The mTOR regulated RNA-binding protein LARP1 requires PABPC1 for guided mRNA interaction

The mammalian target of rapamycin (mTOR) is a critical regulator of cell growth, integrating multiple signalling cues and pathways. Key among the downstream activities of mTOR is the control of the protein synthesis machinery. This is achieved, in part, via the co-ordinated regulation of mRNAs that contain a terminal oligopyrimidine tract (TOP) at their 5'ends, although the mechanisms by which this occurs downstream of mTOR signalling are still unclear. We used RNA-binding protein (RBP) capture to identify changes in the protein-RNA interaction landscape following mTOR inhibition. Upon mTOR inhibition, the binding of LARP1 to a number of mRNAs, including TOP-containing mRNAs, increased. Importantly, non-TOP-containing mRNAs bound by LARP1 are in a translationally-repressed state, even under control conditions. The mRNA interactome of the LARP1-associated protein PABPC1 was found to have a high degree of overlap with that of LARP1 and our data show that PABPC1 is required for the association of LARP1 with its specific mRNA targets. Finally, we demonstrate that mRNAs, including those encoding proteins critical for cell growth and survival, are translationally repressed when bound by both LARP1 and PABPC1.

Current status of gene therapy for rheumatoid arthritis

Despite the high prevalence of the disease, at present little effective pharmacological treatment of rheumatoid arthritis is available. Novel approaches utilising biological agents have resulted in the development of new antiarthritic and antiinflammatory agents, such as tumour necrosis factor-alpha (TNFalpha)-specific antibodies and interleukin-1 receptor antagonist (IL-1ra). Local gene therapy not only allows the pharmaceutical use of these biologicals, but also allows for continuous drug supply, which is necessary for chronic diseases like rheumatoid arthritis. We discuss the basics of rheumatoid arthritis therapy, candidate genes and possible gene transfer methods. A current clinical gene therapy trial is focusing on the IL-1 system using IL-1ra as a transgene. The transfer system, clinical protocol and preliminary results are described. After treatment of 11 patients we feel that gene therapy will offer potential as a new avenue to treat rheumatoid arthritis.

Treatment of Muscle Injuries by Local Administration of Autologous Conditioned Serum: Animal Experiments Using a Muscle Contusion Model

Muscle contusions represent a major part of sports injuries. The suggested treatments are generally sufficient to support muscle healing, but require a relatively long period of time. Given that autologous blood products are safe treatments, we have used a technique which stimulates the release of certain growth factors in the autologous conditioned serum (ACS). Those growth factors are known to improve the proliferative activity of myogenic precursor cells. Mice were subjected to an experimental contusion injury to their gastrocnemius muscle; one group received local injections of ACS at 2 hrs, 24 hrs, and 48 hrs after injury, a control group received saline injections. The histology results showed that satellite cell activation at 30/48 hrs post injury was accelerated and the diameter of the regenerating myofibers was increased compared to the controls within the first week after injury. ELISA results on the ACS have shown that the elevations in FGF-2 (460 %) and TGF-beta1 (82 %) could be partly responsible for the accelerating effects on regeneration due to proliferative and chemotactic properties. We conclude that ACS injection is a promising approach to reduce the time of recovery from muscle injury. In terms of clinical targets, this new approach could be used in the treatment of sports injuries and may also be interesting in postoperative situations.

The production of anti-inflammatory cytokines in whole blood by physico-chemical induction

OBJECTIVE AND DESIGN

Cytokines such as interleukin-1 (IL-1) play an important role in degenerative musculo-skeletal diseases, including osteoarthritis, and a multitude of inflammatory disorders. Agents that inhibit the action of such cytokines have a high therapeutic potential in such diseases. Here we describe a new method for enhancing the production of the interleukin-l receptor antagonist (IL-1Ra) and other anti-inflammatory cytokines in whole blood.

MATERIAL AND METHODS

Human venous blood was incubated in the presence of CrSO(4)-treated glass beads. Serum was recovered and the concentrations of IL-1Ra and other relevant cytokines were measured by ELISA.

RESULTS

The interaction of the glass bead surface with cells in whole blood increased production of IL-1Ra and anti-inflammatory cytokines. Removal of the beads and centrifugation generated a serum preparation enriched in anti-inflammatory cytokines. This preparation is of therapeutic value in treating various inflammatory and degenerative disorders.

CONCLUSIONS

The increased de novo production of anti-inflammatory cytokines by a direct physico-chemical induction of whole blood in the Orthokin system is feasible and offers an alternative, novel approach to treating mild to moderate OA and other orthopaedic conditions such as degenerative spine diseases.

Spontaneous secretion of interleukin 1 receptor antagonist (IL-1ra) by cells isolated from herniated lumbar discal tissue after discectomy

In the study presented, cells of a herniated lumbar disc were cultivated in vitro and analysed for interleukin 1beta (IL-1beta) and interleukin 1 receptor antagonist (IL-1Ra) production. The objective of this study was the detection of IL-1beta and IL-1Ra secreted by herniated lumbar discal cells after discectomy. The involvement of cytokines in the degeneration of intervertebral discs and in the pathophysiology of radiculopathy is established. Antagonizing proteins, e.g. IL-1Ra are thought to have considerable therapeutic potential. In the present study, a 51-year-old male with massive sequestrated lumbar disc herniation at L5/S1 was treated by microsurgical discectomy. Discal cells were isolated, cultures and culture supernatants immunochemically analysed for IL-1beta and IL-1Ra secretion. Spontaneous secretion of IL-1Ra was found. IL-1beta was not detected. Our findings might contradict recent studies on the role of IL-1beta and IL-1Ra. A possible therapeutic role of exogenous IL-1Ra in disc degeneration needs further research.

Urban-rural differences in cancer incidence in The Netherlands 1989-1991

BACKGROUND

Differences in cancer incidence have been observed between urban and rural communities for many decades. These differences have been attributed for the most part to lifestyle aspects. In Western populations, however, differences in lifestyle have diminished. This study addressed the question: For which cancer sites can differences in cancer occurrence still be demonstrated between urban and rural communities in the Netherlands?

METHODS

Cancer incidence data from 1989 to 1991 inclusive, were obtained from the Netherlands Cancer Registry. Age-adjusted, site-specific incidence rates were calculated for five classes of municipalities classified by address density.

RESULTS

With increasing urbanization, slightly higher incidence rates were observed for all cancer sites combined (rate ratio [RR] = 1.08 in males and 1.12 in females). Statistically significant RR of > 1.4 were observed for Kaposi's sarcoma (m), mesothelioma (m), cancer of the liver (m), mouth/pharynx (m + f), oesophagus (f), larynx (f), lung (f), other respiratory organs (f), cervix (f) and Hodgkin's disease (m). Significantly lower incidence rates were found in urban areas for non-melanoma skin (m + f) and lip cancer (m).

CONCLUSIONS

In males, the urban excess of tobacco-related cancer has largely disappeared. However, urban-rural differences in cancer incidence still exist for other cancer sites and for tobacco-related cancer in females. Apparently, differences in the prevalence of lifestyle factors are still large enough to cause variation in cancer incidence.

Quality of life after acoustic neuroma surgery

A questionnaire was sent to 134 patients who had undergone surgery for a unilateral acoustic neuroma between 1980 and 1993, to obtain data on the consequences on their quality of life, physical condition, social life, employment, and use of medical facilities. Distinctions were made between the translabyrinthine-transotic approach, the suboccipital approach, the tumor size, and the number of operations per patient. We found that the patients' reported state of health after surgery was poorer than that in a group of comparable nonoperated patients. Recuperation after an operation took many months and did not always result in full recovery. Surgery had various effects on preoperative symptoms such as hearing loss, tinnitus, vertigo, and facial nerve dysfunction: improvement, no change, or deterioration. Surgery had severe consequences on social life and occupation, but far less effect on income. Almost one third of the patients required postoperative home help, and a proportion were declared unfit to work. The surgical approach, tumor size, and reoperations had a definite influence on the study parameters. After suboccipital surgery, there were more reports of pain, more declarations of incapacity to work, poorer facial nerve function, and more frequent visits to the general practitioner. The translabyrinthine-transotic approach was associated with more severe pain and more complaints of postoperative vertigo. A greater proportion of the patients with larger tumors were declared unfit to work. The general state of health after suboccipital reoperations was better than after the initial operation; there was no reasonable explanation for this. Facial nerve function deteriorated after reoperation(s).

A trinucleotide repeat combination polymorphism in the cardiac alpha myosin heavy chain (MYH6) gene

A polymorphic trinucleotide repeat combination (GAA)m(GAG)n has been demonstrated in the cardiac alpha myosin heavy chain gene (MYH6), which is located on chromosome 14q, and which is sometimes involved in familial hypertrophic cardiomyopathy. Based on length, at least seventeen alleles varying from 31 to 50 repeats have been detected in a sample of 55 unrelated individuals.

A deletion of 1.6 kb proximal to the CGG repeat of the FMR1 gene causes the clinical phenotype of the fragile X syndrome

The vast majority of individuals with the fragile X syndrome show expanded stretches of CGG repeats in the 5' non-coding region of FMR1. This expansion coincides with abnormal methylation patterns in that area resulting in the silencing of the FMR1 gene. Evidence is accumulating that this directly causes the fragile X phenotype. Very few other mutations in FMR1, causing the fragile X phenotype have been reported thus far and all concerned isolated cases. We, however, report a family, in which 11 individuals have a deletion of 1.6 kb proximal to the CGG repeat of the FMR1 gene. Although fragile X chromosomes were not detected, all 4 affected males and 2 of the carrier females show characteristics of the fragile X phenotype. Using RT-PCR we could demonstrate that FMR1 is not expressed in the affected males, strongly suggesting that the FMR1 promoter sequences 5' to the CGG repeat are missing. The deletion patients have approximately 45 CGG repeats in their FMR1 gene, though not interspersed by AGG triplets that are usually present in both normal and expanded repeats. It is hypothesized that prior to the occurrence of the deletion, an expansion of the repeat occurred, and that the deletion removed the 5' part of the CGG repeat containing the AGG triplets. Transmission of the deletion through the family could be traced back to the deceased grandfather of the affected males, which supports the hypothesis that the FMR1 gene product is not required for spermatogenesis. Finally, the data provide additional evidence that the fragile X syndrome is a single gene disorder.

A deletion of 1.6 Kb proximal to the CGG repeat of the FMR1 gene causes fragile X-like psychological features

In this report we present the results of psychological investigations in a family in which 11 individuals, 7 females and 4 males, have a deletion of 1.6 Kb proximal to the CGG repeat of the FMR1. All 4 males with the deletion and 2 of the female carriers show characteristics of the fragile X clinical and behavioural phenotype. The findings in the present family illustrate that the typical characteristics of the fragile X syndrome can be caused by other types of mutations involving the FMR1 than the highly expanded stretches of CGG repeats in the 5' noncoding region of the FMR1 gene, coinciding with abnormal methylation patterns in that area as present in the vast majority of individuals with the fragile X syndrome.

RFLP haplotyping and mutation analysis of the phenylalanine hydroxylase gene in Dutch phenylketonuria families

Restriction fragment length polymorphism haplotyping of mutated and normal phenylalanine hydroxylase (PAH) alleles in 49 Dutch phenylketonuria (PKU) families was performed. All mutant PAH chromosomes identified by haplotyping (n = 98) were screened for eight of the most predominant mutations. Compound heterozygosity was proven in 40 kindreds. Homozygosity was found for the IVS/2nt1 mutation in 5 families, and for the R158Q and IVS10nt546 mutations in one family each. All patients from these families suffer from severe PKU, providing additional proof that these mutations are deleterious for the PAH gene. Genotypical heterogeneity was evident for mutant haplotype 1 (n = 27) carrying the mutations R261Q (n = 12), E280K (n = 4, P281L (n = 1) and unknown (n = 10), and likewise for mutant haplotype 4 (n = 30) carrying the mutations R158Q (n = 13), Y414C (n = 1) and unknown (n = 16). Mutant haplotype 3 (n = 20), in tight association with mutation IVS12nt1, appeared to be in strong linkage disequilibrium (LDE) with its normal counterpart allele (n = 4). Mutant haplotype 6 (n = 4), in tight association with the IVS10nt546 mutation, showed moderate LDE with its counterpart allele (n = 1). The distribution of the mutant PAH haplotypes 1, 3 and 4 among the Dutch PKU population resembles that in other Northern and Western European countries, but it is striking that mutant haplotype 2 and its associated mutation R408W is nearly absent in The Netherlands, in strong contrast to its neighbouring countries.

Partial reconstruction of the lampbrush loop pair Nooses on the Y chromosome of Drosophila hydei

We present the analysis of genomic DNA fragments that were isolated as potential segments of the lampbrush loop pair Nooses on the short arm of the Y chromosome of Drosophila hydei. More than 300 kb of DNA were recovered in BamHI lambda and cosmid clone groups. This DNA is composed of the Y-specific ay1 family of repetitive DNA sequences, and of other repetitive DNA sequences, which at least in part are also located elsewhere in the genome (Y-associated sequences). Two additional classes of DNA fragments were obtained from an EcoRI library. One of them consists of ay1 repeats without apparent interspersion, including a total of more than 300 kb of DNA. The other is composed of tandemly repeated YsI sequences, a Y-specific sequence derived from ay1. This class includes more than 400 kb of DNA, which is also not interspersed by other sequences. Our results show that only the ay1 repeats interspersed by Y-associated DNA sequences can represent parts of the 260 kb transcription unit forming the lampbrush loop, whereas the ay1 and YsI repeats without interspersion form separate and nontranscribed clusters of repetitive DNA.

Can seduction make straight men gay?

The article raises the question of changing sexual preference: Can a man whose past sexual practice has been almost exclusively heterosexual change his practice to homosexual after being seduced by another man? To those who believe that homosexual preference is homosexual orientation, an innate biological predisposition, the answer is a resounding "no." Contrary to this response, the author presents three cases in which the men switch from heterosexual to homosexual relationships (exclusively in two cases) by means of a sexual encounter initiated by another man. The author credits part of the change to the gay liberation movement which rescued homosexual desire from the hidden, forbidden, and shameful. The evidence that these men experienced a genuine change in sexual preference, shows that life-long, exclusive homosexuality, as articulated by gay rhetoric, is more a statement about the culture in which it occurs than the "essence" of homosexuality. The author concludes that putting the question of "What do I like?" before the question of "Who am I?" would allow more sexual freedom for those interested in crossing the line that divides sexual preferences.

Bracteomania, an inflorescence anomaly, is caused by the loss of function of the MADS-box gene squamosa in Antirrhinum majus

Anomalous flowering of the Antirrhinum majus mutant squamosa (squa) is characterized by excessive formation of bracts and the production of relatively few and often malformed or incomplete flowers. To study the function of squamosa in the commitment of an inflorescence lateral meristem to floral development, the gene was cloned and its genomic structure, a well as that of four mutant alleles, was determined. SQUA is a member of a family of transcription factors which contain the MADS-box, a conserved DNA binding domain. In addition, we analysed the temporal and spatial expression pattern of the squa gene. Low transcriptional activity of squa is detectable in bracts and in the leaves immediately below the inflorescence. High squa transcript levels are seen in the inflorescence lateral meristems as soon as they are formed in the axils of bracts. Squa transcriptional activity persists through later stages of floral morphogenesis, with the exception of stamen differentiation. Although necessary for shaping a normal racemose inflorescence, the squa function is not absolutely essential for flower development. We discuss the function of the gene during flowering, its likely functional redundancy and its possible interaction with other genes participating in the genetic control of flower formation in Antirrhinum.

Recovery and identification of DNA sequences harboured in preserved ancient human bones

A new method is presented to extract and identify specific DNA fragments from well preserved human bones, dating from three different time periods. Bone samples were thoroughly freed from surfacial contaminating DNA. Access to the inner bone spongiosum was achieved by removing the covering bone layers of the vertebra or sternum, whereas the patella, tibia and caput of the femur or humerus were cleaved with an iron saw. After the spongiosum was taken out, extraction of nucleic acids from this "sand" like material was performed by heating at 94 degrees C during 20 min in a buffer containing essentially minor concentrations of detergent, chelating and reducing agents. The extracts were used in various Polymerase Chain Reaction (PCR) protocols to amplify different human specific DNA fragments (originating from chromosomes X and 12). From 15 out of 20 bone samples human-specific gene fragments could thus be identified.

Cavernous hemangioma of the internal acoustic canal

A case report of a 39-year-old man suffering from left-sided, progressive hearing loss is presented. As well, the patient noted ipsilateral recurrent facial paralysis. MRI succeeded in confirming the presence of a tumor in the internal acoustic canal 18 months after the first MRI.

[Phenylketonuria as a model system for DNA diagnosis of hereditary disorders]

Phenylketonuria (PKU), due to a defect in phenylalanine hydroxylase (PAH), is presented as a model system for computer-aided DNA diagnosis of genetic diseases. Eight different restriction fragment length polymorphism (RFLP) markers have been localized within the introns of the 90 kb PAH gene (located on chromosome 12). These RFLPs can be combined in 384 different ways and each combination has been defined as a particular haplotype. A special computer program has been developed to calculate the possible haplotype combinations in a PKU core family (index patient and parents), with the goal to derive unambiguously both the PAH and PKU alleles. Taking into account that participation of other members of the family (grandparents or brothers/sisters) is sometimes necessary, haplotyping by itself is sufficient to establish (or exclude) the PKU status of an individual in approximately eight out of ten PKU families.

Effect of organic substrates on biological sulphide oxidation

Neither acetate nor higher fatty acids and glucose have a significant effect on the biotechnological process for sulphide removal at 20 degrees C, in which sulphide is oxidized to sulphur using oxygen. The oxidation of acetate and propionate with oxygen is mainly dependent on the sulphide and oxygen concentrations in the reactor. The occurrence of Thiothrix filaments in sulphide-removing waste-water treatment systems has been investigated using a fixer-film upflow reactor. The influent of this reactor consisted of anaerobically treated paper-mill waste-water, with a sulphide concentration of 140 mg/l. It was found that sulphide loading rate is the decisive parameter as to whether or not Thiothrix will develop in a sulphide-removing reactor.

Distribution of meiotic recombination along nondisjunction chromosomes 21 in Down syndrome determined using cytogenetics and RFLP haplotyping

Ten families (Down syndrome children and their parents) showing evidence of meiotic recombination between intraparental chromosomes transmitted after nondisjunction were studied. Cytogenetic polymorphisms and a cassette of RFLP markers distributed along chromosome 21 were used to analyze these families to localize the regions of meiotic recombination. Results indicated that only one crossover occurred per meiotic division and that nine of ten nondisjunctions appeared to be of maternal origin. In one family the crossover had taken place in the pericentromeric region, proximal to marker D21S13, which is quite exceptional. A chance of meiotic recombination within region 21q21, flanked by marker D21S72 and the amyloid gene, could be demonstrated in seven of the ten families. Most strikingly, this chance significantly decreased distal to q21, with frequencies of 0.3 and 0.1 in regions q22.2 and q22.3-qter, respectively. It is hypothesized that decreased chiasmata formation in the most distal part of chromosome 21q might promote nondisjunction. Furthermore, data from the ten crossovers made it possible to map provisionally two previously undefined markers, D21S24 and D21S82, to regions q21-qter and q22.1-qter, respectively.

Effect of selective chemical modification and CNBr-cleavage at methionine20 in catalytic activity and substrate binding properties of porcine pancreatic phospholipase A2

Porcine pancreatic phospholipase A2 contains 2 methionine (Met) residues located at positions 8 and 20, respectively. Reaction of the enzyme with methyliodide and iodoacetic acid resulted in the selective methylation and carboxymethylation, respectively, of Met20. It was found that porcine pancreatic iso-phospholipase A2, possessing only Met8, was not affected by either modification. Reaction of porcine phospholipase A2 with cyanogen bromide in 0.1 N hydrochloric acid gave rise to cleavage only at Met20. The enhanced reactivity of Met20 compared to that of Met8 is in agreement with the known X-ray structure of phospholipase A2 which shows that Met8 is located in the interior of the protein, while Met20 is at the surface. Both methylation and carboxymethylation of Met20 do not significantly affect catalytic and substrate binding properties of the enzyme. In contrast, the more rigorous cleavage at Met20 by CNBr resulted in the loss of catalytic activity, while substrate and Ca2+ binding was diminished only to a limited extent. Most likely CNBr cleavage at Met20 perturbs the active site despite the fact that the N-terminal fragment Ala1-Hse20 is still bound via the disulfide bridge Cys11-Cys77 to the remainder of the protein. The results obtained strongly suggest that the conformation of the sequences Ala1-Hse20 and/or Asp21-Gly26 are important for the maintenance of the special microenvironment of the active site cleft.

On the origin of recurrent trisomy 21: determination using chromosomal and DNA polymorphisms

A family is described in which two cases of trisomy 21 occurred in, respectively, a newborn infant and a prenatally diagnosed fetus. Using fluorescent chromosomal polymorphisms, it was established that in both cases the extra chromosome resulted from a first meiotic division error in the mother and that the father contributed the same centromeric region to both children. RFLP-associated probes were used to examine the genetic content of the chromosomes. It was noted that the polymorphism patterns of the chromosomes 21 which both children inherited from their parents were identical for three, but not identical for one of the probes studied. This difference must be the result of recombination. This result is discussed in relation to the suggestion that the increased recurrence rate in mothers with a trisomic child could be due to a reduced recombination rate.

The development and characterization of monoclonal antibodies against rat cytomegalovirus induced antigens

In this paper the development of a battery of approximately 70 mouse monoclonal antibodies (McAbs) to RCMV-induced antigens and their characterization is discussed. Their reactivity with the whole scala of ca. 30 virus specific proteins was tested in an enzyme linked immunoassay (ELISA) whereas their ability to detect RCMV-antigens at different locations of in vitro infected cell cultures and at different stages of infection was tested by immunofluorescence. In order to determine to what specific (viral) protein each of these McAbs is directed against we used an immunoprecipitation technique, followed by SDS-PAGE. Furthermore, neutralizing capacity of each McAb was tested, as well as the immunoglobulin class they belong to. In this manner we defined six categories of monoclonal antibodies on the basis of immunofluorescence aspect. The six categories identify most important viral structural proteins.

Molecular cloning and restriction endonuclease mapping of the rat cytomegalovirus genome

Rat cytomegalovirus (RCMV) DNA was cleaved by restriction endonuclease EcoRI into 24 fragments ranging in mol. wt. from 34 X 10(6) to 0.20 X 10(6), of which 18 fragments could be cloned in plasmid pACYC 184. Restriction endonuclease XbaI cleaved the RCMV genome into 28 fragments, ranging in size from 44 X 10(6) to 0.81 X 10(6), of which 24 fragments were cloned in plasmid pSP62-PL. Among the restriction fragments that could not be cloned were two major terminal colinear fragments, EcoRI-A (34 X 10(6)) and XbaI-A (44 X 10(6)). Thus, the complete sets of recombinant plasmids spanned about 70% of the RCMV genome. Our mapping results including determination of the termini of the genome, characterization of double digestion products of restriction fragments and cross-hybridization of 35S-labelled (cloned) EcoRI and XbaI fragments to Southern blots of EcoRI-, XbaI- or BglII-cleaved RCMV DNA, allowed us to construct the EcoRI and XbaI restriction maps of RCMV DNA. Since no cross-hybridization between internal fragments was seen, it is concluded that the RCMV genome consists of a long unique sequence of 224 kilobases without internal inverted repeat sequences, which is similar to the structures of murine and guinea-pig CMV DNA but unlike that of human CMV DNA. In a minor population (approx. 20%) of the RCMV DNA, one terminus was found to be larger by 0.35 X 10(6) mol. wt. The nature of this fragment is unclear at the moment.

Studies on rat cytomegalovirus induced structural and non-structural proteins present at (immediate-)early and late times of infection

Radioactive-labelled virions and nucleocapsids of rat cytomegalovirus (RCMV) were purified from the supernatant and subcellular fractions of infected rat embryo fibroblasts (REF) and analyzed by SDS-polyacrylamide gel electrophoresis. Nuclear nucleocapsids contain one major protein of 138 kD, which is considered to be the basic invariant structural element of RCMV. Enveloped virions consist of 28 protein species, five of which were clearly identified as glycoproteins (58, 64, 76, 112 and 118 kD). Using pulse labelling procedures on RCMV-infected REF cells, after removal of a previously established translation block by cycloheximide, two RCMV-induced immediate-early (IE) protein species (71 and 85 kD) were both detected in the nuclear and cytoplasmic cell fractions. When pulse-labelling was performed for 16 hours in presence of Actinomycin D, only the 85 kD IE protein was detected in the nucleus. The results indicate that the 85 kD IE polypeptide is of importance in early transcriptional events of viral genes. Protein metabolism studies revealed that late in the course of RCMV infection (at 3 days p.i.) protein synthesis has been dramatically changed. Some cellular proteins are greatly suppressed while other cellular proteins are clearly enhanced. Moreover, active synthesis of 8 new cytoplasmic proteins and 9 new nuclear proteins occurs. Most of these proteins were identified as structural constituents of virions.

Road traffic noise annoyance in Amsterdam

3445 persons living in Amsterdam (1507 male and 1938 female), aged 41-43 years, participated in an investigation in which the relationship was studied between the (measured) road traffic noise in front of the houses in which the participants lived, and the (reported) resulting annoyance and sleep disturbance. We found a smaller number of persons with annoyance and sleep disturbance than we had expected as a result of other investigations. Considerable differences in the annoyance experience were found for different categories of noise-sensitivity. Furthermore, a negative appreciation of other environmental noises and of the living environment increased the prevalence of traffic noise annoyance. Noise sensitivity and this appreciation are mutually dependent: noise-sensitive people have a greater risk of being annoyed by other sounds (aeroplanes, neighbours, work) as well, and they have less appreciation of their living environment. Noise-sensitivity appears to be more strongly represented amongst persons with a higher socio-economic status. In favour of the point of view that an important contribution to annoyance is of nonacoustic character, is the finding that both annoyance and sleep disturbance are greater amongst people who keep their windows closed at the exposed side of their home.

Rat cytomegalovirus induces cellular purine and pyrimidine nucleoside kinases in rat embryo fibroblasts and TK- rat-2 cells. Correlations with the antiviral activity of Acyclovir

Rat cytomegalovirus (RCMV) induces a cytosol thymidine kinase (TK) in G0-phase rat embryo fibroblasts (REF), but not in a TK deficient rat cell line (R-2), though virus titers in both cell types reached comparable levels. The results indicate that TK is neither virus-coded nor is required for a productive infection in R-2 cells. A deoxycytidine kinase (dCK) is induced in either growing or RCMV-infected REF and R-2 cells, suggesting that dCK is essential for both host-cell and viral DNA synthesis. A deoxyguanosine kinase (dGK) is detectable in low concentrations in either growing or G0-phase REF and R-2 cells suggesting that this enzyme is cell-cycle independent. In contrast, RCMV induces high persisting levels of dGK, particularly in R-2 cells, indicating that this enzyme is of crucial importance for viral DNA synthesis. By comparison of thermostabilities and electrophoretic mobilities (Rf for TK, dCK and dGK were 0.12; 0.97; and 0.54, respectively) the enzymes were found to be substrate specific but of cellular origin. In contrast to TK and dCK, only dGK is inhibited by Acyclovir (Ki = 320 microM). It is suggested that RCMV inducable dGK is an important enzyme determining the in vitro anti-CMV activity of Acyclovir.

Biology of rat cytomegalovirus infection

Cytomegalovirus infection of Brown Norway rats was studied after intraperitoneal or subcutaneous inoculation of virus. No clinical illness was apparent during the 1st month postinfection (p.i.). Low titers of virus were detected in many organs at day 4 p.i. for the intraperitoneally inoculated animals and at day 11 p.i. for those inoculated subcutaneously. Thereafter, the virus disappeared from all tested organs except the salivary glands, where it appeared on day 11 p.i. and reached high levels by 4 weeks p.i. Histologically, no abnormalities were observed. The virus had an immunosuppressive effect during the 1st week p.i., as indicated by the immune response to sheep red blood cells.

Rat cytomegalovirus: studies on the viral genome and the proteins of virions and nucleocapsids

The nucleocapsids (N-capsids) isolated from the nuclei of rat cytomegalovirus (RCMV)-infected rat embryo fibroblasts (REF) are composed of three major proteins: 142 X 10(3) (142K), 40K and 32K mol. wt. Nucleocapsids isolated from the cytoplasmic fraction (C-capsids) are composed of proteins found in N-capsids and five major and seven minor new protein species. Most of the proteins present in C-capsids are found in the extracellular enveloped virions, although the ratios vary. Proteins that are abundantly present, particularly in virions (mol. wt. 125K, 116K, 87K, 79K, 71K, 68K, 62K, 50K, 43K and 28K), are probably the major constituents of the viral envelope. The DNA recovered from extracellular virions was purified to homogeneity and by equilibrium centrifugation in CsCl one density class of 1.716 (+/- 0.001) g/ml was found. Contour length measurements showed one size class of a linear double-stranded DNA corresponding to an average mol. wt. of 144(+/-9) X 10(6) which is in good agreement with data obtained by restriction endonuclease analysis (REA), which yielded mol. wt. values of 132(+/-9) X 10(6) (HindIII), 138(+/-2) X 10(6) (EcoRI) and 137 X 10(6) (BglII). The REA patterns also revealed the presence of 0.25 M and 0.5 M fragments, which might indicate, in analogy with other cytomegalo- and herpesviruses, the existence of four different configurations of the RCMV genome. The infectivity of RCMV DNA was determined in subconfluent REF monolayers. A cytopathic effect characteristic of RCMV was observed 6 days post-transfection and up to 60 plaques/microgram DNA were obtained. Using DNA-DNA filter hybridization the degree of homology between the genomes of RCMV and murine or human CMV was examined. Under stringent conditions (50% formamide) values of 12(+/-2)% and 3(+/-1)% were found whereas under non-stringent conditions (20% formamide) values of 21(+/-2)% and 6 (+/-1)% were obtained, respectively.

Isolation of a cytomegalovirus-like agent from wild rats

In 8 of 10 wild rats trapped in The Netherlands, an infectious viruslike agent was isolated predominantly from the salivary glands and could be serially passed in laboratory rats. In rat embryo cells a typical cytomegalo-like cytopathic effect was produced. The morphologic and cultural characteristics of the isolated agent were comparable with those of the mouse cytomegalovirus (MCMV). The virus-nucleocapsid had a size of 92 nm and was not ether-resistant. The extracellular nucleocapsids were often enclosed by an outer layer of very variable shape and size. The formation of Fc receptors on cells infected with the rat virus could be demonstrated. The wild rats possessed neutralizing antibodies to the isolated agent. The rat agent grew only in rat embryo fibroblast cells while MCMV grew in rat and mouse embryo cells. The rat agent gave plaques in REF monolayers. Electron microscope studies showed the presence of nucleocapsids in the nucleus.

Immunological studies on pancreatic phospholipase A2. Antigenic characterization of the NH2-terminal region

Rabbit antisera elicited against pure pig, horse, ox, and sheep pancreatic phospholipase A2 revealed considerable immunological differences when tested by double immunodiffusion and microcomplement fixation assays. Snake venom phospholipases did not show any detectable cross-reactions with the pancreatic enzymes. Microcomplement fixation also clearly demonstrated conformational differences between porcine phospholipase A2 and its zymogen. NH2 terminally modified analogs of porcine phospholipase A2 could be clearly distinguished using the same assay. Moreover, strong evidence was obtained that Ala1-Arg6 is a part of an antigenic determinant. Radioimmune assay, using monovalent phospholipase-specific Fab fragments revealed a maximum number of three antigenic sites of phospholipase that can simultaneously be occupied by antibody. The Fab fragments were separated into three fractions, using three immunoadsorbent columns in series. These Fab fractions showed different inhibitory properties toward micellar binding of phospholipase A2. They also exhibited different protective effects against active center modification.

Sarcoplasmic masses. Enzyme histochemistry and autoradiography

A comparative enzyme-histochemical study was made of the sarcoplasmic masses in a muscle biopsy specimen from a patient with myotonic dystrophy and those in the jaw-muscle of the Rana temporaria tadpole. The enzyme-histochemical patterns of the two methods proved to be identical. An autoradiographic study was made of the sarcoplasmic masses in the R temporaria tadpole with DL-thyroxine-2-14C and levomethionine 35S. The radioactivity labeled compounds were found to be stored or incorporated mainly in the myofibrillae, and virtually not at all in the sarcoplasmic masses.