Extensive multiple test centre evaluation of the VecTest malaria antigen panel assay.

To determine which species and populations of Anopheles transmit malaria in any given situation, immunological assays for malaria sporozoite antigen can replace traditional microscopical examination of freshly dissected Anopheles. We developed a wicking assay for use with mosquitoes that identifies the presence or absence of specific peptide epitopes of circumsporozoite (CS) protein of Plasmodium falciparum and two strains of Plasmodium vivax (variants 210 and 247). The resulting assay (VecTest Malaria) is a rapid, one-step procedure using a 'dipstick' test strip capable of detecting and distinguishing between P. falciparum and P. vivax infections in mosquitoes. The objective of the present study was to test the efficacy, sensitivity, stability and field-user acceptability of this wicking dipstick assay. In collaboration with 16 test centres world-wide, we evaluated more than 40 000 units of this assay, comparing it to the standard CS ELISA. The 'VecTest Malaria' was found to show 92% sensitivity and 98.1% specificity, with 97.8% accuracy overall. In accelerated storage tests, the dipsticks remained stable for > 15 weeks in dry conditions up to 45 degrees C and in humid conditions up to 37 degrees C. Evidently, this quick and easy dipstick test performs at an acceptable level of reliability and offers practical advantages for field workers needing to make rapid surveys of malaria vectors.

Dipsticks for rapid detection of plasmodium in vectoring anopheles mosquitoes.

Malaria remains the most serious vector-borne disease, affecting some 300-500 million people annually, transmitted by many species of Anopheles mosquitoes (Diptera: Culicidae). Monoclonal antibodies developed against specific circumsporozoite (CS) proteins of the main malaria parasites Plasmodium falciparum and P. vivax have been used previously for enzyme-linked immunosorbent assays (ELISA), widely employed for detection of malaria sporozoites in vector Anopheles for local risk assessment, epidemiological studies and targeting vector control. However, ELISA procedures are relatively slow and impractical for field use. To circumvent this, we developed rapid wicking assays that identify the presence or absence of specific peptide epitopes of CS protein of the most important P. falciparum and two strains (variants 210 and 247) of the more widespread P. vivax. The resulting assay is a rapid, one-step procedure using a 'dipstick' wicking test strip. In laboratory assessment, dipsticks identified 1 ng/ mL of any of these three CS protein antigens, with sensitivity nearly equal to the CS standard ELISA. We have developed and are evaluating a combined panel assay that will be both qualitative and quantitative. This quick and easy dipstick test (VecTest Malaria) offers practical advantages for field workers needing to make rapid surveys of malaria vectors.

Rare clinical diagnosis of dendriform pulmonary ossification.

Dendriform pulmonary ossification, defined as "widespread heterotopic bone formation within the lungs," is a rare entity, which is usually diagnosed upon postmortem examination. The case of a 43-year-old man with dendriform pulmonary ossification is presented. In this patient's case, thoracoscopic biopsy was an excellent diagnostic modality for identifying dendriform pulmonary ossification. Although this entity has been reported rarely, with improved technology and survival we might expect its prevalence to increase.

Attraction of Anopheles (Diptera: culicidae) to volatile chemicals in Western Kenya.

Anopheles gambiae s.l. and Anopheles funestus Giles are the primary vectors of malaria in East Africa. Identification of host-location olfactory cues may increase trap sensitivity for vector control and surveillance programs. Solid-state army miniature light traps were operated near sleeping humans in huts at night without lights and augmented with the potential attractants: L-lactic acid, Limburger cheese volatiles, hexanoic acid, and carbon dioxide. Mosquito response varied between species and gender. Female An. funestus exhibited a greater response to traps baited with L-lactic acid in combination with carbon dioxide than carbon dioxide alone in two different experiments.

Experimental detection of Rift Valley fever virus by reverse transcription-polymerase chain reaction assay in large samples of mosquitoes.

A reverse transcription-polymerase chain reaction (RT-PCR) was assessed in laboratory tests to detect the presence of single Aedes aegypti (L.) or Eretmapodites quinquevittatus Theobald mosquitoes infected with Rift Valley fever virus in pools of mosquitoes, 50-600 in size, from laboratory colonies or mixed field collections. The viral RNA was detected in all pools containing infected mosquitoes and was shown to be as sensitive as infant mice but more sensitive than Vero cell cultures for virus detection. Pools diluted down to the equivalent of 1:16 000 mosquitoes were also positive by RT-PCR. RNAs from 4 other phleboviruses were negative, there were no false positives and the procedure followed, with the 2 particular primers chosen, gave consistently clear bands of the PCR products on agarose gels without nested PCR being necessary.

Coronary artery bypass grafting in patients with transplanted livers.

Coronary artery bypass grafting was performed on 3 patients for refractory angina pectoris 48, 5, and 40 months after orthotopic liver transplantation. At the time of the cardiac operation, all 3 patients had drug-induced moderate renal dysfunction, and 1 of the 3 exhibited mild chronic rejection of the graft. Maintenance immunosuppressive therapy was continued during the cardiac operation and the perioperative period. Stress-dose steroids and standard prophylactic antibiotics were also employed. All 3 patients tolerated the cardiac surgical procedure without hepatic decompensation, excessive bleeding, infection, impaired wound healing, and other complications related to the transplanted organ or to the immunosuppressive therapy. Early postoperative liver function test results showed mild transient deterioration. One patient experienced a brief psychotic episode and massive upper gastrointestinal bleeding. Both complications were attributed to the steroids used in immunosuppressive therapy. Follow-up ranging from 2 to 24 months after coronary artery bypass grafting revealed that the patients were active and had no cardiac symptoms or manifestations of hepatic decompensation. It appears from this limited experience that cardiac operations can be performed safely in patients who have previously undergone liver transplantation.

Heparin resistance after preoperative heparin therapy or intraaortic balloon pumping.

Heparin resistance, defined as failure of 500 IU per kilogram of body weight of heparin to prolong the activated clotting time (ACT) to 480 seconds or longer, was noted during 949 of 4,280 (22%) consecutive open heart surgical procedures performed on adults between 1986 and 1991. The total population was divided into the following four groups: group 1, preoperative intraaortic balloon support without concomitant heparin therapy (n = 138 patients); group 2, preoperative intravenous heparin therapy (n = 741 patients); group 3, intraaortic balloon support with concomitant intravenous heparin therapy (n = 137 patients); and group 4, controls, not receiving preoperatively the therapy given groups 1, 2, or 3 (n = 3,264 patients). The ACT response to an initial dose of 500 IU/kg of heparin and the incidence of heparin resistance were 596 +/- 203 seconds and 30% in group 1; 506 +/- 149 seconds and 50% in group 2; 520 +/- 159 seconds and 53% in group 3; and 705 +/- 234 seconds and 14% in group 4, respectively. These results indicate that preoperative intravenous therapy and intraaortic balloon support are associated with a decreased ACT response to intraoperative heparin. Baseline ACT levels and preoperative platelet counts were not predictive of heparin resistance. A reduced ACT response to the initial dose of heparin was associated with increased requirements for supplementary anticoagulant therapy during the ensuing period on cardiopulmonary bypass, indicating that the decreased sensitivity to heparin extends beyond the initial episode of heparinization.(ABSTRACT TRUNCATED AT 250 WORDS)

Pack and close approach to persistent postcardiopulmonary bypass bleeding.

Persistent intraoperative hemorrhage after cardiopulmonary bypass was managed in three patients by packing the suspected bleeding sites with surgical sponges, leaving the packs in place and closing all layers of the sternal wound. The maneuver reduced the rate of bleeding to acceptable levels. The day after the primary operation the wounds were reopened and the surgical sponges were removed. Bleeding had ceased and the operative field remained dry in all three patients. Definitive closure of the sternotomy incisions was then performed. The method is proposed as a simpler alternative to the commonly used approach of leaving the mediastinum open for days and closing the wound after the bleeding stopped.

Replacement of the thoracic aorta with intraluminal sutureless prosthesis.

A survey of the collective experience reveals that between 1976 and 1990, a sutureless intraluminal prosthesis was used to replace the ascending thoracic aorta, arch, and descending thoracic aorta in 122, 14, and 81 patients, respectively. During these 217 operations, at least 364 of the 434 anastomoses were performed by sutureless fixation. The underlying disease processes consisted of acute and chronic dissections; atherosclerotic, Marfan's, and mycotic aneurysms; and intraoperative disruptions of the ascending aorta. The data in the literature suggest that sutureless fixation shortens aortic cross-clamp time and reduces blood loss. Early graft-related complications were few and probably can be further reduced by improving surgical techniques. The incidence of paraplegia and renal failure after descending aortic grafting was identical at 2.5%. The operative mortality rate for ascending aortic, arch, and descending aortic replacement was 13.1%, 42.9%, and 14.8%, respectively. Long-term follow-up of 143 patients revealed satisfactory graft function with three possible device-related deaths and no other known complications attributable to the prosthesis. There are, however, anecdotal references to late complications from the intraluminal prosthesis. Most of these relate to faulty implantation techniques, but some could be due to flaws inherent in the concept of sutureless grafting. The collective experience suggests that grafting of the thoracic aorta is less hazardous with the sutureless than with the conventional sutured anastomosis technique. The implications of the anecdotal accounts about late complications remain to be determined.

Thoracic surgery and the war against smoking: Richard H. Overholt, MD.

Richard H. Overholt was born at the beginning of the twentieth century when thoracic surgery hardly existed. During the first 20 years of his life progress in the field was slow. The next 20 years, which coincided with Overholt's surgical training and his early years as a thoracic surgeon, saw a rapid and almost explosive growth. Overholt's contributions were legion. They included the world's first successful right pneumonectomy, advancements in surgical treatment of tuberculosis, development of segmental resection, and introduction of the prone operative position. He was a bold and creative pioneer thoracic surgeon with consumate technical skills. Sixty years ago, when Overholt started his career as a thoracic surgeon, the hazards of smoking were not appreciated, the habit was fashionable, and consumption of tobacco was rapidly rising. In the early 1930s Overholt was among the very few physicians who recognized the perils of smoking and initiated a long but initially unrewarding antismoking crusade. By the early 1950s evidence about the ill effects of tobacco use began to accumulate. Organized medicine, voluntary health groups, and governmental agencies joined in a concerted effort to educate and to contain smoking. During the ensuing 30 years the antismoking movement achieved ever-increasing success. Today, it is widely recognized that smoking is a major health hazard and tobacco consumption is on the decline. Richard Overholt issued the first warning signals about the perils of tobacco and served as an indefatigable leader of the antismoking crusade throughout his professional career.

Review of coronary-subclavian steal following internal mammary artery-coronary artery bypass surgery.

The syndrome of coronary-subclavian steal through an internal mammary artery graft following coronary artery bypass grafting is rare. We are aware of only eight cases reported in the world literature. The cases of these 8 patients are reviewed, and the case of the ninth patient is described. All patients but 1 have been successfully managed by subclavian-carotid artery bypass.

Early experience with in situ saphenous vein grafts for severe ischemia of the lower extremity.

Based upon this group of 35 patients with a variety of vascular lesions, it would appear that the in situ saphenous vein technique is certainly, at least, a viable alternative to standard bypass techniques. It has been applied with equally encouraging results by several surgeons in a variety of clinical settings, all using the procedure for the first time in a learning phase. This technique may become the procedure of choice for the treatment of occlusive disease of the lower extremity in this difficult and challenging group of patients.