Violence Inflicted on Latina Transgender Women Living with HIV: Rates and Associated Factors by Perpetrator Type.

Many transgender individuals report violence directed against them. This study examined violence inflicted on transgender Latinas with HIV by primary partners, sexual partners and acquaintances/strangers. Logistic regression was used for analysis. 150 transgender Latinas were recruited. Rates of violence from different perpetrator types were 47-50%. For violence by primary partners, social support from cisgender people was associated with a lower likelihood of violence (AOR 0.56; CI 0.32, 0.98; p < 0.05). For violence by sexual partners, a history of childhood sexual abuse was associated with a higher likelihood of violence (AOR 2.64; CI 1.10, 6.34; p < 0.05). For violence by acquaintances/strangers, discrimination was associated with a higher likelihood of violence (AOR 2.84; CI 1.16, 6.94; p < 0.05) and social support from cisgender people with a lower likelihood (AOR 0.58; CI 0.37, 0.92; p < 0.05). Interventions are needed at individual, institutional and systemic levels to eradicate such violence.

RESUMEN: Muchas personas transgénero reportan violencia dirigida contra ellas. Este estudio examinó la violencia infligida a las mujeres transgénero latinas con VIH por sus parejas principales, parejas sexuales y conocidos/extraños. Se usó regresión logística para el análisis. 150 latinas transgénero fueron reclutadas. Las tasas de violencia de diferentes tipos de perpetradores fueron del 47­50%. Para la violencia por parte de parejas principales, el apoyo social de personas no transgénero se asoció con una menor probabilidad de violencia (AOR 0.56; CI 0.32, 0.98; p < 0.05). Para la violencia por parte de parejas sexuales, un historial de abuso sexual durante la niñez se asoció con una mayor probabilidad de violencia (AOR 2.64; CI 1.10, 6.34; p < 0.05). Para la violencia por parte de conocidos/extraños, la discriminación se asoció con una mayor probabilidad de violencia (AOR 2.84; CI 1.16, 6.94; p < 0.05) y el apoyo social de no-transgéneros con una menor probabilidad (AOR 0.58; CI 0.37, 0.92; p < 0.05). Se necesitan intervenciones a nivel individual, institucional y sistémico para erradicar dicha violencia.

Lipolysis and Fat Oxidation Are Not Altered with Presleep Compared with Daytime Casein Protein Intake in Resistance-Trained Women.

BACKGROUND: To date, no studies have directly compared the differences between presleep and daytime protein (PRO) consumption on localized and systemic fat metabolism in active women. OBJECTIVE: The purpose of this study was to assess the effects of presleep compared with daytime PRO supplementation on subcutaneous abdominal adipose tissue (SCAAT) lipolysis and whole-body substrate utilization in women. METHODS: Thirteen young (mean ± SE age: 22 ± 1 y; BMI: 24.3 ± 0.8 kg/m2), resistance-trained [1 repetition maximum (1RM) squat percentage of body weight: 135% ± 6%; 1RM bench press percentage of body weight: 82% ± 4%] women volunteered. On overnight experimental visits, participants performed full-body resistance exercise (RE; 65% 1RM) and were randomly assigned to consume either daytime PRO (PRO, 30 g casein) 30 min post-RE and presleep (30 min before bed) noncaloric, sensory-matched placebo (PLA, 0 g casein) (PRO-PLA), or the opposite (PLA-PRO), switching the order of the supplements on the following visit. SCAAT lipolysis, resting metabolism (indirect calorimetry), and plasma biomarkers (glucose, insulin, nonesterified fatty acids, glycerol) were measured at baseline, overnight, and the next morning. RESULTS: There were no differences in overnight SCAAT lipolysis between conditions indicated by interstitial glycerol concentrations (PRO-PLA: baseline, 669 ± 137; next morning, 321 ± 77.1; PLA-PRO: baseline, 524 ± 109; next morning, 333 ± 68.0 µM), fat oxidation (PRO-PLA: baseline, 5.70 ± 0.35; next morning, 5.00 ± 0.28; PLA-PRO: baseline, 6.59 ± 0.32; next morning, 5.44 ± 0.27 g/min), or any other measure. CONCLUSIONS: There was no difference between the effects of daytime and presleep PRO supplementation on SCAAT lipolysis or whole-body substrate utilization in resistance-trained women. Presleep PRO is a viable option for increasing PRO consumption in resistance-trained women because it does not blunt overnight lipolysis, and will therefore likely not lead to increases in subcutaneous abdominal fat.This trial was registered at clinicaltrials.gov as NCT03573687.

Thirst Increases Chorda Tympani Responses to Sodium Chloride.

In nature, water is present as a low-salt solution, thus we hypothesized that thirst would increase taste responses to low-salt solutions. We investigated the effect of thirst on the 2 different salt detection mechanisms present in the rat chorda tympani (CT) nerve. The first mechanism is dependent upon the epithelial sodium channel (ENaC), is blocked by benzamil, and is specific to the cation sodium. The second mechanism, while undefined, is independent of ENaC, and detects multiple cations. We expected thirst to increase benzamil-sensitive sodium responses due to mechanistically increasing the benzamil-sensitive ENaC. We recorded CT whole-nerve electrophysiological responses to lingual application of NaCl, KCl (30, 75, 150, 300, 500, and 600 mM), and imitation rainwater in both control and 24-h water-restricted male rats. NaCl solutions were presented in artificial saliva before and after lingual application of 5µM benzamil. Water restriction significantly increased the integrated CT responses to NaCl but not to KCl or imitation rainwater. Consistent with our hypothesis, only the benzamil-sensitive, and not the benzamil-insensitive, CT sodium response significantly increased. Additionally, CT responses to salt were recorded following induction of either osmotic or volemic thirst. Both thirsts significantly enhanced the integrated CT responses to NaCl and KCl, but not imitation rainwater. Interestingly, osmotic and volemic thirsts increased CT responses by increasing both the benzamil-sensitive and benzamil-insensitive CT sodium responses. We propose that thirst increases the sensitivity of the CT nerve to sodium.

The Transgender Women of Color Initiative: Implementing and Evaluating Innovative Interventions to Enhance Engagement and Retention in HIV Care.

To improve health outcomes among transgender women of color living with HIV, the Health Resources and Services Administration's Special Programs of National Significance program funded the Enhancing Engagement and Retention in Quality HIV Care for Transgender Women of Color Initiative in 2012. Nine demonstration projects in four US urban areas implemented innovative, theory-based interventions specifically targeting transgender women of color in their jurisdictions. An evaluation and technical assistance center was funded to evaluate the outcomes of the access to care interventions, and these findings will yield best practices and lessons learned to improve the care and treatment of transgender women of color living with HIV infection.

Temperature Influences Chorda Tympani Nerve Responses to Sweet, Salty, Sour, Umami, and Bitter Stimuli in Mice.

Temperature profoundly affects the perceived intensity of taste, yet we know little of the extent of temperature's effect on taste in the peripheral nervous system. Accordingly, we investigated the influence of temperature from 23 °C to 43 °C in 4 °C intervals on the integrated responses of the chorda tympani (CT) nerve to a large series of chemical stimuli representing sweet, salty, sour, bitter, and umami tastes in C57BL/J6 mice. We also measured neural responses to NaCl, Na-gluconate, Na-acetate, Na-sulfate, and MSG with and without 5 µM benzamil, an epithelial sodium channel (ENaC) antagonist, to assess the influence of temperature on ENaC-dependent and ENaC-independent response components. Our results showed that for most stimuli (0.5M sucrose, glucose, fructose, and maltose; 0.02M saccharin and sucralose; 0.5M NaCl, Na-gluconate, Na-acetate, Na-sulfate, KCl, K-gluconate, K-acetate, and K-sulfate; 0.05M citric acid, acetic acid, and HCl; 0.1M MSG and 0.05M quinine hydrochloride: QHCl), CT response magnitudes were maximal between 35 °C and 39 °C and progressively smaller at cooler or warmer temperatures. In contrast, the weakest responses to NH 4 Cl, (NH 4 ) 2 SO4, and K-sulfate were at the lowest temperature, with response magnitude increasing monotonically with increasing temperature, while the largest responses to acetic acid were at the lowest temperature, with response magnitude decreasing with increasing temperature. The response to sweet and umami stimuli across temperatures were similar reflecting the involvement of TRPM5 activity, in contrast to bitter stimuli, which were weakly affected by temperature. Temperature-modulated responses to salts and acids most likely operate through mechanisms independent of ENaC and TRPM5.

Comparisons of Bone Mineral Density Between Recreational and Trained Male Road Cyclists.

OBJECTIVE: To compare measures of training, performance, body composition, and areal bone mineral density (aBMD) between age-matched recreational and competitively trained male road cyclists. DESIGN: Cross-sectional. SETTING: Laboratory. PARTICIPANTS: Male cyclists (N = 28) aged 21-54 years riding more than 3 hours per week. ASSESSMENT OF RISK FACTORS: Men who train at high (≥8 h/wk) and moderate volumes (3-8 h/wk). MAIN OUTCOME MEASURES: Areal bone mineral density assessments by dual energy x-ray absorptiometry of the whole body, lumbar spine (L1-L4), right and left hips, maximal oxygen uptake (V[Combining Dot Above]O2max), and training history. RESULTS: Trained cyclists had higher power to weight (5.3 ± 0.4 vs 4.7 ± 0.3 W/kg, P = 0.001), V[Combining Dot Above]O2max (57.2 ± 4.5 vs 53.0 ± 6.1 mL·kg·min, P = 0.049) and training volume (10.6 ± 2.1 vs 6.3 ± 0.9 h/wk, P < 0.001) than recreational cyclists. Trained cyclists had lower right (0.898 ± 0.090 vs 0.979 ± 0.107 g/cm, P = 0.047) and left hip aBMD (0.891 ± 0.079 vs 0.973 ± 0.104 g/cm, P = 0.032). Z-scores identified lumbar (L1-L4) aBMD as osteopenic (-2.5 < Z-score < -1.0) in trained cyclists (-1.39 ± 1.09). Lumbar scans identified 12 trained and 4 recreational cyclists as osteopenic and 3 trained cyclists as osteoporotic. CONCLUSIONS: Areal bone mineral density is lower in trained male road cyclists compared with recreational, specifically at the hips. Lumbar aBMD is low in both trained and recreational cyclists. Research is needed to determine the chronic effects of cycling on aBMD and interventions that improve aBMD in this population. CLINICAL RELEVANCE: This study suggests road cycling may compromise aBMD and potentially increase the likelihood of low-trauma fractures; health care professionals should consider this exposure when exercise prescriptions are designed for patients at-risk for osteopenia/osteoporosis, for example, women and older adults.

Modified Daily Undulating Periodization Model Produces Greater Performance Than a Traditional Configuration in Powerlifters.

The primary aim of this study was to compare 2 daily undulating periodization (DUP) models on one-repetition maximum (1RM) strength in the squat, bench press, deadlift, total volume (TV) lifted, and temporal hormone response. Eighteen male, college-aged (21.1 ± 1.9 years) powerlifters participated in this study and were assigned to one of 2 groups: (a) traditional DUP training with a weekly training order: hypertrophy-specific, strength-specific, and power-specific training (HSP, n = 9) or (b) modified DUP training with a weekly training order: hypertrophy-specific, power-specific, and strength-specific training (HPS, n = 9). Both groups trained 3 nonconsecutive days per week for 6 weeks and performed the squat, bench press, and deadlift exercises. During hypertrophy and power sessions, subjects performed a fixed number of sets and repetitions but performed repetitions until failure at a given percentage during strength sessions to compare TV. Testosterone and cortisol were measured at pretesting and posttesting and before each strength-specific day. Hypertrophy, power, and strength produced greater TV in squat and bench press (p ≤ 0.05) than HSP, but not for deadlift (p > 0.05). For squat and deadlift, there was no difference between groups for 1RM (p > 0.05); however, HPS exhibited greater increases in 1RM bench press than HSP (p ≤ 0.05). Effect sizes (ES) showed meaningful differences (ES > 0.50) in favor of HPS for squat and bench press 1RM. Testosterone decreased (p ≤ 0.05) at weeks 5 and 6 and cortisol decline at weeks 3 and 4. However, neither hormone was different at posttesting compared with pretesting (p > 0.05). Our findings suggest that an HPS configuration of DUP has enhanced performance benefits compared with HSP.

Endovascular Treatment for Basilar Artery Occlusion.

Basilar artery occlusion (BAO) is a neurological emergency associated with a high risk for adverse outcomes. This review provides evidence on the therapeutic efficacy of intravenous thrombolysis (IVT) and endovascular therapy (EVT) in the treatment of BAO. Historically considered the primary intervention for acute ischemic stroke, IVT has been progressively combined with EVT, which has emerged from recent studies demonstrating clinical benefits, notably in patients presenting with severe stroke. Several randomised controlled trials have shown that EVT improves patient outcomes in select clinical contexts. Future research directions could address therapeutic treatment thresholds, combination strategies, and long-term outcomes.

The role of metabolic and bariatric surgery on the obesity pandemic in Latin America: A review of current practices and future directions.

Latin America faces a significant public health challenge due to the high prevalence of obesity and its associated diseases. Metabolic and bariatric surgery is effective and safe to treat obesity when other treatments fail; however, its implementation in Latin America remains unsatisfactory. This review explores the current status, challenges, and innovations of metabolic and bariatric surgery in Latin America. We searched peer-reviewed journals in English and Spanish for relevant articles published between 1998 and 2023. We found that more than 20% of the Latin American population is affected by obesity. Unfortunately, only a limited number of patients have access to metabolic and bariatric surgery due to high cost, limited availability, and shortage of specialists. The review found that ongoing clinical trials are being conducted in Brazil, Mexico, Chile, and Venezuela, indicating some regional progress. However, published studies remain low in number compared with other regions. Furthermore, we summarized the clinical outcomes, risks, and perioperative assessments associated with metabolic and bariatric surgery. We discussed potential strategies to enhance the availability and affordability of this intervention. This review emphasizes the significance of metabolic and bariatric surgery in addressing the obesity pandemic, specifically for Latin America, and proposes directions for future research and innovation.

Acetic acid modulates spike rate and spike latency to salt in peripheral gustatory neurons of rats.

Sour and salt taste interactions are not well understood in the peripheral gustatory system. Therefore, we investigated the interaction of acetic acid and NaCl on taste processing by rat chorda tympani neurons. We recorded multi-unit responses from the severed chorda tympani nerve (CT) and single-cell responses from intact narrowly tuned and broadly tuned salt-sensitive neurons in the geniculate ganglion simultaneously with stimulus-evoked summated potentials to signal when the stimulus contacted the lingual epithelium. Artificial saliva served as the rinse and solvent for all stimuli [0.3 M NH(4)Cl, 0.5 M sucrose, 0.1 M NaCl, 0.01 M citric acid, 0.02 M quinine hydrochloride (QHCl), 0.1 M KCl, 0.003-0.1 M acetic acid, and 0.003-0.1 M acetic acid mixed with 0.1 M NaCl]. We used benzamil to assess NaCl responses mediated by the epithelial sodium channel (ENaC). The CT nerve responses to acetic acid/NaCl mixtures were less than those predicted by summing the component responses. Single-unit analyses revealed that acetic acid activated acid-generalist neurons exclusively in a concentration-dependent manner: increasing acid concentration increased response frequency and decreased response latency in a parallel fashion. Acetic acid suppressed NaCl responses in ENaC-dependent NaCl-specialist neurons, whereas acetic acid-NaCl mixtures were additive in acid-generalist neurons. These data suggest that acetic acid attenuates sodium responses in ENaC-expressing-taste cells in contact with NaCl-specialist neurons, whereas acetic acid-NaCl mixtures activate distinct receptor/cellular mechanisms on taste cells in contact with acid-generalist neurons. We speculate that NaCl-specialist neurons are in contact with type I cells, whereas acid-generalist neurons are in contact with type III cells in fungiform taste buds.

Anion size modulates salt taste in rats.

The purpose of this study was to investigate the influence of anion size and the contribution of the epithelial sodium channel (ENaC) and the transient receptor potential vanilloid-1 (TRPV1) channel on sodium-taste responses in rat chorda tympani (CT) neurons. We recorded multiunit responses from the severed CT nerve and single-cell responses from intact, narrowly tuned and broadly tuned, salt-sensitive neurons in the geniculate ganglion simultaneously with stimulus-evoked summated potentials to signal when the stimulus contacted the lingual epithelium. Artificial saliva served as the rinse and solvent for all stimuli (0.3 M NH(4)Cl, 0.5 M sucrose, 0.03-0.5 M NaCl, 0.01 M citric acid, 0.02 M quinine hydrochloride, 0.1 M KCl, and 0.03-0.5 M Na-gluconate). We used the pharmacological antagonist benzamil to assess NaCl responses mediated by ENaC, and SB-366791 and cetylpyridinium chloride to assess responses mediated by TRPV1. CT nerve responses were greater to NaCl than Na-gluconate at each concentration; this was attributed mostly to broadly tuned, acid-generalist neurons that responded with higher frequency and shorter latency to NaCl than Na-gluconate. In contrast, narrowly tuned NaCl-specialist neurons responded more similarly to the two salts, but with subtle differences in temporal pattern. Benzamil reduced CT nerve and single-cell responses only of narrowly tuned neurons to NaCl. Surprisingly, SB-366791 and cetylpyridinium chloride were without effect on CT nerve or single-cell NaCl responses. Collectively, our data demonstrate the critical role that apical ENaCs in fungiform papillae play in processing information about sodium by peripheral gustatory neurons; the role of TRPV1 channels is an enigma.

Contribution of the TRPV1 channel to salt taste quality in mice as assessed by conditioned taste aversion generalization and chorda tympani nerve responses.

In rodents, at least two transduction mechanisms are involved in salt taste: 1) the sodium-selective epithelial sodium channel, blocked by topical amiloride administration, and 2) one or more amiloride-insensitive cation-nonselective pathways. Whereas electrophysiological evidence from the chorda tympani nerve (CT) has implicated the transient receptor potential vanilloid-1 (TRPV1) channel as a major component of amiloride-insensitive salt taste transduction, behavioral results have provided only equivocal support. Using a brief-access taste test, we examined generalization profiles of water-deprived C57BL/6J (WT) and TRPV1 knockout (KO) mice conditioned (via LiCl injection) to avoid 100 µM amiloride-prepared 0.25 M NaCl and tested with 0.25 M NaCl, sodium gluconate, KCl, NH(4)Cl, 6.625 mM citric acid, 0.15 mM quinine, and 0.5 M sucrose. Both LiCl-injected WT and TRPV1 KO groups learned to avoid NaCl+amiloride relative to controls, but their generalization profiles did not differ; LiCl-injected mice avoided the nonsodium salts and quinine suggesting that a TRPV1-independent pathway contributes to the taste quality of the amiloride-insensitive portion of the NaCl signal. Repeating the experiment but doubling all stimulus concentrations revealed a difference in generalization profiles between genotypes. While both LiCl-injected groups avoided the nonsodium salts and quinine, only WT mice avoided the sodium salts and citric acid. CT responses to these stimuli and a concentration series of NaCl and KCl with and without amiloride did not differ between genotypes. Thus, in our study, TRPV1 did not appear to contribute to sodium salt perception based on gustatory signals, at least in the CT, but may have contributed to the oral somatosensory features of sodium.

Water restriction and fluid temperature alter preference for water and sucrose solutions.

The role of diet temperature in ingestive behavior is poorly understood. We examined the importance of stimulus temperature and water-restriction state on the preference for and intake of water and sucrose. Using custom-designed equipment that allows us to monitor and maintain solution temperatures during testing (±0.1 °C), we conducted a series of 2-bottle preference tests (10 °C water vs. sucrose 10-40 °C) and brief access tests (10-40 °C water and sucrose). Water-restricted rats preferred cold water over any sucrose concentration (0.0-1.0 M) if the sucrose was 30 or 40 °C, whereas the same rats preferred sucrose at all concentrations and temperatures when unrestricted suggesting that the water-restriction state interacts with temperature preference. In a series of brief-access tests using a Davis Rig (MS-180), rats reduced licking to cold sucrose compared with 20 °C sucrose, suggesting that unlike water, cold temperature reduced the palatability of sucrose.

Attitudes towards depression of Argentinian, Chilean, and Venezuelan healthcare professionals using the Spanish validated version of the revised depression attitude questionnaire (SR-DAQ).

Background: The beliefs and attitudes of physicians toward depression may predict whether they are supportive or avoidant of patients diagnosed with this condition. Describing the attitudes toward depression of Argentinian, Chilean, and Venezuelan healthcare professionals could be a valuable tool for understanding the Latin American perspective on depression recognition, management, and prevention. Materials and methods: A cross-sectional study was conducted among healthcare professionals in Argentina, Chile, and Venezuela using the Spanish validated version of the revised depression attitude questionnaire (R-DAQ). The questionnaire was collected online from August to November 2021, in a quota-based sample of 1759 health professionals (the final analytical sample is 1234). Descriptive data analyses were performed using STATA version 16 statistical software. Results: Depression was considered a disease that anyone could suffer by 90% of the respondents. However, 70% of professionals answered that they feel more comfortable dealing with physical illness than mental illness. Furthermore, the findings show that a quarter of the participants in the study believed that either medical treatment (28.6%) or psychosocial approach (<20%) were ineffective tools for people suffering from depression. Findings also show that depression is seen as a more natural part of life by Argentinian professionals and men. Finally, psychologists and psychiatrists are most likely to treat depression as any other physical disease. Medical providers who routinely perform surgeries are not as likely to know how to treat depression or consider it an actual disease. Conclusions: Healthcare professionals in Argentina, Chile, and Venezuela have varying attitudes toward depression. While they recognize depression as a disease on the same level as other physical diseases, most do not know how to treat it. The findings point to the need for these countries to promote the training of healthcare workers in areas such as depression diagnosis, treatment, and social interventions.

A Community-Based Mindfulness Intervention Among Latino Adolescents and Their Parents: A Qualitative Feasibility and Acceptability Study.

Few studies have evaluated the effectiveness of mindfulness-based meditation interventions (MBMIs) among Latino youth. Furthermore, joint parent-child participation in such programs is rare. Utilizing a community-based participatory research approach, this study evaluated the feasibility of a pilot bilingual MBMI among Latino adolescents and their parents in Los Angeles. Qualitative interviews were conducted to assess the practicality, implementation, and acceptability of the program. Challenges to attendance included health issues or conflicts with work. Several adolescents struggled with distractions from peers. However, overall responses suggest that parents and children found the program convenient and enjoyable, and perceived benefits from the curriculum. This study supports the feasibility of a MBMI among Latino family dyads.

Initial Efficacy of a Community-Derived Mindfulness-Based Intervention for Latinx Parents and their Children.

Mindfulness-based interventions (MBIs) may offer a means for Latinx families to ameliorate stress, enhance emotion regulation, and foster social support. We assessed pilot data from Latinx parents in Eastside Los Angeles (n = 27) matched with their children aged 10-16 (n = 32) to determine whether participation in a community-derived MBI was associated with greater improvements in dispositional mindfulness, perceived stress, emotion regulation, and family social support compared to a control condition. Compared to the control group, parents in the MBI group showed greater reductions in perceived stress scale (PSS) scores (B = - 2.94, 95% CI [- 5.58, - 0.39], p = 0.029), while their children reported greater increases in perceived social support from family (B = 2.32, 95% CI [0.26, 4.38], p = 0.027). Findings show a community-derived MBI may improve stress in Latinx parents and social support for their children.

Response latency to lingual taste stimulation distinguishes neuron types within the geniculate ganglion.

The purpose of this study was to investigate the role of response latency in discrimination of chemical stimuli by geniculate ganglion neurons in the rat. Accordingly, we recorded single-cell 5-s responses from geniculate ganglion neurons (n = 47) simultaneously with stimulus-evoked summated potentials (electrogustogram; EGG) from the anterior tongue to signal when the stimulus contacted the lingual epithelium. Artificial saliva served as the rinse solution and solvent for all stimuli [(0.5 M sucrose, 0.03-0.5 M NaCl, 0.01 M citric acid, and 0.02 M quinine hydrochloride (QHCl)], 0.1 M KCl as well as for 0.1 M NaCl +1 µM benzamil. Cluster analysis separated neurons into four groups (sucrose specialists, NaCl specialists, NaCl/QHCl generalists and acid generalists). Artificial saliva elevated spontaneous firing rate and response frequency of all neurons. As a rule, geniculate ganglion neurons responded with the highest frequency and shortest latency to their best stimulus with acid generalist the only exception. For specialist neurons and NaCl/QHCl generalists, the average response latency to the best stimulus was two to four times shorter than the latency to secondary stimuli. For NaCl-specialist neurons, response frequency increased and response latency decreased systematically with increasing NaCl concentration; benzamil significantly decreased NaCl response frequency and increased response latency. Acid-generalist neurons had the highest spontaneous firing rate and were the only group that responded consistently to citric acid and KCl. For many acid generalists, a citric-acid-evoked inhibition preceded robust excitation. We conclude that response latency may be an informative coding signal for peripheral chemosensory neurons.

Cracking taste codes by tapping into sensory neuron impulse traffic.

Insights into the biological basis for mammalian taste quality coding began with electrophysiological recordings from "taste" nerves and this technique continues to produce essential information today. Chorda tympani (geniculate ganglion) neurons, which are particularly involved in taste quality discrimination, are specialists or generalists. Specialists respond to stimuli characterized by a single taste quality as defined by behavioral cross-generalization in conditioned taste tests. Generalists respond to electrolytes that elicit multiple aversive qualities. Na(+)-salt (N) specialists in rodents and sweet-stimulus (S) specialists in multiple orders of mammals are well characterized. Specialists are associated with species' nutritional needs and their activation is known to be malleable by internal physiological conditions and contaminated external caloric sources. S specialists, associated with the heterodimeric G-protein coupled receptor T1R, and N specialists, associated with the epithelial sodium channel ENaC, are consistent with labeled line coding from taste bud to afferent neuron. Yet, S-specialist neurons and behavior are less specific than T1R2-3 in encompassing glutamate and E generalist neurons are much less specific than a candidate, PDK TRP channel, sour receptor in encompassing salts and bitter stimuli. Specialist labeled lines for nutrients and generalist patterns for aversive electrolytes may be transmitting taste information to the brain side by side. However, specific roles of generalists in taste quality coding may be resolved by selecting stimuli and stimulus levels found in natural situations. T2Rs, participating in reflexes via the glossopharynygeal nerve, became highly diversified in mammalian phylogenesis as they evolved to deal with dangerous substances within specific environmental niches. Establishing the information afferent neurons traffic to the brain about natural taste stimuli imbedded in dynamic complex mixtures will ultimately "crack taste codes."

Whole-body Vibration Training in Frail, Skilled Nursing Home Residents.

Frailty is a geriatric syndrome characterized by diminished muscle strength, endurance, and weakened physical function. Physical frailty is often unaddressed clinically as it tends to manifest among chronic illnesses and sarcopenia, and consensus criteria for frailty diagnosis remains elusive. Whole-body vibration training (WBVT) has been used to improve deficits in lower body muscular strength and functional performance in healthy and high functioning older adults; therefore, the purpose of this study was to determine the effects of WBVT on physical frailty in skilled nursing home residents. This study compared the effects of 12 wks (2x/wk) of WBVT (n = 10) to standard care, which served as the control (CON: n = 10), on isometric knee extension strength (KE), body composition, and functional performance in 20 (16 female) pre-frail and frail skilled nursing home residents (82 ± 5 yrs). Frailty was assessed using the FRAIL scale and function was measured using the short physical performance battery (SPPB). WBVT consisted of 4 lower body exercises (partial squat, narrow squat, wide squat, calf raise) during vertical vibration (25 - 40 Hz). Data were analyzed using two-way ANOVA (group × time) and post-hoc paired and independent t-tests. Significance was set at p ≤ 0.05. There were significant group-by-time interactions for KE and SPPB. Post-hoc paired t-tests revealed that WBVT improved KE (22.3 ± 4.0 to 29.0 ± 4.5 kg) and improvement in SPPB performance approached significance (4.5 ± 2.3 to 5.2 ± 2.1 units, p = 0.089). WBVT was well tolerated and occurred without adverse health complications. WBVT can be used to counteract losses in leg strength without adverse health complications in skilled nursing home residents.

Saliva and other taste stimuli are important for gustatory processing of linoleic acid.

Paradoxically, bilateral transection of the chorda tympani nerve (CTX) raises the taste discrimination threshold for the free fatty acid, linoleic acid (LA), yet the chorda tympani nerve (CT) is unresponsive to lingual application of LA alone. LA may require a background of saliva to activate taste cells, since CTX decreases saliva production through denervation of the submaxillary and sublingual salivary glands. To assess the role of saliva, we measured LA taste discrimination thresholds for animals whose submaxillary and sublingual salivary glands were removed and also recorded CT responses to LA mixed in artificial saliva. Partial desalivation shifted LA discrimination thresholds from between 5.5 and 11 microM to between 11 and 22 microM. However, this effect was not as pronounced as previously seen with CTX animals. Surprisingly, the CT was unresponsive to LA mixed with artificial saliva, suggesting that artificial saliva may lack components necessary for LA taste. Additionally, fats may primarily enhance other tastes. We previously reported that LA increases CT responses to monosodium glutamate (MSG). Thus we also recorded CT whole nerve responses to taste mixtures of LA and sodium chloride (NaCl), sucrose (SUC), citric acid (CA), or quinine hydrochloride (QHCl) in anesthetized rats. We found that LA increased CT responses to NaCl but did not alter CT responses to SUC, CA, and QHCl. Thus CT recordings either lack the sensitivity to detect small changes to SUC, CA, and QHCl or LA may affect CT responses to MSG and NaCl only, perhaps by specifically modulating gustatory processing of Na(+).