Profiles of brain magnetic activity during a memory task in patients with Alzheimer's disease and in non-demented elderly subjects, with or without depression

The presence of depression is common among the elderly and it often complicates the early diagnosis of Alzheimer's disease (AD). In this study, we searched for brain activity measures that characterise AD. We compared brain magnetic activity profiles during a memory task, obtained from patients with AD, elderly patients with late onset depression, and age matched volunteers without history of neurological or psychiatric disease. AD patients showed significantly reduced activity in left temporal lobe regions during late portions of the event related magnetic response (400 ms or later after stimulus onset), compared with both groups of patients who did not present with serious cognitive decline. This finding highlights the potential usefulness of MEG protocols supporting the differential diagnosis of AD and major depression related cognitive decline in the elderly.

Patient and direct-care staff body mass index in a state mental hospital: implications for management

OBJECTIVE

Obesity is a major problem among chronically psychotic patients.

METHOD

We assessed body mass index (BMI) of chronically psychotic patients on admission to a state mental hospital and in follow-up. We also compared patient BMI to staff BMI.

RESULTS

The initial patient BMI (26.4 +/- 5.8 kg/m2) was in the overweight range. The patient BMI (29.1 +/- 5.8 kg/m2) increased (P < 0.0001) on follow-up and almost reached the level of obesity. Staff BMI (35.1 +/- 8.6 kg/m2) was in the obese range with 64.9% meeting criteria of obesity and 29.9% meeting criteria of morbid obesity. African-American women made up 84.5% of clinical-care staff and constitute the race-sex mix most vulnerable to obesity in the US. Morbid obesity (BMI > or = 40 kg/m2) was five times more common among these African-American female clinical-care staff than among African-American women in the general US population.

CONCLUSION

Our findings may have treatment implications for chronically psychotic patients at risk for obesity.

Chirped-pulse oscillators: a route to high-power femtosecond pulses without external amplification

We demonstrate a Kerr-lens mode-locked Ti:sapphire oscillator that generates 130-nJ, 26-fs and 220-nJ, 30-fs pulses at a repetition rate of 11 MHz. The generation of stable broadband, high-energy pulses from an extended-cavity oscillator is achieved by the use of chirped multilayer mirrors to produce a small net positive dispersion over a broad spectral range. The resultant chirped picosecond pulses are compressed by a dispersive delay line that is external to the laser cavity. The demonstrated peak powers, in excess of 5 MW, are to our knowledge the highest ever achieved from a cw-pumped laser and are expected to be scalable to tens of megawatts by an increase in the pump power and (or) a decrease in the repetition rate. The demonstrated source permits micromachining of any materials under relaxed focusing conditions.

Cortical organization for receptive language functions in Chinese, English, and Spanish: a cross-linguistic MEG study

Chinese differs from Indo-European languages in both its written and spoken forms. Being a tonal language, tones convey lexically meaningful information. The current study examines patterns of neurophysiological activity in temporal and temporoparietal brain areas as speakers of two Indo-European languages (Spanish and English) and speakers of Mandarin-Chinese were engaged in a spoken-word recognition task that is used clinically for the presurgical determination of hemispheric dominace for receptive language functions. Brain magnetic activation profiles were obtained from 92 healthy adult volunteers: 30 monolingual native speakers of Mandarin-Chinese, 20 Spanish-speaking, and 42 native speakers of American English. Activation scans were acquired in two different whole-head MEG systems using identical testing methods. Results indicate that (a) the degree of hemispheric asymmetry in the duration of neurophysiological activity in temporal and temporoparietal regions was reduced in the Chinese group, (b) the proportion of individuals who showed bilaterally symmetric activation was significantly higher in this group, and (c) group differences in functional hemispheric asymmetry were first noted after the initial sensory processing of the word stimuli. Furthermore, group differences in the degree of hemispheric asymmetry were primarily due to greater degree of activation in the right temporoparietal region in the Chinese group, suggesting increased participation of this region in the spoken word recognition in Mandarin-Chinese.

94MEIOSIS INHIBITION OF BOVINE OOCYTES: EFFECTS ON SURVIVAL AFTER VITRIFICATION BY OPEN PULLED-STRAW METHOD

Mammalian oocytes remain one of the most difficult cell types to successfully cryopreserve. The in vitro-maturation protocols (IVM) have a large impact on the oocyte maturation. Consequently, inhibition of meiosis has been used to improve developmental competence of oocytes without reducing blastocyst rates. Moreover, the meiotic stage influences the ability of oocytes to survive cryopreservation. This work analyzes the effect of the inhibition of meiosis (prematuration) on the freezability of the bovine oocyte. Cumulus-oocyte complexes (COCs) were recovered from slaughterhouse ovaries. Inmature oocytes (I) with compact cumulus and evenly granulated cytoplasm were selected. Prematuration (PM) was performed by incubating COCs for 22h in TCM199 NaHCO3 and roscovitine 25μM. IVM was accomplished in TCM199 NaHCO3, 10% FCS, FSH-LH and 17β-estradiol. Oocytes were subjected to 5 treatments prior the vitrification (see table). COCs were partially denuded from cumulus cells and vitrified/warmed using the OPS system (Vajta et al. 1998 Mol. Reprod. Dev. 51, 53–58). Warmed oocytes were fertilized (Day 0) and presumptive zygotes having a normal morphological appearance were cultured in SOFaa+5% of FCS (Day 3); elements with degenerated appearance were discarded and recorded. Fresh oocytes submitted to IVM (c-M) or prematured and matured (c-PM+M) were fertilized and cultured as controls. Data were analyzed by ANOVA and Duncan’s multiple range test and expressed as LSM±SE. Developmental data are referred to the zygotes cultured. Only oocytes vitrified after IVM reached the blastocyst stage, but at lower rates than fresh controls. However, no differences were found between treatments at any developmental stage. Oocytes vitrified both as prematured+matured and immature oocytes showed increased proportions (P&lt;0.01) of degenerated oocytes (37.3±5.9 and 49.9±5.9, respectively), as compared with oocytes matured before vitrification (17.6±5.9). These results show that effects induced by incubation with roscovitine (Lonergan et al. 2003 Mol. Reprod. Dev. 64, 369–378) in combination with cryodamage compromise the oocyte developmental ability. Supported by CICYT, AGL2001-379.

Ferromagnetism in fcc twinned 2.4 nm size Pd nanoparticles

The onset of ferromagnetism has been experimentally observed in small Pd particles of average diameter 2.4 nm. High-resolution studies reveal that a high percentage of the fcc particle exhibits single and multiple twinning boundaries. The spontaneous magnetization close to 0.02 emu/g seems to indicate that only a small fraction of atoms holds a permanent magnetic moment and contributes to ferromagnetism. The possible origin of ferromagnetism is briefly discussed according to different models recently reported.

Aggressive conservative treatment of esophageal perforations in children

BACKGROUND/PURPOSE

In contrast with adult patients in whom surgical closure of the defect is preferred, nonoperative treatment has been the usual approach for esophageal perforation (EP) in children. This report aims to assess whether this strategy stands the passage of time.

METHODS

We reviewed retrospectively the charts of 17 patients aged 5.3 +/- 0.9 years (mean +/- SD) treated at our institution for EP between 1991 and 2001.

RESULTS

Nineteen episodes of EP were caused by stricture dilation in 9 cases, foreign body extraction in 3, and blunt trauma and sclerosis of varices in 2 cases each. The remaining child had multiple gastrointestinal perforations in the course of chemotherapy for leukemia. Vigorous treatment, consisting of nasopharyngeal aspiration, wide spectrum antibiotics, prompt drainage of effusions and either parenteral or infraesophageal nutritition, was implemented immediately after diagnosis. Perforations were closed without direct surgery in 18 of 19 episodes (16 of 17 children). One or more pleural drains were inserted in 12 cases, and pericardial drainage was required once. Seven gastrostomies, 2 jejunostomies, and one esophagostomy were performed. Several major abdominal operations were necessary to repair concomitant lesions in a child who sustained severe blunt abdominal trauma and in the patient with leukemic perforations. All patients survived, and all recovered esophageal function. However, 2 with intractable lye strictures ultimately required esophageal replacement. The only patient in whom a direct approach for esophageal necrosis due to variceal endosclerosis was unavoidable, lost her organ and had a retrosternal colonic interposition after a successful portosystemic shunt. Excluding patients with other concomitant lesions and the patient who underwent surgery, median length of stay was 11 days (range, 6 to 47).

CONCLUSIONS

Prompt and aggressive nonoperative treatment of esophageal perforations in children allows survival with conservation of the organ in most cases and remains, in the authors' hands, the first therapeutic choice at this age.

Sentinel node localization in patients with non-palpable breast cancer

The aim of this study was to demonstrate that radionuclide sentinel node detection can be applied to patients with non-palpable breast cancer. One hundred and ten consecutive women with unilateral breast cancer were studied. Group 1 was made up of 80 patients with palpable breast cancer (mean age, 58 years) and group 2 of 30 patients with non-palpable breast cancer detected mammographically (mean age, 55 years). Tc-nanocolloid (111 MBq) was injected peritumorally in palpable tumours, and in the tumour area (ultrasound guided) in non-palpable tumours. At 2 h post-injection, anterior and lateral scintigrams were obtained from patients in the supine position. The location of the sentinel node was marked on the patient's skin. Patients with non-palpable tumours were moved to the surgery room 3 h later, and those with palpable tumours 24 h later. The histopathological study included three haematoxylineosin sections and immunochemistry. All patients underwent axillary lymphadenectomy. The sentinel node was detected in 67 cases (84%) in group 1 and in 28 cases (93%) in group 2. In four patients (5%) in group 1 and two patients (7%) in group 2, no axillary sentinel node was detected in the surgical bed, although it had been seen in scintigraphy. In nine patients (11%) in group 1, neither scintigraphic nor surgical detection was successful. Skip metastasis was seen in six cases (10%) of palpable tumours and in one case (4%) of non-palpable tumours. It can be concluded that non-palpable breast tumours cannot be considered an exclusion criterion for sentinel node localization and biopsy. Ultrasonography-guided injection, followed by scintigraphic and surgical detection of the sentinel node, may help in the management of patients with non-palpable breast tumours.

Dalitz plot analysis of the decay D(+)-->K(-)pi(+)pi(+) and indication of a low-mass scalar Kpi resonance

We study the Dalitz plot of the decay D(+)-->K(-)pi(+)pi(+) with a sample of 15090 events from Fermilab experiment E791. Modeling the decay amplitude as the coherent sum of known Kpi resonances and a uniform nonresonant term, we do not obtain an acceptable fit. If we allow the mass and width of the K(*)(0)(1430) to float, we obtain values consistent with those from PDG but the chi(2) per degree of freedom of the fit is still unsatisfactory. A good fit is found when we allow for the presence of an additional scalar resonance, with mass 797+/-19+/-43 MeV/c(2) and width 410+/-43+/-87 MeV/c(2). The mass and width of the K(*)(0)(1430) become 1459+/-7+/-5 MeV/c(2) and 175+/-12+/-12 MeV/c(2), respectively. Our results provide new information on the scalar sector in hadron spectroscopy.

Immunohistochemical detection of Mycoplasma agalactiae in formalin-fixed, paraffin-embedded tissues from naturally and experimentally infected goats

Samples from the mammary tissue of 14 lactating goats (12 naturally infected and two experimentally infected) were examined for the presence of Mycoplasma agalactiae. A monoclonal antibody (5G12) was applied to formalin-fixed, paraffin-wax-embedded sections and labelled by the avidin-biotin peroxidase complex (ABC) method. Histological examination of tissue sections revealed strong immunoreactivity in all animals included in the study. Mycoplasma agalactiae antigen was mainly detected in the cellular debris at the periphery of purulent exudates present within lactiferous sinuses, and lactiferous and interlobular ducts. In addition, M. agalactiae organisms appeared in the cytoplasm of the epithelium of ducts, and in infiltrating macrophages and neutrophils within the ducts, alveoli, interstitial tissue and regional lymph node sinuses. It is concluded that this monoclonal antibody-based immunohistochemical technique is an efficient and specific method for the post-mortem detection of M. agalactiae in cases of clinical mastitis as well as being a useful tool for the study of the route of infection and cellular types involved during mastitis caused by this organism.

D-2-Hydroxyglutaric aciduria in a patient with a severe clinical phenotype and unusual MRI findings

We report an infant with intermittent urinary excretion of D-2-hydroxyglutaric (D-2-OHG) acid who died at the age of 10 months from cardiogenic shock due to cardiomyopathy. High urinary concentrations of D-2-OHG and succinic acid, as well as increased levels of lactic acid were detected on three different occasions, whereas a normal urinary profile of organic acids was found on one occasion. The clinical findings of our patient consisted of generalized hypotonia, irritability, developmental delay, generalized tonic seizures, lethargy, cardiomyopathy, and respiratory distress. Cerebral MRI revealed bilateral lesions in the substantia nigra, the periaqueductal area, the medial part of the thalamus, the hypothalamus, the caudate nucleus, putamen and globus pallidus. This pattern is suggestive of a mitochondriopathy. However, respiratory chain enzyme activities were normal in fibroblasts. Exogenous supplementation of D-2-OHG acid strongly inhibited cytochrome-c oxidase activity in fibroblasts from the patient and from normal controls in vitro. The results suggest that our patient has an unusual form of D-2-hydroxyglutaric aciduria (D-2-OHGA), different from the patients published so far, and that the increase of lactic acid and some citric acid cycle intermediates encountered in some patients with D-2-OHGA may be due to a functional defect of the respiratory chain caused by D-2-OHG acid.

Multicenter study on spreading of the tet(M) gene in tetracycline-resistant Streptococcus group G and C isolates in Argentina

A prospective multicenter study on invasive infections caused by beta-hemolytic streptococci was performed over 6 months and involved 42 centers from 16 cities in Argentina. Among 33 isolates recovered, 9 group G Streptococcus isolates (39.1%) and 2 group C Streptococcus isolates (20%) exhibited resistance to tetracycline and harbored the tet(M) gene. Genealogical analysis revealed that tetracycline resistance has a polyclonal origin in Argentina.

A protein G fragment from the salmonid viral hemorrhagic septicemia rhabdovirus induces cell-to-cell fusion and membrane phosphatidylserine translocation at low pH

The fusion-related properties of segments p9, p3, p4, and p9 + p2 surrounding the p2 phospholipid-binding domain of the protein G (pG) of the salmonid rhabdovirus of viral hemorrhagic septicemia (VHS) (Nuñez, E., Fernandez, A. M., Estepa, A., Gonzalez-Ros, J. M., Gavilanes, F., and Coll, J. M. (1998) Virology 243, 322-330; Estepa, A., and Coll, J. M. (1996) Virology 216, 60-70), have been studied at neutral and fusion (low) pH values by using its derived peptides. Cell-to-cell fusion, translocation of phosphatidylserine, and inhibition of fusion of pG-transfected cells defined the p9 + p2 (fragment 11, sequence 56-110) as a fragment with higher specific activity for anionic phospholipid aggregation than the previously reported p2. While fragment 11, p2, and p3 showed interactions with anionic phospholipids, p9 and p4 showed no interactions with any phospholipids. When added to a cell monolayer model at low pH, fragment 11 induced pH-dependent cell-to-cell fusion and translocated phosphatidylserine from the inner to the outer leaflet of the membrane. At low pH and in the presence of anionic phospholipids, fragment 11 showed more than 80% beta-sheet conformation (IR and CD spectroscopies). Finally, anti-fragment 11 antibodies inhibited low pH-dependent pG-transfected cell-to-cell fusion. All of the data support the conclusion that fragment 11 is a primary determinant of some of the viral cell fusion events in VHSV.

Bilateral diaphragmatic paralysis after open heart surgery

The purpose of the present case report is to present a case of bilateral diaphragmatic paralysis as a complication of open-heart surgery. A 47-year-old male was operated for aortic and mitral valve replacement. After discontinuation of sedation, bilateral diaphragmatic paralysis as well as motor and sensitive dysfunction in the four extremities was observed. The patient remained with mechanical ventilation support for twenty months. Two years after the operation a complete normalisation of the diaphragmatic motion was observed. Although uncommon, bilateral diaphragmatic paralysis after open-heart surgery could take place, being necessary long term mechanical ventilation support until recovery.

Effects of tactile-kinesthetic stimulation in preterms: a controlled trial

BACKGROUND

To determine the effects of tactile-kinesthetic stimulation to preterms on physiologic parameters, physical growth and behavioral development.

DESIGN

Controlled trial.

SETTING

The premature unit (growing nursery) of a large, teaching hospital.

SUBJECTS

48 well preterms with birth weights between 1000-2000 grams.

INTERVENTION

The neonates were systematically allocated into test and control groups. Test babies received tactile-kinesthetic stimulation in the form of a structured baby massage from day 3 to term corrected age. They were observed for changes in vital parameters (heart rate, respiration, temperature and oxygen saturation) during the first few days of stimulation in hospital. Thereafter, massage was continued at home. Changes in weight, length and head circumference and neuro-behavior (Brazelton Neuro-Behavioral Assessment Scale) were assessed in both groups before, during and after the study period.

RESULTS

An increase in heart rate (within physiologic range) was seen in the test group during stimulation. This group also showed a weight gain of 4.24 g/day more than controls, which was statistically significant. On the Brazelton Scale the test group showed statistically significant improved scores on the "orientation", "range of state", "regulation of state" and "autonomic stability" clusters at follow-up. No significant complications were noted. A positive correlation was found between the duration of stimulation in days and the weight gain in grams but this did not reach statistical significance.

CONCLUSIONS

Tactile-kinesthetic stimulation when administered to well, preterm infants has a beneficial effect on growth and behavioral development with no adverse effects on physiologic parameters.

Intravenous metronidazole for the treatment of Clostridium difficile colitis

PURPOSE

Severe Clostridium difficile colitis may produce abdominal distention and ileus, precluding oral antibiotic therapy. Stimulated by several case reports in which intravenous metronidazole was used, we reviewed our experience.

METHODS

Using pharmacy and microbiology laboratory records, we retrospectively identified patients with C. difficile colitis who received intravenous metronidazole as initial monotherapy. To be included, patients had to fulfill the following criteria: 1) at least six doses (equivalent to two days of therapy) of intravenous metronidazole were administered, 2) no other potential cause for colitis was found, and 3) the diagnosis of C. difficile colitis was firmly established. For eligible patients, five clinical parameters were assessed before and after intravenous metronidazole.

RESULTS

Our patient group (n = 10) received an average of 13.7 (range, 6-24) doses of intravenous metronidazole as initial therapy for C. difficile colitis. All received a dose of 500 mg three times daily. The majority of patients with vomiting, fever, and/or abdominal pain present at the beginning of therapy had resolution with intravenous metronidazole. Only one patient developed a symptom (vomiting) while on therapy; however, this eventually resolved when oral metronidazole was instituted. No patient required colectomy for refractory colitis or developed toxic megacolon. No patient, including those on prolonged courses, developed toxicity related to intravenous metronidazole such as peripheral neuropathy.

CONCLUSIONS

Intravenous metronidazole may be effective therapy in patients with C. difficile colitis. A randomized, prospective study appears warranted.

Heterogeneity of angiogenic activity in a human liposarcoma: a proposed mechanism for "no take" of human tumors in mice

BACKGROUND

Tumor cells are known to be heterogeneous with respect to their metastatic activity, proliferation rate, and activity of several enzymes. However, little is known about the heterogeneity of tumor angiogenic activity. We investigated whether heterogeneity of angiogenic activity could be responsible for the well-known observation of "no take" of human tumors transplanted into immunodeficient mice.

METHODS

Severe combined immunodeficient (SCID) mice were xenotransplanted subcutaneously with tumor tissue (n = 55) or cell suspension of a human liposarcoma cell line (SW-872) or subclones (n = 28), with varying cell proliferation rates. Xenograft tumor growth was recorded for up to 6 months. Tumor tissues were then removed and analyzed for tumor cell apoptosis, microvessel density, and cell proliferation. All statistical tests were two-sided.

RESULTS

Pieces of tumor derived from the parental cell line or its clones gave rise to three kinds of tumors: 1) highly angiogenic and fast-growing (aggressive) tumors, 2) weakly angiogenic and slow-growing tumors, and 3) nonangiogenic and stable tumors. Most tumors retained the original phenotype of their parental tumor. Tumor volume correlated positively with microvessel density (Spearman correlation coefficient [r] =.89; P< or =.0001) and inversely with tumor cell apoptosis (Spearman r = -.68; P =.002). Tumor volume was less strongly but still positively correlated with tumor cell proliferation in vivo (Spearman r =.55; P =.02).

CONCLUSIONS

Human liposarcoma cells appear to be heterogeneous in their angiogenic activity. When tumor cells with little or no angiogenic activity are transplanted into SCID mice, a microscopic, dormant tumor results that may not grow further. Because such tiny tumors are neither grossly visible nor palpable, they have previously been called "no take." The finding that an angiogenic tumor can contain subpopulations of tumor cells with little or no angiogenic activity may provide a novel mechanism for dormant micrometastases, late recurrence, and changes in rate of tumor progression.

Hydrogen peroxide effects on Streptococcus thermophilus CNRZ368 cell viability

Streptococcus thermophilus CNRZ368 is an anaerobic aerotolerant bacteria and its ability to survive under aerobic growth conditions raises the question of the existence of a putative defence system against oxidative stress. Thus, survival of CNRZ368 in the presence of increasing concentrations of hydrogen peroxide was studied. Moreover, the influence of the physiologic state of the cells, as well as that of a preexposition with sublethal doses of hydrogen peroxide, upon S. thermophilus CNRZ368 survival were determined. The results suggest that S. thermophilus displays a defence system against oxidative stress and that this system is inducible.

Observation of color-transparency in diffractive dissociation of pions

We have studied the diffractive dissociation into dijets of 500 GeV/c pions scattering coherently from carbon and platinum targets. Extrapolating to asymptotically high energies (where t(min)-->0), we find that when the per-nucleus cross section for this process is parametrized as sigma = sigma0Aalpha, alpha has values near 1.6, the exact result depending on jet transverse momentum. These values are in agreement with those predicted by theoretical calculations of color-transparency.

Direct measurement of the pion valence-quark momentum distribution, the pion light-cone wave function squared

We present the first direct measurements of the pion valence-quark momentum distribution which is related to the square of the pion light-cone wave function. The measurements were carried out using data on diffractive dissociation of 500 GeV/c pi(-) into dijets from a platinum target at Fermilab experiment E791. The results show that the /q&q> light-cone asymptotic wave function describes the data well for Q2 approximately 10 (GeV/c)(2) or more. We also measured the transverse momentum distribution of the diffractive dijets.

Search for rare and forbidden Charm Meson decays D0 --> Vl+l- and hhll

We report results of a search for flavor-changing neutral current (FCNC), lepton flavor, and lepton-number violating decays of the D0 (and its antiparticle) into three and four bodies. Using data from Fermilab charm hadroproduction experiment E791, we examine modes with two leptons (muons or electrons) and a rho(0), K( *0), or straight phi vector meson or a nonresonant pi(pi), Kpi, or KK pair of pseudoscalar mesons. No evidence for any of these decays is found. Therefore, we present branching-fraction upper limits at 90% confidence level for the 27 decay modes examined (18 new).

Crosstalk between cell cycle regulators and the myogenic factor MyoD in skeletal myoblasts

During the early process of skeletal muscle differentiation, myogenic factors are not only involved in muscle-specific gene induction but also in regulating the transition from the proliferative stage, when MyoD and Myf5 are already expressed, to the orderly exit from the cell division cycle. This key step in skeletal muscle differentiation involves the down-regulation of cell cycle activators such as cyclins and cdks, and up-regulation of cell cycle inhibitors such as Rb, p21, p27, and p57. In particular, Rb and p21 have been shown to play an important role in the growth arrest of differentiating myoblasts. Their level and/or activity, while being negatively controlled by growth factors, appear to be positively linked with the myogenic factor MyoD, which plays a cooperative role in the induction of growth arrest. MyoD can block proliferation independently of its transcriptional activity. Therefore, the interplay between G1 cyclins and cdk inhibitors, on the one hand, and MyoD and its co-factors, on the other, plays a critical role in myoblast cell cycle withdrawal. Accurate synchronization of dividing myoblasts revealed that MyoD and Myf5 are themselves subject to specific cell cycle-dependent regulation, with MyoD at its highest level in early G1 and its lowest level at the G1 to S phase transition. The time-window when cells exit their cycle into differentiation is in G1, when MyoD is maximal and Myf5 is down. In contrast, quiescent non-differentiating myoblasts (i. e., in G0) present an opposite pattern for the two factors: high Myf5 and no MyoD. Several recent studies have focused on MyoD phosphorylation and its potential role in ubiquitination-mediated degradation of the protein. Linking this phosphorylation to the cell cycle-dependent drop in MyoD protein before S phase leads, to a mechanism implying cdk2-cyclin E and its inhibitors (p57kip and p21cip) in the tight control of MyoD levels and subsequent myoblast cell cycle progression or exit into differentiation.

Protein kinase B beta/Akt2 plays a specific role in muscle differentiation

Insulin-like growth factors positively regulate muscle differentiation through activation of the phosphatidylinositol 3-kinase/protein kinase B (PKB/Akt) signaling pathway. Here, we compare the role of the two closely related alpha (Akt1) and beta (Akt2) isoforms of PKB in muscle differentiation. During differentiation of C2.7 or L6D2 myoblasts, PKBbeta was up-regulated whereas expression of PKBalpha was unaltered. Although the two isoforms were found active in both myoblasts and myotubes, cell fractionation experiments indicated that they displayed distinct subcellular localizations in differentiated cells with only PKBbeta localized in the nuclei. In a transactivation assay, PKBbeta (either wild-type or constitutively active) was more efficient than PKBalpha in activating muscle-specific gene expression. Moreover, microinjection of specific antibodies to PKBbeta inhibited differentiation of muscle cells, whereas control or anti-PKBalpha antibodies did not. On the other hand, microinjection of the anti-PKBalpha antibodies caused a block in cell cycle progression in both non muscle and muscle cells, whereas anti-PKBbeta antibodies had no effect. Taken together, these results show that PKBbeta plays a crucial role in the commitment of myoblasts to differentiation that cannot be substituted by PKBalpha.

Effect of antiangiogenic therapy on slowly growing, poorly vascularized tumors in mice

BACKGROUND

Angiogenesis is essential for tumor growth and progression. Therefore, inhibition of angiogenesis is being studied as a new anticancer therapy. Because cytotoxic chemotherapy is more effective on rapidly growing tumors than on slowly growing tumors, it has been assumed that antiangiogenic therapy will also be effective only on rapidly growing, highly vascularized tumors. We compared the effects of two angiogenesis inhibitors, TNP-470 and angiostatin, on slowly growing, poorly vascularized and rapidly growing, highly vascularized human tumors in mice.

METHODS

Slowly growing (RT-4) and rapidly growing (MGH-U1) human bladder carcinoma cell lines were grown in severe combined immunodeficiency mice. Established tumors were treated with one of the two angiogenesis inhibitors. Tumor volumes, vascularity, and proliferation indices were determined. The in vitro effects of TNP-470 and of angiostatin on the proliferation of RT-4 and MGH-U1 cells were also investigated. All statistical tests were two-sided.

RESULTS

RT-4 and MGH-U1 tumor growth was statistically significantly inhibited by both angiogenesis inhibitors (P<.001). Both inhibitors decreased the blood vessel density in both tumor types but did not alter the in vivo proliferation indices of the tumors. TNP-470, but not angiostatin, marginally decreased the in vitro proliferation of MGH-U1 cells.

CONCLUSION

Slowly growing, poorly vascularized tumors in animal models respond as well as rapidly growing, highly vascularized tumors to therapy with the angiogenesis inhibitors TNP-470 and angiostatin.

Primary care physicians' experience with disease management programs

OBJECTIVE

To examine primary care physicians' perceptions of how disease management programs affect their practices, their relationships with their patients, and overall patient care.

DESIGN

Cross-sectional mailed survey.

SETTING

The 13 largest urban counties in California.

PARTICIPANTS

General internists, general pediatricians, and family physicians.

MEASUREMENTS AND MAIN RESULTS

Physicians' self-report of the effects of disease management programs on quality of patient care and their own practices. Respondents included 538 (76%) of 708 physicians: 183 (34%) internists, 199 (38%) family practitioners, and 156 (29%) pediatricians. Disease management programs were available 285 to (53%) physicians; 178 had direct experience with the programs. Three quarters of the 178 physicians believed that disease management programs increased the overall quality of patient care and the quality of care for the targeted disease. Eighty-seven percent continued to provide primary care for their patients in these programs, and 70% reported participating in major patient care decisions. Ninety-one percent reported that the programs had no effect on their income, decreased (38%) or had no effect (48%) on their workload, and increased (48%)) their practice satisfaction.

CONCLUSIONS

Practicing primary care physicians have generally favorable perceptions of the effect of voluntary, primary care-inclusive, disease management programs on their patients and on their own practice satisfaction.

Angiogenic potential of prostate carcinoma cells overexpressing bcl-2

BACKGROUND

Tumors commonly outgrow their blood supply, thereby creating hypoxic conditions, which induce apoptosis and increase expression of angiogenic growth factors. The bcl-2 oncogene inhibits apoptosis induced by a variety of stimuli, including hypoxia. On the basis of bcl-2's role in regulating apoptosis in response to hypoxia, we hypothesized that this oncogene might affect other responses to hypoxia, such as the expression of angiogenic growth factors.

METHODS

Three prostate carcinoma cell lines, PC3, LNCaP, and DU-145, were stably transfected with a bcl-2 complementary DNA (cDNA), and transfectants were analyzed in vitro for the expression of angiogenic factors after exposure to either normoxic (19% O(2)) or hypoxic (1% O(2)) conditions. The in vivo angiogenic potential of the transfected cells was determined by analyzing vessel density in xenografts derived from them and by measuring the ability of these xenografts to induce neovascularization when implanted in mouse corneal micropockets. Statistical tests were two-sided.

RESULTS

When exposed to hypoxic conditions, prostate carcinoma cells overexpressing bcl-2 expressed statistically significantly higher levels of vascular endothelial growth factor (VEGF), an angiogenic factor, than control-transfected cells (P = .001 for PC3, P = .04 for DU-145 after 48 hours). This effect of bcl-2 was independent of its antiapoptotic activity because increased expression of VEGF was detected in PC3 cells overexpressing bcl-2 even though PC3 cells are inherently resistant to hypoxia-induced apoptosis. In vivo, xenograft tumors derived from the bcl-2-overexpressing prostate carcinoma cell lines displayed increased angiogenic potential and grew more aggressively than tumors derived from the control cell lines (P =.03 for PC3). Treatment of bcl-2-overexpressing and control tumors with the antiangiogenic drug TNP-470 neutralized the aggressive angiogenesis in bcl-2-overexpressing tumors (P = .04 for PC3, P = .004 for DU-145) and the moderate angiogenesis in control tumors (P = .01 for PC3, P = .05 for DU-145), resulting in similar growth rates for both tumors.

CONCLUSIONS

bcl-2 may play a dual role in tumorigenesis by suppressing apoptosis and by stimulating angiogenesis.

Study of the D(+)(s)-->pi(-)pi(+)pi(+) decay and measurement of f(0) masses and widths

From a sample of 848+/-44 D(+)(s)-->pi(-)pi(+)pi(+) decays, we find gamma(D(+)(s)-->pi(-)pi(+)pi(+))/gamma(D(+)(s)-->straight phipi(+)) = 0.245+/-0.028(+0.019)(-0.012). Using a Dalitz plot analysis of this three body decay, we find significant contributions from the channels rho(0)(770)pi(+), rho(0)(1450)pi(+), f(0)(980)pi(+), f(2)(1270)pi(+), and f(0)(1370)pi(+). We also present the values obtained for masses and widths of the resonances f(0)(980) and f(0)(1370).

Experimental evidence for a light and broad scalar resonance in D(+) --> pi(-)pi(+)pi(+) decay

From a sample of 1172 +/- 61 D(+)-->pi(-)pi(+)pi(+) decays, we find gamma(D(+)-->pi(-)pi(+)pi(+))/gamma(D(+)-->K-pi(+)pi(+)) = 0.0311 +/- 0.0018(+0.0016)(-0.0026). Using a coherent amplitude analysis to fit the Dalitz plot of these decays, we find strong evidence that a scalar resonance of mass 478(+24)(-23) +/- 17 MeV/c(2) and width 324(+42)(-40) +/- 21 MeV/c(2) accounts for approximately half of all decays.

[Neuropsychology of temporal partial epilepsy: a comparison of drug resistant and pharmacologically controlled patients]

INTRODUCTION

Various factors may contribute to cognitive deterioration in temporal lobe epilepsy, and there is controversy as to which has the greatest effect.

PATIENTS AND METHODS

In this study, we establish a comparison between patients with temporal lobe epilepsy controlled by drugs and drug-resistant patients, with the object of discovering the effect of different factors in causing cognitive damage.

RESULTS

The persons whose disorder was controlled by pharmacological means had better results in memory and intelligence tests than those with drug-resistance. The latter had alterations of declarative memory for verbal material (left) and for visio-spatial material (right) in delayed free recall tests. Also, the greater proportion of symptomatic epilepsies in the drug-resistant group affected their greater cognitive deterioration.

CONCLUSIONS

Our results show that having long-standing epilepsy with great frequency of seizures and symptomatic epilepsy is correlated with cognitive alterations in memory function in temporal lobe epilepsy. Most deterioration is seen in patients with long-standing drug resistant symptomatic left mesial temporal epilepsy.

Friend or foe? How primary care physicians perceive hospitalists

BACKGROUND

Increased use of hospitalists is redefining the role of primary care physicians. Whether primary care physicians welcome this transition is unknown. We examined primary care physicians' perceptions of how hospitalists affect their practices, their patient relationships, and overall patient care.

METHODS

A mailed survey of randomly selected general internists, general pediatricians, and family practitioners with experience with hospitalists practicing in California.

MAIN OUTCOME MEASURES

Physicians' self-reports of hospitalists' effects on quality of patient care and on their own practices.

RESULTS

Seven hundred eight physicians were eligible for this study, and there was a 74% response rate. Of the 524 physicians who responded, 34% were internists, 38% were family practitioners, and 29% were pediatricians. Of the 524 respondents, 335 (64%) had hospitalists available to them and 120 (23%) were required to use hospitalists for all admissions. Physicians perceived hospitalists as increasing (41%) or not changing (44%) the overall quality of care and perceived their practice style differences as neutral or beneficial. Twenty-eight percent of primary care physicians believed that the quality of the physician-patient relationship decreased; 69% reported that hospitalists did not affect their income; 53% believed that hospitalists decreased their workload; and 50% believed that hospitalists increased practice satisfaction. In a multivariate model predicting physician perceptions, internists, physicians who attributed loss of income to hospitalists, and physicians in mandatory hospitalist systems viewed hospitalists less favorably.

CONCLUSIONS

Practicing primary care physicians have generally favorable perceptions of hospitalists' effect on patients and on their own practice satisfaction, especially in voluntary hospitalist systems that decrease the workload of primary care physicians and do not threaten their income. Primary care physicians, particularly internists, are less accepting of mandatory hospitalist systems. Arch Intern Med. 2000;160:2902-2908

[Bact-Alert system for hemocultures: evaluation of terminal subcultures]

Few laboratory microbiological procedures are as important as the isolation of microorganisms from blood. To evaluate the usefulness of the terminal subcultures, 5669 blood cultures giving negative results after 7 days of incubation in the Bact/Alert System (Organon Teknika) were studied. Bottles were distributed as follows: 1562 adult aerobic bottles, 119 adult anaerobic bottles, 3960 pediatric bottles and 28 FAN bottles. From 5669 blood cultures, 10 subcultures that yielded growth had not been detected by the system. These included 5 adult aerobic bottles and 5 pediatric bottles, 7 of these microorganisms were considered contaminants according to clinical data (2 Micrococcus spp, 1 staphylococci coagulase negative, 1 Burkholderia cepacia, 1 Peptoestreptococcus spp, 1 Corynebacterium spp, 1 Scedosporium spp) while the other 3 were considered true bacteremia (1 Pseudomonas aeruginosa, 1 Proteus mirabilis, 1 Streptococcus sanguis), although no one made any change in treatment on the basis of the previous isolation. Based on these results the routinary utilization of terminal subcultures is not advisable and should be used only for special cases or a second system of blood culture should be added according to clinical or epidemiological data.

Research on factors allowing a risk assessment of spore-forming pathogenic bacteria in cooked chilled foods containing vegetables: a FAIR collaborative project

Vegetables are frequent ingredients of cooked chilled foods and are frequently contaminated with spore-forming bacteria (SFB). Therefore, risk assessment studies have been carried out, including the following: hazard identification and characterisation--from an extensive literature review and expertise of the participants, B. cereus and C. botulinum were identified as the main hazards; exposure assessment--consisting of determination of the prevalence of hazardous SFB in cooked chilled foods containing vegetables and in unprocessed vegetables, and identification of SFB representative of the bacterial community in cooked chilled foods containing vegetables, determination of heat-resistance parameters and factors affecting heat resistance of SFB, determination of the growth kinetics of SFB in vegetable substrate and of the influence of controlling factors, validation of previous work in complex food systems and by challenge testing and information about process and storage conditions of cooked chilled foods containing vegetables. The paper illustrates some original results obtained in the course of the project. The results and information collected from scientific literature or from the expertise of the participants are integrated into the microbial risk assessment, using both a Bayesian belief network approach and a process risk model approach, previously applied to other foodborne hazards.

Efficacy of antiangiogenic therapy with TNP-470 in superficial and invasive bladder cancer models in mice

OBJECTIVES

To evaluate the efficacy of antiangiogenic therapy with O-(chloracetyl-carbamoyl) fumagillol (TNP-470) in a superficial and an invasive bladder cancer model in mice. The control of recurrent superficial and metastatic bladder cancer constitutes a major problem in urologic practice. Although the established therapies for these cases (immunotherapy, chemotherapy, and radiation therapy) have improved during the previous decades, further improvement and the reduction of existing side effects are needed. The inhibition of angiogenesis represents a new concept in cancer therapy.

METHODS

We evaluated the in vitro effect of TNP-470 on the proliferation of bovine capillary endothelial cells (BCE), the superficial transitional cell carcinoma (TCC) cell line (KK-47), and the invasive TCC cell line (MGH-U1). To evaluate the in vivo effect of TNP-470 on the growth of advanced TCCs, both cell lines were injected subcutaneously into SCID mice. When tumors grew to a size of 100 to 200 mm(3), therapy either with TNP-470 or phosphate-buffered saline was initiated.

RESULTS

TNP-470 strongly inhibited endothelial cell proliferation in vitro. The in vitro proliferation of both bladder carcinoma cell lines was also inhibited by TNP-470. However, the doses inhibitory to bladder carcinoma cells were 100-fold higher than the doses that were effective in the inhibition of endothelial cell proliferation. In vivo, TNP-470 significantly inhibited the growth of advanced KK-47 (67%) and MGH-U1 (68%) tumors in SCID mice.

CONCLUSIONS

Our results indicate that antiangiogenic therapy with TNP-470 is equally effective in advanced superficial and invasive bladder carcinoma models in mice. When our results are taken together with the reports of other laboratories, TNP-470 appears to be a promising candidate as a tumor suppressor in superficial and invasive bladder cancer.

Intensive care during prolonged anhepatic state after total hepatectomy and porto-caval shunt (two-stage procedure) in surgical complications of liver transplantation

BACKGROUND/AIMS

Recently, total hepatectomy and temporary porto-caval shunt has been indicated in surgical complications of liver transplantation. Four cases of liver transplantation which presented liver hemorrhage at the time of implant, and a 5th case with surgical trauma of hepatic hilum are presented.

METHODOLOGY

The graft was removed and a porto-caval shunt was performed in all patients. Retransplantation was possible in all recipients, after an anhepatic period of 16-24 hours.

RESULTS

Early persistent ionic hypocalcemia and late olyguric renal failure were the most constant and prominent complications during the anhepatic period. Two patients died of renal failure and respiratory distress syndrome at 6 and 28 days, respectively, after liver transplantation. The other 3 patients are alive and without complications at 48, 33 and 11 months of follow-up.

CONCLUSIONS

Total hepatectomy with a temporary porto-caval shunt and later retransplantation must be considered as a useful procedure for surgical complications of liver transplantation which may not be treated using other techniques. Special attention should be paid to preserve renal function in the anhepatic state in order to improve survival in similar cases of two-stage liver transplantation.