Clustered Damage Research Articles

Gibberellin induced shot berry formation in cv. Early Sweet is a direct consequence of high fruit set

The ‘seedless’ table grape industry relies mainly on stenospermocarpic cultivars, in which endosperm abortion results in berries with seed rudiments and low levels of bioactive gibberellin (GA). Application of GA to enhance berry sizing in these cultivars is often accompanied by adverse effects, one of which is increased proportions of very small berries (termed shot berries). Manual removal of these berries, which is essential to improve uniformity and market value, increases production cost and exposes the cluster to damage. Unraveling the physiological causes of shot berry formation is thus of both scientific and practical value. This study focuses on understanding the GA-mediated regulation of shot berry formation in Vitis vinifera cv. Early Sweet, known for a high proportion of shot berries, which severely damage cluster appearance. As GA is known to induce the parthenocarpic fruit set, we first tested the assumption that the parthenocarpic nature of a fruitlet is a primary cause for shot berry development. We then examined the consequence of the flower load on the proportion of shot berries in the cluster. Our data suggests that: (1) contrary to prior assumptions, the parthenocarpic nature of a fruitlet is not the primary cause for shot berry development, demonstrated by the fact that parthenocarpic fruitlets develop into a full-size berries; (2) the proportion of shot berries on a cluster is a function of the initial flower load on the inflorescence, with high initial flower load resulting in greater shot berry percentage in the cluster; (3) GA treatment bypasses the natural regulation of flower load, resulting in high fruitlet density and increased competition among fruitlets; (4) variation of flower load within the cluster influences berry size uniformity to a greater extent than does the variation in number of cluster per vine. The identity of the factors that determine the fate of a given flower on a high-load cluster remains an open question.

Simulation of Proton-Induced DNA Damage Patterns Using an Improved Clustering Algorithm.

Simulations of deoxyribonucleic acid (DNA) molecular damage use the traversal algorithm that has the disadvantages of being time-consuming, slowly converging, and requiring high-performance computer clusters. This work presents an improved version of the algorithm, "density-based spatial clustering of applications with noise" (DBSCAN), using a KD-tree approach to find neighbors of each point for calculating clustered DNA damage. The resulting algorithm considers the spatial distributions for sites of energy deposition and hydroxyl radical attack, yielding the statistical probability of (single and double) DNA strand breaks. This work achieves high accuracy and high speed at calculating clustered DNA damage that has been induced by proton treatment at the molecular level while running on an i7 quad-core CPU. The simulations focus on the indirect effect generated by hydroxyl radical attack on DNA. The obtained results are consistent with those of other published experiments and simulations. Due to the array of chemical processes triggered by proton treatment, it is possible to predict the effects that different track structures of various energy protons produce on eliciting direct and indirect damage of DNA.

Akdeniz ve Güney Doğu Anadolu Bölgelerinde Bağ Alanlarında Zararlı Olan Lepidoptera Türleri

Bağ yetiştiriciliğinde üretimi sınırlandıran en önemli etmenlerin başında salkımlarda zarar yapan zararlılar gelmektedir. Lobesia botrana (Denis & Schiffermüller) (Lepidoptera: Tortricidae) Akdeniz ve Güneydoğu Anadolu Bölgelerinde salkımlarda zarar yapan en önemli tür olarak bilinmektedir. Bu çalışmayla Akdeniz ve Güneydoğu Anadolu Bölgelerinde salkımlardaki zararlı diğer Lepidoptera türleri saptanmıştır. Yapılan örneklemelerde L. botrana, Cryptoblabes gnidiella (Milliere) ve Cadra figulilella (Gregson) (Lepidoptera: Pyralidae) türleri tespit edilmiştir. Akdeniz Bölgesi’nde L. botrana ve C. gnidiella, Güneydoğu Anadolu Bölgesinde ise L. botrana ve C. figulilella türlerine rastlanmıştır. L. botrana bölgede en yaygın tür olup C. gnidiella turunçgil üretim alanlarına yakın bahçelerde, C. figulilella ise daha çok yere dökülmüş veya sık salkımlara sahip çeşitlerin bulunduğu bağ alanlarında saptanmıştır.

Machine Learning Algorithms in Civil Structural Health Monitoring: A Systematic Review

Applications of Machine Learning (ML) algorithms in Structural Health Monitoring (SHM) have become of great interest in recent years owing to their superior ability to detect damage and deficiencies in civil engineering structures. With the advent of the Internet of Things, big data and the colossal and complex backlog of aging civil infrastructure assets, such applications will increase very rapidly. ML can efficiently perform several analyses of clustering, regression and classification of damage in diverse structures, including bridges, buildings, dams, tunnels, wind turbines, etc. In this systematic review, the diverse ML algorithms used in this domain have been classified into two major subfields: vibration-based SHM and image-based SHM. The efficacy of deploying ML algorithms in SHM has been discussed and detailed critical analysis of ML applications in SHM has been provided. Accordingly, practical recommendations have been made and current knowledge gaps and future research needs have been outlined.

Quantifying ecological and economic value of pest control services provided by bats in a vineyard landscape of central Chile

The top-down suppression of pest insects by their natural enemies, such as insectivorous bats, represents an important ecosystem service in agricultural systems. Recognizing the importance of bats to suppress pest populations and further conserve their populations near agricultural systems could reduce damage to crops thereby potentially increasing the monetary gain of farmers. Viticulture represents one of the most extensive and economically important agricultural crops in the Mediterranean biome. While pest consumption by bats has been recently revealed in vineyards, direct evidence of the reduction of grapevine pests by bats in vineyards is lacking, and their benefits to winegrape production remains to be quantified. Using large nocturnal exclosures in vineyards, we examined the top-down effects of aerial insectivorous bats in suppressing insect populations by assessing leaf and grape cluster damage; we also examined the benefit of these natural pest predators by quantifying resulting increases in potential vineyard yield. Grapevine plants excluded from bats had significantly higher leaf herbivory and greater grape cluster damage than control plots. Grape cluster damage was 7% lower on control plots, yielding an average economic benefit of US$188-$248/ha/year due to bat predation. These results provide the first experimental evidence that bats reduce grapevine pest insect infections and thus increase vineyard yield and winegrowers’ income. Therefore, bats should be included in future biodiversity conservation plans in vineyards and be considered within agricultural management strategies based on natural pest suppression.

Parameters of Transition from Deepening Longitudinal to Continuous Lateral Surface Mining Methods to Decrease Environmental Damage in Coal Clusters

The present paper deals with an original way to reduce the environmental damage caused to land and air resources by surface coal mines with external dumping, due to the transition to internal dumping with filling the worked out space of the surface mine with overburden. The basic principle of the proposed idea is the transition from the deepening longitudinal mining method for the development of inclined and steep coal seam strata to lateral ones. This article substantiates the choice of technology for a block-and-layer continuous lateral mining method, including the construction of a first-stage pit, the use of a combined transport and direct dumping technology for moving overburden to an internal dump when mining blocks using draglines. The advantage of the presented technology, along with filling the internal capacity of the surface mine field with overburden, is the possibility of leveling the relief within the boundaries of the pit allotment and the implementation of reclamation as the mining front moves forward, without waiting for the dump to be completely filled in the boundary contours. Attention is also paid to the economic benefits of block-layer technology and the continuous lateral mining method, in the transition to which the overburden transporting costs can be significantly reduced, while the limitations of the proposed method’s implementation concern specific coal deposits that make up a small part of the fields being developed today by surface mining.

Molecular-dynamics-based characterization and comparison of the radiation damage properties of three polytypes of cubic BC3

Boron ($$\mathrm{B}^{10}$$)-based materials such as boron carbide ($$\mathrm{B}_4\mathrm{C}$$) are used in control rods of the nuclear reactors because of their high neutron capture cross section and resistance to thermal and chemical degradation. There is an interest to consider other materials that may serve this purpose. In particular, boron-doped diamonds are prospective candidates as they are known to have excellent mechanical strength. In this work, molecular dynamics (MD) simulations are used to characterize and compare the basic radiation damage properties of boron-doped diamond with the stoichiometric formula $$\mathrm{BC}_3$$. Only cubic structures of $$\mathrm{BC}_3$$ were considered since the experimentally synthesized structure (as per existing literature) was cubic. The basic radiation damage properties compared include threshold displacement energy, primary damage and defect cluster analysis. In addition, the propensity of the material to amorphize under radiation (RIA – radiation-induced amorphization) was also analysed. It was found that the three materials had very similar threshold displacement energies and hence responded to radiation damage in an identical manner. Furthermore, it was seen that none of them were as favourable as the commonly used $$\mathrm{B}_4\mathrm{C}$$, as all of them amorphized at lower doses. Consequently, it is concluded that $$\mathrm{BC}_3$$, while having excellent mechanical properties, may not have good radiation resistance.

An Acoustic Emission-Based Cluster Damage Model for Simulating Triaxial Compression Behaviors of Granite

The establishment of spatial correlation among scattering acoustic emission (AE) signals has great potential applied into a deep analysis of triaxial compression behaviors by the AE monitoring technology. Taking the randomly distributed AE signal could as the cube cluster by an introduction of covering strategy from the percolation theory, the quantitative evaluation of spatial correlation instead of spatial distribution is effectively made. It presents a cluster-based perspective to investigate the triaxial compression behaviors, especially including the dilatancy based on the volumetric strain correlated to the cube cluster evolution. Besides, considering a damage definition by the AE energy count, the cube cluster damage model is successfully established. Then, by implanting the cube cluster termed AE percolation cluster (APC) into the numerical software FLAC3D, the consistency between numerical and experimental results of four descriptors of strength, axial, hoop and volumetric strains excellently proves the reliability of the cluster damage model. In addition, the damaged cluster shows a potential application for quantitative analysis of the shear failure. Furthermore, a percolation analysis of the granite deformation under triaxial compression is made based on the cluster damage model. The effect of pressure-induced percolation transition (PIPT) is verified for the granite and the volume fraction shows a strong linear dependence on the covering length. Moreover, a series of discussion is made to analyze the influence of mechanical parameters on the sensibility of the cluster damage model. Finally, the influence of damage distribution of sub-clusters on the triaxial compression behaviors is quantitatively determined by the comparison between the linear and exponential distributions. The results verify the effectiveness and sensitivity of the cluster damage model in describing triaxial compression behaviors, which provides a new modeling method to extract more valuable information from the correlated AE signals.

Clusters in Pediatric Rheumatic Diseases.

Rheumatic diseases usually have very diverse and complex pathophysiology resulting in different clinical phenotypes. Some certain phenotypes cluster together with a common presentation, course, and outcome. Our primary aim is to review the known disease clusters in certain rheumatological conditions. Cluster analysis has been reported in several rheumatic diseases, Behcet disease being the most common. Five individual clusters together with some clinical associations have been reported in Behcet patients. Certain antibody-phenotype associations and damage clusters have been reported in systemic lupus erythematosus (SLE) patients as well. Although there is no proper cluster analysis, two distinct phenotypes are evident in deficiency of ADA2 (DADA2): those with a polyarteritis nodosa-like vasculopathy and hematological involvement with pure red cell aplasia or bone marrow failure. The variants are claimed to be different regions of this gene for these 2 phenotypes. Lastly, there is a recent paper grouping ANCA-associated vasculitis according to disease phenotype and antibody associations. There are distinct clusters in certain rheumatic diseases which might help us to predict comorbidities, disease course, and treatment response.

Role of Transient Anions in Chemoradiation Therapy: Base Modifications, Cross-Links, and Cluster Damages Induced to Cisplatin-DNA Complexes by 1-20 eV Electrons.

The molecular mechanism of platinum-based drugs in concomitant chemoradiation therapy relies on enhancement of DNA damage in cancer cells, particularly that of detrimental clustered lesions and cross-links induced by the abundant low-energy electrons (LEEs) generated by ionizing radiation. We provide the complete 1-20 eV electron-energy dependence of the yields of all conformational LEE-induced lesions to biological DNA, when it binds to five molecules of the chemotherapeutic drug cisplatin. Recording at 1 eV intervals clearly show that the enhancement of all lesions is particularly intense at the energies of core-excited transient molecular anions (i.e., TMAs at 5, 6, and 10 eV). New TMAs are observed at 14 and 18 eV, only in yield functions of cisplatin-DNA complexes. Enhancements of all lesions by cisplatin are quantified over the 1-20 eV range, where maxima appear at 14 and 18 eV. The most detrimental lesions to cell survival exhibit the highest enhancements by factors of 2-3. Whereas no cluster lesions are induced by electrons of energy <5 eV in DNA, LEEs of any energy cause clustered damages in the complex. These results confirm the current notion that LEEs and TMAs play a dominant role in the molecular mechanism of platinum-drug chemoradiation therapy.

Analysis of Cluster Damages in Network Systems

Changes in the functional characteristics of a multicommodity network with cluster architecture of the logical links depending on damages of edges of its physical topology graph are studied. The concept of a cluster damage is defined as a damage that separates at least one vertex from its sinks. The analysis is carried out on the class of minimum cluster damages. The stability of each cluster of logical links is analyzed with respect to the set of damages when the damage is not directly aimed at the source vertex of the cluster. Estimates of the cluster integrity on the whole and in terms of the undamaged (undivided) links remaining in the cluster are obtained. These estimates provide a basis for bi-criteria ranking of clusters depending on their susceptibility to nonrandom damages of the network. Characteristics of the minimum cluster damages and methods for their comparison are proposed. This approach can be used for a quick analysis of vulnerability of large territorially distributed systems, including telecommunication, communication, and control systems.

Minibeam radiation therapy: A micro‐ and nano‐dosimetry Monte Carlo study

Minibeam radiation therapy (MBRT) is an innovative strategy based on a distinct dose delivery method that is administered using a series of narrow (submillimetric) parallel beams. To shed light on the biological effects of MBRT irradiation, we explored the micro- and nanodosimetric characteristics of three promising MBRT modalities (photon, electron, and proton) using Monte Carlo (MC) calculations. Irradiation with proton (100MeV), electron (300MeV), and photon (effective energy of 69keV) minibeams were simulated using Geant4 MC code and the Geant4-DNA extension, which allows the simulation of energy transfer points with nanometric accuracy. As the target of the simulations, cells containing spherical nuclei with or without a detailed description of the DNA (deoxyribonucleic acid) geometry were placed at different depths in peak and valley regions in a water phantom. The energy deposition and number of events in the cell nuclei were recorded in the microdosimetry study, and the number of DNA breaks and their complexity were determined in the nanodosimetric study, where a multi-scale simulation approach was used for the latter. For DNA damage assessment, an adapted DBSCAN clustering algorithm was used. To compare the photon MBRT (xMBRT), electron MBRT (eMBRT), and proton MBRT (pMBRT) approaches, we considered the treatment of a brain tumor located at a depth of 75mm. Both mean energy deposition at micrometric scale and DNA damage in the "valley" cell nuclei were very low as compared with these parameters in the peak region at all depths for xMBRT and at depths of 0 to 30mm and 0 to 50mm for eMBRT and pMBRT, respectively. Only the charged minibeams were favorable for tumor control by producing similar effects in peak and valley cells after 70mm. At the micrometer scale, the energy deposited per event pointed to a potential advantage of proton beams for tumor control, as more aggressive events could be expected at the end of their tracks. At the nanometer scale, all three MBRT modalities produced direct clustered DNA breaks, although the majority of damage (>93%) was composed of isolated single strand breaks. The pMBRT led to a significant increase in the proportion of clustered single strand breaks and double-strand breaks at the end of its range as compared to the entrance (7% at 75mm vs 3% at 10mm) in contrast to eMBRT and xMBRT. In the latter cases, the proportions of complex breaks remained constant, irrespective of the depth and region (peak or valley). Enhanced normal tissue sparing can be expected with these three MBRT techniques. Among the three modalities, pMBRT offers an additional gain for radioresistant tumors, as it resulted in a higher number of complex DNA damage clusters in the tumor region. These results can aid understanding of the biological mechanisms of MBRT.

Bridge damage: Detection, IFC-based semantic enrichment and visualization

Building Information Modeling (BIM) representations of bridges enriched by inspection data will add tremendous value to future Bridge Management Systems (BMSs). This paper presents an approach for point cloud-based detection of spalling damage, as well as integrating damage components into a BIM via semantic enrichment of an as-built Industry Foundation Classes (IFC) model. An approach for generating the as-built BIM, geometric reconstruction of detected damage point clusters and semantic-enrichment of the corresponding IFC model is presented. Multiview-classification is used and evaluated for the detection of spalling damage features. The semantic enrichment of as-built IFC models is based on injecting classified and reconstructed damage clusters back into the as-built IFC, thus generating an accurate as-is IFC model compliant to the BMS inspection requirements.

Direct observation of damage clustering in irradiated DNA with atomic force microscopy.

Ionizing radiation produces clustered DNA damage that contains two or more lesions in 10–20 bp. It is believed that the complexity of clustered damage (i.e., the number of lesions per damage site) is related to the biological severity of ionizing radiation. However, only simple clustered damage containing two vicinal lesions has been demonstrated experimentally. Here we developed a novel method to analyze the complexity of clustered DNA damage. Plasmid DNA was irradiated with densely and sparsely ionizing Fe-ion beams and X-rays, respectively. Then, the resulting DNA lesions were labeled with biotin/streptavidin and observed with atomic force microscopy. Fe-ion beams produced complex clustered damage containing 2–4 lesions. Furthermore, they generated two or three clustered damage sites in a single plasmid molecule that resulted from the hit of a single track of Fe-ion beams. Conversely, X-rays produced relatively simple clustered damage. The present results provide the first experimental evidence for complex cluster damage.

Intestinal response to dietary manganese depletion in Drosophila.

Manganese is considered essential for animal growth. Manganese ions serve as cofactors to three mitochondrial enzymes: superoxide dismutase (Sod2), arginase and glutamine synthase, and to glycosyltransferases residing in the Golgi. In Drosophila melanogaster, manganese has also been implicated in the formation of ceramide phosphoethanolamine, the insect's sphingomyelin analogue, a structural component of cellular membranes. Manganese overload leads to neurodegeneration and toxicity in both humans and Drosophila. Here, we report specific absorption and accumulation of manganese during the first week of adulthood in flies, which correlates with an increase in Sod2 activity during the same period. To test the requirement of dietary manganese for this accumulation, we generated a Drosophila model of manganese deficiency. Due to the lack of manganese-specific chelators, we used chemically defined media to grow the flies and deplete them of the metal. Dietary manganese depletion reduced Sod2 activity. We then examined gene and protein expression changes in the intestines of manganese depleted flies. We found adaptive responses to the presumed loss of known manganese-dependent enzymatic activities: less glutamine synthase activity (amination of glutamate to glutamine) was compensated by 50% reduction in glutaminase (deamination of glutamine to glutamate); less glycosyltransferase activity, predicted to reduce protein glycosylation, was compensated by 30% reduction in lysosomal mannosidases (protein deglycosylating enzymes); less ceramide phosphoethanolamine synthase activity was compensated by 30% reduction in the Drosophila sphingomyeline phospodiesterase, which could catabolize ceramide phosphoethanolamine in flies. Reduced Sod2 activity, predicted to cause superoxide-dependent iron-sulphur cluster damage, resulted in cellular iron misregulation.

Identifying damage clusters in patients with systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) causes irreversible damage to organ systems. Recently, evidence has been obtained for subphenotypes of SLE. This study aimed to identify damage clusters and compare the associated clinical manifestations, SLE disease activity, mortality, and genetic risk scores (GRS). The study was conducted on the Hanyang BAE lupus cohort. Patients with disease duration <5years were excluded to minimize confounding effects of disease duration. They were grouped into 3 clusters based on the Systemic Lupus International Collaborating Clinics Damage Index using k-means cluster analysis. Among the 1130 analyzed patients, musculoskeletal damage was most prevalent (20.2%), followed by ocular (11.4%), renal (10.5%), and neuropsychiatric damage (10.2%). Three significantly different damage clusters were identified. Patients in cluster 1 (n=824) showed the least damage. Cluster 2 (n=195) was characterized by frequent renal (55.4%) and ocular (58.0%) damage, and cluster 3 (n=111) was dominated by neuropsychiatric (100%) and musculoskeletal damage (35.1%). Cluster 2 had the highest adjusted mean AMS (adjusted mean SLE Disease Activity Index score; mean±SD: 5.4±2.9), while cluster 3 had the highest mortality (14.4%). Weighted GRS did not differ significantly between the clusters. Patients in prevalent renal and ocular damage cluster had the highest AMS scores, while the cluster with frequent neuropsychiatric damage had the highest mortality.

Ionizing Radiation and Complex DNA Damage: From Prediction to Detection Challenges and Biological Significance.

Biological responses to ionizing radiation (IR) have been studied for many years, generally showing the dependence of these responses on the quality of radiation, i.e., the radiation particle type and energy, types of DNA damage, dose and dose rate, type of cells, etc. There is accumulating evidence on the pivotal role of complex (clustered) DNA damage towards the determination of the final biological or even clinical outcome after exposure to IR. In this review, we provide literature evidence about the significant role of damage clustering and advancements that have been made through the years in its detection and prediction using Monte Carlo (MC) simulations. We conclude that in the future, emphasis should be given to a better understanding of the mechanistic links between the induction of complex DNA damage, its processing, and systemic effects at the organism level, like genomic instability and immune responses.

Spatial distribution of damage affects the healing, growth, and morphology of coral.

Many predators and herbivores do not kill their prey, but rather remove or damage tissue. Prey are often able to heal or regenerate this lost tissue. If the prey are modular organisms (e.g., some plants and cnidarians), regeneration is frequently influenced by other modules interconnected to damaged ones. For example, many coral predators remove tissue from colonies consisting of many polyps, and these polyps often share resources with their neighbors. Thus, the distribution of tissue loss on a coral colony could affect the coral's response. I hypothesized that spatially aggregated damage might be slow to heal due to competing demands on nearby polyps. To explore the spatial patterns of corallivory and their implications, I conducted: (1) field surveys documenting the spatial distribution of lesions on corals; (2) field experiments testing the effect of the distance between lesions on coral tissue healing, skeletal growth, and morphology; and (3) field surveys relating corallivore presence to coral growth and morphology. In the field surveys, lesions were aggregated at multiple spatial scales, and most lesions had other lesions within 2cm. When lesions were near one another, coral tissue regeneration was depressed, although there was no effect on whole colony growth. After a year, however, linear extension was lower in the neighborhood of the lesions. Additionally, gastropod corallivores (Coralliophila violacea) with low movement decreased coral growth and increased coral topographical complexity. These results suggest that corallivores that create clusters of coral damage have a greater effect on coral growth and recovery from damage than corallivores that spread damage throughout the colony.

Radiation Track Structure: How the Spatial Distribution of Energy Deposition Drives Biological Response

Ionising radiation is incredibly effective at causing biological effects. This is due to the unique way energy is deposited along highly structured tracks of ionisation and excitation events, which results in correlation with sites of DNA damage from the nanometre to the micrometre scale. Correlation of these events along the track on the nanometre scale results in clustered damage, which not only results in the formation of DNA double-strand breaks (DSB), but also more difficult to repair complex DSB, which include additional damage within a few base pairs. The track structure varies significantly with radiation quality and the increase in relative biological effectiveness observed with increasing linear energy transfer in part corresponds to an increase in the probability and complexity of clustered DNA damage produced. Likewise, correlation over larger scales, associated with packing of DNA and associated chromosomes within the cell nucleus, can also have a major impact on the biological response. The proximity of the correlated damage along the track increases the probability of miss-repair through pairwise interactions resulting in an increase in probability and complexity of DNA fragments/deletions, mutations and chromosomal rearrangements. Understanding the mechanisms underlying the biological effectiveness of ionising radiation can provide an important insight into ways of increasing the efficacy of radiotherapy, as well as the risks associated with exposure. This requires a multi-scale approach for modelling, not only considering the physics of the track structure from the millimetre scale down to the nanometre scale, but also the structural packing of the DNA within the nucleus, the resulting chemistry in the context of the highly reactive environment of the nucleus, together with the subsequent biological response.

Isolation of the Human Cytomegalovirus from bodily fluids

In vitro studies on the pathogenesis of the human cytomegalovirus (HCMV) are conducted regularly using laboratory adapted strains that lose some characteristics during the adaptation process. Since HCMV is excreted from bodily fluids during infection or reactivation, this work aimed to isolate and culture HCMV from the MRC-5 human cells found in the urine, bronchoalveolar lavage, saliva, and plasma samples of pediatric patients with probable or confirmed infection. The samples were inoculated on cell cultures either for 14 days or until a cytopathic effect (CPE) of 80 % was observed. The cell lysates and supernatants were used to perform successive viral passages. Besides HCMV, the herpes simplex virus was detected from all the saliva samples. Inoculation of the HCMV positive sera induced cell clustering and immediate monolayer damage that restricted their use. One sample of bronchoalveolar lavage induced a CPE after inoculation like that of the HCMV reference strains (Towne and Merlin), which was consequently propagated and titrated. A second viral isolate derived from the urine sample of a patient with congenital infection did not demonstrate a CPE, although presence of the virus had been confirmed using PCR. The viral isolates were examined and found to be negative for adenoviruses or enteroviruses. Despite the evident difficulty encountered for the isolation and harvesting of the HCMV, this work shows that it was possible to obtain a low passage viral strain using a modified shell vial method and inoculation protocol with extended follow-up and confirmation.