The suppression of endogenous adrenalin in the prolongation of ketamine anesthesia

This study investigated whether or not the anesthetic effect of ketamine in rats is dependent on adrenal gland hormones. The study was performed on two main rat groups, intact and adrenalectomized. Rat were divided into subgroups and given appropriate doses of ketamine, metyrapone or metyrosine. Durations of anesthesia in the groups were then recorded. Endogenous catecholamine levels were measured in samples taken from peripheral blood. This experimental results showed that ketamine did not induce anesthesia in intact rats at doses of 15 or 30 mg/kg, and that at 60 mg/kg anesthesia was established for only 11 min. However, ketamine induced significant anesthesia even at a dose of 30 mg/kg in animals in which production of endogenous catecholamine (adrenalin, noradrenalin dopamine) was inhibited with metyrosine at a level of 45–47%. Ketamine at 60 mg/kg in animals in which endogenous catecholamine was inhibited at a level of 45–47% established anesthesia for 47.6 min. However, ketamine at 30 and 60 mg/kg induced longer anesthesia in adrenalectomized rats with higher noradrenalin and dopamine levels but suppressed adrenalin production. Adrenalin plays an important role in the control of duration of ketamine anesthesia, while noradrenalin, dopamine and corticosterone have no such function. If endogenous adrenalin is suppressed, ketamine can even provide sufficient anesthesia at a 2-fold lower dose. This makes it possible for ketamine to be used in lengthy surgical procedures.     

Methenamine's journey of 160 years: Repurposal of an old urinary antiseptic for treatment and hypoxic radiosensitization of cancers and glioblastoma

Methenamine (hexamethylenetetramine, hexamine, urotropine) is a compound discovered in 1859, which is still currently being used as a urinary antiseptic. Methenamine is highly soluble in water and polar solvents, and its molecular constitution is similar to adamantane compounds with tetrahedral cage like structure. In acidic conditions, methenamine decomposes to formaldehyde and ammonia. Recently, methenamine has gained a renewal of interest due to antibiotic‐resistant bacteria urinary tract infections; interestingly, bacteria cannot gain resistance to formaldehyde. In 1968, David and Burkitt reported remarkable regression of four Burkitt Lymphoma patients in eight subjects who were treated with septicemine (a solution containing 6.3 g of methenamine iodomethylate and 1 g of methenamine sodium benzoate in 100 cc distilled water). Unfortunately, these striking observations did not gain interest in the medical community; despite experimental models that showed that methenamine synergized with hyperthermia, radiation, and chemotherapy to block cancer growth. As the hypoxic core of tumours have an acidic pH, it would be plausible to expect that methenamine would selectively target dormant, non‐proliferative, and treatment‐resistant cancer clones in large tumours. Moreover, previous data suggests that methenamine can be safely used intravenously and for treatment of infections of the central nervous system. It may therefore be an effective adjuvant in treatment of systemic cancers and glioblastoma.     

Does combining magnetic-activated cell sorting with density gradient or swim-up improve sperm selection?

Purpose

The present study aimed to evaluate whether combining the magnetic-activated cell sorting (MACS) with density-gradient (DG) or swim-up (SU) sperm separation techniques can improve sperm selection to obtain higher quality spermatozoa.

Methods

Two commonly used sperm selection techniques, SU and DG, were compared to MACS combined with either SU or DG. Spermatozoa obtained from normozoospermic (n?=?10) and oligozoospermic (n?=?10) cases were grouped as SU, DG, SU+MACS, and DG+MACS followed by the analysis of sperm morphology, motility, DNA integrity, and the levels of Izumo-1 and PLCZ proteins.

Results

Although spermatozoa obtained by SU or DG when combined with MACS have improved aspects when compared to SU or DG alone, results did not reach a statistically significant level. Moreover, separation with MACS caused a significant loss in the numbers of total and rapid progressive spermatozoa.

Conclusions

Considering the cost/benefit ratio, MACS application together with traditional techniques may only be preferred in certain cases having higher concentrations of spermatozoa, but it does not seem to be an ideal and practical sperm selection technique for routine use.

     

Ramification pattern of the thenar branch of the median nerve entering the thenar fascia and the distribution of the terminal branches in the thenar musculature: Anatomic cadaver study in 144 hands

Knowledge of the anatomy of the median nerve is important in surgery of the palmar aspect of the hand. The purpose of our study was to investigate the ramification pattern of the thenar branch before entering the thenar fascia and the distribution of the terminal branches in the thenar musculature. The observations were carried out on 144 hands of 74 dissecting room cadavers. According to the number of the thenar branches entering the thenar fascia we classified our specimens into four types. In 121 hands (84%, Group I) the thenar branch piercing the thenar fascia was a single trunk. In 19 hands (13.2%, Group II) two branches; in three (2.1%; Group III), three branches; and in one hand (0.7%; Group IV), four branches were identified entering the thenar fascia. Accessory thenar nerve was found in 8.3% of hands. The further division of each branch to its terminal branches was investigated in detail. Our results show that the more the number of thenar branches entering the thenar fascia, the less the terminal branching. Because more than one branch was seen in 16% of the specimens, meticulous dissection is required for preventing injury of the thenar branches before entering the thenar fascia.     

Anxiety but not depression is associated with elevated blood pressure in a community group of French elderly

OBJECTIVE: This study examined whether anxiety and depression were independently associated with elevated blood pressure in elderly persons. METHOD: The study group consisted of 1389 subjects aged 59 to 71 years recruited from the electoral rolls of the city of Nantes (France). Subjects completed the Center for Epidemiologic Studies-Depression scale (CES-D) and the Spielberger Inventory scales to assess depressive symptoms and anxiety symptoms, respectively. Data were collected on sociodemographic characteristics, smoking and drinking habits, medical history, and drug use. Two measures of systolic and diastolic blood pressure were taken after a 10-minute rest. Body mass index was computed from weight and height measurements. Subjects taking antihypertensive drugs (N = 281) were excluded from the present analysis. RESULTS: Depression and anxiety scores were significantly correlated (r = .61 in men; r = .65 in women; p<.001). In univariate analyses, anxiety scores were correlated with systolic and diastolic blood pressure in men, but not in women; blood pressure was not associated with depressive symptoms in either sex. Multivariate logistic regressions, controlling for possible confounders, showed that in both men and women, the risk of high blood pressure increased with increasing anxiety scores; odds ratios for high blood pressure were less than 1 in subjects with depressive symptomatology. CONCLUSIONS: This study suggested that anxiety but not depression was independently associated with an increased risk for high blood pressure.