Preoperative word-finding difficulties in children with posterior fossa tumours: a European cross-sectional study.

PURPOSE: Posterior fossa tumour surgery in children entails a high risk for severe speech and language impairments, but few studies have investigated the effect of the tumour on language prior to surgery. The current crosslinguistic study addresses this gap. We investigated the prevalence of preoperative word-finding difficulties, examined associations with medical and demographic characteristics, and analysed lexical errors. METHODS: We included 148 children aged 5-17 years with a posterior fossa tumour. Word-finding ability was assessed by means of a picture-naming test, Wordrace, and difficulties in accuracy and speed were identified by cut-off values. A norm-based subanalysis evaluated performance in a Swedish subsample. We compared the demographic and medical characteristics of children with slow, inaccurate, or combined slow and inaccurate word finding to the characteristics of children without word-finding difficulties and conducted a lexical error analysis. RESULTS: Thirty-seven percent (n = 55) presented with slow word finding, 24% (n = 35) with inaccurate word finding, and 16% (n = 23) with both slow and inaccurate word finding. Children with posterior fossa tumours were twice as slow as children in the norming sample. Right-hemisphere and brainstem location posed a higher risk for preoperative word-finding difficulties, relative to left-hemisphere location, and difficulties were more prevalent in boys than in girls. The most frequent errors were lack of response and semantically related sideordinated words. CONCLUSION: Word-finding difficulties are frequent in children with posterior fossa tumours, especially in boys and in children with right-hemisphere and brainstem tumours. Errors resemble those observed in typical development and children with word-finding difficulties.

Predicting career sector intent and the theory of planned behaviour: survey findings from Australian veterinary science students.

BACKGROUND: Producing graduates for a breadth of sectors is a priority for veterinary science programs. Undergraduate career intentions represent de-facto 'outcome' measures of admissions policy and curricula design, as intentions are strong predictors of eventual behaviour. Informed by Ajzen's Theory of Planned Behaviour, this study aimed to identify if contextually relevant attitudes and self-ratings affect student intentions for veterinary career sectors. RESULTS: Survey responses from 844 students enrolled in five Australian veterinary programs in 2014 were analysed. Intention was measured for biomedical research/academia, industry, laboratory animal medicine, public health/government/diagnostic laboratory services, mixed practice, intensive animal production, companion animal practice, not work in the veterinary profession, and business/entrepreneurship. Hierarchical multiple linear regression analysis enabled comparison of explanation of variance in intent by demographics, animal handling experience, species preference, and attitudes to aspects of veterinary work. Career sector intentions were highest for mixed or companion animal clinical practice, then business/entrepreneurship, then non-clinical sectors. Overall, intent was explained to a greater extent by species preferences than by animal experience, attitudes to aspects of veterinary work and demographics (with the exception of mixed practice intent) with gender having no significant effect. Several variables exerted negative effects on career intent for less popular career sectors. CONCLUSION: Ajzen's Theory of Planned Behaviour (TPB) provides a framework to increase understanding of and predict career sector intentions. Incorporation of attitude and self-efficacy measures in our study revealed preference for species types contributes greatly to career sector intentions for veterinary students, particularly for the more popular practice based sectors. Importantly, specific species preferences and other attitudes can have a negative effect on intent for non-aligned veterinary sectors. Further research is required to identify additional attitudes and/or beliefs to better explain variance in intent for less popular career sectors. Veterinary admissions processes may benefit from utilising the TPB framework. Identified effects revealed by this study may stimulate innovation in marketing, recruitment, admissions and curricular design, such as timing and role modelling, to utilise positive effects and mitigate against negative effects identified for sectors requiring greater representation of career intent in the student body.

Discovery of a novel HLA-B*15 allele, HLA-B*15:379, in a patient from Guinea-Bissau.

HLA-B*15:379 differs from HLA-B*15:03:01:01 by a c.T539G substitution in exon 3.

Characterization of a reversible lameness model in the horse.

OBJECTIVE: Characterization of a model of reversible foot lameness in the horse. METHODS: Both forelimb hooves were fitted with a circumferential clamp. After three baseline measurements utilizing a force platform, one clamp was tightened to induce a grade 2.5/5 lameness and left in place for 120 hours. Serial heart rate and force platform measurements were obtained and the asymmetry index was calculated. After 120 hours, the clamp was released and force platform data recorded until the horse returned to soundness. The procedure was repeated for the opposite forelimb. The responses of treatment compared with the control for each outcome were analysed using linear mixed models. Time, limb (left or right), order of treatment, and interaction between time and order were used as fixed effects, whereas horse and limb were used as random effects. RESULTS: There was a significant increase in lameness associated with time and treatment order, where the second limb treated was more lame, based on the force platform data. The heart rate increased significantly with time and was significantly greater while the first limb was being treated. There was a significant effect of time on the increased subjective lameness score. CLINICAL SIGNIFICANCE: The lameness was present throughout the measurement period, though the level of lameness lessened with time. The model may be applicable for evaluation of mechanisms to treat pain in the horse. The reason for the difference in treatment order needs to be identified.

Atmospheric chemistry of C2F5CH2OCH3 (HFE-365mcf).

FTIR smog chamber techniques were used to measure k(Cl + C(2)F(5)CH(2)OCH(3)) = (2.52 ± 0.37) × 10(-11) and k(OH + C(2)F(5)CH(2)OCH(3)) = (5.78 ± 1.02) × 10(-13) cm(3) molecule(-1) s(-1) in 700 Torr of air diluent at 296 ± 1 K. The atmospheric lifetime of C(2)F(5)CH(2)OCH(3) is estimated to be 20 days. Reaction of chlorine atoms with C(2)F(5)CH(2)OCH(3) proceeds 18 ± 2% at the -CH(2)- group and 82 ± 2% at the -CH(3) group. Reaction of OH radicals with C(2)F(5)CH(2)OCH(3) proceeds 44 ± 5% at the -CH(2)- group and 56 ± 5% at the -CH(3) group. The atmospheric fate of C(2)F(5)CH(2)OCH(2)O radicals is reaction with O(2) to give C(2)F(5)CH(2)OCHO. The atmospheric fate of C(2)F(5)CH(O)OCH(3) radicals is C-C bond-cleavage to give C(2)F(5) radicals and CH(3)OCHO (methyl formate). The infrared spectrum was recorded and used to estimate a global warming potential of 6 (100 year time horizon) for C(2)F(5)CH(2)OCH(3).

Stressful life events are associated with a poor in-vitro fertilization (IVF) outcome: a prospective study.

BACKGROUND: There is preliminary evidence to suggest an impact of stress on chances of achieving a pregnancy with in-vitro fertilization (IVF). The majority of the available research has focused on stress related to infertility and going through IVF-treatment, and it is still unclear whether non-fertility-related, naturally occurring stressors may influence IVF pregnancy chances. Our aim was to explore the association between IVF-outcome and negative, i.e. stressful, life-events during the previous 12 months. METHODS: Prior to IVF, 809 women (mean age: 31.2 years) completed the List of Recent Events (LRE) and questionnaires measuring perceived stress and depressive symptoms. RESULTS: Women who became pregnant reported fewer non-fertility-related negative life-events prior to IVF (Mean: 2.5; SD: 2.5) than women who did not obtain a pregnancy (Mean: 3.0; SD: 3.0) (t(465.28) = 2.390, P = 0.017). Logistic regression analyses revealed that the number of negative life-events remained a significant predictor of pregnancy (OR: 0.889; P = 0.02), when controlling for age, total number of life-events, perceived stress within the previous month, depressive symptoms, and relevant medical factors related to the patient or treatment procedure, including duration of infertility, number of oocytes retrieved and infertility etiology. Mediation analyses indicated that the association between negative life events and IVF pregnancy was partly mediated by the number of oocytes harvested during oocyte retrieval. CONCLUSION: A large number of life-events perceived as having a negative impact on quality of life may indicate chronic stress, and the results of our study indicate that stress may reduce the chances of a successful outcome following IVF, possibly through psychobiological mechanisms affecting medical end-points such as oocyte retrieval outcome.

Cognitive processes involved in the evaluation of life satisfaction: implications for well-being.

Extensive research has been conducted on the level and the predictors of well-being in old age, but less is known about the cognitive processes used by the aging individual to evaluate life satisfaction. To investigate the relationship between well-being in the present and in previous decades in life and explore the cognitive processes involved in these evaluations, 203 old participants aged 70-85 years were interviewed and their level of present life satisfaction and depressive symptoms was measured. One year later, depressive symptoms were recorded for a follow-up sample of 65 participants. The results showed that evaluating old age as the best part of life was related to increased well-being. Evaluations of positive periods in life were based on general positive qualities, whereas specific negative events were given as reasons for nominations of negative periods in life. Deviations from this general pattern were related to lower levels of well-being. Use of comparison strategies to evaluate present life satisfaction was frequently reported, and the use of temporal comparisons was predictive of changes in depression over a one-year period. The present study indicates that the cognitive processes used in the evaluation of life satisfaction are related to present and future well-being.

The UL6 gene product forms the portal for entry of DNA into the herpes simplex virus capsid.

During replication of herpes simplex virus type 1 (HSV-1), viral DNA is synthesized in the infected cell nucleus, where DNA-free capsids are also assembled. Genome-length DNA molecules are then cut out of a larger, multigenome concatemer and packaged into capsids. Here we report the results of experiments carried out to test the idea that the HSV-1 UL6 gene product (pUL6) forms the portal through which viral DNA passes as it enters the capsid. Since DNA must enter at a unique site, immunoelectron microscopy experiments were undertaken to determine the location of pUL6. After specific immunogold staining of HSV-1 B capsids, pUL6 was found, by its attached gold label, at one of the 12 capsid vertices. Label was not observed at multiple vertices, at nonvertex sites, or in capsids lacking pUL6. In immunoblot experiments, the pUL6 copy number in purified B capsids was found to be 14.8 +/- 2.6. Biochemical experiments to isolate pUL6 were carried out, beginning with insect cells infected with a recombinant baculovirus expressing the UL6 gene. After purification, pUL6 was found in the form of rings, which were observed in electron micrographs to have outside and inside diameters of 16.4 +/- 1.1 and 5.0 +/- 0.7 nm, respectively, and a height of 19.5 +/- 1.9 nm. The particle weights of individual rings as determined by scanning transmission electron microscopy showed a majority population with a mass corresponding to an oligomeric state of 12. The results are interpreted to support the view that pUL6 forms the DNA entry portal, since it exists at a unique site in the capsid and forms a channel through which DNA can pass. The HSV-1 portal is the first identified in a virus infecting a eukaryote. In its dimensions and oligomeric state, the pUL6 portal resembles the connector or portal complexes employed for DNA encapsidation in double-stranded DNA bacteriophages such as phi29, T4, and P22. This similarity supports the proposed evolutionary relationship between herpesviruses and double-stranded DNA phages and suggests the basic mechanism of DNA packaging is conserved.

In vitro assembly of the herpes simplex virus procapsid: formation of small procapsids at reduced scaffolding protein concentration.

The herpes simplex virus 1 capsid is formed in the infected cell nucleus by way of a spherical, less robust intermediate called the procapsid. Procapsid assembly requires the capsid shell proteins (VP5, VP19C, and VP23) plus the scaffolding protein, pre-VP22a, a major component of the procapsid that is not present in the mature virion. Pre-VP22a is lost as DNA is packaged and the procapsid is transformed into the mature, icosahedral capsid. We have employed a cell-free assembly system to examine the role of the scaffolding protein in procapsid formation. While other reaction components (VP5, VP19C, and VP23) were held constant, the pre-VP22a concentration was varied, and the resulting procapsids were analyzed by electron microscopy and SDS-polyacrylamide gel electrophoresis. The results demonstrated that while standard-sized (T = 16) procapsids with a measured diameter of approximately 100 nm were formed above a threshold pre-VP22a concentration, at lower concentrations procapsids were smaller. The measured diameter was approximately 78 nm and the predicted triangulation number was 9. No procapsids larger than the standard size or smaller than 78-nm procapsids were observed in appreciable numbers at any pre-VP22a concentration tested. SDS-polyacrylamide gel analyses indicated that small procapsids contained a reduced amount of scaffolding protein compared to the standard 100-nm form. The observations indicate that the scaffolding protein concentration affects the structure of nascent procapsids with a minimum amount required for assembly of procapsids with the standard radius of curvature and scaffolding protein content.

Tau phosphorylation at serine 396 and serine 404 by human recombinant tau protein kinase II inhibits tau's ability to promote microtubule assembly.

In Alzheimer's disease, hyperphosphorylated tau is an integral part of the neurofibrillary tangles that form within neuronal cell bodies and fails to promote microtubule assembly. Dysregulation of the brain-specific tau protein kinase II is reported to play an important role in the pathogenesis of Alzheimer's disease (Patrick, G. N., Zukerberg, L., Nikolic, M., De La Monte, S., Dikkes, P., and Tsai, L.-H. (1999) Nature 402, 615-622). We report here that in vitro phosphorylation of human tau by human recombinant tau protein kinase II severely inhibits the ability of tau to promote microtubule assembly as monitored by tubulin polymerization. The ultrastructure of tau-mediated polymerized tubulin was visualized by electron microscopy and compared with phosphorylated tau. Consistent with the observed slower kinetics of tubulin polymerization, phosphorylated tau is compromised in its ability to generate microtubules. Moreover, we show that phosphorylation of microtubule-associated tau results in tau's dissociation from the microtubules and tubulin depolymerization. Mutational studies with human tau indicate that phosphorylation by tau protein kinase II at serine 396 and serine 404 is primarily responsible for the functional loss of tau-mediated tubulin polymerization. These in vitro results suggest a possible role for tau protein kinase II-mediated tau phosphorylation in initiating the destabilization of microtubules.

Lack of latex allergen contamination of solutions withdrawn from vials with natural rubber stoppers.

The effect on latex allergen contamination and microbial growth of a latex-allergy precaution technique for preparing injectable products was studied. The study consisted of three parts: (1) preparation of 20 samples from vials with latex-containing stoppers in accordance with conventional guidelines, (2) preparation of 20 samples in accordance with latex-allergy precaution guidelines, and (3) preparation of 5 latex-free samples and 1 latex-contaminated sample as negative and positive controls, respectively. The conventional method involved swabbing a vial top with an alcohol prep pad, puncturing the dry natural rubber stopper with an 18-gauge needle attached to a latex-free syringe, and withdrawing the contents of the vial into the syringe. The latex-allergy precaution preparation technique was similar, except that the stopper was removed before the vial contents were withdrawn. There was essentially no difference in latex allergen concentrations between the two drug preparation methods. None of the samples prepared with the standard method supported any microbial growth. One sample prepared with the latex-allergy precaution method grew bacteria. Removal of the dry rubber stopper from vials did not yield solutions with less latex allergen than solutions prepared according to conventional guidelines.

Vogel-fulcher dependence of relaxation rates in a nematic monomer and elastomer

Dielectric relaxation spectroscopy is used to study the relaxation processes in a nematic monomer and the corresponding cross-linked polymer nematic liquid crystal (elastomer). In the frequency window 10 mHz to 2 GHz the monomer liquid crystal shows a single relaxation whereas the polymer exhibits three relaxation processes, two of which are quantitatively analyzed. The temperature dependence of relaxation times in both the monomer and polymer follows a Vogel-Fulcher behavior. The relaxation processes are identified with specific molecular motions and activation energies are calculated in a linear approximation for comparison with literature data.

Assembly of the herpes simplex virus procapsid from purified components and identification of small complexes containing the major capsid and scaffolding proteins.

An in vitro system is described for the assembly of herpes simplex virus type 1 (HSV-1) procapsids beginning with three purified components, the major capsid protein (VP5), the triplexes (VP19C plus VP23), and a hybrid scaffolding protein. Each component was purified from insect cells expressing the relevant protein(s) from an appropriate recombinant baculovirus vector. Procapsids formed when the three purified components were mixed and incubated for 1 h at 37 degrees C. Procapsids assembled in this way were found to be similar in morphology and in protein composition to procapsids formed in vitro from cell extracts containing HSV-1 proteins. When scaffolding and triplex proteins were present in excess in the purified system, greater than 80% of the major capsid protein was incorporated into procapsids. Sucrose density gradient ultracentrifugation studies were carried out to examine the oligomeric state of the purified assembly components. These analyses showed that (i) VP5 migrated as a monomer at all of the protein concentrations tested (0.1 to 1 mg/ml), (ii) VP19C and VP23 migrated together as a complex with the same heterotrimeric composition (VP19C1-VP232) as virus triplexes, and (iii) the scaffolding protein migrated as a heterogeneous mixture of oligomers (in the range of monomers to approximately 30-mers) whose composition was strongly influenced by protein concentration. Similar sucrose gradient analyses performed with mixtures of VP5 and the scaffolding protein demonstrated the presence of complexes of the two having molecular weights in the range of 200,000 to 600,000. The complexes were interpreted to contain one or two VP5 molecules and up to six scaffolding protein molecules. The results suggest that procapsid assembly may proceed by addition of the latter complexes to regions of growing procapsid shell. They indicate further that procapsids can be formed in vitro from virus-encoded proteins only without any requirement for cell proteins.

Global elemental maps of the moon: the Lunar Prospector gamma-Ray spectrometer.

Lunar Prospector gamma-ray spectrometer spectra along with counting rate maps of thorium, potassium, and iron delineate large compositional variations over the lunar surface. Thorium and potassium are highly concentrated in and around the nearside western maria and less so in the South Pole-Aitken basin. Counting rate maps of iron gamma-rays show a surface iron distribution that is in general agreement with other measurements from Clementine and the Lunar Prospector neutron detectors.

Assembly of the herpes simplex virus capsid: preformed triplexes bind to the nascent capsid.

The herpes simplex virus type 1 (HSV-1) capsid is a T=16 icosahedral shell that forms in the nuclei of infected cells. Capsid assembly also occurs in vitro in reaction mixtures created from insect cell extracts containing recombinant baculovirus-expressed HSV-1 capsid proteins. During capsid formation, the major capsid protein, VP5, and the scaffolding protein, pre-VP22a, condense to form structures that are extended into procapsids by addition of the triplex proteins, VP19C and VP23. We investigated whether triplex proteins bind to the major capsid-scaffold protein complexes as separate polypeptides or as preformed triplexes. Assembly products from reactions lacking one triplex protein were immunoprecipitated and examined for the presence of the other. The results showed that neither triplex protein bound unless both were present, suggesting that interaction between VP19C and VP23 is required before either protein can participate in the assembly process. Sucrose density gradient analysis was employed to determine the sedimentation coefficients of VP19C, VP23, and VP19C-VP23 complexes. The results showed that the two proteins formed a complex with a sedimentation coefficient of 7.2S, a value that is consistent with formation of a VP19C-VP23(2) heterotrimer. Furthermore, VP23 was observed to have a sedimentation coefficient of 4.9S, suggesting that this protein exists as a dimer in solution. Deletion analysis of VP19C revealed two domains that may be required for attachment of the triplex to major capsid-scaffold protein complexes; none of the deletions disrupted interaction of VP19C with VP23. We propose that preformed triplexes (VP19C-VP23(2) heterotrimers) interact with major capsid-scaffold protein complexes during assembly of the HSV-1 capsid.

The product of the herpes simplex virus type 1 UL25 gene is required for encapsidation but not for cleavage of replicated viral DNA.

The herpes simplex virus type 1 (HSV-1) UL25 gene contains a 580-amino-acid open reading frame that codes for an essential protein. Previous studies have shown that the UL25 gene product is a virion component (M. A. Ali et al., Virology 216:278-283, 1996) involved in virus penetration and capsid assembly (C. Addison et al., Virology 138:246-259, 1984). In this study, we describe the isolation of a UL25 mutant (KUL25NS) that was constructed by insertion of an in-frame stop codon in the UL25 open reading frame and propagated on a complementing cell line. Although the mutant was capable of synthesis of viral DNA, it did not form plaques or produce infectious virus in noncomplementing cells. Antibodies specific for the UL25 protein were used to demonstrate that KUL25NS-infected Vero cells did not express the UL25 protein. Western immunoblotting showed that the UL25 protein was associated with purified, wild-type HSV A, B, and C capsids. Transmission electron microscopy indicated that the nucleus of Vero cells infected with KUL25NS contained large numbers of both A and B capsids but no C capsids. Analysis of infected cells by sucrose gradient sedimentation analysis confirmed that the ratio of A to B capsids was elevated in KUL25NS-infected Vero cells. Following restriction enzyme digestion, specific terminal fragments were observed in DNA isolated from KUL25NS-infected Vero cells, indicating that the UL25 gene was not required for cleavage of replicated viral DNA. The latter result was confirmed by pulsed-field gel electrophoresis (PFGE), which showed the presence of genome-size viral DNA in KUL25NS-infected Vero cells. DNase I treatment prior to PFGE demonstrated that monomeric HSV DNA was not packaged in the absence of the UL25 protein. Our results indicate that the product of the UL25 gene is required for packaging but not cleavage of replicated viral DNA.

Hexon-only binding of VP26 reflects differences between the hexon and penton conformations of VP5, the major capsid protein of herpes simplex virus.

VP26 is a 12-kDa capsid protein of herpes simplex virus 1. Although VP26 is dispensable for assembly, the native capsid (a T=16 icosahedron) contains 900 copies: six on each of the 150 hexons of VP5 (149 kDa) but none on the 12 VP5 pentons at its vertices. We have investigated this interaction by expressing VP26 in Escherichia coli and studying the properties of the purified protein in solution and its binding to capsids. Circular dichroism spectroscopy reveals that the conformation of purified VP26 consists mainly of beta-sheets (approximately 80%), with a small alpha-helical component (approximately 15%). Its state of association was determined by analytical ultracentrifugation to be a reversible monomer-dimer equilibrium, with a dissociation constant of approximately 2 x 10(-5) M. Bacterially expressed VP26 binds to capsids in the normal amount, as determined by quantitative sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Cryoelectron microscopy shows that the protein occupies its usual sites on hexons but does not bind to pentons, even when available in 100-fold molar excess. Quasi-equivalence requires that penton VP5 must differ in conformation from hexon VP5: our data show that in mature capsids, this difference is sufficiently pronounced to abrogate its ability to bind VP26.

Vanadates form insoluble complexes with histones.

Vanadium oxoanions are known to have a variety of physiological effects including insulin-like activity, inhibition of phosphotyrosine phosphatases, as well as direct interactions with a variety of cellular proteins, such as microtubules. In this study, vanadate was found to form insoluble complexes with histones, as well as other positively charged proteins, in a concentration dependent fashion. This interaction occurred over a 0.5-10 mM range which corresponds to the concentration range required for many of vanadate's known physiological effects. Results from precipitation experiments using vanadate solutions with or without the yellow-orange decavanadate indicated that the decamer form is primarily responsible for this precipitation. Vanadate was able to selectively precipitate histones from soluble chromatin as well as from a soluble bacterial protein extract to which a low concentration of histones had been added. Vanadate was also able to effectively precipitate histone from solutions as low as 0.006 mg/mL histone. Thus, the selective precipitation of histones and other positively charged proteins by vanadate can be utilized as a tool for protein purification. In addition, this interaction may provide insight into the mechanisms for the physiological effects of vanadate.

Background corrections for laser-induced-fluorescence measurements of nitric oxide in lean, high-pressure, premixed methane flames.

An experimental technique is presented that both minimizes and accounts for the interference background when laser-induced-fluorescence (LIF) measurements are made of NO in lean, high-pressure, premixed, CH(4)/O(2)/N(2) flames. Measurement interferences such as fluorescence and Raman scattering from secondary species become increasingly important for high-pressure LIF studies. O(2) fluorescence interferences are particularly troublesome in lean premixed flames. An excitation-detection scheme that minimizes the effects of these interferences is identified. A procedure that corrects the resulting LIF signal so as to account for any remaining interference signal is then developed. This correction is found to vary from less than 10% of the overall NO signal at atmospheric pressure to over 40% of the overall signal at 14.6 atm for LIF measurements of NO in a series of worst-case flames (phi = 0.6, dilution ratio 2.2). The correction technique is further demonstrated to be portable over a useful range of flame conditions at each pressure.

Assembly of herpes simplex virus capsids using the human cytomegalovirus scaffold protein: critical role of the C terminus.

An essential step in assembly of herpes simplex virus (HSV) type 1 capsids involves interaction of the major capsid protein (VP5) with the C terminus of the scaffolding protein (encoded by the UL26.5 gene). The final 12 residues of the HSV scaffolding protein contains an A-X-X-F-V/A-X-Q-M-M-X-X-R motif which is conserved between scaffolding proteins found in other alphaherpesviruses but not in members of the beta- or gamma-herpesviruses. Previous studies have shown that the bovine herpesvirus 1 (alphaherpesvirus) UL26.5 homolog will functionally substitute for the HSV UL26.5 gene (E. J. Haanes et al., J. Virol. 69:7375-7379, 1995). The homolog of the UL26.5 gene in the human cytomegalovirus (HCMV) genome is the UL80.5 gene. In these studies, we tested whether the HCMV UL80.5 gene would substitute for the HSV UL26.5 gene in a baculovirus capsid assembly system that we have previously described (D. R. Thomsen et al., J. Virol. 68:2442-2457, 1994). The results demonstrate that (i) no intact capsids were assembled when the full-length or a truncated (missing the C-terminal 65 amino acids) UL80.5 protein was tested; (ii) when the C-terminal 65 amino acids of the UL80.5 protein were replaced with the C-terminal 25 amino acids of the UL26.5 protein, intact capsids were made and direct interaction of the UL80.5 protein with VP5 was detected; (iii) assembly of intact capsids was demonstrated when the sequence of the last 12 amino acids of the UL80.5 protein was changed from RRIFVA ALNKLE to RRIFVAAMMKLE; (iv) self-interaction of the scaffold proteins is mediated by sequences N terminal to the maturation cleavage site; and (v) the UL26.5 and UL80.5 proteins will not coassemble into scaffold structures. The results suggest that the UL26.5 and UL80.5 proteins form a scaffold by self-interaction via sequences in the N termini of the proteins and emphasize the importance of the C terminus for interaction of scaffold with the proteins that form the capsid shell.