Personalized pathology maps to quantify diffuse and focal brain damage

Background and objectives

Quantitative MRI (qMRI) permits the quantification of brain changes compatible with inflammation, degeneration and repair in multiple sclerosis (MS) patients. In this study, we propose a new method to provide personalized maps of tissue alterations and longitudinal brain changes based on different qMRI metrics, which provide complementary information about brain pathology.

Methods

We performed baseline and two-years follow-up on (i) 13 relapsing-remitting MS patients and (ii) four healthy controls. A group consisting of up to 65 healthy controls was used to compute the reference distribution of qMRI metrics in healthy tissue. All subjects underwent 3T MRI examinations including T1, T2, T2* relaxation and Magnetization Transfer Ratio (MTR) imaging. We used a recent partial volume estimation algorithm to estimate the concentration of different brain tissue types on T1 maps; then, we computed a deviation map (z-score map) for each contrast at both time-points. Finally, we subtracted those deviation maps only for voxels showing a significant difference with healthy tissue in one of the time points, to obtain a difference map for each subject.

Results and conclusion

Control subjects did not show any significant z-score deviations or longitudinal z-score changes. On the other hand, MS patients showed brain regions with cross-sectional and longitudinal concomitant increase in T1, T2, T2* z-scores and decrease of MTR z-scores, suggesting brain tissue degeneration/loss. In the lesion periphery, we observed areas with cross-sectional and longitudinal decreased T1/T2 and slight decrease in T2* most likely related to iron accumulation. Moreover, we measured longitudinal decrease in T1, T2 - and to a lesser extent in T2* - as well as a concomitant increase in MTR, suggesting remyelination/repair.

In summary, we have developed a method that provides whole-brain personalized maps of cross-sectional and longitudinal changes in MS patients, which are computed in patient space. These maps may open new perspectives to complement and support radiological evaluation of brain damage for a given patient.

Human Herpesvirus 6 and Malignancy: A Review

In order to determine the role of human herpesvirus 6 (HHV-6) in human disease, several confounding factors, including methods of detection, types of controls, and the ubiquitous nature of the virus, must be considered. This is particularly problematic in the case of cancer, in which rates of detection vary greatly among studies. To determine what part, if any, HHV-6 plays in oncogenesis, a review of the literature was performed. There is evidence that HHV-6 is present in certain types of cancer; however, detection of the virus within tumor cells is insufficient for assigning a direct role of HHV-6 in tumorigenesis. Findings supportive of a causal role for a virus in cancer include presence of the virus in a large proportion of cases, presence of the virus in most tumor cells, and virus-induced in-vitro cell transformation. HHV-6, if not directly oncogenic, may act as a contributory factor that indirectly enhances tumor cell growth, in some cases by cooperation with other viruses. Another possibility is that HHV-6 may merely be an opportunistic virus that thrives in the immunodeficient tumor microenvironment. Although many studies have been carried out, it is still premature to definitively implicate HHV-6 in several human cancers. In some instances, evidence suggests that HHV-6 may cooperate with other viruses, including EBV, HPV, and HHV-8, in the development of cancer, and HHV-6 may have a role in such conditions as nodular sclerosis Hodgkin lymphoma, gastrointestinal cancer, glial tumors, and oral cancers. However, further studies will be required to determine the exact contributions of HHV-6 to tumorigenesis.

Copy Number Heterogeneity, Large Origin Tandem Repeats, and Interspecies Recombination in Human Herpesvirus 6A (HHV-6A) and HHV-6B Reference Strains

Quantitative PCR is a diagnostic pillar for clinical virology testing, and reference materials are necessary for accurate, comparable quantitation between clinical laboratories. Accurate quantitation of human herpesvirus 6A/B (HHV-6A/B) is important for detection of viral reactivation and inherited chromosomally integrated HHV-6A/B in immunocompromised patients. Reference materials in clinical virology commonly consist of laboratory-adapted viral strains that may be affected by the culture process. We performed next-generation sequencing to make relative copy number measurements at single nucleotide resolution of eight candidate HHV-6A and seven HHV-6B reference strains and DNA materials from the HHV-6 Foundation and Advanced Biotechnologies Inc. Eleven of 17 (65%) HHV-6A/B candidate reference materials showed multiple copies of the origin of replication upstream of the U41 gene by next-generation sequencing. These large tandem repeats arose independently in culture-adapted HHV-6A and HHV-6B strains, measuring 1,254 bp and 983 bp, respectively. The average copy number measured was between 5 and 10 times the number of copies of the rest of the genome. We also report the first interspecies recombinant HHV-6A/B strain with a HHV-6A backbone and a >5.5-kb region from HHV-6B, from U41 to U43, that covered the origin tandem repeat. Specific HHV-6A reference strains demonstrated duplication of regions at U1/U2, U87, and U89, as well as deletion in the U12-to-U24 region and the U94/U95 genes. HHV-6A/B strains derived from cord blood mononuclear cells from different laboratories on different continents with fewer passages revealed no copy number differences throughout the viral genome. These data indicate that large origin tandem duplications are an adaptation of both HHV-6A and HHV-6B in culture and show interspecies recombination is possible within the Betaherpesvirinae.IMPORTANCE Anything in science that needs to be quantitated requires a standard unit of measurement. This includes viruses, for which quantitation increasingly determines definitions of pathology and guidelines for treatment. However, the act of making standard or reference material in virology can alter its very accuracy through genomic duplications, insertions, and rearrangements. We used deep sequencing to examine candidate reference strains for HHV-6, a ubiquitous human virus that can reactivate in the immunocompromised population and is integrated into the human genome in every cell of the body for 1% of people worldwide. We found large tandem repeats in the origin of replication for both HHV-6A and HHV-6B that are selected for in culture. We also found the first interspecies recombinant between HHV-6A and HHV-6B, a phenomenon that is well known in alphaherpesviruses but to date has not been seen in betaherpesviruses. These data critically inform HHV-6A/B biology and the standard selection process.

Lymphoproliferative Syndromes Associated with Human Herpesvirus-6A and Human Herpesvirus-6B

Human herpesvirus 6A and 6B (HHV-6A and HHV-6B) have been noted since their discovery for their T-lymphotropism. Although it has proven difficult to determine the extent to which HHV-6A and HHV-6B are involved in the pathogenesis of many diseases, evidence suggests that primary infection and reactivation of both viruses may induce or contribute to the progression of several lymphoproliferative disorders, ranging from benign to malignant and including infectious mononucleosis-like illness, drug induced hypersensitivity syndrome/drug reaction with eosinophilia and systemic symptoms (DIHS/DRESS), and nodular sclerosis Hodgkin's lymphoma. Herein, we discuss the conditions associated with the lymphoproliferative capacity of HHV-6, as well as the potential mechanisms behind them. Continued exploration on this topic may add to our understanding of the interactions between HHV-6 and the immune system and may open the doors to more accurate diagnosis and treatment of certain lymphoproliferative disorders.

A multi-contrast MRI study of microstructural brain damage in patients with mild cognitive impairment

Objectives

The aim of this study was to investigate pathological mechanisms underlying brain tissue alterations in mild cognitive impairment (MCI) using multi-contrast 3 T magnetic resonance imaging (MRI).

Methods

Forty-two MCI patients and 77 healthy controls (HC) underwent T1/T2* relaxometry as well as Magnetization Transfer (MT) MRI. Between-groups comparisons in MRI metrics were performed using permutation-based tests. Using MRI data, a generalized linear model (GLM) was computed to predict clinical performance and a support-vector machine (SVM) classification was used to classify MCI and HC subjects.

Results

Multi-parametric MRI data showed microstructural brain alterations in MCI patients vs HC that might be interpreted as: (i) a broad loss of myelin/cellular proteins and tissue microstructure in the hippocampus (p ≤ 0.01) and global white matter (p < 0.05); and (ii) iron accumulation in the pallidus nucleus (p ≤ 0.05). MRI metrics accurately predicted memory and executive performances in patients (p ≤ 0.005). SVM classification reached an accuracy of 75% to separate MCI and HC, and performed best using both volumes and T1/T2*/MT metrics.

Conclusion

Multi-contrast MRI appears to be a promising approach to infer pathophysiological mechanisms leading to brain tissue alterations in MCI. Likewise, parametric MRI data provide powerful correlates of cognitive deficits and improve automatic disease classification based on morphometric features.

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Forty-two MCI patients and 77 HC underwent multi-contrast quantitative MRI.

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MCI patients showed T1/T2* increase and MTR decrease in the hippocampus.

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MCI patients exhibited T1 increase in WM and T2* decrease in the pallidus.

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MRI metrics accurately predicted memory and executive function in patients.

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SVM classified MCI patients with 75% accuracy using volumetric/parametric MRI.

A multi-center study: intra-scan and inter-scan variability of diffusion spectrum imaging

The objective of this study was to investigate whether it is possible to pool together diffusion spectrum imaging data from four different scanners, located at three different sites. Two of the scanners had identical configuration whereas two did not. To measure the variability, we extracted three scalar maps (ADC, FA and GFA) from the DSI and utilized a region and a tract-based analysis. Additionally, a phantom study was performed to rule out some potential factors arising from the scanner performance in case some systematic bias occurred in the subject study. This work was split into three experiments: intra-scanner reproducibility, reproducibility with twin-scanner settings and reproducibility with other configurations. Overall for the intra-scanner and twin-scanner experiments, the region-based analysis coefficient of variation (CV) was in a range of 1%-4.2% and below 3% for almost every bundle for the tract-based analysis. The uncinate fasciculus showed the worst reproducibility, especially for FA and GFA values (CV 3.7-6%). For the GFA and FA maps, an ICC value of 0.7 and above is observed in almost all the regions/tracts. Looking at the last experiment, it was found that there is a very high similarity of the outcomes from the two scanners with identical setting. However, this was not the case for the two other imagers. Given the fact that the overall variation in our study is low for the imagers with identical settings, our findings support the feasibility of cross-site pooling of DSI data from identical scanners.

Temporal SNR characteristics in segmented 3D-EPI at 7T

Three-dimensional segmented echo planar imaging (3D-EPI) is a promising approach for high-resolution functional magnetic resonance imaging, as it provides an increased signal-to-noise ratio (SNR) at similar temporal resolution to traditional multislice 2D-EPI readouts. Recently, the 3D-EPI technique has become more frequently used and it is important to better understand its implications for fMRI. In this study, the temporal SNR characteristics of 3D-EPI with varying numbers of segments are studied. It is shown that, in humans, the temporal variance increases with the number of segments used to form the EPI acquisition and that for segmented acquisitions, the maximum available temporal SNR is reduced compared to single shot acquisitions. This reduction with increased segmentation is not found in phantom data and thus likely due to physiological processes. When operating in the thermal noise dominated regime, fMRI experiments with a motor task revealed that the 3D variant outperforms the 2D-EPI in terms of temporal SNR and sensitivity to detect activated brain regions. Thus, the theoretical SNR advantage of a segmented 3D-EPI sequence for fMRI only exists in a low SNR situation. However, other advantages of 3D-EPI, such as the application of parallel imaging techniques in two dimensions and the low specific absorption rate requirements, may encourage the use of the 3D-EPI sequence for fMRI in situations with higher SNR.

Comparison of physiological noise at 1.5 T, 3 T and 7 T and optimization of fMRI acquisition parameters

Previous studies have shown that under some conditions, noise fluctuations in an fMRI time-course are dominated by physiological modulations of the image intensity with secondary contributions from thermal image noise and that these two sources scale differently with signal intensity, susceptibility weighting (TE) and field strength. The SNR of the fMRI time-course was found to be near its asymptotic limit for moderate spatial resolution measurements at 3 T with only marginal gains expected from acquisition at higher field strengths. In this study, we investigate the amplitude of image intensity fluctuations in the fMRI time-course at magnetic field strengths of 1.5 T, 3 T, and 7 T as a function of image resolution, flip angle and TE. The time-course SNR was a similar function of the image SNR regardless of whether the image SNR was modulated by flip angle, image resolution, or field strength. For spatial resolutions typical of those currently used in fMRI (e.g., 3 x 3 x 3 mm(3)), increases in image SNR obtained from 7 T acquisition produced only modest increases in time-course SNR. At this spatial resolution, the ratio of physiological noise to thermal image noise was 0.61, 0.89, and 2.23 for 1.5 T, 3 T, and 7 T. At a resolution of 1 x 1 x 3 mm(3), however, the physiological to thermal noise ratio was 0.34, 0.57, and 0.91 for 1.5 T, 3 T and 7 T for TE near T2*. Thus, by reducing the signal strength using higher image resolution, the ratio of physiologic to image noise could be reduced to a regime where increased sensitivity afforded by higher field strength still translated to improved SNR in the fMRI time-series.

Complement C2 receptor inhibitor trispanning: a novel human complement inhibitory receptor

The complement system presents a powerful defense against infection and is tightly regulated to prevent damage to self by functionally equivalent soluble and membrane regulators. We describe complement C2 receptor inhibitor trispanning (CRIT), a novel human complement regulatory receptor, expressed on hemopoietic cells and a wide range of tissues throughout the body. CRIT is present in human parasites through horizontal transmission. Serum complement component C2 binds to the N-terminal extracellular domain 1 of CRIT, which, in peptide form, blocks C3 convertase formation and complement-mediated inflammation. Unlike C1 inhibitor, which inhibits the cleavage of C4 and C2, CRIT only blocks C2 cleavage but, in so doing, shares with C1 inhibitor the same functional effect, of preventing classical pathway C3 convertase formation. Ab blockage of cellular CRIT reduces inhibition of cytolysis, indicating that CRIT is a novel complement regulator protecting autologous cells.

The effect of an admixture of sodium hydrogen phosphate or heparin-coating to poly(D,L)lactide--results of an animal study

The study was aimed at investigating the effect of an admixture of sodium hydrogen phosphate (NaP) on the pH value around degrading poly(D,L)lactide (PDLLA) and the possible improvement of PDLLA biocompatibility by coating its surface with heparin. PDLLA +/- NaP was injection-molded to form rods (20 x 3 x 2 (mm)) and cubes (3 x 2 x 2 (mm)). Half of the pure PDLLA samples were surface-coated using heparin. One rod and cube each of PDLLA, PDLLA + NaP and PDLLA/Hep were implanted into the dorsal muscles of 42 rats. From the 2nd to 52nd week after operation, pH measurements were performed in the environment around the implants. The samples were then harvested for histological and mechanical analyses. No significant decrease in pH-values was observed in the tissue around the implants. Pure PDLLA and PDLLA/Hep samples were macroscopically resorbed after 52 weeks, while the degradation of PDLLA + NaP was still in progress. Approximately 80% of the initial bending strength of PDLLA or PDLLA/Hep rods was present after six weeks, while the bending strength of PDLLA + Nap was reduced to 50% after 4 weeks. Heparin-coating of PDLLA did not improve its biocompatibility but did increase its resorption. While no significant effect of NaP on pH value was found, its admixture did reduce the mechanical characteristics of the implants.

Immunologic aspects of chronic fatigue syndrome. Report on a Research Symposium convened by The CFIDS Association of America and co-sponsored by the US Centers for Disease Control and Prevention and the National Institutes of Health

Chronic fatigue syndrome (CFS) is a serious health concern affecting over 800,000 Americans of all ages, races, socioeconomic groups and genders. The etiology and pathophysiology of CFS are unknown, yet studies have suggested an involvement of the immune system. A symposium was organized in October 2001 to explore the possibility of an association between immune dysfunction and CFS, with special emphasis on the interactions between immune dysfunction and other abnormalities noted in the neuroendocrine and autonomic nervous systems of individuals with CFS. This paper represents the consensus of the panel of experts who participated in this meeting. Data suggest that persons with CFS manifest changes in immune responses that fall outside normative ranges, but current research does not provide definitive evidence on whether these immune abnormalities are a cause or result of the illness. It has become clear that CFS cannot be understood based on single measurements of immune, endocrine, cardiovascular, or autonomic nervous system dysfunction. This panel encourages a new emphasis on multidisciplinary research into CFS.

pH-stabilization of predegraded PDLLA by an admixture of water-soluble sodiumhydrogenphosphate--results of an in vitro- and in vivo-study

Aim of the study was to examine if the addition of buffering sodiumhydrogenphosphate to poly(D,L)lactide(PDLLA) would stabilize the pH-value in the in vivo environment of implanted material and whether this improves its biocompatibility. The material was predegraded just to the point of viscous disintegration to test the PDLLA in the moment of its most aggressive effect on the surrounding tissue. Racemic amorphous PDLLA was injection-molded with or without the admixture of 1 mol NaP per 100 mol lactate, the degradation product of PDLLA (=1 mol%) to form 20mm x 3 mm x 2mm rods. Predegradation was performed by storing the rods at 55 degrees C for 14 days, just to the point of beginning dissolution. Predegraded PDLLA or PDLLA + NaP samples were used for in vitro incubation tests, as well as for the in vivo study, where the rods were implanted into the spinal muscles of 30 male Wistar rats. Repeatedly, measurements of the pH-value were made in the incubation solutions in vitro. The surrounding tissue of the implanted samples as well as the normal contralateral muscle tissue was checked for its pH-value in a group of 3 rats, respectively, anaesthesized at various time intervals after implantation. After these measurements the implants and their surrounding tissues were excised for histological examination. In Ringer's solution pH-values dropped immediately within the first week of incubation of both predegraded materials reaching -4 pH units after 4 weeks in the PDLLA containing medium, after 6 weeks in the PDLLA + NaP containing medium. Soerensen buffer slowed the pH decrease with significant differences between the material groups up to the 28th week. In vivo, the pH of the surrounding tissue was influenced by the implanted PDLLA material up to the 4th week, while the admixture of NaP resulted in a significant pH stabilization. A higher quantity of macrophages and giant cells were seen between the 2nd and 6th week after the implantation in the environment of pure PDLLA compared with PDLLA + NaP. Complete resorption of predegraded pure PDLLA or PDLLA + NaP from the extracellular space was reached 28 weeks postimplantation in vivo. Thus, sodiumhydrogenphosphate improves the biocompatibility of degrading PDLLA at the point of viscous disintegration by stabilizing the pH-value in the environment of the implants for several weeks and reducing adverse tissue reactions.

The impact of psoriasis on quality of life: results of a 1998 National Psoriasis Foundation patient-membership survey

BACKGROUND

Psoriasis can have a profound impact on a patient's quality of life.

OBJECTIVES

To assess patients' perspectives on the impact of psoriasis on their lifestyle and emotional well-being and the social ramifications of living with the disease; to determine the range of therapies available; and to ascertain patients' satisfaction with the management of their disease.

DESIGN

A 4-page, self-administered questionnaire was mailed on July 13 and 14, 1998, to the entire membership of the National Psoriasis Foundation (N = 40 350), and followed by a telephone survey of responders with severe psoriasis.

MAIN OUTCOME MEASURES

Patients' perspectives on the psychosocial impact of psoriasis and the effectiveness of the management of their disease.

RESULTS

Of the 40 350 questionnaires mailed out, a response rate of 43% was realized. The most frequent symptoms experienced by the mail-survey respondents were scaling (94%), itching (79%), and skin redness (71%); 39% reported that psoriasis covered 10% or more of their bodies. A total of 6194 patients with severe psoriasis were entered into the database for the telephone survey. Of these, 79% reported that psoriasis had a negative impact on their lives, 40% felt frustrated with the ineffectiveness of their current therapies, and 32% reported that treatment was not aggressive enough.

CONCLUSIONS

The unprecedented response to the survey provides compelling evidence that individuals with psoriasis believe that the disease has a profound emotional and social as well as physical impact on their quality of life. Many patients with psoriasis, particularly those with severe disease, are frustrated with the management of their disease and by the perceived ineffectiveness of their therapies. Physicians may need to improve communication with their patients and should reevaluate their management of psoriasis.

CTLA4Ig-mediated blockade of T-cell costimulation in patients with psoriasis vulgaris

Engagement of the B7 family of molecules on antigen-presenting cells with their T cell-associated ligands, CD28 and CD152 (cytotoxic T lymphocyte-associated antigen-4 [CTLA-4]), provides a pivotal costimulatory signal in T-cell activation. We investigated the role of the CD28/CD152 pathway in psoriasis in a 26-week, phase I, open-label dose-escalation study. The importance of this pathway in the generation of humoral immune responses to T cell-dependent neoantigens, bacteriophage phiX174 and keyhole limpet hemocyanin, was also evaluated. Forty-three patients with stable psoriasis vulgaris received 4 infusions of the soluble chimeric protein CTLA4Ig (BMS-188667). Forty-six percent of all study patients achieved a 50% or greater sustained improvement in clinical disease activity, with progressively greater effects observed in the highest-dosing cohorts. Improvement in these patients was associated with quantitative reduction in epidermal hyperplasia, which correlated with quantitative reduction in skin-infiltrating T cells. No markedly increased rate of intralesional T-cell apoptosis was identified, suggesting that the decreased number of lesional T cells was probably likely attributable to an inhibition of T-cell proliferation, T-cell recruitment, and/or apoptosis of antigen-specific T cells at extralesional sites. Altered antibody responses to T cell-dependent neoantigens were observed, but immunologic tolerance to these antigens was not demonstrated. This study illustrates the importance of the CD28/CD152 pathway in the pathogenesis of psoriasis and suggests a potential therapeutic use for this novel immunomodulatory approach in an array of T cell-mediated diseases.

Cyclosporine consensus conference: with emphasis on the treatment of psoriasis

Cyclosporine has been in worldwide use for 15 years for patients who have undergone transplantation operations and is now being used to control inflammatory reactions in other organs (eg, joints, bowel, and skin). Neoral, a more consistently absorbed form of cyclosporine, has recently been approved by the Food and Drug Administration for the treatment of psoriasis. This report outlines the indications, contraindications, dosage recommendations, monitoring requirements, adverse events, drug interactions, interactions with other psoriasis treatments, and suggestions for cyclosporine's use in rotational therapy.

Dynamic NMR studies of perfusion and oxidative metabolism during focal brain activation

Together, the present results on oxygenation, flow, and metabolism indicate that the prevalence of nonoxidative glycolysis and associated lactate production during the initial phase of activation is replaced by the upregulation of oxidative glucose consumption (see sketches in Fig. 5). Following rapid circulatory changes the gap between oxygen availability and oxygen consumption gradually closes until a recoupling of perfusion and oxidative metabolism is achieved a few minutes after switching the state of neural activity. While brain glucose and lactate concentrations reflect an initial prevalence of anaerobic glycolysis, the changes in blood oxygenation suggest that the rapid adjustment of blood flow (enhanced oxygen delivery) is followed by a slower upregulation of oxidative metabolism (enhanced oxygen consumption). The physiological uncoupling of perfusion and oxidative metabolism emerges as a transient phenomenon in response to both onset and end of stimulation. Recoupling at enhanced cerebral metabolic rates of oxygen (CMRO2) and glucose occurs a few minutes after switching the state of neural activity. Since glycolysis takes place primarily in astrocytes, the stimulus-related increase and decrease of lactate seen here may reflect a transfer of astrocytic lactate to neurons where it is converted into pyruvate and channelled into oxidative phosphorylation. This model of metabolic responses to functional activation is supported by a recently detected pathway for glutamate-stimulated glycolysis in astrocytes that provides a simple mechanism linking astrocytic glucose utilization to neuronal activity (Pellerin and Magistretti, 1994). In summary, evidence has accumulated that the physiological uncoupling of perfusion and oxidative metabolism associated with the onset of functional activation is a transient phenomenon leading to an only temporal mismatch of oxygen delivery and consumption. Recoupling at enhanced though balanced levels of glucose and oxygen consumption is most remarkably documented by the pronounced "negative" uncoupling at the end of stimulation.

Quantitative determination of codeine and its major metabolites in human hair by gas chromatography-positive ion chemical ionization mass spectrometry: a clinical application

A highly sensitive method was developed for the quantitative analysis of codeine and morphine in human hair. After addition of deuterated internal standards, hair samples were digested overnight in 1N NaOH at 37 degrees C. Hydrolysis was performed on certain digests by addition of 1 mL 6N HCl. Digest solutions were extracted using a solid-phase procedure with Bond Elut Certify extraction columns. Derivatized extracts were analyzed on a Finnigan ion trap mass spectrometer (Magnum) in the positive ion chemical ionization mode using acetone as the reagent gas, helium as the carrier gas, and a DB-5 MS (30 m x 0.25-mm i.d.) capillary column. The assay was linear to 75 ng/mg (r = 0.99) and was capable of detecting 10 pg of codeine and morphine on-column. Intra-assay precision ranged from 8 to 20%. The method was used to quantitate codeine in human hair obtained from two male volunteers with dark brown to black hair after a single oral dose of 120 mg codeine phosphate liquid. Hair samples were plucked from the scalp for 28 days and then cut at the scalp. Codeine was detectable in 1-cm long hair (containing the bulb) at 12 h following the dose and remained detectable in the hair shaft for at least 8 weeks. Codeine metabolites were not detected in the hair of these two subjects. The method is currently being used in dose-response disposition studies to quantitate codeine and its major metabolites in human subjects.

Amyotrophic lateral sclerosis: is excitotoxicity the key?

Images

The Met/hepatocyte growth factor receptor (HGFR) gene is overexpressed in some cases of human leukemia and lymphoma

The proto-oncogene c-met encodes a heterodimeric (alpha, beta) tyrosine kinase receptor which binds the hepatocyte growth factor (HGF). Recently, overexpression of the Met/HGF receptor gene has been detected in fresh samples of carcinomas and in epithelial tumor cell lines but not in cell lines derived from human leukemia and lymphoma. Our analysis of 50 primary samples of human leukemia and lymphoma and 23 hematopoietic cell lines revealed expression of mRNA and protein of the met/HGF receptor in 6 out of the 73 hematopoietic tumor samples analyzed. Four of the six samples positive for expression of the Met/HGF receptor gene were derived from patients with Hodgkin's disease. In addition, in one Burkitt's lymphoma cell line and in one acute myeloid leukemia (AML), expression of the Met/HGF receptor gene was detected. In normal unstimulated lymphocytes, granulocytes or monocytes we did not find expression of the Met/HGF receptor gene. Upon stimulation with the phorbol ester TPA we detected a weak expression of Met/HGF receptor specific transcripts of 9.0 kb in peripheral blood mononuclear cells of a healthy donor. Cytogenetic analyses of three of the four cell lines which express the Met/HGF receptor gene revealed structural or numerical abnormalities of the long arm of chromosome 7, where the Met/HGFR gene is located, in each of the three cell lines analyzed. In one of these cell lines (L540) the Met/HGFR gene is translocated to a marker chromosome. Southern blot and pulsed field gel electrophoresis experiments did not show any rearrangement in a region of 600 kb around the Met/HGF receptor gene excluding an activation of Met/HGFR by a TPR/Met oncogenic rearrangement as described for MNNG-HOS cells and for some gastric tumors. Our data indicate that the Met/HGFR gene is deregulated in a few cases of human leukemia, Burkitt's lymphoma and Hodgkin's disease possibly by chromosomal rearrangements resulting in an overexpression of the normal Met/HGF receptor mRNA and protein without formation of a hybrid gene.

p53 and Ki 67 expression in preneoplastic and neoplastic lesions of the oral mucosa

Some lesions of the oral mucosa such as leukoplakia and erythroplakia may develop into squamous cell carcinoma (SCC). At present, however, there is no method available to predict malignant transformation. It is known that the grade of dysplasia is related to the potential malignant development, but this is unreliable as the only indicator. In 64 hyperplastic lesions and 85 SCC of the oral mucosa, a correlation between the expression of the mutated tumor-suppressor gene p53 and the dysplasia of the lesions was found. Ki 67 was used as a proliferation marker. The results imply that expression of mutated p53 is an indicator for potential malignant development in benign lesions of the oral mucosa.

A double-blind evaluation of topical capsaicin in pruritic psoriasis

BACKGROUND

Substance P, an undecapeptide neurotransmitter, has been implicated in the pathophysiology of psoriasis and pruritus.

OBJECTIVE

Safety and efficacy of topical capsaicin, a potent substance P depletor, were evaluated in patients with pruritic psoriasis.

METHODS

Patients applied capsaicin 0.025% cream (n = 98) or vehicle (n = 99) four times a day for 6 weeks in this double-blind study. Efficacy was based on a physician's global evaluation and a combined psoriasis severity score including scaling, thickness, erythema, and pruritus.

RESULTS

Capsaicin-treated patients demonstrated significantly greater improvement in global evaluation (p = 0.024 after 4 weeks and p = 0.030 after 6 weeks) and in pruritus relief (p = 0.002 and p = 0.060, respectively), as well as a significantly greater reduction in combined psoriasis severity scores (p = 0.030 and p = 0.036, respectively). The most frequently reported side effect in both treatment groups was a transient burning sensation at application sites.

CONCLUSION

Topically applied capsaicin effectively treats pruritic psoriasis, a finding that supports a role for substance P in this disorder.

Cysts associated with long-standing impacted third molars

Three patients are described in whom large cysts developed around third molars that had purposely been left in place. The cases presented emphasize the need for an adequate prospective study to evaluate the long-term morbidity of asymptomatic third molars that are left in place.

Analysis of c-myc, bcl-1 and bcl-2 translocations in human lymphoma by pulsed-field gel electrophoresis

Translocations of the c-myc, bcl-2 and the putative bcl-1 oncogene are recurrent events in B-cell lymphoma. Since it is likely that the rearranged genes contribute to the malignant phenotype of the tumor cells, such oncogene translocation is of major interest. The molecular detection of translocations using conventional Southern hybridization analysis is complicated by the fact that translocation breakpoints are dispersed over large chromosomal regions. In order to overcome this problem we used pulsed-field gel electrophoresis (PFGE) to detect c-myc, bcl-2 and bcl-1 translocations in 29 lymph node biopsies. C-myc translocation could not be detected in this group, either with standard Southern analysis of PFGE. Translocations of the bcl-2 gene were detected by PFGE in 5 samples and the breakpoints were mapped in all cases to the third exon of bcl-2 by standard Southern analysis. Furthermore, we also found rearrangements of the bcl-1 locus in 3 samples. Mapping of the breakpoint failed in one of these cases, which strongly indicates the existence of a breakpoint outside the bcl-1 major breakpoint region. Thus, PFGE allows the rapid detection of translocations in human lymphomas within large stretches of DNA.

Tactile function in skin-equivalent grafts

Cultured grafts are excellent wound covers; however, their somatosensory capabilities are unknown. This is a preliminary report of a study which determined whether grafts of cultured skin become innervated and also examined whether seeding grafts with target tissue improved nerve growth or functional recovery. Autologous skin for grafting was generated from adult rat biopsy tissue. Dissociated keratinocytes were seeded on top of fibroblast-contracted collagen gels (skin-equivalents). Some animals received grafts composed entirely of skin-equivalents. Others had grafts with 2-mm punch biopsies (normal skin or touch domes) inserted into them. Prior to sacrifice, whole nerve recordings of the cutaneous nerves supplying the grafts were made following tactile mechanical stimulation of the graft surfaces. Tissue was processed for light and electron microscopy as well as silver stained. Nerve fibers were present in the dermis (generated from the fibroblast contracted collagen gels) of all animals and often extended to the epidermis. Light brushing of the cultured areas of the grafts produced little or no activity in the cutaneous nerves; however, afferent impulses were generated after rubbing the skin with a glass rod or pinching it with fine forceps. The implanted regions within the skin-equivalents varied from this pattern. Lightly brushing their surface resulted in vigorous activity in the nerves. Elements in the skin therefore seemed to enhance nerve regeneration and function. However, the quality of the engraftment was also important. Implanted regions of grafts experiencing poor "takes" had compromised innervation.

[Difficulties in the diagnosis of AIDS-associated intrapulmonary Kaposi sarcoma]

Diagnosis of intrapulmonary Kaposi's sarcoma in HIV-infected patients may be extremely difficult. This is demonstrated in a case of a male patient with disseminated Kaposi's sarcoma and lethal pulmonary involvement. The value of various diagnostic procedures is discussed.

Treatment of condyloma acuminatum with three different interferons administered intralesionally. A double-blind, placebo-controlled trial

STUDY OBJECTIVE

To determine the efficacy and toxicity of intralesionally administered interferons in the treatment of condyloma acuminatum.

DESIGN

Randomized, double-blind, and placebo-controlled study.

SETTING

Outpatient clinics at university medical centers.

PATIENTS

Seventy-nine patients with biopsy-proved condyloma acuminatum that was refractory to conventional therapy were enrolled in the study.

INTERVENTIONS

Alpha-2b, alpha-nl-, and beta-interferons were used. One wart on each patients was injected three times per week for 4 weeks with either 1 x 10(6) units of interferon or placebo.

MEASUREMENTS AND MAIN RESULTS

Forty-seven percent of warts injected with interferon resolved completely, compared with 22% of placebo-injected warts (P = 0.009). In addition, more recipients of interferon had a complete resolution of uninjected lesions. No differences in rates of response were noted among the different interferon groups. Approximately one third of interferon-injected warts recurred, compared with none of four placebo-injected warts. Intralesionally administered interferon was nontoxic and well tolerated, although transient pain on injection was observed frequently.

CONCLUSIONS

Intralesional administration of each of these three interferons appears to be useful in treating condyloma acuminatum. However, the frequent recurrence of disease and the failure of many lesions to resolve indicate that different regimens, such as longer courses of therapy or different routes of administration, should be evaluated to maximize beneficial effects of interferon for treating this common sexually transmitted disease.

[Symptom of "urinary incontinence" as an indication of tubal cancer]

Discontinuous vaginal discharge in two patients, caused by a carcinoma of the fallopian tube, was misinterpreted as urinary incontinence for months. Complexes of atypical glandular epithelia in the cervico-vaginal smears and detection of adnexal tumors indicated the correct diagnosis.

Role of Epstein-Barr virus in acquired immune deficiency syndrome

We have reviewed the biologic characteristics, immune responses, and diverse array of diseases occurring from Epstein-Barr virus infections in immune deficient patients. We have summarized possible roles of the virus in the risk groups for AIDS. Data is convincing that EBV is responsible for some of the cases of lymphadenomegaly and Burkitt-like, non-Hodgkin's lymphomas in patients with pre-AIDS and AIDS. A hypothesis has been proposed wherein EBV and other stimulants of B and T cells allow productive infection by the retrovirus and spread of HTLV-III throughout the helper T cell populations.

Morbidity survey of U.S. oil shale workers employed during 1948-1969

The health status of 325 oil shale workers employed at the Anvil Points, Colorado, demonstration facility from 1948 to 1969 was evaluated. As a comparison population, 323 Utah coal miners frequency matched for age were studied. The prevalence of respiratory symptoms among oil shale workers who smoked were similar to the coal miners who smoked, although nonsmoking oil shale workers had fewer symptoms compared to nonsmoking coal workers. Four cases of skin cancers were found on the oil shale workers and eight cases in the controls. Similar numbers of nevi, telangiectasiae, possible pitch warts, pigment changes (solar/senile lentigo), and papillomata (seborrheic keratoses and skin tags) were seen in both groups, while actinic keratoses were more frequent in the oil shale workers. The prevalence of actinic keratoses was significantly associated with oil shale work after allowing for age, sun exposure, and other exposures. The prevalence of pulmonary cytology metaplasia was associated with years of production work in oil shale among both smokers and exsmokers. More of the oil shale workers had atypical cells in the urine, but the excess was mostly found among exsmokers. Although these workers had short-term and limited oil shale exposure work exposure, we recommend that medical surveillance of oil shale workers consider the skin, respiratory, and urinary systems for special observation.