Search PubMed⌕ Search

Biomedical subjects

A Tamai

Publications and source records attributed to A Tamai.

At least 19 recordsLinked to original sources
PubMed2001

Management of posterior capsule rupture during phacoemulsification using the dry technique.

To manage posterior capsule rupture during phacoemulsification, we use a dry technique in which all procedures are performed without an irrigation/aspiration system. The dry technique is characterized by (1) continuous viscoelastic injection instead of fluid irrigation to maintain anterior chamber depth with the posterior capsule and vitreous located posteriorly and (2) static removal of most residual lens material by viscoexpression and/or manual small incision extracapsular cataract extraction without aspiration and dynamic water flow. In 16 cases of posterior capsule rupture managed using the dry technique, the residual nucleus and cortex were readily removed with minimum extension of the ruptured area and new vitreous loss. Although large amounts of viscoelastic material (mean 5.8 mL) were required, rapid and stable visual recovery was comparable to that in patients having uneventful surgery. The dry system is a safe and reliable technique for managing posterior capsule rupture during phacoemulsification.

Eye Injuries↗
PubMed2001

Cell-to-cell movement of Potato virus X: the role of p12 and p8 encoded by the second and third open reading frames of the triple gene block.

Potato virus X (PVX) requires three proteins, p25, p12, and p8, encoded by the triple gene block plus the coat protein (CP) for cell-to-cell movement. When each of these proteins was co-expressed with a cytosolic green fluorescent protein (GFP) in the epidermal cells of Nicotiana benthamiana by the microprojectile bombardment-mediated gene delivery method, only p12 enhanced diffusion of co-expressed GFP, indicating an ability to alter plasmodesmal permeability. p25, p12, and CP, expressed transiently in the initially infected cells, transcomplemented the corresponding movement-defective mutants to spread through two or more cell boundaries. Thus, these proteins probably move from cell to cell with the genomic RNA. In contrast, p8 only functioned intracellularly and was not absolutely required for cell-to-cell movement. Since overexpression of p12 overcame the p8 deficiency, p8 appears to facilitate the functioning of p12, presumably by mediating its intracellular trafficking. Considering the likelihood that p12 and p8 are membrane proteins, it is suggested that intercellular as well as intracellular movement of PVX involves a membrane-mediated process.

Biolistics↗
PubMed2001

Tobamoviral movement protein transiently expressed in a single epidermal cell functions beyond multiple plasmodesmata and spreads multicellularly in an infection-coupled manner.

Cell-to-cell movement of a plant virus requires expression of the movement protein (MP). It has not been fully elucidated, however, how the MP functions in primary infected cells. With the use of a microprojectile bombardment-mediated DNA infection system for Tomato mosaic virus (ToMV), we found that the cotransfected ToMV MP gene exerts its effects in the initially infected cells and in their surrounding cells to achieve multicellular spread of movement-defective ToMV. Five other tobamoviral MPs examined also transcomplemented the movement-defective phenotype of ToMV, but the Cucumber mosaic virus 3a MP did not. Together with the cell-to-cell movement of the mutant virus, a fusion between the MP and an enhanced green fluorescent protein variant (EGFP) expressed in trans was distributed multicellularly and localized primarily in plasmodesmata between infected cells. In contrast, in noninfected sites the MP-EGFP fusion accumulated predominantly inside the bombarded cells as irregularly shaped aggregates, and only a minute amount of the fusion was found in plasmodesmata. Thus, the behavior of ToMV MP is greatly modulated in the presence of a replicating virus and it is highly likely that the MP spreads in the infection sites, coordinating with the cell-to-cell movement of the viral genome.

Amino Acid Sequence↗
PubMed2001

Guided knives.

A new type of knife that enables a surgeon to easily create tunnel-shaped incisions with a prescribed depth has been developed. The knife features an incision guide, the arm of which extends just beyond the tip of the blade. The space between the blade and the arm can be set at the desired width. By moving the knife as if sliding the arm across the corneal or scleral surface, the blade can move to a certain depth from the surface. The guided knife enables even novice surgeons to easily make a self-sealing incision during cataract surgery. In addition, the innovative nature of this device seems to be applicable to many other surgeries that require a partial-thickness incision.

Animals↗
PubMed2000

AHM1, a novel type of nuclear matrix-localized, MAR binding protein with a single AT hook and a J domain-homologous region.

Interactions between the nuclear matrix and special regions of chromosomal DNA called matrix attachment regions (MARs) have been implicated in various nuclear functions. We have identified a novel protein from wheat, AT hook-containing MAR binding protein1 (AHM1), that binds preferentially to MARs. A multidomain protein, AHM1 has the special combination of a J domain-homologous region and a Zn finger-like motif (a J-Z array) and an AT hook. For MAR binding, the AT hook at the C terminus was essential, and an internal portion containing the Zn finger-like motif was additionally required in vivo. AHM1 was found in the nuclear matrix fraction and was localized in the nucleoplasm. AHM1 fused to green fluorescent protein had a speckled distribution pattern inside the nucleus. AHM1 is most likely a nuclear matrix component that functions between intranuclear framework and MARs. J-Z arrays can be found in a group of (hypothetical) proteins in plants, which may share some functions, presumably to recruit specific Hsp70 partners as co-chaperones.

Amino Acid Sequence↗
PubMed1996

Correction of stress urinary incontinence: laparoscopy combined with vaginal suturing.

The authors review the published techniques of laparoscopic colposuspension combined with vaginal suturing. Particular emphasis is given to their own technique, first published in 1992, and to that of Harewood (1993), which is similar. Both involve a Burch-like colposuspension using a technique similar to that of Gittes and Loughlin. This is possible looking inside the pelvis through a laparoscope and using a handle-needle. Published results are similar (about 70% success rate), but the authors point out that the Breda technique is simpler, cheaper, and less time consuming (only one trocar instead of three) and has had a longer follow-up (up to 3 years instead of 19 months). The authors review many other similar techniques reported between 1993 and 1995 with good results but based on rather limited experience. The conclusion is that the laparoscopic technique with vaginal suturing seems a promising way to approach stress urinary incontinence in the female patient.

Female↗
PubMed1996

[Laparoscopic surgery of stress urinary incontinence in women].

The Authors carried out a literature review on stress urinary incontinence (SUI) treatment using laparoscopy or pelvioscopy. They report their experiences in using a pubo-vaginal percutaneous colposuspension assisted by pelvioscopy. Of 22 treated patients, there was a total correction of the incontinence in 15 patients. (68.12%) with a median follow-up of 18.6 months. They report also their first experience with the Retzius plasty of Manhes by laparoscopy (3/4 patients treated are continent, 1/4 has recurrent SUI during times of stress). They conclude that laparoscopy and pelvioscopy treatment can be valid alternatives to traditional surgery if made on selected patients.

Female↗
PubMed1995

Myxoma of the conjunctiva: a case report and a review of the literature.

A rare case of conjunctival myxoma is reported. A painless tumor was noted in the left bulbar conjunctiva of an 80-year-old woman. The extirpated tumor, 12 x 10 mm, was hypocellular and composed of spindle-shaped or stellate tumor cells. The tumor stroma showed extensive myxomatous changes. Alcian blue stain with hyaluronidase digestion revealed that the matrix contained rich amounts of hyaluronidase-sensitive acid mucopolysaccharides. Immunohistochemically, the tumor cells were positive for vimentin and alpha-smooth muscle actin, suggesting a fibroblastic or myofibroblastic cell phenotype. A review of the literature revealed the rare incidence and invariable benign behavior of conjunctival myxoma.

Actins↗
PubMed1995

Histopathological study of microspherophakia in the Weill-Marchesani syndrome.

A surgically obtained lens from a 66-year-old man with the Weill-Marchesani syndrome was examined histopathologically by light microscopy, transmission electron microscopy and scanning electron microscopy. The lens was diffusely opaque and brown. It was microspherophakic in appearance, 6.0 mm in equatorial diameter and 4.8 mm in anteroposterior diameter. The lens fibers were well preserved, and ran circularly in the cortex and elliptically in the fetal nucleus. The lens fibers had undergone hyaloid degeneration in the area from the deep cortex to the superficial portion of the adult nucleus. Hyaloid degeneration also extended from the anterior to the posterior pole and was more marked in the equator. The distribution of lens fibers suggested that microspherophakia had developed postnatally. It is surmised that later changes in the shape of the lens affected the lens fibers, inducing hyaloid degeneration.

Abnormalities, Multiple↗
PubMed1995

Fast oscillations of the electro-oculogram in a series of normal subjects.

Using a newly devised automated electro-oculograph, Nidek EOG-2, the fast oscillations (FOs) of the electro-oculogram were recorded in the 120 eyes of 60 normal subjects. We evaluated the normal means and variability of FO parameters, namely the "Rf" value, which is the average ratio in percentage of the maximum amplitude in the dark period (AD)/the minimum amplitude in the light period (AL), and the "df" value, which is the average difference between AD and AL during the FO measurement. No correlation with age was noted in the "Rf" value, although the lowest mean value of the "df" was detected in the twenties. Regarding sex, the mean levels of the "Rf" and "df" for female subjects were statistically higher than those for male subjects in the younger and global age groups. Some hormonal factor which can stimulate the metabolic activity of the retinal pigment epithelium might have caused this sexual difference.

Adult↗
PubMed1994

Stage A1 prostate cancer: follow-up with digital rectal exploration, prostate markers, fine-needle aspiration, ultrasonographically guided needle biopsy and biopsies of the residual prostate with resectoscope.

From January 1985 to December 1990, we performed 921 TURP and 23 retropubic adenomectomies. In 70 patients (7.4%) histological examination revealed an incidental carcinoma of the prostate (stage A), 51 of which (72.8%) were A1 and 19 (27.2%) stage A2. In our classification A1 covers cases with < 3 G1 focal lesions [Boxer, 1977]. Thirteen of the A2 cases underwent radical prostatectomy: 1 pT1G1-2, 9 pT2G1-2, 3 pT3G2 (TNM 1978); the remaining 6 were given palliative treatment. The 51 stage A1 patients were recalled for follow-up evaluation, only 20 came for checking. They were reassessed by means of DRE, markers, prostate cytologic aspiration, echo-guided transperineal needle biopsy and resection of the prostatic cavity. Our experience seems to suggest that, if we define A1 as < 3 G1 chips or less, this stage is to be considered an incidental illness that seems not to require further treatment, but only a policy of surveillance with yearly markers, DRE and echo-guided needle biopsy.

Aged↗
PubMed1994

Synaptic inputs from superior colliculus to vertical eye movement motoneurons in the cat.

The superior colliculus (SC) plays an important role in the transformation of visual and auditory signals into motor commands to generate saccadic eye movements toward the targets. This study investigated the synaptic input patterns from the SC, into vertical eye movement-related superior and inferior rectus motoneurons, using intracellular recording and SC stimulating techniques in anesthetized adult cats. It was found that the responses obtained from these motoneurons consisted of complex components: a sequence of monosynaptic excitatory postsynaptic potentials (EPSPs), di- or trisynaptic EPSPs or inhibitory postsynaptic potentials (IPSPs) and polysynaptic EPSPs. The amplitudes of the latter two components almost coincided with the motor map of the SC, which represented the correlation between the sites of SC stimulation and the directions and amplitudes of evoked saccades. It was concluded that the SC elicits vertical eye movements through these di- or trisynaptic and polysynaptic pathways in the cat.

Animals↗
PubMed1994

Time-course of lens opacity and morphological changes in rabbit lens epithelial cells after intravitreal silicone oil injection.

The clinical course of lens opacity and the morphological changes in lens epithelial cells after intravitreal silicone oil injection were observed for 3 months in 21 normal adult albino rabbits. After the simple vitrectomy in both eyes of each rabbit, silicone oil was injected into the vitreous in one eye and the other eye was kept as the control. By photoslit-lamp microscopy, 8 of the 14 examined eyes showed early posterior subcapsular lens opacity one month after silicone oil injection. By transmission electron microscopy, intracellular vesicles near the interdigitation of the lens epithelial cells were observed in all of the 7 eyes examined histologically 2 weeks after the procedure. These changes were not observed in the 7 fellow control eyes. As a result, it is surmised that cataract formation after intravitreal silicone oil injection may be associated with morphological changes in the lens epithelial cells.

Animals↗
PubMed1994

[Firing patterns of the pontine omnipause neurons during sleep in the cat].

The omnipause neurons (OPNs), located in the nuculeus raphe pontis, cease firing during all rapid eye movements and otherwise fire at a steady rate in the awake state. Firing patterns of the OPNs were studied during the awake state, non-REM sleep, and REM sleep in chronically prepared adult cats, to examine whether the OPNs' firing participates in the genesis of eye movements during each state. During non-REM sleep, the OPNs continued their firing, and their firing patterns had little correlation with slow drifting eye movements appearing in this state. During REM sleep, the OPNs maintained a tonic firing and ceased their firing during rapid eye movements in all directions. These results suggest that cessation of OPN firing plays an important role in the generation of rapid eye movements during REM sleep as well as during the awake state in the cat.

Action Potentials↗
PubMed1993

Laparoscopic nephrectomy with vaginal delivery of the intact kidney.

The first case of laparoscopic nephrectomy in Italy is described. The patient was a 51-year-old woman with a small, nonfunctional, tuberculous left kidney. The organ, once detached from its lumbar site, was brought in to the pelvic cavity and extracted from the body via a posterior colpotomy. In this way, the integrity of the organ is preserved, hence, this could be the preferable route when dealing with a little kidney tumor in a woman.

Female↗
PubMed1992

Treatment of hydrocele: randomised prospective study of simple aspiration and sclerotherapy with tetracycline.

Following reports in the literature on the efficacy of tetracycline sclerotherapy in the treatment of hydroceles, we carried out a randomised prospective study of 45 patients (50 hydroceles), comparing simple evacuation with tetracycline sclerotherapy. The results revealed no statistically significant difference in the percentage of success between the 2 groups, but complications were more common in the patients treated with tetracycline. The good results reported by other authors in non-randomised studies are, therefore, not confirmed.

Adolescent↗
PubMed1992

[Effect of GABA antagonists on the rat electroretinogram].

It has been shown that gamma-aminobutyric acid (GABA) is densely packed in the inner nuclear and plexiform layers in the rat retina, where it is mainly located within a subgroup of amacrine cells. This study examined the effects on the electroretinogram of GABA antagonists infused into the vitreous cavity of urethan-anesthetized rats. Infusions of the GABAA antagonist, bicuculline (0.1-10 mM, 3 microliters) significantly enhanced the b-wave amplitude and reduced the oscillatory potentials (OPs). Similar effects were also produced by infusions of the GABAB antagonist, phaclofen (10 mM, 3 microliters), although lower doses (0.1-1 mM, 3 microliters) had no effect. These results suggest that the actions of GABA, presumably released from amacrine cells, on both GABAA and GABAB receptors are involved in the normal generation of the b-wave and OPs.

Animals↗