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PubMed2005

Effects of substerilizing doses of gamma radiation on adult longevity and level of inherited sterility in Teia anartoides (Lepidoptera: Lymantriidae).

The effects of substerilizing doses of gamma radiation on the longevity and level of inherited sterility in the Australian moth Teia anartoides Walker were determined. Six day-old male pupae were treated with 0, 100, and 160 Gy of gamma radiation by using a 1.25 MeV Cobalt60 irradiation source. Laboratory studies of male longevity showed that radiation had little impact in adult moths of the P1, F1, and F2 generations. Inherited deleterious effects resulting from irradiation were observed in the progeny of F1 and F2 generations. Outcrosses between substerile parental males or their highly sterile male progeny to wild-type females did not affect female fecundity. However, adverse effects were observed for these crosses in the rates of successful egg hatch and postembryonic development. Fertility was always greater in out-crosses involving a P1 male than in any of the F1 out-crosses. F1 males were always more sterile than F1 females, and the level of sterility for the F1 and F2 generations was higher than that of the controls. The incidence of larval and pupal mortality was higher in the F2 than the F1 generation. A dose of 100 Gy had the highest success in inducing deleterious effects that were inherited through to the F2 generation. Our results indicated that the use of partially sterilizing doses of radiation has good potential as a selective strategy for management or eradication of T. anartoides.

Animals↗
PubMed2001

Cross-resistance and resistance longevity as induced by bean leaf beetle, Cerotoma trifurcata and soybean looper, Pseudoplusia includens herbivory on soybean.

Cross-resistance, and longevity of resistance, induced by the bean leaf beetle, Cerotoma trifurcata, was studied IN the soybean PI 227687 that exhibited induced response in earlier studies. Bean leaf beetle adults and soybean looper, Pseudoplusia includens, larvae were used to induce resistance and to determine beetle feeding preference. Beetles were collected from soybean fields 2 to 5 days prior to the feeding preference test. The level of cross-resistance induced by soybean looper herbivory to subsequent bean leaf beetle feeding was higher when compared to cross-resistance induced by bean leaf beetle herbivory against subsequent feeding by soybean looper. Further, herbivory by the bean leaf beetle also induced resistance against soybean looper feeding. In the longevity study, leaflets from treated plants were collected 5, 10, 12, 14, 16, 20 and 25 days after initiation of feeding. Pairwise comparisons of leaflets from plants treated by bean leaf beetle herbivory with untreated plants revealed that induced responses were highest 14 and lowest 25 days after initiation of feeding. On other sampling days, levels of induced response varied with the sampling day.

Animals↗
PubMed2006

Cell Life versus cell longevity: the mysteries surrounding the NAD+ precursor nicotinamide.

Nicotinamide, the amide form of niacin (vitamin B(3)), is the precursor for the coenzyme beta-nicotinamide adenine dinucleotide (NAD(+)) and plays a significant role during the enhancement of cell survival as well as cell longevity. Yet, these abilities of nicotinamide appear to be diametrically opposed. Here we describe the development of nicotinamide as a novel agent that is critical for modulating cellular metabolism, plasticity, longevity, and inflammatory microglial function as well as for influencing cellular life span. The capacity of nicotinamide to govern not only intrinsic cellular integrity, but also extrinsic cellular inflammation rests with the modulation of a host of cellular targets that involve mitochondrial membrane potential, poly(ADP-ribose) polymerase, protein kinase B (Akt), Forkhead transcription factors, Bad, caspases, and microglial activation. Further knowledge acquired in regards to the ability of nicotinamide to foster cellular survival and regulate cellular lifespan should significantly promote the development of therapies against a host of disorders, such as aging, Alzheimer's disease, diabetes, cerebral ischemia, Parkinson's disease, and cancer.

Animals↗
PubMed2001

Egg longevity and time-integrated fertilization in a temperate sea urchin (Strongylocentrotus droebachiensis).

Recent field experiments have suggested that fertilization levels in sea urchins (and other broadcast spawners that release their gametes into the water column) may often be far below 100%. However, past experiments have not considered the potentially positive combined effects of an extended period of egg longevity and the release of gametes in viscous fluids (which reduces dilution rates). In a laboratory experiment, we found that eggs of the sea urchin Strongylocentrotus droebachiensis had high viability for 2 to 3 d. Fertilization levels of eggs held in sperm-permeable egg baskets in the field and exposed to sperm slowly diffusing off a spawning male increased significantly with exposure from 15 min to 3 h. In a field survey of time-integrated fertilizations (over 24, 48, and 72 h) during natural sperm release events, eggs held in baskets accrued fertilizations over as much as 48 h and attained fairly high fertilization levels. Our results suggest that an extended period of egg longevity and the release of gametes in viscous fluids may result in higher natural fertilization levels than currently expected from short-term field experiments.

Animals↗
PubMed1980

Reduced motility longevity in thawed human spermatozoa.

Fifty ejaculates from donors serving on an AID panel were divided into two 0.5 aliquots and evaluated for initial motility and kinetics. The first aliquot was then diluted with Tyrode solution and incubated in a Tyrode atmosphere at 37 degrees C. Motility and kinetics were evaluated at 1, 3, 6, and 9 hr. The second aliquot was frozen and thawed 24 hr later. The aliquot was then diluted with Tyrode solution, incubated, and evaluated as before. The results indicate a significant reduction in motility longevity of the thawed aliquots. A significant reduction in kinetics of the thawed aliquots was also discovered. These findings suggest that decreased motility longevity of thawed semen may offer an explanation for reduced pregnancy rates using cryopreserved semen.

Adolescent↗
PubMed2002

Bcl-2 controls dendritic cell longevity in vivo.

Dendritic cells (DC) were found to down-regulate Bcl-2 protein upon maturation in vivo. Because Bcl-2 has been shown to exert anti-apoptotic functions, down-regulation of Bcl-2 could be a mechanism by which DC longevity is controlled. To dysregulate this potential control system and to study the role of Bcl-2 in DC, we expressed human Bcl-2 under control of the murine CD11c-promoter as a transgene specifically in DC and show that DC frequencies and numbers increase in transgenic mice. In vivo bromodeoxyuridin, as well as adoptive, DC transfer studies show that the relative turnover/survival of mature Bcl-2 transgenic DC is increased. This had a direct impact on CD4+ T cell, as well as humoral immune, responses, which were elevated in transgenic animals. When Bcl-2 transgenic DC were used as DC vaccines, they induced 2- to 3-fold greater expansion of Ag-specific CTL, and stronger in vivo cytotoxicity. Overall, these data indicate that down-regulation of Bcl-2 controls DC longevity, which in turn directly regulates immune responses and the efficacy of DC when used as vaccines.

Animals↗
PubMed1997

Longevity of antibody responses to a Salmonella typhi-specific outer membrane protein: interpretation of a dot enzyme immunosorbent assay in an area of high typhoid fever endemicity.

The objective of this study was to investigate the longevity of positive dot enzyme immunosorbent assay (dot EIA) results for IgM and IgG to a Salmonella typhi outer membrane protein in Malaysian children with enteric fever. The patients were children one month to 12 years of age with clinical evidence of typhoid fever, positive blood or stool cultures for S. typhi, and/or a positive Widal test result who were admitted over a two-year period to General Hospital (Kota Bharu, Malaysia). These patients received standard inpatient treatment for enteric fever including chloramphenicol therapy for 14 days. Dot EIA tests were performed as part of clinical and laboratory assessments on admission, at two weeks, and then at 3, 6, 9, 12, 15, 18, and 21 months postdischarge. Assessment of the longevity of positive dot EIA IgM and IgG titers was done by Kaplan-Meier analysis. In 94 evaluable patients, 28% were dot EIA IgM positive but IgG negative on admission, 50% were both IgM and IgG positive, and 22% were IgM negative and IgG positive. Mean persistence of IgM dot EIA positivity was 2.6 months (95% confidence interval = 2.0-3.1 months) and that of IgG was 5.4 months (4.5-6.3 months). There were no significant differences between the three subgroups. Thus, positive IgM and IgG results determined by dot EIA within four and seven months, respectively, following documented or suspected enteric fever in a child from an endemic area should be interpreted with caution. In other clinical situations, the dot EIA remains a rapid and reliable aid to diagnosis.

Anti-Bacterial Agents↗
PubMed1978

Job longevity as a situational factor in job satisfaction.

This study investigates the relationships between overall job satisfaction and the five task dimensions of skill variety, task identity, task significance, autonomy, and feedback-from-job for employees at different stages of their careers, as measured by their length of employment on their current jobs, as well as in their current organizations. Basically, the analysis shows that the strength of the relationships between job satisfaction and each of the task dimensions depends on both the job longevity and organizational longevity of the sampled individuals. For employees new to an organization, for example, only task significance is related positively to job satisfaction, while autonomy has a strongly negative correlation. The study presents other significant correlational differences and discusses the implications of its findings for task design, as well as for managing new employees. Approximately 3500 respondents from four different governments--two metropolitan, one county, and one state--participated in the collection of survey data.

Job Satisfaction↗
PubMed1976

Permanent pacemaker treatment at Gentofte hospital. A follow-up study with special reference to transvenous electrode complications, generator longevity and control procedures.

Results of a follow-up study of 125 patients treated with permanent pacemakers at Gentofte Hospital during the years 1962--1973 are presented. Complications with endocardial electrodes are reported and longevity curves of pacemaker units are given. The series shows a high frequency of electrode displacement in the first three months and battery exhaustion from the 18th to the 42nd month. The appearance of complications correlates with the frequences of check-up intervals. In order to predict pacing failure due to battery exhaustion, there would seem to be some merit in carrying out an oscilloscopic display of the pulse artifact in addition to the usual measurement of pulse frequency. The aim of this retrospective report is, by analysing a pacemaker series for sudden eletrode failures and battery longevity, to comment on the value of check-up procedures in an outpatient pacemaker clinic.

Adult↗
PubMed2000

Longevity of oroincisal ceramic veneers on canines--a retrospective study.

PURPOSE: The longevity of oroincisal veneers on canines of IPS-Empress ceramic for the restoration of lost canine guidance was determined in a retrospective study. MATERIALS AND METHODS: Since 1992, all ceramic restorations made in the Department of Operative Dentistry have been entered in a data base. In that time period, 17 patients with 36 oroincisal veneers on canines to restore lost canine guidance have been documented. The survival rate of the restorations was calculated with the Kaplan-Meier method. RESULTS: The mean follow-up period was 6.74 years. The 6.5-year survival rate was 76%. The 6.5-year survival rate of canine oroincisal ceramic veneers in the maxilla was 74%, and in the mandible 78%. The difference in the survival rate of maxillary and mandibular restorations was not statistically significant. In the follow-up period, 8 of the 36 IPS-Empress canine veneers failed. Reasons for failure were ceramic fracture, fracture of the adhesive bond, and loss of function. CONCLUSION: In view of the longevity, the excellent properties of the IPS-Empress ceramic material, i.e., minimum abrasion of the opposing teeth, and good esthetics, we consider the restoration of lost canine guidance using this technique a viable alternative to the classical precious-metal pinledge or composite buildup.

Adult↗
PubMed1994

[Amalgam. XI. Glass-ionomer as a possible substitute of amalgam: longevity].

The clinical use of glass-ionomer increases, also for restorative goals. The longevity of glass ionomer restorations is among others determined by premature contact with saliva and by acid erosion. The adherence to the dental hard tissues may be increased by acid pretreatment. The longevity data presented here indicate that glass ionomer restorations do not last as long as amalgam restorations. In the deciduous teeth the material seems to be a more acceptable substitute for amalgam. The same holds true for restorations which are not submitted to stress, such as class V.

Acrylic Resins↗
PubMed2003

Further studies on autoclaved cercarial vaccine against schistosomiasis: safety, longevity and stability.

The autoclaved cercarial vaccine (ACV) which is a special type of killed vaccine has been reported to induce experimental high level of homologous protective immunity. This study was to adjust the dose and to assess vaccine safety, longevity and stability as well as the possibility of transplacental transmission of immune response from pregnant mice to their offspring. The results showed that two doses of the lowest most effective concentration of ACV that achieved the high percentage reduction of worm burden is safe as demonstrated by absence of any local or systemic side effects, normal blood picture and normal liver and kidney function tests. ACV is stable when kept either at 4 degrees C for six months or at -35 degrees C for up to 12 months and it offered considerable duration of longevity. Offspring of vaccinated mothers didn't show any signs of protection against challenge infection.

Animals↗
PubMed1992

Longevity of partial, complete and fixed prostheses: a literature review.

A review of the dental literature reveals a lack of consensus as to the longevity of conventional prosthodontic therapy. The reasons for this are suggested and best estimates of the longevity of partial, complete and fixed prostheses are presented based on the available literature. A renewed interest in survival studies, hopefully based on sound parameters that outline the reasons for failure, as well as replacement indicators, is required to update our knowledge of survival rates.

Denture, Complete↗
PubMed2006

Longevity of the tooth/restoration complex: a review.

The contemporary dentist has a wide variety of materials to utilize in the restoration of defective teeth. The decision as to which restorative approach should be utilized in any given clinical situation is a joint one between the patient and the treating dentist. The dentist's primary obligations are to understand the indications and contraindications of various materials, understand how to optimally manipulate those materials, and educate the patient so that they make intelligent decisions and give proper informed consent. The ultimate decision as to which approach to use rests with the patient, and the patient must clearly understand the benefits and risks associated with different restorative options. Clearly, one of the important considerations with any treatment is the prognosis and restoration longevity. When attempting to predict the long-term prognosis of any restoration, it is important to consider both the restorative material being considered as well as the specific tooth that is being restored. Many times the amount of remaining tooth structure has a more significant bearing on long-term prognosis than what material is used for restoration. Thus, the tooth/ restoration complex must be considered as a whole when predicting potential longevity. Many clinical trials have been conducted to attempt to answer those questions, and relatively few unbiased, unambiguous answers are available. The only completely honest answer to those questions is "It depends". This is because the prognosis of all restorative therapy depends on the complex interaction of a number of variables, some of which are controlled by the dentist, and some of which are totally out of the dentist's control. This article will attempt to delineate some of the factors related to the long-term prognosis of the tooth/restoration complex, and specifically identify factors that decrease the prognosis of the tooth/restoration complex.

Bruxism↗
PubMed1992

Will stress shielding limit the longevity of cemented femoral components of total hip replacement?

One must acknowledge the speculative nature of evaluating whether stress shielding will limit the longevity of cemented femoral components. One can, however, evaluate the data available from patients studied up to 20 years. Stress shielding does lead to disuse osteoporosis, particularly in the proximal medial cortex, and also more slowly and to a lesser extent elsewhere. Concern also exists that progressive endosteal enlargement will lead to failure of many or all cemented femoral stems. No evidence exists that disuse osteoporosis has limited the longevity of cemented femoral stems up to 20 years. Moreover, new data show that what has been described as the normal process of endosteal enlargement after inserting a cemented femoral component is a misinterpretation. What actually happens is that (1) neocortex develops around the cement mantle, (2) the original cortex thins, (3) the trabeculae in the zone of decreased density that develops between them maintain the structural integrity between those two bony masses, and (4) the implant remains rigidly fixed.

Bone Remodeling↗
PubMed1991

[Longevity of restorations in composite and etched porcelain].

Due to continuing alterations in composition of dental products and materials, prognoses about longevity of restorations in composite or etched porcelain are extremely difficult to make. Strength, wear resistance and resistance against disintegration determine durability of stress bearing restorations. Elasticity in combination with bond strength are determinant for prevention against premature leakage. Indication, cavity form and careful handling of the materials are prerequisites for longevity of the restoration. The prognosis of the favourably located but stress bearing class IV is far better than that of the unfavourable located, non stress bearing class V-composite restoration. For the etched porcelains, the veneers offer the best perspectives with respect to durability thanks to the favourable shrinkage pattern.

Acid Etching, Dental↗
PubMed1991

[Variations in reproductive capacity, gonotrophic cycle and longevity of Anopheles sinensis infected by Brugia malayi larvae].

Under the experimental conditions of 26 +/- 10 degrees C, relative humidity 70-80%, 100 +/- 20 Lux and photoperiod 16 hours/day and using a membrane feeding method, the development of filarial larvae and the variations in reproductive capacity, gonotrophic cycle and longevity of An. sinensis infected with microfilariae of Brugia malayi were observed. The infection rate and infection intensity of filarial larvae in An. sinensis increased with the microfilarial density in the blood meal from 50 to 150 mf/20 microliters. The mature rate and IEI decreased when the density rose to 200 mg/20 microliters. The concentration ratio of mf in blood by An. sinensis was 1.2-1.4. In the 3rd gonotrophic cycle, the feeding ratio of infected mosquitoes became lower when the mf density rose to 150 mf/20 microliters, but the infection of filarial did not affect the number of oviposition, the regularity of egg-production activity and the hatching rate of eggs, while the quantity of egg-production increased when the mf density was 150 mf/20 microliters. The egg-production rate, and gonotrophic cycle were not basically influenced by filarial larvae infection. The multifeeding ratio was 16.7-48.4% in An. sinensis. The longevity of An. sinensis was extended by infection with mf density of 100 mf/20 microliters and shortened in infection with mf density of 200 mf/20 microliters. The authors conclude that "Brugia malayi-Anopheles sinensis" is a highly adapted "pathogen-vector" system.

Animals↗
PubMed1986

Longevity of restorations in a dental school clinic.

The longevity of 1,207 restorations placed by students was studied in 70 adult patients. The overall percentage of restorations lasting ten years or more (P10) was 75.4 percent and survival times were longer than in most previous restoration longevity studies. Cast restorations lasted significantly longer than amalgams, which in turn lasted significantly longer than composites. P10 values were 91.1 percent, 72.0 percent, and 55.9 percent, respectively. Analysis by surfaces involved indicated that single-surface lasted longer than multisurface restorations. The survival of restorations placed in patients aged 60 or more was less favorable (P10 = 56.8 percent) than for younger patients (P10 = 78.3 percent). A subset of the population was identified on the basis of a restoration failure rate of greater than 4.0 X 10(-2) failures/restoration year. This group, comprising 18.6 percent of the population, accounted for 56.1 percent of all restoration failures. The P10 value for this high-risk group was 55.8 percent, as compared with 83.9 percent for the remainder of the population.

Adult↗