Reduction in LBNP tolerance following prolonged endurance exercise training.

Eight young men underwent an 8-month endurance exercise training program. Prior to and following the training program, the subjects' maximal oxygen uptake (VO2max), total blood volume (TBV) and plasma volume (PV), tolerance to lower body negative pressure (LBNP) assessed by the cumulative stress index (CSI) to presyncope, and their hemodynamic responses to 0 to -45 torr LBNP was determined. Hemodynamic measures included rebreathe carbon dioxide cardiac output (Qc), heart rate (HR), directly measured arterial blood pressures (ABP), and strain gauge determination of forearm blood flow (FBF) and leg volume changes (delta LgV). Calculated values of stroke volume (SV), forearm, vascular resistance (FVR), and peripheral vascular resistance (PVR) were made. Following training, each subject had an increased VO2max (mean = +27.4%, P < 0.001), TBV (mean = +15.8%, P < 0.02), and PV (mean = +16.5%, P < 0.02) and each subject had a decreased tolerance to LBNP (mean CSI = -24%, P < 0.001). Stepwise linear regression identified that the major factors to significantly predict the decreased CSI pre- to post-training were a reduced response of PVR to LBNP from -15 to -45 torr (Model R2 = 0.853), the delta TBV (model R2 = 0.981), and the greater post-training reduction in SBP to LBNP of 0 to -45 torr (model R2 = 1.0). These data suggest that physiologic adaptations associated with the increased VO2max and TBV resulting from a prolonged endurance exercise training program can alter the reflex control of vasomotion and cardiac output during LBNP and reduce the LBNP tolerance.     

Making the most of a teachable moment: a smokeless-tobacco cessation intervention in the dental office.

OBJECTIVES. Primary care medical clinics are good settings for smoking interventions. This study extends this strategy with a smokeless tobacco intervention delivered by dentists and dental hygienists in the course of routine dental care. METHODS. Male users of moist snuff and chewing tobacco (n = 518) were identified by questionnaire in clinic waiting rooms and then randomly assigned to either usual care or intervention. The intervention included a routine oral examination with special attention to the part of the mouth in which tobacco was kept and an explanation of the health risks of using smokeless tobacco. After receiving unequivocal advice to stop using tobacco, each patient viewed a 9-minute videotape, received a self-help manual, and was briefly counseled by the dental hygienist. RESULTS. Long-term success was defined as no smokeless tobacco use at both 3- and 12-month follow-ups, with those lost to follow-up counted as smokeless tobacco users. The intervention increased the proportion of patients who quit by about one half (12.5% vs 18.4%, P < .05). CONCLUSIONS. These results demonstrate the efficacy of a brief dental office intervention for the general population of smokeless tobacco users.     

Immunotoxicity assessment of gentamycin and liquamycin

Rats were injected with gentamycin (GEN) or the oxytetracycline, liquamycin 200 (LA200), and multiple immune responses were measured to assess the immunotoxicity of these antibiotics. Animals were treated by sc or im injection for 12 days with either GEN or LA200 given at a therapeutic dose or at 10-, 50-, or 100-fold greater concentrations. The following immune parameters were assessed in each animal: delayed-type hypersensitivity (DTH), natural killer (NK) cell cytotoxicity, antibody production, and synthesis of interleukin 2 (IL2) and gamma interferon (IFN). The DTH response and IFN production in GEN- and LA200-injected animals were suppressed in a dose-dependent manner. Production of IFN was significantly suppressed in all groups treated with LA200. Suppression of DTH was evident when GEN or LA200 were given at the recommended therapeutic dose. Both LA200- and GEN-treated rats had suppressed NK cell cytotoxicity, but only at the highest dosages. Antibody production was suppressed in a dose-dependent manner in LA200-treated rats. Synthesis of IL2 was suppressed in rats treated with the high dose of GEN. Body weight loss occurred, and hepatic and renal toxicity were apparent at the 2 highest dosages of GEN or LA200. It was apparent that relatively high doses of GEN and LA200 can suppress specific and non-specific cell-mediated immune responses. Also, the data suggest the certain immune responses (eg, DTH reaction and possibly IFN production) may be suppressed at the recommended therapeutic doses in the absence of other signs of toxicity. These results indicate that these antibiotics should not be administered at doses or exposure periods in excess of those recommended.(ABSTRACT TRUNCATED AT 250 WORDS)     

Fluid therapy for induced labour under epidural analgesia: biochemical consequences for mother and infant

Two types of fluid regimen were provided for patients having labour induced under epidural analgesia. Reasons for the infusion were to pre-load the circulation before the epidural, and subsequently to sustain maternal hydration. Both fluids were isotonic, one was predominantly saline based (Hartmann's solution) and the other contained both saline and dextrose. Blood glucose and serum sodium, lactate and beta-hydroxybutyrate were measured before the start of induction, at delivery and in the cord sample. Blood glucose and serum sodium were measured in the babies at 12 and 24 h of age. The dextrose-saline fluid caused small but significant changes in blood glucose and serum sodium which did not exceed the normal reference limits for either. The use of Hartmann's solution was associated with considerable rises in maternal serum beta-hydroxybutyrate at delivery. Neither fluid had any significant effect on the blood glucose or serum sodium in infants at 12 and 24 h of age.     

A five-year study of needlestick injuries: significant reduction associated with communication, education, and convenient placement of sharps containers.

OBJECTIVE: To decrease the numbers of needlesticks among healthcare workers. DESIGN: All reported needlestick injuries at Santa Clara Valley Medical Center, San Jose, California, were reviewed, analyzed, and tabulated by the infection control department yearly from 1986 to 1990. SETTING: A 588-bed county teaching hospital in San Jose, California, affiliated with Stanford University. PARTICIPANTS: All employees of Santa Clara Valley Medical Center who reported needlestick injuries on injury report forms. INTERVENTIONS: From April to December 1987, more needle disposal containers were added to as many patient care areas and as close to the area of use as possible. Results of 1986, 1988, 1989, and 1990 analyses were communicated yearly to all personnel, extensive educational programs were conducted in 1987 and 1988, and educational efforts continued in 1989 and 1990. RESULTS: In 1986, there were 259 needlestick injuries at our institution, 22% (32) from recapping. After needle disposal containers were added to all patient care areas, needlestick injuries for 1988 totalled 143, a 45% decrease in the total needlestick injuries and a 53% decrease in recapping injuries. Communication of results to all areas of the hospital and educational activities were started in 1987 and continued through the next 3 years. In 1989, there were 135 needlestick injuries, a decrease of 6% from 1988; recapping injuries decreased 40% from 1988. In 1990, there were 104 needlestick injuries, a 23% decrease since 1989, and a 33% decrease in recapping injuries. The total number of needlestick injuries from 1986 to 1990 decreased by 60%, and those injuries from recapping decreased by 81% to 89%. CONCLUSIONS: We have continued to monitor needlestick injuries, communicate findings to all personnel, and include needlestick prevention in educational programs. We contend that more convenient placement of needle disposal containers, communication of findings, and education do decrease needlestick injuries in healthcare workers.     

Pharmacotherapy of childhood asthma. An inflammatory disease.

The recognition that asthma constitutes 2 kinds of physiopathological reactions, namely bronchospasms (immediate reactions) and inflammatory responses (late reactions), suggests that the treatment should be focused against these events. Furthermore, the allergen provocation model, showing the existence of immediate and late asthmatic reactions, can be used to study the effects of different antiasthmatic drugs. Recently, the importance of inflammation in the pathogenesis of asthma in adults has led to the development of therapeutic regimens in which anti-inflammatory treatments are used frequently as a first-line step in the management of asthma. Although at the moment the hard data showing inflammation in childhood asthma are scarce, it is assumed that childhood asthma constitutes the same kind of chronic inflammatory processes as in adult asthma and that its treatment should also include anti-inflammatory drugs.     

Randomized Controlled Trial of Hands‐and‐Knees Positioning for Occipitoposterior Position in Labor

ABSTRACT: Background: Hands‐and‐knees positioning during labor has been recommended on the theory that gravity and buoyancy may promote fetal head rotation to the anterior position and reduce persistent back pain. A Cochrane review found insufficient evidence to support the effectiveness of this intervention during labor. The purpose of this study was to evaluate the effect of maternal hands‐and‐knees positioning on fetal head rotation from occipitoposterior to occipitoanterior position, persistent back pain, and other perinatal outcomes. Methods: Thirteen labor units in university‐affiliated hospitals participated in this multicenter randomized, controlled trial. Study participants were 147 women laboring with a fetus at ≥37 weeks’ gestation and confirmed by ultrasound to be in occipitoposterior position. Seventy women were randomized to the intervention group (hands‐and‐knees positioning for at least 30 minutes over a 1‐hour period during labor) and 77 to the control group (no hands‐and‐knees positioning). The primary outcome was occipitoanterior position determined by ultrasound following the 1‐hour study period and the secondary outcome was persistent back pain. Other outcomes included operative delivery, fetal head position at delivery, perineal trauma, Apgar scores, length of labor, and women's views with respect to positioning. Results: Women randomized to the intervention group had significant reductions in persistent back pain. Eleven women (16%) allocated to use hands‐and‐knees positioning had fetal heads in occipitoanterior position following the 1‐hour study period compared with 5 (7%) in the control group (relative risk 2.4; 95% CI 0.88–6.62; number needed to treat 11). Trends toward benefit for the intervention group were seen for several other outcomes, including operative delivery, fetal head position at delivery, 1‐minute Apgar scores, and time to delivery. Conclusions: Maternal hands‐and‐knees positioning during labor with a fetus in occipitoposterior position reduces persistent back pain and is acceptable to laboring women. Given this evidence, hands‐and‐knees positioning should be offered to women laboring with a fetus in occipitoposterior position in the first stage of labor to reduce persistent back pain. Although this study demonstrates trends toward improved birth outcomes, further trials are needed to determine if hands‐and‐knees positioning promotes fetal head rotation to occipitoanterior and reduces operative delivery. (BIRTH 32:4 December 2005)