Drivers and barriers of international migration of doctors to and from the United Kingdom: a scoping review.

BACKGROUND: Many high-income countries are heavily dependent on internationally trained doctors to staff their healthcare workforce. Over one-third of doctors practising in the UK received their primary medical qualification abroad. Simultaneously, an average of around 2.1% of doctors leave the UK medical workforce annually to go overseas. The aim of this study was to identify the drivers and barriers of international migration of doctors to and from the UK. METHODS: A scoping review was conducted. We searched EMBASE, MEDLINE, CINAHL, ERIC and BEI in January 2020 (updated October 2021). Grey literature and citation searching were also carried out. Empirical studies reporting on the drivers and barriers to the international migration of doctors to and from the UK published in the English language from 2009 to present were included. The drivers and barriers were coded in NVivo 12 building on an existing framework. RESULTS: 40 studies were included. 62% were quantitative, 18% were qualitative, 15% were mixed-methods and 5% were literature reviews. Migration into and out of the UK is determined by a variety of macro- (global and national factors), meso- (profession led factors) and micro-level (personal factors). Interestingly, many of the key drivers of migration to the UK were also factors driving migration from the UK, including: poor working conditions, employment opportunities, better training and development opportunities, better quality of life, desire for a life change and financial reasons. The barriers included stricter immigration policies, the registration process and short-term job contracts. CONCLUSIONS: Our research contributes to the literature by providing a comprehensive up-to-date review of the drivers and barriers of migration to and from the UK. The decision for a doctor to migrate is multi-layered and is a complex balance between push/pull at macro-/meso-/micro-levels. To sustain the UK's supply of overseas doctors, it is vital that migration policies take account of the drivers of migration particularly working conditions and active recruitment while addressing any potential barriers. Immigration policies to address the impact of Brexit and the COVID-19 pandemic on the migration of doctors to and from the UK will be particularly important in the immediate future. Trial registration PROSPERO CRD42020165748.

Exploring recent patterns of migration of doctors to the United Kingdom: a mixed-methods study.

INTRODUCTION: A shortage of doctors is currently one of the biggest challenges faced by the healthcare workforce in the United Kingdom (UK). While plans are in place to increase the number of medical school places, in the short-term this gap will need to continue to be filled by the international recruitment of doctors. The aim of this study is to identify key factors that explain the patterns of migration of doctors to the UK, in order to aid the development of policies to recruit and retain a sustainable workforce. METHODS: We analysed General Medical Council (GMC) secondary data on the patterns of migration of internationally trained doctors (2009-2019). Qualitative interviews were conducted with 17 stakeholders by videoconferencing which were audio-recorded, transcribed and thematically analysed using NVivo. RESULTS: In 2019, 34.5% of UK doctors were trained internationally mainly in India, Pakistan, Italy, Nigeria, Greece, Romania and Egypt. Most new registrations by internationally trained doctors from 2009-2019 did not have a specialty at the time of initial registration (96.2% in 2019). Only a relatively small number of these doctors go on to gain specialist or GP registration (11.6% within 5 years and 27.2% within 10 years of registration). The stakeholder interviews highlighted training opportunities and career progression as the main drivers of migration. The barriers internationally trained doctors face regarding specialty training included differences between UK and destination health systems, systematic bias, bureaucracy and selection processes not being accessible. CONCLUSION: This study makes a contribution to the literature by identifying recent patterns in the migration of doctors to the UK. The UK's dependence on internationally trained doctors has important global implications as source countries are losing skilled health workers which is undermining their health systems. In keeping with the WHO Global Code on the International Recruitment of Healthcare Personnel, policymakers need to consider how to reduce the UK's reliance on internationally trained doctors, particularly from countries on the safeguard list whilst continuing the drive to increase medical school places. Additional support is required for internationally trained doctors, to ensure that they get on the training programmes they seek, enabling their career progression.

Rehearsal's effect on recall and comprehension of orthodontic informed consent.

INTRODUCTION: Proper informed consent allows patients to take an active role in their own treatment decisions, and enhanced compliance might improve treatment outcomes. The objective of this research was to determine if handwritten rehearsal of core and custom consent items would increase short-term recall and comprehension. METHODS: A total of 90 patient-parent pairs were randomly assigned to 2 groups. After case presentation, each subject was provided 10 minutes to read a modified informed consent document. Group A received visual printouts containing the 4 core elements (root resorption, decalcification, pain, and relapse/retention) likely to be encountered by all patients and up to 4 custom elements (eg, impacted teeth, orthognathic surgery, or other case-specific treatment issues). Subjects identified and wrote what the image depicted and how it could affect treatment. Group B viewed a slideshow presentation on all 18 consent elements arranged from general to specific. All participants were interviewed, and each provided their sociodemographic data, as well as completed literacy, health literacy, and state anxiety questionnaires. The groups were compared for recall and comprehension through an analysis of covariance. RESULTS: The rehearsal intervention significantly improved recall and comprehension of the core elements (P = 0.001). Rehearsal also improved custom recall and comprehension, but not significantly. Group B performed significantly better on treatment questions (P = 0.001). Overall, as anxiety increased, correct responses decreased. CONCLUSIONS: The rehearsal group improved recall and comprehension of the core and custom elements of informed consent and proved a more efficient method than an audiovisual presentation to provide informed consent. It also improved meeting legal obligations.

Serous cystadenocarcinoma of the pancreas: report of a case and management reflections.

BACKGROUND: Serous adenomas represent 1-2% of pancreatic neoplasms and typically are asymptomatic not requiring any treatment and simple observation is the option of choice. Although, they carry a realistic risk of malignancy despite the general view that they never become malignant. We report a case, which, according to our best knowledge is the 27th case reported in the literature. METHODS: We reviewed the literature by performing a search in Pub Med and Medline. RESULTS: A 86-year old patient known to have a serous cystadenoma of the pancreas treated conservatively through a close clinical and radiological follow up which was unattended for 4 years ending up to our emergency department suffering an acute abdomen. Exploratory laparotomy revealed a perforated prepyloric ulcer which was treated accordingly. Patient died some weeks later due to severe medical co morbidities. CONCLUSION: Serous cystic neoplasms of the pancreas carry a realistic risk of malignancy despite the general view that they never become malignant. In our opinion the treatment strategy of serous cystic neoplasms of the pancreas should be aggressive even in cases of remote metastases since prognosis of the disease is satisfactory.

The three-surgeon technique for liver tissue dissection: towards real bloodless hepatectomy.

PURPOSE: Bleeding during hepatectomy remains a major cause of mortality despite recent developments in surgical and anaesthetic techniques. To date there is no single surgical device that combines speed, efficient haemostasis and safety for the adjacent vital structures during parenchymal division. This article presents the Three Surgeon Technique (3ST), a novel method of parenchymal dissection for major hepatectomies and compare it with our standard radiofrequency ablation (RFA) - assisted technique. METHODS: 77 patients who underwent major liver resection were divided into two groups: 38 of them (group A) underwent 41 RFA-assisted liver resections and 39 (group B) underwent 41 hepatectomies with the 3ST. The data for the 3ST were prospectively collected and compared to the already collated RFA patient group. RESULTS: Blood transfusion was necessary in 28 and 13 patients in group A and B respectively (p=0.016), with an average of 1.7 and 0.6 units of red blood cells (p<0.001). The Pringle maneuver was not required with the 3ST. The mean time of parenchymal dissection was 90.49 and 77.52 min in group A and B, respectively (p=0.007). CONCLUSION: The 3ST is a novel, reliable and safe alternative to the stand alone RFA-assisted technique. It is a faster procedure, and requires less blood units transfusion.

The significance of DNA image cytometry and Edmondson-Steiner grading on prognosis after curative resection of hepatocellular carcinoma.

PURPOSE: Hepatocellular carcinoma (HCC) is the commonest primary cancer of the liver. Hepatic resection remains the main curative option, although the incidence of disease recurrence in the remaining hepatic parenchyma is high and accounts for the leading cause of death post resection. For this reason, the need to identify prognostic factors which may determine treatment response and survival is of paramount importance. In this study we assessed whether DNA image cytometry and Edmondson-Steiner grading could be used as prognostic factors in a cohort of patients with HCC undergoing radical hepatic resection. METHODS: Forty-four patients with HCC who underwent radical resection were retrospectively analyzed. Histological grading according to Edmondson and Steiner and DNA ploidy using DNA image cytometry, were the two parameters analyzed. Pearson's x(2) or Fisher's exact tests were used to test for any associations between categorical variables. Univariate semi-parametric Cox proportional hazard regression models were used to assess the effect of explanatory variables on death. All reported p values were based on two-sided tests and compared to a significance level of 0.05. RESULTS: In univariate Cox regression analysis, adverse survival outcome was strongly associated with high DNA score and advanced histological grading. Patients with ploidy score >2.2 had 3.95 times higher probability of death, as compared to those with ploidy score ≤ 2.2. Edmondson-Steiner grades III and IV were also associated with 20.49 and 34.47 higher probability of death respectively as compared to grade I. CONCLUSION: Our results validate the prognostic significance of DNA image cytometry and Edmondson-Steiner grading following curative resection of HCC.

Characteristics of patients presenting with erythema nodosum and sarcoidosis.

We explored the relationship between erythema nodosum (EN) and sex, age, serum angiotensin converting enzyme (ACE), bronchoalveolar lavage lymphocytosis (BAL-I), interstitial granulomas and radiological stage in patients presenting with pulmonary sarcoidosis in Ireland. Sixty-nine patients diagnosed with sarcoidosis between 2003 and 2006 were studied. Forty one patients (59%) were male. Sixteen patients (23%) presented with EN. Forty one patients of 65 (63%) had transbronchial biopsies demonstrating non-caseating granulomas. Patients with sarcoidosis presenting with EN were more likely to be female (p=0.042), younger (p=0.012) and have earlier stage pulmonary disease (p=0.02). There were no correlations between serum ACE, interstitial granulomas and disease stage. BAL-I did however predict increasing disease radiological stage (p=0.042). In this study, one quarter of patients with sarcoidosis presented with EN among their presenting features. These patients were more likely to be young females with early stage radiological disease.

Stability of the biodiversity of the surface consortia of Gubbeen, a red-smear cheese.

A total of 1,052 bacteria and 828 yeasts were isolated from the surface flora of 6 batches of Gubbeen cheese made in 1996-1997 and 2002-2003. Stability of the microflora was evaluated over time and also during ripening at 4, 10, and 16 d (batches 4, 5, and 6) or at 4, 16, 23, and 37 d (batches 1, 2, and 3). Bacteria were identified using pulsed-field gel electrophoresis, repetitive extragenic palindromic-PCR, and 16S rRNA gene sequencing, and yeasts were identified by Fourier transform infrared spectroscopy. The bacteria included at least 17 species, of which the most common were Staphylococcus saprophyticus (316 isolates), Corynebacterium casei (248 isolates), Brevibacterium aurantiacum (187 isolates), Corynebacterium variabile (146 isolates), Microbacterium gubbeenense (55 isolates), Staphylococcus equorum/cohnii (31 isolates), and Psychrobacter spp. (26 isolates). The most common yeasts were Debaryomyces hansenii (624 isolates), Candida catenulata (135 isolates), and Candida lusitaniae (62 isolates). In all batches of cheese except batch 2, a progression of bacteria was observed, with staphylococci dominating the early stages of ripening and coryneforms the later stages. No progression of yeast was found. Pulsed-field gel electrophoresis showed that several different strains of the 5 important species of bacteria were present, but generally only one predominated. The commercial strains used for smearing the cheese were recovered, but only in very small numbers early in ripening. Four species, B. aurantiacum, C. casei, C. variabile, and Staph. saprophyticus, were found on all batches of cheese, but their relative importance varied considerably. The results imply that significant variation occurs in the surface microflora of cheese.

Rapidly changing pulmonary infiltrates.

Pulmonary eosinophilia responds very quickly to steroid treatment. Chronic pulmonary eosinophilia is common in middle aged females. We report on a patient who presented with subacute onset of shortness of breath, severe weight loss associated with a rise in the peripheral eosinophil count. She was treated successfully with steroids resulting in complete resolution of the pulmonary infiltrates.

Identification of the Corticobulbar Tracts of the Tongue and Face Using Deterministic and Probabilistic DTI Fiber Tracking in Patients with Brain Tumor.

BACKGROUND AND PURPOSE: The corticobulbar tract of the face and tongue, a critical white matter tract connecting the primary motor cortex and the pons, is rarely detected by deterministic DTI fiber tractography. Detection becomes even more difficult in the presence of a tumor. The purpose of this study was to compare identification of the corticobulbar tract by using deterministic and probabilistic tractography in patients with brain tumor. MATERIALS AND METHODS: Fifty patients with brain tumor who underwent DTI were studied. Deterministic tractography was performed by using the fiber assignment by continuous tractography algorithm. Probabilistic tractography was performed by using a Monte Carlo simulation method. ROIs were drawn of the face and tongue motor homunculi and the pons in both hemispheres. RESULTS: In all subjects, fiber assignment by continuous tractography was ineffectual in visualizing the entire course of the corticobulbar tract between the face and tongue motor cortices and the pons on either side. However, probabilistic tractography successfully visualized the corticobulbar tract from the face and tongue motor cortices in all patients on both sides. No significant difference (P < .08) was found between both sides in terms of the number of voxels or degree of connectivity. The fractional anisotropy of both the face and tongue was significantly lower on the tumor side (P < .03). When stratified by tumor type, primary-versus-metastatic tumors, no differences were observed between tracts in terms of the fractional anisotropy and connectivity values (P > .5). CONCLUSIONS: Probabilistic tractography successfully reconstructs the face- and tongue-associated corticobulbar tracts from the lateral primary motor cortex to the pons in both hemispheres.

Acute corneal hydrops in keratoconus: a national prospective study of incidence and management.

PurposeTo determine incidence and management of acute corneal hydrops in the UK.MethodsWe used the BOSU report card system to survey cases of acute corneal hydrops in patients with keratoconus that occurred in the UK between November 2009 and December 2010. Ophthalmologists who reported a case were sent an initial questionnaire, with a follow-up questionnaire after 6 months. We collected information on the demographics, complications, changes in visual acuity, and management. The 2011 National Census was used as a source for population and ethnicity in the UK.ResultsThere were 73 incident cases of acute corneal hydrops, with a response to the initial questionnaire for 64 (88%) patients and follow-up data at 6 months for 57 (78%) patients. For the 64 confirmed cases the median (interquartile range) age of onset was 31.9 (23.2, 41.3) years and 48 (75%) of the cases occurred in males. A total of 42 (66%) patients were white, 14 (22%) were South Asian, and 7 (11%) were black. The proportion of South Asian and black patients with acute corneal hydrops was significantly higher than in the general population (P<0.001). The minimum estimated annual incidence of acute corneal hydrops in patients with keratoconus was estimated to be 1.43 (1.10, 1.83) per 1000. At 6 months following acute corneal hydrops a decision to proceed with keratoplasty had been made for 12 (20.3%) patients.ConclusionsThis is the first population-based estimate of the incidence of acute corneal hydrops in keratoconus.

Challenges in Identifying the Foot Motor Region in Patients with Brain Tumor on Routine MRI: Advantages of fMRI.

BACKGROUND AND PURPOSE: Accurate localization of the foot/leg motor homunculus is essential because iatrogenic damage can render a patient wheelchair- or bed-bound. We hypothesized the following: 1) Readers would identify the foot motor homunculus <100% of the time on routine MR imaging, 2) neuroradiologists would perform better than nonradiologists, and 3) those with fMRI experience would perform better than those without it. MATERIALS AND METHODS: Thirty-five attending-level raters (24 neuroradiologists, 11 nonradiologists) evaluated 14 brain tumors involving the frontoparietal convexity. Raters were asked to identify the location of the foot motor homunculus and determine whether the tumor involved the foot motor area and/or motor cortex by using anatomic MR imaging. Results were compared on the basis of prior fMRI experience and medical specialty by using Mann-Whitney U test statistics. RESULTS: No rater was 100% correct. Raters correctly identified whether the tumor was in the foot motor cortex 77% of the time. Raters with fMRI experience were significantly better than raters without experience at foot motor fMRI centroid predictions (13 ± 6 mm versus 20 ± 13 mm from the foot motor cortex center, P = 2 × 10(-6)) and arrow placement in the motor gyrus (67% versus 47%, P = 7 × 10(-5)). Neuroradiologists were significantly better than nonradiologists at foot motor fMRI centroid predictions (15 ± 8 mm versus 20 ± 14 mm, P = .005) and arrow placement in the motor gyrus (61% versus 46%, P = .008). CONCLUSIONS: The inability of experienced readers to consistently identify the location of the foot motor homunculus on routine MR imaging argues for using fMRI in the preoperative setting. Experience with fMRI leads to improved accuracy in identifying anatomic structures, even on routine MR imaging.

Lipopolysaccharide in adherence of Pseudomonas aeruginosa to the cornea and contact lenses.

PURPOSE: To determine the role of smooth or rough lipopolysaccharide on adherence of Pseudomonas aeruginosa bacteria to the rat cornea in vitro and on contact lenses of differing types. METHODS: Adherence of a smooth (AK957) and isogenic rough strain (AK1012) of P. aeruginosa bacteria to rat corneas that were either normal, traumatized using a 20-gauge needle or treated for 15 min with 0.1N sodium hydrochloric acid was assessed by homogenization and viable counting. Adherence of these organisms to 43 unworn contact lenses representing the four Food and Drug Administration lens groups was also assessed using viable counts. RESULTS: Attachment to contact lenses was greater for the smooth strain for all four lens types (P < 0.001). No variation in adherence to the different lens types was observed. Smooth bacteria also adhered to the cornea to a greater extent than the rough strain, regardless of trauma type (P < 0.001). Adherence to traumatized corneas was greater than to nontraumatized corneas for both strains of P. aeruginosa bacteria (P < 0.01). Measurement of surface hydrophobicity of the two bacterial strains revealed that the smooth strain was more hydrophobic than the rough strain (P < 0.001), perhaps accounting for the adherence pattern. CONCLUSIONS: These results indicate that bacterial surface characteristics may be important determinants of adherence and could explain the propensity of certain bacterial strains to infect the cornea.

Oxygen permeability of collagen shields.

The oxygen permeability (Dk) of ten 24-hr collagen shields was measured directly by polarographic methodology at approximately 2 hr of hydration. Edge and boundary effects were included in the calculations. Dk was found to be approximately 26 x 10(-11) cm ml O2/sec ml mmHg at 35 degrees C. Mean water content of the shields was 65.7% (SD = 1.0%) as measured by a hand refractometer. Therefore, the projected oxygen transmissibility of collagen shields is expected to be compatible with normal corneal metabolism.

Differing outcomes of gram-positive and gram-negative peritonitis.

Peritonitis remains the leading cause of patient dropout from continuous peritoneal dialysis (CPD) therapy. Few studies have compared patient morbidity, mortality, and outcome for patients undergoing CPD who develop gram-positive and gram-negative peritonitis. We retrospectively reviewed the charts of patients who developed either gram-positive or gram-negative peritonitis between January 1, 1993, and December 31, 1995. Three hundred seventy-five patients who developed 415 episodes of gram-positive and gram-negative peritonitis were maintained on CPD therapy during this time period. There was no difference in age, race, and sex between patients who developed gram-positive or gram-negative peritonitis. More patients with diabetes developed gram-negative peritonitis than gram-positive peritonitis (53% v 40%, respectively; P < 0.05). Coagulase-negative staphylococcal species accounted for 47% of all gram-positive episodes, whereas Klebsiella organisms, Escherichia coli, and Enterobacter organisms accounted for 63% of all gram-negative episodes. Significantly more patients who developed gram-positive peritonitis continued CPD therapy 2 weeks and 6 months after the onset of peritonitis than patients who developed gram-negative peritonitis (97% v 73%; P < 0.05 at 2 weeks and 81% v 58% at 6 months; P < 0.05, respectively). Nine percent of the patients who developed gram-positive peritonitis died within 6 months after the onset of peritonitis, whereas 21% of the patients who developed gram-negative peritonitis died (P < 0.05). Patients who developed gram-negative peritonitis were significantly more likely to require hospitalization than patients who developed gram-positive peritonitis (74% v 24%; P < 0.001). More patients with gram-negative peritonitis required peritoneal catheter removal than patients with gram-positive peritonitis (18% v 4%; P < 0.001). Thirty-two percent of the patients who developed gram-positive peritonitis re-developed an episode of peritonitis with the same organism compared with only 9% of the patients who developed gram-negative peritonitis. Furthermore, peritonitis recurrence with the same organism within 6 months after the initial episode was noted in 60% of the patients with peritonitis caused by Staphylococcus aureus compared with 24% of patients with peritonitis caused by other gram-positive organisms (P < 0.05). We conclude that the outcomes of gram-positive and gram-negative peritonitis are different. When rates of peritonitis are used to predict outcome, it appears that gram-positive and gram-negative peritonitis rates need to be examined separately.

Three cases of paradoxical vocal cord adduction followed up over a 10-year period.

Paradoxical vocal cord adduction (PVCA) is a rare disorder that may present with symptoms similar to asthma. Incorrect diagnosis may result in patients being unwittingly treated with prolonged high doses of antiasthma medication. PVCA probably forms part of a spectrum of uncommon and complex breathing disorders related to laryngeal dysfunction. Herein, we describe three cases of PVCA that illustrate the spectrum of clinical and physiologic presentation and the long-term natural history over a 10-year follow-up period. We conclude that PVCA, contrary to previous reports, is not always a benign condition; it may feature marked hypoxemia, fail to respond to previously advocated therapeutic strategies, and can persist on a long-term basis.

Corneal pathophysiology with contact lens wear.

Contact lens wear induces a wide spectrum of changes in the appearance and function of the cornea. The most salient effect of lens wear is the hypoxically induced reduction in the rate of metabolic activity of the corneal epithelium and its sequellae. Other important alterations to corneal health associated with contact lens wear may be caused by antigenic and toxic stimuli, mechanical forces, osmotic effects and carbon dioxide retention. Perhaps the most important task facing the contact lens clinician is to distinguish between an acceptable state of physiological modification and an anomalous or pathological state of hypofunction. In this article, we review the assortment of corneal changes primarily on the basis of the causative agents and time scale with reference to the physical and chemical processes leading to the observed signs or symptoms. This procedure allows a strong foundation for understanding the etiology and management principles for the variety of effects that contact lenses may have on the cornea.

The duration of normal visual exposure necessary to prevent form deprivation myopia in chicks.

The aim of this study was to determine the minimum daily period of exposure to normal visual stimulation required to prevent occlusion induced myopia in chicks. Chicks were treated with monocular translucent occlusion in a 12 hr light/12 hr dark cycle. Occluders were removed for 0 (constant occlusion), 15, 20, 30, 40, 60, 75, 90, 120, 150, 240 or 720 (no occlusion) minutes each day for either 2 or 3 weeks. Fellow eyes and the eyes of normal chicks (bilaterally unoccluded) were used as controls. Occlusion-induced myopia and axial elongation were found to decrease significantly (P < 0.01) with increasing daily exposure to normal visual stimulation. Application of a time series equation to the data estimates that 30 and 130 min of normal visual exposure per day reduces myopia by 50 and 95% respectively. This study demonstrated that the regulation of ocular growth is affected strongly by short periods of normal visual stimulation in the presence of long periods of abnormal stimulation.

The effect of an interrupted daily period of normal visual stimulation on form deprivation myopia in chicks.

The aim of this study was to determine whether an integrator of neural activity influences the amount of myopia and axial elongation resulting from deprivation of form vision. The effects on ocular parameters of a continuous period of 30 min per day of normal vision was compared to two exposures of 15 min duration each, or three exposures of 10 min each. For the remaining time, chicks had monocular translucent occlusion in a 12 hr light/12 hr dark diurnal cycle, for either 2 or 3 weeks. Fellow eyes and the eyes of bilaterally unoccluded chicks were used as controls. We found that several short periods of normal visual stimulation per day were more effective in preventing the development of form deprivation myopia and axial elongation than was one single period of the same total duration, after both 2 and 3 weeks of treatment. This study suggests that the level of neural activity in the retina may have a cumulative effect in influencing ocular growth.

Short term treatment with St. John's wort, hypericin or hyperforin fails to induce CYP450 isoforms in the Swiss Webster mouse.

This investigation was designed to determine whether St. John's wort (SJW)(435 mg/kg/d), a readily available antidepressant, or its purported active constituents hypericin (1 mg/kg/d) and hyperforin (10 mg/kg/d) were able to induce various hepatic cytochrome P450 (CYP450) isoforms. SJW, hypericin and hyperforin were administered to male Swiss Webster mice for four consecutive days and hepatic microsomes were prepared on day 5. None of the three treatments resulted in a statistical change in total hepatic CYP450 (SJW treated 0.95 +/- 0.09 nmol/mg vs control 1.09 +/- 0.14 nmol/mg). Furthermore, the catalytic activities of CYP1A2. CYP2E1 and CYP3A were unchanged from control following all three treatments as determined by ethoxyresorufin O-deethylation, p-nitrophenol hydroxylation and erythromycin N-demethylation respectively. Additionally, western immunoblotting demonstrated that there was no significant change in the polypeptide levels of any of the three isoforms. These results indicate that four days of treatment with moderate to high doses of SJW, hyperforin or hypericin fails to induce these CYP450 isoforms in the male Swiss Webster mouse.