Leg symptoms in peripheral arterial disease: associated clinical characteristics and functional impairment

CONTEXT

Persons with lower-extremity peripheral arterial disease (PAD) are often asymptomatic or have leg symptoms other than intermittent claudication (IC).

OBJECTIVE

To identify clinical characteristics and functional limitations associated with a broad range of leg symptoms identified among patients with PAD.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional study of 460 men and women with PAD and 130 without PAD, who were identified consecutively, conducted between October 1998 and January 2000 at 3 Chicago-area medical centers.

MAIN OUTCOME MEASURES

Ankle-brachial index score of less than 0.90; scores from 6-minute walk, accelerometer-measured physical activity over 7 days, repeated chair raises, standing balance (full tandem stand), 4-m walking velocity, San Diego claudication questionnaire, Geriatric Depression Score Short-Form, and the Walking Impairment Questionnaire.

RESULTS

All groups with PAD had poorer functioning than participants without PAD. The following values are for patients without IC vs those with IC. Participants in the group with leg pain on exertion and rest (n = 88) had a higher (poorer) score for neuropathy (5.6 vs 3.5; P<.001), prevalence of diabetes mellitus (48.9% vs 26.7%; P<.001), and spinal stenosis (20.8% vs 7.2%; P =.002). The atypical exertional leg pain/carry on group (exertional leg pain other than IC associated with walking through leg pain [n = 41]) and the atypical exertional leg pain/stop group (exertional leg pain other than IC that causes one to stop walking [n = 90]) had better functioning than the IC group. The group without exertional leg pain/inactive (no exertional leg pain in individual who walks </=6 blocks per week [n = 28]) and the leg pain on exertion and rest group had poorer functioning than those with IC. Adjusting for age, sex, race, and comorbidities and compared with IC, participants with atypical exertional leg pain/carry on achieved a greater distance on the 6-minute walk (404.3 vs 328.5 m; P<.001) and were less likely to stop during the 6-minute walk (6.8% vs 36%; P =.002). The group with pain on exertion and rest had a slower time for completing 5 chair raises (13.5 vs 11.9 seconds; P =.009), completed the tandem stand less frequently (37.5% vs 60.0%; P =.004), and had a slower 4-m walking velocity (0.80 vs 0.90 m/s; P<.001).

CONCLUSIONS

There is a wide range of leg symptoms in persons with PAD beyond that of classic IC. Comorbid disease may contribute to these symptoms in PAD. Functional impairments are found in every PAD symptom group, and the degree of functional limitation varies depending on the type of leg symptom.

"U" curve association of blood pressure and mortality in hemodialysis patients. Medical Directors of Dialysis Clinic, Inc

BACKGROUND

Hypertension may play an important role in the pathogenesis of the excess cardiovascular and cerebrovascular (CV) morbidity observed in hemodialysis patients (HD). However, the optimal blood pressure (BP) range for HD patients has not been defined. We postulated that there is a "U" curve relationship between BP and CV mortality. To explore this hypothesis we studied 5,433 HD patients in Dialysis Clinic Inc., a large not-for-profit chain, over a five year period.

METHODS

Cox regression, with fixed and time-varying covariates, was used to assess the effect of systolic blood pressure (SBP) and diastolic blood pressure (DBP), pre- and post-dialysis, on CV mortality, while adjusting for age, gender, ethnicity, primary cause of end-stage renal disease, Kt/V, serum albumin, and antihypertensive medications.

RESULTS

The overall impact of BP on CV mortality was modest. Pre-dialysis, neither systolic nor diastolic hypertension were associated with an increase in CV mortality. Post-dialysis, SBP > or = 180 mm Hg (RR = 1.96, P < 0.015) and DBP > or = 90 mm Hg (RR = 1.73, P < 0.05) were associated with increased CV mortality. Low SBP (SBP < 110 mm Hg) was associated with increased CV mortality, pre- and post-dialysis.

CONCLUSIONS

The results suggest the presence of a "U" curve relationship between SBP post-dialysis and CV mortality in HD patients.

Gene expression profiles predict complete pathologic response to neoadjuvant paclitaxel and fluorouracil, doxorubicin, and cyclophosphamide chemotherapy in breast cancer

PURPOSE

The goal of this study was to examine the feasibility of developing a multigene predictor of pathologic complete response (pCR) to sequential weekly paclitaxel and fluorouracil + doxorubicin + cyclophosphamide (T/FAC) neoadjuvant chemotherapy regimen for breast cancer.

PATIENTS AND METHODS

All patients underwent one-time pretreatment fine-needle aspiration to obtain RNA from the cancer for transcriptional profiling using cDNA arrays containing 30721 human sequence clones. Analysis was performed after profiling, and 42 patients' clinical results were available, 24 of which were used for predictive marker discovery; 18 patients' results were used as an independent validation set.

RESULTS

Thirty-one percent of patients had pCR (six discovery and seven validation), defined as disappearance of all invasive cancer in the breast after completion of chemotherapy. We could identify no single marker that was sufficiently associated with pCR to be used as an individual predictor. A multigene model with 74 markers (P <or=.09) was built using data from the discovery samples and tested on the validation samples. Overall, a 78% (14 of 18) predictive accuracy was observed, with a 100% (three of three) positive predictive value for pCR, a 73% (11 of 15) negative predictive value, a sensitivity of 43% (three of seven), and a specificity of 100% (11 of 11). The expected response rate to T/FAC neoadjuvant therapy in unselected patients is 28%.

CONCLUSION

Our results suggest that transcriptional profiling has the potential to identify a gene expression pattern in breast cancer that may lead to clinically useful predictors of pCR to T/FAC neoadjuvant therapy.

Reproduction of lesions of postweaning multisystemic wasting syndrome in gnotobiotic piglets

Neonatal gnotobiotic piglets were inoculated with tissue homogenates and low- and high-passage cell culture material to determine if the lesions of the newly described porcine postweaning multisystemic wasting syndrome (PMWS) could be reproduced. For this, 17 3-day-old gnotobiotic piglets were inoculated intranasally with pelleted chloroform-treated, filtered extracts from cell cultures, filter-sterilized homogenates of lymphoid tissue from PMWS-affected piglets, or control materials. Piglets were maintained in germ-free isolators for up to 5 weeks after infection prior to euthanasia and collection of samples for analysis. All piglets inoculated with the viral inocula developed lesions typical of PMWS, including generalized lymphadenopathy, hepatitis, nephritis, interstitial pneumonia, myocarditis, and gastritis. Porcine circovirus (PCV), as well as porcine parvovirus (PPV), was detected in tissues by virus reisolation, polymerase chain reaction analysis, or immunohistochemistry. All infected piglets developed moderate to high titers of antibody to PCV and moderate titers to PPV. No lesions, virus, or virus-specific antibodies were detected in sham-inoculated or uninoculated control piglets. These studies demonstrate that the lesions of PMWS can be experimentally reproduced in gnotobiotic piglets using filterable viral agents derived from pigs with PMWS and provide an experimental basis for further investigation into the pathogenesis and control of this emerging infectious disease in swine.

Antidepressant effects of nicotine in an animal model of depression

Epidemiological studies indicate a high incidence of cigarette smoking among depressed individuals. Moreover, individuals with a history of depression have a much harder time giving up smoking. It has been postulated that smoking may reflect an attempt at self-medication with nicotine by these individuals. Although some animal and human studies suggest that nicotine may act as an antidepressant, further verification of this hypothesis and involvement of nicotinic cholinergic system in depressive symptoms is required. Flinders Sensitive Line (FSL) rats have been proposed as an animal model of depression. These rats, selectively bred for their hyperresponsiveness to cholinergic stimulation, show an exaggerated immobility in the forced swim test compared to their control Flinders Resistant Line (FRL) rats. Acute or chronic (14 days) administration of nicotine (0.4 mg/kg s.c.) significantly improved the performance of the FSL but not the FRL rats in the swim test. The effects of nicotine on swim test were dissociable from its effects on locomotor activity. Moreover, the FSL rats had significantly higher [3H]cytisine binding (selective for the alpha4beta2 nicotinic receptor subtype) but not [125I]alpha-bungarotoxin binding (selective for the alpha7 subtype) in the frontal cortex, striatum, midbrain and colliculi compared to FRL rats. These data strongly implicate the involvement of central nicotinic receptors in the depressive characteristics of the FSL rats, and suggest that nicotinic agonists may have therapeutic benefits in depressive disorders.

Increased rate of suicide among patients with Huntington's disease

The proportion of deaths attributed to suicide was examined among 506 deceased individuals with diagnosed or suspected Huntington's Disease from New England USA. Comparison of this proportion with that of the general population indicated that the odds of a death being due to suicide in the Huntington's disease group is 8.2 times that of the Massachusetts population for persons aged 50 to 69 yr, but no difference appears in the 10 to 49 yr age group. Among the 157 Huntington's disease patients for whom cause of death was known, the corresponding odds estimates are 23.0 for the 50 to 69 yr age group and 2.7 for the 10 to 49 yr age group. More than half of the suicides occurred in individuals who showed early signs of the illness but who had not been diagnosed, suggesting that suicide may occur more frequently in the early stages of the illness.

Mammalian artificial chromosome formation from circular alphoid input DNA does not require telomere repeats

Mammalian artificial chromosomes (MACs) form in HT1080 cells after transfecting linear yeast artificial chromosome constructs minimally containing competent alphoid arrays, a selectable marker and terminal human telomere repeats. Restrictions on the structure of input DNA in MAC formation were investigated by transfecting circular or linear alphoid constructs with or without human telomere arrays and by varying the position and orientation of the telomere arrays on input linear constructs. Circular input DNA efficiently produced MACs. Absence of telomere arrays from circular input molecules did not significantly alter MAC formation rates. Linear constructs capped with telomere arrays generated MACs effectively, but a severe reduction in MAC formation was observed from linear constructs lacking telomere arrays. Human telomere arrays positioned 1-5 kb from linear construct ends and in either orientation were able to promote MAC formation with similar efficiencies. Both circular and linear input constructs generated artificial chromosomes that efficiently segregated in the absence of selection. Telomeres were not detected on the MACs, regardless of the inclusion of telomere arrays on input DNA, suggesting that circular chromosomes were formed. We found no evidence for acquisition of host cell DNA, which is consistent with de novo chromosome assembly.

Glacial-to-Holocene redistribution of carbonate ion in the deep sea

We have reconstructed the glacial-age distribution of carbonate ion concentration in the deep waters of the equatorial ocean on the basis of differences in weight between glacial and Holocene foraminifera shells picked from a series of cores spanning a range of water depth on the western Atlantic's Ceara Rise and the western Pacific's Ontong Java Plateau. The results suggest that unlike today's ocean, sizable vertical gradients in the carbonate ion concentration existed in the glacial-age deep ocean. In the equatorial Pacific, the concentration increased with depth, and in the Atlantic, it decreased with depth. In addition, the contrast between the carbonate ion concentration in deep waters produced in the northern Atlantic and deep water in the Pacific appears to have been larger than in today's ocean.

The Orientation and Molecular Movement of a K+ Channel Voltage-Sensing Domain

Voltage-gated channels operate through the action of a voltage-sensing domain (membrane segments S1-S4) that controls the conformation of gates located in the pore domain (membrane segments S5-S6). Recent structural studies on the bacterial K(v)AP potassium channel have led to a new model of voltage sensing in which S4 lies in the lipid at the channel periphery and moves through the membrane as a unit with a portion of S3. Here we describe accessibility probing and disulfide scanning experiments aimed at determining how well the K(v)AP model describes the Drosophila Shaker potassium channel. We find that the S1-S3 helices have one end that is externally exposed, S3 does not undergo a transmembrane motion, and S4 lies in close apposition to the pore domain in the resting and activated state.

Porcine circovirus-2 and concurrent infections in the field

Porcine circovirus-2 (PCV-2) is the necessary cause of post-weaning multisystemic wasting syndrome (PMWS) in swine; however, a variety of co-factors, including other infectious agents, are thought to be necessary in the full expression of disease. Porcine parvovirus (PPV) was found in the inoculum used in the first experiments to reproduce PMWS in gnotobiotic swine. Retrospective and prospective studies in the field and laboratory have demonstrated PCV-2 can act synergistically with PPV to enhance the severity of PMWS. PCV-2 has been shown to play a role in the porcine infectious disease complex (PRDC). Other co-infecting agents with PCV-2 in the lung include, porcine reproductive and respiratory syndrome virus (PRRSV), swine influenza virus (SIV) and Mycoplasma hyopneumoniae. Exposure of pregnant sows to PPV, PRRSV, or encephalomyocarditis virus may interact with PCV-2 infected foetuses. The severity of hepatic lesions in PCV-2 infected pigs may be enhanced by co-infection with agents such as swine hepatitis E virus and Aujezsky's disease virus. Additional studies are required to determine the mechanistic basis for the interaction of PCV-2 with other agents in the pathogenesis of the various clinical syndromes that have been associated with PCV-2 infection.

Neuroligin1: a cell adhesion molecule that recruits PSD-95 and NMDA receptors by distinct mechanisms during synaptogenesis

BACKGROUND

The cell adhesion molecule pair neuroligin1 (Nlg1) and beta-neurexin (beta-NRX) is a powerful inducer of postsynaptic differentiation of glutamatergic synapses in vitro. Because Nlg1 induces accumulation of two essential components of the postsynaptic density (PSD) - PSD-95 and NMDA receptors (NMDARs) - and can physically bind PSD-95 and NMDARs at mature synapses, it has been proposed that Nlg1 recruits NMDARs to synapses through its interaction with PSD-95. However, PSD-95 and NMDARs are recruited to nascent synapses independently and it is not known if Nlg1 accumulates at synapses before these PSD proteins. Here, we investigate how a single type of cell adhesion molecule can recruit multiple types of synaptic proteins to new synapses with distinct mechanisms and time courses.

RESULTS

Nlg1 was present in young cortical neurons in two distinct pools before synaptogenesis, diffuse and clustered. Time-lapse imaging revealed that the diffuse Nlg1 aggregated at, and the clustered Nlg1 moved to, sites of axodendritic contact with a rapid time course. Using a patching assay that artificially induced clusters of Nlg, the time course and mechanisms of recruitment of PSD-95 and NMDARs to those Nlg clusters were characterized. Patching Nlg induced clustering of PSD-95 via a slow palmitoylation-dependent step. In contrast, NMDARs directly associated with clusters of Nlg1 during trafficking. Nlg1 and NMDARs were highly colocalized in dendrites before synaptogenesis and they became enriched with a similar time course at synapses with age. Patching of Nlg1 dramatically decreased the mobility of NMDAR transport packets. Finally, Nlg1 was biochemically associated with NMDAR transport packets, presumably through binding of NMDARs to MAGUK proteins that, in turn, bind Nlg1. This interaction was essential for colocalization and co-transport of Nlg1 with NMDARs.

CONCLUSION

Our results suggest that axodendritic contact leads to rapid accumulation of Nlg1, recruitment of NMDARs co-transported with Nlg1 soon thereafter, followed by a slower, independent recruitment of PSD-95 to those nascent synapses.

Health-related quality of life in older people with osteoporotic vertebral fractures: a systematic review and meta-analysis

Health-related quality of life in osteoporotic patients with vertebral fracture is of increasing interest, but relevant studies have yielded debatable results. This systematic review and meta-analysis of 16 observational studies demonstrate a clear association between physical health status and presence of vertebral fracture after accounting for age. This meta-analysis was conducted to identify if there are any differences between physical and/or mental health-related quality of life (HRQoL) in older people with osteoporosis based on conventional T-score definitions and the presence or absence of vertebral fracture. A comprehensive search was undertaken using the databases of PubMed, Embase, Medline, Web of Science, and the "grey" literature from 1950 to the end of April 2015. Search terms for vertebral fracture (VF) included VF, osteoporotic fracture, fragility fracture, and spinal fracture. Quality of life was searched using the following terms: quality of life, health-related quality of life, HRQoL, and QoL. Strict inclusion and exclusion criteria were used. The standardized mean difference (SMD) was calculated for each HRQoL domain by the difference in means between case and control groups divided by the pooled SD of participants. Sixteen eligible studies were identified involving 3131 men and women. There was evidence of publication bias and heterogeneity. The meta-analysis showed worse physical (SMD = 0.53, 95 % confidence interval (CI) 0.38 to 0.68; P < 0.001) and mental (SMD = 0.19, 95 % CI 0.05 to 0.33; P = 0.009) HRQoL in osteoporotic older people with vertebral fracture compared to those without fracture. Similar differences were observed for physical HRQoL in further analyses accounting for possible confounding effects of age. Sub-analysis to assess associations between number/severity of fractures and time since fracture was not possible due to small numbers of studies that accounted for age. Osteoporotic older people with vertebral fracture have worse physical HRQoL than osteoporotic older people without vertebral fracture, even after accounting for age differences.

Transcriptional up-regulation of the cyclin D2 gene and acquisition of new cyclin-dependent kinase partners in human T-cell leukemia virus type 1-infected cells

Human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent for adult T-cell leukemia/lymphoma (ATL) and HTLV-1-associated myelopathy/tropical spastic paraparesis. Tax(1) is a 40-kDa phosphoprotein, predominantly localized in the nucleus of the host cell, which functions to transactivate both viral and cellular promoters. It seems likely that HTLV-1, through expression of the viral regulatory protein Tax(1), provides some initial alteration in cell metabolism predisposing the development of ATL. Here, we demonstrate that HTLV-1 infection in T-cell lines and patient samples causes overexpression of an early G(1) cyclin, cyclin D2. The transcriptional up-regulation of the cyclin D2 gene is due to activation of Tax on the cyclin D2 gene. More important, we find that overexpression of cyclin D2 is accompanied by acquisition of new partners such as cyclin-dependent kinase 2 (cdk2), cdk4, and cdk6 in infected cells. This is in contrast to uninfected T cells, where cyclin D2 associates only with cdk6. Functional effects of these cyclin-cdk complexes in infected cells are shown by hyperphosphorylation of Rb and histone H1, indicators of active progression into S phase as well as changes in cellular chromatin and transcription machinery. These studies link HTLV-1 infection with changes of cellular cyclin gene expression, hence providing clues to development of T-cell leukemia.

High morbidity rate after converted laparoscopic colorectal surgery

Sixteen of 65 laparoscopically assisted colorectal operations were converted to an open procedure, usually because of dissection difficulties. Conversion was decided early in the procedure in four cases without perioperative morbidity and later in 12 cases, after a mean of 56 min. The results in patients undergoing converted operation were compared with those in 252 having a planned open colorectal procedure during the same period. The groups were comparable with regard to age, health status, factors influencing intestinal healing and grade of surgeon. A higher postoperative morbidity rate (50 versus 21 per cent) and more anastomotic leakages (25 versus 8 per cent) were apparent in the converted group. Operating time, postoperative ileus and hospital stay were longer in those requiring a converted operation. These poor results suggest that careful preoperative patient selection for laparoscopic procedures and a rapid decision to convert in case of difficulty are important.

A comparison of an effect of different anti-inflammatory drugs on human platelets

Different doses of aspirin, indomethacin, paracetamol, benorylate, and sodium salicylate were taken by four volunteers. The minimal dose that altered a platelet function test and the persistence of this alteration at different dose levels were studied. Minute doses of indomethacin (0.035 mg/kg) were effective but the effect of even a large single dose did not persist. A tenth of the therapeutic dose of aspirin (1 mg/kg) was effective, and higher doses altered the platelets' function for several days. Benorylate in a high therapeutic dose gave aspirin-like results. Paracetamol and sodium salicylate were relatively inactive. The persistence of the aspirin effect may be related to the acetyl group. These findings are surveyed in relation to a general theory of the action of anti-inflammatory drugs.

Microtubule Associated Protein (MAP)-Tau: a novel mediator of paclitaxel sensitivity in vitro and in vivo

Microtubule binding protein Tau was recently identified through gene expression analysis of human breast cancer tissues as a novel marker of response to paclitaxel. This article reviews these recent findings and provides additional information to support the role of Tau as an emerging marker and mediator of paclitaxel sensitivity. Low expression of Tau is associated with increased sensitivity to paclitaxel in human breast cancer as well as in a broad range of cell lines. Down regulation of Tau in cell lines by siRNA increases their sensitivity to paclitaxel but not to anthracycline chemotherapy. We propose that this is due to increased paclitaxel binding to microtubules when microtubules are assembled in the presence of low concentrations (or absence) of Tau compared to microtubules that are formed in the presence of physiological (or higher) levels of Tau.

Facial recognition memory deficits in normal aging and senile dementia

Recognition memory for faces was studied in 167 subjects comprised of young normals, elderly normals and elderly senile dementia patients with mild to moderate cognitive impairment. A continuous recognition paradigm was used which required an "old-new" decision to be made for each facial stimulus. The design of the stimulus sequence produced delay intervals of .5, 1, 2, and 4 min between the first and second presentations of each face, and a long delay of 40 min was also evaluated. A signal detection analysis revealed large recognition memory deficits at all delay intervals for the two elderly groups as compared to the young normals, but no differences between the normal and impaired elderly groups. In addition, there were no group differences in response criterion. The results suggest a deficit in nonverbal encoding/storage due to normal aging but no further deficit due to mild to moderate senile dementia. The data also fail to confirm an age-related increase in "cautiousness" in recognition memory tasks.

Electrical activity during the 2006 Mount St. Augustine volcanic eruptions

By using a combination of radio frequency time-of-arrival and interferometer measurements, we observed a sequence of lightning and electrical activity during one of Mount St. Augustine's eruptions. The observations indicate that the electrical activity had two modes or phases. First, there was an explosive phase in which the ejecta from the explosion appeared to be highly charged upon exiting the volcano, resulting in numerous apparently disorganized discharges and some simple lightning. The net charge exiting the volcano appears to have been positive. The second phase, which followed the most energetic explosion, produced conventional-type discharges that occurred within plume. Although the plume cloud was undoubtedly charged as a result of the explosion itself, the fact that the lightning onset was delayed and continued after and well downwind of the eruption indicates that in situ charging of some kind was occurring, presumably similar in some respects to that which occurs in normal thunderstorms.

Mast cells/basophils in the peripheral blood of allergic individuals who are HIV-1 susceptible due to their surface expression of CD4 and the chemokine receptors CCR3, CCR5, and CXCR4

A population of metachromatic cells with mast cell (MC) and basophil features was identified recently in the peripheral blood of patients with several allergic disorders. This study now shows that these metachromatic cells express on their surface the high-affinity IgE receptor (FcepsilonRI), CD4, and the chemokine receptors CCR3, CCR5, and CXCR4, but not the T-cell surface protein CD3 and the monocyte/macrophage surface protein CD68. This population of MCs/basophils can be maintained ex vivo for at least 2 weeks, and a comparable population of cells can be generated in vitro from nongranulated hematopoietic CD3(-)/CD4(+)/CD117(-) progenitors. Both populations of MCs/basophils are susceptible to an M-tropic strain of human immunodeficiency virus 1 (HIV-1). Finally, many patients with acquired immunodeficiency syndrome have HIV-1-infected MCs/basophils in their peripheral blood. Although it is well known that HIV-1 can infect CD4(+) T cells and monocytes, this finding is the first example of a human MC or basophil shown to be susceptible to the retrovirus. (Blood. 2001;97:3484-3490)

Health-related quality-of-life assessment in CLEOPATRA, a phase III study combining pertuzumab with trastuzumab and docetaxel in metastatic breast cancer

BACKGROUND

The phase III CLEOPATRA study demonstrated that combining pertuzumab with trastuzumab plus docetaxel significantly improves progression-free and overall survival in previously untreated HER2-positive metastatic breast cancer. Here, we report health-related quality-of-life (HRQoL) results from CLEOPATRA.

PATIENTS AND METHODS

Participants were randomly assigned to pertuzumab or placebo, each given with trastuzumab plus docetaxel every 3 weeks. Pertuzumab and trastuzumab were administered until progression and six or more docetaxel cycles were recommended. Time from randomization to a ≥ 5-point decrease in Trial Outcome Index-Physical/Functional/Breast (TOI-PFB) of the Functional Assessment of Cancer Therapy-Breast (FACT-B) questionnaire was analyzed as a prespecified secondary end point. A post hoc exploratory analysis investigated time to ≥ 2-point deterioration in Breast Cancer Subscale (BCS) score.

RESULTS

Time to ≥ 5-point decline in TOI-PFB did not differ significantly between the pertuzumab and placebo arms [hazard ratio (HR), 0.97; P = 0.7161]. The median times to TOI-PFB deterioration were 18.4 and 18.3 weeks, respectively (approximately six cycles). The mean TOI-PFB declined slightly until week 18 and recovered thereafter. Pertuzumab increased time until BCS deterioration versus placebo (median 26.7 versus 18.3 weeks; HR, 0.77; P = 0.0061).

CONCLUSIONS

Combining pertuzumab with trastuzumab and docetaxel had no adverse impact on HRQoL and may prolong time to worsening of breast cancer-specific symptoms.

Loss of G(1)/S checkpoint in human immunodeficiency virus type 1-infected cells is associated with a lack of cyclin-dependent kinase inhibitor p21/Waf1

Productive high-titer infection by human immunodeficiency virus type 1 (HIV-1) requires the activation of target cells. Infection of quiescent peripheral CD4 lymphocytes by HIV-1 results in incomplete, labile reverse transcripts and lack of viral progeny formation. An interplay between Tat and p53 has previously been reported, where Tat inhibited the transcription of the p53 gene, which may aid in the development of AIDS-related malignancies, and p53 expression inhibited HIV-1 long terminal repeat transcription. Here, by using a well-defined and -characterized stress signal, gamma irradiation, we find that upon gamma irradiation, HIV-1-infected cells lose their G(1)/S checkpoints, enter the S phase inappropriately, and eventually apoptose. The loss of the G(1)/S checkpoint is associated with a loss of p21/Waf1 protein and increased activity of a major G(1)/S kinase, namely, cyclin E/cdk2. The p21/Waf1 protein, a known cyclin-dependent kinase inhibitor, interacts with the cdk2/cyclin E complex and inhibits progression of cells into S phase. We find that loss of the G(1)/S checkpoint in HIV-1-infected cells may in part be due to Tat's ability to bind p53 (a known activator of the p21/Waf1 promoter) and sequester its transactivation activity, as seen in both in vivo and in vitro transcription assays. The loss of p21/Waf1 in HIV-1-infected cells was specific to p21/Waf1 and did not occur with other KIP family members, such as p27 (KIP1) and p57 (KIP2). Finally, the advantage of a loss of the G(1)/S checkpoint for HIV-1 per se may be that it pushes the host cell into the S phase, which may then allow subsequent virus-associated processes, such as RNA splicing, transport, translation, and packaging of virion-specific genes, to occur.

Structural consequences of Kcna1 gene deletion and transfer in the mouse hippocampus

PURPOSE

Mice lacking the Kv1.1 potassium channel alpha subunit encoded by the Kcna1 gene develop recurrent behavioral seizures early in life. We examined the neuropathological consequences of seizure activity in the Kv1.1(-/-) (knock-out) mouse, and explored the effects of injecting a viral vector carrying the deleted Kcna1 gene into hippocampal neurons.

METHODS

Morphological techniques were used to assess neuropathological patterns in hippocampus of Kv1.1(-/-) animals. Immunohistochemical and biochemical techniques were used to monitor ion channel expression in Kv1.1(-/-) brain. Both wild-type and knockout mice were injected (bilaterally into hippocampus) with an HSV1 amplicon vector that contained the rat Kcna1 subunit gene and/or the E. coli lacZ reporter gene. Vector-injected mice were examined to determine the extent of neuronal infection.

RESULTS

Video/EEG monitoring confirmed interictal abnormalities and seizure occurrence in Kv1.1(-/-) mice. Neuropathological assessment suggested that hippocampal damage (silver stain) and reorganization (Timm stain) occurred only after animals had exhibited severe prolonged seizures (status epilepticus). Ablation of Kcna1 did not result in compensatory changes in expression levels of other related ion channel subunits. Vector injection resulted in infection primarily of granule cells in hippocampus, but the number of infected neurons was quite variable across subjects. Kcna1 immunocytochemistry showed "ectopic" Kv1.1 alpha channel subunit expression.

CONCLUSIONS

Kcna1 deletion in mice results in a seizure disorder that resembles--electrographically and neuropathologically--the patterns seen in rodent models of temporal lobe epilepsy. HSV1 vector-mediated gene transfer into hippocampus yielded variable neuronal infection.

A comparison of energy expenditure by a high level trans-femoral amputee using the Intelligent Prosthesis and conventionally damped prosthetic limbs

Comparisons were made between the Intelligent Prosthesis (IP), Mauch and pneumatic swing phase control damping systems on the same prosthesis worn by a high level trans-femoral amputee. Speeds self selected by corridor walking (4.4-5.5 kmh-1) proved not to be sustainable for treadmill walking. Comfortable speeds were attained when the subject walked on a treadmill at 2.0, 2.6 and 3.2 kmh-1 in two tests for each prosthesis type. Oxygen uptake (VO2), cadence and heart rate were measured over 5 minute walks interspersed with rest periods. Spearman's correlation was used to test for differences between prosthesis types at each speed. At the two slower speeds no significant difference was found, but at the higher speed of 3.2 kmh-1, the IP was associated with a significantly lower VO2 (p < 0.05). A two way analysis of variance with replication (ANOVA) demonstrated a significant difference between VO2 for different limb types (p = 0.015). A square law function was fitted to the mean VO2 for each prosthesis type by the method of least squares regression. ANOVA demonstrated a significant difference between velocity coefficients for the different prosthesis types (p < 0.05). Cadence was almost constant during the period of each walk, varying by 1 step min-1 at most. However the test-retest differences in cadence were considerable. It is concluded that there was little difference in energy expenditure between prosthesis types at slower speeds, but at higher speeds (==> 3.2km h-1) the IP gave a lower oxygen uptake by about 10%.

Acquisition and retention of categorized material in normal aging and senile dementia

The "shopping list task" is a new verbal learning task with a high degree of face validity for elderly subjects. Learning and delayed recall performance were examined for three groups of subjects: young normals (n = 63, median age = 21), elderly normals (n = 44, median age = 69) and mild to moderately impaired senile dementia patients (n = 60, median age = 70). The young normal subjects performed best of the three groups in both initial learning and delayed recall measures. The elderly normals showed significant decrements in learning and recalling the list items (p less than .01). The impaired elderly showed much greater performance decrements in both learning and recall. None of the subjects showed a deficit in delayed recognition. These results suggest that both storage and retrieval difficulties occur in normal aging and dementia. The recognition test results suggest that recall deficits evidenced by both elderly groups are in large part due to faulty retrieval mechanisms. Since the shopping list task discriminated well among the three groups, it has potential for memory assessment in clinical settings.