Are there Sensitive Periods for Skill Development in Male Adolescent Basketball Players?

PURPOSE: Although spurts in physical capacities during adolescence are well-known, little is known about the existence of such spurts in sport-specific skill development, especially during the period of rapid growth in stature. Our aims were to examine the timing, intensity, and sequence of basketball-specific skill spurts aligned with biological [years from peak height velocity (PHV)] rather than chronological age. We then defined putative sensitive periods (windows of optimal development) for each skill aligned to the adolescent growth spurt. METHODS: Altogether, 160 adolescent male basketballers, aged 11-15 years, were tested bi-annually over three consecutive years. The years from attainment of PHV were estimated and six skill tests were aligned to each year from PHV in 3-month intervals. Skill velocities were estimated using a non-smooth polynomial model. RESULTS: Maximal gains in slalom dribble occurred 12 months prior to PHV attainment (intensity = 0.18 m·s-1·year-1), whereas in speed shot shooting (intensity = 9.91 pts·year-1), passing (intensity = 19.13 pts·year-1), and slalom sprint (intensity = 0.19 m·s-1·year-1) these skill spurts were attained 6 months prior to PHV attainment. The mean gains in control dribble (intensity = 0.10 m·s-1·year-1) and defensive movement (intensity = 0.12 m·s-1·year-1) peaks coincided with attainment of PHV. We identified different sized windows for optimal development for each skill. CONCLUSIONS: Peak spurts in skill development, for most basketball skills, were attained at the same time as PHV. The multiple peaks observed within the defined windows of optimal development suggest that there is room for skill improvement even if gains might be greater earlier rather than later in practice. Our findings highlight the need to make coaches aware of where their players are relative to the attainment of PHV since different skills appear to develop differently relative to PHV. Such knowledge may help in designing more relevant training regimes that incorporate the athlete's current growth status so that skill development can be maximized.

Corpora cavernosa fibroblasts mediate penile erection.

Penile erection is mediated by the corpora cavernosa, a trabecular-like vascular bed that enlarges upon vasodilation, but its regulation is not completely understood. Here, we show that perivascular fibroblasts in the corpora cavernosa support vasodilation by reducing norepinephrine availability. The effect on penile blood flow depends on the number of fibroblasts, which is regulated by erectile activity. Erection dynamically alters the positional arrangement of fibroblasts, temporarily down-regulating Notch signaling. Inhibition of Notch increases fibroblast numbers and consequently raises penile blood flow. Continuous Notch activation lowers fibroblast numbers and reduces penile blood perfusion. Recurrent erections stimulate fibroblast proliferation and limit vasoconstriction, whereas aging reduces the number of fibroblasts and lowers penile blood flow. Our findings reveal adaptive, erectile activity-dependent modulation of penile blood flow by fibroblasts.

A New Developmental Approach for Judo Focusing on Health, Physical, Motor, and Educational Attributes.

Judo is currently the most practiced combat sport in the world. There is no doubt of its importance for children, adolescents, adults, and seniors. However, due to its inherent complexity, coaches tend to place greater or lesser emphasis only on one of its multiple domains during the judoka formative years. The present study presents a novel developmental approach signaling Judo as an excellent way for physical, motor, educational, and health development across the lifespan. In this study, we consulted 23 Judo coaches, aiming to clarify the relevance and adequacy of the domains (Competitive, Health, Technical-Tactical, and Philosophical-Educational) and phases of the proposed model. Our findings showed that the model contents-physical, motor, educational, and health-are entwined with its four domains, which were considered of utmost importance by experts in the development of judokas. We, therefore, contend that our model is essential to better understand the growth and development of young judokas. Also, it may be a useful tool for Motor Development experts.

The effects of body size and training environment on the physical performance of adolescent basketball players: the INEX study.

BACKGROUND: Although adolescent basketballers differ in body size, shape, and composition, less is known about how these factors interact during physical development. AIM: We used ontogenetic allometry to identify the optimal body size and shape characteristics associated with physical performance in adolescent basketball players, and investigated the effects of training experience, training volume, maturity status, and club characteristics on physical performance development. SUBJECTS AND METHODS: Two hundred and sixty-four male basketballers, from five age-cohorts (11-15 years of age), were followed consecutively over three years. Three physical performance components, anthropometrics, training information, and biological maturation were assessed bi-annually. Longitudinal multiplicative allometric models were developed. RESULTS: Players with a physique that had a dominant ectomorphic component performed better in all physical performance components. When adjusting for confounders other than size, the development of running speed was independent of body size. Players advanced in maturation were physically fitter. Training data had no significant effect on developmental trajectories of running speed or lower body explosive strength. Club characteristics had no significant association with any physical performance trajectories. CONCLUSION: Leaner players have advantages in physical performance and individual characteristics play an important role, over and beyond club structure, in developing physical performance.

Classification of the Effort Index and Biomechanical Overload in Natural Trails of UNESCO Global Geoparks-A Network Perspective of Trails of the Araripe UGG (NE Brazil).

Natural trails in UNESCO Global Geopark territories show strong salutogenic, inclusive and interactive characteristics as potentials and opportunities for ecosystem health. It is essential to provide information to inform the hiker as to the characteristics of the environment and the attractions and challenges of the route. Based on a network analysis methodology we aimed to identify the indicators of centrality and strength of connection in order to classify the effort index and biomechanical overload of the Araripe UNESCO Global Geopark trails in Brazil. The results showed strong connection and centrality of the variables related to the biomechanical overload in the effort index. In the trail of Pontal de Cruz the altimetric variation and the surface of the ground are highlighted in the biomechanical overload that presented a horizontal course equivalent 2.6 times larger than the presented distance. In Sítio Fundão trail, the surface of the ground also stood out, increasing the exposure in 36% of the presented distance. On the Missão Velha Waterfall trail, the variable that stood out was the biomechanical overload on the knee, equivalent to a horizontal increase of 28% of the measured distance. The methodology presented sought to optimise the mapping, management and consolidation of a network of natural trails aggregated to a high geotouristic, scientific, educational, cultural and well-being potential as presented in the Araripe UGG territory.

Physical fitness spurts in pre-adolescent boys and girls: Timing, intensity and sequencing.

We aim to (1) estimate age of attainment of the peak mid-growth spurt in stature (age-at-peak MGS) in pre-adolescent boys and girls; (2) identify the timing, intensity, and sequences of physical fitness (PF) spurts aligned by the age-at-peak MGS; and (3) identify any sex differences in PF spurts aligned by age-at-peak MGS. The sample included 180 Portuguese children (90 girls) aged 6 to 10 years at study entry who were followed annually for 4 years. Height, health-, and performance-related PF were assessed. Age-at-peak MGS and PF spurts were estimated using a non-smooth mathematical procedure. Boys' and girls' age-at-peak MGS occurred at 7.8 ± 0.47 years and 8.0 ± 0.72 years, respectively. PF spurts' timing aligned by age-at-peak MGS were as follows: (1) before age-at-peak MGS: boys - static strength, aerobic capacity, explosive leg strength, and flexibility; girls - speed, agility, aerobic capacity, and upper body strength; (2) coincident with age-at-peak MGS: girls - explosive leg strength and flexibility; (3) after age-at-peak MGS: boys - abdominal strength, upper body strength, agility, and speed; girls - abdominal strength and static strength. Boys and girls attained their MGS at relatively similar ages. However, the timing and sequences of PF spurts, aligned on age-at-MGS, were different between boys and girls.

Modelling the dynamics of change in the technical skills of young basketball players: The INEX study.

Although technical skills are a prerequisite for success in basketball, little is known about how they develop over time. In this study, we model the trajectories of technical skill development in young basketball players and investigate the effects of training experience, training volume, body composition, maturity status, physical performance, and club characteristics on skill development. A total of 264 male basketballers from five age-cohorts (11 to 15 years of age) were followed consecutively over three years using a mixed-longitudinal design. Technical skills, training experience and volume, basic anthropometrics, body composition, biological maturation and physical performance were assessed bi-annually. A multilevel hierarchical linear model was used for trajectory analysis. Non-linear trends (p < 0.01) were observed in speed shot shooting, control dribble, defensive movement, slalom sprint, and slalom dribble. Being more experienced and physically fitter had a significant (p < 0.05) positive effect on technical skill development; greater fat-free mass negatively affected skills demanding quick running and rapid changes of direction with or without the ball (p < 0.05). Training volume and biological age did not explain differences in technical skill development (p > 0.05). Moreover, belonging to different clubs had no significant influence on the technical skills trajectories of players. Our findings highlight the important role that individual differences play, over and beyond club structure, in developing skills. Findings improve our understanding on how technical skills develop during adolescence through training, growth, and biological maturation.

Astrocyte-derived neurons provide excitatory input to the adult striatal circuitry.

Astrocytes have emerged as a potential source for new neurons in the adult mammalian brain. In mice, adult striatal neurogenesis can be stimulated by local damage, which recruits striatal astrocytes into a neurogenic program by suppression of active Notch signaling (J. P. Magnusson et al., Science 346, 237-241 [2014]). Here, we induced adult striatal neurogenesis in the intact mouse brain by the inhibition of Notch signaling in astrocytes. We show that most striatal astrocyte-derived neurons are confined to the anterior medial striatum, do not express established striatal neuronal markers, and exhibit dendritic spines, which are atypical for striatal interneurons. In contrast to striatal neurons generated during development, which are GABAergic or cholinergic, most adult astrocyte-derived striatal neurons possess distinct electrophysiological properties, constituting the only glutamatergic striatal population. Astrocyte-derived neurons integrate into the adult striatal microcircuitry, both receiving and providing synaptic input. The glutamatergic nature of these neurons has the potential to provide excitatory input to the striatal circuitry and may represent an efficient strategy to compensate for reduced neuronal activity caused by aging or lesion-induced neuronal loss.

Body Physique, Body Composition, Physical Performance, Technical and Tactical Skills, Psychological Development, and Club Characteristics of Young Male Portuguese Soccer Players: The INEX Study.

Youth soccer performance is multifaceted, includes physical growth, biological maturation, and physical fitness, and is linked to the sporting environment to which the players are exposed. We aim to describe age-related associations in body physique, body composition, physical performance technical and tactical skills, psychological and club characteristics of male soccer players aged 12 to 14 years. A total of 157 male soccer players clustered into three age-cohorts (12, 13 and 14 years) were recruited from six soccer clubs. Anthropometric, body composition and body physique, biological maturation, physical performance, skill/game proficiency data, psychological characteristics, and clubs' characteristics were collected. Group means were compared using analysis of variance and covariance. Fourteen years old players were significantly taller, heavier, leaner, faster, stronger, and technically more skilled than their younger peers (p < 0.05). Differences in physical performance and technical skills (p < 0.05) were found between age groups when adjusting for confounders of soccer training and biological maturation. No significant differences (p > 0.05) between age groups were found in psychological domains. Our findings suggest that age, biological maturation, and training volume are key factors influencing young soccer players' performance and development. Further, clubs' conditions provide players with ample resources for their success in training and competition.

Physical fitness spurts in childhood: A study in boys.

This study aimed to (1) estimate age-at-mid-growth spurt (age-at-MGS) in Portuguese boys from two different regions-the Azores islands and Viana do Castelo, and (2) identify spurts in a variety of physical fitness (PF) components aligned by age-at-MGS in the two samples. A total of 176 (Azores, n = 91; Viana do Castelo, n = 85) boys aged 6 years old were followed annually to 10 years of age. Age-at-MGS and spurts in PF components (speed, explosive muscular strength, abdominal muscular strength, agility, and flexibility) were identified for each sample. The timing and intensities of the spurts were estimated using a non-smooth mathematical procedure. In Azorean boys, age-at-MGS occurred at 7.8 years (6.99 cm y-1 ), whereas in Viana do Castelo it occurred at 7.9 years (6.20 cm y-1 ). Spurt in speed was attained 12 months after the MGS in both samples (0.53 and 0.35 cm y-1 in Azores and Viana do Castelo, respectively), whereas spurts in explosive muscular strength and flexibility occurred 12 months before the MGS and at the MGS (Azores: 21.59 and 5.52 cm y-1 and Viana do Castelo: 14.12 and 2.5 cm y-1 , respectively). Agility and abdominal muscular strength peaked between 0 and 12 months after the MGS (Viana do Castelo: 0.37 m s-1  y-1 and 6.71 reps y-1 and Azores: 0.28 m s-1  y-1 and 19.36 reps y-1 , respectively). Results indicate that developmental spurts in explosive strength and flexibility occur before, or are coincident with, the mid-growth spurt in height, whereas spurts in speed, agility, and abdominal muscular strength occur after, or coincident with, the mid-growth spurt in height.

Tracking Technical Skill Development in Young Basketball Players: The INEX Study.

This study investigated developmental stability, or tracking, in the development of technical skills in youth male basketball players and retrospectively profiled stable and unstable tracking patterns over time. A total of 97 basketball players were tracked bi-annually over 3 consecutive years. Players were divided into two age-categories according to their age at baseline: under-12; and under-14. Technical skills were assessed using the American Alliance for Health, Physical Education, Recreation and Dance test battery. Anthropometric, body composition, biological maturation and physical performance data were collected. Cohen's kappa (κ) was used to estimate tracking. With the exception of defensive movement in the under-12 age-category, tracking was low in all skill tests for both under-12 (0.22 ≤ κ ≤ 0.33) and -14 (0.20 ≤ κ ≤ 0.26) groupings. The overall technical skill showed moderate tracking for under-12 players (κ = 0.47) and low tracking for under-14 players (κ = 0.26). At baseline, players who were consistently more skilled or became more skillful (in the under-12 age-category) over time had a better growth-motor performance profile and most of them were selected to be members of regional teams. In conclusion, tracking of individual skill trajectories was low-to-moderate. Moreover, a better growth-motor performance profile seems crucial to maintain high levels of skill performance over time. It is recommended that basketball coaches track the developmental trajectories of their players to better understand the erratic nature of skill development and help design more effective practice regimes.

Muscular Strength Spurts in Adolescent Male Basketball Players: The INEX Study.

Although successful performance in basketball requires high levels of muscular strength during adolescence, its development is confounded by the effects of normal growth. We examine the timing, intensity and sequence of muscular strength according to biological age (years from peak height velocity (PHV)) and hypothesize that young basketball players attain their peak muscular strength spurts around PHV. A total of 160 adolescent male basketballers, aged 11-15 years, were followed bi-annually over 3 consecutive years. The years from attainment of PHV and peak weight velocity (PWV) were estimated and five muscular strength measures (sit-ups, handgrip, seated medicine ball throw, squat jump and countermovement jump) were aligned to years from PHV in 3-month intervals. Strength velocities were estimated using a non-smooth mathematical model. The mean ages at-PHV and at-PWV were 13.90 ± 1.40 years and 13.90 ± 1.79 years, respectively. Maximal velocity in sit-ups was attained 6 months prior to attainment of PHV (intensity = 10.69 repetitions·year-1), whereas maximal velocity in squat jump occurred 6 months after-PHV (intensity = 3.93 cm·year-1). Handgrip strength, seated medicine ball throw and countermovement jump maximal velocity peaked at-PHV (intensity = 8.47 kgf·year-1, intensity = 0.75 m·year-1, intensity = 5.59 cm·year-1, respectively). In general, maximal velocity spurts did not differ in their timing, with the velocities reaching a peak concurrent with PHV and PWV or within 6 months of its attainment. Basketball coaches, as well as strength and conditioning trainers, should consider individual differences in strength development and be aware of rapid periods of growth in stature when planning and designing muscular strength training regimes.

The role of growth, maturation and sporting environment on the development of performance and technical and tactical skills in youth basketball players: The INEX study.

In this paper, we outline a systematic testing programme developed to help identify excellence in youth basketball players. We examine the links between biological maturation and training experience with anthropometry, body composition, physical performance, technical and tactical skills from five age-cohorts, and characterize, in detail, facets of their environment. In total, 238 young basketball players aged 11-15 years, clustered into five age-cohorts (11, 12, 13, 14, 15 years) were recruited. We assessed measures across three domains: (1) biological [anthropometry, body composition, biological maturation and physical performance]; (2) skill/game proficiency [technical skills and tactical skills]; and (3) contextual [family support, coach knowledge and competence and club context]. The data were analysed using one-way ANOVAs and multivariate analysis of covariance adjusting for biological maturation and training experience. We report significant differences favouring older basketball players on most biological and skill/game proficiency variables. However, differences between age-cohorts in physical performance and technical skills were mitigated after controlling for the effects of both covariates. In conclusion, our findings highlight the important role of both biological maturation and training experience on youth basketball players' performance and development. We discuss the implications of these findings for research as well as for athletes, parents, coaches and clubs.

Patterns of physical performance spurts during adolescence: a cross-cultural study of Canadian, Brazilian and Portuguese boys.

BACKGROUND: Data relating physical performance to the timing of the adolescent growth spurt are limited. Aim: This study identifies: (i) age-at-peak height velocity (APHV), (ii) physical performance spurt patterns aligned to APHV; and (iii) cross-cultural and time patterns in Canadian, Brazilian and Portuguese boys. Subjects and methods: A total of 512 boys (131 Canadian, 250 Portuguese and 131 Brazilian), 8-17 years of age were followed serially using longitudinal data. APHV was identified and five physical performance measures velocities [trunk extension (TE), trunk flexion (TF), standing long jump (SLJ), curl-ups (CU) and handgrip strength (HG)] were aligned at 6-month intervals, 4 years around the attainment of PHV. Velocities were estimated using a non-smooth mathematical procedure. Results: APHV was 13.9 ± 1.0, 13.4 ± 1.6 and 13.0 ± 0.8 years for Canadian, Brazilian and Portuguese boys, respectively. Maximal velocity in SLJ was attained between 12 and 6 months prior to PHV. For HG, peaks were attained 12-24 months after PHV. Maximal velocity in TE occurred between 12 and 0 months prior to PHV, while CU peaked between PHV and 6 months after PHV. Conclusion: Patterns of spurts in physical performance have remained relatively the same and do not appear to be influenced by cross-cultural differences.

Circadian vulnerability of cisplatin-induced ototoxicity in the cochlea.

The chemotherapeutic agent cisplatin is renowned for its ototoxic effects. While hair cells in the cochlea are established targets of cisplatin, less is known regarding the afferent synapse, which is an essential component in the faithful temporal transmission of sound. The glutamate aspartate transporter (GLAST) shields the auditory synapse from excessive glutamate release, and its loss of function increases the vulnerability to noise, salicylate, and aminoglycosides. Until now, the involvement of GLAST in cisplatin-mediated ototoxicity remains unknown. Here, we test in mice lacking GLAST the effects of a low-dose cisplatin known not to cause any detectable change in hearing thresholds. When administered at nighttime, a mild hearing loss in GLAST KO mice was found but not at daytime, revealing a potential circadian regulation of the vulnerability to cisplatin-mediated ototoxicity. We show that the auditory synapse of GLAST KO mice is more vulnerable to cisplatin administration during the active phase (nighttime) when compared to WT mice and treatment during the inactive phase (daytime). This effect was not related to the abundance of platinum compounds in the cochlea, rather cisplatin had a dose-dependent impact on cochlear clock rhythms only after treatment at nighttime suggesting that cisplatin can modulate the molecular clock. Our findings suggest that the current protocols of cisplatin administration in humans during daytime may cause a yet undetectable damage to the auditory synapse, more so in already damaged ears, and severely impact auditory sensitivity in cancer survivors.

How Does Biological Maturation and Training Experience Impact the Physical and Technical Performance of 11-14-Year-Old Male Basketball Players?

This study (1) investigated the effects of age, maturity status, anthropometrics, and years of training on 11-14-year-old male basketball players' physical performance and technical skills development, and (2) estimated the contribution of maturity status and training years on players' physical and technical performances. The sample consisted of 150 participants, average age 13.3 ± 0.7 years, grouped by early, average, and late maturation. Biological maturation, anthropometry, and training data were collected using standard procedures. Measures of physical performance assessed included: aerobic fitness, abdominal muscular strength and endurance, static strength, lower body explosive power, upper body explosive power, speed, and agility and body control. Basketball-specific technical skills were also recorded. Analysis of variance (ANOVA) and analysis of covariance (ANCOVA) were used to compare group differences. Results indicated that early maturers were taller, heavier, and had greater strength, power, speed, and agility (p < 0.05). When controlling for age, height, and body mass, early maturers remained stronger, quicker, and more agile (p < 0.05). They were also more skillful in the speed shot shooting test (p < 0.05). Apart from tests of aerobic fitness, abdominal muscular strength and endurance, and lower body explosive power, maturity status was the primary contributor to the variance in the physical performance tests. Years of training was the primary contributor to the variance in the technical skills tests. Whilst physical performance was dependent on maturity status, technical skills were influenced by years of training. Since both biological maturation and years of training play an important role in basketball performance, we recommend that coaches consider the effects of these two confounders when recruiting and selecting youth basketballers.

Translation and cross-cultural adaptation of the International Trauma Questionnaire for use in Brazilian Portuguese.

BACKGROUND: The most recent editions of diagnostic manuals have proposed important modifications in posttraumatic stress disorder (PTSD) criteria. The International Trauma Questionnaire (ITQ) is the gold-standard measurement for assessing PTSD and complex PTSD in accordance with the model of the 11th International Classification of Diseases (ICD-11). OBJECTIVE: The aim of this study was to adapt the ITQ for the Brazilian context. DESIGN AND SETTING: The translation and cross-cultural adaptation of the ITQ for use in Brazilian Portuguese was performed in trauma research facilities in Porto Alegre, Rio de Janeiro and Belo Horizonte, Brazil. METHODS: The adaptation followed five steps: (1) translation; (2) committee synthesis; (3) experts' evaluation through the content validity index (CVI) and assessment of interrater agreement though kappa statistics; (4) comprehension test with clinical and community samples (n = 35); and (5) final back-translation and authors' evaluation. RESULTS: Two independent translations were conducted. While working on a synthesis of these translations, the committee proposed changes in six items to adapt idiomatic expressions or to achieve a more accurate technical fit. Both the expert judges' evaluation (CVI > 0.7; k > 0.55) and the pretest in the target population (mean comprehension > 3) indicated that the adapted items were adequate and comprehensible. The final back-translation was approved by the authors of the original instrument. CONCLUSION: ITQ in its Brazilian Portuguese version achieved satisfactory content validity, thus providing a tool for Brazilian research based on PTSD models of the ICD-11.

Translation and cross-cultural adaptation of the International Trauma Questionnaire for use in Brazilian Portuguese

ABSTRACT BACKGROUND: The most recent editions of diagnostic manuals have proposed important modifications in posttraumatic stress disorder (PTSD) criteria. The International Trauma Questionnaire (ITQ) is the gold-standard measurement for assessing PTSD and complex PTSD in accordance with the model of the 11th International Classification of Diseases (ICD-11). OBJECTIVE: The aim of this study was to adapt the ITQ for the Brazilian context. DESIGN AND SETTING: The translation and cross-cultural adaptation of the ITQ for use in Brazilian Portuguese was performed in trauma research facilities in Porto Alegre, Rio de Janeiro and Belo Horizonte, Brazil. METHODS: The adaptation followed five steps: (1) translation; (2) committee synthesis; (3) experts' evaluation through the content validity index (CVI) and assessment of interrater agreement though kappa statistics; (4) comprehension test with clinical and community samples (n = 35); and (5) final back-translation and authors' evaluation. RESULTS: Two independent translations were conducted. While working on a synthesis of these translations, the committee proposed changes in six items to adapt idiomatic expressions or to achieve a more accurate technical fit. Both the expert judges' evaluation (CVI > 0.7; k > 0.55) and the pretest in the target population (mean comprehension > 3) indicated that the adapted items were adequate and comprehensible. The final back-translation was approved by the authors of the original instrument. CONCLUSION: ITQ in its Brazilian Portuguese version achieved satisfactory content validity, thus providing a tool for Brazilian research based on PTSD models of the ICD-11.

Decreased expression of folate transport proteins in oral cancer.

OBJECTIVES: The purpose of this study was to assess the expression of the 3 major folate transporters-folate receptors (FRs), reduced folate carrier (RFC), and proton-coupled folate transporter (PCFT)-in oral squamous cell carcinoma (OSCC). We hypothesized that patterns of expression of folate transporters would be different in OSCC compared with normal oral epithelium. STUDY DESIGN: We used immunohistochemistry to examine the expression of FR, RFC, and PCFT in 15 primary specimens collected from patients with OSCC, 2 human cadaveric samples of OSCC, and 12 normal human cadaveric oral tissues from a medical gross anatomy laboratory. Possible correlations between the expression of each folate transporter and patients' clinical data were determined. RESULTS: All 3 folate transporters were highly expressed in normal oral epithelium. In contrast, OSCC samples generally demonstrated low expression of FR, RFC, and PCFT, with wide distribution in the invading cancer cells. There were no differences in folate transporter expression between OSCC samples collected from patients and from human cadavers. The lowest expression of FR and PCFT characterized less-differentiated tumors, and the lowest expression of RFC correlated with higher lymph node involvement. CONCLUSIONS: Human oral cancer samples expressed decreased amounts of all 3 major folate transport proteins compared with controls from normal cadaveric oral tissues.