of the tumor. The tumor showed a typical target appearance of increased peripheral signal intensity and decreased central signal intensity on unenhanced T2-weighted images. Pathological examination of resected specimens of the tumor showed two zonal histological components: a hypercellular portion of spindle cells with nuclear palisading (Antoni A tissue) and a hypocellular portion of cells with cystic degeneration, together with focal calcification and hemangeomatous vascular changes (Antoni B tissue). We consider the radiological characteristics of diaphragmatic schwannoma on CT and MR imagings to represent the geographic difference between the histologic zones of the tumor.

Redirection of tumor metastasis by expression of E-selectin in vivo

The selectin class of adhesion molecules plays a critical role in facilitating leukocyte adhesion to and subsequent transmigration of endothelium. On this basis, selectins have been suggested to promote tumor cell attachment to endothelium, thereby facilitating metastasis of certain types of tumors, although direct evidence for such a role is lacking. To explore this hypothesis, two sets of transgenic mice were developed: TgnES, which constitutively expresses cell surface E-selectin in all tissues, under the control of the beta-actin promoter; and TgnEsol, which expresses truncated, soluble E-selectin in the liver, under the control of the alpha 1 antitrypsin promoter. B16F10 melanoma cells were stably transfected with alpha(1,3/1,4) fucosyltransferase-specific cDNA (B16F10ft), allowing them to express E-selectin ligands or with hygromycin resistance selection vector only B16F10hygro). Normal mice injected with B16F10ft and B16F10hygro and transgenic mice injected with B16F10hygro developed lung tumors exclusively. In contrast, TgnES mice injected with B16F10ft cells developed massive infiltrating liver tumors. B16F10ft cells injected into TgnEsol mice also formed liver tumors, but these grew more slowly, with a well-delineated, noninfiltrating distinct histologic pattern. These observations provide direct evidence that expression of E-selectin can redirect metastasis of tumor cells expressing appropriate ligands in vivo.

Follicular development and ovulation in macrophage colony-stimulating factor-deficient mice homozygous for the osteopetrosis (op) mutation

To clarify the role of macrophages and macrophage colony-stimulating factor (M-CSF) in follicular development and ovulation, the processes of folliculogenesis and ovulation, numerical changes in macrophages, and proliferative capacity of granulosa cells were examined in op/op mice before or after daily M-CSF administration. The natural estrous cycle was determined daily by means of vaginal smears. The number of ovulated ova in both fallopian tubes was significantly smaller in op/op mice than in normal littermates. Such ova markedly increased in number after daily M-CSF administration. The numbers of both antral and mature follicles in the proestrous ovary were markedly lower in op/op mice than in the controls and increased after daily M-CSF administration. Flash-labeling with [3H]thymidine showed that the proliferative capacity of granulosa cells in antral follicles was reduced in op/op mice but elevated after daily M-CSF administration. Numbers of granulosa cells and macrophages in the antral follicles were significantly decreased in op/op mice but were increased after M-CSF treatment. All these data provide evidence that macrophages are implicated in the process of folliculogenesis and ovulation.

Dermatoscopic and videomicroscopic features of melanocytic plantar nevi

Nearly 10% of Japanese people have pigmented nevi on the soles. Since malignant melanoma also occurs on the plantar area in the Japanese, it would be very valuable to be able to differentiate benign and malignant lesions in the early clinical state. We have investigated the epiluminescence microscopic features of 500 melanocytic nevi on the soles of Japanese people using a dermatoscope and a videomicroscope that can magnify lesions from x 10 to x 200. The results showed that the surface profile of benign melanocytic nevi is mainly classified into five types; that 9% of plantar nevi, however, do not fit into this classification and are categorized as a miscellaneous type; and that the other nonmelanocytic disorders, such as verruca vulgaris and black heel, are easily differentiated by their surface profile. More important, the histological examination showed that atypical nevi, malignant melanoma in situ, and acral lentiginous melanoma are exclusively compartmentalized in the miscellaneous type of surface profile. Our data suggested that epiluminescence microscopy may be a useful method for discrimination of plantar benign and malignant melanocytic lesions.