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PubMed1993

Influence of hemoglobin variants and derivatives on glycohemoglobin determinations, as investigated by 102 laboratories using 16 methods.

Influences of hemoglobin (Hb) variants (HbSS, HbCC, beta-thalassemia, HbAE, HbAS, HbAC, hereditary persistent HbF) and Hb derivatives (carbamylated- and acetylated-Hbs, Schiff base, and those formed in stored blood) on results of glyco-Hb assays by 102 laboratories using 16 different methods were investigated. Affinity chromatography shows deviating results only with homozygous Hb S and C. Correct interpretation of results from patients with decreased erythrocyte half-lives requires previous knowledge on this condition. Measurements of HbA1c by HPLC and electrophoresis are obviously unsuitable for homozygous hemoglobinopathies; for heterozygous hemoglobinopathies and Hb synthesis variants, HbA1c should be expressed as percentage of HbA0 + HbA1c; abnormal Hbs are usually recognized; both carbamylated- and acetylated-Hbs interfere and Schiff base must be eliminated. Except for stored blood, all Hb variants and derivatives gave erroneous results with disposable ion-exchange columns. Dako's immunoassay is not affected by Hb derivatives; glycated Hb variants are not recognized as glyco-Hb and percentages are consequently too low. Glyco-Hb by the immunoassay of Bayer (performed by one laboratory) is not affected by Hb variants and derivatives.

Chemistry, Clinical↗
PubMed1995

[Genotyping of apolipoprotein E (alleles epsilon 2, epsilon 3 and epsilon 4) from capillary blood].

A technique to determine epsilon 2, epsilon 3 and epsilon 4 alleles expressed at the apolipoprotein E locus (apoE genotype) is described. The proposed method is convenient for detecting this polymorphism on capillary blood spots. Capillary blood is collected on absorbent paper allowing transmission by post and prolonged conservation of samples. Even when the amount of DNA is very small, double amplification by polymerase chain reaction (PCR) from a DNA fragment comprising the two polymorphic sites enables the length of the synthetized fragment to be measured the amplification of all samples to be verified, thus avoiding false interpretations resulting from a 51-base-pair fragment due to primer self-hybridization. The digestion of this fragment by Hha I restriction enzyme and electrophoresis of the digested products give an unambiguous diagnosis of the six most frequent (epsilon 2/epsilon 2, epsilon 3/epsilon 3 epsilon 4/epsilon 4, epsilon 2/epsilon 3, epsilon 2/epsilon 4, and epsilon 3/epsilon 4). Intended for genotype screening determinations, this technique is not convenient for all rare apoE variants, which must be determined by plasma isoelectrofocusing or genomic DNA sequencing. The technique may be done performed any time, even if the subject is not fasting. It avoids the difficulties of interpretation of the isoelectrophoretic patterns induced by poor conservation of the samples or the presence of sialylated isoforms of apoE or other contaminant proteins. The modest cost of the proposed technique allows determination of the apoE genotype in large series.

Alleles↗
PubMed2024

Genotypic and phenotypic characterisation of respiratory syncytial virus after nirsevimab breakthrough infections: a large, multicentre, observational, real-world study.

BACKGROUND: Nirsevimab, a long-acting monoclonal antibody, has been approved for the prevention of respiratory syncytial virus (RSV) infection in infants. In France, more than 210&#x2009;000 single doses were administered in infants younger than 1 year during the 2023-24 season. In this context, the selection and spread of escape variants might be a concern. Here, we aimed to characterise RSV associated with breakthrough infection. METHODS: We did a multicentre, national, observational study in France during the 2023-24 RSV season in RSV-infected infants (aged <1 year) who either received or did not receive a dose of nirsevimab before their first RSV season. We excluded infants with insufficient information about nirsevimab treatment or without parental consent. We used respiratory samples collected in each laboratory for full-length RSV RNA sequencing to analyse changes in the nirsevimab binding site &#xd8;. We tested clinical RSV isolates for neutralisation by nirsevimab. We analysed F candidate substitutions by fusion-inhibition assay. FINDINGS: Of the 695 RSV infected infants, we analysed 545 (78%) full-length RSV genome sequences: 260 (48%) from nirsevimab-treated breakthrough infections (236 [91%] RSV-A and 24 [9%] RSV-B) and 285 (52%) from untreated RSV-infected infants (236 [83%] RSV-A and 49 [17%] RSV-B). Analysis of RSV-A did not reveal any substitution in site &#xd8; known to be associated with resistance to nirsevimab. Two (8%) of 24 RSV-B breakthrough infections had resistance-associated substitutions: F:N208D (dominant resistance-associated substitution) and a newly described F:I64M plus F:K65R combination (minority resistance-associated substitution), both of which induced high levels of resistance in the fusion-inhibition assay. INTERPRETATION: This study is, to the best of our knowledge, the largest genotypic and phenotypic surveillance study of nirsevimab breakthrough infections to date. Nirsevimab breakthrough variants remain very rare despite the drug's widespread use. The detection of resistance-associated substitutions in the RSV-B F protein highlights the importance of active molecular surveillance. FUNDING: ANRS Maladies Infectieuses Emergentes and the French Ministry of Health and Prevention.

Humans↗
PubMed2002

Squamous cell carcinoma of the conjunctiva: clinicopathological features in 287 cases.

BACKGROUND: Squamous cell carcinoma is the most frequently encountered malignant tumour of the conjunctiva. The objective of this study was to describe the clinicopathological features of patients with squamous cell carcinoma of the conjunctiva seen at a large ophthalmologic hospital in Mexico City. METHODS: We reviewed the clinical and pathological files of all patients with documented squamous cell carcinoma of the conjunctiva seen at the hospital between 1957 and 1996. RESULTS: A total of 287 cases (286 patients) were reviewed. The mean age of the patients was 60.4 (range 12 to 99) years; 55% were male. The clinical diagnosis was accurate in 41% of cases. Typical keratinized squamous cell carcinoma of the conjunctiva accounted for 98% of the lesions, and there were small numbers of histologic variants: lymphoepithelioma-like carcinoma (three cases), spindle cell carcinoma (two cases) and mucoepidermoid carcinoma (one case). Evidence of local extension of the tumour was found in 150 patients (52%), with the cornea being most frequently involved (108 cases [38%]). Regional metastasis was found in two patients, to a submandibular lymph node in one and to a preauricular lymph node in the other. The most common form of treatment was local resection (258 cases [90%]). The mean length of follow-up was 7.7 (range 2 to 24) months. The recurrence rate was 5.2%. INTERPRETATION: We report a large series of patients with squamous cell carcinoma of the conjunctiva. The incidence of local extension was high. Three cases of lymphoepithelioma-like carcinoma, a variant not previously reported in the conjunctiva, were encountered and were confirmed by immunohistochemical reactions.

Adolescent↗
PubMedDate not supplied

Follicular variant of papillary thyroid carcinoma: a comparative study of histopathologic features and cytology results in 141 patients.

OBJECTIVE: To characterize the histopathologic features of follicular variant of papillary thyroid carcinoma (FVPC) and its cytology results on fine-needle aspiration (FNA) biopsy and compare them with those of papillary thyroid carcinoma (PC). METHODS: We searched the University of Massachusetts Medical Center pathology database for all surgical specimens associated with a diagnosis of FVPC or PC between January 1992 and February 1998 and reviewed the related pathology reports. In addition, the associated preoperative FNA results were analyzed. RESULTS: On initial assessment, FVPC was associated with a significantly lower incidence of cervical lymph node metastatic involvement in comparison with PC (5.6% versus 35.7%; P<0.001). Even though the mean size of FVPC was larger than that of PC (2.57 cm versus 1.75 cm; P<0.05), FVPC showed a lower incidence of thyroid capsule invasion (5.6% versus 11.4%), infiltrative resection margins (2.8% versus 20.0%; P = 0.01), local soft tissue invasion (7.0% versus 25.7%; P<0.005), and multicentricity (25.4% versus 47.1%; P<0.01). Lymphocytic thyroiditis was a common feature of both FVPC (36.6%) and PC (35.7%). FNA biopsy revealed the presence of malignant cells in 9.8% of patients with FVPC in comparison with 67.5% of patients with PC. Most cytology specimens of FVPC (58.8%) were interpreted as suspicious for a malignant lesion or as a follicular neoplasm. CONCLUSION: FVPC is associated with a significantly lower incidence of cervical lymph node metastatic lesions and invasive histologic features than is PC. Long-term prospective clinical studies are needed to determine whether these findings translate into a more benign natural history for this variant of PC. Results of FNA biopsy in FVPC are more commonly interpreted as suspicious rather than malignant; this factor has major implications for preoperative planning.

Biopsy, Needle↗
PubMedDate not supplied

Verrucous carcinoma of the oral cavity.

Since verrucous carcinoma was first identified as a distinct clinicopathologic entity, a great deal of confusion has developed in interpreting the proper criteria for diagnosis. Various authors, therefore, have developed considerably different concepts of the features that make this lesion a unique variant of squamous cell carcinoma. Consequently, there is great confusion in the literature as to the appropriate therapeutic approach, the incidence of recurrence, and the frequency of anaplastic transformation of verrucous carcinoma. The literature was reviewed to identify all cases of verrucous carcinoma of the oral cavity that appear to meet the clinical and histopathologic criteria for this lesion as originally set forth by Ackerman. The problems encountered in arriving at the diagnosis of verrucous carcinoma are discussed. Cases with at least a 1-year reported follow-up were grouped according to the primary modality of therapy employed and were evaluated as to the effectiveness of the initial therapy. The frequency of anaplastic transformation following radiation therapy is also addressed.

Adult↗
PubMed1975

Two complex translocations in chronic granulocytic leukemia involving chromosomes 22, 9, and a third chromosome.

Among 13 Ph-positive cases of chronic granulocytic leukemia (CGL), banding studies revealed two with complex rearrangements involving translocation of the long arm of number 22 to another autosome and a segment of that chromosome translocated to the long arm of number 9. In a patient with both CGL and sickle cell anemia, the 3-way rearrangement involved chromosomes 5, 9, and 22; and he also had a second Philadelphia chromosome and two constitutional variants: pericentric inversion of the other number 9 chromosome and satellite polymorphism in the G group. The karyotype of the leukemic cells was interpreted as: 47,XY,inv(9) (p11q13),t(5;9;22)(q13;q34;q11)+del(22)(q11). In the second patient, the complex translocation in the Ph-positive cells involved chromosomes 3, 9, and 22, resulting in a karyotype interpreted as: 46,XX,t(3;9;22)(p21;q34;q11). Several reports indicate that an abnormality of chromosome 9 is not essential for the development of Ph-positive CGL, but the very high frequency of its involvement (including these unusual translocations) suggests that some type of non-random somatic association may exist between 9q and 22q which makes simultaneous breakage likely. Attempts to correlate specific types of pH chromosome rearrangements with the clinical course of CGL must await the identification of more cases and longer follow-up.

Adult↗
PubMed2002

Diversity of the penaeidin antimicrobial peptides in two shrimp species.

Penaeidins, a unique family of antimicrobial peptides (AMPs) with both proline and cysteine-rich domains, were initially identified in the hemolymph of the Pacific white shrimp, Litopenaeus vannamei. Described here are the results of an investigation of penaeidin diversity in individual shrimp from two species, L. vannamei and L. setiferus (Atlantic white shrimp). We report the discovery of a novel penaeidin class, designated penaeidin 4 present in both L. vannamei and L. setiferus, and that all penaeidin classes were expressed in a single individual. In addition, nearly all penaeidins, regardless of class, shared an identical leader sequence while differing dramatically in the remainder of the peptide. Several new class 3 isoforms were identified, as well as sequence variants of Lv3a, which differ in the 3' untranslated region. Penaeidin sequence variability (especially of class 3), within and between individuals, is not interpretable as simple allelic polymorphism and may reflect alternate transcriptional mechanisms. Penaeidins are encoded by a small number of genetic loci and are not likely representatives of a large gene family produced by whole gene duplication, but rather may be products of a multi-component locus. Based on phylogenetic analysis, penaeidins fall into three classes where 1 and 2 are combined while classes 3 and 4 remain distinct. Phylogenetic analysis indicates that all classes of penaeidin were likely present in both species prior to speciation.

Amino Acid Sequence↗
PubMed2006

Nice wor_ if you can get the wor_: subliminal semantic and form priming in fragment completion.

Two experiments investigated subliminal semantic and form priming in a word-completion task. Visual gap-words with a dominant and a subordinate solution were preceded by form-related or by semantically related words, which were briefly presented and sandwich-masked. Priming of the subordinate solution was assessed in Experiment 1, relative to a neutral condition. Both solutions were primed in Experiment 2. In the absence of conscious prime recognition, both semantic and form primes reliably increased the probability with which the primed solution was given. With our variant of fragment-completion, response priming can be ruled out as explanation. Moreover, effects were already present at first presentation, excluding an interpretation in terms of partial awareness due to massive repetition. The data demonstrate automatic activation at both form and semantic levels in the absence of conscious awareness.

Adult↗
PubMed1998

Emergence of algorithmic language in genetic systems.

In genetic systems there is a non-trivial interface between the sequence of symbols which constitutes the chromosome, or 'genotype', and the products which this sequence encodes--the 'phenotype'. This interface can be thought of as a 'computer'. In this case the chromosome is viewed as an algorithm and the phenotype as the result of the computation. In general, only a small fraction of all possible sequences of symbols makes any sense for a given computer. The difficulty of finding meaningful algorithms by random mutation is known as the brittleness problem. In this paper we show that mutation and crossover favor the emergence of an algorithmic language which facilitates the production of meaningful sequences following random mutations of the genotype. We base our conclusions on an analysis of the population dynamics of a variant of Kitano's neurogenetic model wherein the chromosome encodes the rules for cellular division and the phenotype is a 16-cell organism interpreted as a connectivity matrix for a feed-forward neural network. We show that an algorithmic language emerges, describe this language in extenso, and show how it helps to solve the brittleness problem.

Algorithms↗
PubMed2006

[Ultrasound evaluation of the acromioclavicular joint--a correlation of anatomical and sonographical findings].

AIM: To compare ultrasound imaging to the anatomy of the acromioclavicular joint. METHODS: 13 cadaveric acromioclavicular joints were examined by ultrasound (11 MHz linear array transducer) to determine the limits of the joint capsule and the width of the joint space. The results were compared to macroscopic sections. RESULTS: Anatomical variations were observed. The joint space of one specimen was completely filled by fibrous tissue, leaving 12 specimens for a complete study. A hypoechoic meniscoid disc was attached to the superior joint capsule, resulting in a convex curvature of the cranial part. The mean sonographic width of the joint space was 3.9 mm +/- 1.7 mm standard deviation (SD). The mean distance of the joint capsule from the articular bone rim of the clavicle, the acromion, and from the middle of the joint space was 1.1 +/- 1.0 mm, 1.3 +/- 0.7 mm, and 2.1 +/- 0.9 mm, respectively. The distance from the joint space to the capsular insertion on the clavicle and on the acromion was 4.4 +/- 1.4 mm and 5.3 +/- 2 mm, respectively. The mean difference between ultrasound and anatomical measurements in the vertical (cranio-caudal) plane was 0.5 +/- 0.5 mm (SD), whereas the mean difference between measurements in the horinzontal (medio-lateral) plane was 1.3 +/- 1.1 mm (SD). CONCLUSION: Due to low cost, safety and wide availability, sonography is suited for the evaluation of the acromioclavicular joint. However, when interpreting the results, errors in measuring, limitations in resolution of the system used, and the anatomy of the acromioclavicular joint and its anatomical variants have to be taken into consideration.

Acromioclavicular Joint↗
PubMed1996

FDG-PET screening for cerebral metastases in patients with suspected malignancy.

2-(18)F-Fluoro-2-deoxy-D-glucose (FDG) positron emission tomography (PET) is increasingly being used in the evaluation of patients with malignancy. Recently, imaging protocols have incorporated ¿whole-body' views acquired over multiple steps. However, with this strategy, brain metastases can potentially go undetected. The aim of this study was to determine whether a supplementary 10-min brain 18F-FDG scan provides additional clinically useful information. Accordingly, we reviewed the studies of 273 patients with various malignancies in whom both whole-body and brain images were performed. Whole-body and regional attenuation-corrected 18F-FDG images were obtained approximately 60 min post-injection. A separate 10-min scan of the brain was subsequently performed. All studies were performed using a standard PET scanner with the images being interpreted by consensus of at least two experienced observers. Altogether, 119 studies were reported as normal (n = 96) or showing anatomic or normal variants (n = 23). Abnormalities involving extracranial organs were identified in 149 (55%) patients. Cerebral metastases were reported in 4 (1.5%) patients, only two of which (0.7%) were unsuspected prior to the PET scan. Incidental pathology (encephalopathy, infarct) was reported but unconfirmed in two further patients (0.7%). We conclude that routine ¿screening' for cerebral metastases in patients with suspected malignancy has a low yield and may not be clinically useful.

Adolescent↗
PubMed2002

Molecular dynamics study of cage decay, near constant loss, and crossover to cooperative ion hopping in lithium metasilicate.

Molecular dynamics (MD) simulations of lithium metasilicate (Li2SiO3) in the glassy and supercooled liquid states have been performed to illustrate the decay with time of the cages that confine individual Li+ ions before they hop out to diffuse cooperatively with each other. The self-part of the van Hove function of Li+ ions, G(s)(r,t), is used as an indicator of the cage decay. At 700 K, in the early time regime t of Li+ ions also increases very slowly with time approximately as t(0.1) and has weak temperature dependence. Such can be identified with the near constant loss (NCL) observed in the dielectric response of ionic conductors. At longer times, when the cage decays more rapidly as indicated by the increasing buildup of the intensity of G(s)(r,t) at the distance between Li+ ion sites, broadly crosses over from the NCL regime to another power law t(beta) with beta approximately 0.64 and eventually it becomes t(1.0), corresponding to long-range diffusion. Both t(beta) and t(1.0) terms have strong temperature dependence and they are the analogs of the ac conductivity [sigma(omega) proportional, variant omega(1-beta)] and dc conductivity of hopping ions. The MD results in conjunction with the coupling model support the following proposed interpretation for conductivity relaxation of ionic conductors: (1) the NCL originates from very slow initial decay of the cage with time caused by few independent hops of the ions because t(x1)< and are about the same for t of the fast ions increases much more rapidly for t>t(x2). The self-part of the van Hove function of Li+ reveals that first jumps for some Li+ ions, which are apparently independent free jumps, have taken place before t(x2). While after t(x2) the angle between the first jump and the next is affected by the other ions, again indicating cooperative jump motion. The dynamic properties are analogous to those found in supercooled colloidal particle suspension by confocal microscopy.

Journal Article↗
PubMed1989

Mitral leaflet billowing and prolapse: its prevalence around the world.

Primary mitral leaflet billowing, or so-called mitral valve prolapse, has become the most common valve anomaly in the United States and is also frequently found throughout the world. Its prevalence varies from less than 1% to 38%, differing not only between countries but also within the same country. The prevalence depends on whether the study is clinical or echocardiographic, based on autopsy or surgical material, or of hospital or non-care-seeking population. Other explanations for the varying prevalence are the age, sex and weight differences of the study population, imprecise terminology, the care with which auscultation and/or echocardiography are carried out and interpreted, and some selection biases. Although prevalent throughout the world, the condition is generally benign and can often be regarded as a normal variant. Among the complications of mitral valve prolapse, progressive mitral regurgitation and infective endocarditis are particularly noteworthy. Primary mitral valve prolapse is currently a leading cause of mitral regurgitation and also of infective endocarditis.

Adult↗
PubMed2005

Cutaneous melanocytic lesions: selected problem areas.

Cutaneous melanocytic proliferations are diverse morphologically, and their behavioral attributes may be difficult to discern with certainty. As a consequence, diagnostic anatomic pathologists regularly encounter problems in the interpretation of such lesions. This review considers several selected issues in that subject area, including proliferative congenital nevi, architecturally disordered (dysplastic) nevi, morphologic variants of Spitz nevus, atypical lentiginous melanocytic proliferations, nevoid melanoma, diagnostically deceptive histologic variants of melanoma, "epidermotropic" metastases of melanoma, and the relationship of melanoma microstages to tumor growth phases.

Cell Proliferation↗
PubMedDate not supplied

Pineal germinomas and testicular seminoma: a comparative ultrastructural study with special references to early carcinomatous transformation.

We have investigated the ultrastructural characteristics of 16 cases of pineal germinomas and compared them with those of 18 cases of testicular seminomas. Glandular differentiation of tumor cells was found in both though it was more consistently noted in pineal germinomas than in testicular seminomas. This feature was interpreted to represent early carcinomatous transformation of germinoma cells. It not only explains the difficulties occasionally encountered in distinguishing germinoma and its anaplastic variant from embryonal carcinoma, but also has implications for our understanding of germ cell neoplasia, particularly the place of germinoma/seminoma in the nosology of such tumors.

Brain Neoplasms↗
PubMedDate not supplied

[Clinical radiological analysis of 99mTc-technetryl myocardial scintigraphy].

Resting and exercise 99mTc-technetryl myocardial scintigraphies were performed in 145 patients with various cardiovascular diseases. Normal lowered and elevated radioopaque accumulations were found to be present in both coronarogenic and noncoronarogenic diseases. Four degrees of agent hypofixation and four types of stress myocardial scintigraphies were interpreted from clinical points of view. Coronary failure is characterized by more severe hemoperfusion disorders (degrees 3-4) and the 3rd-4th variant of stress myocardial scintigraphy.

Humans↗