Evaluation of a training programme for Pharmacist Independent Prescribers in a care home medicine management intervention.

BACKGROUND: The provision of independent prescribing rights for United Kingdom (UK) pharmacists has enabled them to prescribe within their area of competence. The aim of this study was to evaluate an evidence-based training programme designed to prepare Pharmacist Independent Prescribers (PIPs) to safely and effectively assume responsibility for pharmaceutical care of older people in care homes in the UK, within a randomised controlled trial. METHODS: The training and competency assessment process included two training days, professional development planning against a bespoke competency framework, mentor support, and a viva with an independent General Practitioner (GP). Data on the PIPs' perceptions of the training were collected through evaluation forms immediately after the training days and through online questionnaires and interviews after delivery of the 6-month intervention. Using a mixed method approach each data set was analysed separately then triangulated providing a detailed evaluation of the process. Kaufman's Model of Learning Evaluation guided interpretations. RESULTS: All 25 PIPs who received the training completed an evaluation form (N = 25). Post-intervention questionnaires were completed by 16 PIPs and 14 PIPs took part in interviews. PIPs reported the training days and mentorship enabled them to develop a personalised portfolio of competence in preparation for discussion during a viva with an independent GP. Contact with the mentor reduced as PIPs gained confidence in their role. PIPs applied their new learning throughout the delivery of the intervention leading to perceived improvements in residents' quality of life and medicines management. A few PIPs reported that developing a portfolio of competence was time intensive, and that further training on leadership skills would have been beneficial. CONCLUSIONS: The bespoke training programme was fit for purpose. Mentorship and competency assessment were resource intensive but appropriate. An additional benefit was that many PIPs reported professional growth beyond the requirement of the study. TRIAL REGISTRATION: The definitive RCT was registered with the ISRCTN registry (registration number ISRCTN 17,847,169 ).

Laboratory Modeling of SARS-CoV-2 Exposure Reduction Through Physically Distanced Seating in Aircraft Cabins Using Bacteriophage Aerosol - November 2020.

Aircraft can hold large numbers of persons in close proximity for long periods, which can increase the risk for transmission of infectious disease.* Current CDC guidelines recommend against travel for persons who have not been vaccinated against COVID-19, and a January 2021 CDC order requires masking for all persons while on airplanes.†,§ Research suggests that seating proximity on aircraft is associated with increased risk for infection with SARS-CoV-2, the virus that causes COVID-19 (1,2). However, studies quantifying the benefit of specific distancing strategies to prevent transmission, such as keeping aircraft cabin middle seats vacant, are limited. Using bacteriophage MS2 virus as a surrogate for airborne SARS-CoV-2, CDC and Kansas State University (KSU) modeled the relationship between SARS-CoV-2 exposure and aircraft seating proximity, including full occupancy and vacant middle seat occupancy scenarios. Compared with exposures in full occupancy scenarios, relative exposure in vacant middle seat scenarios was reduced by 23% to 57% depending upon the modeling approach. A 23% exposure reduction was observed for a single passenger who was in the same row and two seats away from the SARS-COV-2 source, rather than in an adjacent middle seat. When quantifying exposure reduction to a full 120-passenger cabin rather than to a single person, exposure reductions ranging from 35.0% to 39.4% were predicted. A 57% exposure reduction was observed under the vacant middle seat condition in a scenario involving a three-row section that contained a mix of SARS-CoV-2 sources and other passengers. Based on this laboratory model, a vacant middle seat reduces risk for exposure to SARS-CoV-2 from nearby passengers. These data suggest that increasing physical distance between passengers and lowering passenger density could help reduce potential COVID-19 exposures during air travel. Physical distancing of airplane passengers, including through policies such as middle seat vacancy, could provide additional reductions in SARS-CoV-2 exposure risk.

The Role of Sulfur Dioxide in Stratospheric Aerosol Formation Evaluated Using In-Situ Measurements in the Tropical Lower Stratosphere.

Stratospheric aerosols (SAs) are a variable component of the Earth's albedo that may be intentionally enhanced in the future to offset greenhouse gases (geoengineering). The role of tropospheric-sourced sulfur dioxide (SO2) in maintaining background SAs has been debated for decades without in-situ measurements of SO2 at the tropical tropopause to inform this issue. Here we clarify the role of SO2 in maintaining SAs by using new in-situ SO2 measurements to evaluate climate models and satellite retrievals. We then use the observed tropical tropopause SO2 mixing ratios to estimate the global flux of SO2 across the tropical tropopause. These analyses show that the tropopause background SO2 is about 5 times smaller than reported by the average satellite observations that have been used recently to test atmospheric models. This shifts the view of SO2 as a dominant source of SAs to a near-negligible one, possibly revealing a significant gap in the SA budget.

Improving patient outcomes in fibrous dysplasia/McCune-Albright syndrome: an international multidisciplinary workshop to inform an international partnership.

To develop consensus on improving the management of patients, we convened an international workshop involving patients, clinicians, and researchers. Key findings included the diagnostic delay and variability in subsequent management with agreement to develop an international natural history study. We now invite other stakeholders to join the partnership. PURPOSE: The aim of this study was develop a consensus on how to improve the management of patients with fibrous dysplasia and prioritize areas for research METHODS: An international workshop was held over 3 days involving patients, clinicians, and researchers. Each day had a combination of formal presentations and facilitated discussions that focused on clinical pathways and research. RESULTS: The patient workshop day highlighted the variability of patients' experience in getting a diagnosis, the knowledge of general clinical staff, and understanding long-term outcomes. The research workshop prioritized collaborations that improved understanding of the contemporary natural history of fibrous dysplasia/McCune-Albright syndrome (FD/MAS). The clinical workshop outlined the key issues around diagnostics, assessment of severity, treatment and monitoring of patients. CONCLUSIONS: In spite of advances in understanding the genetic and molecular underpinnings of fibrous dysplasia/McCune-Albright syndrome, clinical management remains a challenge. From the workshop, a consensus was reached to create an international, multi-stakeholder partnership to advance research and clinical care in FD/MAS. We invite other stakeholders to join the partnership.

The RUDY study platform - a novel approach to patient driven research in rare musculoskeletal diseases.

BACKGROUND: Research into rare diseases is becoming more common, with recognition of the significant diagnostic and therapeutic care gaps. Registries are considered a key research methodology to address rare diseases. This report describes the structure of the Rare UK Diseases Study (RUDY) platform that aims to improve research processes and address many of the challenges of carrying out rare musculoskeletal disease research. RUDY is an internet-based platform with online registration, initial verbal consent, online capture of patient reported outcome measures and events within a dynamic consent framework. The database structure, security and governance framework are described. RESULTS: There have been 380 participants recruited into RUDY with completed questionnaire rates in excess of 50 %. There has been one withdrawal and two participants have amended their consent options. CONCLUSIONS: The strengths of RUDY include low burden for the clinical team, low research administration costs with high participant recruitment and ease of data collection and access. This platform has the potential to be used as the model for other rare diseases globally.

Multimodal MRI characterization of experimental subarachnoid hemorrhage.

Subarachnoid hemorrhage (SAH) is associated with significant morbidity and mortality. We implemented an in-scanner rat model of mild SAH in which blood or vehicle was injected into the cistern magna, and applied multimodal MRI to study the brain prior to, immediately after (5min to 4h), and upto 7days after SAH. Vehicle injection did not change arterial lumen diameter, apparent diffusion coefficient (ADC), T2, venous signal, vascular reactivity to hypercapnia, or foot-fault scores, but mildly reduce cerebral blood flow (CBF) up to 4h, and open-field activity up to 7days post injection. By contrast, blood injection caused: (i) vasospasm 30min after SAH but not thereafter, (ii) venous abnormalities at 3h and 2days, delayed relative to vasospasm, (iii) reduced basal CBF and to hypercapnia 1-4h but not thereafter, (iv) reduced ADC immediately after SAH but no ADC and T2 changes on days 2 and 7, and (v) reduced open-field activities in both SAH and vehicle animals, but no significant differences in open-field activities and foot-fault tests between groups. Mild SAH exhibited transient and mild hemodynamic disturbances and diffusion changes, but did not show apparent ischemic brain injury nor functional deficits.

The effect of mild traumatic brain injury on peripheral nervous system pathology in wild-type mice and the G93A mutant mouse model of motor neuron disease.

Traumatic brain injury (TBI) is associated with a risk of neurodegenerative disease. Some suggest a link between TBI and motor neuron disease (MND), including amyotrophic lateral sclerosis (ALS). To investigate the potential mechanisms linking TBI to MND, we measured motor function and neuropathology following mild-TBI in wild-type and a transgenic model of ALS, G93A mutant mice. Mild-TBI did not alter the lifespan of G93A mice or age of onset; however, rotarod performance was impaired in G93A verses wild-type mice. Grip strength was reduced only in G93A mice after mild-TBI. Increased electromyography (EMG) abnormalities and markers of denervation (AchR, Runx1) indicate that mild-TBI may result in peripheral effects that are exaggerated in G93A mice. Markers of inflammation (cell edema, astrogliosis and microgliosis) were detected at 24 and 72h in the brain and spinal cord in wild-type and G93A mice. Levels of F2-isoprostanes, a marker of oxidative stress, were increased in the spinal cord 24h post mild-TBI in wild-type mice but were not affected by TBI in G93A mice. In summary, our data demonstrate that mild-TBI induces inflammation and oxidative stress and negatively impacts muscle denervation and motor performance, suggesting mild-TBI can potentiate motor neuron pathology and influence the development of MND in mice.

Awakening professionals' critical awareness of health literacy issues within a francophone linguistic-minority population in Ontario.

INTRODUCTION: We carried out a qualitative evaluation of immediate learning and attitudinal change among health care and social services professionals who attended a workshop promoting critical reflection about health literacy among linguistic-minority Franco-Ontarians. METHODS: The study involved 41 francophone health care and social services professionals. The workshop facilitator used evocative objects to elicit reflection on health literacy. Data sources were audio-recordings of group discussions and feedback forms completed by participants. RESULTS: The study found that the workshop awakened participants' awareness of health literacy and stimulated them to promote health literacy in their professional practice. The workshop also broadened participants' vision of health literacy as a social determinant of health that interacts synergistically with culture, age, immigration status, social support, and socioeconomic status. CONCLUSION: Professionals expressed their awakened awareness of health literacy as collective accountability. This corroborates our claim that critical pedagogy applied to in-service education effectively stimulates professionals' awareness of their potential to change their practice and work environment.

TITRE: Susciter chez les professionnels une prise de conscience critique des enjeux liés à la littératie en santé pour des francophones en situation de minorité linguistique en Ontario. INTRODUCTION: Nous avons procédé à une évaluation qualitative des changements immédiats sur les plans de l'apprentissage et de l'attitude chez des professionnels de la santé et des services sociaux ayant participé à un atelier visant à susciter une réflexion critique sur la littératie en santé des Franco-Ontariens en situation de minorité linguistique. MÉTHODOLOGIE: L'étude a été réalisée auprès de 41 professionnels francophones de la santé et des services sociaux. L'animatrice de l'atelier a utilisé des objets évocateurs pour susciter la réflexion sur la littératie en santé. Les sources de données étaient les enregistrements audio des discussions de groupes et les formulaires de rétroaction remplis par les participants. RÉSULTATS: L'étude a révélé que l'atelier avait suscité chez les participants une prise de conscience à propos de la littératie en santé et les avait incités à promouvoir la littératie en santé dans leur pratique professionnelle. L'atelier a aussi élargi la vision de la littératie en santé qu'avaient les participants à sa dimension de déterminant social de la santé qui agit en synergie avec la culture, l'âge, le statut à l'égard de l'immigration, le soutien social et le statut socioéconomique. CONCLUSION: Les professionnels ont estimé que la prise de conscience des problèmes de littératie en santé relevait d'une responsabilité collective. Cela corrobore notre hypothèse selon laquelle une pédagogie critique appliquée à la formation continue stimule chez les professionnels la prise de conscience de leur capacité à vouloir changer leur pratique et leur milieu de travail.

The recovery of semen from bathwater using the Evidence Recovery System (ERS).

Sexual offences are under-reported and ascertaining accurate offence numbers is difficult. Any methods which could increase the ability to obtain biological evidence or reduce the additional distress associated with reporting a sexual offence may result in an increase in reporting this crime type. The Evidence Recovery System (ERS) is designed to collect trace evidence, including hairs, fibres and biological evidence, from bath or shower water in a non-invasive manner. Initially, samples of semen were placed in baths filled with water, and washing was simulated using a range of body wash products. The water was then drained through the ERS before its filters were subjected to acid phosphatase testing and haematoxylin and eosin staining of spermatozoa. Recovered spermatozoa were then graded accordingly. Following this, the experiment was repeated with the addition of dirt/dust particulates during the washing stage, to simulate recovery of biological evidence in a more realistic environment. The results showed that spermatozoa considered 'easy to find' could regularly be obtained from bathwater using the ERS. It appeared that this recovery was not affected by the presence of different body wash products. When dust/dirt particles were added, the number of spermatozoa recovered increased at two of the evidence collection stages. The difference in recovery was considered to be statistically significant. This study provides evidence to suggest the feasibility of use of the ERS as a method to collect semen evidence from individuals subjected to sexual offences. The recovery of spermatozoa does not appear to be affected by the presence of a body wash, but does appear to be improved when skin cells, hair and other debris are transferred into the water, as would be likely during a bath/shower. Further to this, the possibility of obtaining spermatozoa from the home bath or shower of a victim following a post-offence bathing experience is implied.

Airborne exposure patterns from a passenger source in aircraft cabins.

Airflow is a critical factor that influences air quality, airborne contaminant distribution, and disease transmission in commercial airliner cabins. The general aircraft-cabin air-contaminant transport effect model seeks to build exposure-spatial relationships between contaminant sources and receptors, quantify the uncertainty, and provide a platform for incorporation of data from a variety of studies. Knowledge of infection risk to flight crews and passengers is needed to form a coherent response to an unfolding epidemic, and infection risk may have an airborne pathogen exposure component. The general aircraf-tcabin air-contaminant transport effect model was applied to datasets from the University of Illinois and Kansas State University and also to case study information from a flight with probable severe acute respiratory syndrome transmission. Data were fit to regression curves, where the dependent variable was contaminant concentration (normalized for source strength and ventilation rate), and the independent variable was distance between source and measurement locations. The data-driven model showed exposure to viable small droplets and post-evaporation nuclei at a source distance of several rows in a mock-up of a twin-aisle airliner with seven seats per row. Similar behavior was observed in tracer gas, particle experiments, and flight infection data for severe acute respiratory syndrome. The study supports the airborne pathway as part of the matrix of possible disease transmission modes in aircraft cabins.

Organic aerosol formation downwind from the Deepwater Horizon oil spill.

A large fraction of atmospheric aerosols are derived from organic compounds with various volatilities. A National Oceanic and Atmospheric Administration (NOAA) WP-3D research aircraft made airborne measurements of the gaseous and aerosol composition of air over the Deepwater Horizon (DWH) oil spill in the Gulf of Mexico that occurred from April to August 2010. A narrow plume of hydrocarbons was observed downwind of DWH that is attributed to the evaporation of fresh oil on the sea surface. A much wider plume with high concentrations of organic aerosol (>25 micrograms per cubic meter) was attributed to the formation of secondary organic aerosol (SOA) from unmeasured, less volatile hydrocarbons that were emitted from a wider area around DWH. These observations provide direct and compelling evidence for the importance of formation of SOA from less volatile hydrocarbons.

Surgical correction of pectus excavatum. How did we get here? Where are we going?

The currently applied techniques recommended for the repair of pectus excavatum anomalies are discussed, set against a historical review of early clinical studies and surgical interventions. The issues of the future direction pectus excavatum surgery may take are analyzed in detail, with the reviewer expressing reservations in connection with the recent trend to closed repair and concern over the potential for serious complications associated with the application of this technique.

A prelude to Fontan.

In the decades preceding the Fontan operation, there was an intensive experimental and clinical quest to bypass the right heart. Whereas right heart bypass was successfully achieved in animal experiments, clinically only partial bypass (superior cava-right pulmonary artery anastomosis) was applied successfully. This intensive experimental and clinical activity provided the background for the Fontan operation.

Effects of chronic prenatal ethanol exposure on mitochondrial glutathione and 8-iso-prostaglandin F2alpha concentrations in the hippocampus of the perinatal guinea pig.

It is hypothesised that oxidative stress is a key mechanism of ethanol neurobehavioural teratogenicity, resulting in altered endogenous antioxidant status and increased membrane lipid peroxidation in the hippocampus of chronic prenatal ethanol exposure (CPEE) offspring. To test this hypothesis, timed pregnant guinea-pigs (term, approximately gestational day (GD) 68) received chronic daily oral administration of (i) 4 g ethanol kg(-1) maternal bodyweight, (ii) isocaloric sucrose with pair feeding, or (iii) water. At GD 65 (term fetus) and postnatal day (PD) 0 (neonate), individual offspring were killed, the brain was excised and the hippocampi were dissected. Glutathione (GSH) concentration was measured in the cytosolic and mitochondrial fractions of hippocampal homogenate. The occurrence of lipid peroxidation was determined by measuring the concentration of 8-iso-prostaglandin F2+/- (8-iso-PGF2+/-). There was CPEE-induced decreased brain weight and hippocampal weight at GD 65 and PD 0, decreased mitochondrial GSH concentration in the hippocampus at PD 0, with no change in mitochondrial GSH concentration at GD 65 or cytosolic GSH concentration at GD 65 or PD 0, and no change in mitochondrial or whole-homogenate 8-iso-PGF2+/- concentration in the hippocampus at GD 65 or PD 0. The data demonstrate that CPEE produces selective mitochondrial dysfunction in the hippocampus of the neonatal guinea-pig, involving GSH depletion.

Attention-deficit hyperactivity disorder and fluctuating asymmetry in another college sample.

Attention deficit/hyperactivity disorder (AD/HD) represents a developmental lag that may be reflected in fluctuating asymmetry (FA), i.e., differences from perfect symmetry in traits that display bilateral symmetry. Burton et al. (2003 Am. J. Hum. Biol. 15:601-619) found a statistical trend for FA to increase (as dermatoglyphic index or as total index) as the behavioral measure for AD/HDness (Rasch logit values derived from the Wender Utah Rating Scale, or WURS) increased in males but not in females. The objective here was to do a similar study in an independently collected sample of college students (n = 222; 61 male, 161 female) not selected for AD/HD, looking at FA vs. symptoms for AD/HD based on Rasch versions of responses to the Diagnostic and Statistical Manual of Mental Disorders (DSM IV) (Barkley and Murphy 1998 Attention-Deficit Hyperactivity Disorder, New York: Guilford Press, p. 95-96) and the more comparable shortened WURS. FAs were lowest for body and ear height, and highest for eye width and nose width, and ranged from 0.01 +/- 0.001 (mean +/- SE) for foot and ankle widths to 0.13 +/- 0.01 in eye and nose widths for both sexes; the sexes did not differ significantly. Males displayed higher AD/HD symptom rates overall. There was a significant correlation between body FA and the WURS measure in females after Bonferroni correction (P = 0.002, r(2) = 0.058). Thus, AD/HD symptoms levels increased with an increase in body FA in female college students not selected for AD/HD.

Incidence of student exposures to blood and body fluids and postexposure management protocols in dental hygiene programs.

PURPOSE: The purpose of this study was to determine the incidence of occupational exposures to blood or body fluids reported in dental hygiene students from 1996 to 1998 as well as postexposure management protocols used in dental hygiene programs. METHODS: A 23-item, self-designed questionnaire was sent to the 214 dental hygiene programs that were accredited in 1996. Sixty-seven percent (143) of the sample completed the questionnaire. Data were analyzed using descriptive statistics, the Mann Whitney-U test, chi-square, and the Freedman test. RESULTS: Over the three-year evaluation period, 687 total occupational exposures were reported, with dental hygiene schools averaging less than 1.5 exposures per year. The overall exposure rate was 1.8 per 100 first year students and 5.1 per 100 second year students, with second year students experiencing a significantly greater number of exposures than first year students (P = .000). The vast majority (78%) of the exposures occurred as a result of an instrument puncture. In regards to postexposure management and protocols, more than one-fourth of the respondents reported that they did not have a policy for immediate postexposure management. The majority of the schools do not report on the amount of fluid or material involved, whether the source material contained HIV, depth of the injury, estimated volume of material involved, condition of skin, or duration of contact. CONCLUSIONS: Results of this study reveal that dental hygiene students are at a relatively low risk for occupational exposures to blood and body fluids, although the risk does increase as they progress from the first to second year. Additionally, many schools of dental hygiene should review current protocols for postexposure management and reporting in order to ensure they are complying with current standards for the management of occupational exposures.

Applying a cultural models approach to American Indian substance dependency research.

The cognitive anthropological method of deriving cultural models from ethnographic discourse analysis is illustrated in relation to case studies yielding nativistic insights regarding American Indian substance dependency and recovery. Discussion focuses on the broader applicability and local community relevance of incorporating cultural models directly into the design and implementation of prevention and intervention programs. Such an approach may benefit local community cultural revitalization efforts while enhancing the cultural relevance and effectiveness of substance abuse programs.

Apoptotic cell death and fertility in three unilateral cryptorchid rat models.

Three rat strains have been studied, using a sensitive apoptotic detection method for germ-cell degeneration, to resolve the controversy regarding the effect of cryptorchidism on the contralateral descended testis (CDT). Sprague Dawley and Buffalo rats were made cryptorchid by operation at 20-22 days of age, while trans-scrotal (T-S) rats were a congenitally unilateral cryptorchid strain. Sham operated rats or normal T-S littermates were used as controls. Experiments were performed over a period ranging from 2 weeks to 18 months. Testis weight was assayed, as was the detection of apoptosis by agarose gel laddering and immunohistochemistry by using the TUNEL method. Labeled cells in 150 cross-sectioned testis tubules were counted on the TUNEL stained slides and the mean number of labeled cells per tubule was calculated. Paternity studies on Sprague Dawley and T-S rats were carried out at 12 and 24 weeks of age to assess fertility by the resultant number of pregnancies and litter sizes. Both Sprague Dawley and T-S rat models showed a biphasic distribution of apoptosis levels. This biphasic distribution was not observed in Buffalo rats as they were only studied at later time points (12-20 weeks). A significant effect on either testis weight or apoptosis in the CDT compared with the control descended testis (P > or = 0.1) has not been found in these three cryptorchid models, and the present results are discussed with reference to observations of other researchers in rodents and humans. While the cryptorchid testis showed a high level of labeled apoptotic cells per tubule in all rat strains, fertility was not affected and remained the same as controls at 12 and 24 weeks. There was, however, a marked strain difference in fertility in T-S as compared with Sprague Dawley rats. After 24 weeks of cryptorchidism, both control and cryptorchid T-S rats had a 44% pregnancy incidence compared with a 90% pregnancy incidence in Sprague Dawley rats. In addition, litter size in T-S control and cryptorchid rats were small compared with those of Sprague Dawley rats at 12 and 24 weeks.

The mode-coupling Liouville-Green approximation for a two-dimensional cochlear model.

The Liouville-Green [or Wentzel-Kramers-Brillouin (WKB)] approximation for the two-dimensional cochlear mechanics problem disagrees with the finite-difference solution in the region after the response peak. This disagreement has left doubts about the validity of the Liouville-Green approximation, and has never been satisfactorily explained. In this paper, it is shown that the Liouville-Green approximation fails to satisfy Laplace's equation. A new solution is proposed, called the mode-coupling Liouville-Green approximation, in which energy is coupled into a second wave mode, so as to obey Laplace's equation. The new approximation gives excellent quantitative agreement with the finite-difference solution. Furthermore, it may provide an explanation for a second vibration mode observed in biological cochleas. Also proposed is a high-order formulation of the stapes displacement term, which is necessary to obtain good agreement between the Liouville-Green approximation and finite-difference solutions at low frequencies.

In vitro fusion of human inguinal hernia with associated epithelial transformation.

The processus vaginalis (PV) is a peritoneal diverticulum which forms to allow descent of the fetal testis to the scrotum. During human development fusion and obliteration of the PV often fails to occur with the result that inguinal hernias are the most prevalent congenital abnormality requiring surgery in childhood. Androgen is proposed to regulate testicular descent via the genitofemoral nerve which releases the neuropeptide calcitonin gene-related peptide (CGRP). It is possible that subsequent fusion of the PV and tissue remodelling following descent is indirectly controlled by androgen via CGRP action. An organ culture assay was developed to assess fusion of the PV taken from inguinal herniotomy in infants. Fusion was induced in vitro by CGRP but not by CGRP 8-37, CGRP 27-37 or dihydrotestosterone in equimolar concentrations. Fusion was accompanied by transformation of the epithelium, as shown by staining of intermediate filament proteins, cytokeratin and vimentin. Localization studies for CGRP receptors on 25 specimens indicated CGRP acts on mesenchymal fibroblasts but not directly on PV epithelium suggesting an indirect pathway. Hepatocyte growth factor/scatter factor was found to induce fusion of PV and may be involved as an intermediate molecule in the fusion cascade. This study represents the first approach to understanding the humoral control and underlying mechanism by which the PV fuses.