Preoperative Hypoalbuminemia Predicts Early Mortality Following Open Abdominal Surgery in Patients Above 60 Years of Age.

BACKGROUND: Major abdominal surgery in older and frail patients is associated with considerable morbidity and mortality. Plasma albumin is routinely measured in the clinic and has been proposed as an indicator of frailty. This study aimed to investigate if plasma albumin is a predictor of mortality in older patients undergoing open abdominal surgery. MATERIALS AND METHODS: We conducted a single-center, register-based retrospective study of patients, aged ⩾60 years who underwent one of 81 open abdominal surgical procedures. Patients operated on during the period from January 1st, 2000 to May 31st, 2013 were consecutively identified in the Danish National Patient Registry. Plasma albumin was measured within 30 days prior to surgery and the primary endpoint was 30-day postoperative mortality. RESULTS: 3,639 patients were included of whom 68.2% underwent emergency surgery. The rate of severe hypoalbuminemia (plasma albumin < 28 g/L) was 43.4%. Preoperative plasma albumin was lower in patients with a fatal 30-day outcome (mean 20.6 g/L vs 30.1 g/L in survivors, p < 0.0001). Other independent predictive parameters of 30-day mortality were age, male sex, and emergency surgery. We present an algorithm including these four variables for the prediction of 30-day mortality for patients aged ⩾60 years undergoing open abdominal surgery. CONCLUSION: Preoperative plasma albumin is a predictor of 30-day mortality in patients above 60 years of age following open abdominal surgery. Assessment of plasma albumin in conjunction with other risk factors such as age, sex, and surgical priority may improve preoperative decision-making.

No increased sperm DNA fragmentation index in semen containing human papillomavirus or herpesvirus.

It remains unknown whether human papillomaviruses (HPVs) or human herpesviruses (HHVs) in semen affect sperm DNA integrity. We investigated whether the presence of these viruses in semen was associated with an elevated sperm DNA fragmentation index. Semen from 76 sperm donors was examined by a PCR-based hybridization array that identifies all HHVs and 35 of the most common HPVs. Sperm DNA integrity was determined by the sperm chromatin structure assay. HPVs or HHVs, or both, were found in 57% of semen samples; however, sperm DNA fragmentation index was not increased in semen containing these viruses.

Intubation conditions after rocuronium or succinylcholine for rapid sequence induction with alfentanil and propofol in the emergency patient.

BACKGROUND AND OBJECTIVE: Previous studies mainly conducted on elective patients recommend doses of 0.9-1.2 mg kg[-1] rocuronium to obtain comparable intubation conditions with succinylcholine 1.0 mg kg[-1] after 60 s during a rapid-sequence induction. We decided to compare the overall intubating conditions of standard doses of rocuronium 0.6 mg kg[-1] and succinylcholine 1.0 mg kg[-1] during a strict rapid-sequence induction regimen including propofol and alfentanil. METHODS: Male and female patients (ASA I-III) older than 17 yr scheduled for emergency abdominal or gynaecological surgery and with increased risk of pulmonary aspiration of gastric content were randomized to a rapid-sequence induction with succinylcholine 1.0 mg kg[-1] or rocuronium 0.6 mg kg[-1]. Patients with a predicted difficult airway were excluded. A senior anaesthesiologist 'blinded' for the randomization performed the intubation 60 s after injection of the neuromuscular blocker. Intubating conditions were evaluated according to an established guideline. Tracheal intubation not completed within 30 s was recorded as failed. RESULTS: 222 patients were randomized. Three patients had their operation cancelled and 10 did not fulfil the inclusion criteria. Clinically acceptable intubation conditions were present in 93.5% and 96.1% of patients in the succinylcholine group (n=107) and the rocuronium group (n=102), respectively (P=0.59). CONCLUSIONS: During a rapid-sequence induction with alfentanil and propofol, both rocuronium 0.6 mg kg[-1] and succinylcholine 1.0 mg kg[-1] provide clinically acceptable intubation conditions in 60 s in patients scheduled for emergency surgery. Under the conditions of this rapid-sequence induction regimen rocuronium may be a substitute for succinylcholine.

Polybrominated diphenyl ethers: occurrence, dietary exposure, and toxicology.

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in plastics (concentration, 5--30%) and in textile coatings. Commercial products consist predominantly of penta-, octa-, and decabromodiphenyl ether mixtures, and global PBDE production is about 40,000 tons per year. PBDEs are bioaccumulated and biomagnified in the environment, and comparatively high levels are often found in aquatic biotopes from different parts of the world. During the mid-1970--1980s there was a substantial increase in the PBDE levels with time in both sediments and aquatic biota, whereas the latest Swedish data (pike and guillemot egg) may indicate that levels are at steady state or are decreasing. However, exponentially increasing PBDE levels have been observed in mother's milk during 1972--1997. Based on levels in food from 1999, the dietary intake of PBDE in Sweden has been estimated to be 0.05 microg per day. Characteristic end points of animal toxicity are hepatotoxicity, embryotoxicity, and thyroid effects as well as maternal toxicity during gestation. Recently, behavioral effects have been observed in mice on administration of PBDEs during a critical period after birth. Based on the critical effects reported in available studies, we consider the lowest-observed-adverse-effect level (LOAEL) value of the PBDE group to be 1 mg/kg/day (primarily based on effects of pentaBDEs). In conclusion, with the scientific knowledge of today and based on Nordic intake data, the possible consumer health risk from PBDEs appears limited, as a factor of over 10(6) separates the estimated present mean dietary intake from the suggested LOAEL value. However, the presence of many and important data gaps, including those in carcinogenicity, reproduction, and developmental toxicity, as well as additional routes of exposure, make this conclusion only preliminary. Moreover, the time trend of PBDEs in human breast milk is alarming for the future.

The Arabidopsis eer1 mutant has enhanced ethylene responses in the hypocotyl and stem.

By screening for enhanced ethylene-response (eer) mutants in Arabidopsis, we isolated a novel recessive mutant, eer1, which displays increased ethylene sensitivity in the hypocotyl and stem. Dark-grown eer1 seedlings have short and thick hypocotyls even in the absence of added ethylene. This phenotype is suppressed, however, by the ethylene biosynthesis inhibitor 1-aminoethoxyvinyl-glycine. Following ethylene treatment, the dark-grown eer1 hypocotyl response is greatly exaggerated in comparison with the wild type, indicating that the eer1 phenotype is not simply due to ethylene overproduction. eer1 seedlings have significantly elevated levels of basic-chitinase expression, suggesting that eer1 may be highly sensitive to low levels of endogenous ethylene. Adult eer1 plants display exaggerated ethylene-dependent stem thickening, which is an ethylene response previously unreported in Arabidopsis. eer1 also has enhanced responsiveness to the ethylene agonists propylene and 2,5-norbornadiene. The eer1 phenotype is completely suppressed by the ethylene-insensitive mutation etr1-1, and is additive with the constitutive ethylene-response mutation ctr1-3. Our findings suggest that the wild-type EER1 product acts to oppose ethylene responses in the hypocotyl and stem.

Effect of aluminum on cytoplasmic Ca2+ homeostasis in root hairs of Arabidopsis thaliana (L.).

Aluminum inhibition of root growth is a major world agricultural problem where the cause of toxicity has been linked to changes in cellular calcium homeostasis. Therefore, the effect of aluminum ions (Al) on changes in cytoplasmic free calcium concentration ([Ca2+]c) was followed in root hairs of wild-type, Al-sensitive and Al-resistant mutants of Arabidopsis thaliana (L.) Heynh. Generally, Al exposure resulted in prolonged elevations in tip-localized [Ca2+]c in both wild-type and Al-sensitive root hairs. However, these Al-induced increases in [Ca2+]c were not tightly correlated with growth inhibition, occurring up to 15 min after Al had induced growth to stop. Also, in 32% of root hairs examined growth stopped without a detectable change in [Ca2+]c. In contrast, Al-resistant mutants showed little growth inhibition in response to AlCl3 exposure and in no case was a change in [Ca2+]c observed. Of the other externally applied stresses tested (oxidative and mechanical stress), both were found to inhibit root hair growth, but only oxidative stress (H2O2, 10 microM) caused a prolonged rise in [Ca2+]c similar to that induced by Al. Again this increase occurred after growth had been inhibited. The lack of a tight correlation between Al exposure, growth inhibition and altered [Ca2+]c dynamics suggests that although exposure of root hairs to toxic levels of Al causes an alteration in cellular Ca2+ homeostasis, this may not be a required event for Al toxicity. The elevation in [Ca2+]c induced by Al also strongly suggests that the phytotoxic action of Al in root hairs is not through blockage of Ca2(+)-permeable channels required for Ca2+ influx into the cytoplasm.

Association of the Arabidopsis CTR1 Raf-like kinase with the ETR1 and ERS ethylene receptors.

In Arabidopsis thaliana, signal transduction of the hormone ethylene involves at least two receptors, ETR1 and ERS, both of which are members of the two-component histidine protein kinase family that is prevalent in prokaryotes. The pathway also contains a negative regulator of ethylene responses, CTR1, which closely resembles members of the Raf protein kinase family. CTR1 is thought to act at or downstream of ETR1 and ERS based on double mutant analysis; however, the signaling mechanisms leading from ethylene perception to the regulation of CTR1 are unknown. By using the yeast two-hybrid assay, we detected a specific interaction between the CTR1 amino-terminal domain and the predicted histidine kinase domain of ETR1 and ERS. We subsequently verified these interactions by using an in vitro protein association assay(s). In addition, we determined that the amino-terminal domain of CTR1 can associate with the predicted receiver domain of ETR1 in vitro. Based on deletion analysis, the portion of CTR1 that interacts with ETR1 roughly aligns with the regulatory region of Raf kinases. These physical associations support the genetic evidence that CTR1 acts in the pathway of ETR1 and ERS and suggest that these interactions could be involved in the regulation of CTR1 activity.

Aluminum-resistant Arabidopsis mutants that exhibit altered patterns of aluminum accumulation and organic acid release from roots.

Al-resistant (alr) mutants of Arabidopsis thaliana were isolated and characterized to gain a better understanding of the genetic and physiological mechanisms of Al resistance. alr mutants were identified on the basis of enhanced root growth in the presence of levels of Al that strongly inhibited root growth in wild-type seedlings. Genetic analysis of the alr mutants showed that Al resistance was semidominant, and chromosome mapping of the mutants with microsatellite and random amplified polymorphic DNA markers indicated that the mutants mapped to two sites in the Arabidopsis genome: one locus on chromosome 1 (alr-108, alr-128, alr-131, and alr-139) and another on chromosome 4 (alr-104). Al accumulation in roots of mutant seedlings was studied by staining with the fluorescent Al-indicator dye morin and quantified via inductively coupled argon plasma mass spectrometry. It was found that the alr mutants accumulated lower levels of Al in the root tips compared with wild type. The possibility that the mutants released Al-chelating organic acids was examined. The mutants that mapped together on chromosome 1 released greater amounts of citrate or malate (as well as pyruvate) compared with wild type, suggesting that Al exclusion from roots of these alr mutants results from enhanced organic acid exudation. Roots of alr-104, on the other hand, did not exhibit increased release of malate or citrate, but did alkalinize the rhizosphere to a greater extent than wild-type roots. A detailed examination of Al resistance in this mutant is described in an accompanying paper (J. Degenhardt, P.B. Larsen, S.H. Howell, L. V. Kochian [1998] Plant Physiol 117: 19-27).

Aluminum resistance in the Arabidopsis mutant alr-104 is caused by an aluminum-induced increase in rhizosphere pH.

A mechanism that confers increased Al resistance in the Arabidopsis thaliana mutant alr-104 was investigated. A modified vibrating microelectrode system was used to measure H+ fluxes generated along the surface of small Arabidopsis roots. In the absence of Al, no differences in root H+ fluxes between wild type and alr-104 were detected. However, Al exposure induced a 2-fold increase in net H+ influx in alr-104 localized to the root tip. The increased flux raised the root surface pH of alr-104 by 0.15 unit. A root growth assay was used to assess the Al resistance of alr-104 and wild type in a strongly pH-buffered nutrient solution. Increasing the nutrient solution pH from 4.4 to 4.5 significantly increased Al resistance in wild type, which is consistent with the idea that the increased net H+ influx can account for greater Al resistance in alr-104. Differences in Al resistance between wild type and alr-104 disappeared when roots were grown in pH-buffered medium, suggesting that Al resistance in alr-104 is mediated only by pH changes in the rhizosphere. This mutant provides the first evidence, to our knowledge, for an Al-resistance mechanism based on an Al-induced increase in root surface pH.

Arabidopsis mutants with increased sensitivity to aluminum.

Al-sensitive (als) mutants of Arabidopsis were isolated and characterized with the aim of defining mechanisms of Al toxicity and resistance. Most als mutants selected on the basis of root growth sensitivity to Al were recessive, and together the mutants constituted eight complementation groups. Also, in most als mutants, Al sensitivity appeared to be specific for Al relative to La (another trivalent cation), except als2, which was more sensitive to La than wild type. The tendency of roots on mutant seedlings to accumulate Al was examined by staining with morin and hematoxylin, dyes used to indicate the presence of Al. A significant increase in morin staining was observed in als5, consistent with its increased sensitivity to Al. Unexpectedly, als7 and als4 showed less morin staining, suggesting that the roots on these mutants accumulate less Al than wild type seedlings after exposure to Al-containing solutions. Roots of wild-type seedlings produce callose in response to AlCl3 concentrations that inhibit root growth. Only als5 accumulated more callose than wild type in response to low levels (25 mu M) of AICI3 However, als4 and als7 did not accumulate callose at this AlCl3 concentration even though root growth was significantly inhibited. The lack of callose accumulation in als4 and als7 suggests that there is not an obligatory relationship between callose deposition and Al-induced inhibition of root growth.

Pollination-Induced Ethylene in Carnation (Role of Pollen Tube Growth and Sexual Compatibility).

The pollen-pistil interactions that result in the stimulation of ethylene production and petal senescence in carnation (Dianthus caryophyllus L.) flowers were investigated. Pollination of White Sim flowers with Starlight pollen elicited an increase in ethylene production by styles, leading to increased petal ethylene and premature petal senescence. In contrast, pollination with 87-29G pollen led to an early increase in ethylene production, but this was not sustained, and did not lead to petal senescence. Both Starlight and 87-29G pollen germinated on White Sim stigmas and their tubes grew at similar rates, penetrating the length of the style. Crosses between Starlight and White Sim led to the production of viable seeds, whereas 87-29G pollen was infertile on White Sim flowers. Pollination of other carnations with 87-29G elicited ethylene production and petal senescence and led to the production of viable seeds. These results suggest that physical growth of pollen tubes is insufficient to elicit a sustained increase in ethylene production or to lead to the production of signals necessary for elicitation of petal ethylene production and senescence. Rather, the cell-cell recognition reactions leading to sexual compatibility in Dianthus appear to play a role in this interorgan signaling after pollination.

Ethylene-regulated expression of a carnation cysteine proteinase during flower petal senescence.

The senescence of carnation (Dianthus caryophyllus L.) flower petals is regulated by the phytohormone ethylene and is associated with considerable catabolic activity including the loss of protein. In this paper we present the molecular cloning of a cysteine proteinase and show that its expression is regulated by ethylene and associated with petal senescence. A 1600 bp cDNA was amplified by polymerase chain reaction using a 5'-specific primer and 3'-nonspecific primer designed to amplify a 1-aminocyclopropane-1-carboxylate synthase cDNA from reverse-transcribed stylar RNA. The nucleotide sequence of the cloned product (pDCCP1) was found to share significant homology to several cysteine proteinases rather than ACC synthase. A single open reading frame of 428 amino acids was shown to share significant homology with other plant cysteine proteinases including greater than 70% identity with a cysteine proteinase from Arabidopsis thaliana. Amino acids in the active site of cysteine proteinases were conserved in the pDCCP1 peptide. RNA gel blot analysis revealed that the expression of pDCCP1 increased substantially with the onset of ethylene production and senescence of petals. Increased pDCCP1 expression was also associated with ethylene production in other senescing floral organs including ovaries and styles. The pDCCP1 transcript accumulated in petals treated with exogenous ethylene within 3 h and treatment of flowers with 2,5-norbornadiene, an inhibitor of ethylene action, prevented the increase in pDCCP1 expression in petals. The temporal and spatial patterns of pDCCP1 expression suggests a role for cysteine proteinase in the loss of protein during floral senescence.

Coronary bypass grafting in the elderly. Single versus bilateral internal mammary artery grafts.

A surgical experience between October 1983 and December 1990, with 1467 consecutive patients 65 years of age and over, was used to compare patients receiving single internal mammary artery grafts (n = 736) with those receiving bilateral internal mammary artery grafts (n = 731). The mean age in the single-graft group was 73.2 years and 70.9 years in the bilateral-graft group (p < 0.001). Various clinical parameters were analyzed that revealed that the single-graft group had more women and more patients with unstable angina, a history of previous myocardial infarction, and emergency surgery (p < 0.05). There was no significant difference in cigarette smoking, hypertension, diabetes mellitus, hyperlipidemia, triple vessel coronary artery disease, left main coronary artery stenosis, or left ventricular function between the two groups. Hospital mortality for the single-graft group was 6.4% (47 patients) and 3.1% (23 patients) for the bilateral-graft group (p < 0.004). No significant difference was observed between the groups in the rate of reoperation for bleeding, sternal infection, respiratory failure, stroke, or perioperative infarction. Follow-up was obtained in 663 hospital survivors (96.4%) in the single-graft group and in 691 (97.7%) in the bilateral-graft group. Mean follow-up in the single-graft group was 42.5 months (range, 1 to 92.4 months) and 43.0 months (range, 1 to 90.3 months) in the bilateral-graft group. In the single-graft group, survival was 60.7% +/- 4.8% (+/- standard error of the mean) at 8 years (60 patients at risk); it was 67.9% +/- 8.1% (18 patients at risk) for the bilateral-graft group (p < 0.028). This comparative study demonstrates that bilateral internal mammary artery grafting can be accomplished in elderly patients with low operative risk and hospital morbidity. Moreover, patients in both groups had a reduction in cardiac events and significant functional improvement.

Bilateral internal mammary artery grafts in patients with left main coronary artery disease.

The use of the internal mammary artery (IMA) in myocardial revascularization has been expanded with bilateral and sequential grafting. However, its application in the presence of left main coronary artery stenosis (LMCAS) has not been well established. From September 1983 through December 1990, 280 patients with LMCAS greater than 50% were revascularized (3.4 mean grafts per patient) with bilateral IMA and saphenous vein grafts. Eighty-one were sequential IMA grafts. There were 234 males (83.6%) and 46 females (16.4%) with a mean age of 64.4 years (range 39 to 84 years). Preoperatively, there were six patients (2.1%) in New York Heart Association (NYHA) Class I, 30 patients (10.7%) in Class II, 130 patients (46.4%) in Class III, and 114 patients (40.7%) in Class IV. Fifty-six patients (20.0%) had an ejection fraction less than 50%. Intraaortic balloon counterpulsation was used preoperatively in 26 patients (9.3%) and intraoperatively in 11 patients (3.9%). There were four hospital deaths (1.4%). Hospital complications included: reoperation for bleeding, 7 patients (2.5%); pulmonary insufficiency, 21 patients (7.5%); perioperative infarction, 14 patients (5.0%); and stroke, 4 patients (1.4%). Follow-up was obtained in 276 hospital survivors (100.0%) with a mean of 33.4 months. There were 20 late deaths (7.1%): seven cardiac related and 12 noncardiac related. Postoperative assessment reveals substantial functional improvement. These results furnish evidence that bilateral IMA grafts can be accomplished with a low operative risk and can provide excellent functional results in patients with LMCAS.

Expression of ethylene biosynthetic pathway transcripts in senescing carnation flowers.

We have examined the expression of mRNAs for S-adenosylmethionine synthetase (EC 2.5.1.6), 1-aminocyclopropane-1-carboxylate (ACC) synthase (EC 4.4.1.14), and the ethylene-forming enzyme (EFE) in various floral organs of carnation (Dianthus caryophyllus) during the increase in ethylene biosynthesis associated with petal senescence. The abundance of ACC synthase and EFE mRNAs increased and S-adenosylmethionine synthetase transcripts decreased concomitantly with the ethylene climacteric in senescing petals. The increase in abundance of ACC synthase and EFE mRNAs in aging flowers was prevented by treatment with the ethylene action inhibitor 2,5-norbornadiene. Furthermore, an increase in ACC synthase and EFE transcripts was detected in petals from presenescent flowers within 3 to 6 hours of exposure to 2 microliters per liter of ethylene. The increase in ethylene production by senescing petals was associated with a concomitant increase in ethylene biosynthesis in styles, ovary, and receptacle tissues. In all tissues, this increase was associated with increased activities of ACC synthase and EFE. The increase in EFE activities by all floral organs examined was correlated with increased abundance of EFE transcripts. In contrast, the level of ACC synthase mRNA, as detected by the cDNA probe pCARACC3, did not always reflect enzyme activity. The combined tissues of the pistil exhibited high rates of ACC synthase activity but contained low levels of ACC synthase mRNAs homologous to pCARACC3. In addition, pollinated styles exhibited a rapid increase in ethylene production and ACC synthase activity but did not accumulate detectable levels of ACC synthase mRNA until several hours after the initiation of ethylene production. These results suggest that transcripts for ACC synthase leading to the early postpollination increase in ACC synthase activity and ethylene production are substantially different from the mRNA for the ethylene-responsive gene represented by pCARACC3.

Bilateral internal mammary artery grafts in reoperative and primary coronary bypass surgery.

Bilateral internal mammary artery grafting is recognized as a preferred method of myocardial revascularization. However, its efficacy in coronary bypass reoperation has not been clearly established. From January 1982 through June 1989, 88 patients underwent coronary bypass reoperation with bilateral internal mammary artery grafts. Results were compared with those for a subset of 88 patients receiving primary revascularization with bilateral internal mammary artery grafts who were computer matched for sex, age, left ventricular function, anginal classification, and left main coronary artery disease. In each group, 62.5% (55 patients) had unstable angina, 43.2% (38 patients) had reduced ejection fraction, and 21.6% (19 patients) in the reoperation group and 20.5% (18 patients) in the reference group had left main coronary artery disease. Hospital mortality for the reoperation group was 6.8% (6 patients) and for the reference group, 3.4% (3 patients). No significant difference was found in the incidence of reoperation for bleeding, sternal infection, or stroke in the two groups. The incidence of respiratory insufficiency in the reoperation group was 13.6% (12 patients) and in the reference group, 3.4% (3 patients) (p less than 0.015). Recurrent angina occurred in 13.7% (10 patients) of patients in the reoperation group and 13.3% (10 patients) in the reference group. The long-term survival at 5 years for the reoperation group was 85.3% +/- 5.6% (+/- standard error of the mean) and for the reference group, 91.6% +/- 3.1%. No significant difference was found in the equality of survival distribution for the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Seventeen-year experience with bilateral internal mammary artery grafts.

The internal mammary artery (IMA) is being recognized as the conduit of choice for myocardial revascularization. From January 1972 through June 1988, 1,087 patients received bilateral IMA and supplemental vein grafts. There were 917 men (84.4%) and 170 women (15.6%) with a mean age of 62.4 years (range, 29 to 84 years). Three hundred ninety-four patients (36.2%) had unstable angina, and 194 (17.8%) had left main coronary artery stenosis greater than 50%. In all, 3,741 coronary grafts were performed, with a mean of 3.4 per patient. Hospital mortality was 2.7% (29 patients). Hospital complications included reoperation for bleeding, 19 patients (1.7%); sternal infection, 16 patients (1.5%); respiratory failure, 35 patients (3.2%); perioperative myocardial infarction, 22 patients (2.0%); and stroke, 20 patients (1.8%). Post-operative arteriography in 53 patients (mean postoperative time, 53.0 months) showed that 92.1% (58/63) of the left IMA and 84.9% (45/53) of the right IMA grafts were patent. Follow-up was completed on 1,058 hospital survivors. There were 82 late deaths (7.8%). The actuarial survival for patients discharged from the hospital was 80.0 +/- 3.2% (plus or minus standard error of the mean) at 10 years and 60.0% +/- 5.0% at 15 years. At follow-up, 866 patients (90.3%) were asymptomatic and in New York Heart Association class I and 68 (7.1%) were in class II. This longitudinal analysis demonstrates that bilateral IMA grafting has a low operative risk and provides excellent long-term functional improvement and survival.

Enhancement of human natural cytotoxicity by Plasmodium falciparum antigen activated lymphocytes.

Mononuclear cells (MNC) isolated from malaria immune donors and from donors never exposed to malaria were stimulated in vitro with soluble purified Plasmodium falciparum antigens (SPag) or PPD. After 7 days of culture the proliferative response and the cytotoxic activity against the natural killer cell (NK cell) sensitive cell line, K562, were measured. It was found that SPag stimulation enhanced cytotoxic activity of MNC from donors whose lymphocytes exhibited a strong proliferative response to the antigen. MNC with low proliferative responsiveness showed increased cytotoxic activity if the MNC were preincubated with interleukin 2 (IL-2) for one hour before the start of the cytotoxic assay. SPag activation did not enhance the cytotoxic activity of MNC which did not respond to the antigen in the proliferation assay, and preincubation of these cells with IL-2 did not increase the activity. PPD stimulation enhanced the cytotoxic activity and induced strong proliferative responses in all MNC preparations. The role of NK cells in the protection against malaria is unknown, but they play a role in the protection against virus infection and in the immune surveillance against cancer. Our findings indicate that malaria antigens either directly or through the activation of immunoregulatory cells enhance the NK cell activity.

Twelve-year experience with bilateral internal mammary artery grafts.

A 12 1/2-year experience with 227 patients who underwent coronary revascularization with bilateral internal mammary artery (IMA) and supplemental saphenous vein grafts is presented. There were 725 coronary grafts performed (3.2 per patient). Forty-four IMA grafts were sequential. In 42 patients, the right IMA was placed through the transverse sinus to revascularize the circumflex artery. Operative mortality was 4% (9 of 227 patients). Postoperative complications included sternal infection (4 patients), reexploration for bleeding (5), and diaphragmatic dysfunction (10). Postoperative arteriography in 30 patients (mean interval, 4 1/4 years) revealed that 92% (34/37) of the left IMA and 87% (26/30) of the right IMA grafts were patent. Late follow-up was complete in 207 surviving patients. Eighteen late deaths (9 cardiac and 9 noncardiac) occurred. Actuarial survival was 83% at 10 years after operation. Of 68 patients followed from 8 to 12 1/2 years (mean interval, 10 1/2 years), 69% were asymptomatic, and 28% were in New York Heart Association Functional Class II. We conclude that bilateral IMA grafting can be accomplished with low operative risk and provides excellent long-term results.