Treatment-related changes in insomnia, anticipatory pleasure, and depression symptoms: A proof-of-concept study with cancer survivors

OBJECTIVE/BACKGROUND

Cancer survivors have elevated rates of insomnia and depression. Insomnia increases risk for depression onset, and the Integrated Sleep and Reward (ISR) Model suggests that impairments in reward responding (e.g., ability to anticipate and/or experience pleasure) plays a central role in this relationship. Cognitive behavioral therapy for insomnia (CBT-I) is efficacious for treating chronic insomnia and reducing depression in cancer survivor populations. The effects of CBT-I on anticipatory and consummatory pleasure are theoretically and clinically meaningful, yet remain unexamined.

PATIENTS/METHODS

This secondary analysis of a pilot RCT (N = 40 cancer survivors with insomnia) explicated changes in anticipatory and consummatory pleasure and depression symptoms following a 4-session, synchronous, virtual CBT-I program versus enhanced usual care (referral to a behavioral sleep medicine clinic + sleep hygiene handout). Linear mixed models examined changes in anticipatory and consummatory pleasure and depression symptoms as predictors of changes in insomnia severity from baseline to post-intervention and 1-month follow-up.

RESULTS

CBT-I buffered against deterioration in anticipatory pleasure but not consummatory pleasure or depression symptoms. Across conditions, increased anticipatory pleasure was associated with insomnia reduction through 1-month follow-up, even after adjusting for changes in depression symptoms.

CONCLUSION

CBT-I may improve reward processing deficits in cancer survivors with insomnia. Findings provide support for the ISR Model and implicate pleasure as an important target for insomnia and depression.

The Survivorship Sleep Program (SSP): A synchronous, virtual cognitive behavioral therapy for insomnia pilot program among cancer survivors

BACKGROUND

For cancer survivors, insomnia is prevalent, distressing, and persists for years if unmanaged. Cognitive behavioral therapy for insomnia (CBT-I) is an effective treatment yet can be difficult to access and may require modification to address survivorship-specific barriers to sleep. In this 2-phase study, the authors adapted and assessed the feasibility, acceptability, and preliminary effects of synchronous, virtual CBT-I adapted for cancer survivors (the Survivorship Sleep Program [SSP]).

METHODS

From April to August 2020, cancer survivors with insomnia (N = 10) were interviewed to refine SSP content and delivery. From October 2020 to March 2021, 40 survivors were recruited for a randomized controlled trial comparing 4 weekly SSP sessions with enhanced usual care (EUC) (CBT-I referral plus a sleep hygiene handout). Feasibility and acceptability were assessed by enrollment, retention, attendance, fidelity, survey ratings, and exit interviews. Insomnia severity (secondary outcome), sleep quality, sleep diaries, and fatigue were assessed at baseline, postintervention, and at 1-month follow-up using linear mixed models.

RESULTS

The SSP included targeted content and clinician-led, virtual delivery to enhance patient centeredness and access. Benchmarks were met for enrollment (56% enrolled/eligible), retention (SSP, 90%; EUC, 95%), attendance (100%), and fidelity (95%). Compared with EUC, the SSP resulted in large, clinically significant improvements in insomnia severity (Cohen d = 1.19) that were sustained at 1-month follow-up (Cohen d = 1.27). Improvements were observed for all other sleep metrics except sleep diary total sleep time and fatigue.

CONCLUSIONS

Synchronous, virtually delivered CBT-I targeted to cancer survivors is feasible, acceptable, and seems to be efficacious for reducing insomnia severity. Further testing in larger and more diverse samples is warranted.

Including Distal Motor Function within the NIHSS: Correlation with Motor Arm Function and IV rt-PA Treatment Response

OBJECTIVES

The Distal Motor Function (DMF) sub-score of the NIH Stroke Scale (NIHSS) was measured in the NINDS rt-PA Stroke Trials but is currently not included in the NIHSS. The correlation of DMF with the NIHSS Motor Arm Function (MAF) sub-score, the effect of IV tPA treatment on DMF, and whether adding DMF changes the utility of the NIHSS have not been analyzed.

MATERIALS AND METHODS

MAF and DMF sub-scores were retrieved from the original NINDS rt-PA Stroke Trials for both sides of the body at baseline, 2 hours, 24 hours, 7-10 days, and 3 months after IV tPA treatment. MAF and DMF scores were correlated using Spearman correlation. Clustering of DMF and MAF scores was determined using a Bentler Comparative Fit Index (CFI) to estimate variation in NIHSS when adding DMF. The effect of IV tPA on DMF and MAF was assessed using a linear model comparing changes in scores from baseline to 3 months.

RESULTS

MAF and DMF were highly correlated (p < 0.0001) across all time points for both dichotomous and continuous data on both sides. Intravenous tPA accounted for 21% of the change in DMF (p < 0.014, R² = 0.0157, N = 423) and 39% of the change in MAF (p < 0.093, R² = 0.0125, N = 547) from 0 to 3 months. On adding DMF to NIHSS, CFI decreased from 0.98 to 0.80 and DMF clustered with MAF, indicating that addition of DMF is unlikely to produce any discrepancy to NIHSS.

CONCLUSIONS

Including DMF to the NIHSS does not appear to be of additional value. After IV tPA treatment, proximal and distal motor function in upper extremity strongly correlate over time but greater improvement in MAF is noted. Further research is needed on the role of IV tPA on minor strokes with deficits of DMF.

Achievement of Guideline-Recommended Weight Loss Among Patients With Ischemic Stroke and Obesity

Background and Purpose- The proportion of patients with acute ischemic stroke or transient ischemic attack (TIA) and obesity who successfully achieve goals for weight reduction recommended by major professional organizations is unknown. Methods- We examined the experience of participants in the placebo group of the IRIS trial (Insulin Resistance Intervention after Stroke) with a body mass index ≥30 kg/m² at entry. Patients were of age ≥40 years, with a qualifying stroke or TIA within 180 days of randomization and documented insulin resistance without diabetes mellitus. Weights at baseline and at years 1 and 2 after entry were analyzed to determine the proportion of patients achieving a 5% weight loss and achievement of body mass index <27 kg/m². Results- Of 1937 subjects assigned to placebo, 855 (44%) had obesity at entry. Median age of these 855 subjects was 60 years (interquartile range, 53-68), 41% were women, and median time from stroke/TIA to trial entry was 79 days. Among 788 subjects in the trial at 1 year, 166 (21%) had lost at least 5% of their starting weight and 12 (2%) had achieved a body mass index <27 kg/m². One hundred nine (14%) participants gained at least 5% of their baseline weight at 1 year. Among 744 subjects in the trial at 2 years, 185 (25%) had lost at least 5% of their baseline weight and 23 (3%) had achieved a body mass index <27 kg/m². One hundred forty (19%) participants gained at least 5% of their starting weight at 2 years. Conclusions- Only one quarter of obese patients with a recent ischemic stroke or TIA lost a clinically significant amount of weight after their vascular event. Many patients gained weight. Enhancing weight loss after ischemic stroke or TIA may help improve functional outcome and reduce risk for future vascular events, but clinical trials are needed to test and confirm these potential benefits.

Heart Failure After Ischemic Stroke or Transient Ischemic Attack in Insulin-Resistant Patients Without Diabetes Mellitus Treated With Pioglitazone

BACKGROUND

The IRIS trial (Insulin Resistance Intervention After Stroke) demonstrated that pioglitazone reduced the risk for both cardiovascular events and diabetes mellitus in insulin-resistant patients. However, concern remains that pioglitazone may increase the risk for heart failure (HF) in susceptible individuals.

METHODS

In IRIS, patients with insulin resistance but without diabetes mellitus were randomized to pioglitazone or placebo (1:1) within 180 days of an ischemic stroke or transient ischemic attack and followed for ≤5 years. To identify patients at higher HF risk with pioglitazone, we performed a secondary analysis of IRIS participants without HF history at entry. HF episodes were adjudicated by an external review, and treatment effects were analyzed using time-to-event methods. A baseline HF risk score was constructed from a Cox model estimated using stepwise selection. Baseline patient features (individually and summarized in risk score) and postrandomization events were examined as possible modifiers of the effect of pioglitazone. Net cardiovascular benefit was estimated for the composite of stroke, myocardial infarction, and hospitalized HF.

RESULTS

Among 3851 patients, the mean age was 63 years, and 65% were male. The 5-year HF risk did not differ by treatment (4.1% pioglitazone, 4.2% placebo). Risk for hospitalized HF was low and not significantly greater in pioglitazone compared with placebo groups (2.9% versus 2.3%, P=0.36). Older age, atrial fibrillation, hypertension, obesity, edema, high C-reactive protein, and smoking were risk factors for HF. However, the effect of pioglitazone did not differ across levels of baseline HF risk (hazard ratio [95% CI] for pioglitazone versus placebo for patients at low, moderate, and high risk: 1.03 [0.61-1.73], 1.10 [0.56-2.15], and 1.08 [0.58-2.01]; interaction P value=0.98). HF risk was increased in patients with versus those without incident myocardial infarction in both groups (pioglitazone: 31.4% versus 2.7%; placebo: 25.7% versus 2.4%; P<0.0001). Edema, dyspnea, and weight gain in the trial did not predict HF hospitalization but led to more study drug dose reduction with a lower mean dose of pioglitazone versus placebo (29±17 mg versus 33±15 mg, P<0.0001). Pioglitazone reduced the composite outcome of stroke, myocardial infarction, or hospitalized HF (hazard ratio, 0.78; P=0.007).

CONCLUSIONS

In IRIS, with surveillance and dose adjustments, pioglitazone did not increase the risk of HF and conferred net cardiovascular benefit in patients with insulin resistance and cerebrovascular disease. The risk of HF with pioglitazone was not modified by baseline HF risk. The IRIS experience may be instructive for maximizing the net benefit of this therapy.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT00091949.

Cardiac Outcomes After Ischemic Stroke or Transient Ischemic Attack: Effects of Pioglitazone in Patients With Insulin Resistance Without Diabetes Mellitus

BACKGROUND

Insulin resistance is highly prevalent among patients with atherosclerosis and is associated with an increased risk for myocardial infarction (MI) and stroke. The IRIS trial (Insulin Resistance Intervention after Stroke) demonstrated that pioglitazone decreased the composite risk for fatal or nonfatal stroke and MI in patients with insulin resistance without diabetes mellitus, after a recent ischemic stroke or transient ischemic attack. The type and severity of cardiac events in this population and the impact of pioglitazone on these events have not been described.

METHODS

We performed a secondary analysis of the effects of pioglitazone, in comparison with placebo, on acute coronary syndromes (MI and unstable angina) among IRIS participants. All potential acute coronary syndrome episodes were adjudicated in a blinded fashion by an independent clinical events committee.

RESULTS

The study cohort was composed of 3876 IRIS participants, mean age 63 years, 65% male, 89% white race, and 12% with a history of coronary artery disease. Over a median follow-up of 4.8 years, there were 225 acute coronary syndrome events, including 141 MIs and 84 episodes of unstable angina. The MIs included 28 (19%) with ST-segment elevation. The majority of MIs were type 1 (94, 65%), followed by type 2 (45, 32%). Serum troponin was 10× to 100× upper limit of normal in 49 (35%) and >100× upper limit of normal in 39 (28%). Pioglitazone reduced the risk of acute coronary syndrome (hazard ratio, 0.71; 95% confidence interval, 0.54-0.94; P=0.02). Pioglitazone also reduced the risk of type 1 MI (hazard ratio, 0.62; 95% confidence interval, 0.40-0.96; log-rank P=0.03), but not type 2 MI (hazard ratio, 1.05; 95% confidence interval, 0.58-1.91; P=0.87). Similarly, pioglitazone reduced the risk of large MIs with serum troponin >100× upper limit of normal (hazard ratio, 0.44; 95% confidence interval, 0.22-0.87; P=0.02), but not smaller MIs.

CONCLUSIONS

Among patients with insulin resistance without diabetes mellitus, pioglitazone reduced the risk for acute coronary syndromes after a recent cerebrovascular event. Pioglitazone appeared to have its most prominent effect in preventing spontaneous type 1 MIs.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov. Unique identifier: NCT00091949.

Ondansetron-related hemorrhagic posterior reversible encephalopathy syndrome (PRES) following gastric bypass

Background

Posterior reversible encephalopathy syndrome (PRES) is a clinical-radiographic syndrome formally recognized in 1996, which describes specific changes noted on neuroimaging thought to be related to impaired cerebral blood flow autoregulation and endothelial dysfunction. We report a case of PRES in the setting of increased ingestion of ondansetron; complicated by hemorrhagic transformation and refractory intracranial hypertension. We hypothesize an association of 5-HT₃ antagonism and PRES.

Findings

This is a case study report; with review of previously published literature through PubMed search. We describe the case of a 25 year old man following bariatric surgery who increased his ingestion of ondansetron, taking up to 40 tablets/day due to excessive nausea and vomiting. The patient was hospitalized for progressively more severe headache of 1 week’s duration. Computed tomography (CT) revealed bilateral cerebral edema in the parietal and occipital lobes in the setting of elevated blood pressure (BP). Three days into his admission, following improvement in his BP with oral anti-hypertensive but continued use of the ondansetron, the patient developed near complete blindness. CT head imaging revealed progression of the posterior cerebral edema and intraparenchymal hemorrhage. He was admitted to our ICU and despite supportive treatment, his neurological examination worsened while CT head imaging findings remained stable. Invasive multimodality monitoring revealed elevated intracranial pressure. The patient was aggressively treated and after a prolonged hospitalization and rehabilitation course, made a significant recovery.

Conclusion

This case highlights a very rare potential neurological complication of ondansetron, a commonly used medication. We hypothesize an underlying association between PRES and 5-HT₃ antagonism, via the latter’s potential role in endothelial dysfunction. Prompt recognition and treatment of PRES is essential, in order to prevent secondary cerebral injury and the associated potentially grave consequences.

Screening for DSM-5 Other Specified Feeding or Eating Disorder in a Weight-Loss Treatment-Seeking Obese Sample

OBJECTIVE

To evaluate the effectiveness of specific self-report questionnaires in detecting DSM-5 eating disorders identified via structured clinical interview in a weight-loss treatment-seeking obese sample, to improve eating disorder recognition in general clinical settings.

METHOD

Individuals were recruited over a 3-month period (November 2, 2011, to January 10, 2012) when initially presenting to a hospital-based weight-management center in the northeastern United States, which offers evaluation and treatment for outpatients who are overweight or obese. Participants (N = 100) completed the Structured Clinical Interview for DSM-IV eating disorder module, a DSM-5 feeding and eating disorders interview, and a battery of self-report questionnaires.

RESULTS

Self-reports and interviews agreed substantially in the identification of bulimia nervosa (DSM-IV and DSM-5: tau-b = 0.71, P < .001) and binge-eating disorder (DSM-IV and DSM-5: tau-b = 0.60, P < .001), modestly for subthreshold binge-eating disorder (tau-b = 0.44, P < .001), and poorly for other subthreshold conditions (night-eating syndrome: tau-b = -0.04, P = .72, r = 0.06 [DSM-5]).

DISCUSSION

Current self-report assessments are likely to identify full syndrome DSM-5 eating disorders in treatment-seeking obese samples, but unlikely to detect DSM-5 other specified feeding or eating disorders. We propose specific content changes that might enhance clinical utility as suggestions for future evaluation.

Do DSM-5 eating disorder criteria overpathologize normative eating patterns among individuals with obesity?

BACKGROUND

DSM-5 revisions have been criticized in the popular press for overpathologizing normative eating patterns-particularly among individuals with obesity. To evaluate the evidence for this and other DSM-5 critiques, we compared the point prevalence and interrater reliability of DSM-IV versus DSM-5 eating disorders (EDs) among adults seeking weight-loss treatment.

METHOD

Clinicians (n = 2) assigned DSM-IV and DSM-5 ED diagnoses to 100 participants via routine clinical interview. Research assessors (n = 3) independently conferred ED diagnoses via Structured Clinical Interview for DSM-IV and a DSM-5 checklist.

RESULTS

Research assessors diagnosed a similar proportion of participants with EDs under DSM-IV (29%) versus DSM-5 (32%). DSM-5 research diagnoses included binge eating disorder (9%), bulimia nervosa (2%), subthreshold binge eating disorder (5%), subthreshold bulimia nervosa (2%), purging disorder (1%), night eating syndrome (6%), and other (7%). Interrater reliability between clinicians and research assessors was "substantial" for both DSM-IV (κ = 0.64, 84% agreement) and DSM-5 (κ = 0.63, 83% agreement).

CONCLUSION

DSM-5 ED criteria can be reliably applied in an obesity treatment setting and appear to yield an overall ED point prevalence comparable to DSM-IV.

Poststroke Depression Incidence and Risk Factors

Depression is a frequent complication of stroke, but few nurse researchers have studied poststroke depression (PSD). We reviewed all published research (January 1980-March 2005) that examined the incidence of and risk factors for depression among stroke survivors during the first 3 months after stroke. Many of the 49 studies reviewed were complicated by methodological limitations, including differing definitions of stroke and depression, the use of screening instruments to diagnose depression, selection bias, assessment at different time intervals poststroke, exclusion of patients with physical or cognitive impairments, and failure to control for associated variables. The incidence of PSD ranged from 5% to 63%. A history of depression, increased stroke severity, and poststroke cognitive or physical impairment were found to be risk factors for PSD.

A web-based interactive database system for a transcranial Doppler ultrasound laboratory

BACKGROUND

Variations in transcranial Doppler (TCD) examination performance techniques and interpretive paradigms between individual laboratories are a common challenge in the practice of TCD. Demand for rapid access to patient ultrasound examination data and report for use in intensive care settings has necessitated a more flexible approach to data management. Both of these issues may benefit from a computerized approach.

METHODS

We describe the application of a World Wide Web-based database system for use in an ultrasound laboratory. Results. Databasing information while generating a TCD report is efficient. Web accessibility allows rapid and flexible communication of time-sensitive report information and interpretation for more expeditious clinical decision making.

CONCLUSIONS

Web-based applications can extend the reach and efficiency of traditionally structured medical laboratories.

Bacterial challenge stimulates innate immune responses in extra-embryonic tissues of tobacco hornworm eggs

Innate immunity protects juvenile and adult vertebrates and invertebrates against potential pathogens; however, it is unknown when developing embryos become immune competent and just how they are guarded from infection. To address these questions, we studied the effect of immune challenge on early stage eggs of the tobacco hornworm, Manduca sexta. We detected many immune-related proteins and mRNAs in naive eggs. Upon immune challenge, antimicrobial protein genes were up-regulated, and antibacterial activity increased. Antimicrobial protein mRNAs and lysozyme were present in the extra-embryonic tissues of immune-challenged eggs; in addition, melanization in response to bacteria occurred in the yolk but not embryonic tissues. We conclude that the extra-embryonic tissues of early stage M. sexta eggs are immune competent and likely protect the developing embryo from infection. We suggest that innate immune responses of extra-embryonic tissues may be a common mechanism for protecting early embryos.

Centenarian stroke treated with tissue-type plasminogen activator

BACKGROUND

Elderly patients with acute ischemic stroke often do worse than younger counterparts independent of thrombolytic therapy. Further, tissue-type plasminogen activator, (t-PA) is frequently withheld from the very old. This may be the result of comorbid conditions prohibiting its use or possibly the fear of causing more harm than good. We present a case of a 100-year-old woman who was treated with t-PA for acute ischemic stroke with rapid resolution of symptoms.

CASE DESCRIPTION

A 100-year-old woman presented to the emergency department with slurred speech, right hemiparesis and right hemisensory loss. Computed tomography revealed neither hemorrhage nor early ischemic changes. Intravenous t-PA was administered at 0.9 mg/kg 3 min prior to the 3-hour limit. She improved rapidly (NIHSS from 12 on admission to 4 at 1 month) and was discharged to the care of her family after 4 hospital days.

CONCLUSION

Intravenous thrombolysis may be beneficial in the very elderly and should be considered in any eligible elderly patients with acute ischemic stroke, with a risk/benefit analysis individualized to each case.

Multiple sclerosis presenting as ataxic hemiparesis

Multiple sclerosis (MS) can present with many clinical pictures, but only rarely as a lacunar syndrome. The following case presentation is of multiple sclerosis with initial presentation as ataxic hemiparesis (AH), indistinguishable from the vascular syndrome. This case serves to illustrate that even classic lacunar syndromes can actually be the initial manifestation of multiple sclerosis and that other etiologies besides ischemic stroke need to remain in the differential diagnosis until a definitive has been concluded.

Serine proteases as mediators of mosquito immune responses

Serine proteases regulate several invertebrate defense responses, including hemolymph coagulation, antimicrobial peptide synthesis, and melanization of pathogen surfaces. These processes require the presence of serine proteases in the hemolymph where they can rapidly activate immune pathways in response to pathogen detection. Hemolymph coagulation in the horseshoe crab is controlled by several serine proteases, including two that are pathogen recognition molecules and two in the clip domain family of serine proteases. The antimicrobial peptide synthesis and melanization pathways include clip domain proteases as well as other, uncharacterized serine proteases. We have identified five serine proteases from the hemolymph of the mosquito, Anopheles gambiae. One, Sp22D, is a large protease with potential pathogen binding domains. Sp22D is expressed in three tissues that have immune functions (midgut epithelium, fat body, and hemocytes), and its transcript abundance increases after immune challenge. Sp14A, Sp14D1, and Sp14D2 are clip domain serine proteases that are similar to enzymes with presumed roles in melanization or antimicrobial peptide synthesis. They undergo changes in transcript abundance in response to infection with bacteria or malaria parasites, and they reside in a chromosomal region that has been associated with melanization of parasites. Sp18D, also a clip domain protease, is similar to a Manduca protease with a likely role in immunity, but immune challenge does not affect its mRNA abundance.

Sp22D: a multidomain serine protease with a putative role in insect immunity

Serine proteases play critical roles in a variety of insect immune responses; however, few of the genes that code for these enzymes have been cloned. Here, we describe the molecular characterization of a serine protease gene from the mosquito Anopheles gambiae. Sp22D codes for a 1322 amino acid polypeptide with a complex domain organization. In addition to the carboxy terminal serine protease catalytic domain, Sp22D contains two putative chitin binding domains, a mucin-like domain, two low density lipoprotein receptor class A domains, and two scavenger receptor cysteine rich domains. A typical signal peptide sequence and a lack of potential transmembrane helices suggest that Sp22D is secreted. Sp22D is expressed constitutively in three immune-related cell types: adult hemocytes, fat body cells, and midgut epithelial cells. Wounding induces no changes in transcript abundance, but within 1h after injection of bacteria, Sp22D mRNA increases 1.5-fold. Based on domain organization, tissue distribution, and transcriptional up-regulation in response to immune challenge, we suggest that Sp22D has an immune function. In addition, we predict that Sp22D is secreted into the hemolymph where it may interact with pathogen surfaces and initiate an immune response.

Intravenous tissue plasminogen activator for acute ischemic stroke in patients aged 80 years and older : the tPA stroke survey experience

BACKGROUND AND PURPOSE

Intravenous tissue plasminogen activator (tPA) administered within 3 hours of symptom onset is the first available effective therapy for acute ischemic stroke (AIS). Few data exist, however, on its use in very elderly patients. We examined the characteristics, complications, and short-term outcome of AIS patients aged >/=80 years treated with tPA.

METHODS

Patients aged >/=80 years (n=30) were compared with counterparts aged <80 years (n=159) included in the tPA Stroke Survey, a US retrospective survey of 189 consecutive AIS patients treated with intravenous tPA at 13 hospitals.

RESULTS

Risk of intracerebral hemorrhage (fatal, symptomatic, and total) was 3%, 3%, and 7% in the elderly age group and 2%, 6%, and 9%, respectively, in their younger counterparts (P=NS for all comparisons). Likelihood of favorable outcome, defined as modified Rankin score 0 to 1, National Institutes of Health Stroke Scale score </=5, or marked improvement by hospital discharge, was comparable between groups (37%, 54%, and 43% versus 30%, 54%, and 43%, respectively; P=NS for all comparisons). Elderly patients were more likely to be treated by stroke specialists (87% versus 60%; P=0.005) and less likely to have an identified protocol deviation (13% versus 33%; P=0.03). Elderly patients were discharged more often to nursing care facilities (17% versus 5%; P=0.003). In logistic regression models there were no differences in odds ratio for favorable or poor outcome, other than tendency for higher in-hospital mortality in elderly patients (odds ratio, 2.8; 95% CI, 0.81 to 9.62; P=0.10).

CONCLUSIONS

Among AIS patients treated with intravenous tPA, age-related differences in characteristics and disposition were identified. No evidence for withholding tPA treatment for AIS in appropriately selected patients aged >/=80 years was identified.

Molecular characterization of five serine protease genes cloned from Anopheles gambiae hemolymph

We identified five new serine protease cDNAs from the hemolymph of the malaria vector, Anopheles gambiae. All five show sequence similarity to genes thought to be involved in vertebrate or invertebrate defense responses. Sp14A, Sp14D2 and Sp22D demonstrate changes in transcript abundance in response to bacteria injections. Sp14A and Sp14D2, as well as the previously characterized Sp14D1, are induced by infection with the malaria parasite, Plasmodium berghei. These three proteases, along with Sp18D, are related to a group of secreted proteases that have amino-terminal clip domains and trypsin-like substrate specificity. BLAST results and phylogenetic analyses group Sp14A, Sp14D1 and Sp14D2 with the Drosophila protease EASTER, and three prophenoloxidase activating enzymes from other insects. EASTER's substrate is SPAETZLE, a ligand involved in embryogenesis but also in activating anti-microbial peptide synthesis. Their similarity to EASTER and immune inducibility suggest that one of these proteases may activate a SPAETZLE-like ligand during anti-parasite responses in mosquitoes. Alternatively, as potential prophenoloxidase activators, Sp14A, Sp14D1 or Sp14D2 may play a role in melanotic encapsulation of Plasmodium.

An easter-like serine protease from Anopheles gambiae exhibits changes in transcript abundance following immune challenge

The nucleotide and deduced amino acid sequence of a serine protease (AgSp14D1) from the human malaria vector, Anopheles gambiae, is presented. The gene product is a 360 amino acid protein that contains two domains and has the highest sequence similarity to the Drosophila melanogaster serine protease easter and to prophenol oxidase activating enzyme (pPAE) from Manduca sexta. The catalytic domain is at the carboxy terminus and has the conserved serine, histidine and aspartic acid residues found in serine proteases as well as six cysteines common to invertebrate enzymes. The amino terminus contains critical cysteines that define a clip (=disulphide knot) domain which places this gene product in a subfamily of regulatory serine proteases that includes not only easter and pPAE but also the Drosophila proteins masquerade, stubble and snake as well as proclotting enzyme and factor B from the horseshoe crab. In situ hybridization to the polytene chromosomes detects a single band at 14D and Southern analysis with a probe from the 5' end of the gene confirms the single copy status of this gene. Northern analysis reveals changes in transcript abundance during development and following blood feeding. Interestingly, this analysis also shows an increase in transcript levels following wounding or injection of bacteria.

Ataxic hemiparesis: critical appraisal of a lacunar syndrome

BACKGROUND AND PURPOSE

Ataxic hemiparesis is a well-recognized lacunar syndrome involving homolateral ataxia with accompanying corticospinal tract impairment. Despite 30 years of clinical experience there continues to be some doubt as to the defining clinical characteristics, precise neuroanatomic localization of the syndrome, and etiologic mechanisms.

METHODS

We now present 45 new cases that have been analyzed for clinico-radiologic correlation and etiology. Also, all published cases from the English literature known to the authors are reviewed.

RESULTS

We found that the clinical syndrome of ataxic hemiparesis accurately predicts a small deep infarction, generally in the pons or internal capsule. Sensory loss is highly associated with a capsular localization. We found that 47% of the cases were attributed to small-vessel disease, 11% to cardioembolism, and only 7% to artery-to-artery embolism (all in the basilar artery); 1 case was attributed to thrombocytosis, 1 to multiple sclerosis, and the rest either had negative or incomplete evaluation. Approximately two thirds of the infarctions occurred in patients with neuroimaging evidence of other ischemic brain lesions.

CONCLUSIONS

Ataxic hemiparesis is a distinct clinical syndrome that accurately predicts a small deep infarction, most commonly in the pons or internal capsule. Only sensory loss accurately predicts a capsular localization. Etiology in nearly half of the cases can be attributed to small-vessel disease. Furthermore, ataxic hemiparesis appears to be a good marker for generalized asymptomatic cerebrovascular disease.

Cloning and characterization of a serine protease from the human malaria vector, Anopheles gambiae

The nucleotide and deduced amino acid sequence of a serine protease (AgSp24D) from the human malaria vector, Anopheles gambiae, is presented. The gene product is a 271 amino acid protein that contains the conserved serine, histidine and aspartic acid residues found in serine proteases, and has the highest identity to a serine protease of unknown function from Drosophila melanogaster. In situ hybridization to the polytene chromosomes detects a single band at 24D. Northern analysis reveals only low levels of transcripts in larvae and pupae, but more abundant transcription products occur in adults. Interestingly, this analysis also shows that adult males express much higher levels of AgSp24D mRNA than females. In addition, Plasmodium-refractory mosquitoes express higher levels of AgSp24D mRNA than susceptible mosquitoes although the biological significance of this remains to be examined. The thorax is the primary site for expression in the adults. The lack of a dramatic increase in AgSp24D mRNA levels following blood feeding suggests that this protease is not involved in digestive processes. Transcriptional induction does not follow cold shock, septic wounding, bacterial injection, laminarin injection or CM-Sephadex bead injection.

Mapping a quantitative trait locus involved in melanotic encapsulation of foreign bodies in the malaria vector, Anopheles gambiae

A Plasmodium-refractory strain of Anopheles gambiae melanotically encapsulates many species of Plasmodium, whereas wild-type mosquitoes are usually susceptible. This encapsulation trait can also be observed by studying the response of refractory and susceptible strains to intrathoracically injected CM-Sephadex beads. We report the results of broad-scale quantitative trait locus (QTL) mapping of the encapsulation trait using the bead model system. Interval mapping using the method of maximum likelihood identified one major QTL, Pen1. The 13.7-cM interval containing Pen1 was defined by marker AGH157 at 8E and AGH46 at 7A on 2R. Pen1 was associated with a maximum LOD score of 9.0 and accounted for 44% of the phenotypic variance in the distribution of phenotypes in the backcross. To test if this QTL is important for encapsulation of Plasmodium berghei, F2 progeny were infected with P. berghei and evaluated for degree of parasite encapsulation. For each of the two markers that define the interval containing Pen1, a significant difference of encapsulation was seen in progeny with at least one refractory allele in contrast with homozygous susceptible progeny. These results suggest that Pen1 is important for melanotic encapsulation of Plasmodium as well as beads.

A genetic study of a melanization response to Sephadex beads in Plasmodium-refractory and -susceptible strains of Anopheles gambiae

A previously selected Plasmodium-refractory strain of Anopheles gambiae melanotically encapsulates many species of Plasmodium. Genetic studies of this strain have shown that this refractory phenotype is controlled by a limited number of genes, and the existence of two such genes, Pif-B and Pif-C, has been demonstrated. Further work to determine the molecular basis for this mode of refractoriness led to the discovery that the host-parasite interaction is mimicked by the mosquito's response to carboxymethyl (CM)-Sephadex beads injected into the thorax. These small beads are melanized within 24 hr in refractory mosquitoes but are rarely melanized in susceptible ones. Because of the considerable potential in using bead melanization as a model for Plasmodium refractoriness, we performed a genetic analysis of the differential response to beads. Reciprocal crosses of susceptible (4arr) and refractory (L35) mosquitoes and an analysis of F1 phenotypes were done. The F1 progeny had a phenotype similar to that of the parental refractory mosquitoes; therefore, dominant refractory allele(s) must be present in the refractory strain. Males from the reciprocal crosses had identical phenotypes, indicating that X-linked loci did not have a visible effect on the melanizing phenotype. To further study the mode of inheritance of the melanizing trait, a backcross of F1 females to 4arr males was done. The phenotypic distribution of the backcross progeny was bimodal, and the melanization phenotypes were similar to those of the susceptible and refractory parents. These data suggest that a small number of loci are responsible for the differential response to CM-Sephadex beads, and that one chromosomal region contributes strongly to the melanizing trait. Because the 4arr strain carries mutations in the pink eye (X) and red eye (III) genes, possible linkage of the melanizing phenotype to these two genes was tested. No linkage with either marker was detected. The pattern of inheritance of the melanizing phenotype is similar to that of the refractory phenotype of Pif-B; therefore, the genetic basis of the two responses may be the same.

A shared genetic mechanism for melanotic encapsulation of CM-Sephadex beads and a malaria parasite, Plasmodium cynomolgi B, in the mosquito, Anopheles gambiae

A Plasmodium-refractory strain of Anopheles gambiae that melanizes ookinetes and intrathoracically inoculated CM-Sephadex beads was mated to a Plasmodium-susceptible strain that does not melanize the parasite or the beads. The F1 progeny were then backcrossed to the susceptible strain. Backcross progeny were given a blood meal containing infective Plasmodium cynomolgi B, and the parasites were allowed to develop for 6-7 days, at which time the infected mosquitoes were injected with CM-Sephadex beads. The next day the mosquitoes were dissected and the beads were scored for degree of melanization while the parasites were scored for degree of encapsulation. A Spearman rank order correlation test of the degree of correlation between the bead melanization phenotype and the parasite encapsulation phenotype gave a correlation coefficient of 0.74 (P < 0.01). This strong correlation between the two melanization responses suggests that the mechanisms for differential bead and parasite melanization of these two mosquito strains share at least one major gene.

Genetic analysis of embryonic cis-acting regulatory elements of the Drosophila homeotic gene sex combs reduced

The homeotic gene Sex combs reduced (Scr) of Drosophila melanogaster is expressed in the labial and prothoracic segments of the ectoderm, in parasegments two and three of the CNS, and in the visceral mesoderm of the anterior and posterior midgut. The mutationally defined function of Scr is to specify the identity of the labial and prothoracic segments and to control the development of the gastric caeca. The Scr locus occupies a chromosomal region of approximately 80 kb within the Antennapedia complex (ANT-C). To understand how Scr's spatiotemporal expression pattern is generated in the embryo, we have mapped its transcriptional regulatory elements using three approaches. First, we examined the expression pattern of Scr in embryos containing chromosomal rearrangements that remove potential Scr regulatory elements. Second, we made and analyzed a set of Scr minigene transformants. Third, we analyzed a set of Scr-lacZ enhancer tester constructs. Using more sensitive anti-SCR antisera, we discovered that Scr is expressed in tissues that were not previously thought to accumulate SCR: a stripe of ectodermal cells in the parasegment 2 region of stage 5 embryos, the embryonic salivary glands, and the dorsal ridge. Four DNA fragments that had previously been shown in an analysis of Scr-lacZ reporter constructs to contain putative Scr enhancer elements were found to have functional enhancers; similarly, another Scr fragment was found to contain a functional repressor. Our results suggest that regulation of Scr in the labial segment and the CNS requires the apparently synergistic action of multiple, widely spaced enhancer elements. Regulation in the prothorax also appears to be controlled by multiple enhancers:one complete pattern element and one subpattern element. In contrast, Scr regulation in the visceral mesoderm is controlled by an enhancer(s) located in only one DNA fragment.

A genetic analysis of deltex and its interaction with the Notch locus in Drosophila melanogaster

During Drosophila development networks of genes control the developmental pathways that specify cell fates. The Notch gene is a well characterized member of some cell fate pathways, and several other genes belonging to these same pathways have been identified because they share a neurogenic null phenotype with Notch. However, it is unlikely that the neurogenic genes represent all of the genes in these pathways. The goal of this research was to use a genetic approach to identify and characterize one of the other genes that acts with Notch to specify cell fate. Mutant alleles of genes in the same pathway should have phenotypes similar to Notch alleles and should show phenotypic interactions with Notch alleles. With this approach we identified the deltex gene as a potential cell fate gene. An extensive phenotypic characterization of loss-of-function deltex phenotypes showed abnormalities (such as thick wing veins, double bristles and extra cone cells) that suggest that deltex is involved in cell fate decision processes. Phenotypic interactions between deltex and Notch as seen in double mutants showed that Notch and deltex do not code for duplicate functions and that the two genes function together in many different developing tissues. The results of these investigations lead to the conclusion that the deltex gene functions with the Notch gene in one or more developmental pathways to specify cell fate.