Neurovascular and hemodynamic responses to mental stress and exercise in severe COVID-19 survivors

Previous studies show that COVID-19 survivors have elevated muscle sympathetic nerve activity (MSNA), endothelial dysfunction, and aortic stiffening. However, the neurovascular responses to mental stress and exercise are still unexplored. We hypothesized that COVID-19 survivors, compared with age- and body mass index (BMI)-matched control subjects, exhibit abnormal neurovascular responses to mental stress and physical exercise. Fifteen severe COVID-19 survivors (aged: 49 ± 2 yr, BMI: 30 ± 1 kg/m2) and 15 well-matched control subjects (aged: 46 ± 3 yr, BMI: 29 ± 1 kg/m2) were studied. MSNA (microneurography), forearm blood flow (FBF), and forearm vascular conductance (FVC, venous occlusion plethysmography), mean arterial pressure (MAP, Finometer), and heart rate (HR, ECG) were measured during a 3-min mental stress (Stroop Color-Word Test) and during a 3-min isometric handgrip exercise (30% of maximal voluntary contraction). During mental stress, MSNA (frequency and incidence) responses were higher in COVID-19 survivors than in controls (P < 0.001), and FBF and FVC responses were attenuated (P < 0.05). MAP was similar between the groups (P > 0.05). In contrast, the MSNA (frequency and incidence) and FBF and FVC responses to handgrip exercise were similar between the groups (P > 0.05). MAP was lower in COVID-19 survivors (P < 0.05). COVID-19 survivors exhibit an exaggerated MSNA and blunted vasodilatory response to mental challenge compared with healthy adults. However, the neurovascular response to handgrip exercise is preserved in COVID-19 survivors. Overall, the abnormal neurovascular control in response to mental stress suggests that COVID-19 survivors may have an increased risk to cardiovascular events during mental challenge.

Interleukin-11 attenuates ifosfamide-induced hemorrhagic cystitis

OBJECTIVE

To investigate the possible protective effect of recombinant human interleukin-11 (rhIL-11) against ifosfamide (IFS)-induced hemorrhagic cystitis (HC).

MATERIALS AND METHODS

Male Swiss mice (20-30g) were pretreated with rhIL-11 (25-625 mg, subcutaneously.) 30 min before intraperitoneal injection of IFS (400 mg/kg) or with saline (control group). Twelve hours later, HC was evaluated by bladder wet weight (BWW) to quantify edema, Evans blue extravasation (EBE) to measure vascular permeability, and macroscopic and microscopic analysis. All bladders were assessed by histopathological analysis.

RESULTS

rhIL-11 (at 125 and 625 mg) attenuated the IFS- induced increase of BWW (37.48% and 45.44%, respectively, p < 0.05) and EBE (62.35% and 56.47%, respectively, p < 0.05). IFS- induced macroscopic edema and hemorrhage and microscopic alterations, were also prevented by rhIL-11 at 625 microg. (p < 0.05).

CONCLUSION

Our results demonstrate a protective effect of rhIL-11 on experimental IFS- induced HC, not previously reported.

Ultrasonic growth parameters in fetuses of mothers with primary addiction to cocaine

Sixty-seven women with primary addiction to cocaine were evaluated during their pregnancies by multiple ultrasound studies. Ultrasonic parameters included biparietal diameter, femur length, abdominal circumference, and head circumference. These values were compared with ultrasonic growth parameters in nonaddicted fetuses. Head and abdominal circumference data were used to evaluate the fetuses according to growth pattern. With this system of scoring, subtleties of asymmetric versus symmetric intrauterine growth retardation become apparent. In addition, birth weights of addicted infants were compared with birth weights of nonaddicted infants. The results suggest that, although statistically significant differences in birth weights cannot be demonstrated, abnormal growth of the addicted fetuses does occur. Addicted fetuses show a greater proportion of biparietal diameter and abdominal circumference values below the 50th and 25th percentiles than nonaddicted fetuses, and addicted fetuses more frequently exhibit intrauterine growth retardation patterns. These data suggest that it is fruitful to study these infants with near-normal size but with abnormal intrauterine growth patterns.