The characterization of micro-organisms by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

A variety of gram-positive and gram-negative intact bacterial cells have been analysed by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and shown to provide fingerprint mass spectra with discrete peaks being observed over the mass range from 3 to 40 kDa. The spectra show both more peaks and peaks at a higher mass/charge ratio than have hitherto been reported for these micro-organisms and would appear to provide a profile of cellular proteinaceous material. The spectra are shown to be reproducible over variable time periods of up to three months and factors affecting reproducibility are discussed. The procedure, which requires minimal sample preparation, yields results in 30-40 minutes and allows visual identification of species- and strain-specific biomarkers for the characterization of the organisms. The importance of accurately defining sample preparation methodologies is central to the ability of the technique to generate reliable and reproducible data.

Excursion-volume relation of the right hemidiaphragm measured by ultrasonography and respiratory airflow measurements

BACKGROUND

Although real time ultrasonography has been used in the last decade to record diaphragmatic motion, the relation between diaphragmatic excursion and different inspired volumes (VT) has not been assessed by ultrasound.

METHODS

Ten normal subjects were studied in the supine posture. Diaphragmatic excursion and VT were assessed simultaneously by M mode ultrasonography and respiratory airflow measurements at different inspired volumes. Ultrasound recordings of the movement of the right hemidiaphragm were carried out in the longitudinal plane subcostally. The transducer was held in a fixed position by a frame, built especially to eliminate any artefactual movement caused by outward motion of the anterior abdominal wall on inspiration.

RESULTS

Mean (SD) maximal diaphragmatic excursion recorded was 6.0 (0.7) cm. Inspired volumes ranged from 15(5%) to 87(10%) of the subjects' inspiratory capacity. A linear relation between diaphragmatic excursion and VT was found in all subjects (r = 0.976-0.995). The regression line had a slope of 1.66 (0.24) cm/l. This slope had no correlation with either the height (r = 0.007) or weight (r = 0.143) of the subjects. In five subjects in whom diaphragmatic excursion could be recorded at volumes near total lung capacity, the relation between diaphragmatic excursion and VT became alinear at very high lung volumes.

CONCLUSIONS

The relation between diaphragmatic excursion and VT was linear between 15(5%) and 87(10%) of inspiratory capacity. Ultrasonography of the diaphragm is a simple technique that could be applied in the clinical investigation of patients with suspected abnormalities of diaphragmatic movement.

Interleukin-1 inhibits sexual behavior in female but not in male rats

The cytokine interleukin-1 (IL-1) is released by a variety of cells in response to infection or injury. IL-1 produces several neuroendocrine and behavioral effects, including a suppression of reproductive functions and goal-directed behaviors. The present study examined the effect of IL-1 on sexual behavior in male and female rats. The following behavioral tests were employed: preference for a sexually appropriate partner, proceptive (soliciting) behavior, the lordosis quotient (sexual receptivity), and mating performance. Peripheral (ip) IL-1 beta, 2 or 10 micrograms/kg, injected 2 h before testing, significantly suppressed proceptive behavior and sexual receptivity in intact, normally cycling females. In ovariectomized rats treated with ovarian hormones, IL-1 beta (2 or 10 micrograms/kg) significantly decreased the preference for a sexually active male partner and suppressed proceptive behavior and sexual receptivity. These effects were evident 2, but not 4 or 6, h after IL-1 beta administration. Intracerebroventricular administration of IL-1 beta (10 ng/rat) also suppressed the preference for a male partner and proceptive behavior in normally cycling females. Similar doses of IL-1 beta had no suppressive effect on any aspect of male sexual behavior, and the highest dose even increased the preference for a receptive female partner. In contrast to the gender-specific effects on sexual behavior, the suppressive effects of IL-1 beta on activity in the open-field test were comparable in male and female rats. The inhibition of female sexual behavior by IL-1 may be adaptive, in that it prevents conception while the animal is sick, thus reducing the risk of spontaneous abortion or abnormal development.

Accumulation of (3H)glycine by cone bipolar neurons in the cat retina

Cone bipolar neurons in the cat retina were studied in serial sections prepared as electron microscope autoradiograms following intravitreal injection of (3H)glycine. The goal was to learn whether the cone bipolar types that accumulate glycine correspond to the types thought on other grounds to be inhibitory. About half of the cone bipolars in a given patch of retina showed specific accumulation of silver grains. The specificity of accumulation was similar to that shown by glycine-accumulating amacrines. All of the cone bipolars arborizing in sublamina b accumulated glycine but none of the cone bipolars arborizing in sublamina a did so. The types of cone bipolars accumulating glycine did not match the types thought to be inhibitory. Cone bipolar types CBb1 and CBb2 both form gap junctions with the glycine-accumulating AII amacrine, thus raising the possibility that glycine might accumulate in these cone bipolars by diffusion from the AII cell or vice versa. Thus it is logically impossible to tell which of these three cells contains a high-affinity uptake mechanism for glycine and consequently which of the three might actually use glycine as a neurotransmitter.

Depression and anxiety in pediatric inflammatory bowel disease and cystic fibrosis

The lifetime and current prevalence of depression and anxiety disorders was determined in 41 children with Crohn's disease, 12 children with ulcerative colitis, and 52 children with cystic fibrosis, using the Kiddie-Schedule for Affective Disorders and Schizophrenia interview. The lifetime prevalence of depression was 29% in Crohn's disease, 21% in ulcerative colitis, and 11.5% in cystic fibrosis. The difference in the prevalence of depression between Crohn's disease and cystic fibrosis was significant (p less than 0.05). The lifetime and current prevalence of dysthymia was significantly greater in ulcerative colitis than Crohn's disease (p less than 0.01) or cystic fibrosis (p less than 0.01). The lifetime prevalence of atypical depression was significantly greater in Crohn's disease than cystic fibrosis (22% versus 5.8%, p less than 0.05) and was also greater in ulcerative colitis than cystic fibrosis (21% versus 5.8%, p = 0.1). There was no difference between the groups in the current prevalence of major depression or atypical depression, or in the lifetime or current prevalence of anxiety disorders.

Posterior capsulectomy in pediatric cataract surgery: the necessity of a choice

OBJECTIVE

The purpose of the study is to evaluate whether a posterior capsulectomy combined with anterior vitrectomy is a necessity in pediatric cataract.

DESIGN

The incidence of posterior capsule opacification, the need for additional surgical interventions, and the influence of a primary posterior capsulectomy after cataract surgery in children were evaluated. The analysis was carried out by studying patients' records retrospectively or after prospective follow-up.

PARTICIPANTS

In 94 eyes (69 aphakic and 25 pseudophakic), the medical records were studied retrospectively. Twenty-eight eyes (18 aphakic and 10 pseudophakic) were observed prospectively during 1 year after surgery. In 20 eyes (6 aphakic and 14 pseudophakic) of 10 patients with bilateral cataract, a prospective comparison between the 2 eyes of the same patient also was carried out.

INTERVENTION

Cataract surgery through the limbus with or without a primary posterior capsulectomy was performed in 114 eyes (43 of these received a posterior chamber intraocular lens [IOL] and 71 remained aphakic). In 28 eyes, the surgery was carried out by way of the pars plana (6 eyes received an anterior chamber IOL and 22 remained aphakic).

MAIN OUTCOME MEASURES

Incidence of posterior capsule opacification, the need for secondary surgical intervention, and visual acuity were measured.

RESULTS

Opacification of the posterior capsule is observed in all children's eyes when a primary posterior capsulectomy (combined with an anterior vitrectomy) was not carried out. Earlier secondary cataract formation is associated with a younger age and with implantation of an IOL. Eyes undergoing a primary opening of the posterior capsule during the initial surgery of children with bilateral cataract achieved, in most cases, a better visual acuity than did their fellow eyes.

CONCLUSION

Although possibly a choice in older children, a primary posterior capsulectomy combined with anterior vitrectomy is a must in younger children and particularly when implantation of an IOL is planned.

Diaphragmatic movement in hemiplegic patients measured by ultrasonography

BACKGROUND

It is known that automatic breathing is controlled by centres in the lower brain stem, whereas volitional breathing is controlled by the cerebral cortical centres. In hemiplegia, lesions above the brain stem result in paralysis of limb muscles. This study was performed to determine whether the diaphragm might also be affected in patients with hemiplegia.

METHODS

Studies were performed in six normal control subjects and in eight patients with complete hemiplegia caused by a lesion above the brain stem, all with no known chest disease. Full lung function tests were performed. Diaphragmatic excursion and inspired volume (VT) were measured simultaneously by M mode ultrasonography and respiratory airflow measurements. Recordings of diaphragmatic excursion were performed on each side separately during volitional and automatic breathing at a similar range of VT.

RESULTS

Lung function tests lay within the normal range in all the control subjects. In the hemiplegic patients mean (SD) vital capacity was 79 (18)% and residual volume was 123(30)% of predicted. Total lung capacity and functional residual capacity were in the normal range. In the control subjects no significant difference in diaphragmatic excursion was found between volitional and automatic breathing for the same range of inspired volume. By contrast, there was a significant decrease in diaphragmatic excursion during volitional breathing compared with automatic breathing on the affected side in four of the eight hemiplegic patients.

CONCLUSIONS

In four of eight hemiplegic patients reduced diaphragmatic movement was present on the paralysed side during volitional inspiration when compared with automatic inspiration. The hemidiaphragm may be involved on the affected side in patients with hemiplegia.

Prevention of soman-induced cognitive deficits by pretreatment with human butyrylcholinesterase in rats

This study examined the ability of pretreatment with human serum butyrylcholinesterase (HuBChE) to prevent soman-induced cognitive impairments. Behavioral testing was carried out using the Morris water maze task evaluating learning, memory, and reversal learning processes. Pretreatment with HuBChE significantly prevented the memory and reversal learning impairments induced by soman. A small deficiency in performance was observed only during part of the learning period in HuBChE-treated rats after administration of soman. Results support the contention that pretreatment alone with HuBChE is sufficient to increase survival and to prevent impairment in cognitive functioning following exposure to soman.

Thrombolytic therapy for acute stroke in late pregnancy with intra-arterial recombinant tissue plasminogen activator

BACKGROUND AND PURPOSE

The most common presentation of ischemic stroke related to pregnancy is arterial occlusion, occurring during the third trimester or postpartum. The authors present the first successful administration of intra-arterial cerebral tissue plasminogen activator to treat an embolic cerebral vascular accident in a 37-week parturient resulting in complete recovery of neurological function.

METHODS

The patient presented with left hemiplegia, left-sided neglect, and aphasia. Right internal carotid artery cerebral angiogram showed occlusion of the mid-M1 segment of the middle cerebral artery (MCA). After 15 mg of tissue plasminogen activator was administered via intra-arterial route, there was greatly improved retrograde flow through the posterior communication artery and the MCA territory.

RESULTS

A reduction in size of the MCA occlusion was noted with improvement of antegrade flow through the MCA. Three days after the procedure, the patient was induced successfully and delivered a healthy infant vaginally.

CONCLUSIONS

This report describes the use of intra-arterial tissue plasminogen activator in the setting of stroke in late pregnancy.

Balloon expulsion test facilitates diagnosis of pelvic floor outlet obstruction due to nonrelaxing puborectalis muscle

We compared balloon expulsion, defecography, colonic transit times, anal manometry, and electromyography in 21 patients with severe constipation. Defecography demonstrated nonrelaxation of the sphincter during straining in all patients. Only 12 patients were unable to expel a balloon. Colonic transit was normal (five) or showed rectosigmoid delay (seven). All 12 patients were offered biofeedback. The nine patients able to expel a balloon had normal colonic transit (six) or colonic inertia (two). Rectosigmoid delay was due to severe intussusception in one patient. Anal manometry and pudendal nerve latencies revealed no difference between those who could and those who could not expel a balloon. Balloon expulsion seems to be a more reliable way to diagnose pelvic floor outlet obstruction due to nonrelaxation of the puborectalis muscle. Nonrelaxation of the sphincter on defecography should be correlated with balloon expulsion and colonic transit studies.

Antiviral properties of palinavir, a potent inhibitor of the human immunodeficiency virus type 1 protease

Palinavir is a potent inhibitor of the human immunodeficiency virus type 1 (HIV-1) and type 2 (HIV-2) proteases. Replication of laboratory strains (HIV-1, HIV-2, and simian immunodeficiency virus) and HIV-1 clinical isolates is inhibited by palinavir with 50% effective concentrations ranging from 0.5 to 30 nM. The average cytotoxic concentration of palinavir (35 microM) in the various target cells indicates a favorable therapeutic index. Potent antiviral activity is retained with increased doses of virus and with clinical isolates resistant to zidovudine (AZT), didanosine (ddI), or nevirapine. Combinations of palinavir with either AZT, ddI, or nevirapine demonstrate synergy or additivity in the inhibition of HIV-1 replication. Palinavir retains anti-HIV-1 activity when administered postinfection until times subsequent to the reverse transcription step. In chronically infected CR-10 cells, palinavir blocks Gag precursor polyprotein processing completely, reducing greater than 99% of infectious particle production. The results indicate that the antiviral activity of palinavir is specific to inhibition of the viral protease and occurs at a late stage in the replicative cycle of HIV-1. On the basis of the potent in vitro activity, low-level cytotoxicity, and other data, palinavir was selected for in-depth preclinical evaluation.

High-risk behaviors for HIV: a comparison between crack-abusing and opioid-abusing African-American women

High rates of unprotected sexual behaviors and the exchange of sex for crack have been reported among female crack cocaine users. This subpopulation of drug users is at significant risk for contracting and transmitting HIV and AIDS. To date, there has been no research comparing crack- and opioid-abusing women, particularly regarding their involvement in high-risk behaviors and other key background indicators for different subgroups of drug-abusing women. Sixty-one crack-abusing African-American women who recently entered an intensive outpatient treatment program were compared to 64 matched women whose primary drug of abuse was heroin. The opioid subgroup represented both those who were involved in methadone maintenance and those who were out of treatment. Higher rates of high-risk sexual behaviors were reported by the crack subgroup, including prostitution, number of sexual partners, and infrequency of condom use. As expected, i.v. drug use and high-risk behaviors associated with needle use were much higher among the opioid subgroup. Other significant differences were found between the two groups across key indicators. Individuals in the crack subgroup were younger, cared for more children, were less employable, were less likely to be married, and had more extensive lifetime substance abuse. Quantitative and qualitative background and clinical data are also presented. The nature of crack versus heroin abuse is also discussed, particularly in relation to high-risk sexual behaviors. Finally, the impact of the findings on developing appropriate treatment interventions for both groups is addressed.

Convergence and divergence of cones onto bipolar cells in the central area of cat retina

In the central area of cat retina the cone bipolar cells that innervate sublamina b of the inner plexiform layer comprise five types, four with narrow dendritic fields and one with a wide dendritic field. This was shown in the preceding paper (Cohen & Sterling 1990 a) by reconstruction from electron micrographs of serial sections. Here we show by further analysis of the same material that the coverage factor (dendritic spread x cell density) is about one for each of the narrow-field types (b1, b2, and b4). The same is probably true for the other narrow-field type (b3), but this could not be proved because its dendrites were too fine to trace. The dendrites of types b1, b2, and b4 collect from all the cone pedicles within their reach and do not bypass local pedicles in favour of more distant ones. The dendrites of type b5, the wide-field cell, bypass many pedicles. On average 5.1 +/- 1.0 pedicles coverage on a b1 bipolar cell; 6.0 +/- 1.2 converge on a b2 cell and 5.7 +/- 1.5 converge on a b4 cell. Divergence within a type is minimal: one pedicle contacts only 1.2 b1 cells, 1.0 b2 cells, and 1.0 b4 cells. Divergence across types is broad: each pedicle apparently contacts all four types of the narrow-field bipolar cells that innervate sublamina b. Each pedicle probably also contacts an additional 4-5 types of narrow-field bipolar cell that innervate sublamina a. There are several possible advantages to encoding the cone signal into multiple, parallel, narrow-field pathways.(ABSTRACT TRUNCATED AT 250 WORDS)

Induced differentiation in HT29, a human colon adenocarcinoma cell line

The human colon adenocarcinoma cell line HT29 displays an undifferentiated phenotype under standard growth conditions. When these cells were cultured for 21 days and then treated with forskolin, most of the cells formed brush borders on their apical surfaces. Brush border formation was inhibited by cytochalasin D but not by colchicine. Colchicine, nocodazole and taxol were found to induce differentiation and apoptosis in HT29 cells. Differentiation was characterized by flattening of the cells, formation of brush borders on apical surfaces and tight junctions between adjacent cells. Apoptosis was characterized by detachment of round cells from the cell layer, condensation of nuclear DNA and annexin V binding to cell surfaces. Treatment with colchicine or forskolin induced the association of E-cadherin to the cytoskeleton fraction of subconfluent HT29 cells. This effect was less prominent in post confluent cells. Our data indicate that microtubule-interfering agents may serve as an important tool in the study of differentiation and apoptosis in intestinal carcinoma.

Oxygenation and hemodynamic changes during one-lung ventilation: effects of CPAP10, PEEP10, and CPAP10/PEEP10

The effects of 10 cm H2O positive end-expiratory pressure (PEEP10), 10 cm H2O continuous positive airway pressure (CPAP10), and their combination (CPAP10/PEEP10) on oxygenation and hemodynamics were studied in 20 patients undergoing one-lung ventilation (OLV) with 50% nitrous oxide, isoflurane, and oxygen. Compared to OLV alone, CPAP10 and CPAP10/PEEP10 significantly increased PaO2 (from 80 +/- 6 to 125 +/- 11 and 137 +/- 17 mmHg, respectively); increased SaO2 (from 93.9 +/- 0.8 to 97.1 +/- 0.5 and 97.0 +/- 0.6%, respectively); and decreased Qs/Qt% (from 36.4 +/- 1.6 to 26.2 +/- 2.0 and 23.2 +/- 2.0%, respectively). Although not statistically significant, PEEP10 caused an increase in PaO2 (to 105 +/- 12 mmHg) and a decrease in Qs/Qt% (to 27.6 +/- 2.1%), which are of clinical significance. However, CPAP10/PEEP10 caused a significant decrease in cardiac output (from 4.50 +/- 0.26 to 3.83 +/- 0.22 L/min), stroke volume (58.6 +/- 3.0 to 52.8 +/- 2.9 mL/beat), and oxygen delivery (653 +/- 39 to 590 +/- 38 mL/min). Application of CPAP10, PEEP10 or their combination had no significant effect on heart rate, arterial, pulmonary arterial, mean pulmonary capillary wedge or central venous pressures, systemic or pulmonary vascular resistances, or mixed venous oxygen saturation. Overall, CPAP10 had the most beneficial effect on oxygenation and hemodynamics during OLV with 50% N2O, isoflurane and oxygen.

Phakic posterior chamber intraocular lens for the correction of anisometropia and treatment of amblyopia

PURPOSE

To assess the potential visual benefits of posterior chamber phakic intraocular lens implants in eyes of children with anisometropic amblyopia.

METHODS

In a prospective study, three girls 9, 14, and 18 years old with high anisometropia and deep amblyopia were included in this study. The phakic posterior chamber intraocular lens (ICL; STAAR Surgical AG, Nidau, Switzerland) was used to correct the anisometropia. This intraocular lens was inserted in the anterior chamber through a 3.0-mm temporal clear cornea incision and manipulated into the posterior chamber using an iris manipulator. A peripheral iridectomy was performed using the Ocutome Probe (Storz; Premiere, St. Louis, Missouri). Local therapy with corticosteroids and antibiotics were prescribed for 2 weeks, and patients were followed regularly for a period of 6 to 9 months.

RESULTS

In the three amblyopic eyes of the three patients, the preoperative best-corrected visual acuity of 6/30, 6/60, and 6/30 improved, to 6/7.5 (20/25), 6/30 (20/100), and 6/15 (20/50), respectively, 6 months after the surgery. Binocular functions with development of fusional abilities and stereopsis were observed in two of these patients after the intraocular lens implantation. In the third patient, the fusional abilities developed only after surgical correction of the exotropia. The intraocular pressure remained within normal limits, and there was no significant change in the corneal endothelial cell count during the period of follow-up. No major intraoperative or postoperative complications were observed, except for a temporary pigment dispersion.

CONCLUSIONS

Implantation of phakic posterior chamber intraocular lenses may be beneficial for the treatment of amblyopia in children with anisometropia. Although additional cases and long-term follow-up observations are necessary, it appears that amblyopia may be overcome by the use of posterior chamber phakic intraocular lens implants, even in eyes of children beyond the age generally considered to be responsive to anti-amblyopic treatment.

Traumatic cataract in children: correction of aphakia by contact lens or intraocular lens

PURPOSE

To compare the postoperative complications, visual outcome, and incidence of strabismus in children suffering from traumatic cataract corrected with contact lens or intraocular lens and to follow up the refractive changes in these eyes for an extended period of time.

METHODS

Forty children, 2 to 13 years old at time of surgery for unilateral traumatic cataract, were followed up for 1.5 to 11 years. Seventeen children were corrected with contact lenses and 23 with intraocular lenses. Thirty-two underwent a primary posterior capsulectomy and anterior vitrectomy.

RESULTS

The mean follow-up after surgery was 7.4 years for the children with contact lenses and 6.2 years for those with intraocular lenses. The incidence of secondary surgical interventions was higher among the children corrected with contact lenses. The eight children (five with contact lenses, three with intraocular lenses) who did not undergo primary posterior capsulectomy had Nd:YAG capsulectomy within 1 year after surgery. Fifteen of the 23 children with intraocular lenses (65.2%) achieved a best-corrected visual acuity of 20/40, and 17 children (73.9%) had a final visual acuity of 20/50, but only five of 17 children with contact lenses (35.3%) achieved this level of visual acuity.

CONCLUSIONS

Correction of unilateral aphakia by intraocular lens in children after traumatic cataracts results in better final visual acuities and binocularity with a smaller incidence of strabismus than when correction is carried out by contact lens. Intraocular lens implantation should be considered the primary aphakic correction in children with traumatic cataract.

Renal effects of molecular targeted therapies in oncology: a review by the Cancer and the Kidney International Network (C-KIN)

A number of cancer therapy agents are cleared by the kidney and may affect renal function, including cytotoxic chemotherapy agents, molecular targeted therapies, analgesics, antibiotics, radiopharmaceuticals and radiation therapy, and bone-targeted therapies. Many of these agents can be nephrotoxic, including targeted cancer therapies. The incidence, severity, and pattern of renal toxicities may vary according to the respective target of the drug. Here, we review the renal effects associated with a selection of currenty approved targeted cancer therapies, directed to vascular endothelial growth factor or VEGF receptor(s) (VEGF/VEGFR), epidermal growth factor receptor (EGFR), human epidermal growth factor receptor2 (HER2), BRAF, anaplastic lymphoma kinase (ALK), programmed cell death protein-1 or its ligand (PD-1/PDL-1), receptor activator of nuclear factor kappa-B ligand (RANKL), and mammalian target of rapamycin (mTOR). The early diagnosis and prompt treatment of these renal alterations are essential in the daily practice where molecular targeted therapies have a definitive role in the armamentarium used in many cancers.

A possible role for squalene in the pathogenesis of acne. II. In vivo study of squalene oxides in skin surface and intra-comedonal lipids of acne patients

Skin surface lipids and lipids from open and closed comedones in acne patients were analysed by thin layer chromatography. The results showed that these lipids were enriched in polar lipids, as compared with the skin surface lipids obtained from controls without acne. In both open and closed comedones, these polar lipids appeared to be derived mainly from the oxidation of squalene, which is in agreement with our previous in vitro results. We suggest that squalene oxidation is the link between comedogenesis and bacterial colonization, and based on this, we propose a hypothesis of the pathogenesis of acne.

Telomeric repeats on small polydisperse circular DNA (spcDNA) and genomic instability

Small polydisperse circular DNA (spcDNA) is a heterogeneous population of extrachromosomal circular molecules present in a large variety of eukaryotic cells. Elevated amounts of total spcDNA are related to endogenous and induced genomic instability in rodent and human cells. We suggested spcDNA as a novel marker for genomic instability, and speculated that spcDNA might serve as a mutator. In this study, we examine the presence of telomeric sequences on spcDNA. We report for the first time the appearance of telomeric repeats in spcDNA molecules (tel-spcDNA) in rodent and human cells. Restriction enzyme analysis indicates that tel-spcDNA molecules harbor mostly, if not exclusively, telomeric repeats. In rodent cells, tel-spcDNA levels are higher in transformed than in normal cells and are enhanced by treatment with carcinogen. Tel-spcDNA is also detected in some human tumors and cell lines, but not in others. We suggest, that its levels in human cells may be primarily related to the amount of the chromosomal telomeric sequences. Tel-spcDNA may serve as a unique mutator, through specific mechanisms related to the telomeric repeats, which distinguish it from the total heterogeneous spcDNA population. It may affect telomere dynamics and genomic instability by clastogenic events, alterations of telomere size and sequestration of telomeric proteins.