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At least 829 records · Page 46Linked to original sources
PubMed1995

Transient atrioventricular block after release of aortic cross-clamp.

To determine the incidence of atrioventricular (A-V) block, 86 patients, aged 58.9 +/- 10.4 yr, undergoing elective coronary artery bypass grafting (CABG) during aortic cross-clamping (ACC) and cold potassium cardioplegia were investigated. The incidence and duration of complete A-V block after release of the aortic cross-clamp was monitored. Twenty-four percent of the patients developed complete A-V block that required temporary pacing for a mean time of 66 +/- 39 min. The volume of cardioplegia used was not significantly different between the patients who developed A-V block and the patients who had no block. The serum potassium level at the time of release of the aortic cross-clamp was within the normal range in both groups. Six factors were correlated with the development of A-V block: old age, preparation by a combination of beta-adrenergic blockers and calcium channel blockers, preoperative bradycardia, the number of vessels grafted, as well as the duration of ACC. Also, the serum potassium level at the time of release of the aortic cross-clamp was significantly higher in the patients who developed A-V block. The high incidence of A-V block in elderly patients undergoing multiple coronary vessel grafting during a prolonged ACC time suggests that suboptimal myocardial preservation may be the main predisposing factor.

Aged↗
PubMed2001

The effects of FK506 on neurologic and histopathologic outcome after transient spinal cord ischemia induced by aortic cross-clamping in rats.

UNLABELLED: Spinal cord injury is a devastating complication of thoracoabdominal aortic surgery. We investigated the effect of the immunosuppressant FK506, a macrolide antibiotic demonstrated to have neuroprotective effects in cerebral ischemia models, in a rat model of transient spinal cord ischemia. Spinal cord ischemia was induced in anesthetized rats by using direct aortic arch plus left subclavian artery cross-clamping through a limited thoracotomy. Experimental groups were as follows: sham-operation; control, receiving only vehicle; FK506 A, receiving FK506 (1 mg/kg IV) before clamping; and FK506 B, receiving FK506 (1 mg/kg IV) at the onset of reperfusion. Neurologic status was assessed at 24 h and then daily up to 96 h with a 0 to 6 scale (0, normal function; 6, severe paraplegia). Rats were randomly killed at 24, 48, or 96 h, and spinal cords were harvested for histopathology. Physiologic variables did not differ significantly among experimental groups. All control rats suffered severe and definitive paraplegia. FK506-treated rats had significantly better neurologic outcome compared with control. Histopathologic analysis disclosed severe injury in the lumbar gray matter of all control rats, whereas most FK506-treated rats had less injury. These data suggest that FK506 can improve neurologic recovery and attenuate spinal cord injury induced by transient thoracic aortic cross-clamping. IMPLICATIONS: A single dose-injection of the immunosuppressant FK506 significantly improved neurologic outcome and attenuated spinal cord injury induced by transient thoracic aortic cross-clamping in the rat.

Animals↗
PubMed2002

Vertical mammaplasty with a clamp technique.

The vertical mammaplasty with a clamp technique is a personal adaptation of the clamp technique that leaves a single vertical scar in addition to the periareolar scar. This technique uses a superior pedicle from the dermal vault technique. There is no need for preoperative markings. The glandular tissue is removed with constant reference to the breast base. The skin is excised around a new clamp, which leaves only a vertical scar. This retrospective study includes 100 patients operated between 1996 and 2000. A total of 96% of the patients have been happy with the final cosmetic result. The best results were obtained when breast ptosis and moderate hypertrophy were present. The complication rate was 4%. This technique is as reliable as other procedures using the superior flap technique. A vertical scar is obtained by using a new clamp that allows a perfect match of the gland to its cutaneous cover. It is also a fast technique to perform (75 minutes).

Adolescent↗
PubMed1981

Temporary incomplete ischemia of the legs caused by aortic clamping in man: improvement of skeletal muscle metabolism by low molecular dextran.

Temporary infrarenal clamping of the aorta during reconstructive surgery induces incomplete ischemia of the leg muscle. After release of the clamp, severe muscle metabolic derangement with loss of high-energy phosphate compounds has been observed, indicating a dysfunction or damage of the muscle cells. In six patients operated on for occlusive aortoiliac disease, low-molecular-weight dextran (LMWD) was peroperatively administered for optimal volume loading and prevention of clotting. No heparin was used. Before, during and after the clamping period the central hemodynamics were monitored, and glycogen, glucose, lactate, pyruvate, phosphocreatine (PCr), creatine (Cr), ATP, ADP and AMP content in the thigh muscle were analyzed using enzymatic fluorometric techniques. Even though ischemia developed during the occlusion, no decline in the adenylate (ATP + ADP + AMP) or creatine (PCr + Cr) pools occurred after the clamp was released, and the energy charge of the adenine nucleotides remained unchanged. It is suggested that LMDX prevents rheologic changes impairing the microcirculation during and after the ischemic period, and thereby improves oxygenation of the muscle tissue upon reperfusion.

Adenosine Diphosphate↗
PubMed1999

Continuous versus intermittent portal triad clamping for liver resection: a controlled study.

OBJECTIVE: The authors compared the intra- and postoperative course of patients undergoing liver resections under continuous pedicular clamping (CPC) or intermittent pedicular clamping (IPC). SUMMARY BACKGROUND DATA: Reduced blood loss during liver resection is achieved by pedicular clamping. There is controversy about the benefits of IPC over CPC in humans in terms of hepatocellular injury and blood loss control in normal and abnormal liver parenchyma. METHODS: Eighty-six patients undergoing liver resections were included in a prospective randomized study comparing the intra- and postoperative course under CPC (n = 42) or IPC (n = 44) with periods of 15 minutes of clamping and 5 minutes of unclamping. The data were further analyzed according to the presence (steatosis >20% and chronic liver disease) or absence of abnormal liver parenchyma. RESULTS: The two groups of patients were similar in terms of age, sex, nature of the liver tumors, results of preoperative assessment, proportion of patients undergoing major or minor hepatectomy, and nature of nontumorous liver parenchyma. Intraoperative blood loss during liver transsection was significantly higher in the IPC group. In the CPC group, postoperative liver enzymes and serum bilirubin levels were significantly higher in the subgroup of patients with abnormal liver parenchyma. Major postoperative deterioration of liver function occurred in four patients with abnormal liver parenchyma, with two postoperative deaths. All of them were in the CPC group. CONCLUSIONS: This clinical controlled study clearly demonstrated the better parenchymal tolerance to IPC over CPC, especially in patients with abnormal liver parenchyma.

Alanine Transaminase↗
PubMedDate not supplied

Control of severe hemorrhage using C-clamp and pelvic packing in multiply injured patients with pelvic ring disruption.

OBJECTIVES: Evaluation of diagnostic and therapeutic workup in multiply injured patients with pelvic ring disruption and hemorrhagic shock. DESIGN: Prospective study. PATIENTS: Twenty consecutive multiply injured patients (ISS: 41.2 +/- 15.3 points) with pelvic ring disruption and hemorrhagic shock. INTERVENTION: A C-clamp was used for primary stabilization of the pelvic ring instability. In patients with persistent or massive hemorrhage, laparotomy and pelvic packing were performed. Consecutive measurements of blood lactate levels during the early period after injury. MAIN OUTCOME MEASUREMENTS: Lactate, mortality. RESULTS: A C-clamp was applied in all patients within 57.4 +/- 30.6 minutes of arrival. Fourteen patients underwent laparotomy with pelvic packing for control of hemorrhage, three patients additional resuscitation thoracotomy (aortic clamping: n = 2). Four patients died of exsanguinating hemorrhage during the first 5.4 +/- 3.3 hours from arrival, one patient because of septic multi-organ failure twenty-three days after injury (total mortality: 5/20; 25 percent). Lactate levels at admission were elevated in all patients (5.1 +/- 2.6 mmol/l). Increased blood lactate levels (4.8 +/- 1.7 mmol/l) (+71 percent; p < 0.05) were observed in survivors undergoing laparotomy compared with survivors without laparotomy (2.8 +/- 1.1 mmol/l). In contrast, hemoglobin (7.0 +/- 2.6 g/dl versus 7.9 +/- 2.2 g/dl) and hematocrit (21.4 +/- 6.4 percent versus 23.2 +/- 6.8 percent) were similar in both groups. In patients who died during the first hours after admission, lactate levels were elevated (8.6 +/- 2.5 mmol/l) compared with survivors (4.2 +/- 1.8 mmol/l) and increased further. CONCLUSIONS: Sequential measurements of blood lactate levels during the early period after injury may provide a more rapid and reliable estimation of true severity of hemorrhage than routinely used parameters. Pelvic packing in addition to pelvic ring fixation with a C-clamp allows for effective control of severe hemorrhage in multiply injured patients with pelvic ring disruption.

Adolescent↗
PubMed1998

Preoperative volume expansion improves tolerance to carotid artery cross-clamping during endarterectomy.

OBJECTIVE: The benefit of carotid endarterectomy for carotid artery stenosis relates to both appropriate patient selection and careful surgical technique. Critical to the latter is the ability to afford intraoperative neuroprotection during carotid cross-clamping, although the optimal strategy to assure this protection remains debated. This report describes the impact of adding preoperative colloid volume expansion to a surgical algorithm that includes electroencephalographic (EEG) monitoring and barbiturate-induced burst suppression for EEG lateralization refractory to hypertension. METHODS: The incidence of ischemic EEG change during carotid cross-clamping was observed. The results of an initial series of patients (n = 45) reported before incorporation of volume expansion were compared with the results of the current series (n = 155) of carotid endarterectomies, which included preoperative volume expansion with 6% hetastarch (500 or 1000 cc). RESULTS: With preoperative volume expansion, there was a 40% decrease in the incidence of EEG lateralization during carotid cross-clamping (17.4 versus 28.9%, P < 0.05) and a 63% decrease in the EEG lateralization refractory to induced hypertension (5.8 versus 15.6%, P < 0.05). The combined perioperative stroke and death rate was 1.3%. CONCLUSION: These results support the use of preoperative colloid volume expansion in carotid endarterectomy as a means of increasing the cerebral tolerance to carotid cross-clamping.

Adjuvants, Anesthesia↗
PubMed2001

The contact lens and myopia progression (CLAMP) study: design and baseline data.

BACKGROUND: Although previous contact lens myopia control studies indicate that rigid contact lenses slow the progression of myopia in children, they have all suffered from limitations that challenge the significance of their results. The Contact Lens and Myopia Progression (CLAMP) Study addresses the limitations of previous studies and attempts to correct them by implementing alternative Study designs. The CLAMP study also measures all the ocular components to examine the potential mechanism of treatment effect. METHODS: Eligible children were fitted with rigid gas-permeable contact lenses and enrolled in a run-in period to determine whether they were able to adapt to rigid contact lens wear. Subjects who successfully completed the run-in period were randomly assigned to wear rigid contact lenses or soft contact lenses for the remainder of the 3-year study. The primary outcome measure will be the 3-year change in cycloplegic autorefraction; the secondary outcome measures will include the 3-year change in axial length, peripheral autorefraction, crystalline lens curvatures, corneal curvature and thickness, accommodation, and intraocular pressure, which are being measured annually. RESULTS: We examined 148 eligible subjects who participated in the run-in period. Of the 148 eligible subjects, 116 (78.4%) were able to adapt to rigid contact lens wear and were enrolled in the CLAMP Study. The mean age of the participants at the baseline visit was 10.5 years, and 59.5% were girls. At the randomization visit, the mean (+/-SD) spherical equivalent refractive error in the right eye was -2.09 +/- 0.89 D, the mean central curvature of the right cornea by videokeratography was 44.5 +/- 1.3 D, and the mean axial length of the right eye was 24.13 +/- 0.71 mm. CONCLUSIONS: Four of five children aged 8- to 11-years-old were able to adapt to rigid gas-permeable contact lens wear. The CLAMP Study aims to further clarify the effect of rigid gas-permeable contact lenses on myopia progression in children.

Astigmatism↗
PubMed2006

D-lactate is not a reliable marker of gut ischemia-reperfusion in a rat model of supraceliac aortic clamping.

OBJECTIVE: D-lactate is the dextrorotatory form of L-lactate. L-lactate is the isomer routinely tested in clinical practice to assess cell hypoxemia. D-lactate has been recently proposed as a specific marker of gut ischemia-reperfusion (IR), particularly after surgery for ruptured aortic aneurysms. We sought to assess D-lactate as a reliable marker of gut IR in a rat model of supraceliac aortic clamping. DESIGN: Prospective, randomized trial. SETTING: Animal research center. SUBJECTS: Male Wistar rats. INTERVENTIONS: After general anesthesia, rats were randomized into two groups (n = 8 in each). The IR group underwent a laparotomy, aortic clamping for 40 mins, and 1 hr of reperfusion. The control group underwent the same procedure, except for aortic clamping. MEASUREMENTS AND MAIN RESULTS: The following variables were tested after 1 hr of reperfusion (IR group) or after the equivalent time (control group): 1) tissue and cell insult via ileum morphometry and electron microscopy, serum glutamic transaminases (serum glutamic-oxaloacetic transaminase and serum glutamic-pyruvic transaminase), pH, and L-lactate; 2) systemic inflammatory response via tumor necrosis factor-alpha; and 3) D-lactate levels. After IR, mucous membrane thickness and villi height decreased significantly, respectively by 30% and 45%, and electron-microscopic examination showed typical IR mucous membrane cell insult. IR also caused lactic acidosis (pH = 7.16 +/- 0.05 vs. 7.31 +/- 0.02, p < .01; L-lactate = 7.1 +/- 1.6 vs. 1.6 +/- 0.4 mmol/L, p = .001) and increased blood levels of transaminases. Concurrently, the inflammatory response was characterized by an increase in tumor necrosis factor-alpha (213 +/- 129 vs. 47 +/- 32 pg/mL, p < .05). However, blood levels of D-lactate never increased after IR. CONCLUSIONS: D-lactate is not a reliable marker of gut IR in our model of supraceliac aortic clamping in rats.

Animals↗
PubMed2005

Potassium-titanyl-phosphate laser laparoscopic partial nephrectomy without hilar clamping in the survival calf model.

PURPOSE: Laparoscopic partial nephrectomy (LPN) with hilar clamping represents the various challenges associated with warm ischemia. We tested the feasibility, and acute and chronic outcomes of LPN using a potassium-titanyl-phosphate (KTP) laser without vascular hilar clamping in the survival calf model. MATERIALS AND METHODS: Six Jersey calves weighing 76 to 94 kg underwent a total of 12 staged bilateral transperitoneal laser LPNs of the mid/lower pole using an 80 W KTP laser, including left kidney chronic LPN with 1-month followup in 6 and right kidney acute LPN with immediate sacrifice in 6. Two techniques (ablative vaporization in 5 subjects and wedge resection in 7) were evaluated. Renal parenchymal resection and hemostasis were achieved only with the laser without any adjunctive hemostatic sutures or bioadhesives. Retrograde pyelography, renal arteriography and histological analyses were performed. RESULTS: All 12 procedures were successful performed laparoscopically without open conversion and 11 (92%) were done without hilar clamping. Mean total operative time was 2.9 hours (range 1.5 to 5) and mean blood loss was 119 cc (range 25 to 300). Mean lasing time was 56 minutes (range 20 to 100) with an average energy use of 54 kJ. Mean preoperative and postoperative hemoglobin (10.38 and 10.52 gm/dl) and serum creatinine (0.46 and 0.4 gm/dl, respectively) were similar. At 1-month followup there was no evidence of urinary leakage or arteriovenous fistula. CONCLUSIONS: This initial study of laparoscopic KTP laser partial nephrectomy without hilar clamping confirms its technical feasibility in most cases and good short-term outcomes. This success of laser LPN in the robust survival calf model with its human-sized kidney holds promise for future clinical application.

Animals↗
PubMed1987

Cooling prevents ischaemic testicular damage after spermatic cord clamping in rats.

A controlled trial was conducted on four groups of seven rats to evaluate any beneficial effect of cooling to 15 degrees C on testicular ischaemia induced by clamping of the spermatic cord for 2, 4, 6 or 8 h. At operation the microscopic appearance of the testes on unclamping was a poor guide to ultimate viability, whereas by the third day macroscopic and microscopic appearances concurred. When killed on the third day, testicular histology demonstrated that increasing periods of clamping led to gross ischaemia and infarction when testes were maintained at 37 degrees C, and this was reduced greatly by testicular cooling. For each period of clamping, maintenance of spermatogenesis, expressed in terms of Johnsen's histological scores, was significant (P less than 0.01), being 2 (37 degrees C) vs 5.3 (15 degrees C) for 8-h clamping. It is proposed that testicular cooling should be used during autotransplantation of testes in humans.

Animals↗
PubMed2006

Competition of bacteriophage polypeptides with native replicase proteins for binding to the DNA sliding clamp reveals a novel mechanism for DNA replication arrest in Staphylococcus aureus.

Bacteriophages have evolved specific mechanisms that redirect bacterial metabolic pathways to the bacteriophage reproduction cycle. In this study, we characterized the bactericidal mechanism of two polypeptides from bacteriophages Twort and G1 that target the DNA sliding clamp of Staphylococcus aureus. The DNA sliding clamp, which tethers DNA polymerase to its template and thereby confers processivity upon the enzyme, was found to be essential for the viability of S. aureus. Expression of polypeptides TwortORF168 and G1ORF240 in S. aureus selectively inhibited DNA replication which in turn resulted in cell death. Both polypeptides specifically inhibited the S. aureus DNA replicase that was reconstituted in vitro but not the corresponding replicase of Streptococcus pyogenes. We demonstrated that inhibition of DNA synthesis is multifaceted and occurs via binding the DNA sliding clamp: TwortORF168 and G1ORF240 bound tightly to the DNA sliding clamp and prevented both its loading onto DNA and its interaction with DNA polymerase C. These results elucidate the impact of bacteriophage polypeptide expression upon DNA replication in the growing cell.

Amino Acid Sequence↗
PubMed1992

Diurnal rhythm of phosphorylation of rat liver acetyl-CoA carboxylase by the AMP-activated protein kinase, demonstrated using freeze-clamping. Effects of high fat diets.

1. Acetyl-CoA carboxylase was purified to homogeneity, in the presence of protein phosphatase inhibitors, from rat liver sampled without freeze-clamping. The enzyme was in a highly phosphorylated state (4.8 mol/subunit) of low specific activity, and could be dramatically reactivated by treatment with protein phosphatase-2A. Amino acid sequencing and fast-atom-bombardment mass spectrometry showed that the enzyme was phosphorylated in Ser79, Ser1200 and Ser1215, the three sites known to be phosphorylated in cell-free assays by the AMP-activated protein kinase. 2. The inactive enzyme could also be completely reactivated using a limited treatment with trypsin, which removes the N-terminal segment containing Ser79 and reduces the phosphate content to 3.5 mol/subunit. These results strengthen previous findings that it is phosphorylation at Ser79 by the AMP-activated protein kinase that is responsible for the inactivation, and not the phosphorylation of the 220-kDa core fragment (which contains Ser1200 and Ser1215). 3. Analysis of the phosphorylation state of Ser79 in acetyl-CoA carboxylase from rat liver showed that phosphorylation occurs post mortem if freeze-clamping is not used. The higher phosphorylation observed in extracts made without freeze-clamping correlates with a large increase in AMP and decrease in ATP (presumably caused by hypoxia during removal of the liver), and with increased activity of the AMP-activated protein kinase. These results provide a rational explanation for the post mortem phosphorylation events, and re-emphasize the point that rapid cooling of cells and tissues is essential when measuring the expressed activity of acetyl-CoA carboxylase (as well as 3-hydroxy-3-methylglutaryl-CoA reductase). 4. Using the freeze-clamping procedure, the ratio of 'expressed' activity (measured in the presence of protein phosphatase inhibitors) to 'total' activity (measured after complete dephosphorylation) of rat liver acetyl-CoA carboxylase showed a marked diurnal rhythm, changing from 50% in the active form in the middle of the dark period to less than 10% active in the middle of the light period. The very low activity in the light period was associated with a high level of phosphorylation in Ser79. This diurnal rhythm is very similar to that previously described for the phosphorylation of 3-hydroxy-3-methylglutaryl-CoA reductase, another substrate for the AMP-activated protein kinase. Neither the activity of the AMP-activated protein kinase nor the content of AMP, ADP or ATP changed between the dark or light periods.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetyl-CoA Carboxylase↗
PubMed1999

Oxygen-dependent K+ influxes in Mg2+-clamped equine red blood cells.

1. Cl--dependent K+ (86Rb+) influxes were measured in oxygenated and deoxygenated equine red blood cells, whose free [Mg2+]i had been clamped, to examine the effect on O2 dependency of the K+-Cl- cotransporter. 2. Total [Mg2+]i was 2.55 +/- 0.07 mM (mean +/- s.e.m. , n = 6). Free [Mg2+]i was estimated at 0.45 +/- 0.04 and 0.68 +/- 0. 03 mM (mean +/- s.e.m., n = 4) in oxygenated and deoxygenated red cells, respectively. 3. K+-Cl- cotransport was minimal in deoxygenated cells but substantial in oxygenated ones. Cl--dependent K+ influx, inhibited by calyculin A, consistent with mediation via the K+-Cl- cotransporter, was revealed by depleting deoxygenated cells of Mg2+. 4. Decreasing [Mg2+]i stimulated K+ influx, and increasing [Mg2+]i inhibited it, in both oxygenated and deoxygenated red cells. When free [Mg2+]i was clamped, Cl--dependent K+ influxes were always greater in oxygenated cells than in deoxygenated ones, and changes in free [Mg2+]i of the magnitude occurring during oxygenation-deoxygenation cycles had a minimal effect. Physiological fluctuations in free [Mg2+]i are unlikely to provide the primary link coupling activity of the K+-Cl- cotransporter with O2 tension. 5. Volume and H+ ion sensitivity of K+ influx in Mg2+-clamped red cells were increased in O2 compared with those in deoxygenated cells at the same free [Mg2+]i, by about 6- and 2-fold, respectively, but again these features were not responsible for the higher fluxes in oxygenated cells. 6. Regulation of the K+-Cl- cotransporter by O2 is very similar in equine, sheep and in normal human (HbA) red cells, but altered in human sickle cells. Present results imply that, as in sheep red cells, O2 dependence of K+-Cl- cotransport in equine red cells is not mediated via changes in free [Mg2+]i and that cotransport in Mg2+-clamped red cells is still stimulated by O2. This behaviour is contrary to that reported for human sickle (HbS) cells.

Animals↗
PubMed2006

First clinical experience with the air purge control and electrical remote-controlled tubing clamp in mini bypass.

Most mini bypass systems do not contain a venous and cardiotomy reservoir in the cardiopulmonary bypass (CPB) circuit and lack the capability to remove venous air. In conjunction with the manufacturer the air purge control system, a system which automatically removes air that is captured in a venous bubble trap, has been developed. This system is combined with an electrical remote clamp, which automatically clamps the arterial line in case air leaves the bubble trap. Twenty consecutive patients undergoing surgery with CPB were included in this clinical validation. Venous air was removed by the air purge control during bypass. The electrical remote clamp was never activated by the system, confirming that the air purge control adequately removed venous air during these cases. The air purge control, in conjunction with the electrical remote clamp, is a valuable safety feature in mini bypass, enhancing patient safety and user friendliness while providing a level of safety equivalent to those of conventional bypass systems.

Aged↗
PubMed2006

Mechanical evaluation of two crimp clamp systems for extracapsular stabilization of the cranial cruciate ligament-deficient canine stifle.

OBJECTIVE: To compare the mechanical properties and interoperator variabilities of 2 crimp clamp systems for extracapsular, fabello-tibial, nylon loop stabilization of the cranial cruciate ligament-deficient stifle in dogs. STUDY DESIGN: In vitro mechanical testing. METHODS: Three operators with different grip strengths each secured 20 standardized nylon loops using stainless-steel crimp clamps: 10 using a Veterinary Instrumentation system (45 kg [100 lb] test nylon leader line, 12 mm crimp clamps) and 10 using a Securos system (36 kg [80 lb] test nylon leader line, 36 kg [80 lb] crimp clamps). Loops were tensile loaded to failure in a materials testing machine. RESULTS: Mean ultimate load and mean stiffness were significantly higher for the Securos (336.9 N, 60.6 N/mm) than for the Veterinary Instrumentation system (113.8 N, 37.0 N/mm). For both systems, ultimate load was subject to interoperator variability. CONCLUSIONS: The Securos loops were significantly stronger and stiffer than the Veterinary Instrumentation loops for all operators, but significant differences between operators for ultimate load existed for both systems. CLINICAL RELEVANCE: Securos fabello-tibial sutures will withstand greater loads than Veterinary Instrumentation sutures and this is particularly true for sutures created by surgeons with reduced grip strength. It may be necessary to use more than 1 Veterinary Instrumentation suture to match the ultimate load and stiffness of a Securos suture.

Animals↗
PubMed1977

Effect of early and late cord clamping on the systolic time intervals of the newborn infant.

The effect of early and late cord clamping on the left ventricular performance of the newborn infant was assessed by measuring the systolic time intervals from the indirect carotid pulse tracings and simultaneous phonocardiogram and electrocardiogram. The study was performed in 13 normal, full-term infants sequentially at 20-105 min, 6-6 1/2 hrs, and 24-27 hrs of age. The umbilical cords were clamped early in 7 (E.C.) and clamped late in 6 infants (L.C.). The ratio of the pre-ejection period (PEP) to the left ventricular ejection time (LVET) was found to be significantly higher in the L.C. infants (mean +/- S.E., 0.400 +/- 0.18, 0.433 +/- 0.018, 0.410 +/- 0.021) compared with those of the E.C. (0.334 +/- 0.010, 0.347 +/- 0.009, 0.361 +/- 0.007) with p values of less than 0.01, less than 0.005 and less than 0.05, respectively in the three examination periods. The higher PEP/LVET ratios in the L.C. infants were mainly attributable to a prolongation of the PEP. It is suggested that late cord clamping, by allowing a sizable placental transfusion, appeared to affect adversely the left ventricular performance of the neonate. Furthermore, it is suggested that in evaluating systolic time intervals of the neonate during the first days of life, the volumic state or status of placental transfusion should be taken into consideration as a determinant.

Female↗
PubMed1977

Glial changes in pigs with porto-caval anastomosis and temporary or total hepatic artery clamping.

The number and size of astrocyte, oligodendrocyte, and neurone nuclie were determined in cortex and corpus striatum (putamen) of pigs with porto-caval anastomosis (PCA) and total or temporary clamping of the hepatic artery. Animals with PCA and total clamping became comatose and died on average 18 1/2 hours postoperatively. Their brains showed slight oedema but no changes in the glial and neurone nuclear numbers. Animals with PCA and temporary clamping of the hepatic artery (30-60 min.) all survived without clinical symptoms of encephalopathy. However, the brains showed vacuolization of the deeper cortical layers, diffuse occurrence of Alzheimer type II astrocytes, and the counts revealed an increased number of astrocytic nuclei. The total number of glial cells decreased due to loss of oligodendrocytes, but the number of neurones was unchanged. The findings indicate that the neuropathological changes after PCA and temporary hepatic artery clamping are concerned primarily with changes of the glial cells.

Animals↗