Long-term survival of patients receiving home hemodialysis with self-punctured arteriovenous access.

OBJECTIVE: To determine the long-term survival of patients receiving home hemodialysis (HHD) through self-punctured arteriovenous access. METHODS: We conducted an observational study of all patients receiving HHD at our facility between 2001 and 2020. The primary outcome was treatment survival, and it was defined as the duration from HHD initiation to the first event of death or technique failure. The secondary outcomes were the cumulative incidence of technique failure and mortality. Cox proportional hazard models were used to identify the predictive factors for treatment survival. RESULTS: A total of 77 patients (mean age, 50.7 years; 84.4% male; 23.4% with diabetes) were included. The median dialysis duration was 18 hours per week, and all patients self-punctured their arteriovenous fistula. During a median follow-up of 116 months, 30 treatment failures (11 deaths and 19 technique failures) were observed. The treatment survival was 100% at 1 year, 83.5% at 5 years, 67.2% at 10 years, and 34.6% at 15 years. Age (adjusted hazard ratio [aHR], 1.07) and diabetes (aHR, 2.45) were significantly associated with treatment survival. Cardiovascular disease was the leading cause of death, and vascular access-related issues were the primary causes of technique failure, which occurred predominantly after 100 months from HHD initiation. CONCLUSION: This study showed a favorable long-term prognosis of patients receiving HHD. HHD can be a sustainable form of long-term kidney replacement therapy. However, access-related technique failures occur more frequently in patients receiving it over the long term. Therefore, careful management of vascular access is crucial to enhance technique survival.

EFFECT OF TRYPSIN ON THE FERTILIZING CAPACITY OF SEA URCHIN SPERMATOZOA TREATED WITH EGG-WATER.

The effect of trypsin on the fertilizing capacity of spermatozoa was studied with 6 species of sea urchins. Trypsin has no harmful effect on intact spermatozoa. However, spermatozoa which have undergone the acrosome reaction in egg-water lose the fertilizing capacity when treated with trypsin-sea water. Electron- microscopical examination revealed that trypsin does not produce any morphologically noticeable effect on intact spermatozoa, but does dissolve the material covering the acrosomal tubule of the spermatozoa which have undergone the acrosome reaction. It is likely that the loss of this material is closely correlated with the loss of fertilizing capacity of spermatozoa by the trypsin treatment.

RELATION BETWEEN THE ACROSOME REACTION AND FERTILIZATION IN THE SEA URCHIN. II. FERTILIZATION IN ACIDIFIED SEA WATER WITH EGG-WATER-TREATED SPERMATOZOA.

Fertilization of sea urchin eggs fails to occur at a pH lower than 6.5. Analytical studies on this problem were made with Hemicentrotus pulcherrimus, Anthocidaris crassispina and Pseudocentrotus depressus. If the spermatozoa have been pretreated with egg water, eggs can be fertilized even at pH 6.5 and 6.0. The acrosome reaction is inhibited at a pH lower than 6.5. Intact spermatozoa fail to adhere to the fixed eggs in acidified sea water, whereas egg-water-treated spermatozoa adhere even at pH 6.5 and 6.0. From these results we infer that the failure of fertilization at pH 6.5-6.0 is caused by non-occurrence of the acrosome reaction, and that fertilization reactions other than the acrosome reaction, such as the binding and fusion of the gametes, are not inhibited in this range of pH. At pH 5.5, the spermatozoa become inert and fertilization is inhibited or suppressed, even though egg-water-treated spermatozoa are employed.

Induction of the Acrosome Reaction of Sea Urchin Spermatozoa by Means of Urea: (acrosome reaction/spermatozoa/urea/sea urchin).

Urea is an effective reagent for inducing the acrosome reaction of spermatozoa in sea urchins. Urea-treated spermatozoa are capable of fertilizing eggs in Ca-deficient sea water. The pH of the urea solution is an important factor affecting the induction of the acrosome reaction. The reaction occurs at a high percentage in urea Solution at pH's higher than 7.8, while the reaction is almost completely suppressed at pH 7.2. Ca++ is also an important factor for the induction of the reaction, although the minimum concentration required is very low. The acrosomal filament formed in urea solution is similar in shape to that formed in egg-water, when fixed after 10 seconds' urea-treatment. The acrosome granule material is found around the basal portion of the acrosomal filament.

SPECIES-SPECIFIC ADHESION OF SPERMATOZOA TO THE SURFACE OF FIXED EGGS IN SEA URCHINS.

When the spermatozoa of sea urchins are added to eggs which have been fixed with glutaraldehyde and washed thoroughly, the spermatozoa swarm around the eggs and adhere to the egg surface. The mode of sperm adhesion to the fixed egg is assumed, on the evidence of electron-microscopical studies, to be the same as that of adhesion to the intact egg at the initial stage of normal fertilization. The spermatozoa and fixed eggs of five species of sea urchins were combined and heterologous crosses were studied. Species-specific adhesion of sperm to fixed eggs was clearly demonstrated. There is a direct relationship between the cross-fertilization of living gametes and the binding capacity of spermatozoa and fixed eggs in so far as the employed five species are concerned.

RELATION BETWEEN THE ACROSOME REACTION AND FERTILIZATION IN THE SEA URCHIN. I. FERTILIZATION IN Ca-FREE SEA WATER WITH EGG-WATER-TREATED SPERMATOZOA.

When spermatozoa are treated with egg-water and undergo the acrosome reaction, their fertilizing capacity is lost within 5 min. However, if insemination is carried out within 4 min after the egg-water treatment, there is no difference in fertilizing capacity between spermatozoa treated with egg-water and non-treated ones. With such spermatozoa, eggs can be fertilized even in the virtual absence of calcium, whereas with spermatozoa treated with Ca-free egg-water, no fertilization occurs under the same conditions. It is postulated that in normal fertilization the acrosome reaction has occurred before the attachment of the gametes. The failure of fertilization with normal spermatozoa in Ca-free sea water may be due to the failure of occurrence of the acrosome reaction.

Fusion of Spermatozoa with Embryonic Cells and Somatic Cells in the Sea Urchin: (fertilization/re-fertilization/acrosome reaction/sea urchin).

Spermatozoa can enter the separated blastomeres of 8- and 16-cell stage embryos, the cells of blastulae and even somatic cells of the oesophagus wall of an adult sea urchin, under certain conditions. In the presence of egg jelly solution, the rate of entrance of spermatozoa is remarkably increased. In the case of the blastomere of 8-cell stage embryos, characteristic cytoplasmic protrusions are formed at the sites of sperm entry, in succession to the formation of the cytoplasmic bulge. These protrusions elongate until 4 min after insemination, and then they retract gradually. The nucleus of penetrated sperm swells and decondenses to form a pronucleus. In most cases, the pronucleus seems to fuse with the preexisting diploid nucleus of the blastomere. When the dissociated oesophagus cells were inseminated, a certain type of the cells was found to fuse with spermatozoa, although the percentage of fused cells was very low.

Multi-petal cyclamen flowers produced by AGAMOUS chimeric repressor expression.

Cyclamen persicum (cyclamen) is a commercially valuable, winter-blooming perennial plant. We cloned two cyclamen orthologues of AGAMOUS (AG), CpAG1 and CpAG2, which are mainly expressed in the stamen and carpel, respectively. Cyclamen flowers have 5 petals, but expression of a chimeric repressor of CpAG1 (CpAG1-SRDX) caused stamens to convert into petals, resulting in a flower with 10 petals. By contrast, CpAG2-SRDX only caused incomplete formation of stamens and carpels. Expression in Arabidopsis thaliana showed similar effects on flower organ specification. Simultaneous expression of CpAG1-SRDX and CpAG2-SRDX in cyclamen induced rose-like, multi-petal flowers, a potentially valuable trait in commercial ornamental varieties. Expression of CpAG2-SRDX in a cyclamen mutant lacking expression of CpAG1 more effectively produced multi-petal flowers. Here, we controlled the number of petals in cyclamen by simple genetic engineering with a chimeric repressor. This strategy may be applicable useful for other ornamental plants with two distinct AG orthologues.

Global approach to multichannel electroencephalogram analysis for diagnosis and clinical evaluation in mild Alzheimer's disease.

To establish an early diagnosis of Alzheimer's disease (AD), we evaluated brain spatial dynamics and cognitive function in mild AD. Seventeen patients with the diagnosis of mild AD and 17 age-matched controls were examined for Omega (global complexity), Sigma (total power) and Phi (generalized frequency) by 19-channel electroencephalography (EEG). As a result, the mild AD group showed significantly higher Omega values than the control group. The Phi values were highly correlated with the Mini-Mental State Examination scores and the full IQ and performance IQ scores of the Japanese Wechsler Adult Intelligence Scale Revised. These results indicate an increase in spatial complexity of the brain electric field in mild AD, as well as a close relationship between slowing of the global frequency of field changes and the cognitive decline in mild AD.