Sex-dependent Effect of In-utero Exposure to Δ9-Tetrahydrocannabinol on Glucagon and Stathmin-2 in Adult Rat Offspring

OBJECTIVES

Administration of Δ⁹-tetrahydrocannabinol (Δ⁹-THC) to pregnant rats results in glucose intolerance, insulin resistance and reduced islet mass in female, but not male, offspring. The effects of Δ⁹-THC on other islet hormones is not known. One downstream target of the cannabinoid receptor, stathmin-2 (Stmn2), has recently been shown to suppress glucagon secretion, thereby suggesting Δ⁹-THC may also affect alpha-cell function. The aim of the present study was to determine the effects of in-utero Δ⁹-THC exposure on the profile of glucagon, insulin and Stmn2 in the rat offspring islet and serum.

METHODS

Pregnant Wistar rat dams were injected with Δ⁹-THC (3 mg/kg per day, intraperitoneally) or vehicle from gestational day 6 to birth. Offspring were euthanized at postnatal day 21 (PND21) or at 5 months (adult) to collect blood and pancreata.

RESULTS

At PND21, control and Δ⁹-THC-exposed offspring showed that Stmn2 had a strong colocalization with glucagon (Pearson's correlation coefficient ≥0.6), and a weak colocalization with insulin (Pearson's correlation coefficient <0.4) in both males and females, with no changes by either treatment or sex. In adult female offspring in the Δ⁹-THC group, intensity analysis indicated an increased insulin-to-glucagon (I/G; p<0.05) ratio and a decreased glucagon-to-Stmn2 (G/S; p<0.01) ratio, and no changes in these ratios in adult males. Furthermore, Δ⁹-THC did not alter fasting blood glucose and serum insulin levels in either male or female adult offspring. However, female Δ⁹-THC-exposed offspring exhibited an increased I/G ratio (p<0.05) and decreased G/S ratio in serum by adulthood (p<0.05).

CONCLUSION

Collectively, the reduced G/S ratio in both islet and serum in association with an increased serum I/G ratio has direct correlations with early glucose intolerance and insulin resistance observed exclusively in females' offspring in this prenatal cannabinoid model.

Maternal exposure to Δ9-tetrahydrocannabinol impairs female offspring glucose homeostasis and endocrine pancreatic development in the rat

Recent reports indicate that 7% of pregnant mothers in North America use cannabis. This is concerning given that in utero exposure to Δ9-tetrahydrocannabinol (Δ9-THC), the main psychoactive component in cannabis, causes fetal growth restriction and may alter replication and survival of pancreatic β-cells in the offspring. Accordingly, we hypothesized that maternal exposure to Δ9-THC during pregnancy would impair postnatal glucometabolic health of offspring. To test this hypothesis, pregnant Wistar rats were treated with daily intraperitoneal injections of either 3 mg/kg Δ9-THC or vehicle from gestational day 6 to birth. Offspring were subsequently challenged with glucose and insulin at 5 months of age to assess glucose tolerance and peripheral muscle insulin sensitivity. Female offspring exposed to Δ9-THC in utero were glucose intolerant, associated with blunted insulin response in muscle and increased serum insulin concentration 15 min after glucose challenge. Additionally, pancreata from male and female offspring were harvested at postnatal day 21 and 5 months of age for assessment of endocrine pancreas morphometry by immunostaining. This analysis revealed that gestational exposure to Δ9-THC reduced the density of islets in female, but not male, offspring at postnatal day 21 and 5 months, culminating in reduced β-cell mass at 5 months. These results demonstrate that fetal exposure to Δ9-THC causes female-specific impairments in glucose homeostasis, raising concern regarding the metabolic health of offspring, particularly females, exposed to cannabis in utero.

Radiomics in Brain Tumor: Image Assessment, Quantitative Feature Descriptors, and Machine-Learning Approaches

Radiomics describes a broad set of computational methods that extract quantitative features from radiographic images. The resulting features can be used to inform imaging diagnosis, prognosis, and therapy response in oncology. However, major challenges remain for methodologic developments to optimize feature extraction and provide rapid information flow in clinical settings. Equally important, to be clinically useful, predictive radiomic properties must be clearly linked to meaningful biologic characteristics and qualitative imaging properties familiar to radiologists. Here we use a cross-disciplinary approach to highlight studies in radiomics. We review brain tumor radiologic studies (eg, imaging interpretation) through computational models (eg, computer vision and machine learning) that provide novel clinical insights. We outline current quantitative image feature extraction and prediction strategies with different levels of available clinical classes for supporting clinical decision-making. We further discuss machine-learning challenges and data opportunities to advance radiomic studies.

Combined PET/MRI: Global Warming-Summary Report of the 6th International Workshop on PET/MRI, March 27-29, 2017, Tübingen, Germany

The 6th annual meeting to address key issues in positron emission tomography (PET)/magnetic resonance imaging (MRI) was held again in Tübingen, Germany, from March 27 to 29, 2017. Over three days of invited plenary lectures, round table discussions and dialogue board deliberations, participants critically assessed the current state of PET/MRI, both clinically and as a research tool, and attempted to chart future directions. The meeting addressed the use of PET/MRI and workflows in oncology, neurosciences, infection, inflammation and chronic pain syndromes, as well as deeper discussions about how best to characterise the tumour microenvironment, optimise the complementary information available from PET and MRI, and how advanced data mining and bioinformatics, as well as information from liquid biomarkers (circulating tumour cells and nucleic acids) and pathology, can be integrated to give a more complete characterisation of disease phenotype. Some issues that have dominated previous meetings, such as the accuracy of MR-based attenuation correction (AC) of the PET scan, were finally put to rest as having been adequately addressed for the majority of clinical situations. Likewise, the ability to standardise PET systems for use in multicentre trials was confirmed, thus removing a perceived barrier to larger clinical imaging trials. The meeting openly questioned whether PET/MRI should, in all cases, be used as a whole-body imaging modality or whether in many circumstances it would best be employed to give an in-depth study of previously identified disease in a single organ or region. The meeting concluded that there is still much work to be done in the integration of data from different fields and in developing a common language for all stakeholders involved. In addition, the participants advocated joint training and education for individuals who engage in routine PET/MRI. It was agreed that PET/MRI can enhance our understanding of normal and disrupted biology, and we are in a position to describe the in vivo nature of disease processes, metabolism, evolution of cancer and the monitoring of response to pharmacological interventions and therapies. As such, PET/MRI is a key to advancing medicine and patient care.

Combined PET/MRI: from Status Quo to Status Go. Summary Report of the Fifth International Workshop on PET/MR Imaging; February 15-19, 2016; Tübingen, Germany

This article provides a collaborative perspective of the discussions and conclusions from the fifth international workshop of combined positron emission tomorgraphy (PET)/magnetic resonance imaging (MRI) that was held in Tübingen, Germany, from February 15 to 19, 2016. Specifically, we summarise the second part of the workshop made up of invited presentations from active researchers in the field of PET/MRI and associated fields augmented by round table discussions and dialogue boards with specific topics. This year, this included practical advice as to possible approaches to moving PET/MRI into clinical routine, the use of PET/MRI in brain receptor imaging, in assessing cardiovascular diseases, cancer, infection, and inflammatory diseases. To address perceived challenges still remaining to innovatively integrate PET and MRI system technologies, a dedicated round table session brought together key representatives from industry and academia who were engaged with either the conceptualisation or early adoption of hybrid PET/MRI systems. Discussions during the workshop highlighted that emerging unique applications of PET/MRI such as the ability to provide multi-parametric quantitative and visual information which will enable not only overall disease detection but also disease characterisation would eventually be regarded as compelling arguments for the adoption of PET/MR. However, as indicated by previous workshops, evidence in favour of this observation is only growing slowly, mainly due to the ongoing inability to pool data cohorts from independent trials as well as different systems and sites. The participants emphasised that moving from status quo to status go entails the need to adopt standardised imaging procedures and the readiness to act together prospectively across multiple PET/MRI sites and vendors.

Patient recollections of perioperative anaesthesia risks

There is widespread variation as to the method of presentation of informed anaesthetic consent with little empirical data on the nature of communication and how much information is retained. At a dedicated anaesthesia pre-admission clinic, 149 patients undergoing elective surgery under general anaesthesia were both verbally informed and shown written information about four major and three minor anaesthesia risks. The major risks were death, pneumonia, heart attack and stroke. The minor risks were dental damage, nausea and vomiting. On the day of scheduled surgery, retention of information about these anaesthetic risks was examined. Thirty-eight patients (26%) could not recall any anaesthesia risks, 55 patients (37%) could not recall any major risks and 126 patients (84%) could not recall any minor risks. Our findings indicate that patients should receive a second explanation on the day of surgery, even if informed consent was provided only two weeks earlier.

Convenient and Efficient Synthesis of a Lanthanide-Coordinated, Diethylene Triamine Pentaacetic Acid Labeled Biopolymer as an Assay for the Cholecystokinin B Receptor

To develop an assay for the cholecystokinin B receptor with an Eu(3+)-labeled cholecystokinin peptide via a diethylene triamine pentaacetic acid chelating linker, a commercial dianhydride diethylene triamine pentaacetic acid precursor was directly attached to the N-terminus of cholecystokinin peptides by a solid-phase synthesis method with a satisfactory yield and purity after reverse-phase high-performance liquid chromatography separation. Lanthanide was then coordinated to the peptide via a diethylene triamine pentaacetic acid bifunctional agent. This method is a useful approach to the large-scale synthesis of lanthanide(3+)-coordinated, diethylene triamine pentaacetic acid labeled biopolymers. This research provides not only a simple and convenient method for the preparation of lanthanide-based peptide ligand libraries but also possible lanthanide-based high-throughput screening of peptide receptors with a timeresolved fluorescence assay system. Five biopolymers were synthesized and characterized with high-resolution electrospray ionization in this study.

Exploring the views of second-year Foundation Programme doctors and their educational supervisors during a deanery-wide pilot Foundation Programme

AIM

To explore the views of second-year Foundation Programme doctors (F2s) and their educational supervisors taking part in a deanery-wide pilot Foundation Programme, in order to gain an understanding of their perceptions of the available learning experiences, support and supervision.

METHODS

20 semi-structured interviews were undertaken with randomly selected F2 doctors and educational supervisors participating in the deanery-wide pilot Foundation Programme.

RESULTS

F2 trainees received appropriate and sufficient support and supervision from a variety of sources during their placements; however, it was believed that additional training of educational supervisors was required. Trainees reported some problems with the perception of the role of an F2; further understanding of the purpose and role of the F2 programme is required at trust level. The portfolio was viewed positively as a record and a learning tool, but was thought to be too bureaucratic. Trainees believed that it was more beneficial to their careers to take part in a foundation programme as opposed to a traditional senior house officer post, but both trainees and educational supervisors expressed some concerns about the generic nature of some skills F2s were expected to acquire.

CONCLUSIONS

This evaluation has highlighted successful aspects of the Foundation Programme, particularly with regard to the level of support and range of experiences provided for trainees. Issues of concern to both trainees and educational supervisors have been identified, which require additional understanding.

The portfolio: how was it for you? Views of F2 doctors from the Mersey Deanery Foundation Pilot

A study was conducted between August 2004 and August 2005 to explore the experiences of Foundation year 2 (F2) trainees who used the learning portfolio on the Mersey Deanery pilot scheme. Seventy-three trainees (77%) reported receiving their portfolio during their induction. In their first four-month placement, 90 trainees (96%) completed the two case-based discussions, 80 (87%) the three mini clinical examinations and 92 (97%) the two direct observation of practical procedures. The number of trainees who felt there was an opportunity to make a record of and analyse clinical critical incidents and critical incidents related to professional behaviour was only 32 (35%) and 13 (15%) respectively. Free text responses suggested that trainees appreciate the portfolio but that an understanding of its content and purpose, particularly by educational supervisors, is paramount to its success.

Non-invasive in vivo determination of UVA efficacy of sunscreens using diffuse reflectance spectroscopy

BACKGROUND

Evaluation of sunscreen efficacy is most relevant when measured on the surface it is meant to protect, namely on human skin in vivo. Application of any material to the surface of the skin alters its optical properties. Diffuse reflectance spectroscopy (DRS) is a non-invasive technique to measure changes in the optical properties of the skin decoupled from its biological responses following sunscreen application.

METHODS

This study compared measurements of UVA efficacy of oxybenzone and avobenzone at different concentrations (0-5%) using DRS, human phototest and an in vitro technique. Twenty subjects were enrolled for each product measured by DRS and 10 different subjects were enrolled for each product measured by human phototest. Six areas 5 cm x 10 cm were outlined on each subject's back. DRS measurements were performed on four subsites within each area before and 20 min after sunscreen application. UVA efficacy for each concentration of product was calculated from the measured transmission spectrum of a given product convoluted with the spectrum of a Xenon light source adequately filtered to obtain the UVA spectrum from 320 to 400 nm and the erythema action spectrum. Phototesting was performed using the same light source and persistent pigment darkening as the biological endpoint. Measurements were made with sunscreen coverage of 2 mg/cm2. In vitro measurements were performed using an Optometrics instrument.

RESULTS

All three techniques showed a linear response between calculated UVA efficacy and product concentration.

CONCLUSIONS

This study showed that DRS is a rapid and reproducible method to calculate UVA efficacy of sunscreen materials and that its results correlate closely with those obtained by human phototesting.

Interrater reliability of the Glasgow Coma Scale scoring among nurses in sub-specialties of critical care

The Glasgow Coma Scale (GCS) is used as an assessment tool to measure the levels of consciousness and coma in patients. This research investigated the reliability of scoring the GCS among registered nurses (RNs) working in five different sub-specialty clinical areas of critical care; general intensive care, neurosurgical intensive care, coronary care, emergency room and post anaesthetic recovery room. Seven video recordings were made of six patients (one patient was recorded twice) having their level of neurological response assessed utilising the GCS. Seventy five RNs (15 from each sub-specialty) viewed each of the GCS assessments on the videotape and rated each patient on the scoring sheet provided. Analysis was performed for all RN subjects as a single group as well as separately for each of the five groups under investigation. The ratings for the first six videos were used to test interrater reliability and the scores from videotape four and seven (same patient) were used to calculate intrarater reliability. Based on comparison with expert scores, of the 75 participants, 38 responded correctly to eye opening responses; only 26 responded correctly to the motor response ratings. However, a better accuracy was achieved in the verbal response category with 67 participants responding correctly. Education qualifications and previous neurosurgical experience were statistically significant with regard to the nurses' accuracy of GCS assessment with p values of 0.004 and 0.043 respectively. The results were consistent with previously published studies demonstrating the motor response rating is most problematic in relation to rate accuracy.

Aging and effects of ultraviolet A exposure may be quantified by fluorescence excitation spectroscopy in vivo

The fluorescence properties of skin chromophores such as tryptophan and collagen cross-links might be useful markers of aging and photoaging. As the fluorescence of pepsin-digestible collagen cross-links was found to increase with aging and decrease with photoaging we investigated the characteristics of this dependence. In vivo fluorescence excitation spectra (emission at 380 nm) of SKH hairless mouse model skin are characterized by two bands centered near 295 nm and 335 nm due, respectively, to epidermal tryptophan moieties and pepsin-digestible collagen cross-links. Several groups of hairless mice were followed over a period of 18 mo to document changes in skin fluorescence with aging. Other groups of animals were exposed to either broad band or narrowband ultraviolet A radiation to determine the effects of ultraviolet A exposure on the fluorescence of the dermal collagen cross-links and to determine an action spectrum for the induced changes. We also found that the intensity of pepsin-digestible collagen cross-links in vivo increases linearly with age and that the fluorescence of epidermal tryptophan decreases linearly with age. We found that the fluorescence of pepsin-digestible collagen cross-links decreases immediately following exposure to ultraviolet A whereas epidermal tryptophan fluorescence increases. Both changes were dose dependent but the increase in tryptophan fluorescence occurred exclusively in young animals (2--6 mo old). We found that the ultraviolet-induced fluorescence decrease of pepsin-digestible collagen cross-links is wavelength specific. The action spectrum for the ultraviolet A effect on the in vivo fluorescence of pepsin-digestible collagen cross-links shows a distinct maximum at 335 nm that corresponds to the maximum in the fluorescence excitation spectrum due to pepsin-digestible collagen cross-links. Our results seem to indicate that in vivo fluorescence of epidermal tryptophan moieties and collagen cross-links in the dermal matrix may serve as markers for skin aging, for photoaging, and for immediate assessment of exposure to ultraviolet A radiation.

A rapid method to detect dried saliva stains swabbed from human skin using fluorescence spectroscopy

Saliva on skin is important in forensic trace evidence. If areas where saliva is present can be outlined, this may lead to DNA analysis and identification. This study describes a rapid and non-destructive method to detect dried saliva on the surface of the skin by fluorescence spectroscopy. Eighty-two volunteers deposited samples of their own saliva on the skin of their ventral forearm. A control sample of water was deposited at three different sites on the contralateral arm. Saliva and water control were then allowed to air-dry. Swab samples were taken from dried saliva and control sites and were dissolved in 0.1M KCl solution. Emission spectra were obtained from the solution and were characterized by a principal maximum at 345-355nm with excitation at 282nm. The fluorescence emission intensity was greater than background readings obtained from the control swab site in 80 of 82 volunteers (approximately 97.6%). The fluorescence profile of saliva samples were similar to those obtained from aqueous samples of pure amylase and tryptophan, an endogenous fluorophore in alpha-amylase. The presence of an emission peak at 345-355nm with excitation at 282nm could provide a strong presumptive indication of saliva deposition.

Fluorescence excitation spectroscopy provides information about human skin in vivo

Fluorescence spectroscopy of human skin has the potential to provide useful morphologic and biochemical information. The endogenous fluorescence of human skin has been investigated in vivo on normal human volunteers as well as on patients with psoriasis and it was found that characteristic bands can be identified in the fluorescence spectra that are associated with specific skin fluorophores. One epidermal band (295 nm excitation, attributed to tryptophan) and two dermal bands (335 and 370 nm excitation, attributed to collagen cross-links) were consistently present in all fluorescence spectra. In addition, the fluorescence spectra obtained from lesions and nonlesional sites of psoriatic patients differed from those obtained from healthy volunteers and the hyperproliferative state of the lesions was characterized by a significantly larger signal at 295 nm excitation. These results indicate that fluorescence spectroscopy is a promising technique for the investigation of human skin in vivo.

Endogenous skin fluorescence is a good marker for objective evaluation of comedolysis

OBJECTIVE

evaluation of comedone lesions, especially in vivo, remains a challenge. We have used the rhino mouse model in combination with topical application of all-trans retinoic acid as a comedolytic agent, to investigate the potential of fluorescence spectroscopy as a noninvasive technique in the assessment of noninflammatory acne. The results indicate that there is a strong correlation between the fluorescence excitation spectral features assessed in vivo, and the histologic changes identified, particularly the size of the utriculi as well as the dermal and epidermal thickness. We conclude that fluorescence excitation spectroscopy represents a promising novel and useful tool in the quantitative evaluation of the pseudocomedones and could also be used for the rapid and noninvasive assessment of comedolysis induced by the application of pharmacologic agents such as retinoids.

Microfine zinc oxide is a superior sunscreen ingredient to microfine titanium dioxide

BACKGROUND

Microfine zinc oxide and microfine titanium dioxide are particulate sunscreen ingredients that absorb broad-spectrum ultraviolet (UV) irradiation.

OBJECTIVE

We compare microfine zinc oxide and microfine titanium dioxide for their abilities to attenuate UVA radiation and their relative whiteness in cosmetic formulations.

METHODS

UVA attenuation was measured by diffuse reflectance spectroscopy on normal human skin in vivo. Whiteness was determined by reflectance density of dried coatings on a black background of the two particulates at varying concentrations.

RESULTS

Microfine zinc oxide demonstrates superior protection compared to microfine titanium dioxide in the UV spectrum between 340 and 380 nm. Microfine zinc oxide is less white than titanium dioxide at all concentrations.

CONCLUSION

Microfine zinc oxide is superior to microfine titanium dioxide as a sunscreen ingredient. It is more protective against long-wave UVA and is less white at a given concentration.

Spectroscopic determination of skin viability. A predictor of postmortem interval

We have demonstrated that skin viability decreases at a measurable rate following death in an animal model. The decreased skin viability was measured by fluorescein diacetate and ethidium bromide using fluorescence emission spectroscopy. There is significant decrease of the fluorescence intensity of the fluorescein diacetate assay between the 1-4 h, the 6-24 h, and the >40 h time points postmortem. For times between 6-24 h and >40 h postmortem the ethidium bromide assay showed consistent and significant increases in signal. The fluorescence measurements in this study showed that under the experimental conditions the time of death could be determined for <4, 6-24, and >40 hapotmotrem. The application of these assays in the field will require further study of the environmental factors.

Pharmacokinetics of doxepin in subjects with pruritic atopic dermatitis

BACKGROUND

Doxepin applied topically by itself or in combination with triamcinolone acetonide is a safe and effective treatment for atopic dermatitis.

OBJECTIVE

We evaluated the pharmacokinetic profile of doxepin and desmethyldoxepin after topical application of doxepin hydrochloride 5% cream alone or in combination with 0.025% triamcinolone acetonide (doxepin/TAC).

METHODS

Twenty-four subjects with atopic dermatitis received either doxepin or doxepin/TAC cream 4 times daily for 7 days in a randomized, double-blind, controlled trial. Serum samples were obtained and pharmacokinetic parameters estimated from the dose-normalized serum concentrations of doxepin and desmethyldoxepin. Efficacy and adverse experiences were determined by physician and subject evaluations.

RESULTS

Pharmacokinetic parameters (K(e ), t(1/2 ) and AUC) calculated in 9 subjects (doxepin/TAC = 4 subjects, doxepin = 5 subjects) with detectable serum concentrations were similar for both groups. Pruritus relief and lessening of pruritus severity were significantly greater with doxepin/TAC than doxepin alone.

CONCLUSION

Topically applied doxepin is safe and effective therapy for pruritus.

Endogenous skin fluorescence includes bands that may serve as quantitative markers of aging and photoaging

Aging and photoaging cause distinct changes in skin cells and extracellular matrix. Changes in hairless mouse skin as a function of age and chronic UVB exposure were investigated by fluorescence excitation spectroscopy. Fluorescence excitation spectra were measured in vivo, on heat-separated epidermis and dermis, and on extracts of mouse skin to characterize the absorption spectra of the emitting chromophores. Fluorescence excitation spectra obtained in vivo on 6 wk old mouse skin had maxima at 295, 340, and 360 nm; the 295 nm band was the dominant band. Using heat separated tissue, the 295 nm band predominantly originated in the epidermis and the bands at 340 and 360 nm originated in the dermis. The 295 nm band was assigned to tryptophan fluorescence, the 340 nm band to pepsin digestable collagen cross-links fluorescence and the 360 nm band to collagenase digestable collagen cross-links fluorescence. Fluorescence excitation maxima remained unchanged in chronologically aged mice (34-38 wk old), whereas the 295 nm band decreased in intensity with age and the 340 nm band increased in intensity with age. In contrast, fluorescence excitation spectra of chronically UVB exposed mice showed a large increase in the 295 nm band compared with age-matched controls and the bands at 340 and 350 nm were no longer distinct. Two new bands appeared in the chronically exposed mice at 270 nm and at 305 nm. These reproducible changes in skin autofluorescence suggest that aging causes predictable alterations in both epidermal and dermal fluorescence, whereas chronic UV exposure induces the appearance of new fluorphores.

Protoporphyrin IX fluorescence induced in basal cell carcinoma by oral delta-aminolevulinic acid

Limited depth of penetration significantly limits photodynamic therapy of nodular basal cell carcinoma (BCC) using topical delta (5)-aminolevulinic acid (ALA). To demonstrate safety and efficacy of orally administered ALA in inducing endogenous protoporphyrin IX (PpIX) production in BCC, 13 patients with BCC ingested ALA in a dose-escalation protocol. All dose ranges (10, 20 or 40 mg/kg single doses) resulted in formation of PpIX in human skin and BCC, measurable by in vivo fluorescence spectrophotometry. The PpIX fluorescence peaked in tumors before normal adjacent skin from 1 to 3 h after ALA ingestion. Gross fluorescence imaging of ex vivo specimens revealed greater PpIX fluorescence in tumor than normal skin only at the 40 mg/kg dose. Fluorescence microscopy confirmed this finding by showing distinct, full-thickness PpIX fluorescence in all subtypes of BCC only after ALA given at 40 mg/kg. Side effects were dose dependent and self limited. Photosensitivity lasting less than 24 h and nausea coinciding with peak skin PpIX fluorescence occurred at 20 and 40 mg/kg doses. After 40 mg/kg ALA, serum hepatic enzyme levels rose to a maximum within 24 h, then resolved over 1-3 weeks. Transient bilirubinuria occurred in two patients.

Protoporphyrin IX fluorescence induced in basal cell carcinoma by oral delta-aminolevulinic acid

Limited depth of penetration significantly limits photodynamic therapy of nodular basal cell carcinoma (BCC) using topical delta (5)-aminolevulinic acid (ALA). To demonstrate safety and efficacy of orally administered ALA in inducing endogenous protoporphyrin IX (PpIX) production in BCC, 13 patients with BCC ingested ALA in a dose-escalation protocol. All dose ranges (10, 20 or 40 mg/kg single doses) resulted in formation of PpIX in human skin and BCC, measurable by in vivo fluorescence spectrophotometry. The PpIX fluorescence peaked in tumors before normal adjacent skin from 1 to 3 h after ALA ingestion. Gross fluorescence imaging of ex vivo specimens revealed greater PpIX fluorescence in tumor than normal skin only at the 40 mg/kg dose. Fluorescence microscopy confirmed this finding by showing distinct, full-thickness PpIX fluorescence in all subtypes of BCC only after ALA given at 40 mg/kg. Side effects were dose dependent and self limited. Photosensitivity lasting less than 24 h and nausea coinciding with peak skin PpIX fluorescence occurred at 20 and 40 mg/kg doses. After 40 mg/kg ALA, serum hepatic enzyme levels rose to a maximum within 24 h, then resolved over 1-3 weeks. Transient bilirubinuria occurred in two patients.

Polarized light photography enhances visualization of inflammatory lesions of acne vulgaris

BACKGROUND

Polarized light photography has been used to selectively differentiate surface from subsurface features of photoaged skin.

OBJECTIVE

Our purpose was to compare acne assessments obtained from clinical evaluations with assessments from photographs obtained with flash photography and with perpendicular polarized light photography.

METHODS

Assessments of acne with the Cunliffe scale were made of 32 subjects. Retrospective evaluations of standard and perpendicular polarized light photographs were made in a blinded fashion by a panel of evaluators.

RESULTS

Visualization of inflammatory acne lesions was enhanced with perpendicular polarized light photography, with clear delineation of erythematous borders. Acne assessments with the use of a Cunliffe scale were significantly higher (p = 0.001) from perpendicular polarized light photographs than for clinical evaluations.

CONCLUSION

Polarized light photography enhances visualization of inflammatory acne lesions in a manner not possible with conventional flash photographs, permitting accurate evaluation of the extent of disease and the effectiveness of therapy.

American Academy of Dermatology guidelines of care. Development and process

Medical practice guidelines are being developed at an accelerating pace, in all areas of medicine, for a wide range of uses. The field of practice guideline development is not new, but a number of important economic and health care issues have renewed interest in their creation. In 1987, in response to many of these issues, the American Academy of Dermatology took a leadership role and began a process designed to develop guidelines for disease entities treated by dermatologists. The result was a set of clinical practice guidelines and the most comprehensive dermatology guideline development processes to date. Herein we describe the guideline development process in its current, refined form and discuss some of its unique and important characteristics. New applications of guidelines, outside of clinical practice improvement, have made their development controversial. Nevertheless, it is important for the medical profession to lead in this effort, and the American Academy of Dermatology continues to explore ways to refine and update its guidelines to reflect the latest medical science and technology.

Fluorescence photography in the evaluation of hyperpigmentation in photodamaged skin

BACKGROUND

Treatment-related changes in hyperpigmentation are difficult to quantify with visible light photography, especially when the changes are subtle.

OBJECTIVE

Our purpose was to determine the utility and reliability of fluorescence photography to measure changes in mottled and diffuse hyperpigmentation.

METHODS

Thirty-two subjects, with mildly to moderately photodamaged skin, completed a 36-week, double-blind, vehicle-controlled study of tretinoin cream 0.025%. Clinical evaluation of hyperpigmentation as well as standard flash photographs and fluorescence photographs were obtained at baseline and week 36.

RESULTS

The fluorescence photographs were evaluated blindly and yielded macule counts that decreased significantly from baseline in tretinoin-treated subjects compared with vehicle-treated subjects (31% vs 11% decrease; p = 0.02). Diffuse hyperpigmentation, as evaluated from the fluorescence photographs, decreased 16% from baseline for tretinoin-treated subjects and increased 5% for vehicle-treated subjects (p < 0.01). No significant differences in mottled or diffuse hyperpigmentation were observed between groups through clinical evaluation.

CONCLUSION

Fluorescence photography is a noninvasive method that is sensitive in the evaluation and quantification of distribution and changes of mottled and diffuse hyperpigmentation.

Oxyhemoglobin is a quantifiable measure of experimentally induced chronic tretinoin inflammation and accommodation in photodamaged skin

Chronic exposure to a weak irritant leads to inflammatory changes which may be followed by pigmentary changes and accommodation. The inflammatory responses to acute exposure to an irritant have been extensively studied. This study investigated quantitatively the inflammatory reactions produced in photodamaged skin with chronic application of a weak chemical irritant (tretinoin cream 0.025%) over a period of 9 months (36 weeks). Forty-eight subjects with moderately to severely photodamaged skin were enrolled in a 36-week, double-blind placebo-controlled study. Tretinoin cream was applied nightly on the distal two thirds of one dorsal forearm and placebo on the other. The proximal third of each dorsal forearm received no treatment and served as control. Clinical assessments and diffuse reflectance measurements were made at 7 time points during treatment. Apparent concentrations of oxyhemoglobin (HbO2), deoxyhemoglobin (Hb) and melanin were estimated by analysis of the diffuse reflectance spectra. No changes were observed in the apparent HbO2 or the Hb concentration of the placebo-treated or control sites, thus establishing a reliable baseline. The apparent HbO2 concentration of the tretinoin-treated sites increased significantly from baseline to a maximum at 12-18 weeks of treatment, then returned to baseline with continued applications. The changes in HbO2 concentration agreed closely with clinical assessments of erythema. The apparent melanin concentration, corresponding to diffuse hyperpigmentation, showed a large seasonal decrease in both the control and the treated sites, with an additional decrease in the treated sites between 12 and 18 weeks. Erythema appeared after repeated applications and eventually resolved under continuous treatment. The maximum decrease in hyperpigmentation occurred simultaneously with the maximum increase in erythema.

The future of Medicare. Their plans, your practice, Medicare reform, and how it will affect the practice of dermatology

The future of Medicare will be determined by patient demands, government action, and physician reactions. The federal government has always had the authority to design the Medicare program, but in the past physicians have had control over its implementation. While it is impossible to accurately predict the future, past and present reform efforts shed considerable light on directions the Medicare program will take and the impact Medicare will have on the science and practice of dermatology. It is important to understand these historic trends and the changes they foster to position ourselves to avoid threats and benefit from opportunities that will arise for the science and practice of dermatology.