Learn it now, sing it later? Field and laboratory studies on song repertoire acquisition and song use in nightingales.

In many bird species, song changes with age. The mechanisms that account for such changes are only partially understood. Common nightingales Luscinia megarhynchos change the size and composition of their repertoire between their first and second breeding season. To inquire into mechanisms involved in such changes, we compared the singing of 1-year-old and older free-living nightingales. Older males have more song types in common than have 1-year olds. Certain song types frequently sung by older birds did not (or only rarely) occur in the repertoire of yearlings ('mature' song types). We conducted learning experiments with hand-reared nightingales to address reasons for the lack of mature song types. The acquisition success of mature songs was as good as that of control songs (commonly sung by both age groups). However, the analysis of song type use revealed that all yearlings sang common song types more often than mature types. This indicates that the absence of certain song types in the repertoires of free-living yearlings cannot be accounted for by learning and/or motor constraints during song learning. Moreover, our results suggest that in communication networks, animals may restrict the actual use of their signal repertoire to a certain subset depending on the context.

Risk for transmission of Naegleria fowleri from solid organ transplantation.

Primary amebic meningoencephalitis (PAM) caused by the free-living ameba (FLA) Naegleria fowleri is a rare but rapidly fatal disease of the central nervous system (CNS) affecting predominantly young, previously healthy persons. No effective chemotherapeutic prophylaxis or treatment has been identified. Recently, three transplant-associated clusters of encephalitis caused by another FLA, Balamuthia mandrillaris, have occurred, prompting questions regarding the suitability of extra-CNS solid organ transplantation from donors with PAM. During 1995-2012, 21 transplant recipients of solid organs donated by five patients with fatal cases of PAM were reported in the United States. None of the recipients developed PAM, and several recipients tested negative for N. fowleri by serology. However, historical PAM case reports and animal experiments with N. fowleri, combined with new postmortem findings from four patients with PAM, suggest that extra-CNS dissemination of N. fowleri can occur and might pose a risk for disease transmission via transplantation. The risks of transplantation with an organ possibly harboring N. fowleri should be carefully weighed for each individual recipient against the potentially greater risk of delaying transplantation while waiting for another suitable organ. In this article, we present a case series and review existing data to inform such risk assessments.

Imaging infection with LeuTech.

LeuTech is a 99Tcm labelled, anti-CD15, IgM, murine monoclonal antibody shown to have high affinity (Kd = 10(-11) M) for CD15 receptors (5.1 x 10(5)/cell) expressed on human neutrophils. LeuTech was injected directly, intravenously, and its efficacy in imaging infection in 46 consecutive patients was determined. Human anti-mouse antibody (HAMA) response was examined in 30 normal volunteers using a standard LeuTech dose reconstituted with decayed 99Tcm solution. There were 38 true positive, six true negative, and two false negative scans. Of the 38 positive images, 33 (92%) were positive within 10 min after injection of LeuTech. LeuTech accuracy in this group of patients was 96%, sensitivity 95%, specificity 100%, positive predictive value (PPV) 100%, and negative predictive value (NPV) 75%. No elevation of the HAMA titre was observed in any of the 30 normal volunteers and no adverse reaction was noted in any patient. LeuTech is a highly promising agent for rapid imaging of infectious foci.

Scintigraphic determination of equivocal appendicitis.

We evaluated Tc-99m-labeled anti-CD15 immunoglobulin M monoclonal antibody (LeuTech) for scintigraphic detection of acute appendicitis in patients with an equivocal clinical presentation. LeuTech avidly binds to circulating and sequestered human polymorphonuclear neutrophils in vivo eliminating the need for in vitro cell labeling and the risks of blood handling. We studied 99 patients to evaluate the safety and efficacy of LeuTech imaging. Serial dynamic and static planar images were acquired for up to 3 hours after the intravenous administration of 10 to 20 mCi of Tc-99m LeuTech. Scans were read as positive or negative for acute appendicitis or other intra-abdominal infection. The institutional diagnosis was established by surgery and histopathology of the appendix, results of other diagnostic studies, or 2-week clinical follow-up. Scans were positive for appendicitis in 39 of 40 patients with appendicitis at surgery (sensitivity 98%) and negative for appendicitis in 49 of 58 patients without appendicitis (specificity 84%). One was lost to follow-up. Accuracy, positive predictive value, and negative predictive value were 90, 81, and 98 per cent respectively. In patients with appendicitis and positive scans more than 50 per cent of the images were positive at 4 minutes, and all were positive by 1 hour. Mean time of first positive image was 15 minutes. There were no serious adverse reactions. We conclude that LeuTech imaging is a highly sensitive test for detection of appendicitis in equivocal cases. There are advantages of this agent over the other currently used radiotracers in terms of convenience and time to diagnosis particularly the rapidity with which acute appendicitis will be seen on the images.

Neutrophil-specific 99mTc-labeled anti-CD15 monoclonal antibody imaging for diagnosis of equivocal appendicitis.

UNLABELLED: We evaluated 99mTc-labeled anti-CD15 immunoglobulin M monoclonal antibody (LeuTech) for diagnosing acute appendicitis in patients with an equivocal clinical presentation. LeuTech avidly binds to circulating and sequestered human polymorphonuclear neutrophils in vivo, eliminating in vitro cell labeling and blood handling. METHODS: We studied 49 patients to evaluate the safety and efficacy of LeuTech imaging. 99mTc-labeled LeuTech was prepared on site using a lyophilized kit, 99mTc-labeled pertechnetate, and 2 different incubation techniques, 1 at room temperature and the other at 37 degrees C. The abdomen was serially imaged for up to 3 h after the intravenous administration of 370-740 MBq 99mTc-labeled LeuTech. Scans were read as positive or negative for acute appendicitis or other intraabdominal infection. The institutional diagnosis was established by surgery, other diagnostic studies, or 1-mo clinical follow-up. RESULTS: Scans were positive for appendicitis in all 26 patients with appendicitis, for a sensitivity of 100%, and negative for appendicitis in 19 of 23 patients without appendicitis, for a specificity of 83%. Accuracy, positive predictive value, and negative predictive value were 92%, 87%, and 100%, respectively. Results were not different between the LeuTech preparations. The rate of laparotomies with negative findings in patients who underwent surgery was 10%. The average time from injection to LeuTech visualization in the appendix for cases positive for appendicitis was 9 min. No serious adverse reactions occurred. CONCLUSION: LeuTech imaging is safe, rapid, and sensitive for diagnosis of appendicitis in equivocal cases. The potential advantages of LeuTech over currently available radiopharmaceuticals for infection imaging are ease of preparation, absence of blood handling, excellent image quality, no requirement for SPECT, and rapid diagnostic uptake.

The role of radiolabeled leukocyte imaging in the management of patients with acute appendicitis.

Acute appendicitis is a clinically challenging surgical disease particularly difficult to diagnosis in women and children. An atypical presentation of acute appendicitis is a major factor leading to delay in diagnosis and unnecessary surgery. Delay in diagnosis is associated with morbidity from perforation, abscess and prolonged hospitalization. The routine use of adjunctive imaging studies has not improved the diagnostic accuracy for acute appendicitis nor has impacted clinical outcome. 99mTc HMPAO-labeled leukocyte imaging is one diagnostic imaging test that has the potential of altering the clinical management of acute appendicitis. 99mTc HMPAO-labeled leukocyte imaging is highly sensitive for detecting even small inflammatory processes in the abdomen because of high target to background and early rapid uptake at sites of inflammation. We studied the use of 99mTc HMPAO-labeled leukocytes for diagnosis and management of suspected acute appendicitis in 124 patients with an atypical clinical presentation. Emergent imaging was performed immediately following injection of labeled leukocytes and continued until positive or through 2 hours if negative. The scan correctly and rapidly detected acute appendicitis in 50 of 51 patients with surgical confirmation for a sensitivity of 98%. The specificity was 82% leading to an overall accuracy of 90%. The high negative predicted value of 98% allowed early discharge from the emergency department and avoided costly observation in the hospital and potentially unnecessary surgery in these patients with negative scans. The negative exploratory laparotomy rate was 4% in this patient population compared to 9% in a similar population of patients who were not scanned. These data have been confirmed now in over 600 patients scanned in our department. The main drawbacks of 99mTc HMPAO-labeled leukocyte imaging are the requirement of blood handling and a delay in diagnosis because of the 2-hours preparation time prior to imaging. There are new radiopharmaceuticals on the horizon which have the potential of replacing 99mTc HMPAO-labeled leukocyte imaging and offer advantages of a shorter preparation time and no blood handling. These include 99mTc labeled monoclonal antibodies and chemotactic peptides. The 99mTc anti-SSEA-1 IgM antibody (LeuTech) is currently under investigation for use in acute appendicitis. In summary, nuclear medicine can play a key role in the diagnosis of acute appendicitis in patients with an atypical presentation. This technique is cost effective and appears to impact favorably on clinical outcome.

99mTc-hexamethylpropyleneamine oxime (Tc-WBC) scan for diagnosing acute appendicitis in children.

We used a radiolabeled white blood cell (WBC) scan as an adjunct to diagnose appendicitis in 100 children with equivocal signs or symptoms of appendicitis. WBC separation and labeling took 2 hours. Patients were imaged up to 3 hours after injection of labeled Tc-WBC. Accuracy was established in all 100 children by histopathological findings, medical records and follow-up interviews. Scans were positive in 40 and negative in 60. Positive scans averaged 76 +/- 40 minutes after injection (mean +/- SD); negative scans required 150-180 minutes. Tc-WBC scan correctly identified appendicitis in 36 of 37 children (sensitivity, 97%) and correctly excluded appendicitis in 59 of 63 (specificity, 94%). The false negative scan occurred in a patient whose perforated appendix was discovered at operation 3 days following the scan. Accuracy of the examination was 95 per cent, with a positive predictive value of 90 per cent and a negative predictive value of 98 per cent. The negative laparotomy rate for the entire group was 4 per cent. Tc-WBC imaging is an accurate, noninvasive test for ruling out appendicitis in children with right lower quadrant abdominal pain and equivocal presentation, although positive scans require more clinical judgment. The high sensitivity and negative predictive value suggest its potential for screening and discharging children from the emergency department.

Tc-99m-HMPAO white blood cell scan for diagnosis of acute appendicitis in patients with equivocal clinical presentation.

OBJECTIVE: The authors' goal was to evaluate the accuracy of Technetium 99m-HMPAO-labeled leukocyte imaging for screening patients with atypically presenting appendicitis and to determine how availability of this test affected practice patterns of surgeons at the authors' medical center. SUMMARY BACKGROUND DATA: Appendicitis can be difficult to diagnose and in equivocal cases usually requires inpatient observation. The delay may increase morbidity and costs. A test that rules out acute appendicitis could be cost effective if it allowed early discharge from the emergency department. Previously, there have been no simple, rapid, accurate noninvasive methods for improving diagnostic accuracy in patients with equivocal presentations of appendicitis. METHODS: Patients referred to rule out appendicitis were analyzed. Patients were imaged up to 3 hours after injection of 10-mCi 99mTc-HMPAO-labeled autologous leukocytes (Tc-WBC), and when the scans became positive, imaging was terminated and the requesting physician notified of the results. Diagnostic accuracy was established by surgical and histopathologic findings or by absence of symptoms after 1 month clinical follow-up. The source of referral, hospital length of stay, disposition of patients, and ancillary tests (ultrasound, computed tomographic scan, and barium enema) were analyzed. RESULTS: One hundred twenty-four patients were studied from November 1991 through December 1995. Fifty-eight percent of positive scans showed uptake within 1 hour of injection and 73% by 2 hours. The Tc-WBC scan correctly identified an inflammatory source of abdominal pain in 65 of 66 cases (sensitivity = 98%) and was correctly negative in 55 of 58 cases (specificity = 95%). The scan correctly diagnosed appendicitis in 50 of 51 cases (sensitivity = 98%) and correctly excluded appendicitis in 62 of 73 cases (specificity = 85%). Outpatient referrals increased from 38% to 87%. In those patients with negativescans, inpatient observation, number of adjunctive tests, and length of stay decreased significantly. CONCLUSIONS: The high sensitivity and negative predictive value of Tc-WBC imaging may permit patients to be screened and discharged from the emergency department. Focally positive scans often indicate disease requiring operation but not in all cases. The Tc-WBC imaging reduced the negative laparotomy rate to 3.9% while reducing admission rates and hospital length of stay.

Prevalence of aerobic bacteria in bronchoalveolar lavage fluids from healthy pigs.

Fiberoptic bronchoscopy was performed in pigs to assess bacterial contamination of bronchoalveolar lavage fluids (BALF) obtained by use of the method and to determine the aerobic bacterial species in bronchoalveolar airways of healthy pigs. Bacterial contamination of BALF caused by insertion of the bronchoscope was evaluated, using a chromogenic bacterial tracer strain, and was found to be 0.22% of total colony-forming units (CFU), with range between 0 and 1.6%. A total of 164 pulmonary-healthy pigs from 6 closed herds were selected. The BALF obtained from these pigs were examined bacteriologically. Bacteria could not be isolated from 10.4% of all BALF; 5.5% of the BALF samples yielded pure cultures; and 84.1% yielded mixed aerobic bacterial growth. In BALF from 29.2% of the pigs, < or = 5 x 10(2) CFU of bacteria/ml were isolated. The total number of bacteria in BALF from 50% of the pigs varied between 5 x 10(2) and 10(3) CFU/ml; 10.4% of BALF samples contained between 10(3) CFU/ml and 5 x 10(3) CFU/ml. More than 1 bacterial species were isolated from a single lung lavage of 84.1% of the pigs. Up to 6 species were isolated from a single BALF sample. A total of 443 bacterial isolates were differentiated into 25 bacterial genera and species. Samples of BALF yielded staphylococci (67.6%: Staphylococcus hyicus from 13.4% of the samples and S aureus from 2.4%), alpha-hemolytic streptococci (49.4%), Escherichia coli (42.1%), non-hemolytic streptococci (26.2%), Klebsiella spp (18.3%), micrococci (12.8%), and Coryneformes (11.0%). Other bacterial species were found, but less frequently.(ABSTRACT TRUNCATED AT 250 WORDS)

[Pneumonia diagnosis in living swine using lung lavage]. / Pneumoniediagnostik am lebenden Schwein mit Hilfe der Lungenspülung.

In pigs coming from fattening units with tenacious pneumonitis problems the attempt was made to find an etiological diagnosis in living pigs by bronchoalveolar lavage (BAL) and serological examinations on antibodies against Mycoplasma hyopneumonia, Actinobacillus pleuropneumoniae and Influenza-A-virus (serotypes H1N1 and H3N2). In some cases the results of the bacteriological examinations of the BAL were compared with the post mortem findings. Both methods yield similar results. Mycoplasma hyopneumonia could neither be cultured from the BAL nor indicated the results of the serological examinations infections with M. hyopneumoniae. Pasteurella multocida was isolated from 73% of the BAL-samples. Actinobacillus pleuropneumoniae was found in 4 from 90 samples. Positive antibody titers against Influenza-virus in most of the sera indicate that the clinical course of Influenza is changing from an acute epidemic to an enzootic disease in fattening units.

Gold-195m first-pass radionuclide ventriculography, thallium-201 single-photon emission CT, and 12-lead ECG stress testing as a combined procedure.

Graded, sequential, rest/exercise, gold-195m (Au-195m) (T1/2 = 30 seconds), first-pass ventriculography and thallium-201 (T1-201) single-photon emission computed tomography (SPECT) were performed simultaneously during a single, electrocardiograph-monitored, bicycle stress test in 24 individuals. The technical aspects and logistics involved in performing this combined radionuclide study are stressed in this preliminary report. Fourteen healthy volunteers each had a normal left ventricular ejection fraction and wall-motion response, along with normal Tl-201 perfusion and washout, as determined by both visual and quantitative analysis of the tomographic sections. Each of ten patients with coronary artery disease had at least one abnormality of these parameters. We suggest that it is technically feasible to evaluate both cardiac function and myocardial perfusion simultaneously by combining Au-195m ventriculography and T1-201 SPECT imaging into a single, noninvasive, diagnostic package.

Positive In-111 white cell scan in a patient with multiple metastases.

A case of increased uptake of In-111-labeled leukocytes in bony metastases from adenocarcinoma of the prostate is presented. Bone scintigraphy, subsequent to the white cell study, showed virtually identical abnormalities as the indium scan. Clinical course and laboratory data supported the diagnosis of widespread metastatic carcinoma. Although the exact cause(s) is unclear, possible mechanisms are discussed.

Indium-111-labeled leukocyte localization in hematomas: a pitfall in abscess detection.

Indium-111-labeled white-blood-cell scanning is a useful modality in abscess detection and has replaced gallium scanning in many institutions. Sensitivities of 72% to 90% and specificities of 90% to 100% have been reported. In searching for abscesses seven cases of indium-111-labeled leukocyte uptake were encountered in collections subsequently proved to be noninfected hematomas. Abundant red blood cells with few or no white blood cells, no bacteria, and a benign clinical course identified these noninfected hematomas. Five of the patients were being treated with hemodialysis and three were recent allograft recipients. The results indicate some limitation and nonspecificity in indium-111 scanning, despite its many benefits.

In-111-leukocyte scintigraphy for detection of infection associated with peritoneal dialysis catheters.

In-111-labeled leukocytes were administered to 13 patients on continuous ambulatory peritoneal dialysis in order to locate catheter-associated infections. Using a marker to indicate the catheter exit site, infections of the catheter tunnel were correctly identified prior to surgery in 4 patients with relapsing peritonitis and infections of the exit site were diagnosed in 5 out of 7 patients. There were no false positives or negatives as documented by surgery or follow-up. The authors conclude that In-111-leukocyte scintigraphy appears to be accurate in diagnosing peritoneal infections of the dialysis catheter tunnel.

Interleukin 2 deficiency is a common feature of autoimmune mice.

IL 2 production was studied in autoimmune mice to assess the role of this lymphokine in the pathogenesis of murine lupus. Spleen and lymph node cells from autoimmune-susceptible mice show an age-dependent loss in the ability to produce functional IL 2. This defect correlates with disease expression and is most severe in MLR/Mp-Ipr/Ipr mice. MLR/Mp-Ipr/Ipr thymocytes gradually lose responsiveness to IL 2 with age. These results suggest that the immunoregulatory abnormalities of autoimmune mice may be due in part to IL 2 deficiency.