Ring 13 in an adult male with a 13:13 translocation mother

A male with a ring 13 chromosome [r(13)(p11q34)], mild mental retardation, short stature, oligoasthenospermia, and few dysmorphisms is reported. His mother who had a poor reproductive history is carrier of a t(13q13q), featuring a dicentric NOR-negative element. The clinical significance of the r(13) and the mother's unusual karyotype are discussed.     

Evaluation of argon laser surgery in children under 13 years of age

Argon laser surgery is an effective treatment for ectasias and congenital port-wine stains; however, its use in children under the age of 13 is controversial. This paper reviews 202 children under the age of 13 who underwent argon laser treatments for congenital port-wine stains, spider angiomas, epidermal nevi, and lentigines. The clinical characteristics of port-wine stains in 170 children are discussed. Good to excellent results (moderate to complete clearing) in port-wine stains were obtained in 60 percent of patients and seemed to correlate best with lack of blanchability on pressure. Hypertrophic scarring was seen in only 7 children, all of whom had undressed wounds; no significant scarring has been seen in any subsequent child who had maintained a dressed wound postoperatively.     

Giemsa banding in the t(13q13q) carrier mother of a translocation trisomy 13 abortus

Summary The abortus of a woman who had had three miscarriages and no normal pregnancies had a 46,XX,D-,t(DqDq)+karyotype. The mother was shown to carry the translocation in balanced state; Giemsa banding demonstrated the abnormal chromosome to be t(13q13q)

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Zusammenfassung Die Abortfrucht einer Frau mit 3 Fehlgeburten und keiner normal ausgetragenen Schwangerschaft hat einen Karyotyp 46,XX,D-,t(DqDq)+.Die Mutter hat die gleiche Translokation im balancierten Zustand. Mit Hilfe der Giemsafärbung erwies sich das abnorme Chromosom als t(13q13q).

     

ATG13

During the past 20 years, autophagy signaling has entered the main stage of the cell biological theater. Autophagy represents an intracellular degradation process that is involved in both the bulk recycling of cytoplasmic components and the selective removal of organelles, protein aggregates, or intracellular pathogens. The understanding of autophagy has been greatly facilitated by the characterization of the molecular machinery governing this process. In yeast, initiation of autophagy is controlled by the Atg1 kinase complex, which is composed of the Ser/Thr kinase Atg1, the adaptor protein Atg13, and the ternary complex of Atg17-Atg31-Atg29. In vertebrates, the orthologous ULK1 kinase complex contains the Ser/Thr kinase ULK1 and the accessory proteins ATG13, RB1CC1, and ATG101. Among these components, Atg1/ULK1 have gained major attention in the past, i.e., for the identification of upstream regulatory kinases, the characterization of downstream substrates controlling the autophagic flux, or as a druggable target for the modulation of autophagy. However, accumulating data indicate that the function of Atg13/ATG13 has been likely underestimated so far. In addition to ensuring proper Atg1/ULK1 recruitment and activity, this adaptor molecule has been implicated in ULK1-independent autophagy processes. Furthermore, recent data have identified additional binding partners of Atg13/ATG13 besides the components of the Atg1/ULK1 complex, e.g., Atg8 family proteins or acidic phospholipids. Therefore, in this review we will center the spotlight on Atg13/ATG13 and summarize the role that Atg13/ATG13 assumes in the autophagy stage play.     

P-13CERVICAL SMEAR REPORTING IN NORTHERN IRELAND SLE PATIENTS

Introduction:  SLE is an autoimmune disease with the potential for multi-organ involvement. It has been suggested that SLE patients may be at increased risk of cervical dysplasia. We studied a cohort of Northern Ireland Lupus patients and compared them to controls within the same geographical location assessing their cervical smear histories and performing an up-to-date cervical smear.
Methods:  A total of 141 SLE patients fulfilling the ACR criteria for lupus were enrolled into the study. They were compared to 138 control patients who were due to attend for a routine cervical smear within the same geographical location. Each patient gave written consent to be involved in the study including access to medical records and pathology data.
Results:   

     

Tannic acid-stained microtubules with 12, 13, and 15 protofilaments

Subunit structure in the walls of sectioned microtubules was first noted by Ledbetter and Porter (6), who clearly showed that certain microtubules of plant meristematic cells have 13 wall protofilaments when seen in cross section. Earlier, protofilaments of microtubular elements had been described in negatively stained material, although exact counts of their number were difficult to obtain. In microtubular elements of axonemes, some success has been achieved in visualizing protofilaments in conventionally fixed and sectioned material (8, 10); much less success has been achieved in identifying and counting protofilaments of singlet cytoplasmic microtubules. By using glutaraldehyde-tannic acid fixation, as described by Misuhira and Futaesaku (7), Tilney et al. (12) studied microtubules from a number of sources and found that all have 13 protofilaments comprising their walls. These authors note that "...the number of subunits and their arrangement as protofilaments appear universal...". Preliminary studies of ventral nerve cord of crayfish fixed in glutaraldehyde-tannic acid indicated that axonal microtubules in this material possess only 12 protofilaments (4). On the basis of this observation, tannic acid preparations of several other neuronal and non-neuronal systems were examined. Protofilaments in microtubules from these several cell types are clearly demonstrated, and counts have been made which show that some kinds of microtubules have more or fewer protofilaments than the usual 13 and that at least one kind of microtubule has an even rather than an odd number.     

Genome sequence of Peptoniphilus rhinitidis 1-13T, an anaerobic coccus strain isolated from clinical specimens

A new Peptoniphilus species has been isolated from samples from a patient who was scheduled for endoscopic sinus surgery for chronic rhinosinusitis. The isolate, Peptoniphilus rhinitidis 1-13(T) (KCTC 5985(T)), can use peptone as a sole carbon source and produce butyrate as a metabolic end product. This is the first report of the draft genome sequence of a novel species in the genus Peptoniphilus within the group of Gram-positive anaerobic cocci.     

Side chain dynamics monitored by 13C-13C cross-relaxation

A method to measure (13)C-(13)C cross-relaxation rates in a fully (13)C labeled protein has been developed that can give information about the mobility of side chains in proteins. The method makes use of the (H)CCH-NOESY pulse sequence and includes a suppression scheme for zero-quantum (ZQ) coherences that allows the extraction of initial rates from NOE buildup curves.The method has been used to measure (13)C-(13)C cross-relaxation rates in the 269-residue serine-protease PB92. We focused on C(alpha)-C(beta) cross-relaxation rates, which could be extracted for 64% of all residues, discarding serine residues because of imperfect ZQ suppression, and methyl (13)C-(13)C cross-relaxation rates, which could be extracted for 47% of the methyl containing C-C pairs. The C(alpha)-C(beta) cross-relaxation rates are on average larger in secondary structure elements as compared to loop regions, in agreement with the expected higher rigidity in these elements. The cross-relaxation rates for methyl containing C-C pairs show a general decrease of rates further into the side chain, indicating more flexibility with increasing separation from the main chain. In the case of leucine residues also long-range C(beta)-C(delta) cross-peaks are observed. Surprisingly, for most of the leucines a cross-peak with only one of the methyl C(delta) carbons is observed, which correlates well with the chi(2) torsion-angle and can be explained by a difference in mobility for the two methyl groups due to an anisotropic side chain motion.     

Chromosomal mapping of human cytokeratin 13 gene (KRT13).

In the present study the human cytokeratin 13 gene (KRT13), encoding a polypeptide characteristic of internal stratified epithelia, has been mapped with the help of the polymerase chain reaction and somatic cell hybrids to chromosome 17. In situ hybridization of a KRT13 cDNA probe to metaphase chromosomes allowed the assignment of the KRT13 gene within the q12-q21.2 region of chromosome 17.     

FRA2B is distinct from inverted telomere repeat arrays at 2q13

Human chromosome 2 was formed by a telomere-to-telomere fusion of two ancestral ape chromosomes. The fusion point is localized in chromosomal band 2q13, which also contains the rare, folate-sensitive fragile site FRA2B. It has been hypothesized that this fragile site may be related to the presence of interstitial telomeric and subtelomeric sequences, which have come to lie in an inverted repeat arrangement as a result of the fusion event. Fluorescence in situ hybridization of a genomic cosmid c8.1, which spans the fusion point, was carried out on metaphase spreads of an individual who expressed the fragile site at 2q13. We show that the fusion point maps distal to this fragile site. Therefore, we conclude that the inverted arrays of telomeric and subtelomeric sequences found at this fusion point are unlikely to correspond to the rare fragile site at 2q13.     

Proteolytic preparation from the culture of Bacillus polymyxa str. 13-13]

A proteolytic preparation has been isolated from the culture fluid filtrate Bacillus polymyxa str. 13-13 by salting out with (NH4)2SO4 (0.7 of complete saturation). The data characterizing the amino acid composition and the enzymic system of the resultant preparation are given. It has been shown that the proteolytic activity depends on the enzyme containing metal ion, i. e. metal enzyme.     

Evaluation of model refinement in CASP13

Performance in the model refinement category of the 13th round of Critical Assessment of Structure Prediction (CASP13) is assessed, showing that some groups consistently improve most starting models whereas the majority of participants continue to degrade the starting model on average. Using the ranking formula developed for CASP12, it is shown that only 7 of 32 groups perform better than a “naïve predictor” who just submits the starting model. Common features in their approaches include a dependence on physics-based force fields to judge alternative conformations and the use of molecular dynamics to relax models to local minima, usually with some restraints to prevent excessively large movements. In addition to the traditional CASP metrics that focus largely on the quality of the overall fold, alternative metrics are evaluated, including comparisons of the main-chain and side-chain torsion angles, and the utility of the models for solving crystal structures by the molecular replacement method. It is proposed that the introduction of these metrics, as well as consideration of the accuracy of coordinate error estimates, would improve the discrimination between good and very good models.     

Quantitative target proteomics of chromosome 13 human blood plasma proteins

Quantitative proteomic analysis of 50 blood plasma samples of healthy volunteers who underwent a comprehensive medical examination and were found eligible for space flights was performed. As a result of directed mass spectrometric analysis, signals for 128 proteins, which accounted for nearly 40% of the total number of chromosome 13 gene products, were detected. The analysis of interindividual variation of concentrations of chromosome 13 proteins showed the presence of a pool comprising 41 proteins with a low variation (CV < 30%), which can potentially be used as biomarkers.     

The Role of the Carbohydrate Recognition Domain of Placental Protein 13 (PP13) in Pregnancy Evaluated with Recombinant PP13 and the DelT221 PP13 Variant

Introduction

Placental protein 13 (PP13), a placenta specific protein, is reduced in the first trimester of pregnancy in women who subsequently develop preeclampsia. A naturally occurring PP13 deletion of thymidine at position 221 (DelT₂₂₁ or truncated variant) is associated with increased frequency of severe preeclampsia. In this study we compared the full length (wildtype) PP13 and the truncated variant.

Methods

Full length PP13 or its DelT₂₂₁ variant were cloned, expressed and purified from E-Coli. Both variants were administrated into pregnant rats at day 8 of pregnancy for slow release (>5 days) through osmotic pumps and rat blood pressure was measured. Animals were sacrificed at day 15 or day 21 and their utero-placental vasculature was examined.

Results

The DelT₂₂₁ variant (11 kDA) lacked exon 4 and a part of exon 3, and is short of 2 amino acids involved in the carbohydrate (CRD) binding of the wildtype (18 kDA). Unlike the wildtype PP13, purification of DelT₂₂₁ variant required special refolding. PP13 specific poly- clonal antibodies recognized both PP13 and DelT₂₂₁ but PP13 specific monoclonal antibodies recognized only the wildtype, indicating the loss of major epitopes. Wildtype PP13 mRNA and its respective proteins were both lower in PE patients compared to normal pregnancies. The DelT₂₂₁ mutant was not found in a large Caucasian cohort. Pregnant rats exposed to wildtype or DelT₂₂₁ PP13 variants had significantly lower blood pressure compared to control. The wildtype but not the DelT₂₂₁ mutant caused extensive vein expansion.

Conclusion

This study revealed the importance of PP13 in regulating blood pressure and expanding the utero-placental vasculature in pregnant rats. PP13 mutant lacking amino acids of the PP13 CRD domain fails to cause vein expansion but did reduce blood pressure. The study provides a basis for replenishing patients at risk for preeclampsia by the full length but not the truncated PP13.     

PKC defends crown against Munc13

Protein kinase C has long been thought to mediate DAG signaling at the synapse. Recently PKC has been supplanted by members of the Unc13 family as the predominant effectors of DAG signaling. Thanks to a study by Wierda and colleagues in this issue of Neuron, PKC returns to reclaim part of the kingdom: both pathways must be active to activate presynaptic potentiation.     

Synthesis and application of 13C enriched phenylisothiocyanate as a 13C NMR protein probe

Phenylisothiocyanate, enriched with 13C at the isothiocyanate carbon, has been synthesized and utilized as a 13C NMR probe of proteins for the first time. The reagent has been used to label the amino groups of oxidized glutathione, and the resulting 13C NMR spectrum shows a prominent thiocarbonyl peak after a single NMR scan. The reagent is also capable of differentiating amino groups on the insulin molecule with distinct peaks corresponding to the amino groups on the A and B chains of insulin. This study illustrates the potential of using a new 13C label to functionalize amino groups of proteins and to study the labeled proteins with 13C NMR.     

13 RNA fitness landscapes

The origin of life is believed to have progressed through an RNA World, in which RNA acted as both genetic material and functional molecules. Understanding early evolution requires systematic knowledge of the relationship between RNA sequence and functional activity. In particular, knowing the structure of the fitness landscape of RNA is critical in estimating the probability of the emergence of functional sequences and the role of historical accident during evolution. Much theoretical work has been devoted to fitness landscapes, but experimental maps have been relatively limited. We use in vitro selection on a pool of short RNA sequences that nearly saturates sequence space to reconstruct the form of a comprehensive fitness landscape. We also study mutations during non-enzymatic polymerization to understand how early RNA replicators would ‘move’ in sequence space.     

Carbon-13 NMR studies of 13CO binding to human hemoglobin

In the ¹³C NMR spectrum of hemoglobin A carbonylated with ¹³CO, separate resonances can be distinguished at 207.04 ppm and 206.60 ppm (with respect to the ¹³C resonance of external tetramethyl-silane) for ¹³Co bound to the α and β chains of the hemoglobin tetramer. A study of the ¹³Co derivatives of the isolated α and β chains, and of the abnormal hemoglobin M_IWATE which contains α chains which are in the met [Fe(III)] form and do not bind CO, has permitted an assignment of the high field (206.60 ppm) resonance to the β chain ¹³CO and the low field one to the α chain ¹³CO. The identification of these ¹³Co resonances permits a study of the differences in the chemistry of the α and β heme units in intact hemoglobin. Some results on the differences in the redox behavior of these chains are included.     

Carbon-13 nuclear magnetic resonance spectroscopy of [2-13C]carboxymethylcytochrome c.

Horse heart cytochrome c has been carboxymethylated under various reaction conditions using [2-13C]bromoacetate. Direct analysis of reaction products using 13C nuclear magnetic resonance spectroscopy shows that the protein can be much more extensively modified than has previously been assumed. The proximity of one carboxymethylmethionine residue to the paramagnetic center of the ferric protein allows it to be distinguished from a more constant carboxymethylmethionine residue on the basis of the chemical shift of its labeled methylene group. Refolding of cytochrome c after alkylation at low pH apparently gives a different configuration of modified methionine residues within the protein compared to that produced by alkylation at neutral pH in the presence of cyanide.