Histological evaluation of human intraosseous healing responses to the placement of tricalcium phosphate ceramic implants. I. Three to eight months

Eight intrabony lesions in four patients were removed en bloc 3 to 8 months after periodontal flap debridement. At the time of debridement, the position of the gingival margin and the most apically located calculus were notched to serve as reference points. All lesions received "Synthograft" implants and lesions healed uneventfully. Even though these were severely involved periodontal sites, clinical measurements at time of block removal demonstrated gingival recession (average = 2.9 mm) and a gain in clinical closure (average = 2.6 mm). Histologically, graft particles were present in each specimen. They were walled off by collagen and did not appear to enhance new attachment nor did they induce an inflammatory infiltrate. Thus, they seemed to act as nonirritating fillers. Microscopically, closure of the lesions demonstrated repair with limited evidence of new connective tissue attachment. Histologic expression of the clinical gain in closure was the result of closure by long epithelial adhesion (long junctional epithelium) and possible linkage of dentinal collagen with gingival fibers at areas of dentinal resorption. These variations in closure were often seen within the same clinical site.     

Emergency department thoracotomy for penetrating injuries: predictive value of patient classification

In 18 months, 44 patients underwent thoracotomy in an emergency department (ED) for penetrating thoracic injuries. Of 14 patients resuscitated, seven (50%) survived, and all were neurologically intact. Patients were classified according to the quality of signs of life in transit or upon arrival at the ED. Identical survival rates of 29% were noted for patients in Group I (profound shock) and in Group II (agonal), with survival at 14% for individuals in Group III ("dead" on arrival). There were no survivors among patients in Group IV ("dead" on the scene), and ED thoracotomy, in the authors' opinion, is fruitless in this group. In Groups I, II, and III, total salvage from cardiac injuries was six of 24 patients (25%), and for those with non-cardiac injuries, it was one of 11 (9%). The rate of survival from cardiac stab wounds in Groups I, II, and III, was five of 16 (31%) and one of eight (13%) for gunshot wounds. Five of the seven survivors (71%) arrived at the ED by rapid transport without the benefit of any pre-hospital life support. Patient classification appears to be a valuable tool in evaluating the benefit of ED thoracotomy. The neurological status of all survivors and pertinent transportation data should be included in all future studies of ED thoracotomy. "Scoop and run" in the urban setting with rapid transport capability may be superior to pre-hospital stabilization of victims of penetrating thoracic trauma.     

Natural language processing and entrustable professional activity text feedback in surgery: A machine learning model of resident autonomy

BackgroundEntrustable Professional Activities (EPAs) contain narrative ‘entrustment roadmaps’ designed to describe specific behaviors associated with different entrustment levels. However, these roadmaps were created using expert committee consensus, with little data available for guidance. Analysis of actual EPA assessment narrative comments using natural language processing may enhance our understanding of resident entrustment in actual practice.MethodsAll text comments associated with EPA microassessments at a single institution were combined. EPA—entrustment level pairs (e.g. Gallbladder Disease—Level 1) were identified as documents. Latent Dirichlet Allocation (LDA), a common machine learning algorithm, was used to identify latent topics in the documents associated with a single EPA. These topics were then reviewed for interpretability by human raters.ResultsOver 18 months, 1015 faculty EPA microassessments were collected from 64 faculty for 80 residents. LDA analysis identified topics that mapped 1:1 to EPA entrustment levels (Gammas >0.99). These LDA topics appeared to trend coherently with entrustment levels (words demonstrating high entrustment were consistently found in high entrustment topics, word demonstrating low entrustment were found in low entrustment topics).ConclusionsLDA is capable of identifying topics relevant to progressive surgical entrustment and autonomy in EPA comments. These topics provide insight into key behaviors that drive different level of resident autonomy and may allow for data-driven revision of EPA entrustment maps.     

Epi-Inositol and inositol depletion: Two new treatment approaches in affective disorder

Inositol is a simple polyol precursor in a second messenger system important in brain myo-insitol, the natural isomer, which has been found to be therapeutically effective in depression, panic disorder, and obsessive-compulsive disorder in double-blind controlled trials. Recently, epiinositol, an unnatural stereoisomer of myo-inositol, was found to have effects similar to those of myo-inositol to reverse lithium-pilocarpine seizures. We measured the behavior of rats in an elevated plus maze model of anxiety after chronic treatment of 11 daily intraperitoneal injections of epi-inositol, myo-inositol, or control solution. Epi-inositol reduced anxiety levels of rats compared with controls, and its effect was stronger than that of myoinositol. Lithium has been hypothesized to alleviate mania by reducing brain inositol levels. Inositol in brain derives from the second messenger cycle, from new synthesis, or from diet via transport across the blood brain barrier. Because the first two are inhibited by lithium, we propose that an inositol-free diet will augment lithium action in mania by enhancing restriction of inositol.     

Effect of sialyl Lewis(x) oligosaccharide on myocardial and cerebral injury in the pig

BACKGROUND: Although administration of the sialyl Lewis(x) oligosaccharide may reduce myocardial injury after ischemia-reperfusion, its effect on coronary and cerebral microvascular regulation and its clinical application during cardiac operation have not been examined. METHODS: Pigs were placed on normothermic cardiopulmonary bypass after 30 minutes of left anterior descending coronary artery occlusion. The hearts were then arrested with cold high potassium cardioplegia. After 1 hour the cross-clamp was removed and the pigs were weaned from cardiopulmonary bypass and perfused for an additional 1 hour. CY-1503 (a sodium salt of the sialyl Lewis(x) oligosaccharide, n = 6) was administered before reperfusion. Six other pigs received saline vehicle. Endothelium-dependent relaxation of precontracted coronary and brain arterioles (70 to 180 microm) to adenosine 5'-diphosphate and endothelium-independent relaxation to sodium nitroprusside were studied in vitro with videomicroscopy. Control values were obtained from uninstrumented pigs. Myeloperoxidase activity in the myocardium and brain was measured to quantify neutrophil infiltration. Cardiac function and perfusion were assessed by left ventricular systolic pressure, maximum rate of increase of left ventricular pressure, left anterior descending coronary artery blood flow and percent segmental shortening, and cerebral vascular resistance, internal carotid artery blood flow, and the constitutively expressed and inducible isoform of nitric oxide synthase mRNA were measured. RESULTS: The impaired myocardial contractile function after ischemia and cardioplegia was not improved by administration of CY-1503. The reduced endothelium-dependent relaxation responses of coronary and brain arterioles during ischemia followed by cardioplegia and cardiopulmonary bypass were improved with CY-1503, but the altered pattern of organ perfusion was not improved. Myeloperoxidase activity was increased in the heart after ischemia-cardioplegia and in the brain after cardiopulmonary bypass. CY-1503 reduced myeloperoxidase activity in both the myocardium and in the brain. Expressions of myocardial inducible isoform or constitutively expressed nitric oxide synthase were not altered in the heart. CONCLUSIONS: Although the sialyl Lewis(x) oligosaccharide does reduce neutrophil infiltration and endothelial injury in the coronary and cerebral microcirculation after cardiopulmonary bypass, it does not have significant beneficial acute effects on organ perfusion or function in the myocardium or brain.     

Antipsychotic polypharmacy, Part 1: Therapeutic option or dirty little secret?

Antipsychotic polypharmacy is a surprisingly frequent occurrence that can be both justified and unjustifed, depending on how it is used. To the extent that this phenomenon has been unrecognized and is not being studied, it is a "dirty little secret." To the extent that careful clinicians have uncovered a useful strategy for boosting the effectiveness of available antipsychotic monotherapies, it represents an opportunity to improve the outcomes of patients with psychotic illnesses.     

Molecular neurobiology for practicing psychiatrists, part 4: transferring the message of chemical neurotransmission from presynaptic neurotransmitter to postsynaptic gene expression

Neurotransmitters activate genes in their target neurons by precipitating a molecular cascade, which may be the ultimate consequence of chemical neurotransmission. When this transfer is aberrant, a mental disorder may be manifest. When drugs act upon neurons to change gene expression, this could lead to therapeutic actions, side effects, and the long-term consequences of drug abuse.     

Stereopsis after primary in-the-bag posterior chamber implantation in children.

PURPOSE: The purpose of this study was to evaluate visual acuity and binocular function after primary posterior chamber intraocular lens (IOL) implantation in children. PATIENTS AND METHODS: A retrospective chart review of 39 eyes of 31 children was performed. Fifteen eyes with traumatic, 17 with developmental, and 7 with congenital cataracts without any other ophthalmologic problems were examined before and after cataract surgery (irrigation/aspiration procedure with implantation of a posterior chamber IOL). Twelve eyes also received a posterior capsulorrhexis and anterior vitrectomy. The mean age at surgery was 6.9 +/- 3 years (range, 3-12 years). RESULTS: Twenty (51%) of 39 eyes achieved a best-corrected postoperative visual acuity of 20/40 or better (range, 20/200-20/20). The mean postoperative visual acuity was 20/40 in the traumatic and developmental cataract groups and 20/100 in the congenital cataract group. There was a positive correlation between cataract morphology and visual acuity (P<.05). Bilateral cataracts had a better postoperative visual acuity than unilateral cataracts (P <.005). Nineteen (70%) of 27 eyes in which no primary posterior capsulorrhexis had been performed had posterior capsule opacification. Stereopsis was found in 10 of the 31 patients: 43% of the traumatic cataract group, 30% of the developmental cataract group, and 14% of the congenital cataract group. CONCLUSIONS: After capsular bag-fixated IOL, visual acuity and binocular function in children older than 3 years were favorable and the complication rate, excluding posterior capsule opacification, was low.     

Organochlorine pesticide and polychlorinated biphenyl residues in Canada geese (Branta canadensis) from Chicago, Illinois

Breast muscle samples, with or without overlying adipose tissue and skin, were obtained from Canada geese collected in northeastern illinois while undergoing feather molt. Specimens were evaluated for contaminant concentrations to determine if they would be acceptable as human food provided through government-subsidized programs. Samples were baked, allowing fat to drip free, and assayed for persistent organochlorine pesticides and polychlorinated biphenyls. Residues of heptachlor epoxide, dieldrin, DDE and PCBs (as Arochlor 1248) were detected. The specimens contained relatively low concentrations of contaminants, such that US Department of Agriculture residue limits for meat were exceeded in only 1 sample. Baking of breast muscle without the overlying skin and adipose tissue resulted in reductions in concentrations of detectable compounds. Fewer samples baked with the skin attached had detectable concentrations of heptachlor epoxide, dieldrin and PCB then samples cooked without skin; however, the converse was true for DDE. Periodic monitoring for environmental contaminants such as PCBs, exclusion of geese from localities where samples have contaminants such as PCBs, exclusion of geese from localities where samples have contaminants at concentrations that exceed recommended dietary limits, the use of processing and/or cooking methods which remove large amounts of lipid, and advisories that provide information on known health risks are recommended if wild resident Canada geese from the Chicago area are provided as food for underprivileged humans.