Characterization of serum adhesive proteins that block tumor necrosis factor-mediated cell death

Previously we have shown that TGF-beta1 protects murine L929 fibroblasts from TNF/ActD-mediated cell death by inducing the expression of an extracellular matrix TNF-resistance triggering (TRT) protein. TRT promotes TNF-resistance via activation of tyrosine and serine/threonine kinases in L929 cells. To examine the presence of TRT activity in serum (designated STRT), human sera were diluted, treated with or without PMSF and subjected to sequential ammonium sulfate precipitation (ASP). Aliquots of the ASP protein fractions were coated onto 96-well plates, followed by thorough washing. When L929 cells were seeded and cultured on the wells coated with STRT proteins, these cells resisted killing by TNF, TNF/ActD, doxorubicin and serum deprivation, but not by anti-Fas/ActD, staurosporine and ActD. STRT activity was found at the 15% ASP fraction of untreated sera, but shifted to the 20% ASP fraction of PMSF-treated sera. Two likely STRT proteins of approximately 226 and 265 kDa were found in these fractions, compared to the corresponding nonfunctional ASP fractions. Functionally, STRT was inactivated by trypsin, but not by 5 M salt, various serine and/or cysteine protease inhibitors, and antibodies against fibronectin, vitronectin, C1q, histidine-rich glycoprotein, CD44, chondroitin sulfate and hyaluronic acid. STRT failed to alter the expression of proteins involved in apoptosis such as RIP, ICH-1L, BCL-X, TIAR and IkappaBalpha, and could not induce IkappaBalpha degradation. The induced TNF-resistance could be reversed by treatment of STRT-stimulated cells with testicular hyaluronidase, as well as with tyrosine kinase inhibitors tyrophostin, lavendustin A and AG-490 (a selective inhibitor of JAK2 kinase). However, the STRT function could not be blocked by the MEK kinase inhibitor PD98059 and the NF-kappaB inhibitors curcumin and a synthetic inhibitor peptide for NF-kappaB translocation. Together, our data suggest that tyrosine kinase activation is involved in the STRT-mediated resistance to TNF and TNF/ActD in L929 cells.

Microcirculation of the diabetic foot

Studies over the last decade have revealed impairment of the microcirculation in the diabetic foot. Endothelial dysfunction along with derangements in numerous biochemical pathways has been implicated as causes of microcirculation impairment. Additionally, reduction or absence of the nerve-axon reflex renders the diabetic foot unable to mount a vasodilatory response under conditions of stress, such as injury or infection and makes it functionally ischemic even in the presence of satisfactory blood flow under normal conditions. Furthermore, these changes appear to be directly related to the presence of diabetic neuropathy. These alterations in the diabetic microcirculation may explain the poor wound healing commonly observed in diabetes.

Benfluorex as a therapeutic option for insulin resistance in HIV lipodystrophy syndrome

BACKGROUND

HIV lipodystrophy syndrome, characterized by a significant excess of visceral adiposity and a reduced subcutaneous fat mass in association with insulin resistance and dyslipidemia, still affects the majority of antiretroviral-treated HIV-infected patients. The therapeutic management of this syndrome has not yet been well established. Benfluorex is known to decrease insulin resistance with no side effects on lactate levels in HIV-negative patients.

METHOD

We conducted an open-label study of benfluorex (150 mg, 2-3 times a day) that was prescribed for 60 HIV-infected patients who were diagnosed with glucose metabolism abnormalities by oral glucose tolerance test (OGTT); 47 of these patients had visceral fat accumulation measured by computed tomography (VAT). Median follow-up was 12 months (interquartile range [IQR] = 6-12 months). The great majority of patients (90%) were treated with at least triple therapy (in 70% the therapy included at least one PI), with a nonsignificant change over the study period.

RESULTS

Added to antiretroviral therapy, benfluorex improved OGTT in 47/60 cases, including total normalization in 34/60 without lactate concentration modification. A trend toward a decrease in VAT distribution was observed (p =.06). No significant difference was observed in subcutaneous fat distribution, although an increase in subcutaneous thigh adipose tissue was observed in 17/47 (36.2%) cases and 6 patients (12.7%) presented both subcutaneous fat increase and VAT decrease.

Efficacy and tolerance of HCV treatment in HIV-HCV coinfected patients: the potential interaction of PI treatment

PURPOSE

To evaluate tolerance and efficacy of an open-label interferon-ribavirin treatment and their determinants in 62 HCV-HIV coinfected patients in routine followup.

METHOD

Patients received at least 6 and up to 12 months of combination interferon alpha-2b (peg or not) plus ribavirin. Determinants of therapeutic success were estimated by a multivariate logistic regression.

RESULTS

Five patients stopped the study, 4 were lost to follow-up, and 53 participated in the entire therapeutic protocol. Among these 53, the end-of-treatment results showed complete clearance of HCV-RNA in 17 (32%). A sustained virologic response (SVR) after 6 or 9 months was observed in 9 (17%) patients, 3 relapsed, and data were not available for 5. Genotype 3a (odds ratio [OR] = 14.4; confidence interval [CI] = 1.84-110.3) favored SVR and treatment with protease inhibitor (PI) therapeutic resistance (OR = 14.4; CI = 1.01-200); as well, a higher fibrosis score tended to increase resistance (p =.11). Adverse events were reported by 24/53 patients (45.3%).

CONCLUSION

HCV therapy associating interferon and ribavirin in HCV-HIV coinfected patients is well accepted even if tolerance is moderate. Treatment permitted SVR in at least 17% of the cases. This is likely when patients initiate treatment at the early fibrosis stage and are infected with genotype 3a. The potential interaction with PI therapy should be explored.

Reconstruction of the perineum

Defects of the perineal area commonly occur following ablative procedures for gynecological, urological, and colorectal malignancies. A coordinated approach between the surgical oncologist and the reconstructive surgeon is necessary in order to achieve appropriate results in these patients. Consideration of both form and function is essential and must be planned for. A variety of reconstructive procedures, including skin grafts, local skin flaps, various myocutaneous and fasciocutaneous flaps and, in rare situations, free tissue transfers, are used in the closure of these wounds. An algorithm for the selection of these various procedures is presented so that uncomplicated wound healing can be achieved and functional results can be optimized. Semin. Surg. Oncol. 19:282-293, 2000.

Generational differences in psychosocial adaptation and predictors of psychological distress in a population of recent Vietnamese immigrants

While first-wave Vietnamese immigrants adapted well to life in the United States, subsequent immigrants have had greater adjustment difficulties, including more evidence of psychological distress. This study aimed to analyze psychosocial adaptation differences among three generations of recent Vietnamese immigrants, as well as to examine predictors of mental distress in the sample as a whole. A community sample of 184 recent Vietnamese immigrants, categorized as either elderly, middle-aged, or young adults, was assessed for levels of psychological distress, including depression, anxiety, and PTSD, as well as family conflict, dissatisfaction with life in the U.S., acculturation and biculturalism, social support, coping, and premigratory stressors. Young Vietnamese adults were most acculturated, most bicultural, and reported themselves as healthiest and least depressed. They were most often working, least often on welfare, and had the highest family income. However, they also reported most dissatisfaction with their current lives in the U.S. and most family conflict. Regression analysis explaining approximately one-quarter of the variance in mental distress implicated current dissatisfaction with and lack of adjustment of life in the United States, as well as greater acculturation and increased family conflict. Although young adults scored significantly higher than other generations on most of the risk factors for psychological distress, they appeared to be buffered against poorer mental health outcomes by factors of generation and perceived positive overall well-being. In terms of testing a predictive model of psychological distress, this study found current adjustment factors significantly more important in determining mental health outcomes than premigratory stressors such as war-related traumas.

Isolation of erythropoietin receptor agonist peptides using evolved phage libraries

Cyclic peptides capable of activating the erythropoietin receptor (EPOR) were isolated from phage display libraries by screening with a novel EPOR-IgG fusion protein reagent. A parental clone ERB1 (EPO Receptor Binder 1) was first isolated from a phage display library displaying 38 random amino acids as an N-terminal fusion with the M13 minor capsid protein, pill. An evolved library was then produced from the parental sequence using an oligonucleotide saturation mutagenesis strategy which yielded EPOR binding sequences with 20 times the relative affinity of ERB1. Two synthetic peptides were constructed from these sequences both of which bind the EPO receptor in specific ELISA, and act as full agonists in EPO dependent cell proliferation assays. These peptides are 18 amino acids in length, disulfide-bonded, and have a minimum consensus sequence of CXXGWVGXCXXW, where X represents positions tolerant of several amino acids.

Division of the transverse carpal ligament and flexor tendon excursion: open and endoscopic carpal tunnel release

Ten fresh cadaver upper extremities from 10 different subjects were used in this study of the effect of both open and endoscopic carpal tunnel release on flexor tendon excursion. The amount of excursion necessary to bring each finger from the fully extended to the fully flexed position with the fingertip just touching the palm was measured with the extremity mounted in a device that moved the wrist from extension through flexion. Endoscopic carpal tunnel release, open release, and transverse carpal ligament reconstruction were performed with tendon excursion measurements made in each of four wrist positions after each procedure. Fingertip to palm distance was also measured. The measurements of flexor tendon excursion in neutral wrist position with intact transverse carpal ligament served as the norm for each finger and as the denominator in the ratio of postoperative to preoperative excursion distances. The study confirmed the importance of the transverse carpal ligament as a flexor pulley; transection of the ligament increased the amount of flexor tendon excursion necessary to achieve finger flexion and fingertip-to-palm contact. Tendon excursion/digital flexion improved after transposition flap repair. Neither open nor endoscopic carpal tunnel release conferred any particular benefit to flexor tendon excursion postoperatively. The proximal palmar aponeurosis does not seem to have the same pulley effect as the transverse fibers of the distal palm.

Effect of nerve block on sural amplitude during remote muscle contraction

We previously reported that the median sensory nerve action potentials (SNAPs) increased in amplitude during both near (3) and remote (4) muscle contraction. The objective of the present project was to begin to study the pathway by which this occurred. The sural amplitude was measured after one min. of isometric biceps contraction and compared pre and post lidocaine nerve block in 10 healthy subjects. The baseline was defined as the least amount of current needed to elicit a minimal sural response pre contraction. This level of stimulus remained constant throughout the experiment. Results showed that the sural amplitude peaked 4 min. after muscle contraction. An 8.1 microV increase in sural amplitude from baseline was noted pre injection as 5 min. post contraction, and an increase of 13.4 microV was noted comparing pre to post injection amplitudes at the same time. Statistical analysis using two-way interaction comparing the time courses pre and post injection showed a 92% chance the responses were dissimilar Post hoc least significant difference (LSD) analyses were significant at 4 min. (p = .005) and 6 min. (p = 0.29) post contraction. In conclusion, the increase in sural amplitude after remote muscle contraction was no longer apparent after proximal sural nerve block. This suggests that the nerve itself is required in the final common pathway for the transmission of this induced signal.

Impact of vision impairment on functioning

PURPOSE

The aim of the present study was to determine the impact of vision loss on the activities of adults.

METHODS

Focus groups were conducted that were either disease specific, such as for people with age-related macular degeneration, diabetic retinopathy, glaucoma or those with congenital vision impairment, or according to previous involvement in rehabilitation services. Discussions were recorded and transcribed. Because many people were retired, leisure activities and personal independence were paramount.

RESULTS/CONCLUSIONS

Younger people were concerned with gaining or continuing in employment or with educational opportunities. The age at onset of vision loss and the cause and duration of vision loss influence its impact. There appears to be a greater level of handicap in people with comorbid eye disease and related disease, such as diabetes.

On-site colposcopy services in a family practice residency clinic: impact on physician test-ordering behavior, patient compliance, and practice revenue generation

BACKGROUND

Using colposcopy as a model, we examined the impact of introducing a new diagnostic technology into the ambulatory primary care setting.

METHODS

Records of patients with abnormal findings on Papanicolaou smears were reviewed from three study periods: 1 year before, 1 year after, and 5 years after initiation of on-site colposcopy services. Data analyzed include physician management decisions, site of colposcopic service, and patient compliance. Practice revenue estimates were based upon patterns of physician management and patient compliance found during each study period.

RESULTS

Management of low-grade squamous intraepithelial lesions varied during each study period. By period 3, however, most patients were undergoing colposcopy (P = 0.03). High-grade squamous intraepithelial lesions were uniformly managed with colposcopy during all study periods (P < 0.001). Introduction of on-site colposcopic services resulted in a rapid shift to the on-site location for evaluation of low-grade squamous intraepithelial lesions and a more gradual shift to the on-site location for evaluation of high-grade squamous intraepithelial lesions. Patient compliance was not affected by the introduction of on-site services. On-site colposcopy resulted in a nearly 100 percent transfer of revenue to the practice, but the economic benefit was quite modest.

CONCLUSIONS

Although offering on-site colposcopy services might have had some impact on physician management of low-grade squamous intraepithelial lesions, the lack of benefit regarding patient compliance, the relatively small patient volume for this procedure, and its modest impact on practice revenue cause us to question the value of including colposcopy in everyday practice.

Multidrug-resistant transport proteins in yeast: complete inventory and phylogenetic characterization of yeast open reading frames with the major facilitator superfamily

Screening of the complete genome sequence from the yeast Saccharomyces cerevisiae reveals that 28 open reading frames (ORFs) are homologous to each other and to established bacterial members of the drug-resistant subfamily of the major facilitator superfamily. The phylogenesis of these protein sequences shows that they fall into three major clusters. Cluster I contains 12 ORFs, cluster II contains ten ORFs and cluster III contains six ORFs. Hydropathy analyses indicate that in cluster II and III ORFs, 14 transmembrane spans are predicted whereas only 12 transmembrane spans are predicted in cluster I ORFs. Three ORFs that have known functions as multidrug-resistance pumps in other yeast species such as Schizosaccharomyces pombe (CAR1), Candida albicans (BMRP) or C. maltosa (CYHR), also fall into cluster I. Two S. cerevisiae ORFs of known multidrug-resistance function (ATR1, SGE1) fall into cluster II. Cluster III consists exclusively of ORFs of unknown function but binary sequence comparisons show homology to ORFs from cluster II. Analysis of the multiple alignment for these proteins leads to the identification of characteristic signature sequences for each of the three clusters.

The community health center and family practice residency training

Community health centers (CHCs), sponsored by US Public Health Service (USPHS) Section 330, represent successful models of the application of community-oriented primary care principles. Recently, increased interest has been shown in conducting medical education programs in CHCs. The USPHS has tried to facilitate this interest, particularly through its support of establishing linkages between CHCs and family practice residency programs. In this paper, we describe an integrated CHC-family practice residency continuity training clinic program. We discuss the challenges inherent to conducting family practice residency training in the CHC, including the educational content of clinical experiences, the impact of provider productivity expectations, the academic and operational governance of the program, and the financial considerations pertinent to the integrated function of the program. We conclude that while the clinical experiences available in the CHC differ somewhat from mainstream family practice, successful adaptations can be made, and a CHC offers a rich educational environment. We also conclude that the challenges inherent to integrated CHC-family practice residency programs can be successfully addressed. Of great concern, however, are financial considerations relevant to the operation of such integrated programs. These considerations underscore the urgent need for a reassessment of the funding of ambulatory clinical medical education.

Once-daily aminoglycoside dosing in immunocompetent adults: a meta-analysis

OBJECTIVE

To compare the efficacy, nephrotoxicity, and ototoxicity of once-daily aminoglycoside dosing with those of standard aminoglycoside regimens in immuno-competent adults.

DATA SOURCES

A structured MEDLINE search from 1966 to April 1995 using the keywords aminoglycosides, drug administration schedule, and adult; bibliographic searching of review articles, position papers, and references of the selected articles; contact with primary authors of selected articles to obtain information not in the published reports and lists of potentially relevant articles.

STUDY SELECTION

Randomized, controlled trials that 1) compared an intravenous once-daily aminoglycoside regimen with a standard aminoglycoside regimen in infected immunocompetent adults and 2) examined efficacy, mortality, or toxicity.

DATA EXTRACTION

For each selected study, two independent reviewers assessed methodologic quality and abstracted data. The heterogeneity of individual study risk ratios was assessed and data were pooled using a random-effects model.

RESULTS

Forty-two studies were reviewed for possible inclusion. Thirteen independent studies met the selection criteria, and their results were pooled. The trials had a mean methodologic quality score of 0.69 (range, 0.50 to 0.91). Heterogeneity exists among the individual risk ratios for clinical cure (P = 0.07); significant heterogeneity does not exist for the other outcomes. For the pooled efficacy outcomes, the risk ratio for bacteriologic cure is 1.02 (95% CI, 0.99 to 1.05), and the risk ratio for mortality is 0.91 (CI, 0.63 to 1.31). For the pooled toxicity outcomes, the risk ratio for nephrotoxicity is 0.87 (CI, 0.60 to 1.26), and the risk ratio for ototoxicity is 0.67 (CI, 0.35 to 1.28).

CONCLUSIONS

Standard and once-daily aminoglycoside dosing regimens are equivalent with regard to bacteriologic cure, and once-daily dosing shows a trend toward reduced mortality and toxicity. However, additional studies are needed for more precise estimates of mortality and toxicity risk ratios. The equivalency of the dosing regimens, the ease of administration, reduced nursing time, and reduced variability in the timing of drug administration that are associated with once-daily dosing may mean that the once-daily regimen is clinically advantageous.

Childhood hearing impairment: auditory and linguistic interactions during multidimensional speech processing

Children with mild-severe sensorineural hearing losses often use hearing aids and aural/oral language as their primary mode of communication, yet we know little about how speech is processed by these children. The purpose of this research was to investigate how the multidimensional information underlying accurate speech perception is processed by children with mild-severe hearing impairments. The processing of the auditory and linguistic dimensions of speech was assessed with a speeded selective-attention task (Garner, 1974a). Listeners were required to attend selectively to an auditory dimension (gender of the talker) and ignore a linguistic dimension (word) and vice versa. The hypothesis underlying the task is that performance for the target dimension will be unaffected by what is happening on the nontarget dimension if the dimensions are processed independently. On the other hand, if the dimensions are not processed independently, listeners will not be able to attend selectively and performance for the relevant dimension will be affected by what is happening on the irrelevant dimension (termed "Garner" interference). Both children with normal hearing (N = 90) and children with hearing impairment (N = 40) showed some degree of Garner interference, implying that the dimensions of speech are not processed independently by these children. However, relative to the children with normal hearing, the children with hearing impairment showed normal Garner interference when attending selectively to the word dimension (normally effective at ignoring talker-gender input) and reduced Garner interference when attending selectively to the talker-gender dimension (more effective at ignoring word input). This pattern of results implies that the auditory dimension has a normal strength-of-processing level that makes it normally distracting and that the linguistic dimension has an underdeveloped strength-of-processing level that makes it easier to ignore in children with hearing impairment.

A family of extracytoplasmic proteins that allow transport of large molecules across the outer membranes of gram-negative bacteria

Seventeen fully sequenced and two partially sequenced extracytoplasmic proteins of purple, gram-negative bacteria constitute a homologous family termed the putative membrane fusion protein (MFP) family. Each such protein apparently functions in conjunction with a cytoplasmic membrane transporter of the ATP-binding cassette family, major facilitator superfamily, or heavy metal resistance/nodulation/cell division family to facilitate transport of proteins, peptides, drugs, or carbohydrates across the two membranes of the gram-negative bacterial cell envelope. Evidence suggests that at least some of these transport systems also function in conjunction with a distinct outer membrane protein. We report here that the phylogenies of these proteins correlate with the types of transport systems with which they function as well as with the natures of the substrates transported. Characterization of the MFPs with respect to secondary structure, average hydropathy, and average similarity provides circumstantial evidence as to how they may allow localized fusion of the two gram-negative bacterial cell membranes. The membrane fusion protein of simian virus 5 is shown to exhibit significant sequence similarity to representative bacterial MFPs.

Linguistic influences on the auditory processing of speech by children with normal hearing or hearing impairment

OBJECTIVE

The accurate perception of speech requires the processing of multidimensional information. The aim of this research was to examine linguistic influences on the auditory processing of speech in the presence of childhood hearing impairment.

DESIGN

The processing interactions characterizing the linguistic and auditory dimensions were assessed with a pediatric auditory analog of the Pomerantz task (Pomerantz, Pristach, & Carson, 1989). The task yields measures of Stroop interference, the effect of irrelevant semantic content, and of Garner interference, the effect of irrelevant linguistic variability (Stroop, 1935; Garner, 1974a). Subjects were 100 normal-hearing children and 60 hearing-impaired children. Subjects were required to attend selectively to the auditory (voice-gender) dimension and to ignore the linguistic dimension. The logic of the task is that performance for the voice-gender dimension will be unaffected by what is happening on the irrelevant dimension if the dimensions are processed independently. On the other hand, if the dimensions are not processed independently, subjects will not be able to attend selectively and performance for the relevant dimension will be affected by what is happening on the to-be-ignored dimension.

RESULTS

Both the normal-hearing and hearing-impaired children showed auditory Stroop and Garner interference effects, indicating that the auditory and linguistic dimensions were not processed independently by either group. However, the linguistic dimension exerted significantly less influence on auditory processing in the presence of childhood hearing impairment. Whereas normal-hearing children had remarkable difficulty ignoring irrelevant word input and focusing exclusively on voice-gender, hearing-impaired children were relatively successful at ignoring the linguistic dimension and attending selectively to the auditory dimension of speech. This result implies that the linguistic dimension of auditory speech input may have a different weight or processing value in the presence of childhood hearing impairment. It may be the case that hearing-impaired children encode spoken speech disproportionately in terms of the auditory dimensions, which offer important supplementary aids to speechreading. Further research is being carried out to address these possibilities.

CONCLUSIONS

Both Stroop and Garner interference were significantly reduced in the presence of childhood hearing impairment. This pattern of results suggests that multidimensional speech processing is carried out in a less stimulus-bound manner in the presence of childhood hearing impairment.

Selective alpha-blockade versus angiotensin-converting enzyme inhibition as initial antihypertensive therapy. Effects on circulating lipoproteins

This study evaluated the overall efficacy and safety of two specific vasodilators--the alpha-blocker prazosin and the angiotensin-converting enzyme inhibitor captopril--in the treatment of mild-to-moderate essential hypertension. Because the current approach to antihypertensive treatment should consider possible drug-related changes in circulating lipid fractions, the present study investigated the effects of these two drugs on lipid parameters as well. Used either as single agents or in combination with hydrochlorothiazide, both drugs effectively reduced high blood pressure. Neither drug had adverse effects on the lipid profile in general, although there were significant differences between the effects of prazosin and captopril on total cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B.

Distribution of bombesin-like peptides in the alimentary canal of several vertebrate species

The objective of this study was to quantitate and characterize the variants of bombesin-like immunoreactivity in the alimentary canal of the rat, rabbit, hawk, owl, dog, monkey and human. Bombesin-like immunoreactivity was found throughout the entire gastrointestinal tract of all species studied. In the rat, the highest concentration of bombesin-like immunoreactivity was found in the colon. Gel chromatography showed that bombesin-like immunoreactivity corresponded to gastrin-releasing peptide (GRP-27) and GRP-10. In the dog, the greatest concentration of bombesin-like immunoreactivity was observed in the mucosal layer of the fundus, whereas the concentration of bombesin-like immunoreactivity in the muscle layer of the dog did not vary significantly from region to region. Gel chromatography showed that bombesin-like immunoreactivity in the dog corresponded to GRP-27, bombesin, GRP-10, and a smaller fragment. In the human, the concentration of bombesin-like immunoreactivity did not vary significantly from region to region in the mucosal and muscular layers. Gel chromatography of human fundal mucosa showed that bombesin-like immunoreactivity peaks occur in the regions of GRP-27, bombesin and GRP-10. These findings substantiate the observation that bombesin-like peptides play a variety of roles in the regulation of gut function.