Renal artery dissection as an overuse Injury

The diagnosis of renal infarction is often convoluted due to its non-specific presentation. It can mimic disease processes as disparate as pyelonephritis, diverticulitis, or nephrolithiasis. This case is further complicated by the presence of a pelvic kidney with triplicate arterial input. It is difficult to estimate the incidence of pelvic kidneys as the numerous sources vary wildly in their estimations; however, the paucity information, in and of itself, speaks to the rarity of the condition. In this case, a 58-year-old male presents to the emergency department after experiencing sharp, sudden, and severe groin pain while swinging a golf club. The patient was noted to have an abnormally high systolic blood pressure in the 170s and hematuria, but all other initial labs and assessments were unremarkable. An initial computed tomography scan with intravenous contrast of the abdomen and pelvis showed partial necrosis of a pelvic kidney. Follow-up computed tomography angiography revealed that a dissection in one of the arteries supplying the kidney created an infarction and resultant necrosis. Vessel size, location and time between injury and diagnosis made endovascular intervention impractical. The patient was started on aspirin and Plavix, observed for 3 days and sent home.

Relative influence of age, resting heart rate and sedentary life style in short-term analysis of heart rate variability

In order to assess the relative influence of age, resting heart rate (HR) and sedentary life style, heart rate variability (HRV) was studied in two different groups. The young group (YG) consisted of 9 sedentary subjects aged 15 to 20 years (YG-S) and of 9 nonsedentary volunteers (YG-NS) also aged 15 to 20. The elderly sedentary group (ESG) consisted of 16 sedentary subjects aged 39 to 82 years. HRV was assessed using a short-term procedure (5 min). R-R variability was calculated in the time-domain by means of the root mean square successive differences. Frequency-domain HRV was evaluated by power spectrum analysis considering high frequency and low frequency bands. In the YG the effort tolerance was ranked in a bicycle stress test. HR was similar for both groups while ESG showed a reduced HRV compared with YG. Within each group, HRV displayed a negative correlation with HR. Although YG-NS had better effort tolerance than YG-S, their HR and HRV were not significantly different. We conclude that HRV is reduced with increasing HR or age, regardless of life style. The results obtained in our short-term study agree with others of longer duration by showing that age and HR are the main determinants of HRV. Our results do not support the idea that changes in HRV are related to regular physical activity.

Right ventricle systolic pressure increase following intravenous acetylcholine injection

In order to characterize and compare right ventricle (RV) and left ventricle (LV) and left ventricle (LV) hemodynamic responses to physiological and pharmacological maneuvers, we studied the effect of the intravenous injection of acetylcholine (ACh) in 32 anaesthetized mongrel dogs. After producing a decrease in aortic pressure and in left ventricle systolic pressure (LVSP). ACh always determined a significant increase in the right ventricle systolic pressure (RVSP) preceded or not by a fall in this parameter. Atropine and denervation of carotid and aortic pressure receptors suppressed this rise in RVSP. It is suggested that the RVSP increase is secondary to a sympathetic reflex response parting from the pressure receptors after detecting the aortic hypotension elicited by ACh following peripheral vascular bed vasodilation. Sympathetic discharge could produce a systemic venoconstriction that increases the venous return to the RV, together with a direct inotropic effect on the ventricular muscle. Both actions, peripheral and myocardial, would account for the RVSP increase. We cannot totally disconsider a probable additional pulmonary vasoconstrictor effect included as part of the sympathetic reflex response.

Follicle-stimulating hormone induction of steel factor (SLF) mRNA in mouse Sertoli cells and stimulation of DNA synthesis in spermatogonia by soluble SLF

Follicle-stimulating hormone (FSH) and its intracellular mediator, cAMP, increase the mRNA levels for the Steel factor (SLF, the c-kit ligand) in cultured primary mouse Sertoli cells. The inductive effect of cAMP is more evident in cultures from 13-day-old animals than in cultures from 18-day-old animals. Analysis through the polymerase chain reaction (PCR) indicates that (Bu)2cAMP or FSH treatment increases the levels of the mRNAs for both the potentially soluble form and the transmembrane form of SLF in cultured Sertoli cells. The ratio between mRNAs encoding the potentially soluble form and the transmembrane form of SLF increases during postnatal testis development, and it is higher in cultured Sertoli cells with respect to total testis, suggesting that, under the in vitro conditions, SLF could be produced by Sertoli cells mainly as a soluble factor. Soluble recombinant SLF stimulates, in a dose-dependent fashion, thymidine incorporation in cultures of isolated germ cell populations enriched in the mitotic stages (spermatogonia), independently of the presence of serum, whereas cAMP analogs have no effect. Autoradiographic analysis shows that SLF selectively stimulates DNA synthesis in type A spermatogonia.