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The transfer of intact mitochondria between heterogeneous cell types has been confirmed in various settings, including cancer. However, the functional implications of mitochondria transfer on tumor biology are poorly understood. Here we show that mitochondria transfer is a prevalent phenomenon in glioblastoma (GBM), the most frequent and malignant primary brain tumor. We identified horizontal mitochondria transfer from astrocytes as a mechanism that enhances tumorigenesis in GBM. This transfer is dependent on network-forming intercellular connections between GBM cells and astrocytes, which are facilitated by growth-associated protein 43 (GAP43), a protein involved in neuron axon regeneration and astrocyte reactivity. The acquisition of astrocyte mitochondria drives an increase in mitochondrial respiration and upregulation of metabolic pathways linked to proliferation and tumorigenicity. Functionally, uptake of astrocyte mitochondria promotes cell cycle progression to proliferative G2/M phases and enhances self-renewal and tumorigenicity of GBM. Collectively, our findings reveal a host-tumor interaction that drives proliferation and self-renewal of cancer cells, providing opportunities for therapeutic development., (© 2023. The Author(s).)

A 76-year-old woman presented after 1 day of melena and anemia. A Meckel's scan revealed an upper mid abdominal focus of activity that paralleled stomach activity. Later, the surgeon removed the corresponding lesion in the mid ilium. Pathology confirmed that the lesion was a carcinoid tumor, not ectopic gastric mucosa. The false-positive Meckel's scan had revealed the true source of gastrointestinal bleeding and an unsuspected solitary carcinoid tumor. This is the third published case of a carcinoid tumor discovered by a false-positive Meckel's scan.

Classically, the "rim sign" has been described throughout the hepatobiliary scan. The authors present a case of a late rim sign visualized at 25 minutes postinjection that proved to be acute upon chronic acalculous cholecystitis without gangrene.

To determine whether there is a correlation between aortic root size and the prevalence of aortic regurgitation, we performed color flow Doppler echocardiographic studies on 1015 consecutive patients during a 3-month period. Patients were grouped according to their M-mode aortic root diameter as measured in the left parasternal position. The measured groups ranged from 2.0 to 4.5 cm, grouped at 0.1 cm intervals. As the aortic root size enlarged, the prevalence of aortic regurgitation increased linearly (p less than 0.001; correlation coefficient, r = 0.75). At an aortic root size in the "small normal" range of 2.0 to 2.4 cm, the prevalence of aortic regurgitation was 0% to 15%. In the "intermediate" and "top normal" ranges of 2.9 to 3.7 cm, the prevalence of aortic regurgitation increased linearly from 15% to 47%. With aortic root dilation, the prevalence of aortic root regurgitation was generally more than 50%. The severity of aortic regurgitation was semiquantified. Aortic root size was not a good indicator for the severity of aortic regurgitation. Patients with moderate and severe aortic regurgitation had variable aortic root sizes. Throughout the range of aortic root sizes, mild aortic regurgitation predominated. We conclude that aortic regurgitation is a common finding in patients with aortic roots that are dilated or are in the "top normal" size range, that the prevalence of aortic regurgitation increases linearly with aortic root size, and that aortic root size does not correlate with the severity of aortic regurgitation.

In brief: Plantar fasciitis and heel spurs are two contributing causes of heel spur syndrome and sometimes cannot be differentiated from one another. In any case, the syndrome is caused by trauma to the heel and is often accompanied by severe pain. Treatment methods include rest, anti-inflammatory medication, and various types of shoe padding. Cortisone may be injected into the heel if symptoms continue, and surgery may be necessary if conservative treatment is unsuccessful.

Detection and localization of peripheral arterial disease was evaluated by intravenous injection of 201Tl at peak exercise in 22 subjects. Images of the gluteals (G), thighs (T), knees (K), and calves (C) were obtained at exercise and after a 3 hr delay, and stored in a computer, interextremity (T/T and C/C) and intraextremity (G/T, T/C, T/K) counts ratios were calculated. Normal values were defined in 11 control subjects and compared with those obtained in 11 patients with angiographically proven peripheral arterial disease. Bilateral disease was detected scintigraphically in all patients. T/T and G/T ratios correctly predicted proximal disease in nine of 12 limbs, while C/C, T/C, T/K ratios correctly predicted distal disease in 21 of 21 involved limbs. Delay images 3 hr after stress generally reverted towards the norm. Objective systematic evaluation of limb isotope uptake permits accurate detection and localization of peripheral arterial disease. Method accuracy compares favorably with physical signs and with other noninvasive methods of detection of peripheral vascular disease. Scintigraphy presents advantages which indicate great clinical potential.