Low-resistance endometrial arterial flow in the exclusion of ectopic pregnancy revisited.

The objective of this study was to evaluate the efficacy of endometrial arterial flow in the exclusion of ectopic pregnancy. From October 1997 to June 1999, 66 women with elevated beta-human chorionic gonadotropin titers and clinical indications of ectopic pregnancy were evaluated by endovaginal sonography. Women with a gestational sac containing an embryo, a yolk sac, or both were excluded from the study. Doppler ultrasonography was performed in the remaining cases when a definite intrauterine pregnancy could not be visualized. In all cases the thermal index was kept to less than 1.0, consistent with as-low-as-reasonably-achievable principles. Trophoblastic flow was defined as a resistive index of less than 0.6 within the endometrium. Statistical analysis was performed using a 2-tailed t test. Twenty women had ectopic pregnancies; 33 had spontaneous pregnancy losses; and 13 had normal intrauterine pregnancies. A total of 29 women had endometrial trophoblastic flow: 11 of 13 with intrauterine pregnancies, 1 of 20 with ectopic pregnancies, and 17 of 33 with spontaneous pregnancy losses. The negative predictive value for the presence of endometrial low-resistance flow for excluding ectopic pregnancy was 97%. The presence of low-resistance arterial endometrial flow can be a useful sign in diagnosing an early intrauterine pregnancy and decreasing the probability that an ectopic pregnancy is present, particularly in patients with otherwise normal ultrasonographic findings.

Usefulness of the double-wall sign in detecting pneumothorax in patients with giant bullous emphysema.

OBJECTIVE: We describe a new sign improving detection of pneumothorax in patients with giant bullous emphysema: air surrounding both sides of the bulla wall (the intrathoracic equivalent of the double-wall sign of pneumoperitoneum). We report the radiographic and CT appearances of the double-wall sign in seven patients with giant bullous emphysema, four of whom had pneumothorax. CONCLUSION: Recognizing the double-wall sign of pneumothorax should aid in the triage of patients with giant bullous emphysema.

Use of ultrasonography versus magnetic resonance imaging for tendon abnormalities around the ankle.

A prospective study was performed on 28 patients who underwent surgery for tendon disorders around the ankle. Preoperatively, all patients had real-time, high resolution ultrasonography performed with a 7.5 or 10 mHz transducer. Twenty of these patients also had a preoperative magnetic resonance imaging (MRI) examination of the ankle. A total of 54 tendons were inspected intraoperatively, revealing a total of 24 intrasubstance or complete tendon tears. These surgical findings were compared with the ultrasound and MRI findings, from which the sensitivity, specificity, and accuracy were calculated for both modalities. Ultrasound produced results with a sensitivity measurement of 100%, specificity of 89.9%, and accuracy of 94.4%. MRI produced results with a sensitivity measurement of 23.4%, specificity of 100%, and accuracy of 65.75%. Ultrasound results were more sensitive and accurate than MRI in the detection of ankle tendon tears in our study.

Ultrasonographic-surgical correlation of ankle tendon tears.

This study evaluates the accuracy of ultrasonography in detecting ankle tendon tears of the peroneal, posterior tibial, and flexor digitorum longus tendons based on operative findings and clinical follow-up. A prospective study was performed in 33 patients with clinically suspected tendon injury. Sixty-eight tendons were evaluated sonographically. The diagnosis of an intrasubstance tear was made when disruption of uniform tendon architecture by hypoechoic linear or globular clefts was observed. Criteria used to diagnose complete tendon rupture included discontinuity or gap within the tendon or complete nonvisualization of the tendon. Treatment decisions were based on a combination of clinical parameters and imaging studies. Twenty-six patients had the presence or absence of tear confirmed at surgery. Five patients had a final diagnosis based on clinical findings, and two were lost to follow-up. Of the 68 tendons evaluated sonographically, 54 were directly inspected at surgery; 20 were found to be torn and 34 were intact. Ultrasonography was able to identify all tears correctly with an accuracy of 93%, a sensitivity of 100%, and a specificity of 88%. The positive and negative predictive values were 83% and 100%, respectively. The combined accuracy, sensitivity, and specificity of ultrasonography in detecting tendon tears in all patients evaluated both surgically and by clinical follow-up were 94%, 100%, and 90%, respectively.

Sequence and rate of bone marrow conversion in the femora of children as seen on MR imaging: are accepted standards accurate?

OBJECTIVE: The purpose of this study was to reassess the normal sequence and rate of marrow conversion in the femora of children as depicted on MR imaging. MATERIALS AND METHODS: We retrospectively analyzed 81 T1-weighted MR images of the femur for the appearance and distribution of hematopoietic (red) and fatty (yellow) marrow. Eighty-one children 2 days to 15 years old with no known bone marrow abnormalities were divided into four age groups. The signal intensity and homogeneity of the marrow in the proximal epiphysis, proximal metaphysis, diaphysis, distal metaphysis, distal epiphysis, and greater trochanter were compared with the signal intensity and homogeneity of surrounding muscle and fat and graded by two observers. In select cases, region-of-interest measurements of marrow, subcutaneous fat, and muscle were obtained to validate the visual grading system. RESULTS: Conversion of hematopoietic to fatty marrow in the femur followed a well-defined sequence, occurring first in the proximal and distal epiphyses, followed by the diaphysis, distal metaphysis, and then the proximal metaphysis. Although high-signal-intensity fatty marrow could be seen within the femoral diaphysis as early as 3 months of age, fatty marrow with various degrees of heterogeneity was routinely seen in this region by 12 months of age. After 5 years of age, the femoral diaphysis showed homogeneous high signal intensity. These findings are in contrast to previously published data that describe homogeneous red marrow within the femoral diaphysis during the first year of life and homogeneous yellow marrow visualized by 10 years of age. CONCLUSION: The normal age-related sequence of femoral marrow conversion we saw on MR images conforms to the sequence described in previously published reports, but this transformation, particularly in the diaphysis, occurs significantly earlier in life than has been previously reported. This discrepancy might be explained partially by the sensitivity of signal intensity in the femoral marrow to alterations in window and level settings.

Characterization of an activated human ros gene.

A human oncogene, mcf3, previously detected by a combination of DNA-mediated gene transfer and a tumorigenicity assay, derives from a human homology of the avian v-ros oncogene. Both v-ros and mcf3 can encode a protein with homology to tyrosine-specific protein kinases, and both mcf3 and v-ros encode a potential transmembrane domain N terminal to the kinase domain. mcf3 probably arose during gene transfer from a normal human ros gene by the loss of a putative extracellular domain. There do not appear to be any other gross rearrangements in the structure of mcf3.

Isolation and characterization of a new cellular oncogene encoding a protein with multiple potential transmembrane domains.

We have cloned and sequenced a new human oncogene and have named it mas. This oncogene was detected by its tumorigenicity in nude mice using the cotransfection and tumorigenicity assay previously described. The mas oncogene has a weak focus-inducing activity in transfected NIH 3T3 cells. A DNA rearrangement in the 5' noncoding sequence, which occurred during transfection, is probably responsible for activation of the mas gene. The cDNA sequence of the mas oncogene reveals a long open reading frame that codes for a 325 amino acid protein. This protein is very hydrophobic and has seven potential transmembrane domains. In this respect, the structure of the mas protein is novel among cellular oncogene products and may reflect a new functional class of oncogenes.

A DNA fragment hybridizing to a nif probe in Rhodobacter capsulatus is homologous to a 16S rRNA gene.

We have sequenced the Rhodobacter capsulatus nifH and nifD genes. The nifH gene, which codes for the dinitrogenase reductase protein, is 894 bp long and codes for a polypeptide of predicted Mr 32,412. The nifD gene, which codes for the alpha subunit of dinitrogenase, is 1,500 bp long and codes for a protein of predicted Mr 56,113. A 776-bp BglII-XhoI fragment containing only nif sequences was used as a hybridization probe against R. capsulatus genomic DNA. Two HindIII fragments, 11.8 kb and 4.7 kb in length, hybridize to this probe. Both fragments have been cloned from a cosmid library. The 11.8-kb fragment contains the nifH, D and K genes, as previously demonstrated (Scolnik and Haselkorn, 1984). In this paper we present evidence that suggests that the 4.7-kb HindIII fragment contains a gene coding for 16S rRNA, and that although homology between nif and this fragment can be observed in filter hybridization experiments, a second copy of the nif structural genes seems not to be present in this region.