Sleep-wake behavior and responses to sleep deprivation and immune challenge of protein kinase RNA-activated knockout mice.

Protein Kinase RNA-activated (PKR) is an enzyme that plays a role in many systemic processes, including modulation of inflammation, and is implicated in neurodegenerative diseases, such as Alzheimer's disease (AD). PKR phosphorylation results in the production of several cytokines involved in the regulation / modulation of sleep, including interleukin-1ß, tumor necrosis factor-α and interferon-γ. We hypothesized targeting PKR would alter spontaneous sleep of mice, attenuate responses to sleep deprivation, and inhibit responses to immune challenge. To test these hypotheses, we determined the sleep-wake phenotype of mice lacking PKR (knockout; PKR-/-) during undisturbed baseline conditions; in responses to six hours of sleep deprivation; and after immune challenge with lipopolysaccharide (LPS). Adult male mice (C57BL/6J, n = 7; PKR-/-, n = 7) were surgically instrumented with EEG recording electrodes and an intraperitoneal microchip to record core body temperature. During undisturbed baseline conditions, PKR -/- mice spent more time in non-rapid eye movement sleep (NREMS) and rapid-eye movement sleep (REMS), and less time awake at the beginning of the dark period of the light:dark cycle. Delta power during NREMS, a measure of sleep depth, was less in PKR-/- mice during the dark period, and core body temperatures were lower during the light period. Both mouse strains responded to sleep deprivation with increased NREMS and REMS, although these changes did not differ substantively between strains. The initial increase in delta power during NREMS after sleep deprivation was greater in PKR-/- mice, suggesting a faster buildup of sleep pressure with prolonged waking. Immune challenge with LPS increased NREMS and inhibited REMS to the same extent in both mouse strains, whereas the initial LPS-induced suppression of delta power during NREMS was greater in PKR-/- mice. Because sleep regulatory and immune responsive systems in brain are redundant and overlapping, other mediators and signaling pathways in addition to PKR are involved in the responses to acute sleep deprivation and LPS immune challenge.

Abundant cytomegalovirus (CMV) reactive clonotypes in the CD8(+) T cell receptor alpha repertoire following allogeneic transplantation.

Allogeneic stem cell transplantation is potentially curative, but associated with post-transplantation complications, including cytomegalovirus (CMV) infections. An effective immune response requires T cells recognizing CMV epitopes via their T cell receptors (TCRs). Little is known about the TCR repertoire, in particular the TCR-α repertoire and its clinical relevance in patients following stem cell transplantation. Using next-generation sequencing we examined the TCR-α repertoire of CD8(+) T cells and CMV-specific CD8(+) T cells in four patients. Additionally, we performed single-cell TCR-αß sequencing of CMV-specific CD8(+) T cells. The TCR-α composition of human leucocyte antigen (HLA)-A*0201 CMVpp65- and CMVIE -specific T cells was oligoclonal and defined by few dominant clonotypes. Frequencies of single clonotypes reached up to 11% of all CD8(+) T cells and half of the total CD8(+) T cell repertoire was dominated by few CMV-reactive clonotypes. Some TCR-α clonotypes were shared between patients. Gene expression of the circulating CMV-specific CD8(+) T cells was consistent with chronically activated effector memory T cells. The CD8(+) T cell response to CMV reactivation resulted in an expansion of a few TCR-α clonotypes to dominate the CD8(+) repertoires. These results warrant further larger studies to define the ability of oligoclonally expanded T cell clones to achieve an effective anti-viral T cell response in this setting.

Alzheimer's disease drug discovery: in vivo screening using Caenorhabditis elegans as a model for ß-amyloid peptide-induced toxicity.

Alzheimer's disease (AD) is a complex human neurodegenerative disease. Currently the therapeutics for AD only treats the symptoms. While numbers of excellent studies have used mammalian models to discover new compounds, the time and effort involved with screening large numbers of candidates is prohibitive. Cultured mammalian neurons are often used to perform high-throughput screens (HTS); however, cell culture lacks the organismal complexity involved in AD. To address these issues several researchers are turning to the roundworm, Caenorhabditis elegans. C. elegans has numerous models of both Tau and Ab induced toxicity, the two prime components observed to correlate with AD pathology. These models have led to the discovery of numerous AD modulating candidates. Further, the ease of performing RNA interference for any gene in the C. elegans genome allows for identification of proteins involved in the mechanism of drug action. These attributes make C. elegans well positioned to aid in the discovery of new AD therapies.

Implementation of a piritramide based patient-controlled analgesia (PCA) as a standard of care for pain control in late abortion induction: A prospective cohort study from a patient perspective.

Objective: To assess whether the implementation of patient-controlled analgesia (PCA) with piritramide using an automatic pump system under routine conditions is effective to reduce pain in late abortion inductions. Study design: Prospective observational cohort study. Setting: Patients requiring medically indicated abortion induction from 14 weeks of pregnancy onwards between July 2019 and July 2020 at the department of Obstetrics and Prenatal Medicine of the Bonn University Hospital in Germany. Methods: Evaluation of pain management after implementation of a PCA system compared with previous nurse-controlled tramadol-based standard under routine conditions. Patients answered a validated pain questionnaire and requirement of rescue analgesics was assessed. Pain intensity and satisfaction were measured on a ten-point numeric rating scale. Main Outcome Measure Maximal pain intensity. Results: Forty patients were included. Patients using Piritramide-PCA complained of higher pain sores than those in the standard group (6.90 (± 2.34) vs. 4.83 (± 2.87), (p < 0.05)). In both groups the level of satisfaction with the analgesia received was comparable (8.00 (± 2.45) vs 7.67 (± 2.62), (p = 0.7)). Patients in the PCA group suffered more nausea (63.2 % vs 30 % respectively, OR 4.0, 95 % CI 1.05-15.20, p < 0.05) and expressed more the desire for more analgesic support compared to the control group (OR 5.7 (1-33.25), p = 0.05). Conclusion: Women with abortion induction after 14 weeks of gestation suffer from relevant severe pain, which requires adequate therapy. However, addition of PCA does not seem to bring any advantage in patients undergoing this procedure.

A diagnostic support system based on pain drawings: binary and k-disease classification of EDS, GBS, FSHD, PROMM, and a control group with Pain2D.

BACKGROUND AND OBJECTIVE: The diagnosis of rare diseases (RDs) is often challenging due to their rarity, variability and the high number of individual RDs, resulting in a delay in diagnosis with adverse effects for patients and healthcare systems. The development of computer assisted diagnostic decision support systems could help to improve these problems by supporting differential diagnosis and by prompting physicians to initiate the right diagnostic tests. Towards this end, we developed, trained and tested a machine learning model implemented as part of the software called Pain2D to classify four rare diseases (EDS, GBS, FSHD and PROMM), as well as a control group of unspecific chronic pain, from pen-and-paper pain drawings filled in by patients. METHODS: Pain drawings (PDs) were collected from patients suffering from one of the four RDs, or from unspecific chronic pain. The latter PDs were used as an outgroup in order to test how Pain2D handles more common pain causes. A total of 262 (59 EDS, 29 GBS, 35 FSHD, 89 PROMM, 50 unspecific chronic pain) PDs were collected and used to generate disease specific pain profiles. PDs were then classified by Pain2D in a leave-one-out-cross-validation approach. RESULTS: Pain2D was able to classify the four rare diseases with an accuracy of 61-77% with its binary classifier. EDS, GBS and FSHD were classified correctly by the Pain2D k-disease classifier with sensitivities between 63 and 86% and specificities between 81 and 89%. For PROMM, the k-disease classifier achieved a sensitivity of 51% and specificity of 90%. CONCLUSIONS: Pain2D is a scalable, open-source tool that could potentially be trained for all diseases presenting with pain.

Changes in hoof health and animal hygiene in a dairy herd after covering concrete slatted floor with slatted rubber mats: a case study.

The objective was to investigate the effect of changing the flooring in the alleys of a barn from slatted concrete to slatted rubber mats on hoof disorders and animal hygiene in 44 loose-housed Brown Swiss dairy cows. Cows were examined for disorders of the hind hooves (hemorrhages, white line fissures, ulcers, heel horn erosion, and digital dermatitis) and for skin lesions. The dirtiness of the animals and of the floor was recorded. Climatic (temperature, humidity) and ammonia gas conditions were measured. Evaluations were carried out when the cows were housed on a concrete slatted floor and after 4 and 10 mo on soft flooring (slatted rubber mats, 29-mm thick). The anatomical portion of claw (medial, lateral), number of lactations (parity), and days in milk were included as covariates in the statistical model. Changing the flooring from slatted concrete to slatted rubber mats increased the score for white line fissures [1.0 ± 0.3 (concrete) vs. 2.5 ± 0.4 (10 mo rubber mats)] and influenced air humidity (i.e., the difference in the absolute humidity between the inside and outside of the barn increased from 1.5 ± 0.1 to 1.7 ± 0.2g/m(3)), whereas the other hoof disorders, skin lesions (score of 8.7 ± 0.3), the dirtiness of the animals (score of 5.9 ± 0.3), and the floor (score of 2.1 ± 0.1), and ammonia gas concentration (2.6 ± 0.3mg/kg) were not affected (overall scores or measures; mean ± SE). Lateral claws were more affected (except for heel horn erosion) than medial claws (estimated effects between 1.3 ± 0.2 and 3.0 ± 0.6). Parity influenced hoof disorders (except for hemorrhages) and skin lesions (estimated effects between -0.6 ± 0.3 and 0.5 ± 0.2). Days in milk influenced hoof disorders, but had no effect on skin lesions and on the dirtiness of the animal. Irrespective of floor type, the slots (2.6 ± 0.1) were dirtier than the slats (1.6 ± 0.1). In conclusion, covering slatted concrete flooring with slatted rubber mats partially impaired hoof health but did not influence skin lesions or the dirtiness of the cows or the floor. Similar results were found for climatic conditions, as ammonia gas concentration was not affected, but absolute humidity increased in the barn when rubber mats were present.

Mineralocorticoid receptor blockade attenuates chronic overexpression of the renin-angiotensin-aldosterone system stimulation of reduced nicotinamide adenine dinucleotide phosphate oxidase and cardiac remodeling.

The renin-angiotensin-aldosterone system contributes to cardiac remodeling, hypertrophy, and left ventricular dysfunction. Angiotensin II and aldosterone (corticosterone in rodents) together generate reactive oxygen species (ROS) via reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, which likely facilitate this hypertrophy and remodeling. This investigation sought to determine whether cardiac oxidative stress and cellular remodeling could be attenuated by in vivo mineralocorticoid receptor (MR) blockade in a rodent model of the chronically elevated tissue renin-angiotensin-aldosterone system, the transgenic TG (mRen2) 27 rat (Ren2). The Ren2 overexpresses the mouse renin transgene with resultant hypertension, insulin resistance, proteinuria, and cardiovascular damage. Young (6- to 7-wk-old) male Ren2 and age-matched Sprague-Dawley rats were treated with spironolactone or placebo for 3 wk. Heart tissue ROS, immunohistochemical analysis of 3-nitrotyrosine, and NADPH oxidase (NOX) subunits (gp91(phox) recently renamed NOX2, p22(phox), Rac1, NOX1, and NOX4) were measured. Structural changes were assessed with cine-magnetic resonance imaging, transmission electron microscopy, and light microscopy. Significant increases in Ren2 septal wall thickness (cine-magnetic resonance imaging) were accompanied by perivascular fibrosis, increased mitochondria, and other ultrastructural changes visible by light microscopy and transmission electron microscopy. Although there was no significant reduction in systolic blood pressure, significant improvements were seen with MR blockade on ROS formation and NOX subunits (each P < 0.05). Collectively, these data suggest that MR blockade, independent of systolic blood pressure reduction, improves cardiac oxidative stress-induced structural and functional changes, which are driven, in part, by angiotensin type 1 receptor-mediated increases in NOX.

Sources of variation in physician adherence with clinical guidelines: results from a factorial experiment.

BACKGROUND: Health services research has documented the magnitude of health care variations. Few studies focus on provider level sources of variation in clinical decision making-for example, which primary care providers are likely to follow clinical guidelines, with which types of patient. OBJECTIVES: To estimate: (1) the extent of primary care provider adherence to practice guidelines and the unconfounded influence of (2) patient attributes and (3) physician characteristics on adherence with clinical practice guidelines. DESIGN: In a factorial experiment, primary care providers were shown clinically authentic video vignettes with actors portrayed different "patients" with identical signs of coronary heart disease (CHD). Different types of providers were asked how they would manage the different "patients" with identical CHD symptoms. Measures were taken to protect external validity. RESULTS: Adherence to some guidelines is high (over 50% of physicians would follow a third of the recommended actions), yet there is low adherence to many of them (less than 20% would follow another third). Female patients are less likely than males to receive 4 of 5 types of physical examination (p < .03); older patients are less likely to be advised to stop smoking (p < .03). Race and SES of patients had no effect on provider adherence to guidelines. A physicians' level of experience (age) appears to be important with certain patients. CONCLUSIONS: Physician adherence with guidelines varies with different types of "patient" and with the length of clinical experience. With this evidence it is possible to appropriately target interventions to reduce health care variations by improving physician adherence with clinical guidelines.

DNA repair defects associated with chromosomal translocation breaksite regions.

Using an assay that measures the removal of UV-induced pyrimidine dimers in specific DNA sequences, we have found that the Pvt-1, immunoglobulin H-C alpha (IgH-C alpha), and IgL-kappa loci are poorly repaired in normal B lymphoblasts from plasmacytoma-susceptible BALB/cAnPt mice. Breaksites in these genes are associated with the chromosomal translocations that are found in > 95% of BALB/cAnPt plasmacytomas. In contrast to those from BALB/cAnPt mice, B lymphoblasts from plasmacytoma-resistant DBA/2N mice rapidly repair Pvt-1, IgH-C alpha, and IgL-kappa. Further, (BALB/cAnPt x DBA/2N)F1 hybrids, which are resistant to plasmacytoma development, carry an efficient (DBA/2N-like) repair phenotype. Analysis of allele-specific repair in the IgH-C alpha locus indicates that efficient repair is controlled by dominant, trans-acting factors. In the F1 heterozygotes, these factors promote efficient repair of BALB/cAnPt IgH-C alpha gene sequences. The same sequences are poorly repaired in the BALB/cAnPt parental strain. Analysis of the strand specificity of repair indicates that both strand-selective and nonselective forms of repair determine repair efficiency at the gene level in nonimmortalized murine B lymphoblasts.

Increased gene-specific repair of cisplatin interstrand cross-links in cisplatin-resistant human ovarian cancer cell lines.

We have studied several aspects of DNA damage formation and repair in human ovarian cancer cell lines which have become resistant to cisplatin through continued exposure to the anticancer drug. The resistant cell lines A2780/cp70 and 2008/c13*5.25 were compared with their respective parental cell lines, A2780 and 2008. Cells in culture were treated with cisplatin, and the two main DNA lesions formed, intrastrand adducts and interstrand cross-links, were quantitated before and after repair incubation. This quantitation was done for total genomic lesions and at the level of individual genes. In the overall genome, the initial frequency of both cisplatin lesions assayed was higher in the parental than in the derivative resistant cell lines. Nonetheless, the total genomic repair of each of these lesions was not increased in the resistant cells. These differences in initial lesion frequency between parental and resistant cell lines were not observed at the gene level. Resistant and parental cells had similar initial frequencies of intrastrand adducts and interstrand cross-links in the dihydrofolate reductase (DHFR) gene and in several other genes after cisplatin treatment of the cells. There was no increase in the repair efficiency of intrastrand adducts in the DHFR gene in resistant cell lines compared with the parental partners. However, a marked and consistent repair difference between parental and resistant cells was observed for the gene-specific repair of cisplatin interstrand cross-links. DNA interstrand cross-links were removed from three genes, the DHFR, multidrug resistance (MDR1), and delta-globin genes, much more efficiently in the resistant cell lines than in the parental cell lines. Our findings suggest that acquired cellular resistance to cisplatin may be associated with increased gene-specific DNA repair efficiency of a specific lesion, the interstrand cross-link.

Retroviral transfer and expression of a humanized, red-shifted green fluorescent protein gene into human tumor cells.

Over two-thirds of the current gene therapy protocols use retroviral gene transfer systems. We have developed an efficient retroviral-based method that allows rapid identification of gene transfer in living mammalian cells. Cells were generated containing a gene for an improved (humanized, red-shifted) version of the Aequorea victoria green fluorescent protein (hRGFP) from a retroviral vector. The hRGFP gene was used to produce an amphotropic vector producer cell line that demonstrated vibrant green fluorescence after excitation with blue light. A375 melanoma cells transduced with the retroviral vector demonstrated stable green fluorescence. Both PA317 murine fibroblasts and A375 human cell lines containing the vector were easily detected by FACS analysis. These vectors represent a substantial improvement over currently available gene transfer marking systems. Bright, long-term expression of the hRGFP gene in living eukaryotic cells will advance the study of gene transfer, gene expression, and gene product function in vitro and in vivo particularly for human gene therapy applications.

Dose-intense taxol: high response rate in patients with platinum-resistant recurrent ovarian cancer.

BACKGROUND: Paclitaxel (Taxol), a diterpene plant product that promotes tubulin polymerization, has documented activity against a number of solid tumors, including ovarian cancer and breast cancer. PURPOSE: Our purpose was to conduct a phase II clinical trial investigating the response of patients with advanced recurrent ovarian carcinoma to high-dose paclitaxel combined with granulocyte colony-stimulating factor (G-CSF). METHODS: A prospective phase II clinical trial of patients with advanced-stage, recurrent ovarian cancer was undertaken. Patients received 250 mg/m2 paclitaxel every 21 days; cycles were given on a rigid schedule; delays were permitted only for extreme circumstances. G-CSF at a dose of 10 micrograms/kg per day was given to ameliorate myelo-suppression. If a patient showed fever and neutropenia, G-CSF dosage was increased to 20 micrograms/kg per day so that paclitaxel dose intensity could be maintained. Patients were assessed for response every two cycles, and those with complete radiographic resolution of disease underwent peritoneoscopy. RESULTS: Forty-four patients were assessable for response. Twenty-one had a reduction in tumor volume greater than 50%, yielding an objective response rate of 48% (21 of 44 patients; 95% confidence interval, 32%-63%). Six (14%) of the 44 patients had complete radiographic resolution of disease; two of the six also had negative biopsy specimens and washings at peritoneoscopy. Age, number of prior regimens, and clinical platinum resistance did not influence response rate or ability to maintain dose intensity. Dose intensity was maintained at the targeted level for up to 14 consecutive cycles of therapy. CONCLUSIONS: We observed a 48% response rate with dose-intense paclitaxel for patients with advanced-stage, platinum-resistant, recurrent ovarian cancer. The response rate is higher than previously reported for paclitaxel at a lower dose in similar cohorts of patients treated without G-CSF. Comparison of phase II studies of paclitaxel suggests a dose-response relationship. Therapy with dose-intense paclitaxel and G-CSF should be considered for patients with advanced, platinum-refractory ovarian cancer.

Radioisotope concentrator gene therapy using the sodium/iodide symporter gene.

We demonstrate a novel method of concentrating radiation for tumor imaging or killing. The rat sodium/iodide symporter gene (rNIS) was cloned into a retroviral vector for transfer into cancer cells to mimic the iodide uptake of thyroid follicular cells. In vitro iodide transport shows that the symporter functions similarly in rNIS-transduced tumor cells and rat thyroid follicular cells. rNIS-transduced and control nontransduced (NV) human A375 melanoma xenografts established in vivo in athymic nude mice were imaged using a gamma camera after i.p. injections of 123I. The rNIS-transduced human A375 melanoma tumors are visually distinguishable from and accumulate significantly more radionuclides than NV tumors. In vitro clonogenic assays confirm efficacy and clearly show that rNIS-transduced A375 human melanoma, BNL.1 ME murine transformed liver, CT26 murine colon carcinoma, and IGROV human ovarian carcinoma can be selectively killed by the induced accumulation of 131I. Thus, NIS-based gene therapy may have both diagnostic and therapeutic applications for cancer.

Clinical investigation of a cytostatic calcium influx inhibitor in patients with refractory cancers.

Carboxyamido-triazole (CAI) is a synthetic inhibitor of non-excitable calcium channels that reversibly inhibits angiogenesis, tumor cell proliferation, and metastatic potential. Inhibition of calcium influx and calcium-dependent events is a potential common mechanism underlying these effects of CAI. The cytostatic and antiangiogenic properties of CAI led to its development for clinical investigation. In a Phase I clinical trial open to patients with refractory solid tumors, 49 patients received p.o. administered CAI daily or every other day. Two oral formulations, PEG-400 CAI solution and a gelatin capsule containing CAI in PEG-400, were tested. All administered dosages of CAI yielded plasma concentration at or above the range demonstrated to be effective in inhibiting signaling and cancer progression in vitro and in preclinical models (1 microgram/ml, 2.3 microM). Toxicity of p.o. administered CAI most commonly consisted of dose-related grade 1-2 nausea, vomiting, and occasional anorexia. CAI administration at bedtime ameliorated gastrointestinal complaints in many patients; others required addition of simple antiemetic regimens, usually consisting of metoclopropamide or prochlorperazine. Gastrointestinal complaints were the cause for compliance-limiting toxicity at 175 mg/m2/day of the liquid formulation and 125 mg/m2/day of the gelatin capsule formation. Reversible and rare sensory axonal neuropathy (grade 3, 1 patient) and neutropenia (grade 4, 1 patient) were dose-limiting toxicities observed at the 330 mg/m2 every-other-day liquid CAI dose level. No evidence of cumulative end organ damage or central nervous system injury was observed. Disease stabilization and improvement in performance status was observed. Disease stabilization and improvement in performance status was observed in 49% of evaluable patients who had disease progression before CAI. Disease stabilization and associated improvement in performance status was seen in patients with renal cell carcinoma (7 months), pancreaticobiliary carcinomas (3, 5, and 5 months), melanoma (7 months), ovarian cancer (7 months), and non-small cell lung cancer (3 months). The recommended Phase II doses from this trial are 150 mg/m2/day in the liquid formation and 100 mg/m2/day in the gelatin capsule formation.

Durable responses to ibrutinib in patients with relapsed CLL after allogeneic stem cell transplantation.

Ibrutinib, a recently approved inhibitor of Bruton's tyrosine kinase (BTK), has shown great efficacy in patients with high-risk CLL. Nevertheless, there are few data regarding its use in patients who relapsed after allogeneic stem cell transplantation (alloSCT). We report clinical data from five CLL patients treated with ibrutinib for relapse after first or even second allogeneic transplantation. Additionally, we performed analyses on cytokine levels and direct measuring of CD4 Th1 and CD4 Th2 cells to evaluate possible clinically relevant immunomodulatory effects of ibrutinib. All patients achieved partial responses including one minimal residual disease (MRD)-negative remission. Within 1 year of follow-up, no relapse was observed. One patient died of severe pneumonia while on ibrutinib treatment. Beside this, no unexpected adverse events were observed. Flow cytometry and analyses of T cell-mediated cytokine levels (IL10 and TNFα) did not reveal substantial changes in T-cell distribution in favor of a CD4 Th1 T-cell shift in our patients. No acute exacerbation of GvHD was reported. In conclusion, these results support further evaluation of ibrutinib in CLL patients relapsing after alloSCT.

DNA repair in the endogenous and episomal amplified c-myc oncogene loci in human tumor cells.

We have studied the repair of u.v.-induced cyclobutane pyrimidine dimers (CPDs) in amplified c-myc oncogene loci in human colon cancer cells to better understand the relationship between chromatin structure, transcription and DNA repair. To assess the variation in DNA repair in the same gene whether located in a chromosomal site or in a extra-chromosomal site, we have quantitated the efficiency of excision repair after u.v. exposure in the endogenous and episomal c-myc genes isolated from COLO320HSR and DM cells. In the HSR cells, c-myc is localized in a homogeneously staining region (HSR), and in the DM cells, the gene is localized in double minute chromosomes (DM). Our results indicate that the repair is less efficient in c-myc amplicons organized as double minute chromosomes than in the endogenous c-myc amplicons. The episomal gene is not repaired with the same efficiency as when it is intrachromosomal. This may reflect differences in chromatin structure. An advantage of this biological system is that the cells possess two different alleles of the c-myc gene, one that is active and another which is inactive. We have studied the relationship between DNA repair and transcriptional activity in the c-myc locus by measuring the efficiency of excision repair after u.v. exposure in the normal and rearranged alleles of the c-myc gene. Surprisingly, the c-myc gene is repaired with similar efficiency in the highly transcribed allele as in the poorly expressed allele. However, u.v. damage is selectively removed from the transcribed strand of the active c-myc allele, but DNA repair is not strand specific in the non-expressed c-myc allele.

Invertebrate models of Alzheimer's disease.

The intensely studied model organisms Caenorhabditis elegans and Drosophila melanogaster have been employed to study a number of neurodegenerative diseases, including Alzheimer's disease (AD). Although worms and flies are phylogenetically distant from humans, results of both classic genetic analyses and transgenic manipulation of these invertebrates suggest they are valid models for at least some aspects of AD. This review describes the rationale for AD-relevant studies in worms and flies and discusses both what has been learned from these studies and what may be discovered in the future.

Genetic Evidence of Unusual Meiosis in the Dinoflagellate CRYPTHECODINIUM COHNII.

Genetic analysis of the homothallic dinoflagellate, Crypthecodinium cohnii, using 16 nonallelic motility mutants, revealed (1) virtual absence of second division segregation and (2) independent assortment of all genes except for: (a) three cases of cross specific, "false" linkage and (b) one possible case of linkage with a high percentage of crossing over. The probability that at least two of the 16 genes studied are on one of the approximately 50 (minimal) chromosomes is extremely high and, since recombination is observed between all pairs of markers, it is highly probable that some results from crossing over. This likelihood plus the observed absence of second division segregation and the significant number of two-celled zygotic cysts support the view that the "meiosis" of C. cohnii is a one-division process.

Characterization of Caenorhabditis elegans lectin-binding mutants.

We have identified 45 mutants of Caenorhabditis elegans that show ectopic surface binding of the lectins wheat germ agglutinin (WGA) and soybean agglutinin (SBA). These mutations are all recessive and define six genes: srf-2, srf-3, srf-4, srf-5, srf-8 and srf-9. Mutations in these genes fall into two phenotypic classes: srf-2, -3, -5 mutants are grossly wild-type, except for their lectin-binding phenotype; srf-4, -8, -9 mutants have a suite of defects, including uncoordinated movement, abnormal egg laying, and defective copulatory bursae morphogenesis. Characterization of these pleiotropic mutants at the cellular level reveals defects in the migration of the gonadal distal tip cell and in axon morphology. Unexpectedly, the pleiotropic mutations also interact with mutations in the lin-12 gene, which encodes a putative cell surface receptor involved in the control of cell fate. We propose that the underlying defect in the pleiotropic mutations may be in the general processing or secretion of extracellular proteins.

Quetiapine in patients with schizophrenia. A high- and low-dose double-blind comparison with placebo. Seroquel Study Group.

BACKGROUND: Quetiapine fumarate (Seroquel [ICI 204,636]) is an atypical dibenzothiazepine antipsychotic with a greater affinity for 5-hydroxytryptamine2 (5-HT2) receptors than for D2 dopamine receptors; its efficacy in patients with schizophrenia was shown in early phase 2 trials (maximum dose, 750 mg/d). METHODS: In this multicenter, double-blind, placebo-controlled trial, 286 patients hospitalized with chronic or subchronic schizophrenia (DSM-III-R) were randomized to 6 weeks of treatment with high-dose quetiapine fumarate (< or = 750 mg/d), n = 96; low-dose quetiapine fumarate (< or = 250 mg/d), n = 94; or placebo, n = 96. The Brief Psychiatric Rating Scale (BPRS) and Clinical Global Impression Severity of Illness item scores were the primary efficacy variables. Secondary efficacy variables included the BPRS positive-symptom cluster score, the Modified Scale for the Assessment of Negative Symptoms summary score (United States only), and the total score from the negative scale of the Positive and Negative Syndrome Scale (Europe only). Scores were analyzed using an analysis of covariance for change from baseline at end point with last observations carried forward. The model included baseline score (covariate), center, and treatment. Extrapyramidal symptoms were assessed using the Simpson-Angus Scale and the Barnes Akathisia Scale; abnormal involuntary movements were assessed using the Abnormal Involuntary Movement Scale. Frequency distributions of grouped change-from-baseline scores were analyzed using chi 2 tests. RESULTS: Of 280 patients in whom the efficacy of quetiapine was evaluated, 159 (42% of those receiving high-dose treatment; 57%, low-dose treatment; and 59%, placebo) withdrew before trial completion, primarily because of treatment failure. Significant (P < .001, BPRS; P = .003, Clinical Global Impression Severity of Illness item; and P = .003, BPRS positive-symptom cluster) differences were identified between patients receiving high-dose quetiapine and placebo for both primary efficacy variables, with end point differences in the BPRS positive-symptom cluster score showing quetiapine's consistency in reducing positive symptoms. The reduction of negative symptoms was less consistent; high-dose quetiapine was superior on the Modified Scale for the Assessment of Negative Symptoms but not on the negative scale of the Positive and Negative Syndrome Scale. Quetiapine was well tolerated and did not induce extrapyramidal symptoms, sustained elevations of prolactin, or clinically significant changes in hematologic parameters. CONCLUSIONS: Quetiapine is an effective antipsychotic with a favorable safety profile. The optimum dose is probably greater than 250 mg/d.