Knowledge about AIDS and follow-up compliance in patients attending a sexually transmitted disease clinic in the highlands of Papua New Guinea.

In a survey of 300 consecutive new attenders at the Porgera Health Centre Sexually Transmitted Disease Clinic information was obtained regarding knowledge about AIDS from male and female attenders. The differences between the sexes regarding a variety of socioeconomic variables, knowledge about AIDS and their compliance to follow-up appointments were studied as well as possible relationships between these social variables and the degrees of AIDS knowledge and compliance. Males tended to originate from further afield, be more educated, be either in salaried employment or not working at all, and be single as compared to females. They also admitted to more extramarital sexual contacts and received more adequate treatment. Knowledge about AIDS was also significantly higher amongst male attenders and in this group was correlated strongly with overall educational attainment and employment status but did not show any relationship with the number of extramarital contacts admitted to. Only 9% of the patients knew about condoms and their role in prevention. Follow-up compliance was generally poor, and not significantly higher in those with higher scores of knowledge about AIDS, but showed a relationship with the type of disease being treated and with the ultimate adequacy of treatment received.

PIP: Gender differences in knowledge about AIDS and compliance with follow-up appointments were investigated in 300 consecutive new patients (176 men and 124 women) at the Porgera Health Center Sexually Transmitted Disease (STD) Clinic in the highlands of Papua New Guinea in 1992-93. The most common STDs diagnosed among men and women, respectively, were: gonorrhea (28% and 12%), donovanosis (30% and 24%), and nongonorrheal urethritis/pelvic inflammatory disease (20% and 56%). Compared to females, men tended to be from outside the district, have some formal education, be either unemployed or in a salaried position, and be single. 60% of male clients, compared with 10% of female clients, reported an extramarital sexual contact in the previous 3 months. 46% of male and 68% of female STD patients had either never heard of AIDS or knew the name only. Knowledge about AIDS was significantly higher among males and was associated with overall educational attainment and employment status. Only 9% of patients (14% of men and 1% of women) were aware of condoms and their role in STD prevention. Of the 230 clients scheduled for follow up, only 19% of males and 35% of females were fully compliant. Follow-up compliance was not associated with AIDS knowledge scores, but was related to the type of disease being treated and inadequate treatment. These findings suggest an urgent need for AIDS education and promotion of condom use (despite opposition from some Christian groups) in this area.

Radionuclide imaging of experimental atherosclerosis with nonspecific polyclonal immunoglobulin G.

The utility of nonspecific polyclonal IgG for external imaging of experimental atherosclerosis was tested in a series of rabbits after balloon catheter deendothelialization of the abdominal aorta. Following injection of 111In-IgG, 111In-Fc, or 111In-Fab serial images were recorded. In addition, several animals received 125I-low density lipoproteins [125I-LDL], or 125I human serum albumin [125I-HSA] as positive and negative controls. Forty-eight hours after injection of the radiolabeled proteins, the aortas were removed, divided into abdominal and thoracic regions, counted, and autoradiographed. The images acquired after injection of 111In-IgG and 111In-Fc, showed clear focal accumulation of radioactivity in the healing abdominal aorta. In contrast, the images obtained after injection of 111In-Fab did not show focal radionuclide accumulation. For 111In-IgG and 111In-Fc there were three to six times as many counts in the abdominal as in the thoracic aorta, while for 111In-Fab and 125I HSA, the abdominal and thoracic counts were nearly equal. The results suggest that radiolabeled IgG and Fc can be used to image experimental atherosclerosis.

Radiolabeled, nonspecific, polyclonal human immunoglobulin in the detection of focal inflammation by scintigraphy: comparison with gallium-67 citrate and technetium-99m-labeled albumin.

The accumulation of nonspecific polyclonal human immunoglobulin (IgG) radiolabeled with 125I or 111In was compared to that of [67Ga]citrate and [99mTc]albumin in rats with deep thigh inflammation due to Escherichia coli infection. Serial scintigrams were acquired at 1, 3, 24, and in some cases, 48 hr after injection. As early as 3 hr postinjection, [111In]IgG showed greater accumulation at the lesion than [99mTc]HSA (p less than 0.01). Both [125I]IgG and [111In]IgG showed greater accumulation than [67Ga]citrate (p less than 0.01). At 24 hr, IgG image definition increased, while HSA image definition decreased, and the intensity of accumulation of both IgG preparations was greater than that of [67Ga]citrate or [99mTc]HSA (p less than 0.01). At all imaging times, [67Ga]citrate accumulation was surprisingly low. In inflammation produced by Pseudomonas aeruginosa, Staphylococcus aureus, Klebsiella pneumoniae, Candida albicans, or turpentine, [111In]IgG accumulation was similar to the results obtained with Escherichia coli. These studies suggest that focal sites of inflammation can be detected with radiolabeled nonspecific human polyclonal IgG.

Detection of acute inflammation with 111In-labeled nonspecific polyclonal IgG.

The detection of focal sites of inflammation is an integral part of the clinical evaluation of the febrile patient. When anatomically distinct abscesses are present, lesion detection can be accomplished by standard radiographic techniques, particularly in patients with normal anatomy. At the phlegmon stage, however, and in patients who have undergone surgery, these techniques are considerably less effective. While radionuclide methods, such as Gallium-67 (67Ga)-citrate and Indium-111 (111In)-labeled WBCs have been relatively successful for the detection of early inflammation, neither approach is ideal. In the course of studies addressing the use of specific organism-directed antibodies for imaging experimental infections in animals, we observed that nonspecific polyclonal immunoglobulin G (IgG) localized as well as specific antibodies. Preliminary experiments suggested that the Fc portion of IgG is necessary for effective inflammation localization. Since polyclonal IgG in gram quantities has been safely used for therapy in patients with immune deficiency states, we decided to test whether milligram quantities of radiolabeled IgG could image focal sites of inflammation in humans. Thus far, we have studied a series of 84 patients with suspected lesions in the abdomen, pelvis, vascular grafts, lungs, or bones/joints. In 48 of 52 patients with focal lesions detected by surgery, computed tomography (CT), magnetic resonance imaging (MRI), or ultrasound (US), the IgG scan correctly localized the site, while 31 patients without focal inflammation had no abnormal focal localization of the radiopharmaceutical. Four patients had false negative scans and one patient had a false positive scan. For this small series, the overall sensitivity and specificity were 92% and 95%, respectively. In this report, we review our experience with this exciting new agent.

Imaging of complex NMR spectra.

The Point Spread Function (PSF) in NMR imaging is the result of both the line broadening due to magnet field inhomogeneity and the intrinsic spectrum of the nucleus at resonance. In the case of proton imaging, the line broadening dominates the small chemical shifts and the spectral lines are not resolved. This is not generally the case with other nuclei having strong chemical shifts and the PSF then has a complex structure. During imaging, the complex PSF is convolved with the spatial distribution of the nucleus at resonance and this leads to halo artifacts which are dependent on the imaging technique employed. The images due to the ensemble of spectral lines can be separated in principle by deconvolution of the data with the PSF before reconstruction. In the special case where the complex PSF is spatially independent, it can be obtained from the Free Induction Decay (FID) data produced in the absence of a spatially encoding gradient field. This technique has been successfully applied to in-vivo imaging of exogenous perfluorocarbon material.