Expected gain and status number following restricted individual and combined-index selection

Imposition of restrictions on number of individuals selected from a family and number of families from which superior individuals are selected could markedly alter the consequences of individual and combined-index selection. Predicted genetic gain and diversity measured as status number following selection were studied to draw general conclusions. Selection and its prediction were applied to two sets of real-life data. Theoretical prediction gave results close to those from factual selection. Gain and status number varied with initial family number and size, sib type, heritability, selection proportion, restriction type and intensity, and selection criteria. Proper restriction on the number of individuals selected can control the reduction of status number to an acceptable level, particularly when breeding values are used as the selection criterion. Restriction on the number of families selected would effectively improve the gain efficiency of selection based on phenotypic values. Choosing combinations of both restrictions might produce higher gain without the loss of status number. Given constant population size, family number should be large enough to ensure that restricted selection will yield higher gain and status number.

Construction of a framework map in Pinus contorta subsp. latifolia using random amplified polymorphic DNA markers

We report on the construction of the first random amplified polymorphic DNA (RAPD) framework map in Pinus contorta subsp. latifolia. Genomic DNA of haploid megagametophytes from 90 open-pollinated seeds originating from a single tree were amplified with 840 random decamer oligonucleotide primers by the polymerase chain reaction. Three-hundred twenty-eight RAPD markers with fragment sizes that ranged between 260 and 3080 base pairs were found segregating at 110 random decamer oligonucleotide primers. Of these 328 RAPD markers, 148 were mapped to 16 framework linkage groups and 77 were mapped as accessory markers onto the framework linkage groups, on a support interval of minimal LOD score of 3. The 16 framework maps cover a distance of 2287 cM. The estimate of genome size was 2407 cM with a 95% confidence interval of 2304-2459 cM.

Random amplified polymorphic DNA diversity of marginal and central populations in Pinus contorta subsp. latifolia

Fifteen populations of lodgepole pine (Pinus contorta subsp. latifolia) were surveyed for diversity across 52 random amplified polymorphic DNAs (RAPDs). The objective was to compare single-locus and multilocus structures in four marginal, three intermediate, and eight central populations. Single-locus estimates indicated average observed and expected heterozygosity to be 0.19 and 0.17, respectively. When these estimates were split into population categories, a clear trend of increasing diversity was detected in the direction of marginal to central populations. F-statistics indicated an excess of heterozygotes, with F(IS) ranging from -0.08 for marginal populations to -0.15 for central populations and averaging -0.12 over 15 populations. The estimates of F(ST) decreased towards the margins of the species range, indicating increased population differentiation. Forty-nine of 52 RAPDs tested neutral in the Ewens-Watterson analysis. Multilocus analysis showed significant two-locus and high-order gametic disequilibria in all 15 populations. The most prominent components of the two-locus analysis were the variance of disequilibrium (VD, 46.2%) and the multilocus Wahlund effect (31.9%). This high value for VD indicated that founder effects could explain much of the observed multilocus associations. When analyzed by population categories, the VD showed a decreasing trend indicating that variation due to founder effects was more prominent in marginal populations. The two-locus Wahlund effect (WC) that is characteristic of strong population subdivision was highest in the central populations. This indicated significant levels of gene flow between populations with different allelic combinations.

Temporary hearing impairment after general anesthesia--a case report

The incidence of hearing impairment after anesthesia is rare. We report a case who received left total knee and hip replacement and developed severe hearing impairment of the left ear after general anesthesia. Examination of the left ear by an otolaryngologist showed that there was no noticeable abnormality. The hearing acuity recovered gradually and returned to normal 3 days later. The use of nitrous oxide during anesthesia was incriminated as the possible cause.

Acute fatal vasoplegia and asystole induced by intravenous amiodarone after cardiopulmonary bypass in a patient with preoperative cardiogenic shock

Single dose intravenous amiodarone has been widely used and shown to be effective to treat supraventricular and ventricular arrhythemias in cardiac surgery. We, herein, report a 60-year-old female patient, sustaining cardiogenic shock in the course of percutaneous transluminal coronary angioplasty (PTCA) for unstable angina unrelieved by medication including nitroglycerin, succumbed to a life-saving emergent coronary artery bypass grafting (CABG) operation at the end of cardiopulmonary bypass (CPB) following a 180 mg bolus dose of amiodarone (3 mg/kg) directed at the ventricular arrhythmias, triggered by protamine and unresponsive to lidocaine treatment. Amiodaroneinduced asystole and vasoplegia were thought to be the causation of the failure of resuscitation. The causes of the development of these complications, the potential hazards of its use and the management relative to the consequential complications are reviewed and discussed.

Optimal diversity-dependent contributions of genotypes to mixtures

Deployment of genotypes to a production population decisively depends on the measure of diversity, a consideration that parallels genetic gain in the management of genotype mixtures. Optimal diversity-dependent deployment has been developed in this study for a family of diversity indices in the genetical and ecological context. The optimal solution at given diversity was expressed as the relationship between genotype contributions and their genetic performances, which maximized genetic gain. Numerical calculations were performed by using genotypes generated from normal order statistics. An optimal deployment in one situation could be nonoptimum in another. Classical uniform deployment, where superior genotypes equally contribute to the mixtures, was the limit of optimal deployment. Comparisons were made between optimal and uniform deployment and between optimal and nonoptimal deployment where genotypes contributed proportionally to the mixtures in accordance to their genetic superiority. The superiority in gain of optimal deployment over that of uniform deployment increased as the difference between the diversity measure under optimal deployment and the contributing number (N) of genotypes under uniform deployment became large and as the diversity measure and N under optimal deployment increased. The superiority over nonoptimal deployment increased rapidly at low diversity, reaching a maximum somewhere at diversity between 1 and N. Scale of superiority depended on the similitude between optimum and nonoptimum deployment; the larger the distinctiveness, the greater the superiority.

Low dose ketamine and midazolam as supplements for spinal anesthesia

BACKGROUND

Low dose ketamine and midazolam together were used as supplements during spinal anesthesia to provide analgesia for insertion of spinal needle and intraoperative sedation.

METHODS

Two regimens of drug combination (ketamine 0.5 mg/kg and midazolam 0.05 mg/kg in group I, n = 30; ketamine 0.5 mg/kg and midazolam 0.1 mg/kg in group II, n = 30) were administered intravenously before proceeding lumbar puncture.

RESULTS

Systolic and diastolic arterial blood pressure, heart rate, and arterial oxygen saturation did not change significantly before and after the administration of drugs. Most patients in both groups showed good analgesic response to the lumbar puncture. The medications induced a brief unconsciousness (4.1 min in group I; 8.5 min in group II). The time from drug administration to recovery of mental orientation was 8.8 min in group I and 15.1 min in group II. The regimens also provided intraoperative sedation. Patients in group II appeared to be more depressed than group I in the first 30 min. None of the patients had significant respiratory disturbance, involuntary movement, or recall to spinal puncture. There were 7 patients in group I and 4 patients in group II who experienced dreaming.

CONCLUSIONS

The use of low dose ketamine together with midazolam as supplement for spinal anesthesia is helpful in anesthetic practice.

The maternal and fetal effects of the addition of sufentanil to 0.5% spinal bupivacaine for cesarean delivery

BACKGROUND

Opioid added to local anesthetic for spinal anesthesia was first introduced into clinical practice in 1979 with intrathecal morphine as a forerunner. As morphine is water soluble and has prolonged action, late respiratory depression following spinal anesthesia is not infrequent and is the most serious complication that causes our concern. Sufentanil which is more hydrophobic than morphine also with shorter duration of action and quicker onset when injected into the subarchnoid space could be more effective and a safer drug as an adjuvant to local anesthetic in spinal anesthesia.

METHODS

Forty-one parturients who had given consent to spinal anesthesia for Cesarean delivery, were anesthetized with 12.5 mg of 0.5% bupivacaine alone or in combination with 10 micrograms sufentanil in a randomized double blind manner. They were assigned either to C group (Control group) in which nothing is added to the local anesthetic and S group (Study group) in which sufentanil was added to the local anesthetic.

RESULTS

Perioperatively, hypotension occurred more in S group (17 against 11) but chest discomfort was less (3 against 7). Within 3 h after anesthesia 3 out of 19 parturients in S group requested analgesics but almost all parturients in C group did so.

CONCLUSIONS

The addition of intrathecal sufentanil to 0.5% bupivacaine for spinal anesthesia improved perioperative discomfort and significantly reduced the demand of post-operative analgesia but on the other hands, it tended to increase perioperative hypotension and cause mild pruritus.

Shortening and superlon-wrapping the downstream tube can increase the useful range of the blood warmer

BACKGROUND

Hypothermia occurs frequently in clinical anesthesia. Many apparatus were introduced to keep intravenous fluid warm. But at low to medium flow rates little effects have been achieved because of heat lost along the tube. Superlon, an industrial heat-preserving material widely used in air conditioning to prevent temperature change, has never been used in the blood warmer.

METHODS

The study was performed in three groups group I using standard (120 cm) unwrapped tube (Animac AM-4 set), group II using a shortened downstream tube (60 cm), and group III using the downstream tube which was further wrapped with superlon (Super LTD). The blood warmer used was identical in all 3 groups. We recorded the fluid temperatures at different points downstream at various flow rates. The values were then compared among groups.

RESULTS

The fluid temperatures before entering the warmer were around 20 degrees C and 37 degrees C at the 2 cm post-warmer points at various flow rates. The end point temperatures rose with flow rates and were the highest in group III and lowest in group I at each flow rate (p < 0.01). In group III the temperature could be kept above 32 degrees C at a very low flow rate (150 ml/h) and above 35 degrees C at 300 ml/h. In group I, 1,000 to 2,000 ml/h were needed to keep the same temperature.

CONCLUSIONS

These refinements increase the useful range of the Animac AM-4 warmer and make it useful in pediatric rapid fluid resuscitation and current fluid management. Moreover, they are easy to set up, inexpensive, and can be applied to any kind of blood warmers.

[Pulmonary and paradoxical embolism after total knee replacement--a case report]

Pneumatic tourniquet and hone cement are often applied in orthopaedic surgery. In lower limb surgery, deep vein thrombosis may occur after release of tourniquet, causing embolism of lungs and vital organs. Paradoxical embolism may develop if the patients present extracardiac or intracardiac right to left shunt, such as atrial septum defect, etc. A 60-year-old female patient suffered from osteoarthritis of both knees was admitted for total knee replacement (TKR). Pneumatic tourniquet was inflated on the operated leg for the orthopaedic surgery which lasted for 2h. Dyspnea, sinus tachycardia and abdominal pain were noted after TKR. Blood gases analysis showed arterial hypoxemia and respiratory alkalosis. Chest X-ray revealed diffused bilateral pulmonary infiltration, pulmonary trunk engorgement, and decreased lung markings. Two days after TKR under the impression of peritonitis, she received exploratory laparotomy in which ischemic bowel and gall bladder were found. Pulmonary and paradoxical embolism were diagnosed, both of which were the well-known complications of TKR with tourniquet and bone cement application. The patient finally succumbed because of multiple organ failures.

A comparison of isozyme and quantitative genetic variation in Pinus contorta ssp. latifolia by FST

We employed F-statistics to analyze quantitative and isozyme variation among five populations of Pinus contorta ssp. latifolia, a wind-pollinated outcrossing conifer with wide and continuous distribution in west North America. Estimates of population differentiation (FST) for six quantitative traits were compared with the overall estimate of the differentiation (F*ST) from 19 isozymes that tested neutral to examine whether similar evolutionary processes were involved in morphological and isozyme differentiation. While the FST estimates for specific gravity, stem diameter, stem height and branch length were significantly greater than the F*ST estimate, as judged from the 95% confidence intervals by bootstrapping, the FST estimates for branch angle and branch diameter were indistinguishable from the F*ST estimate. Differentiation in stem height and stem diameter might reflect the inherent adaptation of the populations for rapid growth to escape suppression by neighboring plants during establishment and to regional differences in photoperiod, precipitation and temperature. In contrast, divergences in wood specific gravity and branch length might be correlated responses to population differentiation in stem growth. Possible bias in the estimation of FST due to Hardy-Weinberg disequilibrium (FIS not equal to 0), linkage disequilibrium, maternal effects and nonadditive genetic effects was discussed with special reference to P. contorta ssp. latifolia.

RAPD variation within and among natural populations of trembling aspen (Populus tremuloides Michx.) from Alberta

This article described the population structure of trembling aspen (Populus tremuloides Michx.) in Alberta, a dioecious tree with continuous and wide distribution, and with a primary mode of reproduction through suckering. We studied random amplified polymorphic DNA (RAPD) variation in 249 trees from eight natural populations. Trees within a population were a minimum of 200 m apart to decrease the risk of sampling ramets of a single ortet. Of a total of 28 amplified RAPD products (bands) from five random oligonucleotide primers, the frequencies at seven (25%) were heterogeneous across populations and the percentage of polymorphism averaged 90.2 per population. Estimates of Shannon's phenotypic diversity index ranged between 0.58 and 0.69 among populations, averaging 0.65. There were 246 multiband phenotypes among the 249 trees; three were each shared by two trees from different populations and the remaining 243 were unique. Thus, trees within populations probably were different clones. Analysis of molecular variance partitioned the RAPD variation into the among- and within-population components. The within-population component accounted for 97.4% of the variation and was significantly different from zero at the 2% level of probability. The among-population component, although accounting for only 2.6% of the variation, was significantly different from zero at the 1% level of probability. Pairwise tests for the homogeneity of the RAPD variance between populations suggested significant divergences among 18 of the 28 (64%) population pairs.

Nucleotide divergence between populations of trembling aspen (Populus tremuloides) estimated with RAPDs

In the present study, a total of 142 trees sampled from five populations of trembling aspen (Populus tremuloides Michx.) in Alberta was analyzed by the polymerase chain reaction (PCR) with five random oligonucleotide primers. Null-allele frequencies of 28 putative RAPD loci were estimated using the given departure from Hardy-Weinberg equilibrium (F1S) previously estimated with isozyme markers for the same population. Nucleotide divergence between populations was then estimated in a fashion similar to restriction-fragment data, but considering the dominance of the RAPDs. The average of nucleotide divergence between populations was in the order of 0.0005 and nucleotide divergence were found to be highly correlated with geographic distance. The results suggest that isolation by distance may be an important factor in the genetic differentiation of trembling aspen.

The direct cardiac effects of ketamine studied on the intact isolated rabbit heart

The effects of ketamine on the inotropic and chronotropic responsiveness of heart were examined in spontaneously beating hearts isolated from rabbits by using a modified Langendorff preparation. The changes of maximum left ventricular dP/dt from baseline level after exposing to ketamine 5, 25 and 125 micrograms/ml averaged +7.1% (P < 0.05), +2.8% (P > 0.05) and -42.6% (p < 0.001), respectively. The decreases of heart rate at the three ketamine concentrations averaged 2.4% (P < 0.05), 9.4% (P < 0.01) and 36.8% (P < 0.001), separately. Our data demonstrate that ketamine has dual actions on the cardiac inotropism. It mildly increases cardiac contractility at low concentration whereas at high concentration it depresses myocardium profoundly. Besides, ketamine produces a dose-dependent inhibition on chronotropism directly.

Chloroplast DNA inheritance in theStellaria longipes complex (Caryophyllaceae)

Inheritance of chloroplast DNA (cpDNA) was examined in F1 progenies derived from three crosses and three corresponding reciprocal crosses betweenStellaria porsildii andS. longifolia. Chloroplast DNA restriction fragments were analyzed using methods of nonradioactive digoxigenin-11-dUTP labeling and chemiluminescent detection with Lumi-Phos 530. Distinct interspecific restriction fragment polymorphisms were identified and used to demonstrate the mode of cpDNA inheritance. Mode of cpDNA inheritance differed among crosses. Two crosses in whichS. porsildii, SP2920-21, was the maternal parent exhibited three different types of plastids, maternal, paternal and biparental, among the F1 hybrids, suggesting a biparental cpDNA inheritance and plastid sorting-out inStellaria.

Genetic diversity and multilocus associations in Cunninghamia lanceolata (Lamb.) Hook from The People's Republic of China

Open-pollinated seeds were assayed for allozyme polymorphisms at 24 loci to assess genetic diversity and multilocous associations in 16 populations of Cunninghamia lanceolata (Lamb.) Hook in the People's Republic of China. On average, the percentage of polymorphic loci was 88.0, the number of alleles per locus was 3.0, and the expected heterozygosity was 0.394. The distribution of genetic diversity was not correlated with the geographic and climatic variables of the populations. However, allele frequencies correlated linearly with the mean annual temperature of the populations at Mdh-1, Mdh-2, Mnr-2, Pgi-1, and Skdh-1 and with the altitude of the populations at Aph-4 and 6Pg-2. Of the total gene diversity 6% was attributed to among-population differentiation; 94% resided within populations. Two-locus gametic disequilibria were found in 15 of the 16 populations, and higher-order gametic disquilibria were significant in most populations. The gametic disequilibria did not correlate with geographic and climatic variables. The results suggest that population subdivision, founder effect, occurrence across diverse environments, a mating system dominated by inbreeding, and historical events from 2000 years of cultivation are contributing factors in the generation and maintenance of the multilocus genetic structure in this conifer.

The hemodynamic effects of continuous intravenous infusion of propofol at higher rates

The new formula of propofol was introduced in 1985. Because of its characteristics of rapid onset and elimination, it was often used as a drug of induction and maintenance of total intravenous anesthesia. However, the hemodynamic effects of propofol was still controversial. The present study was to observe its hemodynamic reactions at higher infusion rate. Hemodynamic studies were performed in 11 female patients, 17 to 54 years old, ASA class I-II, presenting for major lower abdominal operation. Patients with heart, lung, liver, or endocrine disease were excluded. No premedication was given before anesthesia. A radial arterial line and a swan-ganz catheter were inserted under local anesthesia. Cardiac output (CO), arterial blood pressure (ABP), central venous pressure (CVP), pulmonary arterial pressure (PAP), and pulmonary capillary wedge pressure (PCWP) were obtained before induction to foster systemic vascular resistance index (SVRI), left ventricular systolic work index (LVSWI), right ventricular systolic work index (RVSWI), and pulmonary vascular resistance index (PVRI), cardiac index (CI) by an H/p computer analyzer. Propofol (2 mg/kg) was combined with succinylcholine (1.5 mg/kg) for induction. Anesthesia was maintained with propofol and norcuron. The infusion rates of propofol were 10 mg/kg/hr during the first 30 minutes and 8 mg/kg/hr during the following 30 minutes, norcuron, 0.1 mg/kg initially and 1 mg for maintenance after 30 minutes. Normal saline was infused 1000 to 1500 ml in study period to maintain higher preload. Post induction hemodynamic data were collected at the 5th, 15th, 30th, 60th min after induction.(ABSTRACT TRUNCATED AT 250 WORDS)

The effect of heated humidifier in the prevention of intra-operative hypothermia

Unintentional hypothermia is common in patients undergoing "routine anesthesia in surgery". The aims of the study were to estimate the difference of changes of body temperature during abdominal and limb operations and to evaluate the effectiveness of the heated humidifier for reducing intraoperative heat loss. Forty-three patients were randomly being allocated into 3 groups. Group I consisted of 14 patients undergoing abdominal operation without the use of heated humidifier. Another 22 patients were being assigned as group II to have a heated humidifier on the inspiratory limb of the breathing circuit. The inspired gas was warmed to 39 degrees C and the relative humidity was 90%. 7 patients undergoing limb operation were attributed to group III without using heated humidifier to humidify and warm up the inspired gas. For body temperature monitoring, the probe was placed on the patient's nasopharynx and the temperature was measured immediately before induction of anesthesia, post-intubation, and then once again every 15 minutes up to 3 hours after induction. All patients in the 3 groups showed a rapid decrease of body temperature in the first hour and then the hypothermic change was slow down. The lowest level of body temperature was reached at about 2 hours after induction. Patients undergoing abdominal operation decreased body temperature greater than those undergoing limb operation for about 2 degrees C after 3 hours of anesthesia and surgery. Warming and humidifying the inspired gas effectively reduced the heat loss. We concluded that abdominal operation induce hypothermia more than limb operation. The use of heated humidifier was effective in maintaining body temperature.

Prolonged fasting in pediatric outpatients does not cause hypoglycemia

Two hundred and thirty healthy children scheduled for receiving elective minor surgery were assigned into 4 different groups. Group I (small infant group) included 27 infants of age from 1 to 3 months (2.0 +/- 0.6 months), Group II (infant group) included 42 infants age from 3 to 12 months (7.4 +/- 2.8 months), Group III (pre-school children group) included 122 patients of age from 1 to 6 years (3.1 +/- 1.4 years). The remained 39 cases of age older than 6-years-old (8.0 +/- 1.5 years) were collected in group IV (old children group). All studied children were starved for at least 4, 6, or 8 hours in infants, pre-school children, and old children group, respectively, pre-operatively. The fasting time and fasting blood glucose levels of the 4 groups were 6.7 +/- 1.4 hours and 109.0 +/- 22.9 mg% in group I, 7.7 +/- 2.3 hours and 98.6 +/- 18.0 mg% in group II, 10.4 +/- 2.9 hours and 96.9 +/- 24.7 mg% in group III, and 12.6 +/- 2.6 hours and 95.7 +/- 20.5 mg% in group IV, respectively. No one in the 230 children had blood glucose less than 40 mg% even in 5 infants who were starved for 12 hours or more. Therefore, we concluded that preoperative starvation is well tolerated than the originally expected in the infants and children. The fasting time before anesthesia can be executed safely even though the operation schedule may not be right on time.

Multilocus structure in Pinus contorta Dougl

We studied isozyme variation at 21 loci in 66 populations from three subspecies of Pinus contorta Dougl.; 35 in spp. latifolia, 20 in spp contorta and 11 in spp. murrayana. The objectives were to assess gametic disequilibria and multilocus structure. There was considerable differentiation of allele frequencies at 19 polymorphic loci across the 66 populations and within the subspecies. Allele frequencies at many loci correlated with geographic variables. Genetic variability varied considerably among populations within subspecies but the subspecies means were similar. The mean number of polymorphic loci and the mean heterozygosity over 19 polymorphic loci were, respectively, 13 and 0.194 in latifolia, 12 and 0.196 in murrayana, and 12 and 0.180 in contorta. The mean heterozygosity correlated with longitude and altitude across the 66 populations and with latitude in latifolia. Gametic disequilibria were evident in 40 populations; 29 in latifolia, eight in murrayana and three in contorta. Gametic disequilibria correlated with latitude across the 66 populations and with longitude in latifolia. The single-locus F ST averaged 0.0339 in latifolia, 0.0567 in murrayana, and 0.0764 in contorta. The multilocus F STM was 0.1227 in latifolia, 0.2926 in murrayana, and 0.3328 in contorta. Multilocus Wahlund and founder effects, migration patterns, and natural selection, probably played significant roles in generating and maintaining the multilocus genetic structure in P. contorta in general and the subspecies latifolia in particular.

The site of action of lidocaine in intravenous regional anesthesia

Despite vast clinical experience and success with intravenous regional anaesthesia (IVRA), the site and mode of action of the local anesthetic agents remains controversial. Many investigations have been published, but conclusions are variable. The principal site of action of lidocaine in IVRA was studied using 15 ASA I-II patients receiving surgical operation on the hands and forearms. A 22 gauge plastic cannula was inserted into the median cubital vein at the elbow. A double cuff tourniquet was secured on the upper arm, as described by Bier and modified by Homes. Another single tourniquet was then applied on the forearm as near the plastic catheter as possible. Two different concentrations of lidocaine (0.5% and 2%) in a total dose of 3 mg kg-1 was slowly injected into the vein via the catheter after the limb was exsanguinated and the tourniquets were inflated. The results showed that 0.5% lidocaine produced analgesia only on the intercuff area; there was no analgesic response noted on the forearm distal to the third tourniquet after a 15 minutes observation. However patients who received 2% lidocaine experienced in analgesia rapidly on the intercuff area and also slowly on the forearm and hand. The anesthesia developed from the fingertips upward. Based on this evidence, we concluded that the principal site of action of lidocaine in IVRA depends on concentration. The lower concentration acts on the sensory nerve endings and the small nerves. Whereas, the higher concentration acts on both nerve trunks and nerve endings.

Effects of high-dose fentanyl combined with diazepam on patients after coronary artery bypass graft surgery

High-dose fentanyl has become a popular anesthetic agent for cardiac anesthesia because of its cardiac stability. Little attention has yet been paid to the relationship between the dose and problems during the early postoperative period. This study was designed to investigate whether higher doses of fentanyl combined with diazepam would influence the early-stage of postoperative conditions. Sixteen patients scheduled for elective coronary artery bypass graft (CABG) surgery were studied. All of them had adequate cardiac performance, and were randomly divided into two groups, 9 in Group I and 7 in Group II. Group I received fentanyl (less than 100 micrograms/kg) combined with diazepam (less than 0.2 mg/kg). In Group II the doses of both drugs were greater than that used in Group I. The cardiovascular changes, the maximal infusion rates of dopamine, nitroglycerin (NTG), and sodium nitroprusside (Nipride) were observed. Meanwhile, the awakening time from anesthesia, the time of extubation, and the duration of stay in the intensive care unit (ICU) were also recorded. The results showed that there were no significant differences between both groups regarding the factors studied except the maximal infusion rate of Nipride and the awakening time of post-anesthesia. We suggest that higher doses of fentanyl combined with diazepam can reduce the dosage of vasodilator but do not prolong the time of extubation and stay in ICU.

Joint estimation of immigration and mating system parameters in gymnosperms using the EM algorithm

An EM algorithm procedure is presented for the maximum-likelihood joint estimation of immigration and mating system parameters of mixed-mating system models for gymnosperms. In addition to accommodating multiallelic and multilocus data in mature populations and pollen pools, the EM estimates are insensitive to allelic frequency changes in foreign population and may approach closer to global maximum-likelihood estimates with each iteration, regardless of initial starting values. Estimates of rates of selfing (Ŝ), outcrossing (Ô), and immigration (Î) derived from the model are bounded strictly within the natural biological range (i.e., 0 ≤ Ô + Î ≤ 1; Ŝ + Ô + Î = 1).

Hypercarbia is not the determinant factor of systemic arterial hypertension during carboperitoneum in laparoscopy

Laparoscopy performed with carboperitoneum in 30 women of infertility was studied to evaluate the changes of systemic blood pressure and end-tidal carbon dioxide (CO2) and their relationship. The patients were randomly divided into 2 groups. In group I (n = 15), the patient's respiration was set to maintain a nearly constant end-tidal CO2 by adjusting the minute ventilation. In group II (n = 15), the minute ventilation was kept constant to monitor the changes of end-tidal CO2. Perioperative measurements included end-tidal CO2, systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) which were recorded the moment just before intra-abdominal CO2 administration and every 2 min thereafter for at least 10 min. The data showed that in both groups there were time-related changes of blood pressure with a maximum increase about 20-30% of baseline level found at 6 min later after the beginning of intra-peritoneal CO2 insufflation, and no significant change of HR was noted. The intergroup comparisons of SBP, DBP and HR were not statistically significant. With regard to end-tidal CO2 change in group II, it also appeared in a time-related fashion. A maximum increase was found 6 min later after the intra-abdominal CO2 administration. Our results disclosed that carboperitoneum during laparoscopy might consistently induce systemic arterial hypertension, and hypercarbia might not be the major determinant factor of hypertension.

Genetic relationship of wood and plains bison based on restriction fragment length polymorphisms

To evaluate the genetic relationship within and between wood and plains bison of Elk Island National Park, genomic DNA samples were screened for restriction fragment length polymorphisms (RFLP) with cDNA probes for growth hormone, growth hormone releasing factor, somatostatin, and insulin-like growth factor-1. Of the 28 fragments identified, two revealed RFLPs, both of which were associated with the growth hormone releasing factor locus. The observed frequencies of the polymorphic sites did not differ from a Hardy–Weinberg distribution in either population, which is indicative of random mating populations. The contingency χ2 tests for homogeneity indicate that the fragment frequencies of the polymorphic restriction sites differ significantly (P = 0.00) between the wood and plains bison. The number of net nucleotide substitutions between the two populations was 0.0007, indicative of a recent divergence. Conversion of the bison nucleotide divergence results in a relative protein divergence of 0.007 to 0.018. This converted divergence corresponds closely to the divergence reported for other geographically isolated populations; thus, this preliminary analysis suggests the bison have at least reached the stage of geographic isolation in their evolutionary divergence.

The rate of end-tidal CO2 elevation after intraabdominal CO2 insufflation in laparoscopy

Twenty-two female adults were under study by monitoring the end-tidal CO2 during laparoscopy in order to define the rate of CO2 elevation. Experimental results showed that under the intraabdominal pressure of 14.5 cm H2O (ranging from 12 to 18 cm H2O), the elevated CO2 level varied from 3 mmHg to 19 mmHg with a mean value of 8.3 +/- 3.7 mmHg (P less than 0.001). It took 10.5 +/- 1.9 min to reach peak level.

Study of plasma neuropeptide Y (NPY) and catecholamines levels during isoflurane anesthesia

Twelve ASA physical status I-II patients were studied after obtaining institutional approval and informed contents. All patients were free from endocrine and metabolic disease undergoing elective low risk operation. Pethidine 1 mg/kg i.m. and benzodiazepine 0.01 mg/kg p.o. were given as premedication one hour before anesthesia. Anesthesia was induced with thiopental 4 mg/kg and succinylcholine 1.5 mg/kg for tracheal intubation. Anesthesia was maintained with 2% isoflurane and 50% N2O in oxygen. Ventilation was controlled and adjusted to maintain an end-tidal CO2 concentration of 25-35 torr. Atracurium 0.4 mg/kg was given as muscle relaxant. Blood samples were obtained from radial arterial catheter, 15 minutes before induction of anesthesia and 5 min after anesthesia, 15 min, 30 min, 60 min during operation and 30 min after operation in postanesthesia recovery room. The results showed that there were no statistically significant changes in plasma levels of NPY and catecholamines during operation underwent isoflurane anesthetic technique. This result indicates that isoflurane anesthesia can block the plasma NPY as well as catecholamines during surgical stress.

Identification of a variant growth hormone haplotype in mice selected for high body weight

Restriction site analysis revealed a variant growth hormone gene haplotype fixed within growth-selected mice (High line-3; HL-3) exhibiting growth rates 1·5 times greater than those of unselected Foundation population (FP-3) mice. Relative to the FP-3 haplotype, the HL-3 haplotype exhibited restriction fragment length polymorphisms for each of seven different restriction enzymes. Three of the polymorphic sites lie within 1·1 kb of the 5′ end of the structural gene; a fourth polymorphism exists within the structural gene. The HL-3 haplotype was also fixed within an additional three growth-selected lines (including a replicate of HL-3). This identification of an association, between the natural variant of a growth regulating gene and a growth-related phenotype, is the prototype of experiments that could lead to the isolation of variant genes which enhance livestock production characters.

Mating system and multilocus associations in a natural population of Pseudotsuga menziesii (Mirb.) Franco

Arrays of open-pollinated seeds were assayed for allozyme polymorphisms at ten loci (Aat2, Est1, G6pd, Idh, Mdh2, Mdh3, Pgm, Sod, 6Pgd1, 6Pgd2) to obtain estimates of the outcrossing rate and assess multilocus association in a natural population of coastal Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco. The allele frequencies in the samples of adult trees and pollen-gamete pool were similar. Maximum-likelihood estimators of the outcrossing rate for individual loci and two multilocus models were derived using counting methods. The single-locus maximum likelihood estimates (MLEs) of the outcrossing rate were significantly heterogeneous; they varied over a more than two-fold range from 0.404 to 0.935, with an average MLE of 0.741. Both multilocus MLEs of the outcrossing rate were 0.887. The sample of trees was in random mating equilibrium when assessed on a pairwise-locus basis using Burrows' composite measure of gametic disequilibrium, with one exception (Mdh2 Sod) that was attributable to a rare "gametic" class. In the sample of pollen gametes, 5 of the 45 pairwise-locus associations were nominally significant at the 0.05 level: Idh Est1, Mdh2 Sod, Aat2 Est1, Aat2 Mdh3, and Est1 Mdh3. These apparent associations were attributable in most cases to the relative excess of uncommon or rare paternal gametes of discernibly outcrossed embryos. An additional two-locus association was identified for Mdh2 Pgm which was marginally significant for the major partition of the contingency table that excluded paternal gametes with the rare allele Mdh2 (2) .

Effects of sodium nitroprusside-induced hypotension on the cerebral and hindlimb blood flow in dogs

Sodium nitroprusside (SNP) has been commonly used as a vasodilator agent for deliberate hypotension with general anesthesia. The purpose of this study was to observe whether cerebral blood flow (CBF) was significantly reduced when SNP infusion was accomplished to decrease peripheral blood flows with systemic hypotension. We conducted the experiments in 15 pentobarbital-anesthetized dogs. CBF was measured in 7 dogs using a venous outflow method. Hindlimb blood flow (HBF) serving as a representative of the peripheral circulations was obtained by flow measurement in the femoral artery in 8 dogs. The systemic arteral pressure (SAP) was decreased stepwise (approximately 5 mmHg for each step) by adjusting the SNP infusion rate. During the systemic hypotension, the CBF remained fairly constant despite a marked decline in the mean SAP to 40 mmHg. The calculated cerebral vascular resistance was progressively decreased with the systemic hypotension. On the contrary, a reduction in the HBF was observed accompanying the fall in SAP. When the mean SAP was decreased to 50 mmHg, the HBF was only 46.3 +/- 7.6% of the control value. The calculated hindlimb vascular resistance was slightly elevated during the whole course of SNP-induced hypotension. The results reveal the disparity between the brain and hindlimb in the resistance and flow responses to SNP-induced hypotension. The constancy of CBF subserves adequate brain perfusion when deliberate hypotension is conducted for surgery in the peripheral organs.

TEMPORAL VARIATION OF THE MATING SYSTEM IN A NATURAL POPULATION OF JACK PINE

Mating system parameters of a northern conifer, Pinus banksiana Lamb., were estimated from allozyme polymorphisms. Seeds analyzed were obtained from serotinous cones of 30 individuals and represented four independent fertilizations in 1975, 1976, 1977 and 1978. Results indicated that a mixed mating system model, with a mean effective outcrossing rate of 88 ± 0.047%, described the mating system of this stand. However, there was an approximately linear increase in the apparent selfing rate from the oldest (1975) to the newest (1978) crop. Two hypotheses could account for these observations. First, there may have been changes in the mating system during the 4-yr period, but linearity of the differences observed in this study may have been due to chance. These changes were, however, independent of the variability of the observed pollen pool. This indicated that they were not a result of different proportions of outcrossed zygotes directly observed. Second, there could have been a more or less constant amount of selfing, followed by a differential loss of viability of selfed and outcrossed zygotes during the period of storage in the cones. Under this hypothesis, selfed zygotes are at a selective disadvantage relative to outcrossed zygotes. No differences in the mating system could be demonstrated among the three crown strata of this stand. There was significant interlocus heterogeneity in the filial generation genotypic distributions and in the estimated outcrossing rates, reflecting the complex nature of forces that can affect single-locus estimates. There was evidence of some additional inbreeding, possibly due to family structures in the stand; however, this was a minor component of the total inbreeding.

Segregation of allozymes in megagametophytes of viable seed from a natural population of jack pine, Pinus banksiana Lamb

Segregation ratios of allozymes in haploid female gametophytes obtained from viable seed were studied in a natural population of jack pine, Pinus banksiana. Stability of these ratios was assessed for three levels of the sexually reproductive crown as well as for four years of natural fertilization. Analyses of observed segregation ratios of four of five polymorphic isozyme loci showed good correspondence to the overall 1∶1 ratios expected for simple Mendelian inheritance. Allozymes of glucose-6-phosphate dehydrogenase did not segregate in the expected 1∶1 ratio. In addition, there were significant deviations from the expected segregation ratio for all the loci at some sampling positions on individual trees. Heterogeneity of segregation among trees, strata and years could be the result of pollen pool heterogeneity, segregation distortion and/or recessive lethal and semi-lethal gene combinations resulting in early embryo abortion. These types of segregation deviations in viable seed can affect the estimation of allele frequencies from bulked samples of a small number of individuals, the inference of heterozygosity/homozygosity of parental trees, and estimates of selfing rates.

Effects of ketamine on the circulatory functions and body tissue oxygenation in dogs under normal and hypovolemic conditions

Anesthetic induction with ketamine may cause cardiovascular (CV) stimulation and depression. The study was conducted in dogs to evaluate the dependence of ketamine-induced CV effects upon the dosage, mode of administration and experimental hypovolemic conditions. Slow ketamine infusion (n = 12) at 3 dose levels (5 mg/kg/min for 1, 2 and 4 min to a total dose of 5, 10 and 20 mg/kg) consistently increased the arterial pressure (AP) and heart rate (HR). Rapid bolus injections at 5, 10 and 20 mg/kg (n = 16) produced biphasic changes--decreases followed by increases in AP and HR. Profound depressor and bradycardic responses were readily observed with large dose, rapid bolus injection and during hemorrhagic hypotension. The striking CV depression in some cases became irreversible and led to death. Further study in 8 open-chest dogs revealed that ketamine infusion (a total dose of 10 mg/kg) caused slight increases in cardiac output (CO) and tissue oxygen uptake (VO2). However, the marked depressor response to bolus injection was associated with decreases in CO, total peripheral resistance, stroke volume and VO2. These inhibitory effects were prolonged after hemorrhagic hypotension. In a few cases, CO and VO2 became severely and progressively depressed and death ensued shortly following the injection.

Estimation of mating system parameters in plant populations using the EM algorithm

An EM algorithm procedure is presented for the maximum-likelihood estimation of mating system parameters of mixed mating system models for both angiosperms and gymnosperms. One advantage of the procedure is the ability to accommodate any number of alleles in the mature population and pollen pool. Estimates of the outcrossing rate ([Formula: see text]) derived from the model are bounded strictly within the natural biological range (i.e., 0 ≦ [Formula: see text] ≦1).

INHERITANCE OF ALLOZYME VARIANTS IN COASTAL DOUGLAS-FIR (PSEUDOTSUGA MENZIESII VAR. MENZIESII)

The inheritance of 27 loci from 18 enzyme systems was investigated using both megagametophyte and embryo tissues of open pollinated seed collected from a natural stand of coastal Douglas-fir [Pseudotsuga menziesii var. menziesii (Mirb.) Franco]. Four enzyme systems - glutamate dehydrogenase (GDH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), mannose-6-phosphate isomerase (MPI), and peptidase (PEP) - appeared to be monomorphic and the remaining 14 systems - acid phosphatase (APH), aconitase (ACO), aspartate aminotransferase (AAT), diaphorase (DIA), esterase (EST), glucose-6-phosphate dehydrogenase (G6P), hexoseaminidase (HA), isocitrate dehydrogenase (IDH), malate dehydrogenase (MDH), malic enzyme (ME), phosphoglucose isomerase (PGI), phosphoglucomutase (PGM), 6-phosphogluconic dehydrogenase (6-PGD), and superoxide dismutase (SOD)-showed polymorphism. Each enzyme system was discussed with respect to its multilocus organization, subunit (quaternary) structure, and allelic variation.

LINKAGE RELATIONSHIPS AMONG 19 POLYMORPHIC ALLOZYME LOCI IN COASTAL DOUGLAS-FIR (PSEUDOTSUGA MENZIESII var. MENZIESII)

Linkage relationships among 19 different polymorphic loci in coastal Douglas-fir (Pseudotsuga menziesii var. menziesii [Mirb.] Franco) were studied. A total of 115 of 171 possible two-locus combinations were tested. Out of the 115 combinations, a total of 106 conform to the hypothesis of independence between loci indicating that no linkage exists between these pairs. Of the remaining nine pairs, two were tightly linked with recombination frequencies of 0.02 (Aat2:Pgi2) and 0.22 (Aat3:Sod). The remaining were loosely linked, with recombination frequencies varying between 0.33 and 0.42. Two of these nine linked pairs have been detected in other conifer species. It was not possible to study three-point linkages due to the lack of appropriate combinations. To our knowledge, these results provide the first demonstration of genetic linkage in Douglas-fir.

Direct effects of nitroglycerin on the resistance, exchange and capacitance functions of the canine intestinal vasculature

In the isolated dog ileum perfused with constant flow, nitroglycerin (NTG) produced dose-dependent arteriolar and venous dilatation. Experiments were performed in 22 ileum preparations to advance the study on the pre- and postcapillary resistances, functional capillary pressure, capillary filtration coefficient (CFC) and vascular compliance. At venous pressure (Pv) of 0, 10 and 20 mm Hg, and intra-arterial infusion of NTG in a submaximal dose (30 microgram/min) reduced the total and precapillary resistances, but did not change the postcapillary resistance and functional capillary pressure. This agent slightly increased the CFC calculated from a Pv range of 0 to 10 mm Hg and significantly increased the CFC value calculated from a Pv change of 0 to 20 mm Hg. At Pv = 0 mm Hg, NTG infusion caused a regional volume pooling by 1.2 +/- 0.4 mg/100 g. The vascular compliance in terms of delta blood volume/delta Pv was also significantly increased after NTG. The myogenic responses (reduction in CFC and increase in precapillary resistance) to an elevation of Pv were essentially identical before and after NTG infusion. The results suggest the NTG at the dose used acts primarily on the arterioles, precapillary sphincters and postcapillary capacitance vessels. The postcapillary resistance vessels (mainly the venules) are little affected. Although the resistance and exchange vessels are dilated by NTG, the myogenic constriction of these vessels upon Pv rises is not significantly altered.

THE ORGANIZATION OF GENETIC VARIABILITY IN CENTRAL AND MARGINAL POPULATIONS OF LODGEPOLE PINE PINUS CONTORTA spp. LATIFOLIA

A survey was conducted of genetic variation at 25 loci in extracts of individual megagametophytes of lodgepole pine. Collections were made in nine widely separated localities representing four marginal, two intermediate and three central populations. Single populations of lodgepole pine were, on the average, polymorphic at 58.67% of their loci, and had 1.90 alleles per locus. Both expected and observed heterozygosity averaged 0.16. There was a definite trend towards decreased genetic variability at the margins. The measures of gene diversity for the 25 loci showed a 4% but significant effect of interpopulation differentiation; 96% of the total gene diversity resided within populations. Estimated outcrossing rates [Formula: see text] for the nine populations ranged between 0.92–1.29. Comparisons among populations with different levels of outcrossing revealed no clear relationship between [Formula: see text] and amount of genetic variability. The overall pattern of genetic differentiation agrees with expectations based on the neutral mutation theory. However, two loci demonstrated conspicuous clinal variation patterns which may be incompatible with this stochastic model.