D-aspartic acid in the nervous system of Aplysia limacina:possible role in neurotransmission

In the marine mollusk Aplysia limacina, a substantial amount of endogenous D-aspartic acid (D-Asp) was found following its synthesis from L-aspartate by an aspartate racemase. Concentrations of D-Asp between 3.9 and 4.6 μmol/g tissue were found in the cerebral, abdominal, buccal, pleural, and pedal ganglia. In non nervous tissues, D-Asp occurred at a very low concentration compared to the nervous system. Immunohistochemical studies conducted on cultured Aplysia neurons using an anti-D-aspartate antibody demonstrated that D-Asp occurs in the soma, dendrites, and in synaptic varicosities. Synaptosomes and synaptic vesicles from cerebral ganglia were prepared and characterized by electron microscopy. HPLC analysis revealed high concentrations of D-Asp together with L-aspartate and L-glutamate in isolated synaptosomes. In addition, D-Asp was released from synaptosomes by K+ depolarization or by ionomycin. D-Asp was one of the principal amino acids present in synaptic vesicles representing about the 25% of total amino acids present in these cellular organelles. Injection of D-Asp into live animals or addition to the incubation media of cultured neurons, caused an increase in cAMP content. Taken as a whole, these findings suggest a possible role of D-Asp in neurotransmission in the nervous system of Aplysia limacina. © 2005 Wiley-Liss, Inc

Role of nitric oxide- and vasoactive intestinal polypeptide-containing neurones in human gastric fundus strip relaxations

1. The morphological pattern and motor correlates of nitric oxide (NO) and vasoactive intestinal polypeptide (VIP) innervation in the human isolated gastric fundus was explored. 2. By using the nicotinamide adenine dinucleotide phosphate hydrogen (NADPH)-diaphorase and specific rabbit polyclonal NO-synthase (NOS) and VIP antisera, NOS- and VIP-containing varicose nerve fibres were identified throughout the muscle layer or wrapping ganglion cell bodies of the myenteric plexus. NOS-immunoreactive (IR) neural cell bodies were more abundant than those positive for VIP-IR. The majority of myenteric neurones containing VIP coexpressed NADPH-diaphorase. 3. Electrical stimulation of fundus strips caused frequency-dependent NANC relaxations. N(G)-nitro-L-arginine (L-NOARG: 300 μM) enhanced the basal tone, abolished relaxations to 0.3–3 Hz (5 s) and those to 1 Hz (5 min), markedly reduced (∼50%) those elicited by 10–50 Hz, and unmasked or potentiated excitatory cholinergic responses at frequencies ⩾1 Hz. L-NOARG-resistant relaxations were virtually abolished by VIP (100 nM) desensitization at all frequencies. 4. Relaxations to graded low mechanical distension (⩽1 g) were insensitive to tetrodotoxin (TTX: 1 μM) and L-NOARG (300 μM), while those to higher distensions (2 g) were slightly inhibited by both agents to the same extent (∼25%). 5. In the human gastric fundus, NOS- and VIP immunoreactivities are colocalized in the majority of myenteric neurones. NO and VIP mediate electrically evoked relaxations: low frequency stimulation, irrespective of the duration, caused NO release only, whereas shortlasting stimulation at high frequencies induced NO and VIP release. Relaxations to graded mechanical distension were mostly due to passive viscoelastic properties, with a slight NO-mediated neurogenic component at 2 g distension. The difference between NO and VIP release suggests that in human fundus accommodation is initiated by NO

IPOD Study: Management of Acute Left Colonic Diverticulitis in Italian Surgical Departments

BACKGROUND: In recent years, the emergency management of acute left colonic diverticulitis (ALCD) has evolved dramatically despite lack of strong evidence. As a consequence, management strategies are frequently guided by surgeon's personal preference, rather than by scientific evidence. The primary aim of IPOD study (Italian Prospective Observational Diverticulitis study) is to describe both the diagnostic and treatment profiles of patients with ALCD in the Italian surgical departments. METHODS: IPOD study is a prospective observational study performed during a 6-month period (from April 1 2015 to September 1 2015) and including 89 Italian surgical departments. All consecutive patients with suspected clinical diagnosis of ALCD confirmed by imaging and seen by a surgeon were included in the study. The study was promoted by the Italian Society of Hospital Surgeons and the World Society of Emergency Surgery Italian chapter. RESULTS: Eleven hundred and twenty-five patients with a median age of 62 years [interquartile range (IQR), 51-74] were enrolled in the IPOD study. One thousand and fifty-four (93.7%) patients were hospitalized with a median duration of hospitalization of 7 days (IQR 5-10). Eight hundred and twenty-eight patients (73.6%) underwent medical treatment alone, 13 patients had percutaneous drainage (1.2%), and the other 284 (25.2%) patients underwent surgery as first treatment. Among 121 patients having diffuse peritonitis, 71 (58.7%) underwent Hartmann's resection. However, the Hartmann's resection was used even in patients with lower stages of ALCD (36/479; 7.5%) where other treatment options could be more adequate. CONCLUSIONS: The IPOD study demonstrates that in the Italian surgical departments treatment strategies for ALCD are often guided by the surgeon's personal preference

IPOD Study: Management of Acute Left Colonic Diverticulitis in Italian Surgical Departments.

Background: In recent years, the emergency management of acute left colonic diverticulitis (ALCD) has evolved dramatically despite lack of strong evidence. As a consequence, management strategies are frequently guided by surgeon’s personal preference, rather than by scientific evidence. The primary aim of IPOD study (Italian Prospective Observational Diverticulitis study) is to describe both the diagnostic and treatment profiles of patients with ALCD in the Italian surgical departments. Methods: IPOD study is a prospective observational study performed during a 6-month period (from April 1 2015 to September 1 2015) and including 89 Italian surgical departments. All consecutive patients with suspected clinical diagnosis of ALCD confirmed by imaging and seen by a surgeon were included in the study. The study was promoted by the Italian Society of Hospital Surgeons and the World Society of Emergency Surgery Italian chapter. Results: Eleven hundred and twenty-five patients with a median age of 62 years [interquartile range (IQR), 51–74] were enrolled in the IPOD study. One thousand and fifty-four (93.7%) patients were hospitalized with a median duration of hospitalization of 7 days (IQR 5–10). Eight hundred and twenty-eight patients (73.6%) underwent medical treatment alone, 13 patients had percutaneous drainage (1.2%), and the other 284 (25.2%) patients underwent surgery as first treatment. Among 121 patients having diffuse peritonitis, 71 (58.7%) underwent Hartmann’s resection. However, the Hartmann’s resection was used even in patients with lower stages of ALCD (36/479; 7.5%) where other treatment options could be more adequate. Conclusions: The IPOD study demonstrates that in the Italian surgical departments treatment strategies for ALCD are often guided by the surgeon’s personal preference

IPOD Study: Management of Acute Left Colonic Diverticulitis in Italian Surgical Departments

Background: In recent years, the emergency management of acute left colonic diverticulitis (ALCD) has evolved dramatically despite lack of strong evidence. As a consequence, management strategies are frequently guided by surgeon’s personal preference, rather than by scientific evidence. The primary aim of IPOD study (Italian Prospective Observational Diverticulitis study) is to describe both the diagnostic and treatment profiles of patients with ALCD in the Italian surgical departments. Methods: IPOD study is a prospective observational study performed during a 6-month period (from April 1 2015 to September 1 2015) and including 89 Italian surgical departments. All consecutive patients with suspected clinical diagnosis of ALCD confirmed by imaging and seen by a surgeon were included in the study. The study was promoted by the Italian Society of Hospital Surgeons and the World Society of Emergency Surgery Italian chapter. Results: Eleven hundred and twenty-five patients with a median age of 62 years [interquartile range (IQR), 51–74] were enrolled in the IPOD study. One thousand and fifty-four (93.7%) patients were hospitalized with a median duration of hospitalization of 7 days (IQR 5–10). Eight hundred and twenty-eight patients (73.6%) underwent medical treatment alone, 13 patients had percutaneous drainage (1.2%), and the other 284 (25.2%) patients underwent surgery as first treatment. Among 121 patients having diffuse peritonitis, 71 (58.7%) underwent Hartmann’s resection. However, the Hartmann’s resection was used even in patients with lower stages of ALCD (36/479; 7.5%) where other treatment options could be more adequate. Conclusions: The IPOD study demonstrates that in the Italian surgical departments treatment strategies for ALCD are often guided by the surgeon’s personal preference