Atherosclerosis and depression: is carotid intima-media thicker in patients with depression compared to matched control individuals? A systematic review and meta-analysis

OBJECTIVE

To investigate if there is an association between atherosclerosis and depression by using as imaging biomarker the carotid intima media thickness (cIMT), a surrogate marker for atherosclerosis.

METHODS

PubMed/Medline, Embase and Cochrane databases were comprehensively searched to identify studies investigating the association between cIMT and depression. The results were pooled using a random-effects statistical model, appropriate for the expected high heterogeneity. Sensitivity and subgroup analyses were conducted where data was available.

RESULTS

Overall, 22 and 13 studies met inclusion criteria for the qualitative and the quantitative synthesis, respectively, with a total of 4466 patients and 21,635 control participants. Results showed that cIMT is significantly higher in the depression, compared to the control groups with an overall mean difference of 0.07 mm (95% CI 0.04-0.10, p < 0.01). Subgroup analysis showed that diabetes could present as a confounding factor in patients with depression and an increased cIMT.

CONCLUSIONS

This study confirms a significantly increased cIMT in patients with depression, compared with controls and suggests a possible bidirectional link between atherosclerosis and depression. An early screening of cardiovascular disease in individuals suffering with depression should be considered.

Rapid point-of-care detection of SARS-CoV-2 infection in exhaled breath using ion mobility spectrometry: a pilot study

BACKGROUND

An effective testing strategy is essential for pandemic control of the novel Coronavirus disease 2019 (COVID-19) caused by infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Breath gas analysis can expand the available toolbox for diagnostic tests by using a rapid, cost-beneficial, high-throughput point-of-care test. We conducted a bi-center clinical pilot study in Germany to evaluate breath gas analysis using multi-capillary column ion mobility spectrometry (MCC-IMS) to detect SARS-CoV-2 infection.

METHODS

Between September 23, 2020, and June 11, 2021, breath gas measurements were performed on 380 patients (SARS-CoV-2 real-time polymerase chain reaction (PCR) positive: 186; PCR negative: 194) presenting to the emergency department (ED) with respiratory symptoms.

RESULTS

Breath gas analysis using MCC-IMS identified 110 peaks; 54 showed statistically significant differences in peak intensity between the SARS-CoV-2 PCR-negative and PCR-positive groups. A decision tree analysis classification resulted in a sensitivity of 83% and specificity of 86%, but limited robustness to dataset changes. Modest values for the sensitivity (74%) and specificity (52%) were obtained using linear discriminant analysis. A systematic search for peaks led to a sensitivity of 77% and specificity of 67%; however, validation by transferability to other data is questionable.

CONCLUSIONS

Despite identifying several peaks by MCC-IMS with significant differences in peak intensity between PCR-negative and PCR-positive samples, finding a classification system that allows reliable differentiation between the two groups proved to be difficult. However, with some modifications to the setup, breath gas analysis using MCC-IMS may be a useful diagnostic toolbox for SARS-CoV-2 infection.

TRIAL REGISTRATION

This study was registered at ClinicalTrials.gov on September 21, 2020 (NCT04556318; Study-ID: HC-N-H-2004).

A Multicenter Longitudinal MRI Study Assessing LeMan-PV Software Accuracy in the Detection of White Matter Lesions in Multiple Sclerosis Patients

BACKGROUND

Detecting new and enlarged lesions in multiple sclerosis (MS) patients is needed to determine their disease activity. LeMan-PV is a software embedded in the scanner reconstruction system of one vendor, which automatically assesses new and enlarged white matter lesions (NELs) in the follow-up of MS patients; however, multicenter validation studies are lacking.

PURPOSE

To assess the accuracy of LeMan-PV for the longitudinal detection NEL white-matter MS lesions in a multicenter clinical setting.

STUDY TYPE

Retrospective, longitudinal.

SUBJECTS

A total of 206 patients with a definitive MS diagnosis and at least two follow-up MRI studies from five centers participating in the Swiss Multiple Sclerosis Cohort study. Mean age at first follow-up = 45.2 years (range: 36.9-52.8 years); 70 males.

FIELD STRENGTH/SEQUENCE

Fluid attenuated inversion recovery (FLAIR) and T1-weighted magnetization prepared rapid gradient echo (T1-MPRAGE) sequences at 1.5 T and 3 T.

ASSESSMENT

The study included 313 MRI pairs of datasets. Data were analyzed with LeMan-PV and compared with a manual "reference standard" provided by a neuroradiologist. A second rater (neurologist) performed the same analysis in a subset of MRI pairs to evaluate the rating-accuracy. The Sensitivity (Se), Specificity (Sp), Accuracy (Acc), F1-score, lesion-wise False-Positive-Rate (aFPR), and other measures were used to assess LeMan-PV performance for the detection of NEL at 1.5 T and 3 T. The performance was also evaluated in the subgroup of 123 MRI pairs at 3 T.

STATISTICAL TESTS

Intraclass correlation coefficient (ICC) and Cohen's kappa (CK) were used to evaluate the agreement between readers.

RESULTS

The interreader agreement was high for detecting new lesions (ICC = 0.97, Pvalue < 10-20 , CK = 0.82, P value = 0) and good (ICC = 0.75, P value < 10-12 , CK = 0.68, P value = 0) for detecting enlarged lesions. Across all centers, scanner field strengths (1.5 T, 3 T), and for NEL, LeMan-PV achieved: Acc = 61%, Se = 65%, Sp = 60%, F1-score = 0.44, aFPR = 1.31. When both follow-ups were acquired at 3 T, LeMan-PV accuracy was higher (Acc = 66%, Se = 66%, Sp = 66%, F1-score = 0.28, aFPR = 3.03).

DATA CONCLUSION

In this multicenter study using clinical data settings acquired at 1.5 T and 3 T, and variations in MRI protocols, LeMan-PV showed similar sensitivity in detecting NEL with respect to other recent 3 T multicentric studies based on neural networks. While LeMan-PV performance is not optimal, its main advantage is that it provides automated clinical decision support integrated into the radiological-routine flow.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 2.

Does Functional Imaging Play a Role in Pre-Operative Diagnosis of Brain Tumours?

Although there is a large variability in the neural organization of language function between individuals, there is an ongoing debate about functional imaging as a standard procedure in the preoperative setting of brain tumors. Brain mapping of the language centers differs from individual to individual in multilingual patients and changes in its architecture may occur as a result of neuroplasticity induced by a mass lesion. This article discusses the role of functional imaging in the preoperative setting.

Global Cortical Atrophy Is Associated with an Unfavorable Outcome in Stroke Patients on Oral Anticoagulation

INTRODUCTION

Measures of cerebral small vessel disease (cSVD), such as white matter hyperintensities (WMH) and cerebral microbleeds (CMB), are associated with an unfavorable clinical course in stroke patients on oral anticoagulation (OAC) for atrial fibrillation (AF). Here, we investigated whether similar findings can be observed for global cortical atrophy (GCA).

METHODS

Registry-based prospective observational study of 320 patients treated with OAC following AF stroke. Patients underwent magnetic resonance imaging (MRI) allowing assessment of GCA. Using the simplified visual Pasquier scale, the severity of GCA was categorized as follows: 0: no atrophy, 1: mild atrophy; 2: moderate atrophy, and 3: severe atrophy. Using adjusted logistic and Cox regression analysis, we investigated the association of GCA using a composite outcome measure, comprising: (i) recurrent acute ischemic stroke (IS); (ii) intracranial hemorrhage (ICH); and (iii) death.

RESULTS

In our time to event analysis after adjusting for potential confounders (i.e., WMH, CMB, age, sex, diabetes, arterial hypertension, coronary heart disease, hyperlipidemia, and antiplatelet use), GCA was associated with an increased risk for the composite outcome in all three degrees of atrophy (grade 1: aHR 3.95, 95% CI 1.34-11.63, p = 0.013; grade 2: aHR 3.89, 95% CI 1.23-12.30, p = 0.021; grade 3: aHR 4.16, 95% CI 1.17-14.84, p = 0.028).

CONCLUSION

GCA was associated with our composite outcome also after adjusting for other cSVD markers (i.e., CMB, WMH) and age, indicating that GCA may potentially serve as a prognostic marker for stroke patients with atrial fibrillation on oral anticoagulation.

Endoscopic and Computed Tomography Evaluation of Posterior Glottic Closure During Phonation

OBJECTIVES/HYPOTHESIS

The anatomy of the posterior glottis, specifically the states of the posterior glottis during phonation, has not been thoroughly explored in laryngology. Conventional wisdom about the posterior glottis indicates that it tends to be completely closed in men but may be open in women. Furthermore, professional singers are expected to have a completely closed posterior glottis. The aim of this study was to investigate whether these generalizations are true by comparing rigid videolaryngostroboscopy results with high-resolution computed tomography (HRCT) and three-dimensional (3D) reconstruction findings.

STUDY DESIGN

Prospective study.

METHODS

Of the 90 volunteers (58 women, 32 men) examined, 48 were female professional singers, 10 were female nonsingers, 22 were male professional singers, and 10 were male nonsingers. Rigid videolaryngostroboscopy as well as HRCT scans were performed during singing at the average singing fundamental frequency. HRCT images of the larynx and air-column were 3D visualized using the software MIMICS®. The states of the posterior glottis were assessed in both examinations and compared among participants.

RESULTS

The sensitivity of endoscopy was 67.5%. Complete closure of the posterior glottis was observed in 62.5% men and 52% women (P = .33). Complete closure of the posterior glottis was observed in 35% nonsingers and 61% professional singers (P = .036).

CONCLUSIONS

The closure of the posterior glottis seen on videolaryngostroboscopy does not always correlate with actual closure. There seems to be no link between sex and complete closure of the glottis. However, there is strong evidence that posterior glottis closure can be influenced, to some degree, by vocal training.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

Intrathecal Immunoglobulin M Synthesis is an Independent Biomarker for Higher Disease Activity and Severity in Multiple Sclerosis

OBJECTIVE

We aimed to determine in relapsing multiple sclerosis (MS) whether intrathecal synthesis of immunoglobulin (Ig) M and IgG is associated with outcomes reflecting inflammatory activity and chronic worsening.

METHODS

We compared cerebrospinal fluid analysis, clinical and magnetic resonance imaging data, and serum neurofilament light chain (sNfL) levels at baseline and follow-up in 530 patients with relapsing MS. Patients were categorized by the presence of oligoclonal IgG bands (OCGB) and intrathecal synthesis of IgG and IgM (intrathecal fraction [IF]: IgG_IF and IgM_IF ). Relationships with the time to first relapse, sNfL concentrations, T2-weighted (T2w) lesions, MS Severity Score (MSSS), and time to initiation of high-efficacy therapy were analyzed in covariate-adjusted statistical models.

RESULTS

By categorical analysis, in patients with IgM_IF the median time to first relapse was 28 months shorter and MSSS on average higher by 1.11 steps compared with patients without intrathecal immunoglobulin synthesis. Moreover, patients with IgM_IF had higher sNfL concentrations, more new/enlarging T2w lesions, and higher total T2w lesion counts (all p ≤ 0.01). These associations were absent or equally smaller in patients who were positive for only OCGB or OCGB/IgG_IF . Furthermore, quantitative analyses revealed that in patients with IgM_IF  ≥ median, the time to first relapse and to initiation of high-efficacy therapy was shorter by 32 and by 203 months, respectively (both p < 0.01), in comparison to patients with IgM_IF  < median. Dose-dependent associations were also found for IgM_IF but not for IgG_IF with magnetic resonance imaging-defined disease activity and sNfL.

INTERPRETATION

This large study supports the value of intrathecal IgM synthesis as an independent biomarker of disease activity and severity in relapsing MS. ANN NEUROL 2021.

Small vessel disease is associated with an unfavourable outcome in stroke patients on oral anticoagulation

Introduction

Cerebral small vessel disease is an important cause for both ischaemic stroke and intracranial haemorrhage. To date, knowledge on the impact of small vessel disease on the clinical course in stroke patients treated with oral anticoagulation for atrial fibrillation is limited.

Patients and Methods

Registry-based prospective observational study of 320 patients (aged 78.2 ± 9.2 years) treated with anticoagulation following atrial fibrillation stroke. Patients underwent standardised magnetic-resonance-imaging assessing measures of small vessel disease, including cerebral microbleeds and white matter hyperintensities. Median follow-up was 754 (interquartile range = [708-828]) days. Using adjusted logistic and Cox regression, we assessed the association of imaging measures with clinical outcome including recurrent ischaemic stroke, intracranial haemorrhage and death and assessed disability (modified Rankin Scale).

Results

Overall, recurrent ischaemic stroke was more common than intracranial haemorrhage (22 versus 8, respectively). Cerebral microbleeds were related to an increased risk of the composite endpoint (ischaemic stroke, intracranial haemorrhage, death: odds ratio (OR) 2.05, 95% confidence interval (CI) 1.27-3.31; P = 0.003), as were white matter hyperintensities (OR 2.00, 95%CI 1.23-3.27, P = 0.005). This was also true in time-to-event analysis (cerebral microbleeds: HR 2.31, 95%CI 1.39-3.52; P < 0.001; white matter hyperintensities: HR 1.99, 95%CI 1.20-3.17; P = 0.007). Both measures were associated with an increased risk for recurrent ischaemic stroke (cerebral microbleeds: HR 4.42, 95%CI 1.07-18.20; P = 0.04; white matter hyperintensities: HR 5.27, 95%CI 1.08-25.79, P = 0.04) and intracranial haemorrhage (cerebral microbleeds: HR 2.43, 95%CI 1.04-5.69; P = 0.04; white matter hyperintensities: HR 2.57, 95%CI 1.11-5.98, P = 0.03). Furthermore, confluent white matter hyperintensities were associated with increased disability (OR 4.03; 95%CI 2.16-7.52; P < 0.001) and mortality (HR 1.81, 95%CI 1.04-3.14, P = 0.04).

Discussion and conclusion

In atrial fibrillation stroke patients treated with oral anticoagulation, small vessel disease is associated with an unfavourable outcome. The presence of microbleeds indicated a risk higher for recurrent ischaemic stroke than for intracranial haemorrhage.

Systematic Radiation Dose Reduction in Cervical Spine CT of Human Cadaveric Specimens: How Low Can We Go?

BACKGROUND AND PURPOSE

While the use of cervical spine CT in trauma settings has increased, the balance between image quality and dose reduction remains a concern. The purpose of our study was to compare the image quality of CT of the cervical spine of cadaveric specimens at different radiation dose levels.

MATERIALS AND METHODS

The cervical spine of 4 human cadavers (mean body mass index; 30.5 ± 5.2 kg/m²; range, 24-36 kg/m²) was examined using different reference tube current-time products (45, 75, 105, 135, 150, 165, 195, 275, 355 mAs) and a tube voltage of 120 kV(peak). Data were reconstructed with filtered back-projection and iterative reconstruction. Qualitative image noise and morphologic characteristics of bony structures were quantified on a Likert scale. Quantitative image noise was measured. Statistics included analysis of variance and the Tukey test.

RESULTS

Compared with filtered back-projection, iterative reconstruction provided significantly lower qualitative (mean noise score: iterative reconstruction = 2.10/filtered back-projection = 2.18; P = .003) and quantitative (mean SD of Hounsfield units in air: iterative reconstruction = 30.2/filtered back-projection = 51.8; P < .001) image noise. Image noise increased as the radiation dose decreased. Qualitative image noise at levels C1-4 was rated as either "no noise" or as "acceptable noise." Any shoulder position was at level C5 and caused more artifacts at lower levels. When we analyzed all spinal levels, scores for morphologic characteristics revealed no significant differences between 105 and 355 mAs (P = .555), but they were worse in scans at 75 mAs (P = .025).

CONCLUSIONS

Clinically acceptable image quality of cervical spine CTs for evaluation of bony structures of cadaveric specimens with different body habitus can be achieved with a reference mAs of 105 at 120 kVp with iterative reconstruction. Pull-down of shoulders during acquisition could improve image quality but may not be feasible in trauma patients with unknown injuries.

[Osler's disease]

Osler's disease, also known as hereditary hemorrhagic telangiectasia (HHT) and Osler-Weber-Rendu syndrome, is an autosomal dominant disorder leading to abnormal blood vessel formation in the skin, mucous membranes and often in organs, such as the lungs, liver and brain (arteriovenous malformations AVM). Various types are known. Patients may present with epistaxis. Teleangiectasia can be identified by visual inspection during physical examination of the skin or oral cavity or by endoscopy. Diagnosis is made after clinical examination and genetic testing based on the Curacao criteria. Modern imaging modalities, such as computed tomography (CT) or magnetic resonance imaging (MRI) have become more important as they can depict the AVMs. Pulmonary AVMs can be depicted in CT imaging even without the use of a contrast agent while other locations including the central nervous system (CNS) usually require administration of contrast agents. Knowledge of possible clinical manifestations in various organs, possible complications and typical radiological presentation is mandatory to enable adequate therapy of these patients. Interventional procedures are becoming increasingly more important in the treatment of HHT patients.

Defeating cancer with antidepressants

Prostaglandins are ephemeral, infinitesimal signallers self-regulating every cell in the body, including those sub-serving mood and immunity. At first, they were perceived as a master switch, but now are believed to regulate every component of cellular micro-anatomy and physiology, including those of the organelles, cytoskeleton, proteins, enzymes, nucleic acids and mitochondria. Prostaglandins are responsible, paradoxically, for cell function and dysfunction. Excessive prostaglandin synthesis depresses immune function and may induce cancer. An ideal anti-cancer agent would inhibit prostaglandins in such a manner as to shut down the pathogenesis of cancer. In this paper, I will show that antidepressants have such properties.

Antidepressants, eicosanoids and the prevention and treatment of cancer. A review

Among the mechanisms of carcinogenesis are oncogene synthesis and expression, upregulation of cyclooxygenase, accelerated cell replication, failed apoptosis, viral activation, disruption of signaling pathways, autoimmunity, immunosuppression, angiogenesis and metastasis. All fall within the orbit of eicosanoids and the enzymes that synthesize them. Antidepressants may be of benefit in the prevention and treatment of cancer, as they inhibit the synthesis, antagonize the actions and accelerate the degradation of such eicosanoids as prostaglandins and thromboxanes.

Increased blood flow after catheterization and drainage in the chronically obstructed rabbit urinary bladder

OBJECTIVES

To determine the effect of drainage on rabbit bladder blood flow after 4 weeks of partial outlet obstruction. Previous studies have shown that catheterization and drainage of the urinary bladder in control rabbits resulted in a significant nitric oxide-induced increase of blood flow to the bladder. It was also shown that 4 weeks' partial outlet obstruction caused a significant decrease in blood flow to the bladder.

METHODS

Male New Zealand White rabbits underwent partial outlet obstruction by standard methods. After 4 weeks, the blood flow to the bladder muscle and mucosa was determined by a microsphere technique. Within 1 to 2 minutes after transurethral catheterization and complete drainage of the bladder, the blood flow was again determined. Unobstructed animals served as controls. Four other control animals underwent a repetitive blood flow study during 10 minutes to determine the time frame of blood flow changes after drainage. Blood flow was also measured in 2 control rabbits after transurethral catheterization without drainage and in 2 control rabbits after drainage by suprapubic puncture. To exclude the possibility that increased intravesical pressure alters the blood flow measurements, the relationship between the intravesical volume and the bladder pressure was examined in the obstructed rabbits.

RESULTS

After drainage of the bladder, the blood flow to the bladder muscle increased 4.5-fold in the decompensated obstructed group (bladder weights greater than 15 g) and 2.5-fold in the compensated animals (bladder weights less than 5 g) and control animals. Blood flow to the mucosa followed the same pattern but without reaching significance. Blood flow returned to near baseline values within 5 minutes. Catheterization without drainage did not alter the blood flow. In contrast, drainage by puncture increased the blood flow significantly. Higher intravesical volumes increased the intravesical pressure slightly, but after opening the abdominal fascia, the intravesical pressure did not change with increasing volumes.

CONCLUSIONS

Although the previously shown decreased blood flow to the bladder smooth muscle may be an etiologic factor in bladder contractile dysfunction secondary to partial outlet obstruction, the bladder does have the ability to increase the blood flow after drainage. This ability could be a compensatory and possibly protective mechanism after outlet obstruction.

Eicosanoids: the molecules of evolution

The molecules of evolution constitute a response system linking the environment to the internal machinery of cells and are key factors in evolutionary disorders. They orchestrate such mechanisms of evolution as replication and reproduction, variation, inheritance, natural selection, heterochrony, neoteny, aging, recapitulation, metamorphosis, homology, paradox, and extinction. Eicosanoids fulfill these criteria.

The effect of urine volume and nitric oxide on basal bladder blood flow: response to catheterization and drainage

Preliminary studies demonstrated that catheterization and drainage of the urinary bladder resulted in a significant increase in blood flow to the bladder. The objectives of this study were to determine 1) the relationship between urine volume and basal blood flow to the bladder smooth muscle and mucosa, 2) the effect of acute catheterization and drainage on bladder mucosal and smooth muscle blood flow, and 3) whether nitric oxide was involved in regulation of basal blood flow or the increase in blood flow observed after catheterization and bladder drainage. Twenty-four rabbits were separated into two groups: group 1 (14 rabbits) and group 2 (10 rabbits) treated with L-NAME (NOS inhibitor) 30 minutes before blood flow measurement. Blood flow was measured in all animals using a fluorescent microsphere technique before and immediately after catheterization and drainage of the bladder. The results demonstrated that 1) blood flow to the muscle and mucosa were independent of urine volume at the time of catheterization and drainage; 2) catheterization and drainage significantly increased blood flow to both the bladder smooth muscle and bladder mucosa, but not to the kidney; 3) L-NAME significantly reduced basal blood flow to the kidney, but not to the bladder smooth muscle or mucosa; and 4) L-NAME completely prevented the catheterization- and drainage-induced increases in blood flow to the bladder body mucosa and muscle. This study demonstrates that basal blood flow to the bladder smooth muscle and mucosa during filling is independent of NO control; although bladder blood flow may be increased significantly by NO synthesis and release during bladder emptying, and thus may be an important regulator of blood flow during and immediately following micturition.

Effect of chronic bladder outlet obstruction on blood flow of the rabbit bladder

PURPOSE

Previous studies have shown that the initial reaction of the rabbit bladder to partial bladder outlet obstruction is increased blood flow at day 1 and a return to baseline blood flow at 1 week. Mucosal and muscle blood flow followed this pattern but mucosal blood flow was always 4 to 5-fold greater. In this study we examined the effect of 4 weeks of outlet obstruction on bladder blood flow and correlated it with the severity of bladder contractile dysfunction.

MATERIALS AND METHODS

A total of 14 male New Zealand White rabbits underwent partial outlet obstruction creation by standard methods. After 4 weeks the rabbits were anesthetized, and blood flow to the muscle and mucosa was determined by standard fluorescent microsphere technique. A section of each detrusor was used for in vitro contractility studies. Contractile responses to field stimulation, carbachol and potassium chloride were determined. A section of each detrusor tissue was fixed in formalin and used to determine the smooth muscle volume fraction.

RESULTS

Four weeks of partial bladder outlet obstruction caused a significant and variable increase in bladder weight and a decrease in blood flow to bladder muscle without changes in the blood flow to mucosa. There was a clear correlation between the severity of contractile dysfunction, bladder weight and the magnitude of the decrease in blood flow in muscle. The smooth muscle volume fraction remained stable at approximately 40%.

CONCLUSIONS

Bladder decompensation was associated with decreased blood flow to bladder smooth muscle. Because compensated obstructed bladders with relatively normal contractile function are also hypertrophied but have normal blood flow, decreased blood flow in decompensated bladders is not simply a response to bladder hypertrophy. From this study we hypothesize that decreased blood flow to bladder smooth muscle is an etiological factor in bladder contractile dysfunction (bladder decompensation) secondary to partial outlet obstruction.

Vascular response of the rabbit bladder to short term partial outlet obstruction

Partial bladder outlet obstruction of the rabbit bladder results in a rapid increase in mass characterized by remodeling of the bladder wall. In this study we investigated the effect of partial outlet obstruction on microvessel density and distribution in the bladder wall immunohistochemically using CD31 as a marker for vascular endothelium, and on blood flow using a fluorescent microsphere technique. Transverse sections of bladder wall were examined after 0 (unobstructed), 1, 3, 5, 7, and 14 days of obstruction. The microvasculature of obstructed rabbit bladder mucosa and detrusor smooth muscle apparently increased relative to augmentation of these compartments, while new vessels appeared in the thickening serosa. These vascular changes correlated with results showing that, at 1 week after obstruction, blood flow (ml/min/g tissue) to the mucosa and detrusor was unchanged. Thickening of the serosa, apparent after 1 day of obstruction, began before its vascularization. Then, 1 week post-obstruction, there was significant microvessel formation in the transition region between the detrusor smooth muscle and the increasing serosa; after 2 weeks, the entire serosa was vascularized. The vascularization of the muscle-serosal transition region and then the remaining serosa apparently precedes fibroblast differentiation, providing blood supply and thus metabolic support for this process. All obstructed rabbit bladders in this study were in a state of compensated function based on their weights. Our working hypothesis is that blood flow per unit tissue mass is normal in compensated obstructed bladders, thus allowing for normal contractile function and cellular metabolism. The results of this study indicate the presence of an augmented microvasculature in compensated obstructed rabbit bladders that provides adequate blood perfusion for normal function.

Lithium and immune function

Lithium has potent antiviral and immunostimulating properties which are probably consequences of its actions on prostaglandin synthesis. Although lithium has considerable potential in the prophylaxis of some viral illnesses and other manifestations of defective immune function, it is, paradoxically, capable of activating autoimmune mechanisms in predisposed patients.

The role of prostaglandin E2 in seminal immunosuppression

Seminal plasma, which has high antigenic potential and the capacity to induce immunosuppression, has been incriminated as a possible factor in the acquired immunodeficiency syndrome (AIDS). Seminal plasma contains high concentrations of prostaglandins, which are capable of inducing immunosuppression. As prostaglandin E2 is noted for its immunosuppressive actions, we designed this study to determine whether this prostaglandin is responsible for seminal immunosuppression. Diluted and undiluted samples of semen from 5 heterosexual donors induced a significant suppression of phytohaemagglutinin-stimulated thymidine incorporation into lymphocytes. However, when the prostaglandin E2 levels of the semen samples were extrapolated to a standard prostaglandin E2 dose-response curve, the estimated values did not agree with the prostaglandin E2 levels. We conclude that prostaglandin E2 may contribute to seminal immunosuppression, but is not solely responsible for it.

Antidepressant tachyphylaxis

We report eleven patients in whom tachyphylaxis to antidepressants, lithium or ECT occurred. These cases are a small sample of patients we have encountered in whom an initial good response to mood regulating drugs was not sustained. We suspect that systematic studies would reveal that tachyphylaxis is a common phenomenon with antidepressant therapies.

Elevated levels of prostaglandin E2 and thromboxane B2 in depression

Plasma prostaglandin E2 (PGE2) and thromboxane B2 (TXB2) levels were measured in 30 depressed outpatients. Plasma PGE2 was increased in all but one of these patients (p less than 0.001) and all had increased levels of TXB2 (p less than 0.001). Since monamine oxidase inhibitors inhibit brain prostaglandin synthesis, and tricyclic antidepressants may antagonize prostaglandin actions, these observations suggest new approaches to depression research.

Remission of rheumatoid arthritis and other disorders of immunity in patients taking monoamine oxidase inhibitors

Elevated levels of prostaglandin E2 (PGE2) play an important role in rheumatoid arthritis and other disorders of immunity. By inhibiting the release of arachidonic acid from cells, monoamine oxidase inhibitors (MAOI's) inhibit PGE2 synthesis. MAOI's appear to be capable of remitting the symptoms of rheumatoid arthritis and may have the potential to arrest it. MAOI's also appear to be effective in other disturbances of immunity in which excessive synthesis of PGE2 plays a role.

Lithium treatment of hypothermia caused by electric shock

Prostaglandins have hyperthermic as well as hypothermic effects, and lithium, which inhibits the conversion of dihomogammalinolenic acid to PGE1, can produce hyperthermia. Electroconvulsive shock raises prostaglandin F in rat cerebral cortex and in the case presented here lithium normalized temperature in a patient who became hypothermic after she accidentally received an electric shock.

Linoleic acid in the treatment of lithium toxicity and familial tremor

Lithium inhibits the synthesis of prostaglandin (PG) EI by blocking the mobilisation of dihomogammalinolenic acid (DGLA). Toxicity due to lithium might re related to reduced PGEI formation. In five patients who developed toxic effects on low doses of lithium, linoleic acid in the forms of the safflower oil was given in an attempt to raise levels of the linoleic acid metabolite, DGLA. In al five patients the safflower oil was effective in remitting the symptoms of neurotoxicity. Safflower oil was also effective in a patient with familial tremor.

Lithium treatment of chronic cluster headaches

On the basis of reports of reduced MAO activity in migraine and cluster headaches and on a report that lithium carbonate activates MAO, the authors administered lithium carbonate to two patients whose cluster headaches had brought them to the point of contemplating suicide. Both patients responded quite dramatically. Case 1 has now been virtually free of headaches for over two years and Case 2 has been in remission for over twelve months.

Brief communication treatment of delusional depression with tranylcypromine

Patients with depressions accompanied by delusional thinking are reported to respond poorly to tricyclic antidepressants. We present four cases of delusional depression successfully treated with tranylcypromine. Three patients had previously been treated unsuccessfully with adequate trials of tricyclic antidepressants and one had been treated with a tricyclic-phenothiazine combination with a poor response. These four patients experienced a dramatic reduction in depression and delusional thinking when treated with tranylcypromine. On the basis of these cases, tranylcypromine appears to be an effective treatment for some patients with delusional depressions.