Distinct Nature of Static and Dynamic Magnetic Stripes in Cuprate Superconductors

We present detailed neutron scattering studies of the static and dynamic stripes in an optimally doped high-temperature superconductor, La_{2}CuO_{4+y}. We observe that the dynamic stripes do not disperse towards the static stripes in the limit of vanishing energy transfer. Therefore, the dynamic stripes observed in neutron scattering experiments are not the Goldstone modes associated with the broken symmetry of the simultaneously observed static stripes, and the signals originate from different domains in the sample. These observations support real-space electronic phase separation in the crystal, where the static stripes in one phase are pinned versions of the dynamic stripes in the other, having slightly different periods. Our results explain earlier observations of unusual dispersions in underdoped La_{2-x}Sr_{x}CuO_{4} (x=0.07) and La_{2-x}Ba_{x}CuO_{4} (x=0.095).

Developing tailored positive parenting messages for a clinic-based communication programme

BACKGROUND

Health care providers fill a central role in the prevention of both child abuse and neglect (CA/N) and unintentional childhood injury. Health communication interventions hold promise for promoting attitudes and behaviours among parents that increase positive parenting practices, which may be linked to decreased rates of intentional and unintentional childhood injuries. This manuscript describes the development of 'RISE Up', an ambulatory clinic-based childhood injury prevention programme that provides tailored, injury prevention print materials to parents of children ages 0-5.

METHODS

Fifteen semi-structured key informant interviews were conducted with clinic healthcare providers and staff to develop communication strategies and materials for caregivers. Cognitive response testing was then conducted with 20 caregivers of the priority population to assess all materials. Interviews were recorded, transcribed and analyzed using thematic coding methods.

RESULTS

Formative research revealed that health care providers and caregivers were very responsive to messages and materials. Health care providers reported that abuse and neglect were particularly relevant to their patients and noted several benefits to implementing the RISE Up programme in a health care setting. Caregivers generally found messages on reducing the risks of injuries, as well as the graphics displayed in the RISE Up programme to be helpful.

CONCLUSIONS

Addressing the common determinants of both intentional and unintentional childhood injury through customized print materials may be a useful component of comprehensive prevention efforts to address childhood injury risk with greater impact. Providers and parents responded favourably to this communication strategy.

Applying cognitive response testing in message development and pre-testing

Pre-testing messages with audience members is a critical step in the creation of effective health information. Quantitative methods for message testing have limited effectiveness, as they cannot reveal complications with language and comprehension. Cognitive response testing (CRT), a form of qualitative research, allows the interviewer to probe for deeper understanding of comprehension and language by asking participants to paraphrase items, discuss thoughts or emotions that come to mind and offer suggestions for improvement. This study explores the usefulness of CRT in message development and testing, adding to the literature regarding qualitative methods in public health. CRT was employed to evaluate health messages on two topics-bioterrorism and influenza vaccination. This technique effectively identified message terminology and concepts that respondents found unfamiliar or confusing, providing the framework needed for message revision. Commonly misunderstood words were replaced and confusing concepts were explained in the revised messages, making pre-tested messages more likely to be appropriate for the intended audience. These findings are consistent with previous research that establishes the usefulness of CRT in the evaluation and development of health-related messages and surveys.

Characterization of high molecular weight plasma protein complexes induced by clotting factor rFXIII-treatment in the cynomolgus monkey

BACKGROUND

In cynomolgus monkeys, suprapharmacological doses of clotting recombinant factor XIII (rFXIII) cause a generalized coagulopathy, associated with formation of circulating high molecular weight protein complexes (HMEX). HMEX consist of plasma protein substrates cross-linked by FXIII transglutaminase activity.

OBJECTIVE

To characterize HMEX, with a view to develop safety biomarker assays.

METHODS

Cynomolgus monkeys received single i.v. injections with vehicle or rFXIII at 1, 3 and 10 mg kg(-1). Plasma HMEX were analyzed by sodium dodecylsulfate-polyacrylmide gel electrophoresis, silver staining, Western blotting and quantitative dissociation-enhanced lanthanide fluoroimmunoassay. Plasma FXIII antigen was analyzed by quantitative ELISA. Human HMEX were made in vitro, by spiking plasma with thrombin-activated rFXIII.

RESULTS

Maximal circulating HMEX levels were reached within 1 h of rFXIII treatment, and remained stable over 24 h. HMEX above 250 kDa contained fibrinogen alpha-chains and fibronectin. Fibrinogen gamma-chain was detected only in HMEX below 250 kDa. The total plasma concentration of HMEX was in the low microg mL(-1) range, distributed on less than 20 main species. Human and cynomolgus HMEX were similar. HMEX formation increased with rFXIII dose in a disproportionate manner, with 3-fold and fortyfold increases in HMEX exposure associated with rFXIII dose increments from 1 to 3 and 3 to 10 mg kg(-1), respectively.

CONCLUSIONS

The disproportionate HMEX formation parallels the steep toxicity dose response previously reported for rFXIII in cynomolgus monkeys, supporting a mechanistical role for HMEX in the generalized coagulopathy seen in rFXIII toxicity. Our findings support that HMEX constitute candidate (potential) safety biomarkers in rFXIII treatment.

Identification of nuclear spliceosomal antigens targeted by NOD mouse antibodies following sodium iodide intake

The non-obese diabetic (NOD) mouse spontaneously develops a range of autoreactive responses including an autoantibody response to nuclear antigens. As elevated dietary iodine has been shown to increase thyroid autoimmune pathology in NOD mice, the effect of sodium iodide (NaI) on the development of anti-nuclear antibodies (ANA) was assessed. Interestingly, the NaI symporter is expressed in both thyroid and salivary glands. Elevated dietary iodine was found to increase the percentage of male NOD mice developing autoantibodies. Specifically, the nuclear autoantibodies that develop in NOD mice were shown to target specific spliceosomal components. The target specificity of the autoantibodies was determined using recombinant spliceosomal proteins and shown to include U1A, U170K, U2B'', U2A', as well as the Sm proteins D1, D2, and B. The autoantibody isotypes most consistently represented were IgG2a and IgG2b.

Description of a New all Cause Mortality Surveillance System in Sweden as a Warning System Using Threshold Detection Algorithms

A warning system has been set up to detect unusual weekly clusters of deaths by age group and municipality using all-cause Swedish death registry data. The technique for monitoring deaths by age group (<1, 1-24, 25-44, 45-64 and 65 plus) and week uses a compound smoothing technique, which calculates a baseline of expected events from retrospective data. Due to insufficient baseline data for the geographical component of the system a different algorithm, based on the Poisson distribution, was chosen to calculate expected weekly number of deaths per municipality, adjusting for municipalities with inherently higher mortality rates. This system was designed and tested during 2004 and implemented from the beginning of 2005. Threshold settings have been adjusted to provide a realistic number of weekly alerts. An evaluation of the system will be performed prospectively from the beginning of 2005 due to the lack of a gold standard for retrospective performance evaluation.

Repeated dose 28-day oral toxicity study in Wistar rats with a mixture of five pesticides often found as residues in food: alphacypermethrin, bromopropylate, carbendazim, chlorpyrifos and mancozeb

Six dose groups of 8 male and female rats respectively received a daily dose equivalent to 0, 0.15, 0.006, 0.03, 0.15 or 0.3 mg/kg b.w./day chlorpyrifos (groups 1-6) and the last four dose groups (groups 3-6) received in addition daily doses equivalent to 18 mg/kg b.w./day alphacypermethrin, 30 mg/kg b.w./day bromopropylate, 45 mg/kg b.w./day carbendazim and 12.5 mg/kg b.w./day mancozeb for 28 days. Plasma acetylcholinesterase was significantly decreased in the groups 2, 5 and 6 males. Total white blood cell count was significantly lower in females of group 6. Total red blood cell count, haematocrite and haemoglobin concentration was significantly reduced in both male and female rats of groups 5 and 6. Relative liver weight was significantly increased in groups 3-6 male and female rats. Absolute thyroid gland weight was significantly increased in groups 3, 5 and 6 male rats and of groups 3-6 female rats, and relative thyroid gland weight was significantly increased in groups 2-6 male rats and of groups 3-6 female rats. Absolute thymus weight of groups 3-6 male and female rats and relative thymus weight of groups 3-6 male rats and groups 3 and 4 female rats was significantly decreased. A mild degree of centrilobular cell hypertrophy of the liver was seen in all male rats and of three female rats of group 6. In the thyroid gland follicular cell hypertrophy was present in one female in the control group and in six females and seven males of group 6. It was concluded that inhibition of acetylcholinesterase activity in plasma and brain by chlorpyrifos was not enhanced by co-administration of the other four pesticides. Effects were seen in liver, thyroid, thymus and blood in the combination groups. However, identification of the pesticide(s) responsible for these changes would require further studies of the individually pesticides as well as various combinations of the pesticides.

A method to reduce the invasiveness of fetal catheterization in the cow

Surgical intervention in general anesthesia (GA) of the cow in late gestation is a stressful condition for both mother and fetus, potentially leading to premature delivery or fetal death. The present study hypothesized that fetal catheterization at days 246-253 (90% of gestation) is done with less physical and metabolic stress for the mother and fetus, when the surgery is performed on a standing cow and local anesthesia (LA) rather than on a recumbent cow in general anesthesia. Fetal and uterine maternal intra-vascular catheters were implanted during general anesthesia (GA, n=24) or local analgesia (LA, n=7). Blood gases and metabolite levels in the fetal calves and their mothers were measured during surgery and for 5 days post-operatively. During surgery, venous blood pH was higher (7.44 +/- 0.01 versus 7.39 +/- 0.01, P<0.05) and hemoglobin and oxygen contents lower in LA cows compared with GA cows (9.3 +/- 0.3 mg/dl versus 11.8 +/- 0.2 mg/dl, P<0.001 and 10.0 +/- 0.3 ml/dl versus 12.6 +/- 0.6 ml/dl, P<0.05). The differences between the two groups of fetuses reflected those of their dams in that LA fetuses showed lower arterial oxygen pressure (18.3 +/- 1.4 mmHg versus 24.8 +/- 1.4 mmHg, P<0.05) and hemoglobin (7.81 +/- 0.30 mg/dl versus 9.22 +/- 0.21 mg/dl P<0.01) and furthermore, they also showed higher blood glucose (2.4 +/- 0.2 mM versus 1.4 +/- 0.1 mM, P<0.01). During the 5 days post-surgery, 10 GA fetuses (42%) and 1 LA fetus (14%) died in utero. Bacterial contamination was implicated in six of the GA deaths and in the one LA death. In the dams with surviving calves, differences in hemoglobin (9.49 +/- 0.21 mg/dl versus 11.17 +/- 0.23 mg/dl P<0.001) and O2ct (10.9 +/- 0.3 ml/dl versus 12.5 +/- 0.5 ml/dl, P<0.05) were still present, and in addition, blood glucose was higher in LA versus GA cows (4.3 +/- 0.2 mM versus 3.8 +/- 0.1 mM, P<0.05). The choice of surgical method did not affect post-surgery blood chemistry in the surviving fetuses, except that the higher blood glucose in the LA fetuses at surgery tended to be maintained also post-operatively (2.0 +/- 0.2 mM versus 1.5 +/- 0.1 mM, P=0.07). The observed differences in blood chemistry parameters between the two methods of surgery and possibly in the fetal death may be explained by differences in catheterization method and the associated differences in physical and metabolic stress during and after surgery. Thus, surgery upon a standing cow in local anesthesia should be considered as an alternative to surgery in universal anesthesia for fetal catheterization in the cow in late gestation.

No peri- and postnatal effects on calves born after transfer of in vitro produced embryos vitrified by the open pulled straw (OPS) method

The general objective of this study was to perform follow-up studies including selected peri- and postnatal characteristics on calves born after transfer of in vitro produced (IVP) embryos vitrified by the 'Open Pulled Straw' (OPS) method. An overall pregnancy rate of 16% after transfer of the OPS-vitrified IVP embryos was achieved and resulted in birth of 9 calves, with 11 AI calves serving as controls. There were no immediate or long-term effects on these calves with respect to birth weight, gestation length, perinatal mortality, growth rate, disease susceptibility and reproductive performance.

Macromolecule absorption and cortisol secretion in newborn calves derived from in vitro produced embryos

Earlier reports indicate that calves derived from in vitro produced (IVP) embryos are more susceptible to neonatal disease than calves produced after artificial insemination (AI) or natural mating. The aims of the present study were to investigate whether calves born after IVP embryos show an altered macromolecule absorption (immunoglobulin G (IgG) and porcine serum albumin (PSA)) compared with AI calves and whether the macromolecule absorption could be related to the degree of acidosis or to the cortisol secretion around birth. Hence, IgG and PSA absorption in control AI calves (n=7) was compared with that in two groups of IVP calves (IVP-defined: SOFaa embryo culture with polyvinyl alcohol, n=6; IVP-serum: SOFaa embryo culture with serum and co-culture, n=8). The calves were fed colostrum (40ml/kg) at 2, 6 and 12h after birth. At 24h after birth, both AI and IVP calves had achieved a level of plasma IgG sufficient to provide passive immunization (>15mg/ml). When the values were adjusted for the varying colostral IgG contents and the degree of acidosis, the IVP-defined calves had significantly lower peak plasma IgG concentrations than the AI calves at 18-24h after birth (P<0.04). However, when the macromolecule marker (PSA), was fed to all calves at 2 and 12h after birth the resulting plasma PSA levels were significantly lower in the AI calves compared with the IVP calves during the whole observation period (P<0.0001). Calves with a moderate neonatal acidosis (mean pH<7.2 during the first 30min after birth) had reduced peak plasma IgG concentration at 18-24h after birth (P<0.02) compared to calves without acidosis. The basal and ACTH-stimulated cortisol levels were lower in the newborn IVP-defined calves than in the AI calves (P<0.05) and the IVP-serum calves (P<0.002). Cortisol levels shortly after birth correlated positively with birth weight (r=0.60, P<0.0001) and with gestation length (r=0.34, P<0.04). Since, the IVP calves absorbed sufficient amounts of IgG from colostrum to acquire sufficient passive immunity, we conclude that the lower viability described in IVP offspring probably is not caused by an impaired passive immunization. IVP-defined calves had significantly lower absorption efficiency of IgG compared with AI calves, whereas absorption of a non-Ig macromolecule (PSA) was higher for IVP than AI calves. This might indicate a more selective absorption in AI calves in favor of IgG. Acidosis around birth affected immunoglobulin absorption negatively. IVP-defined calves had significantly lower cortisol levels the first 3h after birth and during an ACTH-challenge and a lower IgG absorption efficiency, which might indicate a mild degree of organ dysmaturity in these calves.

Selective insolubility of alpha-synuclein in human Lewy body diseases is recapitulated in a transgenic mouse model

alpha-Synuclein (alpha-SYN) is deposited in intraneuronal cytoplasmic inclusions (Lewy bodies, LBs) characteristic for Parkinson's disease (PD) and LB dementias. alpha-SYN forms LB-like fibrils in vitro, in contrast to its homologue beta-SYN. Here we have investigated the solubility of SYNs in human LB diseases and in transgenic mice expressing human wild-type and PD-associated mutant [A30P]alpha-SYN driven by the brain neuron-specific promoter, Thy1. Distinct alpha-SYN species were detected in the detergent-insoluble fractions from brains of patients with PD, dementia with LBs, and neurodegeneration with brain iron accumulation type 1 (formerly known as Hallervorden-Spatz disease). Using the same extraction method, detergent-insolubility of human alpha-SYN was observed in brains of transgenic mice. In contrast, neither endogenous mouse alpha-SYN nor beta-SYN were detected in detergent-insoluble fractions from transgenic mouse brains. The nonamyloidogenic beta-SYN was incapable of forming insoluble fibrils because amino acids 73 to 83 in the central region of alpha-SYN are absent in beta-SYN. In conclusion, the specific accumulation of detergent-insoluble alpha-SYN in transgenic mice recapitulates a pivotal feature of human LB diseases.

Self-efficacy, state anxiety, and cortisol responses to treadmill running

Social cognitive theory of Bandura hypothesizes that increases in self-efficacy act as a mechanism for anxiety reduction and lower biological stress reactions. Therefore, the purpose of the current study was to examine self-efficacy, anxiety, and cortisol responses to 20 minutes of treadmill running at 85% maximal heart rate and a control condition among 12 physically active males. For this study, self-efficacy, anxiety, and cortisol were measured prior to and 5 and 20 min. after exercise for individuals completing a 20-min. treadmill running activity or a 20 min. rest (control) activity. Repeated-measures analyses of variance showed significant condition by time interaction for self-efficacy and cortisol (ps <.05); the exercise group's self-efficacy and cortisol increased pre- to posttreatment. Moreover, the analysis of variance for anxiety yielded a main effect for time, with reductions in anxiety scores observed in both conditions. Correlational analyses showed that posttreatment cortisol levels were inversely correlated -.51 to self-efficacy scores and positively correlated .55 to anxiety scores. The correlation between self-efficacy and anxiety was not significant. These results provide partial support for the predicted relationships among self-efficacy, anxiety, and cortisol responses to treadmill running. Suggestions for research are provided.

A possible mechanism for enantioselectivity in the chiral epoxidation of olefins with

The origin of enantioselectivity in the Jacobsen-Katsuki reaction has been investigated by applying density functional calculations in combination with molecular mechanics methodologies. The calculations suggest that a high enantiomeric excess is connected to three specific features: 1) a chiral diimine bridge, which induces folding of the salen ligand(H2salen = bis(salicylidene)ethylenediamine), and hence the formation of a chiral pocket; 2) bulky groups at the 3,3'-positions of the salen ligand, which cause a preferential approach from the side of the aromatic rings; and 3) pi conjugation of the olefinic double bond, which confers regioselectivity and, consequently, enantioselectivity. In combination with experimental studies, the model also provides a rationale for the decrease in ee values when one of these components is missing.

Edge localization of subwavelength structures by use of polarization interferometry and extreme-value criteria

A polarization interferometric method is presented for the quantitative microscopy of topographical structures with subwavelength linewidths. A liquid-crystal phase shifter is inserted into the imaging optics of a reflected-light microscope, and the principles of phase-shifting interferometry are applied to measuring the phase and the contrast of the TE-polarized image (E parallel edge) with the TM-polarized image (E perpendicular edge) as the reference. This common-path interferometric method provides selective edge detection for line structures because the polarization difference is localized at the structure edges. Two different threshold criteria for linewidth determination are discussed: distance of the contrast minima and distance of the points of the steepest phase change. Linewidths as small as 300 nm were measured at a 635-nm wavelength. The dependence on the illumination numerical aperture, as well as on the material, the width, and the depth of the structure, is investigated both experimentally and by rigorous numerical simulations.

Subcellular localization of wild-type and Parkinson's disease-associated mutant alpha -synuclein in human and transgenic mouse brain

Mutations in the alpha-synuclein (alphaSYN) gene are associated with rare cases of familial Parkinson's disease, and alphaSYN is a major component of Lewy bodies and Lewy neurites. Here we have investigated the localization of wild-type and mutant [A30P]alphaSYN as well as betaSYN at the cellular and subcellular level. Our direct comparative study demonstrates extensive synaptic colocalization of alphaSYN and betaSYN in human and mouse brain. In a sucrose gradient equilibrium centrifugation assay, a portion of betaSYN floated into lower density fractions, which also contained the synaptic vesicle marker synaptophysin. Likewise, wild-type and [A30P]alphaSYN were found in floating fractions. Subcellular fractionation of mouse brain revealed that both alphaSYN and betaSYN were present in synaptosomes. In contrast to synaptophysin, betaSYN and alphaSYN were recovered from the soluble fraction upon lysis of the synaptosomes. Synaptic colocalization of alphaSYN and betaSYN was directly visualized by confocal microscopy of double-stained human brain sections. The Parkinson's disease-associated human mutant [A30P]alphaSYN was found to colocalize with betaSYN and synaptophysin in synapses of transgenic mouse brain. However, in addition to their normal presynaptic localization, transgenic wild-type and [A30P]alphaSYN abnormally accumulated in neuronal cell bodies and neurites throughout the brain. Thus, mutant [A30P]alphaSYN does not fail to be transported to synapses, but its transgenic overexpression apparently leads to abnormal cellular accumulations.

Ease of calving, blood chemistry, insulin and bovine growth hormone of newborn calves derived from embryos produced in vitro in culture systems with serum and co-culture or with PVA

Blood chemistry (pH, pCO2, pO2, glucose, lactate) as well as plasma insulin and growth hormone of calves derived from embryos produced under 2 different in vitro culture systems (modified SOFaa with 20% serum and co-culture with bovine oviduct epithelial cells [IVP serum, n=8] or with 3 mg/mL PVA [IVPdefined, n=6]) were compared with those of calves derived from AI (n=5). Calvings were classified according to the ease (unassisted, light traction, heavy traction). Blood samples were taken from the jugular vein of calves at 5, 15, 30 and 60 min, and at 2, 3, 6, 12, 18 and 24 h after delivery, then daily for 6 d. At the second day of life after 4 feedings and a 4-h fasting period, a glucose tolerance test was performed to evaluate glucose metabolism and insulin secretion. Calves in the IVP serum group had higher birth weights than AI calves (LS mean +/- SEM, IVP serum: 45.2 +/- 1.4 kg vs AI: 40.4 +/- 1.7 kg; P < 0.05), while the birth weights of calves in the IVP defined group were in between (IVPdefined: 41.9 +/- 1.6 kg). More IVP serum calves (75%) needed assistance than IVP defined (33%) or AI (40%) calves. The effect of ease of calving vs the effect of embryo culture was compared in relation to blood parameters at birth. There was an effect of ease of calving but not of embryo culture conditions on blood pH, lactate and PCO2. Calves requiring heavy traction had lower pH during the first 3 h after calving, a higher lactate during the first 60 min after calving and a higher pCO2 the first 2 h after calving than calves born unassisted. Calves requiring heavy traction also had lower pH the first 2 h and higher lactate the first 3 h after calving than calves born by light traction. IVP defined calves had lower lactate than IVP serum calves the first 60 min after calving. At 6 h after delivery, all blood parameters had stabilized. There was no effect of either embryo culture or ease of calving on basal insulin and growth hormone level, or the ability of the calves to handle glucose postnatally and during a glucose tolerance test.

Blood chemistry, nutrient metabolism, and organ weights in fetal and newborn calves derived from in vitro-produced bovine embryos

Calves born after in vitro production (IVP) of embryos often show reduced perinatal viability. The present experiment investigated a series of physiological variables in the immediate prenatal and postnatal period of IVP dairy calves. Fetal IVP and control calves (each n = 7) were prepared with vascular catheters at 248+/-1 day gestation (term = 280 days), and blood samples were taken for five days before premature delivery by cesarean section. IVP fetuses compared with controls had significantly elevated arterial hemoglobin and oxygen content (8.41 vs. 7.52% and 5.75 vs. 3.79%, respectively) whereas lactate level was lowered (1.89 vs. 2.26 mM). The umbilical venous-arterial concentration differences in oxygen, lactate, and glucose indicated that IVP fetuses relied more on lactate and less on glucose as oxidative substrates. The fetal glucose tolerance, and the basal and adrenocorticotropin-stimulated cortisol levels were similar between the groups. In the immediate postnatal period, IVP calves showed elevated venous blood pH (7.294 vs. 7.270), hemoglobin (9.06 vs. 8.25%), oxygen contents (6.33 vs. 4. 64%), K(+) levels (4.89 vs. 4.56 mM), and rectal temperature (38.9 vs. 37.4 degrees C), and lowered blood Na(+) (139.9 vs. 141.0 mM), Cl(-) (100.2 vs. 103.1 mM) and glucose levels (2.86 vs. 3.11 mM). There were no differences in body dimensions and organ weights, except that the fore legs and hind legs were slightly longer in the IVP group (76.1 vs. 72.4 cm and 93.4 vs. 88.8 cm, respectively). Although prenatal and neonatal IVP calves differed from control calves in a number of variables, the effects were relatively minor and provide no direct evidence for the hypothesis that IVP calves have an impaired capacity to adapt to life ex utero. In fact, several parameters indicated enhanced rather than retarded maturation of IVP calves when data from premature calves were compared with data from a group of control calves delivered at term.

Body dimensions and birth and organ weights of calves derived from in vitro produced embryos cultured with or without serum and oviduct epithelium cells

Body dimensions, birth and organ weights of calves derived from embryos produced in 2 in vitro culture systems (modified SOFaa with 20% cattle serum and co-cultured with oviduct-epithelium cells [IVPserum, n=8], and modified SOFaa with 3 mg/mL PVA [IVPdefined, n=6]) were compared with calves originating from artificial insemination (AI, n=85). Three additional IVP calves were included which had been vitrified as mature oocytes by the open pulled straw (OPS) method, warmed, fertilized and cultured to the blastocyst stage in modified SOFaa with 5% cattle serum, then again OPS-vitrified and warmed prior to transfer (IVPops, n=3). At birth, gestation length and birth weights were registered for all calves. At 1 wk of age all 17 IVP and 7 of the AI calves were killed, and their body dimensions and organ weights recorded. Birth weight was higher for the IVPserum and IVPops calves than for AI control calves (kg +/- SEM: IVPserum 46.9+/-1.8, IVPops 50.6+/-2.4, AI 41.8+/-0.8; P < 0.002). There was no difference between IVP and AI calves regarding gestation length and no effect of culture conditions on body dimensions or organ weights, except for longer hind legs in IVPdefined calves compared with AI calves (cm +/- SEM: IVPdefined 93+/-2, AI 87+/-2; P < 0.04). The IVPops calves had an increased liver weight compared with AI and the other IVP calves (g +/- SEM: IVPops 1.457+/-59; AI 1,117+/-37; IVPserum 1,159+/-34, IVPdefined 1,073+/-39; P < 0.0003). It is concluded that in vitro culture of bovine embryos in the presence of serum and oviduct epithelium cells increased birth weight but not organ weight and body dimension in 1-wk-old calves. However, vitrification of the ova as oocyte and again as blastocysts increased birth weight and liver size. This possible effect of cryopreservation of oocytes on subsequent fetal development awaits further investigation.

Clinical, cognitive and functional characteristics of long-stay patients with schizophrenia: a comparison of VA and state hospital patients

Long-stay patients constitute a small proportion of all patients with schizophrenia, but in both VA and state psychiatric systems these patients account for a majority of the costs associated with treatment of the illness. VA and state patients would be expected to differ in several respects, including age at onset and premorbid educational status. Little additional information is available about the differences between these samples. Seventy-four long-stay male patients at a chronic state psychiatric center were compared with 50 male veterans from long-stay psychiatric facilities on positive and negative symptoms, cognitive deficits and functional status. The two samples did not differ on positive symptom severity, but the state patients had more severe negative and cognitive symptoms as well as functional deficits. Of all of the variables measured, deficit in self care was the only variable that entered a stepwise discriminant analysis. The correlation between functional and symptomatic variables was the same in both groups, and the group differences and correlations were not influenced by differences in educational status. These data indicate that VA patients may have reduced severity of functional and cognitive impairments relative to state hospital patients, but that the relationship between the different illness variables was similar in the two groups.

Radical Intermediates in the Jacobsen - Katsuki Epoxidation

Insight into the controversial mechanism of the Mn - salen-catalyzed epoxidation of olefins is provided in a theoretical study based on density functional theory. The calculations suggest that radical species A, but not manganaoxetanes B, are likely candidates for viable intermediates.

The influence of endoproteolytic processing of familial Alzheimer's disease presenilin 2 on abeta42 amyloid peptide formation

Mutant presenilins (PS) contribute to the pathogenesis of familial Alzheimer's disease (FAD) by enhancing the production of Abeta42 from beta-amyloid precursor protein. Presenilins are endoproteolytically processed to N-terminal and C-terminal fragments, which together form a stable 1:1 complex. We have mapped the cleavage site in the PS2 protein by direct sequencing of its C-terminal fragment isolated from mouse liver. Three different N-terminal residues were identified starting at Val-299, Thr-301, and Leu-307 that correspond closely to the previously described N termini of the C-terminal fragment of human PS1. Mutational analysis of the PS2 cleavage site indicates that the principal endoproteolytic cleavage occurs at residues Met-298/Val-299 and that the N terminus is subsequently modified by secondary proteolytic cleavages. We have generated cleavage defective PS2 constructs, which accumulate exclusively as full-length polypeptides in transfected Neuro2a cells. Functional analysis of such cleavage defective PS2 carrying the FAD mutation Asn-141 --> Ile showed that its Abeta42 producing activity was strongly reduced compared with cleavage-competent FAD PS2. In contrast, cleavage defective PS2 was active in rescuing the egg-laying defect of a sel-12 mutant in Caenorhabditis elegans. We conclude that PS2 endoproteolytic cleavage is not an absolute requirement for its activities but may rather selectively enhance or stabilize its functions.

Amyloidogenic function of the Alzheimer's disease-associated presenilin 1 in the absence of endoproteolysis

Alzheimer's disease (AD) is characterized by the invariant accumulation of senile plaques predominantly composed of the pathologically relevant 42-amino acid amyloid beta-peptide (Abeta42). The presenilin (PS) proteins play a key role in Abeta generation. FAD-associated mutations in PS1 and PS2 enhance the production of Abeta42, and PS1 is required for physiological Abeta production, since a gene knockout of PS1 and dominant negative mutations of PS1 abolish Abeta generation. PS proteins undergo endoproteolytic processing, and current evidence indicates that fragment formation may be required for the amyloidogenic function of PS. We have now determined the sequence requirements for endoproteolysis of PS1. Mutagenizing amino acids at the previously determined major cleavage site (amino acid 298) had no effect on PS1 endoproteolysis. In contrast, mutations or deletions at the additional cleavage site around amino acid 292 blocked endoproteolysis. The uncleavable PS1 derivatives accumulated as full-length proteins and replaced the endogenous PS1 proteins. In contrast to the previously described aspartate mutations within transmembrane domains 6 and 7, the uncleaved PS1 variants do not act as dominant negative inhibitors of Abeta production. Moreover, when a FAD-associated mutation (M146L) was combined with a mutation blocking endoproteolysis, Abeta42 production still reached pathological levels. These data therefore demonstrate that endoproteolysis of presenilins is not an absolute prerequisite for the amyloidogenic function of PS1. These data also show that accumulation of the PS1 holoprotein is not associated with the pathological activity of PS1 mutations as suggested previously.

Full-term development of nuclear transfer calves produced from open-pulled straw (OPS) vitrified cytoplasts: work in progress

Cryopreservation of cytoplasts would help to resolve the logistics of matching the availability of oocytes with embryo donors in nuclear transfer. Therefore, the developmental potential of nuclear transfer bovine embryos reconstructed using vitrified cytoplasts was investigated. In vitro matured oocytes were denuded, enucleated, activated with calcium ionophore (10 microM, 5 min) and cycloheximide (10 microg/mL, 6 h) and then vitrified by the open pulled straw (OPS) method. After immediate warming, the nuclear transfer embryos were reconstructed using blastomeres from nonvitrified,in vitro-produced embryo donors. Compared with control nuclear transfer embryos that were reconstructed using nonvitrified cytoplasts, fusion rates (% +/- SEM) were not affected (83.7+/-9.2 vs. 79.8+/-4.6; P>0.05), but cleavage (55.7+/-2.9 vs. 92.8+/-3.9; P = 0.0002) and blastocyst rates (7.2+/-5.0 vs. 32.6+/-7.8; P = 0.0025, vitrified vs. nonvitrified cytoplasts, respectively) per successful fusion were reduced. One nuclear transfer blastocyst reconstructed from a vitrified cytoplast was transferred to a synchronized recipient. After a normal length gestation (265 d), twin calves (21 and 26 kg) were delivered. Microsatellite analysis confirmed that the calves were homozygotic (the embryo split in utero), and were derived from the in vitro-produced embryo donor. The twins were dead at birth, but post-mortem analysis of the calves indicated no abnormalities or infections, suggesting that their death was related to the twin pregnancy and the known fragility of nuclear transfer calves. These data demonstrate that open pulled straw-vitrified cytoplasts are capable of supporting full-term development of nuclear transfer embryos.

Open Pulled Straw (OPS) vitrification: a new way to reduce cryoinjuries of bovine ova and embryos

Although cryopreservation of certain mammalian embryos is now a routine procedure, considerable differences of efficiency exist depending on stage, species and origin (in vivo or in vitro produced). Factors that are suspected to cause most of these differences are the amount of the intracellular lipid droplets and the different microtubular structure leading to chilling injury as well as the volume/surface ratio influencing the penetration of cryoprotectants. A new approach, the Open Pulled Straw (OPS) method, which renders very high cooling and warming rates (over 20,000 degrees C/min) and short contact with concentrated cryoprotective additives (less than 30 sec over -180 degrees C) offers a possibility to circumvent chilling injury and to decrease toxic and osmotic damage. In this paper we report the vitrification by the OPS method of in vitro produced bovine embryos at various stages of development. Embryos cryopreserved from Day 3 to Day 7 (Day 0 = day of fertilization) exhibited development into blastocysts at rates equivalent to those of control embryos; even those cryopreserved on Day 1 or 2 exhibited only somewhat reduced survival. Eighty-one percent of Day 8 hatched blastocysts also survived the procedure. The method was also successfully used for bovine oocytes; of 184 vitrified oocytes, 25% developed into blastocysts after fertilization and culture for 7 days. Pregnancies were achieved following transfer after vitrification at both the oocyte and blastocyst stage. The OPS vitrification offers a new way to solve basic problems of reproductive cryobiology and may have practical impact on animal biotechnology and human assisted reproduction.

Open Pulled Straw (OPS) vitrification: a new way to reduce cryoinjuries of bovine ova and embryos

Although cryopreservation of certain mammalian embryos is now a routine procedure, considerable differences of efficiency exist depending on stage, species and origin (in vivo or in vitro produced). Factors that are suspected to cause most of these differences are the amount of the intracellular lipid droplets and the different microtubular structure leading to chilling injury as well as the volume/surface ratio influencing the penetration of cryoprotectants. A new approach, the Open Pulled Straw (OPS) method, which renders very high cooling and warming rates (over 20,000 degrees C/min) and short contact with concentrated cryoprotective additives (less than 30 sec over -180 degrees C) offers a possibility to circumvent chilling injury and to decrease toxic and osmotic damage. In this paper we report the vitrification by the OPS method of in vitro produced bovine embryos at various stages of development. Embryos cryopreserved from Day 3 to Day 7 (Day 0 = day of fertilization) exhibited development into blastocysts at rates equivalent to those of control embryos; even those cryopreserved on Day 1 or 2 exhibited only somewhat reduced survival. Eighty-one percent of Day 8 hatched blastocysts also survived the procedure. The method was also successfully used for bovine oocytes; of 184 vitrified oocytes, 25% developed into blastocysts after fertilization and culture for 7 days. Pregnancies were achieved following transfer after vitrification at both the oocyte and blastocyst stage. The OPS vitrification offers a new way to solve basic problems of reproductive cryobiology and may have practical impact on animal biotechnology and human assisted reproduction.

Definition of MHC and T cell receptor contacts in the HLA-DR4restricted immunodominant epitope in type II collagen and characterization of collagen-induced arthritis in HLA-DR4 and human CD4 transgenic mice

Rheumatoid arthritis (RA) is an autoimmune disease associated with the HLA-DR4 and DR1 alleles. The target autoantigen(s) in RA is unknown, but type II collagen (CII) is a candidate, and the DR4- and DR1-restricted immunodominant T cell epitope in this protein corresponds to amino acids 261-273 (CII 261-273). We have defined MHC and T cell receptor contacts in CII 261-273 and provide strong evidence that this peptide corresponds to the peptide binding specificity previously found for RA-associated DR molecules. Moreover, we demonstrate that HLA-DR4 and human CD4 transgenic mice homozygous for the I-Abbeta0 mutation are highly susceptible to collagen-induced arthritis and describe the clinical course and histopathological changes in the affected joints.

Caspase-mediated cleavage is not required for the activity of presenilins in amyloidogenesis and NOTCH signaling

The Alzheimer's disease (AD) associated presenilin (PS) proteins are proteolytically processed. One of the processing pathways involves cleavage by caspases. Pharmacological inhibition of caspases is currently being discussed as a treatment for a variety of neurodegenerative diseases, including AD. We therefore inhibited caspase mediated processing of PS-1 and PS-2 in cells transfected with wt and mutant PS by mutagenizing the substrate recognition site or by using specific peptide aldehydes known to block caspases. We found that the inhibition of caspase mediated processing of PS proteins does not decrease its amyloidogenic activity. PS cDNA constructs with mutations in the caspase cleavage site are biologically active in Caenorhabditis elegans such as the wt human PS proteins, demonstrating that caspase-mediated cleavage is not required for the physiological PS function in NOTCH signaling.

Eating pattern and self-esteem in overweight women

Recent studies have shown that the relationship between poor self-esteem and disturbed eating patterns may be more fully understood when the self-esteem concept is divided into an affective domain ('self-liking') and a cognitive domain ('self-competence'). In the present study 38 overweight women between the ages of 21 and 68 participated in an 8-week weight reduction program whereby the Self-Liking and Competence Scale [SLCS] and the Eating Disorder Scale [EDS-5] were used in order to measure self-esteem and eating patterns, respectively. An improvement in the eating patterns corresponded to an improvement in self-liking, but not in self-competence. Statistically significant weight reduction did occur, but on the average, the subjects still remained overweight. As in other studies on normal weight individuals in analogous test situations completing the same instruments, the results point only to a specific relationship between disturbed eating patterns and self-liking. The results suggest that an increased benefit from a weight reduction program could be expected if strategies for improving eating patterns and self-liking are included. This hypothesis warrants further controlled treatment studies.

Alzheimer's disease associated presenilin-1 holoprotein and its 18-20 kDa C-terminal fragment are death substrates for proteases of the caspase family

Mutations in the presenilin (PS) genes are linked to early onset familial Alzheimer's disease (FAD). PS-1 proteins are proteolytically processed by an unknown protease leading to the formation of two stable fragments of approximately 30 and approximately 20 kDa [Thinakaran, G., et al. (1996) Neuron 17, 181-190]. In addition to the conventional fragments, alternative cleavage products were observed as well. Here we characterize an alternative proteolytic pathway of PS-1 which involves proteases of the caspase superfamily. Caspase mediated cleavage occurs between aspartate 345 and serine 346 C-terminal to the conventional cleavage determined previously [Podlisny, M., et al., (1997) Neurobiol. Dis. 3, 325-337]. Full-length PS-1 can serve as a substrate for caspase-like proteases, as demonstrated by the generation of the alternative C-terminal fragment in cells expressing PS-1 containing the Deltaexon 10 deletion which is known to accumulate as a full-length molecule [Thinakaran, G., et al. (1996)]. By inhibition of de novo protein synthesis in untransfected cells we demonstrate that the conventional C-terminal fragment of PS-1 is a substrate for caspase-like proteases as well. Therefore full-length and the conventional C-terminal fragment of PS-1 can serve as potential death substrates. Due to the fact that very little full-length PS-1 is expressed in vivo, the much more abundant C-terminal fragment and not the full-length precursor is the major in vivo substrate for the alternative cleavage of PS-1 by proteases of the caspase superfamily.

Comparison of six sets of PCR primers from two different genomic regions for amplification of GB virus C/hepatitis G virus RNA

Forty-four clinical samples positive for GB virus C (GBV-C)/hepatitis G virus (HGV) were tested with six primer sets, four from the 5' untranslated region (5'-UTR) and two from the NS5a genomic region. Two of the 5'-UTR primer sets, when used in a single-round 60-cycle PCR, detected between 86.4 and 97.7% of the positive samples, while two different sets from the same area, when used in a nested PCR, amplified between 97.7 and 100% of the positive specimens. Both sets from the NS5a region, when used in a single-round PCR, detected 95.5% of the GBV-C/HGV-positive samples. Parallel testing with two PCR sets, one from the 5'-UTR and a second from NS5a, may eliminate false-negative results attributable to the genetic heterogeneity of the virus.

Electrically induced deposition of metal on the human skin

The diagnosis of electrical lesions may be difficult. Forensic material consisting of 24 post-mortem skin samples from 11 fatalities due to electricity was examined with regard to the deposition of iron or copper on the skin. Metal deposition was demonstrated on the epidermis in eight cases. It is concluded that staining for iron and copper may improve the diagnostic sensitivity of electrical lesions.

Multiple sclerosis in the Faroe Islands. 7. Results of a case control questionnaire with multiple controls

Detailed questionnaires were completed in 1978–79 by 23 of the 28 then known resident Faroese multiple sclerosis (MS) patients and 127 controls. These controls were divided into 69 Group A (patient sibs and other relatives), 37 Group B (matched neighbor controls, their spouses and sibs, plus patient's spouse), and 21 Group C (distant matched controls, spouses, relatives living where MS patients never resided and British troops were not encamped during the war). No differences between cases and controls were found for education, occupation, types of residence, bathing, sanitary or drinking facilities, and nature of house construction or heating. Detailed dietary histories, available for half the subjects, revealed no difference, cases versus controls, for four age periods between age 0 and 30 years, and for 16 specified foodstuffs. Animal exposures showed overall no consistent differences by location or type of animal. There was a tendency to greater exposure to British troops during the war for cases versus Groups A and B, but this did not attain statistical significance. Vaccinations for smallpox, tetanus and diphtheria were less common in the MS; no difference was found for other vaccinations. Except for a relative deficit in the cases for rubella and (insignificantly) for measles, mumps and chicken pox, reported illnesses were equally common among all groups. Operations, hospitalizations and injuries did not differentiate the groups, nor did age at menarche for women. Neurologic symptoms were significantly more common in the cases than in the controls.

Presenilins are processed by caspase-type proteases

Presenilin 1 (PS1) and presenilin 2 (PS2) are endoproteolytically processed in vivo and in cell transfectants to yield 27-35-kDa N-terminal and 15-24-kDa C-terminal fragments. We have studied the cleavage of PS1 and PS2 in transiently and stably transfected hamster kidney and mouse and human neuroblastoma cells by immunoblot and pulse-chase experiments. C-terminal fragments were isolated by affinity chromatography and SDS-polyacrylamide gel electrophoresis and sequenced. The processing sites identified in PS1 and PS2 (Asp345/Ser346 and Asp329/Ser330, respectively) are typical for caspase-type proteases. Specific caspase inhibitors and cleavage site mutations confirmed the involvement of caspase(s) in PS1 and PS2 processing in cell transfectants. Fluorescent peptide substrates carrying the PS-identified cleavage sites were hydrolyzed by proteolytic activity from mouse brain. The PS2-derived peptide substrate was also cleaved by recombinant human caspase-3. Additional processing of PS2 by non-caspase-type proteases was also observed.

Ten days of head down tilt: effects of isotonic and hypertonic saline loads in normal man

The initial response to bed rest involves an increase in central blood volume leading to a an enhanced renal excretion of fluid and electrolytes. Within 24 hours of head-down bed rest a new steady state condition occurs with a sustained reduction of plasma volume, extracellular fluid volume, total body water, and body weight. It was the purpose of the present study to elucidate the volume homeostatic mechanisms during head-down bed rest by investigating the endocrine and renal responses to a load of sodium chloride given as either an isotonic or a hypertonic solution.

[Sjögren's syndrome. New diagnostic aspects]

European criteria for classification of Sjögren's syndrome have recently been developed and evaluated. We report the clinical and laboratory findings in 96 patients with primary Sjögren's syndrome who have been classified according to these new criteria. In our patient population the latency from appearance of the first symptom to diagnosis was 11 years. In addition to sicca symptoms in mucous membranes, the dominant symptoms were periodic fatigue (92%), arthralgia (82%), hoarse voice (71%), dry cough (54%) and diarrhoea (51%). Antibodies to the nuclear antigens SSA and SSB were found in respectively 22.2% and 15.6% of the patients. Two out of ten patients with both anti-SSA and anti-SSB antibodies gave birth to a child with heart block.

Emergence of resistant variants of HIV in vivo during monotherapy with the proteinase inhibitor saquinavir

We examined the phenotypic and genotypic properties of virus from the peripheral blood mononuclear cells (PBMC) and plasma of eight HIV-1-infected asymptomatic patients before and during monotherapy with the proteinase inhibitor saquinavir. Susceptibility of primary isolates to drug was assessed in PBMC culture by deriving IC50 and IC90 values. The observed increases in IC50 and IC90 after approximately one year of therapy with a dosage of 600 mg tds suggests the presence of virus resistant to saquinavir in vivo. The magnitude of this altered susceptibility ranged from three-fold to in one case 100-fold. In two patients a greater than eight-fold decrease in susceptibility to saquinavir was observed. Sequencing of the proteinase genes in viral RNA obtained from patient plasma and/or PBMC was carried out by PCR in parallel with sensitivity testing. In each case between nine and 12 clones were analysed. In the two patients from whom virus had greater than eight-fold reduction in susceptibility, a point mutation was observed in the viral proteinase (Leu90--> Met/Ile). Further mutations were observed at residues 36, 71 and 84 in these subjects. In a third patient, in whom an eight-fold increase in HIV IC50 of saquinavir was observed, no mutations were detected in the proteinase; sequencing of proteinase cleavage sites in viral gag-pol revealed no significant mutations. In no patient was a Gly48-->Val mutation observed, although this has been associated with resistance in vitro. The Leu90-->Met mutation was observed in five subjects, but a greater than eight-fold phenotypic change in antiviral susceptibility was seen in only two of these. Hence, in vivo, the Leu90-->Met but not the Gly48-->Val mutation is necessary, but not sufficient, for phenotypic resistance to saquinavir in HIV.

Evaluation of hepatitis C virus envelope proteins expressed in E. coli and insect cells for use as tools for antibody screening

BACKGROUND/METHODS

The two envelope proteins of hepatitis C virus, E1 and E2, were expressed in E. coli and, as secretory proteins, in Sf9 insect cells using recombinant baculoviruses. Co-infection of insect cells with E1 and E2-recombinant baculoviruses was performed, which has been shown to result in formation of E1-E2 dimers. All envelope proteins were purified by Ni2+-NTA chromatography and used for screening of serum samples in a HCV EIA assay. Serum samples of normal blood donors, chronically HCV-infected patients, a mixed titer panel and several seroconversion panels were screened and compared to test results with Cobas Core Anti-HCV EIA.

RESULTS

Screening of the sera of chronically HCV-infected patients (100% positive in Cobas Core Anti-HCV EIA) revealed 10-40% anti-E1 positive sera using different Sf9-expressed, glycosylated proteins and 93% using E. coli-expressed, non-glycosylated E1 protein. When the same sera were tested with different E2 proteins expressed in Sf9 cells and in E. coli, about 70-73% showed anti-E2 reactivity. When the proteins from Sf9 cells co-infected with E1- and E2-recombinant baculoviruses were tested, 70-80% of the same sera showed anti-envelope reactivity.

CONCLUSIONS

Testing of these patient antisera, and those from the well-characterized mixed titer panel BBI-PHV203, showed that recombinant E1 expressed in E. coli and co-expressed E1 and E2 proteins from Sf9 cells could be used as additional tools for anti-HCV antibody screening.

Purification and in vitro-phospholabeling of secretory envelope proteins E1 and E2 of hepatitis C virus expressed in insect cells

The putative envelope glycoproteins of hepatitis C virus (HCV), E1 and E2, were expressed as recombinant, secretory proteins in Sf9 insect cells through infection with recombinant baculoviruses. The influenza virus hemagglutinin signal sequence (HASS) was inserted upstream of the HCV-cDNAs in order to effect secretion. Furthermore, a hexa-histidine tag for purification on a Ni(2+)-nitrilotriacetic acid (Ni(2+)-NTA) column and a protein kinase A (PKA) recognition sequence for in vitro-phospholabeling were fused upstream of the HCV-cDNA. E1- and E2 proteins lacking their carboxy-terminal, hydrophobic sequence were produced by baculovirus-infected insect cells in bioreactors of 23 1. The medium was concentrated and proteins were purified under native conditions on Ni(2+)-NTA columns. Purified proteins could be phospholabeled in vitro using the catalytic subunit of protein kinase. A isolated from bovine heart and gamma-[32P]ATP. Labeled E1 and E2 proteins expressed in insect cells could be immunoprecipitated with sera from HCV-infected patients. Co-expression of these E1 and E2 proteins led to the formation of E1-E2 complexes within the insect cell and to secretion of these complexes into the medium.

Hepatitis C virus core protein: carboxy-terminal boundaries of two processed species suggest cleavage by a signal peptide peptidase

The expression and processing of hepatitis C virus core protein was analyzed. Two protein bands, 21 kDa (P21), corresponding to the full-length core, and 19 kDa (P19), were detected as major products when core protein was expressed in the standard rabbit reticulocyte lysate system or in Sf9 insect cells. Core proteins with amino-terminal hexa-histidine tags were expressed which allowed the purification of the hexa-histidine P19 core with NI(2+)-NTA columns. With the help of mass spectrometry, the molecular weight of hexa-histidine-P19 was analyzed and its carboxy-terminus could be calculated. Fusion proteins of truncated core/core-E1 species fused to mouse dihydrofolate reductase (mDHFR) showed cleavage in the expected region. Cleavage sites could be determined by amino-terminal protein sequencing of the DHFR-fusion partner. Our data show that there are not one but two core products with an apparent molecular weight of about 19 kDa, ending either at amino acid leucine 179 or leucine 182, respectively. These cleavages in the hydrophobic, carboxy-terminal region of HCV core suggest processing by (a) recently proposed eucaryotic signal peptide peptidase(s) (F. Lyko et al. (1995) J. Biol. Chem. 270, 19873-19878). Furthermore, our results demonstrate that cleavage at these sites and the formation of the P19 species does not require previous processing at the signalase site (position 191/192) of the HCV-polyprotein.