Peptide Toxins from Antarctica: The Nemertean Predator and Scavenger (McIntosh, 1876).

Peptide toxins from marine invertebrates have found use as drugs and in biotechnological applications. Many marine habitats, however, remain underexplored for natural products, and the Southern Ocean is among them. Here, we report toxins from one of the top predators in Antarctic waters: the nemertean worm (McIntosh, 1876).

Spatial Distribution and Stability of Cholinesterase Inhibitory Protoberberine Alkaloids from .

During a research program to identify new cholinesterase inhibitors of natural origin, two new 7,8-didehydroprotoberberine alkaloids ( and ) and nine known compounds (-) were isolated from the capsules of the common ornamental poppy, (previously ). Despite their reported instability, the 7,8-didehydroprotoberberines isolated herein appeared relatively stable, particularly as their trifluoroacetic acid salts. The spatial distributions of the isolated alkaloids were also analyzed using desorption electrospray ionization imaging mass spectrometry.

Functional Characterization of the Nemertide α Family of Peptide Toxins.

Peptide toxins find use in medicine, biotechnology, and agriculture. They are exploited as pharmaceutical tools, particularly for the investigation of ion channels. Here, we report the synthesis and activity of a novel family of peptide toxins: the cystine-knotted α nemertides.

Are Men Who Buy Sex Different from Men Who Do Not?: Exploring Sex Life Characteristics Based on a Randomized Population Survey in Sweden.

The buying and selling of sex is a topic of frequent discussion and a relevant public health issue. Studies of sex workers are available, while studies addressing the demand side of sex are scarce, especially based on robust population data. The current study provides national estimates of the prevalence of and factors associated with having paid for sex among men in Sweden.

Meeting Sexual Partners Online and Associations With Sexual Risk Behaviors in the Swedish Population.

Background: Online arenas may facilitate sexual encounters. However, to what extent finding sexual partners online is associated with sexual risk behavior and sexual health outcomes is still not fully explored.

Methods: A stratified randomized population based study on sexual and reproductive health and rights of 50,000 Swedes was conducted in 2017.

The Toxins of Nemertean Worms.

Most ribbon worms (phylum: Nemertea) are found in marine environments, where they act as predators and scavengers. They are characterized by an eversible proboscis that isused to hunt for prey and thick mucus covering their skin. Both proboscis and epidermal mucus mediate toxicity to predators and preys.

Peptide ion channel toxins from the bootlace worm, the longest animal on Earth.

Polypeptides from animal venoms have found important uses as drugs, pharmacological tools, and within biotechnological and agricultural applications. We here report a novel family of cystine knot peptides from nemertean worms, with potent activity on voltage-gated sodium channels. These toxins, named the α-nemertides, were discovered in the epidermal mucus of Lineus longissimus, the 'bootlace worm' known as the longest animal on earth.

Cyclotide Evolution: Insights from the Analyses of Their Precursor Sequences, Structures and Distribution in Violets ().

Cyclotides are a family of plant proteins that are characterized by a cyclic backbone and a knotted disulfide topology. Their cyclic cystine knot (CCK) motif makes them exceptionally resistant to thermal, chemical, and enzymatic degradation. By disrupting cell membranes, the cyclotides function as host defense peptides by exhibiting insecticidal, anthelmintic, antifouling, and molluscicidal activities.

The Bacterial (Vibrio alginolyticus) Production of Tetrodotoxin in the Ribbon Worm Lineus longissimus-Just a False Positive?

We test previous claims that the bacteria Vibrio alginolyticus produces tetrodotoxin (TTX) when living in symbiosis with the nemertean Lineus longissimus by a setup with bacteria cultivation for TTX production. Toxicity experiments on the shore crab, Carcinus maenas, demonstrated the presence of a paralytic toxin, but evidence from LC-MS and electrophysiological measurements of voltage-gated sodium channel-dependent nerve conductance in male Wistar rat tissue showed conclusively that this effect did not originate from TTX. However, a compound of similar molecular weight was found, albeit apparently non-toxic, and with different LC retention time and MS/MS fragmentation pattern than those of TTX.

Exogenous plant hormones and cyclotide expression in Viola uliginosa (Violaceae).

Plants from Violaceae produce cyclotides, peptides characterized by a circular peptide backbone and a cystine knot. This signature motif gives stability that can harness a wide spectrum of biological activities, with implications in plant defense and with applications in medicine and biotechnology. In the current work, cyclotide expressing in vitro cultures were established from Viola uliginosa.

Amygdala subregions tied to SSRI and placebo response in patients with social anxiety disorder.

The amygdala is a key structure in the pathophysiology of anxiety disorders, and a putative target for anxiolytic treatments. Selective serotonin reuptake inhibitors (SSRIs) and placebo seem to induce anxiolytic effects by attenuating amygdala responsiveness. However, conflicting amygdala findings have also been reported.

A link between serotonin-related gene polymorphisms, amygdala activity, and placebo-induced relief from social anxiety.

Placebo may yield beneficial effects that are indistinguishable from those of active medication, but the factors underlying proneness to respond to placebo are widely unknown. Here, we used functional neuroimaging to examine neural correlates of anxiety reduction resulting from sustained placebo treatment under randomized double-blind conditions, in patients with social anxiety disorder. Brain activity was assessed during a stressful public speaking task by means of positron emission tomography before and after an 8 week treatment period.

Cerebral blood flow changes after treatment of social phobia with the neurokinin-1 antagonist GR205171, citalopram, or placebo.

Background: Evidence is accumulating that pharmacological blockade of the substance P preferring neurokinin-1 (NK1) receptor reduces anxiety. This study compared the effects of an NK1 receptor antagonist, citalopram, and placebo on brain activity and anxiety symptoms in social phobia.

Methods: Thirty-six patients diagnosed with social phobia were treated for 6 weeks with the NK1 antagonist GR205171 (5 mg), citalopram (40 mg), or matching placebo under randomized double-blind conditions.

Distribution of zolmitriptan into the CNS in healthy volunteers: a positron emission tomography study.

Objective: Triptans are highly effective in the treatment of migraine. Both central and peripheral mechanisms of action have been suggested. Until now, firm data about the passage of triptans into the CNS in humans have been lacking.

Influence of nitrogen status on the bioconcentration of hydrophobic organic compounds to Selenastrum capricornutum.

Changes in algal nitrogen status that increase algal lipid content also affect the bioconcentration of hydrophobic organic compounds (HOCs). Bioconcentration factors (BCFs) for several HOCs increased up to nine times as the total algal lipid content of the green algae Selenastrum carpricornutum increased from 17 to 44% of the algal dry weight as a consequence of nitrogen starvation. An increase in total lipid from 17 to 44% should theoretically increase the BCFs by a factor of 2.

Sodium excretion and renin secretion after continuous versus pulsatile infusion of oxytocin in rats.

Neurohypophyseal oxytocin (OT), secreted continuously under conditions of hyperosmolality, is a potent natriuretic hormone in rats. In contrast, OT secretion during lactation is pulsatile and is not accompanied by increased urinary Na+ excretion. The present experiments compared the effects of continuous and pulsatile infusion of OT on natriuresis in rats.

Experimental partial ureteric obstruction in newborn rats. X. Renal function and morphology after unobstruction.

Partial obstruction of the left ureter was created in newborn rats. Unobstruction was performed after 2 or 7 days. The investigations were carried out at 9 weeks of age--under slight hydropenia to institute an element of stress.

Iodine concentrations in the rat kidney measured by X-ray microanalysis. Comparison of concentrations and viscosities in the proximal tubules and renal pelvis after intravenous injections of contrast media.

Purpose: To measure the iodine concentrations in the proximal tubules and renal pelvis after i.v. injections of contrast media (CM) at 1600 mg I/kg b.

Experimental partial ureteric obstruction in newborn rats. IX. Renal morphology and function after 1 year of obstruction.

Unfortunately, the nonoperative treatment of hydronephrosis, in wide use today, cannot be evaluated until after many decades. Long-term animal experiments offer a peekhole into the future. Partial obstruction of the left ureter was created in newborn rats.

Natriuresis obtained by intracerebroventricular infusion of hypertonic NaCl in rats with papillary necrosis.

Raising the sodium concentration in the third cerebral ventricle increases renal sodium, potassium and water excretion. The identification and characterization of the factor(s) mediating the centrally evoked natriuresis would be greatly facilitated if the exact intrarenal effector site were known. We have assessed the importance of inner medullary structures for the effects of CNS stimulation by examining its ability to alter renal excretion in rats with papillary necrosis, induced 2 d earlier with 2-bromoethylamine hydrobromide (BEA), 250 mg kg-1 body wt i.

Influence of allergy, asthma and hypertension on nasal polyposis.

Arterial hypertension was found in 78 of 224 consecutive patients operated for nasal polyposis. An exacerbated degree of hypertension was significant in groups aged above 50 years. In total, 46% of patients whose nasal polyposis lasted for more than 10 years suffered from hypertension.

Long-term partial ureteral obstruction and its effects on kidney function.

Previously it has been shown that partial ureteral obstruction present in young rats for 12 weeks results in small morphological changes in the kidney as well as slightly decreased kidney function. In the present study the aim was to examine whether rats obstructed for one year had more advanced changes in morphology and kidney function. The first group of animals examined after three weeks of obstruction showed only modest changes in kidney function with a reduced potassium concentration in the urine but no reduction in the glomerular filtration rate.

Sodium and potassium load in the loop of Henle, measured with intact and blocked tubuloglomerular feedback mechanism in juxtamedullary nephrons.

For the juxtamedullary nephrons only the loop of Henle is easily accessible for micropuncture. We have shown that the tubuloglomerular feedback (TGF) mechanism is highly activated in these nephrons. Techniques have been developed for measurements on these nephrons without disrupting the normal flow to the macula densa.

Nasal polyposis as a risk factor for hypertension.

Arterial hypertension was found in 78 of 224 consecutive patients operated for nasal polyposis. An exacerbated degree of hypertension was significant in groups aged above 50 years. In total, 46% of patients whose nasal polyposis was of a duration of more than 10 years suffered from hypertension.