Cerebroprotective effect of stable nitroxide radicals in closed head injury in the rat

Nitroxide stable radicals are unreactive toward most diamagnetic molecules, but readily undergo one-electron redox reactions with paramagnetic species such as free radicals and transition metals, thus serving as cell permeable antioxidants. The involvement of reactive oxygen species in the pathophysiology of neurotrauma has been well established. The neuroprotective properties of three nitroxides: 2,2,6,6-tetramethylpiperidine-1-N-oxyl (TPO), the hydrophilic analog: TPL, and its reduced form: TPH, were tested in a rat model of closed head injury (CHI). CHI was induced in ether anesthetized rats by a weight drop device and recovery was followed for up to 24 h. The ‘clinical status’ was evaluated according to a ‘Neurological Severity Score’ (NSS), at 1 h and 24 h, the difference between these scores, ΔNSS, reflecting the extent of recovery. Edema was assessed by measurement of water content at 24 h. The integrity of the blood-brain barrier (BBB) was investigated using Evans Blue extravasation. TPL, TPH and TPO facilitated clinical recovery, the latter causing a more pronounced effect (ΔNSS = 7.63 ± 0.26 in treated rats vs 4.94 ± 0.48 in control rats, P < 0.001). TPL was found to significantly reduce edema formation (80.13% ± 0.26 vs 83.65% ± 0.49, P < 0.001) and to ameliorate BBB disruption (P < 0.001). The therapeutic window of TPL was found to be in the range of 4 h after CHI. The mechanisms underlying the nitroxide neuroprotective activity presumably involve: (a) reoxidation of reduced transition metal ions; (b) a selective radical-radical reaction; and (c) catalytic removal of intracellular and extracellular O₂⁻. The results indicate that nitroxides could be used in neuroprotective treatment of CHI.     

Colon and rectal surgery without mechanical bowel preparation: a randomized prospective trial

OBJECTIVE: To assess whether elective colon and rectal surgery can be safely performed without preoperative mechanical bowel preparation. SUMMARY BACKGROUND DATA: Mechanical bowel preparation is routinely done before colon and rectal surgery, aimed at reducing the risk of postoperative infectious complications. However, in cases of penetrating colon trauma, primary colonic anastomosis has proven to be safe even though the bowel is not prepared. METHODS: Patients undergoing elective colon and rectal resections with primary anastomosis were prospectively randomized into two groups. Group A had mechanical bowel preparation with polyethylene glycol before surgery, and group B had their surgery without preoperative mechanical bowel preparation. Patients were followed up for 30 days for wound, anastomotic, and intra-abdominal infectious complications. RESULTS: Three hundred eighty patients were included in the study, 187 in group A and 193 in group B. Demographic characteristics, indications for surgery, and type of surgical procedure did not significantly differ between the two groups. Colo-colonic or colorectal anastomosis was performed in 63% of the patients in group A and 66% in group B. There was no difference in the rate of surgical infectious complications between the two groups. The overall infectious complications rate was 10.2% in group A and 8.8% in group B. Wound infection, anastomotic leak, and intra-abdominal abscess occurred in 6.4%, 3.7%, and 1.1% versus 5.7%, 2.1%, and 1%, respectively. CONCLUSIONS: These results suggest that elective colon and rectal surgery may be safely performed without mechanical preparation.     

Role of protein kinase C and the Sp1-p53 complex in activation of p21(WAF-1) expression by 12-O-tetradecanoylphorbol-13-acetate in human T cells

Previous reports have shown that, in certain cell types, p21(WAF-1), which plays a central role in cell proliferation, can be activated by HTLV-I Tax protein and by TPA. Tax and TPA are also known to stimulate HTLV-I gene expression. Since cell proliferation has a major impact on HTLV-I replication, it was of interest to investigate their effect on p21(WAF-1) in human T cells, which are the main target of HTLV-I in human infection. This study demonstrates that p21(WAF-1) is activated in such cells by both factors, each acting through a different mechanism that does not influence the other. The effect of TPA is shown to require PKC activity. Notably, however, examination of different PKC isoforms revealed that PKC-alpha and PKC-epsilon stimulated p21(WAF-1) expression, whereas PKC-eta was rather inhibitory and PKC-beta1 and beta2 were ineffective. All these isoforms were found to be activated by TPA in the employed T cells, but this apparent paradox was resolved by the observation that when coexpressed together in these cells, the stimulatory PKCs override the inhibitory isoform. Further experiments demonstrated that the PKC-induced p21(WAF-1) activation was mediated by binding of Sp1-p53 complex to the second most upstream of the six Sp1 recognition sites present in its promoter and that this effect did not require the cooperation of an p53-binding site.     

Phaeochromocytoma of the urinary bladder

The occurrence of urinary bladder paragangliomas is rare. A 12-year-old Chinese girl who presented with history of blurring of vision was found to have grade IV hypertensive retinopathy. Investigations revealed a phaeochromocytoma on the posterior wall of the urinary bladder. A partial cystectomy with right ureter reimplantation was undertaken and her hypertension was promptly controlled. The diagnosis and management of this rare tumour is discussed.     

Late regeneration of infarcted small bowel mucosa: a case report

Ischemic injury of the small bowel may recover after revascularization, provided that full-thickness infarction did not occur. Animal studies showed that if the mucosal crypts remain viable, rapid mucosal restitution occurs hours after injury. The treatment of transmucosal infarction that does not extend to full wall thickness, however, was not investigated thoroughly. The patient presented had a mesenteric event leading to resection of about half of his small bowel. The unresected segment had severe ischemic injury, which seemed to cause transmucosal, but not transmural, infarction. Imaging of the remaining small bowel revealed a seromuscular layer denuded of mucosa. The ischemic damage was too deep to allow rapid regeneration, and the patient had short-bowel syndrome. A year later, during operation for stricture complications, new mucosa covered parts of the small-bowel surface, encouraging the surgeon to elect a conservative approach. Sixteen months after the injury, normal mucosa covered the entire small bowel, and enteral feeding resumed successfully. This report shows that infarcted small-bowel mucosa may regenerate even months after injury.     

Temporary pacing in the prevention and treatment of tachyarrhythmia

In this article cardiac pacing is approached as a method to prevent and treat tachyarrythmias. The authors describe both the ways and places of stimulation as well as the indication to its use. The risks and complications associated to this method are also mentioned. In conclusion they refer to it as an available alternative to the other forms of antiarrythmic therapy, emphasising its efficacy and safety.     

Disparities in Access to Opioid Treatment Programs and Office-Based Buprenorphine Treatment Across the Rural-Urban and Area Deprivation Continua: A US Nationwide Small Area Analysis

ObjectivesTo measure access to opioid treatment programs (OTPs) and office-based buprenorphine treatment (OBBTs) at the smallest geographic unit for which the Census Bureau publishes demographic and socioeconomic data (ie, block group) and to explore disparities in access to treatment across the rural-urban and area deprivation continua across the United States.MethodsAccess to OTPs and OBBTs at the block group in 2019 was quantified using an innovative 2-step floating catchment area technique that accounts for the supply of treatment facilities relative to the population size, proximity of facilities relative to the location of population in block groups, and time as a barrier within catchments. Block groups were stratified into tertiles based on the rural-urban continuum codes (metropolitan, micropolitan, small town, or rural) and area deprivation index (least-deprived, middle-deprived, most-deprived). The Integrated Nested Laplace Approximation approach was used for statistical analysis.ResultsAcross the United States, 3329 block groups corresponding to 2 915 949 adults lacked access to OTPs within a 2-hour drive of their community and 130 block groups corresponding to 86 605 adults did not have access to OBBTs. Disparities in access to treatment were observed across the urban-rural and area deprivation continua including (1) lowest mean access score to OBBTs were found among most-deprived small towns, and (2) lower mean access score to OTPs were found among micropolitan and small towns.ConclusionsThe results of this study revealed disparities in access to medication-assisted treatment. The findings call for creative initiatives and local and regional policies to develop to mitigate access problems.     

Hereditary renal adysplasia. Apropos of 2 families

Two families with hereditary renal adysplasia are reported. Transmission is dominant autosomal. There were no genital abnormalities.     

Coexistent hereditary coproporphyria and congenital erythropoietic porphyria (Günther disease)

Summary We present data on one patient with an inheritance pattern for two porphyrias. From her mother she inherited the trait of hereditary coproporphyria; from both parents she inherited the trait of congenital erythropoietic porphyria (Günther disease). Enzyme studies confirmed this new type of dual porphyria.