Differential mechanisms underlie trace and delay conditioning in Drosophila

Two forms of associative learning-delay conditioning and trace conditioning-have been widely investigated in humans and higher-order mammals¹. In delay conditioning, an unconditioned stimulus (for example, an electric shock) is introduced in the final moments of a conditioned stimulus (for example, a tone), with both ending at the same time. In trace conditioning, a 'trace' interval separates the conditioned stimulus and the unconditioned stimulus. Trace conditioning therefore relies on maintaining a neural representation of the conditioned stimulus after its termination (hence making distraction possible²), to learn the conditioned stimulus-unconditioned stimulus contingency³; this makes it more cognitively demanding than delay conditioning⁴. Here, by combining virtual-reality behaviour with neurogenetic manipulations and in vivo two-photon brain imaging, we show that visual trace conditioning and delay conditioning in Drosophila mobilize R2 and R4m ring neurons in the ellipsoid body. In trace conditioning, calcium transients during the trace interval show increased oscillations and slower declines over repeated training, and both of these effects are sensitive to distractions. Dopaminergic activity accompanies signal persistence in ring neurons, and this is decreased by distractions solely during trace conditioning. Finally, dopamine D1-like and D2-like receptor signalling in ring neurons have different roles in delay and trace conditioning; dopamine D1-like receptor 1 mediates both forms of conditioning, whereas the dopamine D2-like receptor is involved exclusively in sustaining ring neuron activity during the trace interval of trace conditioning. These observations are similar to those previously reported in mammals during arousal⁵, prefrontal activation⁶ and high-level cognitive learning^7,8.

Expansion of immature, nucleated red blood cells by transient low-dose methotrexate immune tolerance induction in mice

Biological treatments such as enzyme-replacement therapies (ERT) can generate anti-drug antibodies (ADA), which may reduce drug efficacy and impact patient safety and consequently led to research to mitigate ADA responses. Transient low-dose methotrexate (TLD-MTX) as a prophylactic ITI regimen, when administered concurrently with ERT, induces long-lived reduction of ADA to recombinant human alglucosidase alfa (rhGAA) in mice. In current clinical practice, a prophylactic ITI protocol that includes TLD-MTX, rituximab and intravenous immunoglobulin (optional), successfully induced lasting control of ADA to rhGAA in high-risk, cross-reactive immunological material (CRIM)-negative infantile-onset Pompe disease (IOPD) patients. More recently, evaluation of TLD-MTX demonstrated benefit in CRIM-positive IOPD patients. To more clearly understand the mechanism for the effectiveness of TLD-MTX, non-targeted transcriptional and proteomic screens were conducted and revealed up-regulation of erythropoiesis signatures. Confirmatory studies showed transiently larger spleens by weight, increased spleen cellularity and that following an initial reduction of mature red blood cells (RBCs) in the bone marrow and blood, a significant expansion of Ter-119+ CD71+ immature RBCs was observed in spleen and blood of mice. Histology sections revealed increased nucleated cells, including hematopoietic precursors, in the splenic red pulp of these mice. This study demonstrated that TLD-MTX induced a transient reduction of mature RBCs in the blood and immature RBCs in the bone marrow followed by significant enrichment of immature, nucleated RBCs in the spleen and blood during the time of immune tolerance induction, which suggested modulation of erythropoiesis may be associated with the induction of immune tolerance to rhGAA.

Using supervised learning to select audit targets in performance-based financing in health: An example from Zambia

Independent verification is a critical component of performance-based financing (PBF) in health care, in which facilities are offered incentives to increase the volume of specific services but the same incentives may lead them to over-report. We examine alternative strategies for targeted sampling of health clinics for independent verification. Specifically, we empirically compare several methods of random sampling and predictive modeling on data from a Zambian PBF pilot that contains reported and verified performance for quantity indicators of 140 clinics. Our results indicate that machine learning methods, particularly Random Forest, outperform other approaches and can increase the cost-effectiveness of verification activities.

Deep(er) Learning

Animals successfully thrive in noisy environments with finite resources. The necessity to function with resource constraints has led evolution to design animal brains (and bodies) to be optimal in their use of computational power while being adaptable to their environmental niche. A key process undergirding this ability to adapt is the process of learning. Although a complete characterization of the neural basis of learning remains ongoing, scientists for nearly a century have used the brain as inspiration to design artificial neural networks capable of learning, a case in point being deep learning. In this viewpoint, we advocate that deep learning can be further enhanced by incorporating and tightly integrating five fundamental principles of neural circuit design and function: optimizing the system to environmental need and making it robust to environmental noise, customizing learning to context, modularizing the system, learning without supervision, and learning using reinforcement strategies. We illustrate how animals integrate these learning principles using the fruit fly olfactory learning circuit, one of nature's best-characterized and highly optimized schemes for learning. Incorporating these principles may not just improve deep learning but also expose common computational constraints. With judicious use, deep learning can become yet another effective tool to understand how and why brains are designed the way they are.

Measurement of the Neutrino Mixing Angle θ_{23} in NOvA

This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of 6.05×10^{20} protons on target from the NuMI beam at the Fermi National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal θ_{23} mixing (θ_{23}=π/4). Assuming the normal mass hierarchy, we find Δm_{32}^{2}=(2.67±0.11)×10^{-3}  eV^{2} and sin^{2}θ_{23} at the two statistically degenerate values 0.404_{-0.022}^{+0.030} and 0.624_{-0.030}^{+0.022}, both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6σ significance.

Cytomegalovirus viral load testing of blood using quantitative polymerase chain reaction in acutely unwell HIV-1-positive patients lacks diagnostic utility

We examined the usefulness of measuring cytomegalovirus (CMV) viral load (VL) in blood using quantitative polymerase chain reaction (qPCR) in establishing a diagnosis of CMV end-organ disease in consecutive unwell HIV-infected patients. The indication for testing for CMV, CD4 count, CMV VL and presence of CMV end-organ disease were abstracted from case-notes. During a 42-month period, 216 tests were performed in 181 patients; the majority (61%) had CD4 counts <100 cells/ μL. The prevalence of detectable CMV by qPCR was 43.5% (94/216) with a prevalence of CMV end-organ disease of 7.4% (16/216). Of patients with CMV detectable by qPCR, 72 % (50/69) had CD4 counts <100 cells/ μL. For patients with definite CMV end-organ disease, the positive predictive value of detectable CMV by qPCR was 10% (9/94), and the negative predictive value was 98% (119/122). In acutely unwell HIV-infected patients, detection of CMV by qPCR is a poor predictor of CMV end-organ disease.

Rectal gonorrhoea in men – is microscopy still a useful tool?

Rectal gonorrhoea (GC) in men may cause anal discharge or proctitis, but these symptoms have been shown to correlate poorly with rectal infection. Culture of Neisseria gonorrhoeae from an exposed site offers a readily available, sensitive and cheap diagnostic test, and is currently the gold standard for diagnosis; however, these results can take a few days and therefore do not offer an instant diagnosis. Gram staining of rectal smears for N. gonorrhoeae has a low sensitivity but a high specificity when performed by experienced personnel. We audited whether rectal microscopy increased the number of patients diagnosed and treated for rectal GC at initial presentation at one inner London genitourinary clinic over a 12-month period. One hundred and thirty-six episodes of rectal GC were identified in 132 men. In all, 134/136 had rectal microscopy of whom, 47/134 (35%) were smear-positive for GC. Of the 136 cases, 90 received antibiotics for GC at their first presentation. Twenty-four of 90 (27%) would not have been treated until culture results were available, if rectal microscopy had not been performed. These results suggest that rectal microscopy remains an important tool and increases the proportion of men treated for GC at their first attendance.

Herpes simplex virus infection of the central nervous system in human immunodeficiency virus-type 1-infected patients

We report clinical, radiological and virological data from nine consecutive HIV-infected patients with herpes simplex virus (HSV) infection of the central nervous system (CNS). Three patients presented with confusion, two with fever and headache, two with anxiety and depression, one with slow mentation and memory loss and one with expressive dysphasia. Five patients had previous AIDS-defining diagnoses: four of these five patients had previous cutaneous HSV infection. HSV DNA was detected by the polymerase chain reaction (PCR) on cerebrospinal fluid (CSF) in seven patients. HSV infection was diagnosed by brain biopsy (after negative PCR on CSF) in one patient and at autopsy in one patient (after negative CSF PCR and brain biopsy). Seven patients received specific anti-viral therapy; two died of unrelated causes and the other five recovered. Two patients were not treated, in one the diagnosis was made at autopsy and the other recovered spontaneously. HIV-infected patients with CNS HSV infection have a varied presentation. Diagnosis by PCR on CSF identified the majority of cases. With specific treatment the outcome was good.

Flyception: imaging brain activity in freely walking fruit flies

Genetically encoded calcium sensors have enabled monitoring of neural activity in vivo using optical imaging techniques. Linking neural activity to complex behavior remains challenging, however, as most imaging systems require tethering the animal, which can impact the animal's behavioral repertoire. Here, we report a method for monitoring the brain activity of untethered, freely walking Drosophila melanogaster during sensorially and socially evoked behaviors to facilitate the study of neural mechanisms that underlie naturalistic behaviors.

Hydrogen peroxide stimulates activity and alters behavior in Drosophila melanogaster

Circadian rhythms in animals are regulated at the level of individual cells and by systemic signaling to coordinate the activities of multiple tissues. The circadian pacemakers have several physiological outputs, including daily locomotor rhythms. Several redox-active compounds have been found to function in regulation of circadian rhythms in cells, however, how particular compounds might be involved in regulating specific animal behaviors remains largely unknown. Here the effects of hydrogen peroxide on Drosophila movement were analyzed using a recently developed three-dimensional real-time multiple fly tracking assay. Both hydrogen peroxide feeding and direct injection of hydrogen peroxide caused increased adult fly locomotor activity. Continuous treatment with hydrogen peroxide also suppressed daily locomotor rhythms. Conditional over-expression of the hydrogen peroxide-producing enzyme superoxide dismutase (SOD) also increased fly activity and altered the patterns of locomotor activity across days and weeks. The real-time fly tracking system allowed for detailed analysis of the effects of these manipulations on behavior. For example, both hydrogen peroxide feeding and SOD over-expression increased all fly motion parameters, however, hydrogen peroxide feeding caused relatively more erratic movement, whereas SOD over-expression produced relatively faster-moving flies. Taken together, the data demonstrate that hydrogen peroxide has dramatic effects on fly movement and daily locomotor rhythms, and implicate hydrogen peroxide in the normal control of these processes.

Pharmaceutical residues in wastewater treatment works effluents and their impact on receiving river water

Various pharmaceutical residues are being discharged from wastewater treatment works (WTW) effluents, the impact of which on river water quality is of high relevance to environmental risk assessment. The concentrations of eleven pharmaceutical compounds were determined in three WTWs in England, and the river Ouse receiving effluents from Scaynes Hill WTW. Results show that five compounds propranolol, sulfamethoxazole, carbamazepine, indomethacin and diclofenac were detected in all wastewater and river water samples, with carbamazepine showing the highest concentrations (up to 2336 ng L(-1)) in WTW influent. Different compounds were removed to different extent in the WTWs, varying from 43 to 92%, with the highest performance obtained by the WTW with tertiary treatment (sand filtration). The pharmaceutical residues from Scaynes Hill WTW were eventually discharged into the river Ouse, causing an elevation in their concentrations downstream of the outfall. This was confirmed by the good agreement between measured concentrations and those predicted by a simple dilution model.

Reduced glomerular filtration rate but sustained virologic response in HIV/hepatitis B co-infected individuals on long-term tenofovir

Reports have described a decrease in glomerular filtration rate (eGFR) associated with tenofovir disoproxil fumarate (TDF) use in HIV positive individuals. However, no study has examined renal function over a prolonged period in HIV/hepatitis B virus (HBV) co-infected patients. We assessed the long-term durability and toxicity of TDF in a cohort of 39 e antigen (eAg) positive co-infected patients commenced on TDF 245 mg daily either in addition to or as part of standard antiretroviral therapy. Immunological and virological parameters were followed to 260 weeks, with the median follow-up period being 251 weeks (range 69-290 weeks). eGFR was calculated using the Modification in Diet in Renal Disease equation. On treatment at 260 weeks, 88% (14/16) had HIV viral load <50 copies/mL, median CD4 count rose from 318 to 532 cells/mm(3), median alanine aminotransferase (ALT) fell from 61 IU/L to 42 IU/L, with 35% (7/20) having a normal ALT, median HBV DNA fell from 69 x 10(6) copies/mL to 500 copies/mL, with 75% (12/16) having an undetectable HBV DNA level and 55% (6/11) becoming eAg negative. Of those with detectable HBV DNA, none had TDF resistance mutations. The eGFR declined by 22.19 mL/min/1.73 mm(2) from baseline (P = 0.023) over this period, which was unaffected by protease inhibitor use, baseline CD4 count, ALT or HBV DNA level. Three patients discontinued TDF therapy due to renal dysfunction. In conclusion, TDF has sustained efficacy but is associated with a significant decline in eGFR. Further larger studies are required to clarify this observation.

Sexual health of adults working in pornographic films

We report the frequency of sexually transmitted infections (STIs) diagnosed in performers in the adult pornographic film industry. Over a 13 month period, 445 STI screens were performed in 115 patients, 56 women and 59 men. All reported unprotected sex during filming. Seventy-five percent (86) had at least one sexual partner outside work, and 90% used condoms inconsistently with them. Women worked exclusively with women (23%), men only (38%) or both genders (39%). Almost all men (97%) worked exclusively heterosexually. Thirty-eight percent (44/115) were diagnosed with 77 STIs, including non-specific urethritis (51), gonorrhoea (10), chlamydia (6) and genital warts (6). Gonorrhoea was found exclusively at the pharynx in three heterosexual men. There were no cases of HIV, syphilis, hepatitis B or hepatitis C. Monthly screening and certification is a working requirement for this population but STIs are common in an industry where unprotected sex is the norm.

Simultaneous tracking of movement and gene expression in multiple Drosophila melanogaster flies using GFP and DsRED fluorescent reporter transgenes

BACKGROUND

Fluorescent proteins such as GFP (Green Fluorescent Protein) and DsRED (Discosoma sp.Red Fluorescent Protein) are often used as reporter molecules for transgene expression in Drosophila and other species. We have recently reported methods that allow simultaneous tracking of animal movement and GFP expression in real time, however the assay was limited to single animals and a single transgene. Numerous studies would be facilitated by methods that allow for assay of multiple animals and multiple transgenes.

FINDINGS

Here we report an improved fly video tracking system that allows multiple transgenic flies to be tracked simultaneously using visible light, GFP fluorescence and DsRED fluorescence. The movement of multiple flies could be accurately tracked at real time rates, while simultaneously assaying the expression level of two different transgenes marked with GFP and DsRED. The individual flies could be accurately tracked and distinguished even during periods when transgene fluorescence was undetected. For example, characteristic patterns of hsp70 and hsp22 transgene induction could be simultaneously quantified and correlated with animal movement in aging flies, and as groups of flies died due to dessication/starvation.

CONCLUSION

The improved methods allow for more efficient assay of the correlation between gene expression, behavior, aging and mortality: multiple animals can be assayed with simultaneous quantification of multiple transgenes using GFP and DsRED fluorescence. These methods should allow for increased flexibility in experimental designs. For example, in the future it should be possible to use gene expression levels to predict remaining life span more accurately, and to quantify gene expression changes caused by interactions between animals in real time.

Simultaneous tracking of fly movement and gene expression using GFP

Background

Green Fluorescent Protein (GFP) is used extensively as a reporter for transgene expression in Drosophila and other organisms. However, GFP has not generally been used as a reporter for circadian patterns of gene expression, and it has not previously been possible to correlate patterns of reporter expression with 3D movement and behavior of transgenic animals.

Results

We present a video tracking system that allows tissue-specific GFP expression to be quantified and correlated with 3D animal movement in real time. eyeless/Pax6 reporter expression had a 12 hr period that correlated with fly activity levels.

hsp70 and hsp22 gene reporters were induced during fly aging in circadian patterns (24 hr and 18 hr periods, respectively), and spiked in the hours preceding and overlapping the death of the animal. The phase of hsp gene reporter expression relative to fly activity levels was different for each fly, and remained the same throughout the life span.

Conclusion

These experiments demonstrate that GFP can readily be used to assay longitudinally fly movement and tissue-specific patterns of gene expression. The hsp22-GFP and hsp70-GFP expression patterns were found to reflect accurately the endogenous gene expression patterns, including induction during aging and circadian periodicity. The combination of these new tracking methods with the hsp-GFP reporters revealed additional information, including a spike in hsp22 and hsp70 reporter expression preceding death, and an intriguing fly-to-fly variability in the phase of hsp70 and hsp22 reporter expression patterns. These methods allow specific temporal patterns of gene expression to be correlated with temporal patterns of animal activity, behavior and mortality.

O fly, where art thou?

In this paper, the design of a real-time image acquisition system for tracking the movement of Drosophila in three-dimensional space is presented. The system uses three calibrated and synchronized cameras to detect multiple flies and integrates the detected fly silhouettes to construct the three-dimensional visual hull models of each fly. We used an extended Kalman filter to estimate the state of each fly, given past positions from the reconstructed fly visual hulls. The results show that our approach constructs the three-dimensional visual hull of each fly from the detected image silhouettes and robustly tracks them at real-time rates. The system is suitable for a more detailed analysis of fly behaviour.

Intravitreal steroids for macular edema in diabetes

BACKGROUND

Macular edema is secondary to leakage from diseased retinal capillaries and is an important cause of poor central visual acuity in patients with diabetic retinopathy.

OBJECTIVES

This review evaluated the effectiveness and safety of intraocular steroids in treating diabetic macular edema (DME).

SEARCH STRATEGY

We searched CENTRAL, MEDLINE, EMBASE in June 2007, reference lists, Science Citation Index and conference proceedings.

SELECTION CRITERIA

We included randomized clinical trials (RCTs) evaluating any form of intravitreal steroids for treating DME.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed eligibility, methodological quality and extracted data. We performed meta-analyses when appropriate.

MAIN RESULTS

Seven studies, involving 632 DME eyes were included. Four examined the effectiveness of intravitreal triamcinolone acetate injection (IVTA), three examined intravitreal steroids implantation (fluocinolone acetonide implant (FAI) or dexamethasone drug delivery system (DDS)). Two trials were at low risk of bias, one was at median risk of bias, two were at high risk of bias and the remaining two were at unclear risk of bias. The preponderance of data suggest a beneficial effect from IVTA. Comparing IVTA with controls, the mean difference in visual acuity was -0.15 LogMAR (95% CI -0.21 to -0.09) at 3 months (based on three trials), -0.23 LogMAR (95% CI -0.33 to -0.13) at 6 months (two trials), -0.29 LogMAR (95% CI -0.47 to -0.11) at 9 months (one trial), and -0.11 LogMAR (95% CI -0.20 to -0.03) at 24 months (one trial), all in favor of IVTA. The relative risk (RR) for one or more lines improvement in visual acuity was 2.85 (95% CI 1.59 to 5.10) at 3 months (two trials), 1.25 (95% CI 0.66 to 2.38) at 6 months (one trial), and 2.17 (95% CI 1.15 to 4.11) at 24 months (one trial), all in favor of IVTA. We did not find evidence for three or more lines improvement in visual acuity. The mean difference in retinal thickness was -131.97 um (95% CI -169.08 to -94.86) at 3 months (two trials), -135.00 um (95% CI -194.50 to -75.50) at 6 months (one trial), -133.00 um (95% CI -199.86 to -66.14) at 9 months (one trial), and -59.00 um (95% CI -103.50 to -14.50) at 24 months (one trial), all in favor of IVTA. The RR for at least one grade macular edema resolution was 5.15 (95% CI 2.23 to 11.88) at 3 months in favor of IVTA (one trial). Two trials reported improved clinical outcome when FAI was compared to standard of care. Beneficial effect was also observed in one dexamethasone DDS trial. Increased intraocular pressure and cataract formation were side effects requiring monitoring and management.

AUTHORS' CONCLUSIONS

RCTs included in this review suggest that steroids placed inside the eye by either intravitreal injection or surgical implantation may improve visual outcomes in eyes with persistent or refractory DME. Since the studies in our report focused on chronic or refractory DME, the question arises whether intravitreal steroids therapy could be of value in other stages of DME, especially the earlier stages either as standalone therapy or in combination with other therapies, such as laser photocoagulation.

De novo hepatocellular carcinoma in a liver allograft associated with recurrent hepatitis B

Recurrent hepatocellular carcinoma is well described following liver transplantation. However, de novo hepatocellular carcinoma in the allograft is rare. We describe the clinical and pathological features of a case of de novo hepatocellular carcinoma arising in a cirrhotic allograft 9 years following transplantation for chronic hepatitis B.

Urinary catheter 'deflation cuff' formation: clinical audit and quantitative in vitro analysis

OBJECTIVE

To investigate reports from district nursing staff of difficulty in removing long-term urinary catheters (LTCs) because of the formation of a 'cuff' on deflating the self-retaining balloon.

PATIENTS AND METHODS

Problems experienced by district nurses when removing urethral and suprapubic LTCs were audited, noting the type of problem, the catheter and any action taken. Quantitative in vitro studies were conducted on the deflated self-retaining balloons after incubating a similar range of catheters in saline at 37 degrees C for 6 weeks, using suprapubic profilometry to assess the resistance to withdrawal (retention force).

RESULTS

Questionnaires were returned on 154 patients with LTCs; 56% had urethral and 44% suprapubic catheters. The catheters were hydrogel-coated (83%), all-silicone (13%) and PTFE-coated (3%). Twenty-two (14%) of the sample reported problems with catheter removal in the previous year, including 15 (68%) with all-silicone catheters and 15 (68%) with suprapubic catheters; cuff formation was noted in 60%. In the laboratory, 10 of the balloons formed a 'cuff' on deflation, but there was great variability in the effect this had on the retention force, with values of 0.5-3 N for different catheters.

CONCLUSIONS

Most problems with catheter removal involved all-silicone and suprapubic catheters. Suprapubic profilometry confirmed increased resistance to withdrawal by formation of a 'cuff' on deflation of the balloon of all-silicone catheters. These results suggest that the first choice of catheter material for long-term urethral and suprapubic use should be hydrogel-coated latex.

Transcriptional analysis of p30 major outer membrane multigene family of Ehrlichia canis in dogs, ticks, and cell culture at different temperatures

Ehrlichia canis, an obligatory intracellular bacterium of monocytes and macrophages, causes canine monocytic ehrlichiosis. E. canis immunodominant 30-kDa major outer membrane proteins are encoded by a polymorphic multigene family consisting of more than 20 paralogs. In the present study, we analyzed the mRNA expression of 14 paralogs in experimentally infected dogs and Rhipicephalus sanguineus ticks by reverse transcription-PCR using gene-specific primers followed by Southern blotting. Eleven out of 14 paralogs in E. canis were transcribed in increasing numbers and transcription levels, while the mRNA expression of the 3 remaining paralogs was not detected in blood monocytes of infected dogs during the 56-day postinoculation period. Three different groups of R. sanguineus ticks (adult males and females and nymphs) were separately infected with E. canis by feeding on the infected dogs. In these pools of acquisition-fed ticks as well as in the transmission-fed adult ticks, the transcript from only one paralog was detected, suggesting the predominant transcription of that paralog or the suppression of the remaining paralogs in ticks. Expression of the same paralog was higher whereas expression of the remaining paralogs was lower in E. canis cultivated in dog monocyte cell line DH82 at 25 degrees C than in E. canis cultivated at 37 degrees C. Analysis of differential expression of p30 multigenes in dogs, ticks, or monocyte cell cultures would help in understanding the role of these gene products in pathogenesis and E. canis transmission as well as in designing a rational vaccine candidate immunogenic against canine ehrlichiosis.

The measurement of premenstrual mood symptoms

INTRODUCTION

To aid in the diagnosis and management of premenstrual syndromes, dozens of symptom measurement instruments have been created and several methods for classifying clinically important change in symptoms have been defined. While the diagnosis of premenstrual dysphoric disorder (PMDD) has become standardized through the application of research criteria, consensus amongst investigators as to the instruments best able to confirm the diagnosis and measure treatment effects has yet to be reached.

OBJECTIVE

To determine the performance and inter-correlations of three prospective symptom rating scales used to establish severity of premenstrual mood symptoms and measure efficacy during a treatment trial for premenstrual dysphoria.

METHODS

Single item visual analogue scales (VASs) for irritability, tension, depression and mood swings were used in combination with the Premenstrual Tension Syndrome Observer (PMTS-O) and Self-Rating (PMTS-SR) scales to measure the severity of premenstrual mood symptoms at baseline and during treatment.

RESULTS

Premenstrual mood symptoms as measured by VASs significantly correlated with PMTS-0 and PMTS-SR scale scores (range 0.70 to 0.82, P < 0.001). All scales were sensitive to premenstrual symptom worsening (which is a required characteristic of this disorder) and revealed differences in effects of treatment on premenstrual mood symptoms (P < 0.001).

CONCLUSIONS

VASs in combination with the PMTS-O are low in burden to the client, reliable, valid and sensitive to change. In light of the current debates regarding instruments most appropriate for the classification and measurement of treatment effects in women diagnosed with premenstrual dysphoria, further refinement of these scales is warranted.

Compartment syndrome of the hand following intra-arterial injection of heroin

We report two cases of compartment syndrome of the hand and forearm, due to intra-arterial injection of heroin, managed by surgical fasciotomies alone. We also review the literature on the management of this condition.

Immunodetection of PrPSc in spleens of some scrapie-infected sheep but not BSE-infected cows

The development of diagnostic tools for transmissible spongiform encephalopathies (TSEs) would greatly assist their study and may provide assistance in controlling the disease. The detection of an abnormal form of the host protein PrP in noncentral nervous system tissues may form the basis for diagnosis of TSEs. Using a new antibody reagent to PrP produced in chickens, PrP can be readily detected in crude tissue extracts. PrP from uninfected spleen had a lower molecular mass range than PrP from brain, suggesting a lower degree of glycosylation. A simple method for detecting the abnormal form of the protein, PrPSc, in ruminant brain and spleen has been developed. PrPSc was detected in sheep spleen extracts from a flock affected by natural scrapie and was also found in spleens from some, but not all, experimental TSE cases. In spleens from cattle with bovine spongiform encephalopathy (BSE) no PrPSc was detected. It is therefore suggested that there is differential targeting of PrPSc deposition between organs in these different types of TSE infection which, with other factors, depends on strain of infecting agent.

Fluoxetine in the treatment of premenstrual dysphoria. Canadian Fluoxetine/Premenstrual Dysphoria Collaborative Study Group

BACKGROUND

Premenstrual dysphoria shares certain features with depression and anxiety states, which have been linked to serotonergic dysregulation. We evaluated the efficacy and safety of fluoxetine (which selectively inhibits the reuptake of serotonin) in the treatment of premenstrual dysphoria.

METHODS

The trial consisted of a single-blind, placebo washout period lasting two menstrual cycles, followed by a randomized, double-blind, placebo-controlled trial of fluoxetine at a dose of either 20 mg or 60 mg per day or placebo for six menstrual cycles. Healthy women meeting criteria for what was then called late-luteal-phase dysphoric disorder were recruited at seven university-affiliated women's health clinics in Canada. The primary outcome measure consisted of visual-analogue scales for tension, irritability, and dysphoria during the late luteal phase of each cycle.

RESULTS

Of 405 women enrolled in the placebo washout period, 313 subsequently entered the randomized phase of the study, which lasted six menstrual cycles, and 180 completed it. Fluoxetine at a dose of 20 or 60 mg per day was significantly superior to placebo in reducing symptoms of tension, irritability, and dysphoria, as measured by the visual-analogue scales (P < 0.001). The women who received 60 mg of fluoxetine per day reported significantly more side effects than those who received 20 mg per day or placebo (P < 0.001).

CONCLUSIONS

Fluoxetine is useful in the treatment of premenstrual dysphoria. Treatment with fluoxetine at a dose of 20 mg per day reduces the potential for side effects while maximizing therapeutic efficacy.

Transplantation of Y79 cells into rat eyes: an in vivo model of human retinoblastomas

PURPOSE

To develop an in vivo model of human retinoblastoma by returning cultured Y79 retinoblastoma cells to the retinal environment of a widely available laboratory animal. In so doing, to study the survival, integration, and invasive characteristics expressed by tumoral cells grafted into an intraocular milieu from which these progenitor cells originated more than 20 years ago.

METHODS

Using the retinal grafting method of Lazar and del Cerro, Y79 cells were injected under direct visualization into the subretinal space of Fischer 344 rats. The host rats included 36 animals that received daily injections of cyclosporin A and 4 that did not. All hosts were sacrificed 30 to 60 days after transplantation.

RESULTS

Clinical examination showed vitreal invasion by masses of flocculent white material or the intravitreal formation of solid tumors. Histologic examination showed these formations to be outgrowths of grafted tumoral cells into the host retina and vitreal cavity. Highly anaplastic tumoral cells were also found lodged in subretinal and intraretinal locations. There were signs of continued and intense cell division within the grafts, with no indication of cell-mediated host reaction against the grafted cells.

CONCLUSIONS

After intraretinal xenografting, human Y79 retinoblastoma cells retain a highly tumoral nature despite many years of in vitro propagation. When xenografted, these cells survive, grow, and express their malignancy within the retina of the common laboratory rat protected by a moderate immunosuppressive regimen. This partial immunosuppression is a requirement for the xenografts to prosper. This model offers a valuable opportunity to study in vivo the cellular and molecular biology of this and other human retinoblastomas, and it may facilitate the evaluation of antitumoral treatments.

Improvement of phencyclidine-associated psychosis with ECT

Phencyclidine-associated psychosis may mimic classic forms of both schizophrenia and affective psychosis. Treatment of phencyclidine-associated psychosis may prove very difficult for some patients. A patient who developed a severe phencyclidine-associated psychosis and failed to respond to high doses of antipsychotics is described. The patient responded dramatically to electroconvulsive therapy.

Congenital retinitis in the rat following maternal exposure to lymphocytic choriomeningitis virus

A combined clinical and histopathological study of the eyes of the offspring of females inoculated with LCMV shows that about two-thirds of the pups develop some degree of retinal inflammation. This may range from a mild, subclinical reaction to an overt retinitis characterized clinically by demonstrable inflammatory and degenerative changes. Histopathologically, the latter condition presents the picture of an inflammatory reaction with extensive loss of photoreceptors and retinal neurons in general, macrophagic invasion, mild microcystoid degeneration and total or subtotal retinal detachment. This vertically-transmitted disease does not show the relentless progression and hemorrhagic tendency characteristic of the retinitis which occurs after direct viral inoculation. However, in the most severe cases the final outcome is the same, namely severe retinal impairment subsequent to widespread loss of photoreceptors. In the presence of consistently negative virological data, the hypothesis is proposed that this retinitis could be the result of a vertically-transmitted autoimmune disease.

A cellulose acetate electrophoretic procedure evaluated for quantitation of high-density lipoprotein cholesterol

We evaluated the performance of a commercially available cellulose acetate electrophoretic method for quantitating high-density lipoprotein cholesterol (I) in serum by comparing it to a method involving precipitation with dextran sulfate-500/Mg2+. In both methods, enzymic reagents are used for cholesterol measurement. For electrophoretic measurement of I the mean intramembrane CV ws 4.1% (at 220 to 360 mg/L) and the intermembrane CV ranged from 12.2 to 21.0% (at 220 to 880 mg/L). Interassay precision was significantly better for the precipitation method (CV = 3.9% at 390 mg/L). The electrophoretic procedure demonstrated significant measurement bias, both at high and low I concentrations. However, low-density lipoprotein cholesterol, measured electrophoretically correlated well with its calculated concentrations obtained by the precipitation method. Measurement of I by this electrophoretic procedure did not achieve the accuracy and reproducibility that have been demonstrated for precipitation methods and that are necessary for reliable clinical interpretation of results for I.

A cellulose acetate electrophoretic procedure evaluated for quantitation of high-density lipoprotein cholesterol

We evaluated the performance of a commercially available cellulose acetate electrophoretic method for quantitating high-density lipoprotein cholesterol (I) in serum by comparing it to a method involving precipitation with dextran sulfate-500/Mg2+. In both methods, enzymic reagents are used for cholesterol measurement. For electrophoretic measurement of I the mean intramembrane CV ws 4.1% (at 220 to 360 mg/L) and the intermembrane CV ranged from 12.2 to 21.0% (at 220 to 880 mg/L). Interassay precision was significantly better for the precipitation method (CV = 3.9% at 390 mg/L). The electrophoretic procedure demonstrated significant measurement bias, both at high and low I concentrations. However, low-density lipoprotein cholesterol, measured electrophoretically correlated well with its calculated concentrations obtained by the precipitation method. Measurement of I by this electrophoretic procedure did not achieve the accuracy and reproducibility that have been demonstrated for precipitation methods and that are necessary for reliable clinical interpretation of results for I.