Synthesis and bacterial mutagenicity of the cyclopenta oxides of the four cyclopenta-fused of isomers of benzanthracene

Many polycyclic aromatic hydrocarbons containing peripherallyfused cyclopenta rings are believed to be activated primarilyby epoxidation of the cyclopenta ring. The cyclopenta epoxidesof a series of four cyclopenta benzanthracene derivatives, benz[e]aceanthrylene-5,6-oxide,benz[j]ace-anthrylene-1,2-oxide, benz(l)anthrylene-1,2-oxideand benz[k]acephenaceanthrylene-4,5-oxide were synthesized fromtheir parent hydrocarbons by formation of the bromohydrin followedby dehydrobromination, and characterized by u.v. – vis,and ¹H n.m.r. spectroscopy and mass spectrometry. The mutagenicityof these compounds was investigated in the Ames plate incorporationassay with Salmonella typhimurium strain TA98. All the oxideswere active without exogenous metabolic activation (170–320His⁺ revertants per nanomole) and also toxic above 0.5 µg/plate.Addition of S9 protein did not increase, and generally decreased,the mutagenicity of the oxides, while toxicity was largely unchanged.These results are consistent with the postulated role of cyclopentaoxides as major contributors to the mutagenicity of the parentcompounds in the Ames assay.     

Peri-ventricular grey stimulation versus motor cortex stimulation for post stroke neuropathic pain.

Central post stroke pain is often difficult to manage satisfactorily with conventional treatment modalities for pain. In the last decade functional neurosurgery has offered hope with motor cortex stimulation achieving significant alleviation of pain in some patients. Unfortunately this has led to the neglect of chronic stimulation of deep grey matter as another modality of treating this condition. In this article we present our experience with motor cortex stimulation and that with deep grey matter stimulation in patients with post stroke pain. We argue that both modalities have a significant role and that what is required are better methods of identifying particular patients who are more likely to respond to one or the other.     

Balanced analgesia after hysterectomy: the effect on outcomes.

Balanced analgesia (an opioid and a nonsteroidal anti-inflammatory agent) after hysterectomy often leads to better postoperative pain outcomes. Researchers compared post-hysterectomy patients who received balanced analgesia with those who received only morphine patient-controlled analgesia, and their relationship with pain scores, ambulation, and hospital length of stay.     

The histopathology of freezing injury to the rat spinal cord. A light microscope study. I. Early degenerative changes

In an effort to develop a method of tissue injury which would provide a model for the study of axonal regrowth in adult mammalian central nervous system (CNS), we have analyzed the effects of freezing in the dorsal columns of more than 200 rat spinal cords. The effects of temperature and time of exposure upon the size, shape, distribution and histologic characteristics of the lesion have been assessed during the first seven days following the injury. The upper threshold for injury occurs at -3 degrees C for 15 minutes. Between -3 degrees C and -12 degrees C the tissue changes vary in extent and characteristics. Selective damage to axons and myelin occurs with sparing of the supportive cells followed by proliferation of a cellular matrix. At seven days, the lesions produced by -8 degrees C for 15 to 60 minutes have neither axons nor myelin sheaths and consist of a dense cellular matrix of macrophages and presumed glial cells. With these tissue characteristics, and the preservation of tissue continuity without obstructive barriers, this model would appear to be potentially suitable for the study of axonal regrowth potential in mammalian CNS.     

Intrafollicular blood flow during human ovulation.

Transvaginal ultrasonography with color flow mapping has been used to study changes in intrafollicular blood flow and morphology during follicular rupture and presumed ovulation in one human volunteer. Detailed monitoring started on day 11 of the menstrual cycle and the follicle began to rupture at 14.30 on day 13. This event was preceded by a defined rise and peak in the level of immunoreactive serum luteinizing hormone (LH) by 42 h and 17 h 20 min, respectively. Blood vessels were clearly visible in the inner ring of the follicle (the granulosa layer) at the time of the LH peak and part of the granulosa (probably containing the oocyte) started to detach before the follicle ruptured. The maximum value for the peak blood velocity in the inner vessels was observed 10 s after the start of follicular rupture and there was a concurrent increase in the impedance to blood flow, as reflected by the resistance index and the pulsatility index. The follicle took 14 min 29 s to empty and the corpus haemorrhagicum started to form about 1 min later. These preliminary data suggest that intrafollicular angiogenesis and changes in blood flow can be monitored by a relatively non-invasive technique. Changes in vascularity might be used to predict imminent ovulation and could possibly be identified or modified biochemically to help achieve or avoid a pregnancy.