Cationic liposome-mediated uptake of human immunodeficiency virus type 1 Tat protein into cells

The human immunodeficiency virus type 1 (HIV-1) Tat protein strongly transactivates gene expression from the viral long terminal repeat (LTR) and is required for virus efficient replication. Previous studies have shown that cells scrape-loaded in the presence of purified recombinant Tat can absorb the protein in a receptor-independent fashion. Using recombinant Tat in which cysteine residues were blocked by sulfitolysis to prevent disulfide aggregation (S-Tat) we were unable to observe this phenomenon, possibly because of improper protein folding. In this study we report that the block to cellular uptake could be overcome by mixing S-Tat with a cationic liposome, Lipofectin. When mixed with Lipofectin, S-Tat effected a specific, concentration-dependent transactivation of HIV-1 LTR-directed reporter gene activity in Hela Cells. Cellular uptake was confirmed by Western blot analysis with an anti-Tat antibody. The method described utilizes cells plated in a 96-well format, requires only nanogram quantities of S-Tat protein and is much less labor-intensive than assays involving scrape-loading, making it suitable for use as a high-throughput screen for detecting Tat inhibitors. The method may have applications for the analysis of other recombinant proteins that require uptake into intact cells for determination of functionality and presents a general technique for introducing exogenous proteins into cells.

Detection of specific human immunodeficiency virus type 1 Tat-TAR complexes in the presence of mild denaturing conditions

Gene expression from the human immunodeficiency virus 1 (HIV-1) is greatly enhanced by binding of the virally encoded Tat protein to a 59-base RNA stem-loop structure, the Transactivation Responsive Element (TAR), located at the 5'-termini of all viral transcripts. This interaction was investigated in vitro using 32P-labelled TAR and highly purified Tat in which cysteine residues were blocked by sulpitolysis (S-Tat). It is shown that specific complex formation between S-Tat and TAR can occur in the presence of urea, with urea concentrations between 5 and 6 M causing an approximately two-fold increase in the level of binding. Two conditions favoring RNA secondary structure, low temperature (0 degree C) and the presence of divalent cations (Mg2+), diminished the level of specific binding. These observations suggest that the presence of mild denaturants promoted macromolecular refolding or rearrangement in a manner that increased the number of molecules available for binding, and present a general method for studying protein/RNA interactions where analysis has been obstructed by improper protein or RNA conformation.

Distorted visual feedback effects on drawing in Parkinson's disease

We investigated the effects of distorted visual feedback on the drawing performance of a group with Parkinson's disease (PD) and a control group. Twenty older healthy adults and 20 PD patients copied figures onto a digitizer tablet with a pen under normal and distorted visual feedback conditions. PD patients were less able than controls to adjust the size of their drawing to compensate for distortions in visual feedback. The effect was particularly pronounced when patients were required to draw smaller than normal. Nevertheless, with practice. PD patients showed a similar degree of improvement in size as controls, although they did not match the control group's level of performance. Overall, these findings support the notion that PD may have specific difficulty adjusting to a change in gain (or discrepancy) between visual and kinesthetic feedback when they must alter the size of their drawing. These findings point to the putative role of the basal ganglia in adjusting for the intermodal discrepancy between sensory feedback, and re-scaling the size of movements.

Sleep disturbances in Parkinson's disease patients and spouses

OBJECTIVES

The prevalence of self-rated sleep disturbance in patients with Parkinson's disease (PD) and their spouses was compared with healthy controls, and the association of sleep disturbance with demographic, psychological, and disease variables was assessed.

DESIGN

The sleep ratings from three groups, PD patients, their spouses, and healthy controls, were compared using analyses of variance. Stepwise regressions were used to predict sleep disturbance for each group and gender.

SETTING

Participants completed questionnaires as part of a nationwide survey in Germany.

PARTICIPANTS

Participants included 153 PD-spouse pairs and a group of 103 healthy controls.

MEASUREMENTS

Zung Self-Rating Depression Scale and self-ratings of sleep disturbance, stress level, and disease symptoms (for PD patients).

RESULTS

Sleep disturbances were significantly higher in women than in men in all groups. For PD patients, sleep disturbance occurred frequently in 25% of male and 41% of female participants and was best predicted by the patient's depression rating. For spouses, frequent sleep disturbance was reported by 27% of male and 48% of females and was likewise predicted by the spouse's own rating of depression. A second, relatively less common type of sleep disturbance was also reported by spouses. This disturbance was associated with waking during the night to help the patient and was best predicted by patient factors.

CONCLUSION

Improvement of sleep quality of caregivers may be an important component of treatment to reduce distress caused by PD.

Accuracy of the diagnosis of hypertensive nephrosclerosis in African Americans: a report from the African American Study of Kidney Disease (AASK) Trial. AASK Pilot Study Investigators

African Americans have excess hypertension and end-stage renal disease presumed due to hypertension compared to Caucasians. The AASK was designed to examine the impact of antihypertensive therapies and two levels of blood pressure control on the rate of decline of GFR in African Americans with presumed hypertensive renal disease. During the pilot phase of the trial, eligible participants were requested to undergo renal biopsy to assess the underlying lesions in this population. Eighty-eight hypertensive (diastolic BP > 95 mm Hg) non-diabetic African American patients between the ages of 18 to 70 years, with GFR between 25 to 70 ml/min/1.73 m2 and without marked proteinuria were assessed for possible renal biopsy. Forty-three patients did not undergo renal biopsy due to refusal or contraindications. Adequate renal biopsies were obtained in 39 of the remaining 46 patients. Biopsy findings were analyzed and then compared to clinical parameters. The 39 patients studied, 29 men and 10 women, were on average 53.0 +/- 11.0 years old, and had a MAP of 109 +/- 15 mm Hg and GFR 51.7 +/- 13.6 ml/min/1.73 m2 (not significantly different from nonbiopsied patients). Thirty-eight of these 39 biopsies showed arteriosclerosis and/or arteriolosclerosis, severity on average 1.5 +/- 0.9 and 1.5 +/- 0.8, respectively on a 0 to 3+ scale. Interstitial fibrosis was moderate, 1.3 +/- 0.9 (0 to 3+ scale). Segmental glomerulosclerosis was present in five biopsies, and in one patient, biopsy and clinical findings were consistent with idiopathic focal segmental glomerulosclerosis. Additional lesions included mesangiopathic glomerulonephritis in one patient, basement membrane thickening suggestive of diabetic nephropathy in one, and cholesterol emboli in two cases. Arteriolar and arterial sclerosis were tightly linked, and correlated with interstitial fibrosis and the reciprocal of serum creatinine. Global glomerulosclerosis was extensive, involving on average 43 +/- 26% of glomeruli. The extent of this lesion did not correlate with degree of arteriolar or arterial thickening, but did correlate with systolic blood pressure (P = 0.0174), the reciprocal of serum creatinine (P = 0.0009), serum cholesterol (P = 0.0129) and interstitial fibrosis (P < 0.0001). These data underscore that renal biopsies in non-diabetic hypertensive African-Americans with mild to moderate renal insufficiency in the absence of marked proteinuria are overwhelmingly likely to show renal vascular lesions consistent with the clinical diagnosis of hypertensive nephrosclerosis.

Dementia and response to pain in the elderly

To investigate the effect of dementia on response to pain, 51 community-dwelling, generally healthy, cognitively intact individuals > or = 65 years old and 44 community- or nursing home-dwelling persons > or = 65 years old with varying severity of dementia were studied. Cognitive status was assessed by standardized clinical evaluation and psychometric test performance. The following responses were measured before, during and after a standard venipuncture procedure: heart rate, the amplitude of respiratory sinus arrhythmia (RSA), self-reported anxiety and pain, and videotaped facial expressions. Although RSA did not differentiate procedural phases, in both samples, mean heart rate increased in the preparatory phase and decreased in the venipuncture phase. Independent of age, increasing severity of dementia was associated with blunting of physiologic response as measured by diminished heart rate increase in the preparatory phase and heart rate increase with venipuncture. Dementia significantly interfered with the subjects' ability to respond to direct questions about anxiety and pain. Those who were able to respond were relatively accurate self-assessors: higher anxiety was associated with greater magnitude heart rate responses. Facial expression was increased in demented individuals but it could not be classified by specific emotions. We conclude that dementia influences both the experience and reporting of pain in elderly individuals.

Epilepsy

Diagnosis and management of the epilepsies are routinely performed by primary care physicians. In the United States, only 17% of patients with new-onset epilepsy are examined by neurologic specialists, and even fewer patients employ neurologists for their ongoing care. With the changes dictated by the evolving health care system in the United States, the responsibilities for the treatment of patients with epilepsies by primary care physicians will continue to increase. At the same time, there has been an explosion of new information about the diagnosis, evaluation, natural history, and neurobiologic aspects of epilepsy. New medical and surgical treatments are being introduced with a quickening pace. Finally, the concept that certain epilepsies may be progressive and that early identification and aggressive treatment represent one's best chance for establishing control for these patients has gained widespread confirmation from both clinical and animal model studies. The past standard of care is quickly ending. No longer should a patient or a physician accept only partial seizure control. This monograph attempts to lay the basis for improved understanding of epilepsy so that our patients will be seizure free without side effects and will be able to fully participate in our society.

Facial expression in adults with Down's syndrome

The facial expressions of adults with Down's syndrome (DS; n = 15) as they watched happy, sad, and neutral videotapes were compared with those of a healthy age-matched control group (n = 20). Facial movements were analyzed with the Facial Action Coding System (P. E. Ekman & W. V. Friesen, 1978). While watching happy stimuli, the 10 DS adults who were able to appropriately rate their reactions smiled with a cheek raise as frequently as control adults, suggesting that the expression of positive affect in these individuals is normal. Contrary to predictions, however, the DS group exhibited fewer smiles without cheek raises than did control adults and were more likely not to smile. Neither group showed prototypic sad facial expressions in response to sad stimuli. Independent of emotion, DS participants made more facial movements, including more tongue shows, than did control participants. Differences in facial expression in DS adults may confuse others' interpretations of their emotional responses and may be important for understanding the development of abnormal emotional processes.

Structural comparison of a 15 residue peptide from the V3 loop of HIV-1IIIb and an O-glycosylated analogue

As part of a program to study the effect of glycosylation on the three-dimensional structures of HIV-1IIIB V3 peptide constructs, we have examined the solution structures of a 15 residue peptide (RIQRGPGRAFVTIGK, P18IIIB)- originally mapped as an epitope recognized by CD8+ Dd class I MHC-restricted murine cytotoxic T-lymphocytes (CTL), and an analogue (P18IIIB-g), O-glycosylated with an alpha-galactosamine on Thr-12, using NMR, circular dichroism and molecular modeling methods. Our studies show that the peptides sample mainly random conformations in aqueous solution near 25 degrees C and become more ordered by the addition of trifluoroethanol. Upon decreasing the temperature to 5 degrees C, a reverse turn is formed around the immunodominant tip (G5-R8). Glycosylation on T12 'tightens' the turn slightly as suggested by NOE and CD analysis. In addition, the sugar has a defined conformation with respect to the peptide backbone and influences the local peptide conformation. These data suggest that simple glycosylation may influence the conformational equilibrium of a V3 peptide which contains a domain critical for antibody recognition and virus neutralization. We also show that the ability of cytotoxic T-lymphocytes (CTL) to lyse tumor cells presenting P18IIIB was completely abrogated by threonine glycosylation.

Isolation and sequencing of the rho gene from Streptomyces lividans ZX7 and characterization of the RNA-dependent NTPase activity of the overexpressed protein

The gene for transcription termination factor Rho was isolated from Streptomyces lividans ZX7. It encoded a 77-kDa polypeptide (Rho 77) with considerable homology to known Rho factors. An atypical hydrophilic region of 228 residues was found within the N-terminal RNA-binding domain. Only Rho from Micrococcus luteus and Mycobacterium leprae (closely related GC-rich Gram-positive bacteria) had an analogous sequence. Rho 77 was overexpressed in Escherichia coli and purified using an N-terminal hexahistidine-tag. Rho 77 displayed a broad RNA-dependent ATPase activity, with poly(C) RNA being no more than 4-fold more effective than poly(A). This contrasts with the ATPase activity of Rho from E. coli which is stimulated primarily by poly(C) RNA. Rho 77 was a general RNA-dependent NTPase, apparent Km values for NTPs were: GTP 0.13 mM, ATP 0.17 mM, UTP 1.1 mM, and CTP >2 mM. Rho 77 poly(C)-dependent ATPase activity was inhibited by heparin, unlike the E. coli Rho. The antibiotic bicyclomycin inhibited the in vitro RNA-dependent ATPase activity of Rho 77, did not inhibit growth of streptomycetes but delayed the development of aerial mycelia. N-terminal deletion analysis to express a truncated form of Rho (Rho 72, 72 kDa) indicated that the first 42 residues of Rho 77 were not essential for RNA-dependent NTPase activity and were not the targets of inhibition by heparin or bicyclomycin.

Spontaneous and posed facial expression in Parkinson's disease

Spontaneous and posed emotional facial expressions in individuals with Parkinson's disease (PD, n = 12) were compared with those of healthy age-matched controls (n = 12). The intensity and amount of facial expression in PD patients were expected to be reduced for spontaneous but not posed expressions. Emotional stimuli were video clips selected from films, 2-5 min in duration, designed to elicit feelings of happiness, sadness, fear, disgust, or anger. Facial movements were coded using Ekman and Friesen's (1978) Facial Action Coding System (FACS). In addition, participants rated their emotional experience on 9-point Likert scales. The PD group showed significantly less overall facial reactivity than did controls when viewing the films. The predicted Group X Condition (spontaneous vs. posed) interaction effect on smile intensity was found when PD participants with more severe disease were compared with those with milder disease and with controls. In contrast, ratings of emotional experience were similar for both groups. Depression was positively associated with emotion rating but not with measures of facial activity. Spontaneous facial expression appears to be selectively affected in PD, whereas posed expression and emotional experience remain relatively intact.

Prednisone improves renal function and proteinuria in human immunodeficiency virus-associated nephropathy

PURPOSE

To determine if prednisone ameliorates the course of human immunodeficiency virus-associated nephropathy (HIV-AN).

PATIENTS AND METHODS

Twenty consecutive HIV-infected adults with biopsy-proven HIV-AN (n = 17) or clinical characteristics of HIV-AN (n = 3) with serum creatinine concentrations > 177 mumol/L (2 mg/dL) or proteinuria > 2.0 g/d or both were prospectively evaluated and treated with prednisone at a dose of 60 mg/d for 2 to 11 weeks, followed by a tapering course of prednisone over a 2- to 26-week period. Serum creatinine concentration, 24-hour protein excretion, serum albumin, and steroid-related adverse effects were assessed before and after treatment.

RESULTS

Nineteen patients had serum creatinine concentrations > 117 mumol/L (2 mg/dL). Two of them progressed to end stage renal disease (ESRD) in 4 to 5 weeks. In 17 patients serum creatinine levels decreased from 717 +/- 103 mumol/L (8.1 +/- mg/dL) (mean +/- SE) to 262 +/- 31 mumol/L (3.0 +/- 0.4 mg/dL) (P < 0.001). Five patients relapsed after prednisone was discontinued and were retreated. In these 5 the serum creatinine declined from 728 +/- 107 mumol/L (8.2 +/- 1.2 mg/dL) to 344 +/- 47 mumol/L (3.9 +/- 0.5 mg/dL) (P < 0.01) in response to the second course of prednisone. Twelve of 13 tested patients showed a reduction in 24-hour urinary protein excretion with an average decrement from 9.1 +/- 1.8 g/d to 3.2 +/- 0.6 g/d (P < 0.005). Serum albumin increased from 24.4 +/- 3.6 g/L to 29.3 +/- 2.6 g/L (P = NS) in the 11 patients with paired 24-hour urine collections for whom pre- and post-treatment determinations were available. In one non-azotemic patient with nephrotic syndrome, protein excretion declined from 15.2 to 2.2 g/day and the serum albumin increased from 4.0 g/L to 31.0 g/L. The 20 patients have been followed for a median of 44 weeks (range 8 to 107). Eight ultimately required maintenance dialysis. Eleven died from complications of HIV disease 14 to 107 weeks after institution of prednisone; none was receiving prednisone at the time of death. Seven are alive and free from ESRD a median of 25 weeks (range 8 to 81) from the initiation of prednisone therapy. Six patients developed a total of seven serious infections while receiving prednisone, including Mycobacterium avium-complex infection in 2 and CMV retinitis in 3.

CONCLUSION

Prednisone improves serum creatinine and proteinuria in a substantial proportion of adults with HIV-AN. Corticosteroid-related side effects are not prohibitive. A prospective, randomized controlled trial is required to confirm these preliminary results.

Getting angry at peers: associations with linking of the provocateur

We examined how preschoolers coped with anger in interactions with well liked and not well liked peers. The free-play interactions of preschool-aged children (M age = 66.27 months) were observed for 6 months. The frequency, causes, and intensity of children's anger, as well as their anger-related reactions, were compared for incidents provoked by peers who were "really liked" to those provoked by peers who were liked only " a little bit." Although there were no differences in the intensity of anger provocations by well liked and not well liked provocateurs, children's responses to provocations by well liked peers were more controlled than was the case for anger provoked by peers who were not well liked. In general, boys were more responsive to how they felt about the provocateur than were girls. These findings suggest that anger episodes with well liked children were less stressful than those with peers who were not well liked.

Characterization of a late promoter from the Streptomyces temperate phage phi C31

An operon expressed late in the lytic cycle of the Streptomyces temperate phage phi C31 was shown to be transcribed from an inducible promoter, phi lp (phage late promoter), which resembled the previously reported early promoters. mRNAs initiated at phi lp were processed at the 3' end (and possibly also the 5' end) of a tRNA(Thr)-like sequence, resulting in leaderless polycistronic mRNAs.

Hypersensitivity to rapamycin of BJAB B lymphoblastoid cells

Proliferation of the BJAB B-lymphoblastoid cell line was rapidly and almost completely suppressed by picomolar concentrations of the immunosuppressive macrolide rapamycin (50% inhibitory concentration 10-20 pM for cells reactivated from stationary phase). This cell line was considerably more sensitive to rapamycin than any other B-lymphoblastoid cell line tested, the Jurkat T-cell line or the HL60 promyelocytic cell line. BJAB cell proliferation was not affected by the related immunosuppressive macrolides FK506 or L-685,818, which bind to the immunophilin FKBP12 competitively with rapamycin and also inhibit its peptidylprolyl cis-trans isomerase activity. Excess FK506 or L-685,818 added simultaneously competitively antagonized rapamycin's anti-proliferative action. Levels of FKBP12 and uptake of rapamycin from the culture medium were also normal in BJAB cells. The hypersensitivity to rapamycin of BJAB cells thus reflects an unusual dependence on the intracellular signalling system targeted by the rapamycin-FKBP12 complex, and may provide a model system for elucidating the role played by this pathway in lymphocyte activation. The proliferation of BJAB cells reactivated from stationary phase can also be used as the basis for a highly sensitive bioassay for the presence of rapamycin in culture media or other biological fluids.

The effects of angiotensin II receptor blockade with losartan on systemic blood pressure and renal and extrarenal prostaglandin synthesis in women with essential hypertension

The major antihypertensive effect of losartan, a nonpeptide angiotensin II antagonist, is thought to be due to inhibition of the pressor effects of angiotensin II. It is possible, however, that losartan alters the synthesis of vasodilator or vasoconstrictor prostaglandins (PG), thus contributing to its antihypertensive effect. Sixteen postmenopausal women with essential hypertension, with a mean age of 59 years and diastolic blood pressures of 95 to 115 mm Hg, were enrolled in a 12-week, single-blind study to determine the effects of losartan on blood pressure, renal and extrarenal PG production, plasma renin activity (PRA), plasma aldosterone, and routine biochemical parameters. The subjects received placebo during weeks 1 to 4, 50 mg losartan daily during weeks 5 to 8, and placebo during weeks 9 to 12. During the 4-week treatment period, there were no significant, sustained changes in renal or extrarenal synthesis of PGE2, PGI2, or thromboxane A2. Losartan significantly reduced systolic blood pressure from 155 +/- 11 mm Hg (mean +/- SD) to 139 +/- 13 mm Hg (P = .001) and diastolic blood pressure from 100 +/- 2 mm Hg to 87 +/- 5 mm Hg (P < .001) despite the fact that the majority of patients had low PRA. Plasma aldosterone concentration decreased from 9.7 +/- 6.5 ng/dL to 5.1 +/- 3.9 ng/dL (P = .002) and serum uric acid declined from 4.6 +/- 0.8 mg/dL to 4.2 +/- 0.8 mg/dL (P = .018) after 4 weeks of treatment with losartan. We conclude that 1) losartan decreases blood pressure in women with essential hypertension and low plasma renin activity; 2) the antihypertensive effect is not associated with sustained changes in renal or extrarenal PG production; and 3) losartan reduces plasma aldosterone and serum uric acid concentrations in patients with essential hypertension.

A preliminary description of nonschool-based friendship in young high-risk children

This study explored friendships in a sample of 51 high-risk preschool-aged children. Thirty-eight children were placed in foster care (25 placed with their siblings and 13 separated from their siblings). Thirteen children, receiving preventive services, were living at home with their biological parents and siblings. Chi-square, ANOVA, and paired t-tests were used to test for between-group and within-subject differences in the target children's friendships. The results demonstrated that the majority of the high-risk children had a ''best friend." However, the foster children all had friends who could be described as quasi-siblings. The results suggest that foster care placement and the presence of siblings may influence the nature of a child's interactions with nonrelated peers.