Aberrant right posterior sectoral duct injury necessitating liver resection.

Aberrant insertion of the right posterior sectoral duct is a particularly hazardous variation of biliary anatomy which makes it prone to injury during laparoscopic cholecystectomy. Such injuries are challenging to manage, as multiple therapeutic options are available with no clear consensus in the literature for an optimal approach. Options include conservative management, intraoperative ligation of the injured duct, Roux-en-Y reconstruction and segmental liver resection. Most cases in the literature advocate for nonoperative management or hepaticojejunostomy. We present an unusual case of aberrant right posterior sectoral duct injury in which neither of these approaches was viable, necessitating a bi-segmental liver resection.

Age- and gender-specific variations of the epiphyseal tilt and epiphyseal angle in adolescents without hip pathology.

PURPOSE: To determine age-and gender-dependent variation of epiphyseal tilt and epiphyseal angle using CT in adolescents without hip pathology. METHODS: Pelvic CT scans were obtained in 132 adolescents for evaluation of abdominal pain. Radially oriented planes around the femoral neck were reformatted and the epiphyseal tilt and angle were measured in the anterior, anterosuperior and superior planes. Variations in the tilt angle and epiphyseal angle were assessed by age group from 12 to 18 years and gender by using a linear mixed model analysis. RESULTS: The epiphyseal tilt did not change (p = 0.97) with increasing age. Male patients exhibited smaller tilt angle in the anterosuperior plane (p = 0.003) but no difference was detected in the anterior (p = 0.17) or superior (p = 0.06) planes. The epiphyseal angle decreased with increasing age in the anterior (p = 0.03), anterosuperior (p = 0.001) and superior (p < 0.001) planes in male patients, with no variation in female patients (p = 0.92). Male patients had larger epiphyseal angles in the anterior (p = 0.02), anterosuperior (p < 0.001) and superior (p = 0.002) planes compared with female patients. CONCLUSION: We found no age-specific variations in the epiphyseal tilt and no difference in the epiphyseal tilt in male and female patients in the superior and anterior plane. The epiphyseal angle was smaller in female patients, however, the epiphyseal angle decreased with increasing age in male patients which corresponds to an increase in epiphyseal extension. The reference values reported in this study may serve as additional information in the evaluation of adolescents with hip pain and as reference for future studies investigating slipped capital femoral epiphysis and femoroacetabular impingement development. LEVEL OF EVIDENCE: Level III Diagnostic Study.

A student leadership model for promoting educational programs in organ donation and transplantation.

The global organ shortage is the strongest factor for the increase in transplant wait time and deaths on waitlists. Here we describe a model for involving high school students in education research around organ donation and transplantation and capitalize on the strength of a pre-existing educational program offered by the local organ procurement organization (OPO). While training in education research at Cleveland Clinic, a high school student embarked on a collaborative project with the local OPO. The project involved evaluating three educational programs, selecting the most appropriate program for administration at her school, coordinating with the student's school administration and teachers, administering an assessment tool for the effectiveness of the program, and analyzing the results. The local OPO program that was selected for implementation consisted of a video presentation entitled "Share your life, share your decision" prepared by the United States Health Resources and Services Administration (HRSA), lectures by invited speakers and an educational assessment (pre- and post-education). The assessment survey included 3 multiple choice and 7 true/false questions. Compared to the over 2500 programs administered in the last 5 years by the local OPO, this program had a higher volume of participation (n = 353 compared to an average of 150 students/day). Students correctly classified transplantation status of more organ and tissues post-education (P < .0001 for both). For 5 out of the 7 true/false questions, students correctly answered questions more frequently post-education (P ≤ .002 for all). This experience included for the first time a formal assessment of the program which will be utilized to address targeted areas for specific improvements. This student collaborative model of involving students in organ donation and transplantation related education research has the potential to promote and maximize the effectiveness of educational programs targeting their peers.

Can laypersons be trained to effectively deliver osteopathic manual therapy to patients with HIV?: a pilot study.

CONTEXT: Osteopathic manipulative treatment (OMT) may provide added benefits to standard human immunodeficiency virus (HIV) and AIDS treatments. However, lack of access to trained OMT providers is a potential barrier to the widespread use of OMT in the management of HIV and AIDS. OBJECTIVES: To determine the best time to measure the short-term impact of a brief OMT protocol on white blood cell counts in individuals with HIV and AIDS. Also, to explore recruiting and training laypersons to administer select osteopathic manual techniques. METHODS: Participants were HIV-positive men aged between 18 and 65 years who had not undergone antiretroviral therapy in the past 12 months, had CD4(+) lymphocyte counts of 200 to 700 cells/mm(3), and had viral load levels of less than 100,000 copies/mL. Participants were randomly assigned to an OMT group or a control group; those in the OMT group recruited a layperson for training in osteopathic manual therapy. Participants in the OMT group received a 15-minute OMT protocol consisting of myofascial release of the thoracic inlet, pectoral traction, rib raising, thoracic pump, and abdominal pump. Participants in the control group engaged in conversation with the researcher for 15 minutes. Between-group differences for each white blood cell type were examined at varying time intervals after the protocols. Laypersons were trained to administer thoracic and abdominal pump techniques. They were tested by multiple choice examinations and by an independent rater for fidelity of administration. RESULTS: Twenty-one participants met the eligibility criteria. Of those, 18 returned for their study visit (OMT group, n=9; control group, n=9). An optimal time interval for measurement of white blood cell changes across the 5 cell types was not determined. However, P values for the 30-minute interval were consistently below 0.18 for neutrophils, eosinophils, and monocytes. Nine laypersons were trained in osteopathic manual therapy, 5 of whom scored 100% on initial completion of the multiple-choice examination; the remaining 4 laypersons scored 80% on the first try and 100% on the second try. All laypersons appropriately administered the manual therapy protocol. CONCLUSION: It is feasible to recruit and train laypersons to administer selected osteopathic manual therapy techniques with fidelity. Longitudinal studies on this concept are needed to examine patient outcomes and to evaluate the retention and fidelity of laypersons over time.

Factors associated with favorable attitudes toward end-of-life planning.

Planning for end-of-life (EOL) care can result in better patient outcomes and lowered health care costs. We hypothesized that knowledge and experiences with EOL care would influence patients' EOL planning (i.e., health care decisions, hospice use). Using an observational, cross-sectional design, we recruited a community sample of 331 South Floridians aged 18 to 84 (M = 44 years, SD = 14.95) to complete a questionnaire examining knowledge and opinions on EOL issues. Regression analyses showed that prior knowledge of living wills and hospice services were associated with more favorable attitudes toward hospice care, preference for limited medical interventions at EOL, and more comfort in communicating about death and dying. Patient education on EOL care may increase hospice use, enhance EOL planning, and improve patient outcomes.

Survey of Attitudes and Practices of Osteopathic Primary Care Physicians Regarding Taking of Sexual Histories and HIV Screening.

CONTEXT: an estimated 252,000 to 312,000 individuals have undiagnosed human immunodeficiency virus (HIV) infection in the United States. To date, little has been known about osteopathic physicians' attitudes and practices regarding routine HIV testing. OBJECTIVES: to understand osteopathic primary care physicians' attitudes and practices toward HIV testing and sexual history taking and to examine factors associated with osteopathic physicians' recommendations of HIV testing at the initial patient visit. METHODS: a cross-sectional survey of osteopathic physicians was conducted at the 106th Annual Convention of the Florida Osteopathic Medical Association in February 2009. Survey participants were asked 36 questions about osteopathic physician and patient sociodemographic factors and osteopathic physician attitudes and office practices regarding HIV testing and sexual history taking. RESULTS: a total of 233 osteopathic physicians completed the survey, but only 160 respondents (69%) met inclusion criteria of working in primary care and spending more than 50% of their time with patients. Almost two-thirds of participants were men, 80% were white, and the age range was 28 to 83 years. Twenty-two percent of participants recommended HIV testing at the initial patient visit, and 18% recommended annual HIV testing for all patients. Eighty-seven percent obtained a separate consent form for HIV testing, and 19% included HIV testing in general consent forms. About two-thirds of participants recommended annual HIV testing for homosexual men. Three factors were associated with recommending HIV testing at the initial patient visit: (1) recommending an annual HIV test for sexually active patients (odds ratio [OR], 12.82; 95% confidence interval [CI], 3.97-41.67); (2) having an agree/strongly agree attitude toward HIV testing (OR, 5.59; 95% CI, 1.63-19.23); and (3) obtaining a general consent form that included permission for HIV testing (OR, 3.25; 95% CI, 1.07-9.90). CONCLUSION: osteopathic physicians who practice primary care medicine can play a crucial role in reducing the number of individuals with undiagnosed HIV infection. More concerted efforts are needed to help osteopathic physicians incorporate HIV testing as part of routine care for all patients.

Factors associated with risk for unprotected receptive and insertive anal intercourse in men aged 40 and older who have sex with men.

The frequency of HIV infection is increasing in men who have sex with men (MSM) aged 40 and older yet little is known about factors that influence their risky sexual behavior, such as sexual positioning. The goal of this study was to examine multi-level factors associated with unprotected receptive anal intercourse (URAI) and unprotected insertive anal intercourse (UIAI) in MSM aged 40 and older. A community-based sample of 802 self-identified MSM aged 40-94 years was recruited through targeted outreach from community venues (e.g., bars, social events) in South Florida and completed an anonymous pen-and-paper questionnaire. Logistic regression showed that younger age (i.e., aged 40-59; odds ratio [OR]=0.6; 95% confidence interval [CI]: 0.4, 0.9), HIV-positive status (OR=2.8; 95% CI: 1.9, 4.0), drug use (OR=2.6; 95% CI: 1.7, 3.7), a larger number of male sexual partners (OR=1.7; 95% CI: 1.3, 2.3), and lower scores on internalized homonegativity (OR=0.9; 95% CI: 1.0, 1.0) were associated with higher risk for URAI. Younger age (OR=0.4; 95% CI: 0.3, 0.6), HIV-positive status (OR=1.5; 95% CI: 1.0, 2.1), drug use (OR=1.6; 95% CI: 1.1, 22.3), Viagra use (OR=1.7; 95% CI: 1.2, 2.4), larger number of sexual partners (OR=2.1; 95% CI: 1.6, 2.9), and holding views more characterized by high optimism concerning the future (OR=1.1; 95% CI: 1.0, 1.1) were associated with higher risk for UIAI. These results provide useful information that may guide the development of tailored prevention interventions to reduce the growing rates of HIV among MSM aged 40 and older.

Stable isotope analysis of modern human hair collected from Asia (China, India, Mongolia, and Pakistan).

We report isotopic data (delta(2)H, delta(18)O n = 196; delta(13)C, delta(15)N n = 142; delta(34)S n = 85) from human hair and drinking water (delta(2)H, delta(18)O n = 67) collected across China, India, Mongolia, and Pakistan. Hair isotope ratios reflected the large environmental isotopic gradients and dietary differences. Geographic information was recorded in H and O and to a lesser extent, S isotopes. H and O data were entered into a recently developed model describing the relationship between the H and O isotope composition of human hair and drinking water in modern USA and pre-globalized populations. This has anthropological and forensic applications including reconstructing environment and diet in modern and ancient human hair. However, it has not been applied to a modern population outside of the USA, where we expect different diet. Relationships between H and O isotope ratios in drinking water and hair of modern human populations in Asia were different to both modern USA and pre-globalized populations. However, the Asian dataset was closer to the modern USA than to pre-globalized populations. Model parameters suggested slightly higher consumption of locally produced foods in our sampled population than modern USA residents, but lower than pre-globalized populations. The degree of in vivo amino acid synthesis was comparable to both the modern USA and pre-globalized populations. C isotope ratios reflected the predominantly C(3)-based regional agriculture and C(4) consumption in northern China. C, N, and S isotope ratios supported marine food consumption in some coastal locales. N isotope ratios suggested a relatively low consumption of animal-derived products compared to western populations.

Drug use and Hispanic men who have sex with men in South Florida: implications for intervention development.

Despite continued high HIV risk among Hispanic men who have sex with men (HMSM), culturally tailored, theoretically based interventions have yet to be developed and tested. As a first step toward intervention development, we collected quantitative and qualitative data on sociocultural and psychological factors associated with drug use and risky sex among 566 HMSM recruited from community and Internet venues. Participants reported high rates of drug use (43%), unprotected anal sex (45%), and multiple sex partners (median 4) in the past 6 months. In multivariate analyses, use of drugs was associated with HIV seropositivity, less orientation to the Hispanic community, stronger attachment to the gay community, lower levels of homophobia, higher numbers of sex partners and more unprotected anal sex. The need for acceptance and desire to please partners emerged as core drivers of HIV risk in the qualitative data. Findings were used to guide development of Proyecto SOL, a theoretically grounded intervention that targets core determinants of HIV risk, builds on protective cultural influences, and strengthens positive social connections.

Culturally competent methods to promote organ donation rates among African-Americans using venues of the Bureau of Motor Vehicles.

BACKGROUND: The diversity of the nation is one of society's greatest assets, but this feature is overshadowed by the disproportionate burden of disease that exists among America's minorities. Evidence of the disparate health status has been documented in low life expectancy, cancer, diabetes, cardiovascular, and kidney disease as well as a plethora of disorders that necessitate organ transplantation. Many minorities have been reluctant to register to become organ donors. This circumstance can be alleviated by educating the public regarding the necessity of organ transplantation. We have developed a "unique" collaborative outreach program designed to promote acceptance of organ donation in African-Americans (AAs). Our outreach curriculum at Bureau of Motor Vehicles (BMV) has resulted in increased registrations and awareness regarding the need and positive perceptions toward donation. METHODS: We developed a culturally sensitive outreach program: cultural sensitivity indicates how culture has the ability to influence communication between patients and health providers. An "Outreach Promotional Contest" was strategically targeted toward 28 Ohio BMVs to promote and assist in an outreach educational program regarding organ donation/registry. RESULTS: The consequence/results has been an increase of 3.4% in the BMV locations. The one BMV, with the highest increase was attended predominantly by AAs which moreover, won first place in the contest (6.425%; P < .05). CONCLUSION: To increase the number of people willing to register, we believe that both community education regarding the need and importance, as well as culturally sensitive promotion of organ donation, is the best way to increase organ donor registries particularly among minority populations.

HIV risk behaviors of Latin American and Caribbean men who have sex with men in Miami, Florida, USA.

OBJECTIVE: The goal of this study is to describe the sexual practices, drug use behaviors, psychosocial factors, and predictors of unprotected anal intercourse (UAI) in a sample of Hispanic men who have sex with men (MSM) born in Latin American and Caribbean (LAC) countries who currently reside in Miami-Dade County, Florida. METHODS: Hispanic MSM (N = 566) recruited from community and Internet venues completed a computer-assisted self-interview assessing sociodemographic factors, drug use, sexual behaviors, and psychosocial factors. We focused on the 470 men who were born in LAC countries, including Puerto Rico. We first examined separately, by country of origin, the sexual practices, drug use behaviors, and psychosocial factors of the sample. We then collapsed the groups and examined the factors associated with UAI in the previous 6 months for the entire sample of Hispanic MSM from LAC countries. RESULTS: In the previous 6 months, 44% of the sample engaged in UAI, and 41% used club drugs. At the multivariate level, psychological distress, higher number of sexual partners, club drug use, HIV-positive status at the time of immigration, and greater orientation to American culture were significantly associated with UAI in the previous 6 months. CONCLUSION: Many MSM born in LAC countries engage in HIV-related risk behaviors in the AIDS epicenter of Miami-Dade County, Florida. Culturally appropriate interventions should address these risk behaviors in this underserved population.

HIV risk behaviors of Latin American and Caribbean men who have sex with men in Miami, Florida, USA

OBJECTIVE: The goal of this study is to describe the sexual practices, drug use behaviors, psychosocial factors, and predictors of unprotected anal intercourse (UAI) in a sample of Hispanic men who have sex with men (MSM) born in Latin American and Caribbean (LAC) countries who currently reside in Miami-Dade County, Florida. METHODS: Hispanic MSM (N = 566) recruited from community and Internet venues completed a computer-assisted self-interview assessing sociodemographic factors, drug use, sexual behaviors, and psychosocial factors. We focused on the 470 men who were born in LAC countries, including Puerto Rico. We first examined separately, by country of origin, the sexual practices, drug use behaviors, and psychosocial factors of the sample. We then collapsed the groups and examined the factors associated with UAI in the previous 6 months for the entire sample of Hispanic MSM from LAC countries. RESULTS: In the previous 6 months, 44 percent of the sample engaged in UAI, and 41 percent used club drugs. At the multivariate level, psychological distress, higher number of sexual partners, club drug use, HIV-positive status at the time of immigration, and greater orientation to American culture were significantly associated with UAI in the previous 6 months. CONCLUSIONS: Many MSM born in LAC countries engage in HIV-related risk behaviors in the AIDS epicenter of Miami-Dade County, Florida. Culturally appropriate interventions should address these risk behaviors in this underserved population.

HIV risk behaviors of Latin American and Caribbean men who have sex with men in Miami, Florida, USA / Comportamientos de riesgo de infección por el VIH en hombres latinoamericanos y caribeños que tienen sexo con hombres en Miami, Florida, EUA

OBJECTIVE: The goal of this study is to describe the sexual practices, drug use behaviors, psychosocial factors, and predictors of unprotected anal intercourse (UAI) in a sample of Hispanic men who have sex with men (MSM) born in Latin American and Caribbean (LAC) countries who currently reside in Miami-Dade County, Florida. METHODS: Hispanic MSM (N = 566) recruited from community and Internet venues completed a computer-assisted self-interview assessing sociodemographic factors, drug use, sexual behaviors, and psychosocial factors. We focused on the 470 men who were born in LAC countries, including Puerto Rico. We first examined separately, by country of origin, the sexual practices, drug use behaviors, and psychosocial factors of the sample. We then collapsed the groups and examined the factors associated with UAI in the previous 6 months for the entire sample of Hispanic MSM from LAC countries. RESULTS: In the previous 6 months, 44 percent of the sample engaged in UAI, and 41 percent used club drugs. At the multivariate level, psychological distress, higher number of sexual partners, club drug use, HIV-positive status at the time of immigration, and greater orientation to American culture were significantly associated with UAI in the previous 6 months. CONCLUSIONS: Many MSM born in LAC countries engage in HIV-related risk behaviors in the AIDS epicenter of Miami-Dade County, Florida. Culturally appropriate interventions should address these risk behaviors in this underserved population.

OBJETIVO: Describir las prácticas sexuales, el consumo de drogas y los factores psicosociales y de predicción del coito anal sin protección (CASP), en una muestra de hombres nacidos en América Latina y el Caribe (ALC) residentes actualmente en el Condado de Miami-Dade, Florida, que tienen sexo con hombres. MÉTODOS: En total, 566 hispanos que tienen sexo con hombres (HSH), captados en la comunidad y sitios de Internet, completaron una encuesta autoaplicada por computadora que abordaba los factores socioeconómicos, el consumo de drogas, el comportamiento sexual y los factores psicológicos. El estudio se centró en 470 hombres nacidos en ALC, incluido Puerto Rico. La muestra se analizó por país de origen, prácticas sexuales, consumo de drogas y factores psicológicos. Luego se unieron los grupos y se analizaron los factores asociados con el CASP en los 6 meses previos en toda la muestra. RESULTADOS: En los 6 meses previos, 44 por ciento de la muestra tuvo CASP y 41 por ciento consumió drogas de las llamadas recreativas. Según el análisis multifactorial, los factores asociados significativamente con el CASP en los 6 meses previos fueron: los problemas psicológicos, el mayor número de parejas sexuales, el consumo de drogas recreacionales, la positividad al VIH en el momento en que inmigró y el mayor grado de orientación hacia la cultura estadounidense. CONCLUSIONES: Muchos HSH nacidos en ALC incurren en comportamientos de riesgo de infección por el VIH en el epicentro de sida del Condado de Miami-Dade, Florida. Se deben aplicar intervenciones culturalmente apropiadas para combatir estos comportamientos de riesgo en la población marginada estudiada.

An evaluation of the value of group education in recently diagnosed diabetes mellitus.

Diabetic patients have a 12% to 25% lifetime risk of developing foot complications leading to significant morbidity and mortality. The objective of this study was to assess the effectiveness of group education in improving patient awareness of foot care. The authors evaluated the effect of group size and areas in which knowledge seemed to be most affected. Patients attending a 2-hour teaching session between November 2005 and March 2006 were recruited. Patients filled in an 18-part questionnaire before and after the teaching session to assess knowledge. Fifty-nine patients recently diagnosed with diabetes mellitus or foot complications were recruited for 7 sessions. Analysis of the data showed a statistically significant improvement in foot care knowledge after the teaching session compared with before (69% to 85%, P < .001). Patients in the smaller group (n < 10) had significantly higher scores compared with the bigger groups (n > 10; P < .025). These data show the benefit of group education about foot care for patients with diabetes. Smaller groups benefited more than larger ones did, which could be attributed to the sizes allowing for better interaction between the tutor and patient. As patient knowledge is variable from individual to individual, smaller teaching sessions may allow patients to address specific concerns.

Crystal methamphetamine: a source of added sexual risk for Hispanic men who have sex with men?

OBJECTIVES: To determine whether use of crystal methamphetamine increases HIV risk behaviors beyond the risk associated with use of other recreational drugs among Hispanic men who have sex with men (HMSM). DESIGN: We compared the sexual behaviors and psychosocial characteristics of non-recreational drug users (non-users), recreational drug users who did not use crystal (non-crystal drug users), and recreational drug users who used crystal (crystal users). METHODS: We recruited 294 HMSM from Internet and 272 from community venues. Eligible men completed an ACASI to assess socio-demographic factors, drug use, sexual behaviors and psychosocial factors and received 50 dollars. RESULTS: In the multivariate model, crystal users were more likely than non-crystal drug users to have lower Hispanicism, higher attachment to the gay community, and history of suicide attempts. Crystal users were not significantly different from non-crystal drug users in number of sex partners; however, differences in unprotected receptive anal sex approached significance. CONCLUSIONS: The additional risk of crystal above that of other recreational drugs needs to be disentangled from those associated with poly-drug use. Our data suggest that it may depend on how one defines risky sexual behavior and is influenced by psychological, physiologic and social factors.

Cruising in cyber space: comparing Internet chat room versus community venues for recruiting Hispanic men who have sex with men to participate in prevention studies.

Difficulties with recruitment of hidden populations, such as Hispanic men who have sex with men (MSM), have hampered HIV prevention research, leading researchers to explore alternative recruitment modalities such as the Internet. In this paper, we compare the efficiency and cost of recruiting HMSM from Internet chat rooms versus community venues and examine the differences between participants recruited from each type of venue. Internet recruitment was more efficient and somewhat less costly than community recruitment. Although the two groups were comparable in most demographic factors and HIV risk behaviors, Internet recruits were more likely to be bisexual, more likely to be HIV seropositive, had a higher level of education, and reported higher levels of psychological distress and lower levels of gay community attachment. Implications of our findings for using Internet chatrooms as recruitment venues are discussed.

Low-income African American women's attempts to convince their main partner to use condoms.

In this cross-sectional study the authors examine condom use attempts and condom use among 305 high-risk, low-income African American women who reported having a main partner. Women who had recently attempted to convince their main partner to use condoms were almost 10 times more likely to have recently used condoms with their partner than women who had not made an attempt. Among the subsample of 116 women who had recently made a condom use attempt with their main partner, having a history of childhood abuse and having one's main partner raise infidelity questions in response to the condom use attempt were negatively associated with recent condom use with this partner. Findings provide initial insights into the importance of women's condom use attempts, as well as subgroups of women who may encounter special challenges convincing their main partner to use condoms.

Excision of visual cortex does not affect the facilitatory and inhibitory effects of a light flash prepulse on the acoustic startle reflex in the rat.

We studied the inhibitory (PPI) and facilitatory (PPF) behavioural effects of brief light flashes presented as prepulses just prior to the acoustic startle reflex (ASR) in intact rats and in rats that had a bilateral excision of visual cortex (VC). The VC-lesioned and control groups (n=5, 5) were near identical in PPF for flashes presented 5-20 ms before the ASR and near identical in PPI for flashes presented 60 ms before the ASR. These findings differ from those of a case report of a human patient following occipital cortex resection, for whom light flashes failed to produce either acoustic startle PPF or PPI if the flash were presented to the portion of the visual field in which she could not see; they differ also from data obtained in functionally decorticate rats, for which a light flash produced no startle PPI, but instead a late-appearing exaggerated PPF. In the present experiment the lesion was restricted to VC, while in contrast the occipital resection in the human patient included posterior areas of the parietal and temporal lobe, and functional decortication in the rat disengaged the entire cortex. The greater extent of these two effective surgical procedures may have been responsible for their greater behavioural effects; otherwise, the complete loss of reflex control by photic stimulation in the human patient but not in the rat may reflect the greater functional importance and anatomical complexity of the VC in humans.