A randomized, open-label, multicenter study of switching to brolucizumab with or without a loading dose for patients with suboptimal anatomically controlled neovascular age-related macular degeneration-the FALCON study

Background

Treatment initiation with brolucizumab, a new potent anti-vascular endothelial growth factor (VEGF) agent, is typically performed with three monthly injections (loading dose) and has been well studied in treatment-naïve patients. However, no clinical data are available yet on whether or not anti-VEGF pretreated patients also benefit from a loading dose. In the clinical setting, different heterogeneous treatment patterns are used as no clinical trial has addressed this so far in a head-to-head comparison. Therefore, the FALCON study is investigating whether patients with unsatisfactory response to previous anti-VEGF treatments benefit from a loading dose at the switch to brolucizumab treatment.

Methods

FALCON is a 52-week, two-arm, randomized, open-label, multicenter, multinational study in patients with residually active neovascular age-related macular degeneration (nAMD) who will be randomized 1:1 and started with brolucizumab 6 mg loading (three monthly loading doses) or brolucizumab 6 mg non-loading (one initial injection) and consecutive treatment every 12 weeks, respectively. The primary objective is to demonstrate non-inferiority of the non-loading vs. loading arm in mean change of best-corrected visual acuity (BCVA) from baseline to the mean value at week 40 to week 52. Secondary objectives include the assessment of anatomical outcomes, treatment intervals, safety and tolerability.

Results

FALCON will be the first study to assess treatment initiation with an anti-VEGF agent in a switch situation with or without loading dose in patients with nAMD.

Conclusions

The results will support the optimization of treatment of patients with previous unsatisfactory anti-VEGF response. Therefore, we expect to see an impact on current clinical practice which has been established for more than a decade.

Trial registration

Clinicaltrials.gov: NCT04679935, date of registration—22-Dec 2020; EUDRACT number: 2019–004763-53, date of registration—03 Dec 2019.

A community-based transcriptomics classification and nomenclature of neocortical cell types

To understand the function of cortical circuits, it is necessary to catalog their cellular diversity. Past attempts to do so using anatomical, physiological or molecular features of cortical cells have not resulted in a unified taxonomy of neuronal or glial cell types, partly due to limited data. Single-cell transcriptomics is enabling, for the first time, systematic high-throughput measurements of cortical cells and generation of datasets that hold the promise of being complete, accurate and permanent. Statistical analyses of these data reveal clusters that often correspond to cell types previously defined by morphological or physiological criteria and that appear conserved across cortical areas and species. To capitalize on these new methods, we propose the adoption of a transcriptome-based taxonomy of cell types for mammalian neocortex. This classification should be hierarchical and use a standardized nomenclature. It should be based on a probabilistic definition of a cell type and incorporate data from different approaches, developmental stages and species. A community-based classification and data aggregation model, such as a knowledge graph, could provide a common foundation for the study of cortical circuits. This community-based classification, nomenclature and data aggregation could serve as an example for cell type atlases in other parts of the body.

Systems Neuroscience of Natural Behaviors in Rodents

Animals evolved in complex environments, producing a wide range of behaviors, including navigation, foraging, prey capture, and conspecific interactions, which vary over timescales ranging from milliseconds to days. Historically, these behaviors have been the focus of study for ecology and ethology, while systems neuroscience has largely focused on short timescale behaviors that can be repeated thousands of times and occur in highly artificial environments. Thanks to recent advances in machine learning, miniaturization, and computation, it is newly possible to study freely moving animals in more natural conditions while applying systems techniques: performing temporally specific perturbations, modeling behavioral strategies, and recording from large numbers of neurons while animals are freely moving. The authors of this review are a group of scientists with deep appreciation for the common aims of systems neuroscience, ecology, and ethology. We believe it is an extremely exciting time to be a neuroscientist, as we have an opportunity to grow as a field, to embrace interdisciplinary, open, collaborative research to provide new insights and allow researchers to link knowledge across disciplines, species, and scales. Here we discuss the origins of ethology, ecology, and systems neuroscience in the context of our own work and highlight how combining approaches across these fields has provided fresh insights into our research. We hope this review facilitates some of these interactions and alliances and helps us all do even better science, together.

Simultaneous removal of rotavirus and adenovirus from artificial ground water using hydrochar derived from swine feces

Hydrothermal carbonization technology can convert fecal waste into a valuable carbonaceous product referred to as hydrochar. We investigated the potential of fecal waste-derived hydrochar as an adsorbent for virus removal in water treatment. Swine feces was hydrothermally treated under two conditions: at 180 °C for 2 h and 230 °C for 7 h. The resulting solid products (hydrochar) were evaluated as virus adsorbents in water treatment. Simultaneous removal of pathogenic rotavirus (RV) and human adenovirus (HAdV) was investigated using a sand column set-up of 10 cm bed height with and without hydrochar supplement (1.5%, w/w). The removal efficiency of both viruses in a hydrochar-amended column was >3 log (complete removal). The amount of virus released in deionized water when flushed into the virus-retaining columns indicated that the secondary energy minimum played a more important role in RV retention than that of HAdV. Zeta-potential and hydrophobicity measurements on hydrochar materials indicated that the improved virus removal performance of hydrochar-amended columns was induced by the provision of extra hydrophobic surfaces. This study provides evidence that fecal waste-derived hydrochar can be used as a competent virus adsorbent.

Induction of apoptosis in human cancer cells by targeting mitochondria with gold nanoparticles

A major challenge in designing cancer therapies is the induction of cancer cell apoptosis, although activation of intrinsic apoptotic pathways by targeting gold nanoparticles to mitochondria is promising. We report an in vitro procedure targeting mitochondria with conjugated gold nanoparticles and investigating effects on apoptosis induction in the human breast cancer cell line Jimt-1. Gold nanoparticles were conjugated to a variant of turbo green fluorescent protein (mitoTGFP) harbouring an amino-terminal mitochondrial localization signal. Au nanoparticle conjugates were further complexed with cationic maltotriose-modified poly(propylene imine) third generation dendrimers. Fluorescence and transmission electron microscopy revealed that Au nanoparticle conjugates were directed to mitochondria upon transfection, causing partial rupture of the outer mitochondrial membrane, triggering cell death. The ability to target Au nanoparticles into mitochondria of breast cancer cells and induce apoptosis reveals an alternative application of Au nanoparticles in photothermal therapy of cancer.

Stroke prevention in elderly patients with atrial fibrillation: challenges for anticoagulation

Elderly patients with atrial fibrillation (AF), who constitute almost half of all AF patients, are at increased risk of stroke. Anticoagulant therapies, especially vitamin K antagonists (VKA), reduce the risk of stroke in all patients including the elderly but are frequently under-used in older patients. Failure to initiate VKA in elderly AF patients is related to a number of factors, including the limitations of current therapies and the increased risk for major haemorrhage associated with advanced age and anticoagulation therapy. Of particular concern is the risk of intracranial haemorrhages (ICH), which is associated with high rates of mortality and morbidity. Novel oral anticoagulant agents that are easier to use and might offer similar or better levels of stroke prevention with a similar or reduced risk of bleeding should increase the use of antithrombotic therapy in the management of elderly AF patients. Amongst these new agents, the recently approved direct thrombin inhibitor dabigatran provides effective stroke prevention with a significant reduction of ICH, and enables clinicians to tailor the dose according to age and haemorrhagic risk.

Economic evaluation of dabigatran etexilate for the prevention of venous thromboembolism in patients aged over 75 years or with moderate renal impairment undergoing total knee or hip replacement

Oral dabigatran etexilate is indicated for the prevention of venous thromboembolism (VTE) in patients undergoing total knee replacement or total hip replacement. We investigated the cost-effectiveness of the 150 mg once daily (od) dose recommended for patients aged over 75 or with moderate renal impairment, from a United Kingdom National Health Service perspective. Dabigatran etexilate was compared with subcutaneous enoxaparin 40 mg od, using a decision model. Risks for VTE and bleeding were derived from subgroup analyses of the phase III trials. Dabigatran etexilate was less costly than enoxaparin; cost savings varied from pound62 to pound274 (base-case analyses) and were primarily due to differences in administration costs. Results were robust across a range of sensitivity analyses. Dabigatran etexilate 150 mg od is cost saving compared with enoxaparin 40 mg od in patients aged over 75years and in patients with moderate renal impairment, with comparable efficacy and safety.

Global risk management in type 2 diabetes: blood glucose, blood pressure, and lipids--update on the background of the current guidelines

Diabetes mellitus presents a significant public health burden based on its increased morbidity, mortality, and economic cost. The high comorbidity and prevalence of concomitant diseases like hypertension and dyslipidemia in diabetic patients cause the high risk in developing secondary, cost intensive, and for the patient often disastrous late complications (nephropathy, retinopathy, neuropathy, and cardiovascular disease). Therefore, patients with diabetes mellitus need a global risk management that takes the various individual clinical problems into account. The current global standards of therapy in patients with diabetes mellitus are focused on the control of glycemia, blood pressure, and lipid levels, as well as aspirin therapy and avoiding of smoking. There are a number of guidelines and recommendations to manage these global issues. Our review will summarize current recommendations and consolidate therapeutic goals and treatments that are of vital importance in the global risk management in diabetic patients.

[Safety and antihypertensive efficacy of the dihydropyridine calcium antagonist Amlodipine besylate--results from an observational study in 9,672 patients]

OBJECTIVES

This observational study investigated prescription behavior and the efficacy and safety of Amlodipine besylate in hypertensive patients.

METHODS

9,672 hypertensive patients were treated with Amlodipine besylate 5-10 mg/day for 12 weeks. At the end of the observation period, the participating physicians were asked to give their subjective evaluation of the efficacy and safety of treatment with Amlodipine besylate as well as their therapeutic considerations regarding the use of Amlodipine besylate.

RESULTS

55.2% of the patients received Amlodipine besylate in combination with other antihypertensive agents. The mean baseline blood pressure was 168.0/96.7 mmHg and the mean blood pressure reduction achieved at the end of the observation period was -28.5/-14.5 mmHg. In 80.3% of the total population, a reduction to diastolic blood pressure values of < 90 mmHg was achieved. A reduction to systolic blood pressure values of < 140 mmHg was obtained in 41.6% of the patients. Adverse events were reported by only 1.2% of the patients. For the vast majority of the patients, efficacy (96.6%) and safety (98.9%) were rated "very good" or "good" by their physicians. 24-hour efficacy with once daily dosing was given as the most important argument for using Amlodipine besylate.

CONCLUSION

The observation study confirmsthat Amlodipine besylate is an effective and safe antihypertensive drug both in mono and combination therapy.

Expression and distribution of the prolactin receptor in normal rat liver and in experimental liver cirrhosis

Recent results have suggested a role for prolactin (PRL) as a regeneration factor in the liver. In order to investigate the involvement of prolactin in the pathogenesis of liver cirrhosis, we studied the expression of the prolactin receptor (PRLR) and PRL during the development of cirrhosis in an animal model. 30 male rats were exposed to CCl4 by inhalation. Phenobarbitone was added to the drinking water to accelerate the formation of toxic metabolites by enzyme induction. Two control groups of 30 animals each were treated with phenobarbitone only or received no treatment. 10 animals of each group were sacrificed 35, 55, and 70 days after initiation of treatment. Liver tissue was subjected to histological examination, which demonstrated fibrosis of different grades and cirrhosis in the CCl4-treated rats. Expression of PRLR mRNA was investigated by mRNA extraction, RT-PCR and computer-supported densitometric evaluation. Compared to control liver, PRLR mRNA was expressed at a higher level in fibrotic and cirrhotic liver specimens. In normal tissue, immunohistochemical staining showed a high concentration of PRLR around the central vein and in the epithelium of the bile ducts. This pattern of distribution was lost in fibrosis and cirrhosis. An accumulation of PRLR was demonstrated within the damaged cells. Neither PRL nor PRL mRNA was detectable in normal, fibrotic, or cirrhotic liver. We conclude that PRLR is distributed in normal rat liver in a typical pattern which is lost with increasing fibrosis. PRL is not produced by rat liver, indicating that PRL does not act through autocrine or paracrine mechanisms.

Prognostic value of codon 918 (ATG-->ACG) RET proto-oncogene mutations in sporadic medullary thyroid carcinoma

We have determined the frequency of 918 RET proto-oncogene mutations (ATG-->ACG) in primary MTC tumors and metastases and correlated the presence or absence of this mutation with the clinical outcome of patients suffering from sporadic medullary thyroid carcinoma (MTC). A total of 197 samples, consisting of both primary tumors and lymph node metastases from 34 patients with sporadic MTC, were collected for PCR analysis of the RET 918 mutation. In 75 of the samples (38%), codon 918 (ATG-->ACG) mutations could be detected. The mutations showed a heterogeneous distribution: 21/34 patients (62%) had mutations in at least 1 tumor sample, and in 13 patients (38%) the mutation was present in all examined samples. Patients were considered 918mt when at least 1 tumor sample showed the RET 918 mutation. These 918mt and 918 wild-type (918wt) patients did not differ significantly concerning sex, age at diagnosis, TNM stage at diagnosis, number of examined tumor samples or follow-up time. However, 918mt patients showed more aggressive development of distant metastases during follow-up (p = 0.032, Fisher's exact test) with decreased metastases-free survival (p < 0.005, log-rank test). Furthermore, 918mt patients had a significantly lower survival rate than 918wt patients (p = 0.048, log-rank test). These data show that the RET codon 918 mutation has a prognostic impact on patients with sporadic MTC which may influence follow-up treatment.

Sell now. New pension law encourages early sale

The time to begin planning your retirement is long before you actually quit working. Changes in the federal pension law allow you to shorten that planning timetable. By taking advantage of these changes, you will be preparing for a better life for yourself and your entire family.

Duct changes and K-ras mutations in the disease-free pancreas: analysis of type, age relation and spatial distribution

Recent molecular studies have suggested that hyperplastic duct lesions of the pancreas are potential precursors of pancreatic ductal carcinoma. This study examines the type, distribution, age-related incidence and K-ras codon 12 mutation rate of duct lesions in the normal pancreas. Postmortem pancreases from 140 patients were screened for the presence of mucinous cell hypertrophy (MHT), ductal papillary hyperplasia (DPH), adenomatoid ductal hyperplasia (ADH), and squamous metaplasia (SQM). Microdissected cell samples were analyzed for K-ras codon 12 mutations by polymerase chain reaction amplification of exon 1 of the K-ras gene, combined with constant denaturing gel electrophoresis, and analyzed by sequencing. Of the 140 specimens 114 showed duct lesions. The lesions were evenly distributed throughout the pancreas. They were more common beyond the age of 40. MHT was present in 68%, DPH in 36%, ADH in 40%, and SQM in 36% of the cases. K-ras mutations were found in 19 samples from 15 out of 79 pancreases (18%), including all types of duct lesions and a variant of ADH with dense stroma. 67% of the K-ras-positive specimens showed the transition GGT to GAT (8) or GTT (5). Hyperplastic/metaplastic duct changes of the pancreas increase with age, but their distribution pattern in the pancreas differs from that of ductal carcinomas.

Octreotide (somatostatin analog) treatment reduces endothelial cell dysfunction in patients with diabetes mellitus

Octreotide is a long-acting somatostatin analog that has been shown to have various effects in diabetes. This study was performed to evaluate whether octreotide affects the vascular complications of diabetes mellitus. Albuminuria and serum thrombomodulin were used as markers of vascular and renal dysfunction. We studied the effect of octreotide in 27 patients with insulin-dependent diabetes mellitus (IDDM). They received 200 microg octreotide per day over a period of 6 months. As a marker of endothelial cell damage, we measured the serum thrombomodulin level. We also measured urinary albumin excretion, hemoglobin A1c (HbA1c), insulin-like growth factor-1 (IGF-1), and other parameters. IGF-1 decreased from 123 ng/mL before treatment to 114 ng/mL after 6 months of octreotide treatment (P = .009), while no significant change was observed in the unblinded control group (from 103 ng/mL to 102 ng/mL after 6 months of treatment). Urinary albumin excretion in patients with macroalbuminuria declined from 1,124 mg/L before octreotide treatment to 556 mg/L after 6 months of treatment (P < .05), whereas no change was observed in the control group. There was also a reduction of the plasma thrombomodulin level from 61.8 ng/mL to 46.1 ng/mL (P < .07) after 6 months of treatment. Furthermore, HbA1c decreased from 8.75% +/- 1.27% to 8.12% +/- 1.23% (P < .07) after octreotide treatment.

The J558 VH CDR3 region contributes little to antibody avidity; however, it is the recognition element for cognate T cell control of the alpha(1-->3) dextran-specific antibody response

Analysis of the humoral immune response of BALB/c mice to alpha(1-->3) dextran (Dex) reveals novel aspects of T cell-mediated control of 'type 2 thymus-independent' responses against polysaccharide antigens. The IgM and IgG antibody response, dominated by the J558 idiotype (Id), is controlled by Id-specific T cells. These regulatory T cells, for which the T cell clone 178-4 Ts with characterized TCR alpha and beta chain sequences is the prototype, expand in all BALB/c mice upon immunization with Dex. They suppress in a cognate interaction the expansion of J558 Id-bearing B cells, committed for production of IgG antibodies. Furthermore they provide a gate which precludes variability in the VH CDR3 region of IgG antibodies appearing occasionally in the periphery. The VH CDR3 region is the recognition element of 178-4 Ts analogous T cells but contributes little to affinity for the antigen. For recognition by 178-4 Ts cells not even minimal sequence deviations of the J558 Id peptide are allowed. The tight germline programmed complementarity between J558 Id-bearing Dex-specific B and J558 Id-specific 178-4 Ts analogous T cells leaves little room on both sides for ontogenetic variability.

Relaxant effect of xenin on rat ileum is mediated by apamin-sensitive neurotensin-type receptors

The action of xenin, a novel 25-residue peptide of the neurotensin (NT)/xenopsin family, was investigated in isolated rat ileal muscle strips and in dispersed longitudinal smooth muscle cells of rat small intestine in vitro. Xenin relaxes KCl-precontracted ileal strips dose dependently (1 nM-3 microM). The order of potency of the investigated peptides was as follows: xenopsin = NT = xenin > neuromedin N. Kinetensin was inactive. Tetrodotoxin, hexamethonium, tetraethylammonium, 4-aminopyridine, and NG-nitro-L-arginine did not influence the relaxant effects of xenin or NT, whereas the K+ channel blocker apamin nearly abolished their effects. Desensitization against one of the peptides or blockade of NT receptors by SR-48692 prevented the effect of xenin and NT. Structure-activity experiments revealed that the COOH-terminal part of the molecules of xenin and NT is essential for biological activity. Experiments with isolated dispersed smooth muscle cells and binding studies on intestinal smooth muscle cell membranes confirmed and extended the results obtained with muscle strips. In conclusion, xenin relaxes rat ileal smooth muscle via a muscular NT-type apamin-sensitive receptor.

[Insulin-dependent diabetes mellitus. Current aspects of morphology, etiology and pathogenesis]

Type I and type II diabetes are the most common types of diabetes. The ratio of type I to type II diabetes is about 1:9. Type I diabetes is caused by an absolute insulin deficiency and is therefore referred to as insulin-dependent diabetes. The disease becomes manifest clinically in childhood or adolescence ("juvenile diabetes"), although manifestation in adulthood is being increasingly observed. Morphologically, a subtotal (> 80%) to total loss of beta cells in the pancreatic islets occurs. Lymphocytic insulitis, which disappears after the beta cells have been totally destroyed, is pathognomonic of type I diabetes. This insulitis is an expression of an autoimmune event that is triggered by a multitude of factors. An important factor appears to be a genetic predisposition (HLA DR3/DR4/DQ8) in connection with as yet unknown environmental factors (e.g., viruses). Autoantibodies, such as islet cell cytoplasmic antibodies (ICA), insulin autoantibodies (IAA), and/or autoantibodies to the GABA-synthesizing enzyme glutamic acid carboxylase (GAD), are already detectable in a prediabetic phase, although it is not possible to predict the time of clinical manifestation. The course of the disease is dependent on age. Young children require insulin therapy sooner than juveniles or adults.

Human galanin modulates human colonic motility in vitro. Characterization of structural requirements

BACKGROUND

Human galanin (hGal) is a 30-residue non-amidated gut-brain peptide that shows considerable sequence divergence compared with galanin (Gal) forms of other species. Conflicting results have been reported with regard to the structural requirements for its modulatory action on gut motility.

METHODS

We investigated the effect of human and rat Gal and substituted analogues of Gal on the contractility of longitudinal muscle strips of the human colon in vitro.

RESULTS

Both hGal and rGal contracted the preparations in a concentration-dependent and tetrodotoxin-resistant manner without difference in sensitivity. The NH2-terminally truncated peptides hGal (3-30) and rGal (3-29) were inactive, whereas the NH2-terminal fragments, hGal (1-21) and rGal (1-18), remained fully responsive. Single amino acid substitutions at NH2-terminal positions showed divergent results: substitution of Trp2 reduced significantly potency and efficacy, whereas substitutions at positions 1, 3, 4, or 5 did not markedly modify the bioactivity of Gal. Galantide, a high-affinity Gal antagonist in the central nervous system, is a full agonist in human colonic smooth muscle.

CONCLUSION

The COOH-terminal part of Gal contributes mainly the receptor-binding affinity of the peptide, whereas the NH2-terminal region is essential for biologic activity.

Blindness due to electrocoagulation following functional endoscopic sinus surgery

A case is presented with irreversible blindness in one eye and restriction of the infratemporal visual field in the other eye, due to electrocoagulation performed for delayed bleeding after functional endoscopic sinus surgery (FESS). Although blindness due to rhinosurgery is a well-known, but rare complication, a review of the recent literature did not reveal a similar incident. The use of electrocoagulation especially under conditions of poor visualization, that may be the case in post-operative bleeding following (endoscopic) sinus surgery, is strongly discouraged.

[Etiology and pathogenesis of insulin-dependent diabetes mellitus]

Type I and type II diabetes are the most common types of diabetes. The ratio of type I to type II diabetes is about 1:9. Type I diabetes is caused by absolute insulin deficiency and is therefore referred to as insulin-dependent diabetes. The disease becomes manifest clinically in childhood or adolescence ("juvenile diabetes"), though manifestation in adulthood is increasingly being observed. Morphologically a subtotal (> 80%) to total loss of beta cells in the pancreatic islets occurs. Lymphocytic insulitis, which disappears after the beta cells have been totally destroyed, is pathognomonic of type I diabetes. This insulitis is an expression of an autoimmune event that is triggered by a multitude of factors. An important factor appears to be a genetic predisposition (HLA DR3/DR4/DQ8) in connection with as yet unknown environmental factors (e.g., viruses). Autoantibodies, such as islet cell cytoplasmic antibodies (ICA), insulin autoantibodies (IAA) and/or autoantibodies to the GABA-synthesizing enzyme glutamic acid carboxylase (GAD), are already detectable in a prediabetic phase, though it is not possible to predict the time of clinical manifestation. The course of the disease is dependent on age. Young children require insulin therapy sooner than juveniles or adults.

The biological relevance of gastric neuroendocrine tumors

Gastric neuroendocrine tumors were originally thought to have a low incidence (three percent). Since endoscopic diagnostic procedures have become clinical routine, they are now found more frequently (relative incidence up to 41 percent). In recent years, classifications have been developed that attempt to consider the biological relevance of these tumors. Four types of gastric neuroendocrine tumor may be distinguished: Type 1 gastric neuroendocrine tumor is most common. It is associated with chronic atrophic fundus gastritis, hypergastrinemia and often with pernicious anemia. Usually it is multicentric and smaller than one cm, does not produce any symptoms and has an excellent prognosis. Type 2 gastric neuroendocrine tumor is second in frequency. It has no association with other diseases, is solitary and has no predilection for a particular localization. It may be larger than 1 cm, produce a carcinoid syndrome or Zollinger-Ellison syndrome and have a metastasis rate of up to 30 percent. Type 3 gastric neuroendocrine tumor is rare and always associated with Zollinger-Ellison syndrome and multiple endocrine neoplasia type I. It occurs as multiple lesions in the gastric body fundus and has a lower metastatic rate than type 2 gastric neuroendocrine tumor. Type 4 gastric neuroendocrine tumor corresponds to a small-cell carcinoma.

PACAP is a stimulator of neurogenic contraction in guinea pig ileum

The myotropic effect of pituitary adenylate cyclase-activating polypeptide (PACAP), a novel brain-gut peptide with high sequence homology to vasoactive intestinal polypeptide (VIP), was studied in the isolated guinea pig ileum in vitro. PACAP contracts the guinea pig ileum significantly more potently and efficiently compared with VIP. PACAP-induced contraction was abolished by tetrodotoxin, dynorphin, and somatostatin, partially reduced by atropine, and not affected by ganglionic and adrenergic blockade. The atropine-resistant component was sensitive to spantide, to the induction of tachyphylaxis with substance P, and to omega-conotoxin. Ileal strips desensitized to PACAP did not respond to VIP, although they maintained their sensitivity to PACAP after desensitization to VIP. COOH-terminal-truncated derivatives of PACAP exhibited full biological activity, although some of them showed substantially reduced potency. Deletion of NH2-terminal amino acids abolished biological activity. PACAP produced a concentration-dependent increase in the release of [3H]acetylcholine from longitudinal muscle-myenteric plexus preparations preloaded with [3H]choline. This effect was Ca2+ dependent, tetrodotoxin sensitive, and resistant to hexamethonium and scopolamine. In contrast, PACAP inhibited release of acetylcholine evoked by field stimulation. In summary, PACAP-induced contraction of the guinea pig ileum is mediated via release of acetylcholine and substance P through interaction with PACAP-1 and VIP/PACAP-2 receptors. PACAP has to be added to the list of myotropic neuropeptides of the gastrointestinal tract.

Pituitary adenylate cyclase-activating peptide is a potent modulator of human colonic motility

Pituitary adenylate cyclase-activating peptide (PACAP) represents a novel brain-gut peptide with high sequence homology to vasoactive intestinal polypeptide (VIP). Since PACAP has been identified in the human gut, the effect of the two molecular forms PACAP-(1-38) and PACAP-(1-27), the hybrid PACAP-(1-23)VIP-(24-28), and VIP on the contractility of the longitudinal muscle of human sigmoid colon was tested in vitro. All peptides inhibited the spontaneous phasic contractions and relaxed concentration-dependently carbachol-precontracted preparations. The effects of the peptides remained unaffected by tetrodotoxin, by inhibition of phosphodiesterase activity, and by inhibition of nitric oxide synthesis. Apamin reduced only the effects of the PACAP peptides, whereas tetraethylammonium blocked only the effect of VIP. In conclusion, PACAP peptides and VIP mediate their relaxant effects via activation of specific PACAP and VIP receptors coupled to different potassium channels.

Pituitary adenylate cyclase activating polypeptide (PACAP) is a potent relaxant of the rat ileum

The effect and mode of action of pituitary adenylate cyclase activating polypeptide (PACAP) were studied in rat ileal strips. PACAP relaxed, concentration dependently, rat ileum and was 50 times more potent than the structurally related vasoactive intestinal polypeptide (VIP). The inhibitory action of PACAP was not modified by TTX, omega-conotoxin, adrenergic, or ganglionic blockade, antagonists of adrenoreceptors and muscarinic receptors, indicating a direct myogenic effect probably through specific PACAP receptors. The lack of cross-tachyphylaxis between PACAP and VIP suggests that both peptides act by activation of distinct receptors. Structure-function analysis revealed that the N-terminal region of the PACAP molecule is crucial for biological activity.

Benign intracranial hypertension as a cause of transient partial pituitary deficiency

A male patient is reported with benign intracranial hypertension, who presented with three periods of partial pituitary deficiency, corresponding to episodes of headaches and papilledema. No radiological signs of the empty sella syndrome were observed. Since benign intracranial hypertension has been implicated in the development of the empty sella syndrome, it is postulated that the endocrine deficiency syndrome encountered in the empty sella syndrome can be provoked by chronic intracranial hypertension in itself and is not necessarily secondary to the anatomical changes occurring in the sellar region.

[Optic neuritis in non-Hodgkin's lymphoma]

Optic neuropathy during non-Hodgkin lymphoma is a late central nervous system complication of unfavourable prognosis. It appears especially with involvement of the bone marrow. A normal cerebrospinal fluid, lack of any beneficial effect of the chemo-corticotherapy and absence of papilledema suggest paraneoplastic, or iatrogenic (radio and (or) chemotherapeutic) neuropathy with conclusive histopathological proof only at autopsy. More frequently, cerebrospinal fluid containing malignant cells, papilledema and a beneficial effect of the chemocortico-therapy suggests malignant infiltration of the optic nerve as occurs in our case. Optic neuropathy during non-Hodgkin lymphoma may exceptionally precede the systemic disease by several years. Early oculomotor involvement suggests meningeal malignant infiltration as found in meningeal carcinomatosis.

Vasoactive intestinal polypeptide induces neurogenic contraction of guinea-pig ileum. Involvement of acetylcholine and substance P

The effect and mode of action of vasoactive intestinal polypeptide (VIP), a peptidergic neuromodulator in the gastrointestinal nervous system, were investigated in isolated muscle strips of the guinea-pig ileum. VIP induced concentration-dependent (20 nM-1 microM) contractions of longitudinal ileal strips. TTX (1 microM), a mixture of atropine (3 microM) and spantide (30 microM), a mixture of atropine (3 microM) and omega-conotoxin GVIA (100 nM), somatostatin (60 nM) and dynorphin (100 nM) abolished the effect of VIP. In most cases a small relaxation became evident. Desensitization to substance P in the presence of atropine prevented VIP-induced contraction. A partial inhibition was observed in the presence of atropine (3 microM), spantide (30 microM), omega-conotoxin GVIA (100 nM), beta-endorphin (265 nM), met-enkephalin (1100 nM) and a mixture of spantide (30 microM) and omega-conotoxin GVIA (100 nM). The action of VIP was not significantly modified by guanethidine (3 microM) or hexamethonium (150 microM). In circular ileal strips VIP (10-300 nM) caused concentration-dependent relaxations through a direct myogenic effect. These results indicate that the VIP produced contractions of the guinea-pig ileum are exclusively neurally mediated and involve a cholinergic as well as a noncholinergic-nonadrenergic (NANC) pathway. It is concluded that besides acetylcholine (Ach) VIP releases the peptidergic transmitter substance P from postganglionic nerve fibers of myenteric plexus. Opioid peptides and somatostatin modulate the activity of cholinergic and peptidegic nerves in the guinea-pig ileum. The release of substance P appears to depend completely on N-type voltage sensitive calcium channels.

Blindness following paranasal sinus surgery: a report of two cases

Two cases of blindness following paranasal sinus surgery are presented. The first patient, a 38-year old man, developed a delayed massive haemorrhage, after bilateral sphenoethmoidectomy. This hemorrhage could be stopped by electric cauterisation under endoscopical control. During this reintervention the patient developed total blindness of his right eye, and a restriction of the inferotemporal left visual field. The second patient, a 10-year old girl, developed, after bilateral spheno-ethmoidectomy for isolated sphenoiditis, total blindness of the left eye and paralysis of the ipsilateral extraocular muscles. According to the literature, blindness secondary to paranasal surgery is mainly due to retrobulbar hemorrhage. In the first case blindness was due to a direct cauterisation of the optic nerve, after perforation of the lamina papyracea. In the second case, blindness was probably due to a hemorrhage in the orbital apex.

Isolation and primary structure of pituitary human galanin, a 30-residue nonamidated neuropeptide

Galanin (Gal), a 29-amino acid C-terminally amidated neuropeptide, is widely distributed throughout the central and peripheral nervous system. The primary structures of rat and bovine Gals were derived from the cDNA sequences of their precursors. To elucidate the structure of human Gal (hGal), we extracted 280 postmortem pituitaries in trifluoroacetic acid and purified hGal binding activity, by three successive HPLC steps, to homogeneity based on a radioreceptor assay. The primary structure of hGal was determined by automatic Edman degradation to be Gly-Trp-Thr-Leu-Asn-Ser-Ala-Gly-Tyr-Leu-Leu- Gly-Pro-His-Ala-Val-Gly-Asn-His-Arg-Ser-Phe-Ser-Asp-Lys-Asn-Gly-Leu-Thr- Ser-COOH. The structure was confirmed by plasma desorption time-of-flight mass spectrometry, revealing a mass of 3156.1. Compared to the 29-residue porcine, rat, and bovine Gals, hGal uniquely comprises 30 amino acids possessing an additional nonamidated serine residue as C terminus. The nonamidated carboxylic group at the C terminus was proven by synthesis of amidated and nonamidated hGal and by mass spectrometry after selective methylation of all free carboxylic groups. Synthetic hGal possesses full biological activity on isolated rat fundus muscle strips.

Routine coronary angiography for effort angina

OBJECTIVE

To compare the value of exercise testing and coronary angiography in the management of patients with effort angina.

DESIGN

A retrospective follow-up study.

SETTING

A university teaching hospital.

PATIENTS

Four hundred and thirty-four patients with a history of angina, who developed pain or ST segment changes during an exercise test and who were followed-up at up to nine years after their exercise test.

INTERVENTIONS

Coronary angiography was offered to patients for disabling angina only. Bypass surgery was generally offered to patients with multiple vessel coronary artery obstruction.

MAIN OUTCOME MEASURE

Patient survival.

RESULTS

Stepwise regression analysis based on the Cox proportional hazards model indicated that the decision to perform coronary angiography (P less than 0.001) and the amount of ST segment depression on exercise testing (P less than 0.01) were predictors of survival. With ST segment depression set at 1 mm and age set at 53.5 years (both sample median values) the probability of survival at five years was 86% in patients who did not undergo coronary angiography compared with 96% in patients who did undergo angiography. There were eight deaths in 59 patients who did not show any ST segment depression during the exercise test and who were treated medically without coronary angiography.

CONCLUSIONS

Coronary angiography is a superior technique to exercise testing for detecting patients with effort angina who are at high risk of premature mortality. Coronary bypass surgery makes a big improvement in the chance of five-year survival in such patients.

Malignant peripheral nerve sheath tumor and pheochromocytoma. A composite tumor of the adrenal

An adrenal composite tumor of pheochromocytoma and malignant peripheral nerve sheath tumor (PNST) is described in a 39-year-old woman in whom PNST component appeared to have undergone further malignant degeneration, resulting in a highly anaplastic sarcoma with rapidly progressive clinical course.