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Microbial growth on C1 compounds. Uptake of [14C]formaldehyde and [14C]formate by methane-grown Pseudomonas methanica and determination of the hexose labelling pattern after brief incubation with [14C]methanol.

1. A study has been made of the incorporation of carbon from [(14)C]formaldehyde and [(14)C]formate by cultures of Pseudomonas methanica growing on methane. 2. The distribution of radioactivity within the non-volatile constituents of the ethanol-soluble fractions of the cells, after incubation with labelled compounds for periods of up to 1min., has been analysed by chromatography and radioautography. 3. Radioactivity was fixed from [(14)C]formaldehyde mainly into the phosphates of the sugars, glucose, fructose, sedoheptulose and allulose. 4. Very little radioactivity was fixed from [(14)C]formate; after 1min. the only products identified were serine and malate. 5. The distribution of radioactivity within the carbon skeleton of glucose, obtained from short-term incubations with [(14)C]methanol of Pseudomonas methanica growing on methane, has been investigated. At the earliest time of sampling over 70% of the radioactivity was located in C-1; as the time increased the radioactivity spread throughout the molecule. 6. The results have been interpreted in terms of a variant of the pentose phosphate cycle, involving the condensation of formaldehyde with C-1 of ribose 5-phosphate to give allulose phosphate.

Carbon Isotopes↗

Molecular phylogeny of part of the env gene of HIV-1 strains isolated in Côte d'Ivoire.

OBJECTIVES: To examine the genetic variation of HIV-1 isolates in Abidjan, Côte d'Ivoire, and to determine the extent to which phylogenetic trees based on sequence information of part of the env gene containing the principal neutralizing domain are representative for documenting genetic variability. DESIGN: Phylogenetic comparison of 13 HIV-1 strains isolated from patients in Abidjan with previously documented HIV-1 strains of different geographic origin. METHODS: To sequence a 900 base-pair fragment of the env gene containing V3, V4, V5 and the beginning of gp41 of three to four clones per isolate. Phylogenetic tree analysis was performed with the software package TREECON. RESULTS: Eleven HIV-1 isolates of Abidjan were classified as genotype A, while two were classed as genotypes B and D. Intra-genotype A distances at the nucleotide level were a maximum of 14.1%. Inter-genotype distances between genotype A and genotypes B, C, and D varied from 16.0 to 22.6%. Phylogenetic trees, based on sequence data of a 300 base-pair fragment containing the V3 loop, showed significant differences in tree topology and statistical confidence with phylogenetic trees based on sequence data of the 900 base-pair env fragment. CONCLUSIONS: Genotype A Côte d'Ivoire HIV-1 strains, which comprise 11 out of 13 isolates, predominate in Abidjan, which may indicate a local burst of particular variants. Phylogenetic trees should be interpreted with caution when based on a more limited number of nucleotides, such as the V3 region.

Base Sequence↗

Lymphocyte predominance Hodgkin's disease: a reappraisal based upon histological and immunophenotypical findings in relapsing cases.

The clinical, morphological and immunological findings in nine cases of relapsing lymphocyte predominance Hodgkin's disease (LPHD) are examined. Six patients had initial biopsies demonstrating nodular lymphocytic and/or histiocytic (L&H) LPHD; Leu-M1 was not expressed by any of the atypical cells in these cases. All six demonstrated one or more recurrences of nodular L & H LPHD; four are currently free of disease, one died of non-Hodgkin's lymphoma and another died of leukaemia. Two patients had initial biopsies demonstrating diffuse LPHD, with only rare multilobated atypical cells (L & H variants). Both patients had recurrences interpreted as mixed cellularity Hodgkin's disease, 10 and 15 years after initial therapy and both died with lymphocyte depleted Hodgkin's disease. The atypical cells in the initial biopsies and in subsequent recurrences failed to express Leu-M1, but did express leukocyte common antigen. The initial biopsy from the final patient was histologically interpreted as focal involvement by LPHD, but interfollicular Hodgkin's disease was considered after the Leu-M1 stain revealed additional atypical cells. The disease relapsed and the patient died with typical nodular sclerosing Hodgkin's disease. The pattern of the relapses supports the concept that the histological entity of LPHD may include several distinct clinicopathological subgroups.

Biopsy↗

Preoperative evaluation of living kidney donors using multirow detector computed tomography: comparison with digital subtraction angiography and intraoperative findings.

To assess the accuracy of multirow detector computed tomography (MDCT) for the evaluation of renal anatomy for preoperative donor assessment in living related kidney transplantation. MDCT-scans (4- and 16-slice-CT) of 51 consecutive living kidney donors (age, 51.6 +/- 9.7 years; range, 28-68 years) were analysed by three blinded observers and compared with digital subtraction angiography (DSA) and surgery. Contrast-enhanced MDCT was performed with 1 mm slice thickness reconstruction interval during arterial and venous phases. Supernumerary renal arteries, veins, early branching of vessels and abnormalities of the ureters were documented. The overall accuracy of computed tomography angiography (CTA) for detection and classification of surgically relevant arterial variants was 97% (99/102). The interpretation of 16-channel MDCT images was correct in all cases (accuracy, 100%), while the four-channel CTA had three incorrect results regarding the differentiation of early branching vessels from double renal arteries (accuracy, 93%). The overall accuracy of DSA was 91%. Renal vein abnormalities were correctly diagnosed with MDCT in 100% compared with 89% correct findings with DSA. There were three kidneys with incomplete ureter duplication, detected both with MDCT and DSA. MDCT demonstrated superior accuracy compared with non-selective DSA for the preoperative assessment of renal anatomy in living kidney donors; and for the distinction of supernumerary arteries versus early branching patterns, 16-channel CTA data were better than those of the four-channel system.

Adult↗

MTS1 gene mutations in archival oral squamous cell carcinomas.

Multiple tumor suppressor gene 1 (MTS1) has been found mutated or deleted in a variety of human cancers. Our purpose was to identify and characterize MTS1 gene mutations in primary oral squamous cell carcinomas (SCCs) in each of the three exons of the MTS1 gene. Seventeen archival samples of oral SCC were evaluated for the presence of MTS1 mutations using single strand conformation polymorphism (SSCP) and DNA sequencing. Three of 17 tumors exhibited MTS1 gene mutations: one tumor exhibited a mutation in exon 2 and two tumors exhibited mutations at the splice site junction of intron 2 and exon 3. Three tumors also exhibited a common base change in the 3' untranslated region of exon 3, which is interpreted as a likely polymorphic variant. An examination of the three tumors exhibiting MTS1 point mutations revealed no unique characteristics relative to p53 immunohistochemical activity, mitotic frequency, or degree of histologic differentiation. This study indicates that MTS1 gene mutations may be involved in at least a minor proportion of oral SCCs.

Adolescent↗

Electroencephalographic variants and genetic predisposition to schizophrenia.

Schizophrenic patients (249) were divided into those with and those without a family history of major functional psychosis. The same patients were then divided into those with entirely normal electroencephalograms and those whose traces contained some variant of normal. Traces were interpreted without knowledge of the patients' identities, and the question of the presence or absence of positive heredity had been decided without knowledge of the patients' electroencephalographic status, so that the discovery that normal electroencephalograms correlated highly significantly with positive heredity, and vice versa, commands attention. It is considered in the setting of previous work on psychoses and organic and electroencephalographic findings.

Brain↗

"Lumps" and "bumps" that mimic acute aortic and brachiocephalic vessel injury.

Laceration of the thoracic aorta or brachiocephalic vessels due to blunt trauma is relatively common. In such cases, prompt and accurate diagnosis followed by timely surgery is essential. These injuries typically occur at the aortic isthmus and can usually be readily identified at aortography, which remains the standard of reference for diagnosis. However, numerous anatomic variants that manifest as "lumps" or "bumps" on aortograms can mimic true vascular injury, thereby leading to false-positive or false-negative diagnosis. These variants include aortic spindle, classic or atypical ductal diverticula, and infundibula of the brachiocephalic arteries and adjacent branches or of the right third intercostal artery. Ductus diverticula typically occur at the isthmus and have smooth, uninterrupted margins with gently sloping shoulders. Infundibula are also smoothly marginated but can occur in a variety of locations and generally taper into one or more vessels at their apex. Knowledge of the imaging appearances of these anatomic variants is necessary for correct interpretation of aortograms of the aorta and brachiocephalic vessels in blunt trauma patients.

Adult↗

Echocardiographic appearance of the Chiari network: differentiation from right-heart pathology.

As echocardiography is being used more often, its value and accuracy are becoming more fully appreciated. Coincident with wider application of this imaging technique is the potential for identifying normal anatomic variants and their possible erroneous interpretation as pathologic states. In this report we describe the M-mode and two-dimensional echocardiographic features of a congenital remnant known as the Chiari network. This structure can present as a highly mobile, highly reflectant echo target that can be seen in several locations in the right atrium. We report here an index case that could be well examined echocardiographically and that was a cause of considerable concern due to the presence of congestive heart failure and a history of staphylococcal endocarditis. The presence of the Chiari network was confirmed pathologically. Subsequently, we found similar echocardiographic findings in 19 of 1248 patients (1.5%) studied in our laboratory. This congenital remnant, which is found pathologically in 2-3% of normal hearts, could be confused with valve disruption, vegetation or other mass lesion, particularly when associated with a suggestive clinical situation.

Adult↗

Functional interdependence of pseudopodia in Amoeba proteus stimulated by light-shade difference.

Polytactic cells of Amoeba proteus were exposed to localized photic stimulation. When a pseudopodium is stimulated to advance, by shading it, other pseudopodia are retracted. Activation of the shaded front is the primary response, and contraction of other fronts the secondary one. When a pseudopodium is inhibited by illuminating its frontal segment, or when it is allowed to enter the bright zone in the course of migration, it slows down and stops but its eventual retraction depends on the existence of other possible directions for the endoplasmic flow. Therefore, if other active pseudopodia are lacking, the front suppressed by light cannot retreat effectively until new fronts arise in other body regions kept in shade. In all experimental situations the development of new fronts or the activation of forward flow in lateral pseudopodia precedes the contraction of the former leading pseudopodium. Also the reversal of direction of the endoplasmic streaming begins at the new front, and then it gradually extends until it reaches the former front. The results confirm the interdependence of different pseudopodia in the same individual and they contradict the concept that pseudopodia behave as separate functional units. On the other hand, they indicate that formation of new pseudopodia should not be explained as a simple secondary effect of contraction of the older ones but, on the contrary, as a phenomenon that initiates the changes in the pattern of flow in amoeba. The general interpretation is based on this variant of the pressure-flow theory of amoeboid movement, which attributes the motive power to the contractile activity of the whole cell cortex and the steering role to events taking place in the front of the migrating cell.

Amoeba↗

MR diagnosis of meniscal tears: analysis of causes of errors.

OBJECTIVE: MR imaging of the knee is an accurate method for diagnosing meniscal tears. However, MR findings do not always agree with surgical findings. In a retrospective study, we analyzed the various causes of incorrect MR diagnoses. MATERIALS AND METHODS: We reviewed a series of 400 MR examinations for suspected meniscal tears in which the diagnostic accuracy was 90%. In this group, we found 70 patients in whom the original MR diagnosis did not agree with the surgical findings. Three musculoskeletal radiologists independently reviewed each of the 70 MR examinations without knowledge of the original interpretation or the surgical findings. Their interpretations and the MR images then were correlated with the surgical findings. The original incorrect diagnoses were categorized as being due to unavoidable errors, errors in interpretation, or errors made because of equivocal MR findings of a tear. Unavoidable errors were defined as false-positive and false-negative diagnoses that could not be avoided, even in retrospect. RESULTS: Of the 83 original diagnostic errors made in the MR evaluation of 800 menisci, 33 (40%) were unavoidable errors, 32 (39%) were due to equivocal MR findings, and 18 (21%) were due to interpretation errors. The unavoidable errors consisted of 21 missed meniscal tears and 12 false-positive MR diagnoses. In the false-positive cases, the menisci were interpreted as torn on MR images by all three observers, but no tear was found at arthroscopy. Subtle MR findings that were equivocal for a tear caused both false-positive and false-negative diagnoses. Seven of the 18 interpretation errors occurred when normal variants were mistaken for a tear. CONCLUSION: Using conventional coronal and sagittal spin-echo MR imaging, we could not identify 21 (6%) of the 333 meniscal tears, even in retrospect. In addition, subtle findings that are equivocal for a tear may still make MR diagnosis of every torn meniscus difficult even for experienced radiologists. Unavoidable false-positive diagnoses due to healed tears or tears missed at arthroscopy are an infrequent problem occurring in only 1.5% of the original 800 menisci evaluated with MR imaging.

Diagnostic Errors↗

[Structure of flower in Arabidopsis thaliana: spatial pattern formation].

Morphological analysis of flowers was carried out in Arabidopsis thaliana wild type plants and agamous and apetala2 mutants. No direct substitution of organs takes place in the mutants, since the number and position of organs in them do not correspond to the structure of wild type flower. In order to explain these data, a notion of spatial pattern formation in the meristem was introduced, which preceded the processes of appearance of organ primordia and formation of organs. Zones of acropetal and basipetal spatial pattern formation in the flower of wild type plants were postulated. It was shown that the acropetal spatial pattern formation alone took place in agamous mutants and basipetal spatial pattern formation alone, in apetala2 mutants. Different variants of flower structure are interpreted as a result of changes in the volume of meristem (space) and order of spatial pattern formation (time).

AGAMOUS Protein, Arabidopsis↗

Imaging anatomy of the ankle.

The purpose of this short review is to give an overview of the normal imaging anatomy of the ankle and the foot, required to understand pathologic conditions. The anatomy of the ankle and foot reflects the specific needs of the complex biomechanics of walking and running. Therefore, a short discussion of the biomechanics will precede the description of the ankle anatomy. For didactical reasons, the anatomic structures of the ankle and foot will be divided into medial, lateral, anterior and posterior compartments to help the reader conceptualise the particularly complex anatomy, and to describe the different structures in relation to each other. In a the second part the normal variants, which should not be interpreted as pathologic changes, will be discussed.

Ankle↗

[Duodenocolonic fistula caused by carcinoma of the cecum].

Duodenocolonic fistulas of malignant origin are an uncommon finding. The point of origin of the fistula is almost always cancer of the hepatic angle of the colon. We report a patient with this rare entity which originated from a cecal carcinoma, and interpret it as an anatomic variant of the subhepatic position. The cases published are reviewed and the difficulties of reaching a therapeutic decision once the diagnosis is established are highlighted.

Carcinoma↗

[Incontinentia pigmenti achromians (systematized depigmented nevus)].

Two girls of 1 1/2 und 4 years age and described with linear, arch-like depigementations which appeared in early childhood. In both children no additional abnormalities could be found. The problem of terminology is briefly discussed, and it is proposed to interpret this syndrome as a variant of a systematized naevus depigmentosus. There seems to be no justification for turning this clinical entity into a new syndrome, when the only clinical signs are the characteristic depigmentations without any additional abnormalities.

Child, Preschool↗

Potential diagnostic pitfalls caused by blood film artifacts in prolymphocytic leukaemia. Observations in two cases.

The diagnosis of lymphoproliferative disorders is based on a combined evaluation of the clinical, immunological and morphological findings. Cytological details may vary with the quality of the smear. We report two cases of prolymphocytic leukaemia in which cytoplasmic hairs or protrusions were observed when the films were not dried quickly. In one case the artifacts led to an initial erroneous interpretation of hairy cell leukaemia 'variant'. The cytoplasmic outline was smooth in both cases when the smears were immediately fan-dried. The findings underscore the necessity of high standards of excellence, even for the simple technique of blood film preparation, in order to avoid undesirable artifacts which may result in diagnostic misinterpretation.

Aged↗

[Vater or Vacterl syndrome (author's transl)].

Analysis of malformations in 65 newborns with limb anomalies, 39 with esophageal atresia with tracheoesophageal fistula, and 41 with anal atresia confirmed the nonrandom tendency for the defects of the VATER or VACTERL syndrome to associate together. 11 new patients with 4 or more of these anomalies were compared with 41 previously reported cases. There was good agreement with reference to the frequency of the major malformations noted in the VACTERL association. While anal atresia was not so common in our patients, cardiac anomalies and radial limb dysplasia occurred somewhat more frequently. In accordance with previous findings we also emphasize a single umbilical artery as one of the malformations in the spectrum of the VACTERL association (V = vertebral defects and vascular anomalies). Because of the high incidence of rib anomalies in our patients and in earlier cases with complete medical records it is suggested that the scope of the VACTERL association should be enlarged by this malformation. Thus the R in VACTERL would stand not only for renal defects but als for rib anomalies. Furthermore, the spectrum of anomalies could be extended by auricular defects (A = anal atresia and auricular defects). When one of these VACTERL components is found attention should be drawn to the possibility of the presence of the other associated anomalies. The developmentally correlated malformations seen in the VACTERL syndrome are generally sporadically observed. At the present time the etiology is unknown but heterogeneity is suggested. Although a causal relationship between maternal intake of progesteron/estrogen during the vulnerable period of embryogenesis and the VACTERL syndrome has been suggested, none of the mothers of our patients were exposed to these hormones during early pregnancy. Cytogenetic investigation in one patient and his mother showed a so-called marker chromosome 9 (C9qh+ variant) which is difficult to interpret at the present time.

Abnormalities, Multiple↗

Human alcohol dehydrogenase ADH1, ADH2 and ADH3 loci in a mixed population of Bahia, Brazil.

1. The three structural gene loci of human alcohol dehydrogenase have been studied in liver, jejunum and lung from 300 newborns in a triracially mixed population of Bahia, Brazil. 2. The frequency of the ADH23 allele was 0-1392, suggesting that the ADH23 allele is less frequent in Negroes. 3. A new ADH2 variant was identified. The electrophoretic pattern was interpreted as due to a new allele which is provisionally called ADH2Bahia. 4. By electrophoretic classification the 'atypical' variant was found in 2-8% of the sample. A question is raised regarding the ancestral origin of the 'atypical' variant in the population. Because this variant is common in Japanese it may have reached the present day population of Bahia through their American Indian ancestors. 5. Subjective estimation of the proportions of beta chains by giving scores to the liver isozymes alphaalpha, alphabeta and betabeta showed a clear relationship between the fetal weight and the beta chain activity. 6. The proportion of beta chains in the liver is significantly less when there is no enzyme activity in the lung, indicating some synchronous 'turning on' mechanism for alcohol dehydrogenase synthesis in both tissues.

Alcohol Oxidoreductases↗

Variation of some serum proteins in red deer, Cervus elaphus L.

Various electrophoretic techniques, immunoblotting and inhibitions of trypsin and chymotrypsin were used to study the variability of serum proteins in farmed red deer, Cervus elaphus L., of Czechoslovakian origin. Easily interpretable polymorphisms were observed in transferrin (variants A, B1, B2, C) and vitamin D binding protein, GC (variants D, F, I, S). Great variability was observed in the protease inhibitors PI2, PI3, PI4, PI5, and PI8 and in unidentified zones in the vicinity of albumin, but no genetical or physiological interpretation for this variability is yet available. Haemopexin, alpha 1 glycoprotein, protease inhibitors PI1, PI6 and PI7 were monomorphic.

Alleles↗