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PubMedDate not supplied

Quality of life and related factors among elderly nursing home residents in Southern Taiwan.

This study explored subjectively perceived quality of life and related factors of elderly nursing home residents. In this study, 161 residents aged 65 and older were selected from 10 nursing homes in Southern Taiwan. The results showed: (1) the mean score of quality of life was 15.86 and the standardized score was 52.87, a medium rating for the overall sample; (2) different educational levels, and socioeconomic status were significantly different in the quality of life, the other sociodemographic variables were not significantly different in the quality of life. (3) length of residence in the nursing home was significantly negative relative to the quality of life. Physical function, activities of daily living, social support from nurses, social support from nursing aides, social support from families, and frequency of family interaction were significantly positive relative to the quality of life. (4) Activities of daily living, social support from nurses, socioeconomic status, and physical function were the significant predictors in the quality of life, which explained 40.1% of the total amount of variance. Activities of daily living, social support from nursing aids, socioeconomic status, physical function and frequency of interaction with family were the significant predictors in the quality of life, which explained 39.5% of the total amount of variance. Results generated from this study may act as a reference for the staff of nursing homes to understand the quality of life and related factors among elderly residents. This study also acts as a reference for future intervention programs in this field.

Activities of Daily Living↗

PubMed2003

Minidose warfarin prophylaxis for catheter-associated thrombosis in cancer patients: can it be safely associated with fluorouracil-based chemotherapy?

PURPOSE: The use of prophylactic low-dose oral warfarin in cancer patients with a central venous catheter (CVC) in place has an established role in the prevention of thrombotic complications and is associated with a low hemorrhagic risk. Despite the literature indicating an adverse interaction between warfarin and fluorouracil (FU), the frequency of this interaction and whether it occurs when minidose warfarin is used is unknown. We analyzed the incidence of alterations in the International Normalized Ratio (INR) and bleeding in cancer patients given minidose warfarin during treatment with continuous-infusion FU-based regimens. PATIENTS AND METHODS: Between July 1999 and August 2001, 95 cancer patients were evaluated. Forty-one patients (43%) had liver metastases. Seventy-nine patients (83%) had a Groshong CVC (Bard Access System, Salt Lake City, UT), and 16 (17%) had a Port-a-Cath device (Bard Access System). All patients received oral warfarin at a dose of 1 mg/daily as prophylaxis beginning the day after the catheter was positioned. An INR of more than 1.5 was considered significantly elevated. RESULTS: INR elevation occurred in 31 patients (33%), with 18 patients (19%) having an INR more than 3.0. Twelve (39%) of the 31 patients had liver metastases. Bleeding was observed in eight patients (8%); seven of these patients had elevated INR levels. We observed INR elevations in 12 of 21 patients treated with a FU, folinic acid, and oxaliplatin (FOLFOX) regimen, 11 of 40 treated with a de Gramont regimen (FU and folinic acid), and five of 19 treated with a FU, folinic acid, and irinotecan (FOLFIRI) regimen. CONCLUSION: A high incidence of INR abnormalities was observed in our cohort of patients, especially those treated with FOLFOX regimen. Clinicians should be aware of this interaction and should regularly monitor the prothrombin time in patients receiving warfarin and FU.

Administration, Oral↗

PubMedDate not supplied

New fathers' blood pressure and heart rate: relationships to interaction with their newborn infants.

Cardiovascular changes in 148 first-time fathers while holding and interacting with their newborn infants are described and relationships of fathers' verbal and nonverbal behavior with these cardiovascular changes are discussed. Systolic and diastolic blood pressure (SBP, DBP) and heart rate (HR) were monitored before, during, and after interaction with the infants in a controlled hospital setting using a noninvasive oscillometric monitor. Subjects were videotaped during the interaction period. Analyses of cardiovascular responses controlled for preinteraction values revealed that all measures were significantly higher during interaction than during the postinteraction period. The frequency of fathers' verbal behaviors was negatively related to SBP and positively related to HR during interaction. Frequency of infant crying was positively related to fathers' DBP both during interaction and in the postinteraction period. Fathers appeared highly sensitive to the stimuli of interacting with their newborns and responded in a complex manner to infant signals. The findings may indicate an autonomic balance that is situationally specific.

Adolescent↗

PubMed1990

Interactions between sentence context and word frequency in event-related brain potentials.

Event-related brain potentials (ERPs) were recorded as subjects silently read a set of unrelated sentences. The ERP responses elicited by open-class words were sorted according to word frequency and the ordinal position of the eliciting word within its sentence. We observed a strong inverse correlation between sentence position and the amplitude of the N400 component of the ERP. In addition, we found that less frequent words were associated with larger N400s than were more frequent words, but only if the eliciting words occurred early in their respective sentences. We take this interaction between sentence position and word frequency as evidence that frequency does not play a mandatory role in word recognition, but can be superseded by the contextual constraint provided by a sentence.

Adolescent↗

PubMed1982

Social support and mortality in an elderly community population.

A community sample made in the fall of 1972 in Durham County, North Carolina, and that consisted of 331 persons 65 years of age and older was assessed for adequacy of social support along three parameters: roles and available attachments, perceived social support, and frequency of social interaction. This approach to the assessment of social support complements previous approaches to the measurement of social support which have not compared with the various components of the construct. Mortality status, the outcome variable, was determined 30 months after the initial assessment. The crude relative risks of mortality were 1.96 for impaired roles and available attachments, 3.86 for impaired perceived social support, and 2.72 for impaired frequency of social interaction. Ten potential confounding variables-age, sex, race, economic status, physical health status, self-care capacity, depressive symptoms, cognitive functioning, stressful life events, and cigarette smoking-were controlled using binary linear regression analysis. The estimates of relative mortality risk were 2.04, 3.40, and 1.88, respectively, for impaired roles and available attachments, impaired perceived social support, and impaired frequency of social interaction when the control variables were included in a regression model. Therefore, these three parameters of social support significantly predicted 30-month mortality in both crude and controlled analyses in a community sample of older adults.

Activities of Daily Living↗

PubMed2005

Interactions between cochlear implant electrode insertion depth and frequency-place mapping.

While new electrode designs allow deeper insertion and wider coverage in the cochlea, there is still considerable variation in the insertion depth of the electrode array among cochlear implant users. The present study measures speech recognition as a function of insertion depth, varying from a deep insertion of 10 electrodes at 28.8 mm to a shallow insertion of a single electrode at 7.2 mm, in four Med-El Combi 40+ users. Short insertion depths were simulated by inactivating apical electrodes. Speech recognition increased with deeper insertion, reaching an asymptotic level at 21.6 or 26.4 mm depending on the frequency-place map used. Başkent and Shannon [J. Acoust. Soc. Am. 116, 3130-3140 (2004)] showed that speech recognition by implant users was best when the acoustic input frequency was matched onto the cochlear location that normally processes that frequency range, minimizing the spectral distortions in the map. However, if an electrode array is not fully inserted into the cochlea, a matched map will result in the loss of considerable low-frequency information. The results show a strong interaction between the optimal frequency-place mapping and electrode insertion depth. Consistent with previous studies, frequency-place matching produced better speech recognition than compressing the full speech range onto the electrode array for full insertion ranges (20 to 25 mm from the round window). For shallower insertions (16.8 and 19.2 mm) a mild amount of frequency-place compression was better than truncating the frequency range to match the basal cochlear location. These results show that patients with shallow electrode insertions might benefit from a map that assigns a narrower frequency range than patients with full insertions.

Adult↗

PubMed1995

A test of the role of electrostatic interactions in determining the CO stretch frequency in carbonmonoxymyoglobin.

The vibrational frequency of CO bound to myoglobin can be varied by up to 60 cm-1 by making site-specific mutations in the distal pocket. These changes may result from specific chemical interactions between distal amino acids and the CO or from changes in the electrostatic field of the distal pocket. In this paper, we separate the relative contributions of these two effects by comparing the IR spectra of the carbonmonoxy complexes of human myoglobin mutants V68N, V68D, and V68E. The effect of replacing valine with these polar amino acids on the electrostatic environment of the distal heme pocket has been independently determined earlier by measurements of the heme reduction potential and electronic absorption spectral band shifts. While all three mutations result in a negative dipole pointing towards the CO ligand, the CO stretch frequency shifts differently in each case. These differences are attributed to specific chemical interactions between the amino acids and the CO ligand.

Electrochemistry↗

PubMedDate not supplied

Effect of perinatal monosodium glutamate administration on visual evoked potentials of juvenile and adult rats.

Administration of high doses of monosodium glutamate (MSG) to rats during the first postnatal week results in severe losses of retinal ganglion cells and interneurons in the retina. This study was conducted to determine what effect severe retinal damage would have upon the ontogeny of rat flash evoked potentials (FEPs) and the adult pattern reversal evoked potential (PREP). MSG (4 mg/g) or isotonic saline was administered to rat pups daily from postnatal day (PND) 2 until PND 9. FEPs were recorded following 2 stimulation frequencies from unanesthetized, unrestrained MSG treated and control rats on PND 15, PND 22, and PND 60 or older. PREPs were recorded from unanesthetized, restrained rats older than PND 60 from each treatment group. On PND 15, 9 of 12 control animals exhibited responses to light flashes, while only 4 of 13 MSG treated animals did so. All animals from both treatment groups exhibited FEPs on PND 22 and beyond. All FEP peak latencies were significantly increased in MSG treated animals with the magnitude of the effect being greater during development. Peak N1 amplitude was reduced in MSG treated animals by 50% or more at each age. Frequency x treatment interactions were observed on peak P2 and peak N3 latency, and a frequency x age x treatment interaction was observed on peak N3 amplitude. MSG treatment severely impaired the ability to generate PREPS. Only small responses to the pattern reversal stimulus could be detected and the normal PREP peaks could not be identified with confidence. Perinatal MSG treatment results in profound alterations in FEP ontogeny and the generation of PREPs.

Aging↗

PubMed2006

Efficient estimation of graphlet frequency distributions in protein-protein interaction networks.

MOTIVATION: Algorithmic and modeling advances in the area of protein-protein interaction (PPI) network analysis could contribute to the understanding of biological processes. Local structure of networks can be measured by the frequency distribution of graphlets, small connected non-isomorphic induced subgraphs. This measure of local structure has been used to show that high-confidence PPI networks have local structure of geometric random graphs. Finding graphlets exhaustively in a large network is computationally intensive. More complete PPI networks, as well as PPI networks of higher organisms, will thus require efficient heuristic approaches. RESULTS: We propose two efficient and scalable heuristics for finding graphlets in high-confidence PPI networks. We show that both PPI and their model geometric random networks, have defined boundaries that are sparser than the 'inner parts' of the networks. In addition, these networks exhibit 'uniformity' of local structure inside the networks. Our first heuristic exploits these two structural properties of PPI and geometric random networks to find good estimates of graphlet frequency distributions in these networks up to 690 times faster than the exhaustive searches. Our second heuristic is a variant of a more standard sampling technique and it produces accurate approximate results up to 377 times faster than the exhaustive searches. We indicate how the combination of these approaches may result in an even better heuristic. AVAILABILITY: Supplementary information is available at http://www.cs.toronto.edu/~natasha/BIOINF-2005-0946/Supplementary.pdf. Software implementing the algorithms is available at http://www.cs.toronto.edu/~natasha/BIOINF-2005-0946/estimate_grap-hlets.html. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.

Algorithms↗

PubMed1990

Mapping of collision frequencies for stearic acid spin labels by saturation-recovery electron paramagnetic resonance.

Short pulse saturation-recovery electron paramagnetic resonance methods have been used to measure interactions of 14N:15N stearic acid spin label pairs in multilamellar liposomal dispersions composed of dimyristoyl-phosphatidylcholine (DMPC) and dielaidoylphosphatidylcholine (DEPC). Pairs consisting of various combinations of [14N]-16-, [14N]-12- or [14N]-5-doxylstearate, and [15N]-16-, [15N]-12-, or [15N]-5-doxylstearate were studied. SR experiments were performed at 27 degrees and 37 degrees C, and recovery signals were analyzed for initial conditions and multiexponential time constants by computer fitting using a damped least-squares approach. The time constants contain combinations of the electron spin lattice relaxation time, Tle, for each member of the spin-label pair, and the Heisenberg exchange rate constant, Kx. Spin-lattice relaxation times for each of the 14N and 15N stearic acid spin labels were determined, and it is noted that Tle for a given 15N-SASL was always slightly greater than that of the corresponding 14N-SASL. From Kx the bimolecular collision frequency was calculated, providing a detailed picture of molecular interactions. For both lipid systems the bimolecular collision rates were ordered as 12:5 less than 16:5 less than 5:5 less than 16:12 less than 12:12 less than 16:16. For all spin-label pairs studied, interaction frequencies were greater in DMPC than in DEPC. For the 16:16, 12:12, and 16:12 pairs, Kx was approximately 30% greater in DMPC than in DEPC, a significantly greater difference than is observed by conventional EPR methods. Further confirmation of the existence of vertical fluctuation of nitroxide moieties that are at the 16- (or 12) position toward the polar surfaces was obtained, with the frequency of 16:5 (or 12:5) interactions ~40% of the 16:16 (or 12:12) interaction frequency. In both DMPC and DEPC, Kx for homogeneous pairs increases as the doxyl moiety is moved further down the alkyl chain (i.e.,5:5 < 12:12 < 16:16), suggesting that steric effects or the local rotational mobility of the nitroxide group influence the frequency at which spin exchange occurs.

Cyclic N-Oxides↗

PubMed1976

Teaching social skills to isolated children.

The effects of a social skill training program on socially isolated children are reported. The training program was derived from the results of a previous study of the specific social skills that discriminated popular from unpopular children. Training effects in the present investigation were assessed on sociometric position, and on the quality, frequency, and distribution of social interaction to peers. Time-series analyses were performed on the frequency and distribution of peer interaction. Two isolated children received social skill training with an adult coach, and two isolated children spent an equivalent amount of time with an adult. Results indicated that socially isolated children in the treatment group changed significantly in sociometric position on a follow-up assessment 9 weeks after the end of the intervention, did not change in the total frequency of peer social interaction, but did redistribute their interaction to peers. The two isolated children who did not receive the treatment program did not change significantly on the total frequency of peer interaction, and tended to withdraw from peers rather than redistribute their interaction. The insensitivity of total peer interaction frequency as a measure of outcome was discussed.

Behavior Therapy↗

PubMed1983

Involvement of the pituitary-adrenal axis in socio-behavioral disturbances after short-term isolation.

Short-term social isolation increased socio-explorative behavior of pairs of adult male Wistar rats. Hypophysectomy or adrenomedullectomy did not prevent this increase in social behavior. No differences between 7-day isolated (I) and non-isolated (socially housed, S) animals were observed in basal plasma corticosterone levels and these levels increased to the same level in I- and S-rats during individual exposure to the observation cage. The increase in corticosterone levels found immediately after the social interaction test was higher in I- than in S-rats. When I- and S-rats were tested together, a negative correlation was present between plasma-corticosterone levels and frequencies of social interactions. Blood pressure and heart rate were not affected by the isolation procedure. ACTH1-24 (5 micrograms/100 g) did not affect the frequencies of social interactions, neither in I- nor in S-rats. Although a role for corticosterone in "basal" social behavior could not be excluded, it seems that pituitary-adrenal hormones are not important for the development and expression of socio-behavioral disturbances due to short-term isolation.

Animals↗

PubMed2004

High frequency of defective sperm-zona pellucida interaction in oligozoospermic infertile men.

BACKGROUND: The ability of sperm to interact with the zona pellucida (ZP) plays a critical role during the process of human fertilization. The aim of this study is to determine frequency of defective sperm-ZP interaction in oligozoospermic infertile men. METHODS: Sperm-ZP binding assays and the ZP-induced acrosome reaction (AR) were performed in 72 infertile men with a sperm concentration <20 x 10(6)/ml. Oocytes that had previously failed to fertilize in a clinical IVF programme were used for the tests. Motile sperm (2 x 10(6)/ml) selected by swim-up from each semen sample were incubated with four oocytes for 2 h. The number of sperm bound per ZP and the ZP-induced AR were assessed. Under these conditions, an average of < or =40 sperm bound/ZP was defined as low sperm-ZP binding and a ZP-induced AR < or =16% was defined as low ZP-induced AR. RESULTS: In the 72 oligozoospermic men, 28% (20/72) had low sperm-ZP binding. Of those with normal sperm-ZP binding, 69% (36/52) had low ZP-induced AR. Overall, 78% (56/72) had either low ZP-binding or normal ZP binding but low ZP-induced AR. This means that only 22% (16/72) had both normal sperm-ZP binding and normal ZP-induced AR. CONCLUSION: Oligozoospermic men have a very high frequency of defective sperm-ZP interaction, consistent with their low natural fertility or low fertilization rate in conventional IVF. Infertile couples with oligozoospermic semen should be treated by ICSI rather than by conventional IVF.

Acrosome Reaction↗

PubMed1988

Objective evidence for phase-independent spatial frequency analysis in the human visual pathway.

Electrophysiological responses in human index an interaction between responses to two gratings that is relatively independent of the distribution of light in the retinal image. Two 5 cycle/deg sinewave gratings were superimposed, one counterphase-modulated at F1 Hz and the other at F2 Hz. Nonlinear interaction terms of frequency (nF1 +/- mF2) were recorded that could not be produced by superimposing the F1 Hz grating on blank-field 7 Hz flicker. A local luminance origin could be excluded for the (2F1 + 2F2) term and for the suppression of 2F1 and 4F1, but not for the (F1 + F2), (F1 + 3F2) and (5F2 - F1) terms. The relative spatial phase of the two gratings was varied, thus altering the light distribution in the retinal image without changing its spatial power spectrum. The (2F1 + 2F2) Hz contrast-specific grating-grating interaction term was almost unaffected by these substantial changes in retinal image light distribution providing that the spatial frequency power spectrum of the retinal image was held constant. The (2F1 + 2F2) term and the suppression of 2F1 were both tuned to spatial frequency.

Evoked Potentials, Visual↗

PubMed2006

Specificity of molecular interactions in transient protein-protein interaction interfaces.

In this study, we investigate what types of interactions are specific to their biological function, and what types of interactions are persistent regardless of their functional category in transient protein-protein heterocomplexes. This is the first approach to analyze protein-protein interfaces systematically at the molecular interaction level in the context of protein functions. We perform systematic analysis at the molecular interaction level using classification and feature subset selection technique prevalent in the field of pattern recognition. To represent the physicochemical properties of protein-protein interfaces, we design 18 molecular interaction types using canonical and noncanonical interactions. Then, we construct input vector using the frequency of each interaction type in protein-protein interface. We analyze the 131 interfaces of transient protein-protein heterocomplexes in PDB: 33 protease-inhibitors, 52 antibody-antigens, 46 signaling proteins including 4 cyclin dependent kinase and 26 G-protein. Using kNN classification and feature subset selection technique, we show that there are specific interaction types based on their functional category, and such interaction types are conserved through the common binding mechanism, rather than through the sequence or structure conservation. The extracted interaction types are C(alpha)-- H...O==C interaction, cation...anion interaction, amine...amine interaction, and amine...cation interaction. With these four interaction types, we achieve the classification success rate up to 83.2% with leave-one-out cross-validation at k = 15. Of these four interaction types, C(alpha)--H...O==C shows binding specificity for protease-inhibitor complexes, while cation-anion interaction is predominant in signaling complexes. The amine ... amine and amine...cation interaction give a minor contribution to the classification accuracy. When combined with these two interactions, they increase the accuracy by 3.8%. In the case of antibody-antigen complexes, the sign is somewhat ambiguous. From the evolutionary perspective, while protease-inhibitors and sig-naling proteins have optimized their interfaces to suit their biological functions, antibody-antigen interactions are the happenstance, implying that antibody-antigen complexes do not show distinctive interaction types. Persistent interaction types such as pi...pi, amide-carbonyl, and hydroxyl-carbonyl interaction, are also investigated. Analyzing the structural orientations of the pi...pi stacking interactions, we find that herringbone shape is a major configuration in transient protein-protein interfaces. This result is different from that of protein core, where parallel-displaced configurations are the major configuration. We also analyze overall trend of amide-carbonyl and hydroxyl-carbonyl interactions. It is noticeable that nearly 82% of the interfaces have at least one hydroxyl-carbonyl interactions.

Animals↗

PubMedDate not supplied

Retrospective analysis of postoperative nausea and vomiting to determine antiemetic activity of droperidol added to propofol: a possible drug interaction.

Propofol decreases the frequency of postoperative nausea and vomiting. We investigated whether its antiemetic activity could be improved further by coadministration of droperidol. We retrospectively reviewed the records of 266 women who underwent laparoscopic operations with nitrous oxide anesthesia and thiopental or propofol induction. The records were screened for frequency and time of occurrence of nausea and vomiting, concurrent drug use, duration of surgery, and times of recovery room admission and discharge. The combination of droperidol and thiopental decreased the frequency of nausea and vomiting over droperidol plus propofol, propofol alone, and thiopental alone. The addition of droperidol to propofol anesthesia doubled the frequency of multiple nausea and vomiting episodes, suggesting a possible interaction between the drugs. We cannot recommend that droperidol be added to propofol anesthesia for prophylaxis of postoperative nausea and vomiting.

Antiemetics↗

PubMed2003

The detection of gene-environment interaction for continuous traits: should we deal with measurement error by bigger studies or better measurement?

BACKGROUND: The search for biologically relevant gene-environment interactions has been facilitated by technological advances in genotyping. The design of studies to detect interactions on continuous traits such as blood pressure and insulin sensitivity is attracting increasing attention. We have previously described power calculations for such studies, and this paper describes the extension of those calculations to take account of measurement error. METHODS: The model considered in this paper is a simple linear regression relating a continuous outcome to a continuously distributed exposure variable in which the ratio of slopes for each genotype is considered as the interaction parameter. The classical measurement error model is used to describe the uncertainty in measurement in the outcome and the exposure. The sample size to detect differing magnitudes of interaction with varying frequencies of the minor allele are calculated for a given main effect observed with error both in the exposure and the outcome. The sample size to detect a given interaction for a given minor allele frequency is calculated for differing degrees of measurement error in the assessment of the exposure and the outcome. RESULTS: The required sample size is dependent upon the magnitude of the interaction, the allele frequency and the strength of the association in those with the common allele. As an example, we take the situation in which the effect size in those with the common allele was a quarter of a standard deviation change in the outcome for a standard deviation change in the exposure. If a minor allele with a frequency of 20% leads to a doubling of that effect size, then the sample size is highly dependent upon the precision with which the exposure and outcome are measured. rho(Tx) and rho(Ty) are the correlation between the measured exposure and outcome, respectively and the true value. If poor measures of the exposure and outcome are used, (e.g. rho(Tx) = 0.3, rho(Ty) = 0.4), then a study size of 150 989 people would be required to detect the interaction with 95% power at a significance level of 10(-4). Such an interaction could be detected in study samples of under 10 000 people if more precise measurements of exposure and outcome were made (e.g. rho(Tx) = 0.7, rho(Ty) = 0.7), and possibly in samples of under 5000 if the precision of estimation were enhanced by taking repeated measurements. CONCLUSIONS: The formulae for calculating the sample size required to study the interaction between a continuous exposure and a genetic factor on a continuous outcome variable in the face of measurement error will be of considerable utility in designing studies with appropriate power. These calculations suggest that smaller studies with repeated and more precise measurement of the exposure and outcome will be as powerful as studies even 20 times bigger, which necessarily employ less precise measures because of their size. Even though the cost of genotyping is falling, the magnitude of the effect of measurement error on the power to detect interaction on continuous traits suggests that investment in studies with better measurement may be a more appropriate strategy than attempting to deal with error by increasing sample sizes.

Environmental Exposure↗

PubMed2005

Low-frequency fatigue, post-tetanic potentiation and their interaction at different muscle lengths following eccentric exercise.

Low-frequency fatigue (LFF) and post-tetanic potentiation (PTP) were quantified at different muscle lengths in rat medial gastrocnemius (GM) muscle. In situ experiments were performed on GM muscle-tendon complexes of anaesthetised (urethane, 1.5 g kg(-1) i.p.) Wistar rats (N=8). Force-length characteristics were determined at maximal (200 Hz) and submaximal (60 Hz) stimulation. Data for submaximally stimulated muscle were obtained in a non-potentiated and in a potentiated condition. LFF was induced by a series of 40 eccentric contractions. Post-exercise (40-80 min), data for the force-length relationships were obtained once more. Whereas force loss at 200 Hz-stimulation was least at optimum muscle length, L(0,200 Hz), (17.0+/-1.4%, mean +/-S.E.M.), force loss at 60 Hz-stimulation was maximal near L(0,200 Hz) (55.1+/-4.3% at L(0,200 Hz)-1 mm). When the muscle was potentiated, force loss at 60 Hz-stimulation was maximal at short muscle length: L(0,200 Hz)-4 mm (53.5+/-3.8%). The extent of LFF, quantified by a decrease in the 60:200 Hz force ratio, varied with muscle length: LFF increased with decreasing muscle lengths when muscles were potentiated. However, in the non-potentiated condition, LFF was maximal at a length just below L(0,200 Hz); the 60:200 Hz force ratio had decreased to 54.6+/-5.9% of the pre-exercise ratio at L(0,200 Hz)-1 mm. Compared with the non-potentiated condition, LFF was less pronounced in the potentiated condition. PTP counteracted LFF particularly at long muscle lengths. However, at short muscle lengths, LFF was still observed in potentiated muscles.

Analysis of Variance↗