Risk factors associated with dental implants in healthy and medically compromised patients.

A total of 104 consecutive patients treated with 313 Nobelpharma implants was studied to determine the medical risks associated with dental implants. There did not appear to be an increased implant failure rate or an increase in perioperative morbidity in patients with a compromised medical status. Age; sex; and concurrent use of hypoglycemic agents, supplemental female hormones, or steroids also did not correlate with increased implant failure or perioperative morbidity. Implant procedures using a variety of pain-/anxiety-control agents failed to reveal any increase in anesthetic-related complications. However, the number of implants placed per patient did correlate with implant failure. It appears that implant surgery and the required anesthetic appear to be safe procedures even in the medically compromised patient.     

Prolongation of the latency period in preterm premature rupture of the membranes using prophylactic antibiotics and tocolysis

Mixed results have been obtained in several studies using tocolysis or antibiotics individually in the treatment of premature rupture of membranes (PROM). We compared the outcomes of a management protocol consisting of tocolysis, prophylactic antibiotic administration, and documentation of pulmonary maturity with a control group treated with passive expectant management for premature rupture of membranes. There were 55 women in the treatment group and 57 women in the control group. The mean latent phase (+/- SEM) in the treatment group was 7.34 (+/- 1.25) days compared with 1.86 (+/- .431) days in the control group (P less than .001). Eighteen of 55 patients (33%) in the treatment group were electively delivered after documentation of lung maturity, contributing to a falsely lowered mean latent phase in the treatment group. Twenty-four patients in the treatment group and 6 in the control group had a latent phase of 5 days or greater (P = .00018). There were 9 postpartum infections in the control group and 10 infections in the treatment group (P = NS). There was no difference in the length of latent phase of patients treated with ceftizoxime compared with the other antibiotics used (cefoxitin, cefazolin, ampicillin), although postpartum ceftizoxime was more effective in preventing postpartum infections (1 of 28 vs 9 of 27) (P = .005). There were fewer infected neonates in the study group, but this was not significant. It appears that treatment with this protocol significantly prolongs the latent phase in patients with preterm PROM without increasing infectious morbidity.     

Effect of an adjacent base on detection of a point mutation by restriction enzyme digestion

While routinely mapping point mutations within the arginase locus of a collection of hyperargininemic patients, we discovered that a base immediately outside a restriction endonuclease recognition site (TaqI) can eliminate cleavage of this site by this enzyme. The genetic lesion lay in a base immediately flanking a TaqI recognition site within exon 8 of the arginase locus and abolished cutting by approximately 80%. We wish to emphasize the necessity of heeding subtle cues frequently encountered while generating restriction enzyme data, because neither Southern blot maps nor endonuclease digestion of polymerase chain reaction amplified products of exon 8 accurately predicted where the point mutation lay. To our knowledge, this is the first instance of inhibition of cleavage by flanking bases occurring on natural (nonsynthetic) D DNA substrates, i.e., within the clinical setting of characterization of a human genetic disorder.     

Coulter counter use in the enumeration of muscle and fat stem cells.

Although the manual counting chamber (hemacytometer) is the gold standard for counting cells, this method is subject to great variability due to the 'human factor'. The automated cell counter (Coulter Counter) can enumerate cells in less time and with greater accuracy than the hemacytometer by removing many of the steps in which errors are made. While the Coulter Counter (and others of its type) has been used for many years in the cell culture field, there have been few studies to validate its use with specific cell types. We conducted several experiments in which we assessed the accuracy of the Coulter Counter over counts made with a hemacytometer as well as validated its use for the counting of satellite cells and preadipocytes.     

高效液相色谱法测定血清中双氯芬酸浓度及在人体的药代动力学

建立了人血清中双氯芬酸的反相高效液相色谱测定方法。该法操作简便、精密度好、方法回收率为９８．２～１０２．５％，日内、日间ＲＳＤ为１．２９～４。５２％，血药浓度在０．２～１０μｇ／ｍｌ范围内呈线性关系，相关系数０；９９９９，当信噪比为２时，最低检测限为１０ｎｇ／ｍｌ。健康志愿者口服１００ｍｇ双氯芬酸肠溶衣片，药代动力学过程符合一室开放模型，消除半衰期为２．１５ｈ。     

Cerebromicrovascular endothelial permeability

Summary Permeability of cerebromicrovascular endothelium has been investigated in a new model of cultured cells. The endothelial cells are grown on dextran microcarriers and constitute a barrier for trypan blue (TB) binding to the dextran beads. Changes in the permeability of microcarrier-cultured endothelium have been investigated during the exposure of cells to arachidonic acid or substances involved either in arachidonate metabolism or stimulation of cAMP. The results demonstrate enhanced TB passage through the endothelial barrier during exposure to high concentrations of arachidonic acid and indomethacin, but not to ibuprofen. The effect of indomethacin could be prevented by pretreatment with dexamethasone. Dexamethasone alone did not influence the barrier. Forskolin, a drug which stimulates the catalytic unit of adenylate cyclase, did not affect the endothelial permeability to TB. These findings support the contention that substances derived from a disturbed cellular membrane contribute to the altered blood-brain barrier function found under pathological conditions.Supported in part by a grant from the Deutsche Forschungsgemeinschaft (Ke 3381/1-1) for Dr. Kempski's stay at NIH     

Functional analysis of the marginating pool of human polymorphonuclear leukocytes

The intravascular pool of human polymorphonuclear leukocytes (PMN) is composed of one compartment which is circulating and another that is marginated to the vascular endothelium. Administration of B-adrenergic agonists leads to a rapid demargination with an increase in the circulating PMN pool. The marginating PMN has previously been stated to represent an older PMN based on a higher cytochemical alkaline phosphatase activity. With the understanding that circulating PMN are heterogeneous with respect to function and size we undertook the present study to evaluate the contribution of the marginating PMN to functional and volume-dependent heterogeneity. We found that PMN isolated 7 min after epinephrine administration, presumably enriched by marginating PMN, were not different in volume, biochemically measured alkaline phosphatase activity, stimulated superoxide anion release, degranulation, or phagocytosis. These data suggest that the circulating and marginating pools of PMN are interchangeable and that the marginating PMN are not enriched by a particular subpopulation of PMN.