Cervical lymph nodes are found in direct relationship with the internal carotid artery: Significance for the lymphatic drainage of the brain

The brain has no conventional lymphatics, but solutes injected into it drain along artery walls and reach lymph nodes in the neck. This study seeks to identify cervical lymph nodes related to the human internal carotid artery (ICA) that could act as the first regional lymph nodes for the brain. Bilateral dissections were carried out on four embalmed human heads, from the level of the carotid bifurcation in the neck, to the base of the skull. Lymph nodes from every specimen were processed for histological examination. A total of 51 deep cervical lymph nodes were identified: 12 lymph nodes (confirmed by histological examination) were observed to be in direct relationship with the ICA. These lymph nodes were found within the carotid sheath and had average diameters of 13.5 × 4.8 mm. Solutes and interstitial fluid from the brain may drain along the walls of cerebral arteries and reach these lymph nodes. They may be sites of stimulation of immune responses against antigens from the brain. Clin. Anat. 23:43–47, 2010. © 2009 Wiley‐Liss, Inc.     

Intra-specific variation in resting metabolic rate in MF1 mice is not associated with membrane lipid desaturation in the liver

The 'membrane pacemaker' hypothesis provides a putative mechanistic linkage between variations in energy metabolism, rates of ageing and lifespan across different species. Within species we have found positive associations between longevity and metabolism, which contrast the inter-specific trends. It is of interest to know therefore how levels of lipid desaturation in membranes are linked to variation in metabolism between individuals within species. We explored this problem by extracting membrane fatty acids from the livers of mice that varied in their metabolic rate, in a strain (MF1) where we have previously demonstrated a positive association between metabolism and lifespan. We measured resting metabolic rate (RMR) in 60 mice, each measured on three occasions, and measured their body compositions using dual energy X-ray absorptiometry (DXA). We selected 28 individuals that exhibited a wide variation in their mean resting metabolic rates (RMR) and extracted membrane lipids from the livers of these mice post mortem and analysed them for the patterns of contribution of different fatty acids. We then sought associations between the levels of membrane desaturation and the individual variability in RMR, using the proportional contributions of each fatty acid as predictors in a stepwise regression or by re-describing the variation in fatty acyl lipids using a PCA analysis and then seeking associations between scores on the derived components and RMR. We used whole animal RMRs and also RMR with the effects of body composition (fat free mass) removed. The level of individual variation in RMR was consistent with our previous observations. There was a significant positive association (p=0.019) between the proportion of palmitic acid (16:0) in the membranes and RMR, which was strengthened (p=0.014) when we adjusted RMR for differences in fat free mass. The proportion of palmitic acid (16:0) explained 20.9% of the individual variation in residual RMR. There was no association between RMR or mass adjusted RMR and the proportional representation of any other fatty acid, including 22:6 (DHA) predicted by the membrane pacemaker hypothesis to be of particular significance. High levels of saturated fatty acids in the membranes of mice with high rates of metabolism may contribute to their greater longevity, but the mechanism tying together increased membrane saturation with elevated RMR remains unclear.     

Female and male partner age and menotrophin requirements influence pregnancy rates with human menopausal gonadotrophin therapy in combination with intrauterine insemination

This study analyses the influence of female and male patient age and human menopausal gonadotrophin (HMG) requirements on clinical pregnancy rates and live birth rates with ovulation stimulation using HMG in combination with intrauterine insemination (IUI). In this study, 363 consecutive HMG/IUI treatment cycles in 184 patients carried out at a university fertility centre were analysed in a retrospective fashion. The main outcomes measured were clinical pregnancy rates and live birth rates. Increased female partner age (> or = 35) and male partner age (> or = 40) were found to negatively influence pregnancy rates with HMG/ IUI therapy. In addition, this study demonstrated a critical threshold of HMG requirements beyond which pregnancy did not occur. No pregnancies occurred in treatment cycles requiring > 25 ampoules (1875 IU) of menotrophins to achieve follicular maturity, irrespective of patient age. In conclusion, female partner age, male partner age, and HMG requirements all significantly influence pregnancy rates with HMG/IUI therapy.      

Rat myometrial smooth muscle cells express endothelial nitric oxide synthase

We examined if rat myometrial cells in culture generate nitric oxide (NO) and express various isoforms of NO synthase (NOS). Myometrial cells isolated from rats on day 18 of gestation were incubated with various stimulators and inhibitors of NOS for 24 and 48 h, and NO production was evaluated by measuring nitrites in the media and NOS proteins in the cell lysates. NO was produced by myometrial cells and its production inhibited by N(G)-methyl-L-arginine (L-NMMA). This inhibition was reversed by L-arginine (3 mM). Interleukin-1beta (IL- 1beta) significantly stimulated NO production, in a dose-dependent manner. The IL-1beta-stimulated NO production was inhibited by the NOS inhibitor, L-NMMA, whose effects were reversed by L-arginine. Abundant NOS III protein was detectable in freshly isolated myometrial cells, and this was maintained in culture in the presence of fetal bovine serum (FBS; 10%). In the absence of FBS, NOS III levels decreased significantly (by 90%) within 24 h. In contrast, NOS I and NOS II proteins were undetectable in freshly isolated muscle cells and in cells cultured without IL-1beta. However, NOS II protein in these cells was induced by IL-1beta. Thus, NO is produced by myometrial cells through the NOS III isoform, and the myometrial NO may be important in maintaining uterine quiescence during pregnancy.      

Colorectal hemangioma: radiologic findings

The authors correlated radiographs with the clinical and histologic data of 12 patients with colorectal hemangioma. All patients presented with rectal bleeding, which was chronic in seven. Phleboliths were also visible in seven cases, which correlated with chronic bleeding in five. On barium studies, three masses were soft and three produced rigid narrowing. The atypical features of rigid luminal narrowing, which might mimic a carcinoma, and hypovascularity correlated with chronic bleeding or visible phleboliths, which suggest the correct diagnosis of colorectal hemangioma.