Superficial- and deep-tissue temperature increases in anesthetized dogs during exposure to high specific absorption rates in a 1.5-T MR imager

Superficial- and deep-tissue heating was measured in five dogs during high-specific-absorption-rate radiofrequency (RF) irradiation to see whether significant temperature changes could be produced by a 1.5-T clinical magnetic resonance imager. The RF power output employed was 6.3 times that required for routine imaging. Temperature probes were placed in both deep and superficial tissues, and temperatures were recorded before, during, and after exposure. In each dog, there was a linear temperature increase of several degrees during RF exposure; the maximal average change was 4.6 degrees C in the urinary bladder. The temperature increase was slightly greater in deep tissues than in superficial tissues. The calculated specific absorption rate, based on the temperature change, averaged 7.9 W/kg for all five dogs. These findings argue for continued caution in the design and operation of imagers capable of high specific absorption rates, particularly when they are used for imaging infants or patients with altered thermoregulatory capability.     

Amniotic fluid acetylcholinesterase activity and alpha-fetoprotein in chromosomal anomalies and neural tube defects

Measurement of alpha-fetoprotein concentration and acetylcholinesterase activity in amniotic fluid can be used to identify chromosomal defects as well as neural tube defects. In seven cases of trisomy 21 and one case of partial trisomy 3, alpha-fetoprotein concentrations were below the reference range but values for acetylcholinesterase activity were normal for the appropriate gestational age. One case of trisomy 13 had an increase in acetylcholinesterase activity and normal alpha-fetoprotein concentration.     

Cyclic GMP in urine to monitor the response to ovarian cancer to therapy

Guanosine 3':5'-phosphate (cycle GMP) in urine has been used to monitor the response of patients with ovarian cancer to treatment. Changes in the cyclic GMP level appear to correlate well with clinical status in that the disappearance of clinically detectable tumour is associated with a drop in the level whereas a tumour recurrence is associated with an elevation. Serially measured cyclic GMP is valuable for detecting a recurrence of tumour growth in patients in clinical remission and can predate any clinical signs by as much as 10 months. In patients who show no response to treatment, cyclic GMP levels in urine are elevated in the majority of specimens collected.     

Enhancement of human erythroid progenitor cell growth by media conditioned by a human t-lymphocyte line

Recent studies have shown that soluble factors elaborated by human T lymphocytes enhance erythroid burst formation by human peripheral blood null cells. This study demonstrates that media conditioned by a long- term T lymphocyte line augmented the growth of erythroid colonies in vitro in the presence of erythropoietin (Ep). ATCC.CCl 119 (CCRF-CEM) was derived from a patient with ALL of T-lymphoblast origin. Cells from the stocks used in these experiments maintained T-cell characteristics as determined by histochemical and rosetting techniques. Increased numbers of 16 day BFU-E were seen when Ficoll-Hypaque separated peripheral blood leukocytes were cultured in the presence of a 10% (v/v) concentration of CCL 119 conditioned medium (CM). CM increased the number of BFU-E even when Ep or fetal calf serum were not growth limiting. CM also increased the number of late BFU-E observed in cultures of nonadherent bone marrow cells. When peripheral blood mononuclear cells were depleted of E-rosetting cells, only small numbers of BFU-E grew. Addition of 119 CM increased the numbers of BFU- E in E-rosette-depleted cultures. CM from B-cell, macrophage, or other T-cell lines tested did not stimulate BFU-E growth as consistently. These studies indicate that CM obtained from ATCC.CCL 119 cells contained burst-promoting activity, one of the factors required for proliferation of early erythroid progenitors.     

Risk factors for adult-onset asthma: A 14-year longitudinal study

Background and objectives:   Few longitudinal studies have examined the risk factors and natural history of adult-onset asthma. This study assessed the subject characteristics and lifestyle factors that predicted the new diagnosis of asthma in adulthood and how these factors changed over time in those who developed asthma compared with those who do not.
Methods:   The study enrolled 1554 adults from the Busselton Health Study seen in 1981 and again in 1994–1995 who initially reported never having had doctor-diagnosed asthma. Questionnaire measures were used to assess doctor-diagnosed asthma, respiratory history and tobacco smoking. Height, weight and spirometric measures of lung function were measured. Atopy was assessed by skin prick tests. Logistic regression analysis was used to identify risk factors for adult-onset asthma and changes over time.
Results:   Reported wheeze, rhinitis, chronic cough, smoking and lower levels of lung function in 1981 each predicted asthma diagnosis by 1994–1995. Neither initial skin-prick reactivity nor newly positive skin-prick tests at follow up were associated with adult-onset asthma. Those diagnosed with asthma were more likely to have new wheeze, new rhinitis, new habitual snoring, weight gain and excess decline in lung function.
Conclusions:   Adult-onset asthma has risk factors that are distinct from those observed in childhood asthma. The presence of upper airway symptoms including rhinitis, as well as lifestyle factors, such as smoking, predicts those at greatest risk. However, neither pre-existing atopy nor new atopy as measured by skin prick tests was associated with adult-onset asthma.     

Extracardiac <Superscript>18</Superscript>F-florbetapir imaging in patients with systemic amyloidosis: more than hearts and minds

Purpose

¹⁸F-Florbetapir has been reported to show cardiac uptake in patients with systemic light-chain amyloidosis (AL). This study systematically assessed uptake of ¹⁸F-florbetapir in patients with proven systemic amyloidosis at sites outside the heart.

Methods

Seventeen patients with proven cardiac amyloidosis underwent ¹⁸F-florbetapir PET/CT imaging, 15 with AL and 2 with transthyretin amyloidosis (ATTR). Three patients had repeat scans. All patients had protocolized assessment at the UK National Amyloidosis Centre including imaging with ¹²³I-serum amyloid P component (SAP). ¹⁸F-Florbetapir images were assessed for areas of increased tracer accumulation and time–uptake curves in terms of standardized uptake values (SUV_mean) were produced.

Results

All 17 patients showed ¹⁸F-florbetapir uptake at one or more extracardiac sites. Uptake was seen in the spleen in 6 patients (35%; 6 of 9, 67%, with splenic involvement on ¹²³I-SAP scintigraphy), in the fat in 11 (65%), in the tongue in 8 (47%), in the parotids in 8 (47%), in the masticatory muscles in 7 (41%), in the lungs in 3 (18%), and in the kidney in 2 (12%) on the late half-body images. The ¹⁸F-florbetapir spleen retention index (SRI) was calculated. SRI >0.045 had 100% sensitivity/sensitivity (in relation to ¹²³I-SAP splenic uptake, the current standard) in detecting splenic amyloid on dynamic imaging and a sensitivity of 66.7% and a specificity of 100% on the late half-body images. Intense lung uptake was seen in three patients, one of whom had lung interstitial infiltration suggestive of amyloid deposition on previous high-resolution CT. Repeat imaging showed a stable appearance in all three patients suggesting no early impact of treatment response.

Conclusion

¹⁸F-Florbetapir PET/CT is a promising tool for the detection of extracardiac sites of amyloid deposition. The combination of uptake in the heart and uptake in the spleen on ¹⁸F-florbetapir PET/CT, a hallmark of AL, suggests that this tracer holds promise as a screening tool for AL.