AIDS mania

Twenty patients with HIV infection and mania were grouped according to whether their first manic episode occurred when CD4 count was < 200 (late onset) or > or = 200 (early onset). The late-onset patients were less likely to have personal or family histories of mood disorder and more likely to have dementia or cognitive slowing. They also exhibited a different manic symptom profile. The different sociodemographic and symptom profiles associated with early-onset and late-onset mania may reflect differences in pathophysiology.

B-scan ocular ultrasonography in preterm and term infants

PURPOSE

To evaluate the normal B-scan ocular ultrasonographic findings in preterm and term newborns. This information would be useful in making perinatal ocular diagnoses, especially in consideration of the rapidly changing eyes of normal infants shortly after birth.

METHODS

One hundred two healthy infants aged 28 to 48 weeks postconception were prospectively studied. Eighty-six had complete sonograms, while others had incomplete examinations due to systemic instability. B-scan ultrasonography was conducted through acoustic coupling medium and a closed eyelid using the Coopervision Ultrascan 404 unit. The ultrasound findings were evaluated relative to the infant's postconceptional age and weight at examination and the axial lengths of each eye. The ultrasonographer, who determined the presence of abnormal findings, was masked to the parameters mentioned above.

RESULTS

Four specific findings frequently were noted in newborns that would be considered abnormal in adult eyes. These were: 1) a visible Tenon's capsule; 2) prominent superior ophthalmic vein; 3) sonolucent extraocular muscles; and 4) vitreous opacities. These findings were more common in the more premature infants (P < 0.01 by t test).

CONCLUSIONS

The presence of these four ultrasonographic findings in the eyes of infants should be considered normal, and should not necessarily prompt further work up until after the perinatal period.

Psychiatric morbidity on entry to an HIV primary care clinic

OBJECTIVE

To ascertain the prevalence and predictors of psychiatric distress in an inner-city HIV primary care clinic.

DESIGN

Cross-sectional study.

SETTING

Inner-city adult HIV clinic.

PARTICIPANTS

A series of 222 HIV-infected patients newly presenting to the medical clinic for evaluation over a 1-year period.

OUTCOME MEASURES

A screening method, based on the General Health Questionnaire (GHQ) and the Beck Depression Inventory (BDI), whose sensitivity, specificity and positive predictive value for psychiatric diagnosis were previously established in this clinic.

RESULTS

Fifty-two per cent of participants scored above the screening threshold (i.e., scored > 14 on the BDI or > 6 on the GHQ). A comorbid substance use condition was the most powerful and consistent predictor of psychiatric distress (P < 0.05). Limited education and current unemployment contributed to higher scores on the BDI or the GHQ (P < 0.05). However, HIV illness variables and psychiatric personal or family histories were not significant predictors of psychiatric distress (P > 0.05 in all cases).

CONCLUSIONS

Rates of psychiatric distress in inner-city adult HIV clinics are much higher than in the general population or than in other outpatient medical clinics. They are also not associated with what most clinicians perceive as traditional risk groups such as psychiatric histories and social disadvantage. These findings support the position that easy access to psychiatric care is essential to HIV clinics.

Health care focus documentation--more efficient charting

A revised nursing documentation system is now user-friendly, multi-disciplinary and computer adaptable. Sixteen health care focus topics replaced nursing diagnoses and served as a common thread to coordinate documentation of patient care.

Psychiatric issues and emergencies in HIV infection

Emergency departments are frequently the entry point for patients infected with HIV. Psychiatric conditions may be the initial predominant presentation or an important concomitant factor. Because of the complexities of HIV infection, the serious medical nature of its associated psychiatric complications, the frequent presence of comorbid substance use and other behavioral disorders, and the multiple sites of treatment involved, psychiatrists, emergency physicians, and other professionals must work in collaboration in screening patients infected with HIV for mental disorders and in providing careful and rational care.

TNF induction of EL4 hyposensitivity to lysis by recombinant (soluble) and membrane-associated TNFs: TNF binding, internalization, and degradation

EL4 mouse thymoma cells sensitive to TNF-mediated lysis only in the presence of cycloheximide (S-EL4) or in the presence or absence of cycloheximide (N-EL4) were used in these experiments. Murine tumor cell line (S-EL4) sensitivity to TNF cytotoxicity is augmented when cycloheximide is added together with TNF or when cycloheximide is added 1 hr before or after TNF. No enhanced sensitivity is observed when target cells are incubated with cycloheximide 2-4 hr before or after the addition of TNF. In the absence of cycloheximide, S-EL4 cells preexposed to murine TNF are less susceptible to lysis by TNF and TNF receptor-conjugated TNF but are lysed by integral membrane TNF. TNF-induced hyposensitivity is partially reversed by actinomycin D or by culturing the preexposed cells for 4 hr prior to TNF lytic assay. TNF preincubation of N- and S-EL4 cells results in an immediate decrease in 125I-TNF binding due to TNF receptor occupancy. Recovery of TNF-R occupancy and TNF internalization were subsequently noted.

Screening for psychiatric morbidity in a medical outpatient clinic for HIV infection: the need for a psychiatric presence

OBJECTIVE

To ascertain the prevalence and type of psychiatric morbidity present in HIV infected patients presenting for the first time to a specialty HIV medical clinic. Also, to develop a way of screening for psychiatric cases in this setting using established self-report questionnaires.

METHOD

Fifty patients who presented consecutively for medical care at the Johns Hopkins Hospital General HIV Clinic participated in this study. These patients were first screened using the General Health Questionnaire and the Beck Depression Inventory and subsequently underwent a comprehensive neuropsychiatric evaluation.

RESULTS

Fifty-four percent were found to suffer from a psychiatric disorder with an additional 22 percent from an active substance use disorder. These rates are one-and-one-half to two times higher than those reported from other medical clinics. The GHQ and BDI used together as screens could identify psychiatric "cases" with a sensitivity of 81 percent and a specificity of 61 percent, an efficacy similar to that found in other clinics.

CONCLUSIONS

Given the high prevalence of psychiatric disorders in HIV infected patients presenting for medical care, screening, evaluating, and treating for these disorders is crucial and should be pursued systematically. This is best done through the presence of a psychiatric team within HIV medical clinics rather than in affiliation with such clinics.

TNF receptor involvement in TNF-mediated activities against syngeneic malignant and normal mouse thymocytes

Receptor-dependent tumor necrosis factor (TNF)-mediated activities against mouse thymoma cells and normal thymocytes syngeneic for C57 mice were examined to determine the specific involvement of TNF receptors R1 and R2. Both receptors are expressed by EL4 thymoma cells and normal C57 thymocytes. TNF-mediated activities included (a) cytotoxicity, (b) induction of hyposensitivity to TNF-mediated lysis, (c) costimulatory stimulation of thymocyte proliferation, and (d) activation of NF-kB-like transcription factor. The ability of polyclonal antisera against TNF receptors to mimic the above TNF-mediated activities was determined. The results clearly showed that anti-TNF-R1 antibodies were cytotoxic against EL4 cells, induced hyposensitivity of S-EL4 to TNF lysis and activated the NF-kB-like transcription factor in EL 4 cells and syngeneic normal thymocytes. Antisera against TNF-R2 only mimicked TNF-mediated costimulation of thymocyte proliferation with IL2. No direct correlation was noted between TNF activation of NF-kB and TNF-mediated lysis.

Intramolecular dynamics in the environment of the single tryptophan residue in staphylococcal nuclease

The dipole relaxational dynamics in the environment of a single tryptophan residue Trp-140 in staphylococcal nuclease was studied by time-resolved (multi-frequency phase-modulation) spectroscopy and selective red-edge excitation. The long-wavelength position of the fluorescence spectrum (at 343 nm) and the absence of red-edge excitation effects at 0 and 20 degrees C indicate that this residue is surrounded by very mobile protein groups which relax on the subnanosecond time scale. For these temperatures (0-20 degrees C) the steady-state emission spectra did not show the excitation-wavelength dependent shifts (red-edge effects) for excitation wavelengths from 295 to 308 nm; however, the anisotropy decay rate is slow (tens of nanoseconds). This suggests that the spectral relaxation is due to mobility of the surrounding groups rather than the motion of the tryptophan itself. The motions of the tryptophan surrounding are substantially retarded at reduced temperatures in viscous solvent (60% glycerol). The temperature dependence of the difference in position of fluorescence spectra at excitation wavelengths 295 and 305 nm demonstrate the existence of red-edge effect at sub-zero temperatures, reaching a maximum value at -50 degrees C, where the steady-state emission spectrum is shifted to 332 nm. The excitation and emission wavelength dependence of multi-frequency phase-modulation data at the half-transition point (-40 degrees C) demonstrates the existence of the nanosecond dipolar relaxations. At -40 degrees C the time-dependent spectral shift is close to monoexponential with the relaxation time of 1.4 ns.

Divergence between cytotoxic effector function and tumor necrosis factor alpha production for inflammatory CD4+ T cells from mice with Sendai virus pneumonia

Sendai virus pneumonia in beta 2-microglobulin-deficient [beta 2-m(-/-)] mice lacking CD8+ T cells is characterized by the development of CD4+ cytotoxic T lymphocytes that can be recovered directly from the respiratory tract. These CD4+ cytotoxic T lymphocytes are not found in beta 2-m (+/+) mice, though inflammatory CD4+ T cells from both beta 2-m (-/-) and beta 2-m (+/+) mice produce substantial amounts of tumor necrosis factor alpha. Blocking experiments with a monoclonal antibody that also inhibits tumor necrosis factor beta show that the secreted forms of these two cytokines are not responsible for virus-specific killing of class II major histocompatibility complex-compatible targets. Comparison of electron micrographs indicates that the CD4+ effectors from the beta 2-m (-/-) mice are potent inducers of apoptosis, while this is not the case for the beta 2-m (+/+) CD4+ set. These experiments further define the functional status of virus-specific CD4+ T cells responding in vivo in the presence or absence of CD8+ effectors.

Psychiatric care for patients with HIV infection. The varying perspectives

This article reviews the literature on the classification and treatment of psychiatric morbidity associated with infection from the human immunodeficiency virus (HIV). The psychiatric disorders seen in HIV-infected patients are formulated by using one of the following four perspectives as treatment guides: 1) the syndromal or disease perspective, 2) the dispositional or personality perspective, 3) the behavioral or addictive perspective, and 4) the life story perspective.

Manic syndrome early and late in the course of HIV

In a chart review at a hospital's infectious disease AIDS clinic, manic syndromes affected 8% of patients who had AIDS. Of the 14 patients with manic episodes, those without a family or personal history of mood disorder presented later in the course of HIV infection and had a higher prevalence of comorbid dementia.

Neurologic complications of heart transplantation in children

Neurologic complications can add significant morbidity to otherwise successful orthotopic heart transplantations in children. Complications have been reported to occur in up to 50% of children undergoing heart transplantation. The purpose of this study was to identify the prevalence and outcome of neurologic complications of heart transplantation in children. We reviewed all children who received orthotopic heart transplantation at Texas Children's Hospital from November 1984 to November 1990. Twenty-two patients (ages, 3 weeks to 17 years; mean, 8.5 years) underwent heart transplantation using cardiopulmonary bypass with moderate hypothermia. For analysis, we compared results during the first 3 years of our experience, 1984 through 1987 (group 1), to 1987 through 1990 (group 2). Survival was 45% (5 of 11 patients) for group 1 and 73% (8 of 11 patients) for group 2. A neurologic complication was defined as a change in the neurologic examination and/or status. Neurologic complications included seizures (6 of 22 patients), strokes (3 of 22 patients), unresponsiveness (3 of 22 patients), and change in mental status (2 of 22 patients). Early (within 2 weeks after operation) neurologic complications occurred in 45% (10 of 22 patients), were persistent (sequelae lasting more than 4 months) in 27% (6 of 22 patients), and resulted in death in 9% (2 of 22 patients). Late (after 2 weeks after operation) neurologic complications occurred in 23% (5 of 22 patients), were persistent in 9% (2 of 22 patients), and have occurred in only two survivors. Neurologic factors were not responsible for the cause of death in group 2. No neurologic complications (early or late) were seen in 1 of 11 patients in group 1 as compared with 7 of 11 patients in group 2 (p < 0.015). Serious neurologic morbidity decreased between the two groups after preoperative cyclosporine was avoided and postoperative hypertension was controlled. All survivors are functioning at age-appropriate levels. Although neurologic complications may be frequent, long-term neurologic disability in survivors is rare.

Endophthalmitis in a patient with disseminated cryptococcosis and AIDS who was treated with itraconazole

We report a case of presumed cryptococcal endophthalmitis that occurred in a patient with severe disseminated cryptococcosis and AIDS. Multiple small, spherical lesions appeared bilaterally on the surface of the retina 2 weeks after cryptococcal meningitis was diagnosed; the lesions were associated with multiple blind spots, blurred vision, and the perception of flaring of light. Over the next week, many more lesions with adjacent hemorrhages appeared. Therapy with itraconazole over the next 3 months resulted in complete resolution of the lesions. Cryptococcal endophthalmitis is a rare disease. Fewer than 20 cases, including five in patients with AIDS, have previously been reported. None of these patients regained normal vision.

Cytolytic activities of activated macrophages versus paraformaldehyde-fixed macrophages; soluble versus membrane-associated TNF

Membrane-associated tumor necrosis factor (TNF) and soluble TNF were compared as to their lytic activities, and as to the kinetics of their expression by macrophages activated with LPS and/or IFN-gamma in the presence or absence of cycloheximide. EL 4 tumor cells, resistant and sensitive to lysis by recombinant TNF or membrane-associated TNF (paraformaldehyde (PF)-fixed activated macrophages) were used as targets. In the presence of cycloheximide the TNF-resistant S-EL4 cells were lysed by both TNFs. PF-fixed macrophages was cytolytic after 1 hr activation but not after 3 or more hours of activation. Their activity was totally inhibited by anti-TNF antibodies and was a composite of transmembrane (integral) TNF and soluble TNF conjugated to macrophage membrane TNF receptors. Treatment of the macrophages with glycine pH 3.0 buffer dissociated the conjugated TNF without affecting the integral membrane TNF. When macrophages were activated with LPS +/- IFN-gamma in the presence of cycloheximide or activated just with IFN-gamma their activity after fixation with paraformaldehyde was no longer detected. Nonfixed macrophages under these conditions still remained cytotoxic. Tumor cell susceptibility to membrane-associated TNF activity, in contrast to recombinant (soluble) TNF, was greatly reduced in the presence of nicotinamide, an inhibitor of ADP-ribosyltransferase, suggesting that the mechanisms of lysis by these TNFs may be different. The lytic activity of both TNFs was found to be receptor-dependent in that tumor cells, whose TNF binding sites were "down-regulated" by TPA, were rendered resistant to lysis by both membrane-associated and soluble TNFs.

Tumor necrosis factor-alpha analyzed within individual macrophages by combined immunocytochemistry and computer-aided image analysis

Immunocytochemical staining procedures were combined with computer-aided image analysis to quantitate the relative intracellular production of tumor necrosis factor-alpha (TNF) within individual macrophages. Optimal conditions for time and methods for the activation of TNF production, fixation of cells for optimal immunocytochemical staining, and image analysis methods were determined. Thioglycolate elicited peritoneal macrophages were readily activated to significantly increased levels of intracellular TNF, as early as 1 hr after activation with lypopolysaccharide (LPS) + interferon-gamma: maximum intracellular TNF was evident after 2-3 hr. Both LPS and interferon-gamma was necessary to increase intracellular TNF. Normal alveolar macrophages also readily produced increased intracellular TNF, but normal peritoneal and splenic macrophages were poorly activated to TNF production. Acid stripping of receptor bound TNF allowed discrimination between intracellular TNF/integral membrane TNF, and TNF-receptor-bound TNF. Results stress the importance of studying these TNF forms early after activation. Applications for TNF quantitation by these means are discussed.

Binding of polymyxin B to rat alveolar macrophages

The specific binding of radiolabeled polymyxin B (PmB) to rat alveolar macrophages was investigated. PmB retained its ability to inhibit lipopolysaccharide-induced tumor necrosis factor production by macrophages as long as one of five amino groups on PmB was unbound. Binding was saturable and temperature- and time-dependent, reaching steady state by 30 min at 37 degrees C and by 18 h at 4 degrees C. Macrophages had approximately 1.6 X 10(7) (Kd = 0.28 nM) PmB binding sites per cell. Lipid A had no appreciable effect on the number of sites. Binding did not occur to rat platelets, L929 fibroblast cells, a rat thymoma cell line, or precursor monocytic and myeloid cell lines. Precursor cells activated with 12-O-tetradecanoylphorbol-13-acetate acquired binding similar to that seen in alveolar macrophages, but L929 fibroblasts did not. Binding sites were sensitive to trypsin but not to phospholipase C. PmB may interact with specific binding sites involved in lipopolysaccharide-induced activation, production, or release of tumor necrosis factor by macrophages, inhibiting the effects of lipopolysaccharide on macrophages.

TPA induction of EL4 resistance to macrophage-released TNF: role of ADP-ribosylation in tumoricidal activities of TNF and other factors

Activated macrophages synthesize and release numerous tumoricidal soluble factors that can be divided into receptor- or nonreceptor-dependent agents. Tumor necrosis factor (TNF) would be an example of the former. In our experimental model the killing of EL4 thymoma cells by syngeneic activated macrophages involves, but not exclusively, TNF. Our results show that approximately 50% of the anti-EL4 activity expressed by macrophages can be specifically inhibited with rabbit anti-mouse TNF antibody. EL4 variants resistant to the lytic activity of TNF were still susceptible to macrophage-mediated lysis. A tumor-promoting phorbol ester, TPA, rendered TNF-sensitive and -insensitive EL4 cells resistant to M phi-mediated lysis. However, TPA down-regulated TNF-specific binding sites on both TNF-sensitive and -resistant cell surface membranes, suggesting that resistance to TNF involves postligand:receptor events. Tumor cell G-protein involvement (ADP-ribosylation), as a result of TNF-TNF receptor interactions, was investigated. The results showed that pertussis toxin was cytotoxic against TNF-sensitive and -resistant EL4 cells but not against TPA-treated target cells. Inhibitors of ADP-ribosyltransferase inhibited pertussis toxin cytotoxicity and macrophage-mediated lysis but did not interfere with recombinant TNF lytic activity.

Polymyxin B prevents lipopolysaccharide-induced release of tumor necrosis factor-alpha from alveolar macrophages

Polymyxin B (PmB) blocks many of the toxic effects of lipopolysaccharide by mechanisms that are not yet understood. The production of tumor necrosis factor-alpha (TNF-alpha) by isolated rat alveolar macrophages in response to lipopolysaccharide and macrophage-activating factor was blocked by PmB at concentrations of 100, 10, and 1 micrograms/ml. Gentamicin enhanced rather than inhibited TNF production at the 100-micrograms/ml concentrations and had no effect at low concentration. Similar inhibitory effects were induced by PmB in an in vivo model in which rat macrophage TNF production was stimulated by intratracheally injected lipopolysaccharide. Because many of the effects of lipopolysaccharide are mediated by TNF, this inhibition provides a mechanism to explain the protection afforded by PmB against lipopolysaccharide-induced toxicity.

Human macular pigment assessed by imaging fundus reflectometry

A computerized, television-based, imaging fundus reflectometer was used to obtain estimates of the spatial distribution of macular pigment (xanthophylls) from seven normal subjects. Digitized images of the bleached macula of each subject were acquired at illuminating wavelengths from 462 to 697 nm. An analysis of spectral reflectances indicated that differences in short-wavelength reflectance between the foveal center and parafovea were influenced by spatial variations in melanin and oxyhemoglobin absorption as well as by the distribution of macular pigment. To provide an estimate of the spatial distribution of macular pigment alone, we have corrected fundus images obtained at 462 nm for the effect of melanin and oxyhemoglobin absorption. The spatial variation in macular pigment double density across the horizontal and vertical meridians of the retina was well described by Gaussian functions. The peak double densities for the individual subjects ranged from 0.22 to 0.45 and the standard deviations of the Gaussian functions averaged approx. 1 degree.

The effect of phorbol esters on tumor cell sensitivity to macrophage-mediated cytostasis

Macrophage-mediated cytostasis was measured in a mouse syngeneic system where EL4 thymoma cells were found to be inhibited by C57B1/6 mouse macrophages. When tumor cells were pretreated with TPA, they became resistant to macrophage-mediated stasis. Nonelutriated as well as elutriated cells enriched in G1/early S and late S were sensitive to macrophage-mediated stasis. However, when elutriated cells were treated with TPA, cells enriched in G1/early S were rendered resistant to the cytostatic activity of macrophages whereas cells enriched in late S were not. The TPA effect on tumor cell susceptibility to stasis was found to be reversible and a nontumor-promoting phorbol ester, alpha-PDD, was ineffective.

Induction of EL4 cell resistance to syngeneic macrophage-mediated lysis by protein kinase C ligands; effects of cultured TPA-treated target cell and protein phosphorylation

Pretreatment of EL4 cells with 12-O-tetradecanoyl phorbol-13-acetate (TPA) for 30 min renders them resistant to lysis by activated macrophages (M phi). This resistance was augmented two to three-fold when TPA-treated EL4 cells were incubated for 2-6 hr prior to co-culture with M phi. Preincubation of TPA-treated cells for 24 hr could result in 100% resistance. in this paper we show that an endogenous ligand for protein kinase C, oleoyl-2-acetate glycerol (OAG), was capable of inducing tumour cell resistance to M phi kill and, similar to the effects seen with TPA, OAG did not affect the selective binding of tumour cells to activated M phi. Another important observation on the mechanism of TPA induction of tumour cell resistance was that once the target cells were programmed to die after a minimal contact with activated M phi of 4-6 hr, TPA treatment was ineffective in altering the percent lysis 20 hr later. To investigate whether any possible correlation exists between TPA-induced protein phosphorylation and acquisition of resistance, EL4 cells were labelled with 32P and treated simultaneously with TPA, and cellular proteins were resolved by two-dimensional gel electrophoresis. Eight polypeptides (MW 24,000-70,000, pI 4.8-6.1) showed consistent increased phosphorylation as a result of TPA treatment. One-minute exposure with TPA resulted in enhanced phosphorylation of only four peptides (MW 39,000, 58,000, 63,000, 70,000) while all eight polypeptides showed increased phosphorylation by 10 min.

Effects of maternal hydration on fetal renal pyelectasis

Fetal renal pyelectasis is a frequent finding on routine obstetrical sonography. The cause of this pelvocalyceal dilatation is often not apparent, although urinary tract obstruction is the most important condition to be excluded. One of the many hypothetical explanations for minimal fetal renal pyelectasis suggests that aggressive maternal hydration before sonography leads to fetal diuresis with resultant pelvocalyceal dilatation. In this study, 20 pregnant volunteers underwent sonography after 10-12 hours of dehydration, after which 1,000 ml of fluid was administered and repeat sonography was performed. Despite a significant increase in the state of maternal hydration as determined by a decrease in urine specific gravity, there was no significant change in the degree of fetal renal pyelectasis before and after hydration. Therefore, pelvocalyceal dilatation identified prenatally should not be attributed to maternal hydration.

Macular pigment and reduced foveal short-wavelength sensitivity in retinitis pigmentosa

Some patients with retinitis pigmentosa (RP) show a reduced foveal short-wavelength sensitivity that cannot be attributed to a reduction in the sensitivity of the short-wavelength cone system. To determine whether an increased amount of macular pigment (xanthophyll) might account for this finding, we derived estimates of the two-way optical density of the macular pigment of five such RP patients as well as of five normals. The spectral reflectance of the foveal region of each subject was obtained from digitized images of the bleached fundus provided by a television-based reflectometer. The density spectra of the macular pigment, melanin, and oxygenated hemoglobin were fit by a least-squares procedure to the log of the ratio of parafoveal to foveal spectral reflectance in order to obtain a quantitative estimate of the contribution of each of these ocular pigments to foveal short-wavelength reflectance. By this analysis, the two-way densities of the macular pigment, melanin, and oxyhemoglobin of the RP patients were not significantly different from those of the normals. Therefore, the reduced foveal short-wavelength sensitivity of these patients was not due to an increased amount of macular pigment, but may result instead from morphological abnormalities in the foveal cones such that a normal amount of macular pigment screens the cones more effectively.

Painful sickle cell crisis: bone marrow patterns observed with MR imaging

Eleven patients with homozygous sickle cell anemia (SCA) undergoing painful crisis were studied with magnetic resonance (MR) imaging. The signal intensity of bone marrow was diffusely decreased in the axial and peripheral skeleton on short repetition time (TR)/echo time (TE) images and long TR/TE images, which suggested hematopoietic marrow hyperplasia and was confirmed by isotope marrow scans in five patients. Focal areas of further decrease in signal intensity were seen on short TR/TE images in 12 of the 14 (86%) painful joints and three of the five (60%) painless joints. In the painful joints, these focal areas converted to high signal intensity on long TR/TE images, presumably due to edema, which suggested acute marrow infarction. In the painless joints, these low-intensity focal areas remained as low signal on long TR/TE images, which suggested absence of edema and thus areas of old infarction or fibrosis. These results indicate that MR imaging may enable differentiation between acute and chronic marrow infarcts in patients with SCA and serve as a useful guide in monitoring and directing therapy.

Cardiac MR imaging in Pompe disease

The magnetic resonance (MR) imaging findings in a 5-month-old infant with glycogen storage disease of the heart revealed hypertrophy of the right and left ventricles and the interventricular septum with an irregular inhomogeneous appearance of the myocardium. The descriptive features of the MR study are correlated with cardiac angiography and echocardiography in Pompe disease.

Oxidation of chloride and thiocyanate by isolated leukocytes

Peroxidase-catalyzed oxidation of chloride (Cl-) and thiocyanate (SCN-) was studied using neutrophils from human blood and eosinophils and macrophages from rat peritoneal exudates. The aims were to determine whether Cl- or SCN- is preferentially oxidized and whether leukocytes oxidize SCN- to the antimicrobial oxidizing agent hypothiocyanite (OSCN-). Stimulated neutrophils produced H2O2 and secreted myeloperoxidase. Under conditions similar to those in plasma (0.14 M Cl-, 0.02-0.12 mM SCN-), myeloperoxidase catalyzed the oxidation of Cl- to hypochlorous acid (HOCl), which reacted with ammonia and amines to yield chloramines. HOCl and chloramines reacted with SCN- to yield products without oxidizing activity, so that high SCN- blocked accumulation of chloramines in the extracellular medium. Under conditions similar to those in saliva and the surface of the oral mucosa (20 mM Cl-, 0.1-3 mM SCN-), myeloperoxidase catalyzed the oxidation of SCN- to OSCN-, which accumulated in the medium to concentrations of up to 40-70 microM. Sulfonamide compounds increased the yield of stable oxidants to 0.2-0.3 mM by reacting with OSCN- to yield derivatives analogous to chloramines. Stimulated eosinophils produced H2O2 and secreted eosinophil peroxidase, which catalyzed the oxidation of SCN- to OSCN- regardless of Cl- concentration. Stimulated macrophages produced H2O2 but had low peroxidase activity. OSCN- was produced when SCN- was 0.1 mM or higher and myeloperoxidase, eosinophil peroxidase, or lactoperoxidase was added. The results indicate that SCN- rather than Cl- may be the physiologic substrate (electron donor) for eosinophil peroxidase and that OSCN- may contribute to leukocyte antimicrobial activity under conditions that favor oxidation of SCN- rather than Cl-.

Induction of tumor cell resistance to macrophage-mediated lysis by phorbol esters: a postbinding event

Activated macrophages can recognize, bind to, and lyse tumor cells in an antibody-independent manner. We have found that tumor cells pretreated with phorbol esters are markedly less susceptible to macrophage-mediated cytolysis, although the initial binding step is unaffected. Tumor cells preincubated with tumor-promoting phorbol esters (10(-8)-10(-6) M) were rendered resistant to macrophage kill whereas non-tumor-promoting derivatives were inactive in protecting tumor cells against cytolysis. Inhibition of [3H]phorbol-12,13-dibutyrate binding by other phorbol esters correlated with their potency as tumor promoters and their ability to render tumor cells resistant to macrophage killing. The role of protein kinase C as the receptor to phorbol esters was implicated by inhibition of PDBu binding by phenothiazine derivatives. This suggests a possible mechanism for the resistance of phorbol ester-treated tumor cells to macrophage-mediated cytolysis.

Induction of tumor cell resistance to macrophage-mediated lysis by preexposure to non-activated macrophages

Thioglycollate-elicited peritoneal exudate (non-activated) macrophages do not lyse tumor cells and in contrast to activated macrophages bind less target cells. However, a non-lethal encounter of tumor cells with non-activated macrophages resulted in a pronounced effect on the subsequent tumor cell binding to and lysis by activated macrophages. Our results have shown that binding of tumor cells by non-activated macrophages was Ca2+ and temperature dependent; had a requirement for a Pronase-sensitive structure on macrophage surface membranes; was saturable; and was 2-3X less than that observed for activated macrophages. Experiments were conducted in which syngeneic tumor cells were incubated with a monolayer of non-activated macrophages and then assayed for selective binding and sensitivity to lysis. The important observations were that as a result of a 3-hr incubation with non-activated macrophages at an EC: TC ratio of 5:1 there was an increase in the number of tumor cells that bound to both activated and non-activated macrophages; a loss of selective binding in which the ratio of tumor cells bound to activated/non-activated macrophages (normally greater than 2) was lowered to 1.0; and a concomitant decrease in the susceptibility of tumor cells to macrophage-mediated cytolysis. The induction of tumor cell resistance to macrophage kill required an exposure to an excess number of non-activated macrophages, was reversible upon culturing with or without macrophages for 24 hr and required cell-cell contact. Our results reinforce the importance of selective binding between tumor cells and activated macrophages as an initial phase in tumor cell killing and also illustrates an active role for non-activated macrophages in vivo in allowing tumor cells to escape the immune surveillance by activated macrophages.

Microbial adherence and infection--clinical relevance

Adherence mechanisms have been described for some microbes, often in direct association with onset of infection. In other cases, the evidence is vague. This article will summarize modes of attachment, and will focus on each anatomical tract in an effort to outline the relationship between microbial adherence, host cells, foreign bodies, and infection.

Foveal cone pigment density difference and reflectance in retinitis pigmentosa

Cone pigment density difference refers to a change in light absorption by cones before and after bleaching of their visual pigments. With a television ophthalmoscope image processor, we measured the foveal cone pigment density difference in patients with retinitis pigmentosa (RP), good central vision, and no clinically apparent foveal lesion. Foveal reflectance was obtained at 12 different wavelengths of illumination. Compared with similar-aged normal subjects, most patients with dominantly inherited RP had normal or minimally reduced cone pigment density difference within the central fovea, relatively lower than normal density difference at the foveal margin, and increased foveal reflectance. Compared with these normal subjects, patients with recessively inherited RP had significantly reduced cone pigment density difference within the central fovea, relatively more normal density difference at the foveal margin, and normal foveal reflectance.

Foveal cone pigment density difference in the aging human eye

Using fundus reflectometry, we have measured a decrease in the density difference of the foveal cone visual pigments with age in human subjects. This decrease is consistent with a loss of visual pigment in the retina with age. Fundus reflectance and normalized density difference spectra data are presented for these subjects. A decrease in cone pigment with age would be consistent with both anatomic studies, which indicate a loss and displacement of photoreceptors with age, and psychophysical studies, which demonstrate loss of photoreceptor function with age.

Failure of sulfites to produce clinical responses in patients with systemic mastocytosis or recurrent anaphylaxis: results of a single-blind study

Although sulfite sensitivity can precipitate asthma in a subpopulation of subjects with asthma, its role in precipitating anaphylaxis or as a nonspecific mast cell degranulator in systemic mastocytosis has not been examined. To evaluate critically the importance of sulfites in these diseases, eight patients with systemic mastocytosis and 25 patients with unexplained, recurrent anaphylaxis were challenged in a single-blind fashion; sodium bisulfite in capsules was administered in increasing doses of 1, 5, 10, 25, 50, 100, and 200 mg every 30 minutes. On separate occasions a liquid suspension of 200 mg of sodium bisulfite was administered to one patient with systemic mastocytosis and nine patients with anaphylaxis. Vital signs, pulmonary function tests, plasma histamine levels, and clinical reactions were monitored. There were no observable responses in either the mastocytosis group or in 23 of 25 patients in the anaphylaxis group. Two patients in the anaphylaxis group with initial positive challenges had similar symptoms on subsequent placebo challenge. One subject with asthma and with a history suggestive of sulfite sensitivity responded to oral challenge with 5 mg of sodium bisulfite and 100 micrograms of sodium bisulfite intradermally with a dramatic reduction in FEV, requiring treatment with bronchodilators. A comparison of baseline plasma histamine levels with those obtained after the sulfite challenge procedure in each category demonstrated a significant rise (p less than 0.05) in the systemic mastocytosis group. The overall level of significance determined by applying paired sample t tests to the histamine data from all subjects was p less than 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)

Needle punctures--documentation and incidence rate calculation

Potential hazards of puncture wounds have been well-defined and include transmission of hepatitis B virus, acquired immunodeficiency syndrome, syphilis, malaria, and other infectious diseases. Yet, standard methodology has not been used for statistical comparison. Attack rates have been expressed as needlesticks per full-time equivalents, needlesticks per employee per year, punctures per number of personnel, or punctures per number of hospital beds. These calculations do not account for the amount of time during which an employee is at risk of receiving a needle puncture. Also, numbers alone cannot account for intensity of care, potential exposures, or hours at risk. Nor can numbers provide an estimate of potential risk. A rate is more valuable than numbers because it measures the probability of occurrence. A meaningful incidence rate would be based on uniform data collection and would provide the number of puncture wounds per year for a standardized work period. This is similar in concept to nosocomial infections per patient-days of exposure. We propose the application of standard labor statistics methodology which accounts for man-hours worked, can be readily obtained in health care facilities, and can be modified as described here.

Increased adenosine deaminase (ADA) activity and a shift from ADA-dependent to ADA-independent phases during T-cell activation: a paradox

During activation of WF rat splenic T-cells, a change occurs with respect to susceptibility to a toxic accumulation of adenosine or deoxyadenosine (dADO) in the presence of adenosine deaminase (ADA) blockade. Addition of nucleoside 1 hour after the initiation of a concanavalin A response in the presence of 2'deoxycoformycin (DCF) markedly inhibited the response, whereas delay of addition of the nucleoside for 24-48 hours resulted in minimal or no inhibition. Inhibition was not simply the result of prolonged incubation of cells in the presence of nucleoside and was apparently not attributable to an effect on proliferating cells. Addition of interleukin 2 (IL-2) to cultures containing DCF and dADO did not reverse the inhibitory effect, which suggests that IL-2-producing T-cells also were not the target of nucleoside toxicity. A twofold increase in ADA activity that occurred during T-cell activation was nonessential for the survival of mitogen-activated T-cells in the presence of toxic concentrations of dADO and did not account for an apparent increased resistance of these cells to nucleoside toxicity. These paradoxical observations prompted an analysis of ADA activity in various populations of activated T-cells enriched with cells in G0/G1, S, or G2+M cell-cycle phases, which indicated that increased ADA activity was not associated with a specific period during cell-cycle traverse, but, rather, coincided with cell enlargement in preparation for mitosis. In conclusion, either an early event in T-cell mitogenesis is highly susceptible to nucleoside toxicity or a mechanism independent of ADA is acquired during T-cell activation that allows proliferating T-cells to resist toxic concentrations of nucleoside.

Preparation of audiovisual aids for infection control education

This article contains guidelines for selection and design of audiovisual materials pertinent to the teaching of infection control. Clarity, rate of presentation, and color are emphasized because they may correlate directly with effective presentation and learner comprehension. The use of audiovisual programs may cut presentation time in half, thereby achieving long-term cost-effectiveness. Slides project well if appropriate color combination is used, and if copy is limited to six double-spaced, very short lines. Specifications for effective use of color are summarized in the text.

Macrophage-mediated cytostatic activity blocks lymphoblast cell cycle progression independently in both G1 phase and S phase

Recent work has shown that macrophage-mediated cytostatic activity inhibits cell cycle traverse in G1 and/or S phase of the cell cycle without affecting late S, G2, or M phases. The present report is directed at distinguishing between such cytostatic effects on G1 phase or S phase using the accumulation of DNA polymerase alpha as a marker of G1 to S phase transition. Quiescent lymphocytes stimulated with concanavalin A undergo a semisynchronous progression from G0 to G1 to S phase with a dramatic increase in DNA polymerase alpha activity between 20 and 30 hr after stimulation. This increase in enzyme activity was inhibited, as was the accumulation of DNA, when such cells were cocultured with activated murine peritoneal macrophages during this time interval. However, if mitogen-stimulated lymphocytes were enriched for S-phase cells by centrifugal elutriation and cocultured with activated macrophages for 4-6 hr, DNA synthesis was inhibited but the already elevated DNA-polymerase activity was unaffected. Similar results were obtained when a virally transformed lymphoma cell line was substituted as the target cell in this assay. These results show that both G1 and S phase of the cycle are inhibited and suggest that inhibition of progression through the different phases may be accomplished by at least two distinct mechanisms.

Determination of human cone pigment density difference spectra in spatially resolved regions of the fovea

A new method was developed to measure spectrally and spatially resolved cone pigment optical density difference in normal human subjects. Using digitized television images of human retinas scanned before and after bleaching the cone pigments with a bright light, unique high-resolution images of cone pigment density difference were produced. The spectral peak density difference within the fovea was found to be at 560 nm. These measurements demonstrate a decrease in cone pigment optical density difference with increased distance from the subject's central fixation point in the fovea. The cone pigment density difference was asymmetrically distributed in the fovea with higher amounts on the nasal side.

Characterization of the recognition of target cells sensitive or resistant to cytolysis by activated rat peritoneal macrophages

The interaction between tumoricidal rat peritoneal exudate macrophages and normal or neoplastic target cells has been examined both with respect to the sensitivity of the target cells to macrophage-mediated cytolysis and the ability of such targets to compete with one another for the lytic activity of macrophages. The results demonstrate that, in confirmation of earlier work from other laboratories, target cells are either sensitive or largely resistant to lysis, and such sensitivity correlates well with the neoplastic phenotype of the target cell. However, in target cell competition experiments all cultured cells as well as Con A-stimulated splenocytes and freshly isolated thymocytes exhibit the capacity to block cytolysis of sensitive indicator targets. In contrast, freshly prepared non-mitogen-stimulated splenic or lymph node lymphocytes are completely devoid of competitive activity. These results show that macrophages can recognize and interact with both normal and tumorigenic cells and that such target recognition can be distinguished from target cytolysis. Furthermore, the evidence suggests that at least 1 target cell feature that correlates with recognition is cell cycle traverse.