Whole body PET/CT in the follow-up of asymptomatic patients with stage IIB-IIIB cutaneous melanoma. Acta Oncol 2016;55:1355-1359. [PMID: 27553064 DOI: 10.1080/0284186x.2016.1213879]

BACKGROUND

Whole body positron emission tomography (PET)/computed tomography (CT) is a sensitive imaging technique in patients with metastatic melanoma, but its role in the follow-up of asymptomatic high-risk patients is unclear. The aim was to study the role of PET/CT as a routine surveillance imaging tool in asymptomatic high-risk patients at the early stage of follow-up combined with a sufficient follow-up over several years.

MATERIAL AND METHODS

A total of 110 asymptomatic patients with clinically local American Joint Committee on Cancer (AJCC) stage IIB-IIIB melanoma underwent routine whole body PET/CT scanning after a mean interval of seven months after initial surgery. Clinical data were retrospectively analyzed after a median follow-up time of 4.6 years.

RESULTS

Recurrent melanoma was detected in 45 patients (41%) and 36 (33%) died of melanoma. In 11 asymptomatic patients (10%) occult disease was detected with a single PET/CT. In seven of these patients (64%), positive PET/CT finding had major influence in treatment decisions. Four patients underwent surgical metastasectomy and two of them remained disease-free. In 34 patients (31%) PET/CT revealed no disease, but recurrence was detected at a median time of 19 months after negative PET/CT scan. In 50 patients (45%) PET/CT finding was true negative. In 15 patients (14%) scan was false positive leading to additional management or repetitive imagings.

CONCLUSION

A single PET/CT could detect 24% of all recurrences in asymptomatic melanoma patients at the early stage of follow-up, but an earlier detection of occult metastases did not improve survival.

Tendon Graft Healing in Multiligament Reconstructed Knee Detected by FDG-PET/CT: A Pilot Study

Background and Aims:

The detection of graft viability is challenging in the multiligament reconstructed knee. Magnetic resonance imaging gives structural information but lacks the capability to assess biological activity of the grafts. 18F-labeled fluorodeoxyglucose positron emission tomography combined with computer tomography is shown to be a sensitive method for imaging tissue metabolism and viability. The aim of the present study was to evaluate the feasibility of fluorodeoxyglucose positron emission tomography combined with computer tomography imaging in the detection of the replacement graft metabolism in multiligament reconstructed knees.

Materials and Methods:

Seven patients (17–44 years) with multiligament reconstructed knee underwent fluorodeoxyglucose positron emission tomography combined with computer tomography to evaluate the biological activity of replacement grafts. The degree of fluorodeoxyglucose uptake reported as standard uptake values from the region of interest was analyzed 3–24 months postoperatively.

Results:

In all patients, the fluorodeoxyglucose positron emission tomography combined with computer tomography showed increased fluorodeoxyglucose uptake in all replacement grafts at different follow-up time points. Furthermore, fluorodeoxyglucose was higher at femoral condyles of operated knees compared to contralateral reference values.

Conclusion:

This pilot study shows a significant increase in tendon graft metabolism during two first years of postoperative healing. The fluorodeoxyglucose positron emission tomography combined with computer tomography imaging seems to be adequate method of assessment of graft metabolism and viability during postoperative healing. The clinical value of fluorodeoxyglucose positron emission tomography combined with computer tomography imaging, however, warrants further evaluation with longitudinal studies with a larger patient population.

Depressive symptoms, self-esteem, HIV symptom management self-efficacy and self-compassion in people living with HIV

The aims of this study were to examine differences in self-schemas between persons living with HIV/AIDS with and without depressive symptoms, and the degree to which these self-schemas predict depressive symptoms in this population. Self-schemas are beliefs about oneself and include self-esteem, HIV symptom management self-efficacy, and self-compassion. Beck's cognitive theory of depression guided the analysis of data from a sample of 1766 PLHIV from the USA and Puerto Rico. Sixty-five percent of the sample reported depressive symptoms. These symptoms were significantly (p ≤ 0.05), negatively correlated with age (r = -0.154), education (r = -0.106), work status (r = -0.132), income adequacy (r = -0.204, self-esteem (r = -0.617), HIV symptom self-efficacy (r = - 0.408), and self-kindness (r = - 0.284); they were significantly, positively correlated with gender (female/transgender) (r = 0.061), white or Hispanic race/ethnicity (r = 0.047) and self-judgment (r = 0.600). Fifty-one percent of the variance (F = 177.530 (df = 1524); p < 0.001) in depressive symptoms was predicted by the combination of age, education, work status, income adequacy, self-esteem, HIV symptom self-efficacy, and self-judgment. The strongest predictor of depressive symptoms was self-judgment. Results lend support to Beck's theory that those with negative self-schemas are more vulnerable to depression and suggest that clinicians should evaluate PLHIV for negative self-schemas. Tailored interventions for the treatment of depressive symptoms in PLHIV should be tested and future studies should evaluate whether alterations in negative self-schemas are the mechanism of action of these interventions and establish causality in the treatment of depressive symptoms in PLHIV.

A multinational study of self-compassion and human immunodeficiency virus-related anxiety

AIM

This study represents an initial effort at examining the association between the construct of self-compassion and human immunodeficiency virus (HIV)-related anxiety in a multinational population with HIV disease.

BACKGROUND

Previous studies have found that self-compassion is a powerful predictor of mental health, demonstrating positive and consistent linkages with various measures of affect, psychopathology and well-being, including anxiety.

METHODS

Cross-sectional data from a multinational study conducted by the members of the International Nursing Network for HIV Research (n = 1986) were used. The diverse sample included participants from Canada, China, Namibia, the United States of America and the territory of Puerto Rico. Study measures included the anxiety subscale of the Symptom Checklist-90 instrument, the Brief Version Self-Compassion Inventory and a single item on anxiety from the Revised Sign and Symptom Checklist.

FINDINGS

Study findings show that anxiety was significantly and inversely related to self-compassion across participants in all countries. We examined gender differences in self-compassion and anxiety, controlling for country. Levels of anxiety remained significantly and inversely related to self-compassion for both males (P = 0.000) and females (P = 0.000). Levels of self-compassion and anxiety varied across countries.

CONCLUSIONS

Self-compassion is a robust construct with cross-cultural relevance. A culturally based brief treatment approach aimed at increasing self-compassion may lend itself to the development of a cost effective adjunct treatment in HIV disease, including the management of anxiety symptoms.

Mediators of antiretroviral adherence: a multisite international study

The purpose of this study was to investigate the effects of stressful life events (SLE) on medication adherence (3 days, 30 days) as mediated by sense of coherence (SOC), self-compassion (SCS), and engagement with the healthcare provider (eHCP) and whether this differed by international site. Data were obtained from a cross-sectional sample of 2082 HIV positive adults between September 2009 and January 2011 from sites in Canada, China, Namibia, Puerto Rico, Thailand, and US. Statistical tests to explore the effects of stressful life events on antiretroviral medication adherence included descriptive statistics, multivariate analysis of variance, analysis of variance with Bonferroni post-hoc analysis, and path analysis. An examination by international site of the relationships between SLE, SCS, SOC, and eHCP with adherence (3 days and 30 days) indicated these combined variables were related to adherence whether 3 days or 30 days to different degrees at the various sites. SLE, SCS, SOC, and eHCP were significant predictors of adherence past 3 days for the United States (p = < 0.001), Canada (p = 0.006), and Namibia (p = 0.019). The combined independent variables were significant predictors of adherence past 30 days only in the United States and Canada. Engagement with the provider was a significant correlate for antiretroviral adherence in most, but not all, of these countries. Thus, the importance of eHCP cannot be overstated. Nonetheless, our findings need to be accompanied by the caveat that research on variables of interest, while enriched by a sample obtained from international sites, may not have the same relationships in each country.

Hypoglycemia detection based on cardiac repolarization features

Hypoglycemia is known to affect repolarization characteristics of the heart. These changes are shown from ECG by prolonged QT-time and T-wave flattening. In this study we constructed a classifier based on these ECG parameters. By using the classifier we tried to detect hypoglycemic events from measurements of 22 test subjects. Hypoglycemic state was achieved using glucose clamp technique. Used test protocol consisted of three stages: normoglycemic period, transition period (blood glucose concentration decreasing) and hypoglycemic period. Subjects were divided into three groups: 9 healthy controls (Healthy), 6 otherwise healthy type 1 diabetics (T1DM) and 7 type 1 diabetics with disease complications (T1DMc). Detection of hypoglycemic event could be made passably from 15/22 measurements. In addition, we found that detection process is easier for healthy and T1DM groups than T1DMc group diabetics because in T1DMc group subjects' have lower autonomic response to hypoglycemic events. Also we noticed that changes in ECG occurs few minutes after blood glucose is decreased below 3.5 mmol/1.

Dynamic estimation of cardiac repolarization characteristics during hypoglycemia in healthy and diabetic subjects

Hypoglycemia is known to affect the repolarization characteristics of the heart, but the mechanisms behind these changes are not completely understood. We analyzed repolarization characteristics continuously from 22 subjects during normoglycemic period, transition period (blood glucose concentration decreasing) and hypoglycemic period from nine healthy controls (Healthy), six otherwise healthy type 1 diabetics (T1DM) and seven type 1 diabetics with disease complications (T1DMc). An advanced principal component regression (PCR)-based method was used for estimating ECG parameters beat-by-beat, and thus, continuous comparison between the repolarization characteristics and blood glucose values was made. We observed that hypoglycemia related ECG changes in the T1DMc group were smaller than changes in the Healthy and T1DM groups. We also noticed that when glucose concentration remained at a low level, the heart rate corrected QT interval prolonged progressively. Finally, a few minutes time lag was observed between the start of hypoglycemia and cardiac repolarization changes. One explanation for these observations could be that hypoglycemia related hormonal changes have a significant role behind the repolarization changes. This could explain at least the observed time lag (hormonal changes are slow) and the lower repolarization changes in the T1DMc group (hormonal secretion lowered in long duration diabetics).

In vivo measurements of glucose uptake in human Achilles tendon during different exercise intensities

Muscular contraction and loading of adjacent tendons has been demonstrated to cause increased blood flow and metabolic activity in the peritendinous region. However, it is poorly known to what extent the human tendon itself takes up glucose during exercise. Thus, the purpose of this study was to measure tendon glucose uptake with increasing exercise intensity and to compare it to muscle glucose uptake at the same intensities. Eight young men were examined on three separate days during which they performed 35 min of cycling at 30, 55 and 75 % of VO2max, respectively. Glucose uptake was measured directly by positron emission tomography (PET) with 2-[ (18)F]fluoro-2-deoxyglucose ([18F]FDG). [18F]FDG was injected after 10 min of exercise that was continued for a further 25 min after the injection. PET scanning of the thigh and Achilles region was performed after the exercise. Glucose uptake of the Achilles tendon (AT) remained unchanged (7.1 +/- 1.5, 6.6 +/- 1.1, and 6.0 +/- 1.1 micromol.kg(-1).min(-1)) with the increasing workload, although the glucose uptake in m. quadriceps femoris simultaneously clearly increased (48 +/- 35, 120 +/- 35, and 152 +/- 74 micromol.kg(-1).min(-1), p < 0.05). In conclusion, the AT takes up glucose during exercise but in significantly smaller amounts than the skeletal muscle does. Furthermore, glucose uptake in the AT is not increased with the increasing exercise intensity. This may be partly explained by the cycle ergometry exercise used in the present study, which probably causes only a little increase in strain to the AT with increasing exercise intensity.

Muscle blood flow and flow heterogeneity during exercise studied with positron emission tomography in humans

Blood flow is the main regulator of skeletal muscle's oxygen supply, and several studies have shown heterogeneous blood flow among and within muscles. However, it remains unclear whether exercise changes the heterogeneity of flow in exercising human skeletal muscle. Muscle blood flow and spatial flow heterogeneity were measured simultaneously in exercising and in the contralateral resting quadriceps femoris (QF) muscle in eight healthy men using H2(15)O and positron emission tomography. The relative dispersion (standard deviation/mean) of blood flow was calculated as an index of spatial flow heterogeneity. Average muscle blood flow in QF was 29 (10) ml x (kg muscle)(-1) x min(-1) at rest and 146 (54) ml x (kg muscle)(-1) x min(-1) during exercise (P = 0.008 for the difference). Blood flow was significantly (P < 0.001) higher in the vastus medialis and the vastus intermedius than in the vastus lateralis and the rectus femoris, both in the resting and the exercising legs. Flow was more homogeneous in the exercising vastus medialis and more heterogeneous (P < 0.001) in the exercising vastus lateralis (P = 0.01) than in the resting contralateral muscle. Flow was more homogeneous (P < 0.001) in those exercising muscles in which flow was highest (vastus intermedius and vastus medialis) as compared to muscles with the lowest flow (vastus lateralis and the rectus femoris). These data demonstrate that muscle blood flow varies among different muscles in humans both at rest and during exercise. Muscle perfusion is spatially heterogeneous at rest and during exercise, but responses to exercise are different depending on the muscle.

Enhanced stimulation of glucose uptake by insulin increases exercise-stimulated glucose uptake in skeletal muscle in humans: studies using [15O]O2, [15O]H2O, [18F]fluoro-deoxy-glucose, and positron emission tomography

In vitro studies have shown that insulin and exercise stimulate glucose uptake in part via distinct mechanisms. We determined whether a high rate of insulin-stimulated glucose uptake (good insulin sensitivity) is associated with an enhanced ability of exercise to increase glucose uptake in vivo in humans. In our study, 22 normal subjects performed one-legged isometric exercise for 105 min (45-150 min) under intravenously maintained euglycemic-hyperinsulinemic conditions (0-150 min). Rates of oxygen consumption, blood flow, and glucose uptake were quantitated simultaneously in skeletal muscle of both legs using [15O]O2, [15O]H2O, [18F]fluoro-deoxy-glucose, and positron emission tomography. The one-legged exercise, performed at an intensity of 11% of maximal isometric force, was designed to induce similar increases in oxygen consumption in both groups. In the entire group, exercise increased oxygen consumption from 2.3 +/- 0.3 ml x kg(-1) muscle x min(-1) (insulin) to 34.2 +/- 3. ml x kg(-1) muscle x min(-1) (insulin and exercise) (P < 0.001) and muscle glucose uptake from 60 +/- 6 pmol x kg(-1) muscle x min(-1) (insulin) to 220 +/- 22 micromol x kg(-1) muscle x min(-1) (insulin and exercise) (P < 0.001). The exercise-induced increase in glucose uptake was due to marked increases in blood flow (36 +/- 5 ml x kg(-1) muscle x min(-1) [insulin] vs. 262 +/- 20 ml x kg(-1) muscle x min(-1) [insulin and exercise], P < 0.001) rather than glucose extraction, which decreased from 2.0 +/- 0.2 mmol/l (insulin) to 1.0 +/- 0.1 mmol/1 (insulin and exercise) (P < 0.001). The subjects were classified according to their mean rate of whole-body insulin-stimulated glucose uptake into those with high (49 +/- 3 micromol x kg(-1) x min(-1)) and normal (27 +/- 2 micromol x kg(-1) x min(-1)) rates of insulin-stimulated glucose uptake. Both insulin-stimulated (2.4 +/- 1.1 vs. 2.3 +/- 1.2 ml x kg(-1) muscle x min(-1), normal vs. high insulin sensitivity) and exercise- and insulin-stimulated (33 +/- 6 vs. 34 +/- 4 ml x kg(-1) muscle x min(-1)) rates of oxygen consumption were comparable between the groups. Exercise increased glucose uptake more in the group with high insulin sensitivity (195 +/- 25 pmol x kg(-1) muscle x min(-1)) than in the group with normal insulin sensitivity (125 +/- 19 micromol x kg(-1) muscle x min(-1)) (P < 0.05). Muscle blood flow was closely correlated with the rate of oxygen consumption (r = 0.91, P < 0.0001), and insulin-stimulated (30 +/- 5 vs. 35 +/- 6 ml x kg(-1) muscle x min(-1)) and exercise-induced increments (222 +/- 31 vs. 228 +/- 23 ml x kg(-1) muscle x min(-1)) in muscle blood flow were similar between the groups. Glucose extraction remained higher in the group with high insulin sensitivity (1.2 +/- 0.2 mmol/l) than in the group with normal insulin sensitivity (0.7 +/- 0.1 mmol/l, P < 0.05). We conclude that whereas acute exercise per se increases glucose uptake via increasing glucose delivery, good insulin sensitivity modulates exercise-induced increases in glucose uptake by enhancing cellular glucose extraction.

Sodium nitroprusside increases human skeletal muscle blood flow, but does not change flow distribution or glucose uptake

1. The role of blood flow as a determinant of skeletal muscle glucose uptake is at present controversial and results of previous studies are confounded by possible direct effects of vasoactive agents on glucose uptake. Since increase in muscle blood flow can be due to increased flow velocity or recruitment of new capillaries, or both, it would be ideal to determine whether the vasoactive agent affects flow distribution or only increases the mean flow. 2. In the present study blood flow, flow distribution and glucose uptake were measured simultaneously in both legs of 10 healthy men (aged 29 +/- 1 years, body mass index 24 +/- 1 kg m-2) using positron emission tomography (PET) combined with [15O]H2O and [18F]fluoro-2-deoxy-D-glucose (FDG). The role of blood flow in muscle glucose uptake was studied by increasing blood flow in one leg with sodium nitroprusside (SNP) and measuring glucose uptake simultaneously in both legs during euglycaemic hyperinsulinaemia (insulin infusion 6 pmol kg-1 min-1). 3. SNP infusion increased skeletal muscle blood flow by 86 % (P < 0.01), but skeletal muscle flow distribution and insulin-stimulated glucose uptake (61.4 +/- 7. 5 vs. 67.0 +/- 7.5 micromol kg-1 min-1, control vs. SNP infused leg, not significant), as well as flow distribution between different tissues of the femoral region, remained unchanged. The effect of SNP infusion on blood flow and distribution were unchanged during infusion of physiological levels of insulin (duration, 150 min). 4. Despite a significant increase in mean blood flow induced by an intra-arterial infusion of SNP, glucose uptake and flow distribution remained unchanged in resting muscles of healthy subjects. These findings suggest that SNP, an endothelium-independent vasodilator, increases non-nutritive, but not nutritive flow or capillary recruitment.

Nurses' Willingness to Perform AIDS Patient Care

We evaluated nurses from hospitals with different prevalences of AIDS patients and with different levels of nursing education to measure their willingness to provide care to AIDS patients. Nurses who were most experienced in AIDS patient care, employed in high-prevalence hospitals, and who considered themselves most knowledgeable about infectious disease consistently were less willing to provide nursing care for AIDS patients. Nurses with BSN or MSN education employed in hospitals with low and moderate prevalence of AIDS were the most willing to provide AIDS patient care. The results are discussed in light of recent research on universal precautions adherence and factors that may contribute to increasingly negative attitudes for nurses who provide sustained AIDS patient care.