Lipoamino acid and liposaccharide conjugates of somatostatin analogue TT-232 were synthesized to modify the physicochemical properties of the parent peptide. The relative position, the number, and the nature of the li...
详细信息
Lipoamino acid and liposaccharide conjugates of somatostatin analogue TT-232 were synthesized to modify the physicochemical properties of the parent peptide. The relative position, the number, and the nature of the lipid and/or saccharide moieties were varied. Experiments in vitro clearly showed that many compounds modified at the N- and/or C-terminus with lipid or sugar moieties retained the biological activity of the parent compound. An interesting construct was synthesized containing lipid and sugar units at opposite ends of the somatostatin analogue, so that the entire molecule could be considered as an amphipathic surfactant.
1. Somatostatin depresses the ventilatory response to hypoxia (AHVR). This study sought to determine whether somatostatin also reduced the peripheral chemoreflex sensitivity to hypercapnia, and if so, whether this was...
详细信息
1. Somatostatin depresses the ventilatory response to hypoxia (AHVR). This study sought to determine whether somatostatin also reduced the peripheral chemoreflex sensitivity to hypercapnia, and if so, whether this was related to the reduction in AHVR. 2. Nine subjects completed the study. AHVR and the ventilatory responses to hypercapnia under both hyperoxic and hypoxic conditions were assessed both without and with an infusion of somatostatin (0.5 mg h(-1)). Peripheral (fast) and central (slow) responses to hypercapnia were distingushed by use of a multi-frequency binary sequence input in end-tidal P-CO2 (P-ET,P-CO2) that included 13 steps into and out of hypercapnia. 3. The acute ventilatory response to a reduction in end-tidal P-O2 (P-ET,P-O2) from 100 to 50 Torr (at a P-ET,P-CO2 of +1.5-2.0 Torr above normal) was reduced from (mean +/- S.E.M.) 16.4 +/- 3.3 to 9.5 +/- 3.21 min(-1) (P < 0.005, Student's t test) by somatostatin. The magnitude of the ensuing hypoxic ventilatory decline was unaltered (8.8 +/- 2.7 l min(-1) in control vs. 8.0 +/- 2.9 l min(-1) with somatostatin). 4. The peripheral chemoreflex sensitivity to CO2 in hypoxia was reduced from 2.42 +/- 0.36 to 1.18 +/- 0.20 l min(-1) Torr(-1) (P < 0.005) with somatostatin. The reduction under hyperoxic conditions from 0.75 +/- 0.34 to 0.49 +/- 0.09 l min(-1) Torr(-1) did not reach significance. Central chemoreflex sensitivity to CO2 was unchanged. Changes in peripheral chemoreflex sensitivity to CO2 in hypoxia correlated with changes in AHVR. 5. We conclude that peripheral chemoreflex sensitivity to CO2 is reduced by somatostatin, probably via the same mechanism as that by which somatostatin exerts its effects on AHVR.
Cortical administration of SRIF in unrestrained, freely moving rats produced an early activation, stereotyped behavior patterns and later, coordination difficulties often associated with drowsiness. A few animals show...
详细信息
Cortical administration of SRIF in unrestrained, freely moving rats produced an early activation, stereotyped behavior patterns and later, coordination difficulties often associated with drowsiness. A few animals showed a tendency toward paraplegia-in-extension. A considerable, prolonged alteration in the sleep-waking cycle was also observed. Similar results were obtained in both intact and hypophysectomized animals. Intraperitoneal administration of SRIF induced several other effects in addition to those seen after cortical application. The latter were however, restricted in variety, intensity and duration.
It is well-known that morphine is the king of analgesics. It is widely used, and administered in various ways for the control of acute and chronic pain states. There are, however, certain types of pain and certain cli...
详细信息
It is well-known that morphine is the king of analgesics. It is widely used, and administered in various ways for the control of acute and chronic pain states. There are, however, certain types of pain and certain clinical conditions in which morphine cannot be used due to the risk of possible complications. These are usually pain states associated with intracranial hypertension, the presence of serious respiratory problems, the onset of major opioid tolerance, persistent vomiting, and so on. The search for "alternative analgesics" has been in progress for a decade, alternatives that could be used alone or in combination for spinal administration in the treatment of complex chronic pain states and with a low incidence of secondary effects. Today, research is carefully assessing the clinical effectiveness and the side effects of a series of drugs for spinal administration, that is, epidural or intrathecal, such as the new narcotics, alpha-2 agonists, central muscle relaxants, calcitonin, and local anesthetics. In this alternative analgesic category we have to mention the somatotrophin-release inhibiting factor (SRIF), which is an ubiquitous native hormone with widespread, predominantly inhibitory actions, and octreotide, its synthetic analogue. In this article we review the literature on the natural drug and its synthetic analogue, paying particular attention to the problems connected with intraspinal administration and analgesic properties.
Chylothorax is a rare but serious postoperative complication of thoracic surgical procedures. We report the case of a 77-year-old man who underwent a coronary artery bypass procedure using a left internal mammary arte...
详细信息
Chylothorax is a rare but serious postoperative complication of thoracic surgical procedures. We report the case of a 77-year-old man who underwent a coronary artery bypass procedure using a left internal mammary artery pedicle graft. A permanent pacemaker was required postoperatively. A persistent postoperative chylothorax developed necessitating continuous drainage and conservative management. Somatostatin was instituted when after 1 week this management failed to resolve the chylothorax. This led to rapid cessation of chyle production. Enteral feeding was reinstituted without complication and surgical intervention was avoided. (C) 2000 by The Society of Thoracic Surgeons.
暂无评论