Effect of posture, route of respiration, and negative pressure on palatal muscle activity in humans

Sleep apnea is worse in the supine posture and is associated with retropalatal airway narrowing or occlusion. We have, therefore, examined the effects of posture, negative pressure, and route of respiration on palatal muscle activity in 13 nonsnoring awake male subjects by using electromyography. Electromyographic activity of the levator palatini and palatoglossus was expressed as a percentage of maximum activity. Both the levator palatini (P = 0.002) and palatoglossus (P = 0.002) exhibited phasic inspiratory activity. Overall, posture did not affect the levator palatini (F = 1.58; P = 0.23) or palatoglossus (F = 0.98; P = 0.34) activity, but analysis by route of respiration showed the palatoglossus to be more active when the subjects were nose breathing supine (F = 6.64; P = 0.02). Levator palatini activity was lower when nose breathing was compared with mouth breathing in both the erect and supine postures (F = 6.67; P < 0.02). Nose breathing with the mouth held open caused an increase in palatoglossal activity (P = 0.04). Negative-pressure application (0 to -12.5 cmH2O) caused significant increases in levator palatini (P < 0.001) and palatoglossus (P < 0.001) activity, 100 ms after pressure stimulus, irrespective of route. However, the palatoglossus required significantly greater negative pressures to cause activation when applied via the nose compared with the mouth (P < 0.05). These observations indicate that the levator palatini and palatglossus have respiratory activity and are reflexly activated by negative pressure.     

The NH2- and COOH-terminal amino acid sequence of nuclear protein A24

The NH2- and COOH-terminal sequence of nuclear portein A24 has been determined by automatic Edman degradation and carboxypeptidase A and B digestion. Protein A24 is of interest because it is composed in part of histone 2A (Goldknofp, I.L., and Busch, H., (1975) Biochem, Biophys. Res. Commun. 65, 951-960). The sequence of the first 37 NH2-terminal residues is: Met-Gln-Ile-Phe-Val-Lys-Thr-Leu-Thr-Gly-Lys-Thr-Ile-Thr-Leu-Glu-Val-Glu-Pro-Ser-Asp-Thr-Ile-Glu-Asn-Val-Lys-Ala-Lys-Ile-Gln-Asp-Lys-Glu-Gly-Ile-Pro- This sequence is not homologous to any known histone sequence. It contains regions of internal homology (italics). The COOH-terminal amino acid sequence is the same as that of histone 2A, naely: -His-His-Lys-Ala-Lys-Gly-Lys-COOH.     

Reversibility of glycolysis in leaves of C4-plants

A conversion of the reaction of two cytoplasmic glycolysis enzymes, phosphoglycerate mutase and phosphopyruvate hydratase, is necessary for sucrose synthesis from pyruvate in leaves of C4-plants in the light, when phosphoenolpyruvate synthesis from pyruvate and phosphoglycerate reduction can be carried out by chloroplasts. Leaves of C4-plants differ from those of C3-plants in a higher activity of cytoplasmic glycolysis enzymes, which are distributed irregularly in two assimilatory tissues. The ratio of pyruvate kinase and enolase reaction activities is high in parenchyma linings of vascular fascicles (where mitochondria are concentrated), and it is low in mesophyl tissue, where phosphoglucerate in equilibrium phosphoenolpyruvate reaction is included into photosynthetic metabolism. The data obtained on isolated mesophyl protoplasts have shown that the reaction equilibrium is sharply shifted into the direction of phosphoenolpyruvate formation from phosphoglycerate. However, the incorporation of 14C into sugars is not completely inhibited in the atmosphere of N2-A possibility of incorporation of tri-carbon fragments into sugars in photosynthesizing leaves via conversion of enolase reaction and via alternative pathways is discussed.     

Similar sensitivities of pancreatic and biliary secretion to cholecystokinin plus secretin infusion

The differing sensitivities of the gallbladder and pancreas to graded doses of CCK have been claimed as important in normal digestive events. As both secretin and CCK are thought to be released in response to normal feeding, we have reexamined the sensitivities of the gallbladder and pancreas to graded increases of CCK with a constant secretin background. Under such conditions the increase in output of pancreatic trypsin and bile salt occurred simultaneously, the dose-response curves being almost superimposable. Thus, under conditions more closely approaching normal postcibal events, the previously described differing sensitivities of the pancreas and gallbladder were not observed.     

Controlled reperfusion of cardiac grafts from non-heart-beating donors

BACKGROUND: Hearts harvested from non-heart-beating donors sustain severe injury during procurement and implantation, mandating interventions to preserve their function. We tested the hypothesis that limiting oxygen delivery during initial reperfusion of such hearts would reduce free-radical injury. METHODS: Rabbits sustained hypoxic arrest after ventilatory withdrawal, followed by 20 minutes of in vivo ischemia. Hearts were excised and reperfused with blood under conditions of high arterial oxygen tension (PaO2) (approximately 400 mm Hg), low PaO2 (approximately 60 to 70 mm Hg), high pressure (80 mm Hg), and low pressure (40 mm Hg), with or without free-radical scavenger infusion. Non-heart-beating donor groups were defined by the initial reperfusion conditions: high PaO2/ high pressure (n = 8), low PaO2/high pressure (n = 7), high PaO2/low pressure (n = 8), low PaO2/low pressure (n = 7), and high PaO2/high pressure/free-radical scavenger infusion (n = 7). RESULTS: After 45 minutes of reperfusion, low PaO2/ high pressure and high PaO2/low pressure had a significantly higher left ventricular developed pressure (63.6 +/- 5.6 and 63.1 +/- 5.6 mm Hg, respectively) than high PaO2/high pressure (40.9 +/- 4.5 mm Hg; p < 0.0000001 versus both). However, high PaO2/high pressure/free-radical scavenger infusion displayed only a trend toward improved ventricular recovery compared with high PaO2/ high pressure. CONCLUSIONS: Initially reperfusing nonbeating cardiac grafts at low PaO2 or low pressure improves recovery, but may involve mechanisms other than decreased free-radical injury.     

Simultaneous coronary artery bypass grafting and abdominal aneurysm repair decreases stay and costs

BACKGROUND: Patients with large (> or = 5.0 cm) abdominal aortic aneurysms (AAA) frequently have marked associated coronary artery disease. We hypothesized that a single operation for coronary artery bypass grafting (CABG)/AAA would provide equivalent, if not improved, patient care while decreasing postoperative length of stay and hospital costs compared with staged procedures. METHODS: Eleven patients to date have undergone a combined procedure at our institution. Ten underwent CABG followed by AAA repair, whereas one patient received an aortic valve replacement before aneurysm repair. We performed a retrospective analysis comparing the postoperative length of stay and hospital costs for this single procedure to a combined cohort of 20 randomly selected patients who either received AAA repair (n = 10) or standard CABG (n = 10) during the same time period. RESULTS: No operative mortality has been reported. There were no episodes of neurologic deficit or cardiac complication after these procedures. The postoperative length of stay was significantly decreased for the CABG/AAA group compared with the combined postoperative length of stay for the AAA plus CABG group (7.44+/-0.88 days versus 14.10+/-2.00; p = 0.012). Total hospital costs were also significantly decreased for the CABG/AAA group compared with total hospital costs for the AAA plus CABG group ($22,941+/-$1,933 versus $34,076+/-$2,534; p = 0.003). CONCLUSIONS: A single operation for coronary revascularization and AAA repair is safe and effective. Simultaneous CABG and AAA repair substantially decreases postoperative length of stay and hospital costs while avoiding possible interim aneurysm rupture and repeat anesthesia.     

Involvement of Ets, rel and Sp1-like proteins in lipopolysaccharide-mediated activation of the HIV-1 LTR in macrophages

Diagnosing acute myocardial infarction (AMI) in women is difficult since chest pain may not be a hallmark symptom. Research is needed to identify symptoms experienced by women with AMI to facilitate timely diagnosis. The purpose of this study was to identify new symptoms and their evolution experienced by women prior to diagnosis of AMI. Non-probability sampling was used to select 20 diverse women. Intensive home interviews were conducted and transcribed. Content analysis and constant comparison were used to develop nine data clusters: Location of Pain; Intensity of Pain/Sensations; Cardiovascular/Temperature Changes; Respiratory Sensations; Gastrointestinal Symptoms; Emotions; Hand and Arm Sensations; Neurological/Vision Changes; and Fatigue. Some women progressed to AMI in minutes while others had symptoms for weeks. Findings should increase awareness of women's symptoms of AMI. Further research is needed with a larger sample.