Estrogen receptor-alpha knockouts and maternal memory in nulliparous rats.

The current study investigated the role of estrogen receptor alpha (Esr1) in maternal memory in rats, comparing the induction and retention responses of Esr1 knockout (KO) and wild type (WT) nulliparous rats towards foster pups. Thirty days after completion of induction testing, subjects were tested for the retention of maternal care in their home cage and then for maternal behaviors in a novel cage. Both WT and Esr1 KO females displayed similar latencies to respond to foster young during the initial induction testing. Likewise, reinduction latencies to display full maternal responsiveness were similar in the Esr1 KO and WT groups during maternal memory testing in the home cage. However, in the novel cage testing WT subjects displayed modest modifications in maternal care. WT females had shorter latencies to first retrieve and mouth a test pup. These findings suggest that while Esr1 does not appear to affect the establishment of maternal care or the display of maternal memory, it may modulate aspects of pup-directed behaviors associated with the reinduction of maternal care in female rats.

In vitro evaluation of continuous mixed venous oxygen saturation and hematocrit monitors.

Four venous hemoglobin oxygen saturation monitors, two of which provide hemoglobin monitoring, were evaluated and compared to a performance standard (control) during cardiopulmonary bypass (CPB). The CDI 100 Hematocrit/Saturation Monitor, CDI 400, Cobe Hematocrit/Saturation Monitor, and the Baxter Bentley OxySat values were compared to the Radiometer Copenhagen OSM3 Hemoximeter and the Damon International Equipment Company Microbore Centrifuge Hematocrit. The Bentley OxySat meter was found to be the most accurate venous oxygen saturation monitor, with the CDI 100 and the Cobe Hct/Sat monitors correlating closely with the control. Only the CDI 400 failed to correlate with the control. The hematocrit monitors, although useful as trending devices, demonstrated inaccuracies in measurements requiring further refinement.

Theory-based correlations and their role in children's concepts.

Recent accounts of conceptual development have emphasized the important role intuitive theories play in concept formation; however, it is still not clear exactly how these theories exert their influence. We present evidence that elementary school age children use theories to link together specific features associated with individual concepts. The results of our first experiment indicate that theory-based correlations play a prominent role in typicality judgments and in decisions about category membership. In a second experiment, we demonstrate that children's theories play an important role in determining which attributes will be considered most central to the concept. The results of these studies suggest that feature correlations can serve to link children's concepts with their intuitive theories of the world.

A pressure prevention device for burned ears.

Full-thickness burns to the external ear can produce loss of skin and cartilage and can result in severe cosmetic deformity. Even partial-thickness burns render the ear vulnerable to tissue loss if the helix is subjected to pressure from pillows, dressings, or straps that are used to secure endotracheal tubes. Because of the incidence of burned ear deformities and the difficulty in reconstructing the external ear, an ear protection device has been designed. The bilateral ear protection device, referred to as "headgear", is fitted to all patients in the burn center who require intubation for an inhalation injury; it is worn continuously until extubation. During a 15-month period 39 consecutive critically burned patients were fitted with the headgear because of the need for ventilator support and/or for protection of the burned ear(s). Pressure necrosis of ear tissue was prevented in all 33 survivors.

Compliance and durability in pressure garments.

This study examined the pressure volumetric characteristics (compliance) of Jobst (Jobst Institute, Toledo, Ohio), Barton-Carey (Barton-Carey Co., Perrysburg, Ohio), and Tubigrip (SePro Healthcare Inc., Moorestown, N.J.) pressure garments for arms after repeated saturation with lubricating substances and repeated washing/drying cycles. The three treatment groups were each composed of one sleeve from each of the manufacturers and were subjected to 20 washing/drying cycles. In addition, the sleeves in treatment groups 2 and 3 were saturated with cocoa butter and Lubriderm moisturizer, respectively, before each cycle. Circumferential measurements were taken on the proximal forearm of the sleeve at varying degrees of pressure with a Grafco standard sphygmomanometer (Graham Field Inc., Hauppauge, N.Y.) and a Gulick anthropometric tape measure (Creative Engineering, Plymouth, Mich.). Measurements were taken initially and after every fifth washing/drying cycle. Analysis of variance revealed significant results for the main effects and some interactions at the 0.01 level. Overall results showed little change in the Jobst and Barton-Carey garments, whereas the Tubigrip garments displayed an inconsistent pattern.

Endotracheal epinephrine is unreliable.

When intravenous access cannot be obtained in an emergency, the endotracheal route of emergency drug administration can be used for epinephrine, atropine, and lidocaine. Optimal drug dosages for endotracheal administration as well as the amount and type of diluent are presently unknown. We compared central intravenous, peripheral intravenous, intraosseous, and intratracheal administration of epinephrine 1:10,000 in both normotensive and hemorrhagic shock dogs. The shock model consisted of 50% blood volume depletion over 15 min. Epinephrine was administered in a dose of 0.01 mg/kg (0.1 cc/kg) by the intraosseous route, central, and peripheral intravenous routes followed by a 5 cc normal saline flush. Intratracheal administration consisted of epinephrine 0.01 and 0.02 mg/kg diluted 1:1 and 1:2 with normal saline or sterile water and administered deep into the tracheo-bronchial tree using a 30-cm catheter. The effect of epinephrine was assessed by the response of the arterial blood pressure. Epinephrine was equally effective by the intraosseous, central intravenous, and peripheral intravenous routes in terms of time to onset of action, time to peak effect, and magnitude of effect on systolic, diastolic, and mean arterial pressures in both the shock and non-shock animals. The duration of effect was significantly longer (P less than 0.02) for the intraosseous route of administration. The endotracheal route of administration was unreliable and not reproducible in either the normotensive or shock animals. In 8/12 episodes in normotensive animals, including 5 trials with double doses of 0.02 mg/kg and dilutions of 1:1 and 1:2, and in 4/9 studies with shock animals including three with double doses, there was no discernable response of systolic or diastolic blood pressure.

Comparison study of intraosseous, central intravenous, and peripheral intravenous infusions of emergency drugs.

Intraosseous infusion of emergency drugs is a lifesaving alternative to intravenous administration when intravenous access cannot be rapidly established. We studied the comparative pharmacokinetics of the following six emergency drugs and solutions: epinephrine hydrochloride, 0.01 mg/kg; sodium bicarbonate, 1 mEq/kg; calcium chloride, 10 mg/kg; hydroxyethyl starch, 10 mL/kg; 50% dextrose in water, 250 mg/kg; and lidocaine hydrochloride, 1 mg/kg. Studies were conducted in normotensive, anesthetized dogs, with three animals studied with each of the drugs or solutions and each animal being treated with all three routes of administration (central intravenous, peripheral intravenous, and intraosseous) in randomized sequence. The effects of epinephrine were also assessed in a shock model. The intraosseous route of administration was comparable with the central and peripheral intravenous routes for all of the emergency drugs and solutions studied, with equivalent magnitudes of peak effect or drug level and equal or longer durations of action. Time to placement of the intraosseous needle varied from 15 seconds to 5 minutes, with a mean of 60 seconds. Time to placement of the needle varies with the skill and experience of the individual. With experience, all individuals could place the intraosseous needle in 60 seconds or less. The intraosseous route is comparable in effect to the central and peripheral intravenous routes of drug administration for epinephrine, sodium bicarbonate, hydroxyethyl starch, calcium chloride, 50% dextrose in water, and lidocaine and is a clinically feasible alternative when intravenous access will be critically delayed.

The bone marrow as a source of laboratory studies.

The intraosseous route is an emergency alternative to the IV route for the administration of drugs and fluids. Another emergency function of intravascular access is obtaining blood samples for blood gases, laboratory studies, and blood cultures. One of the drawbacks to using the intraosseous route as an alternative to IV access has been the persistent need to establish IV access to obtain blood samples. We obtained bone marrow samples from ten healthy anesthetized dogs and analyzed the usefulness of the samples in providing meaningful laboratory studies when compared with simultaneous arterial and venous samples for blood electrolytes, blood chemistries, blood gases, and hemoglobin. There was no significant difference (P greater than .10) in blood electrolytes (sodium, potassium, chloride, and carbon dioxide) drawn from the intraosseous, arterial, and venous sites. The blood chemistries (blood urea nitrogen, creatinine, total protein, albumin, calcium, phosphorous, uric acid, total bilirubin, and SGOT) also were not significantly different (P greater than .10). Significant differences were obtained for glucose comparing intraosseous with arterial (P = .03), whereas intraosseous versus venous was only marginally significant (P = .06). Significant differences were also obtained for alkaline phosphatase when comparing intraosseous with arterial (P = .03), whereas comparison with venous was only marginally significant (P = .06): lactate dehydrogenase differences were marginally significant when comparing intraosseous with arterial (P = .09) and venous (P = .06) blood. Hemoglobin values were not significantly different when comparing results for the three sites (P greater than .25).(ABSTRACT TRUNCATED AT 250 WORDS)

The safety of intraosseous infusions: risks of fat and bone marrow emboli to the lungs.

The technique of intraosseous infusion is a life-saving emergency alternative when IV access is impossible or will be critically delayed. Concerns about its safety remain, especially concerning the risk of bone marrow and fat emboli to the lungs. We examined autopsy pulmonary specimens on two children who had received intraosseous infusions during resuscitation attempts and found an average of 0.23 to 0.71 bone marrow and fat emboli per mm2 of lung. We studied normotensive dogs with intraosseous infusions of emergency drugs and solutions into the distal femur. Three dogs were studied with each of the following emergency drugs or solutions: controls with normal saline (0.9% NaCl), epinephrine 0.01 mg/kg, NaHCO3 1 mEq/kg, CaCl 10 mg/kg, atropine 0.01 mg/kg, hydroxyethyl starch 6% in normal saline 10 mL/kg, 50% dextrose in water 0.25 g/kg, and lidocaine 1 mg/kg. Four hours after infusion, the animals were killed, and representative sections of the lung were examined with oil red-0 and hematoxylin and eosin stains for the presence of fat and bone marrow emboli. Fat and bone marrow emboli were found in all lung sections, varying from 0.11 to 4.48 emboli/mm2 lung (mean, 0.91 emboli/mm2 lung) for the emergency drugs and solutions and 0.06 to 0.53 emboli/mm2 (mean, 0.29 emboli/mm2 lung) for the controls. Analysis of variance revealed no significant difference (P = .07) in mean number of fat and bone marrow emboli per square millimeter of lung among the emergency drugs and compared with controls.(ABSTRACT TRUNCATED AT 250 WORDS)

New method for continuous measurement of nocturnal penile tumescence and rigidity.

A new technique for continuous recording of penile rigidity and tumescence has been developed. This methodology has been utilized in initial studies to define erectile function in both normal and impotent males. Accurate recording of tumescence and rigidity have been utilized to document the decline in erectile function associated with organic impotence.

When is arthrography indicated in Legg-Calvé-Perthes disease?

We evaluated plain radiographs and arthrograms of twenty-one children with active Legg-Calvé-Perthes disease in order to determine the value of the arthrography. We found that when epiphyseal protrusion was shown by the arthrograms it could be seen on the plain radiographs as well in all patients. Also, an acetabulum-head index of less than 90 or an acetabulum-head quotient of less than 92 as determined on plain radiographs correlated well with a diagnosis of protrusion. Thus, an arthrogram is not necessary to make the diagnosis of protrusion in most patients. The arthrogram is more useful in delineating changes in the articular surface for prognoses concerning arthritis and in tailoring the treatment to the individual patient.

A cognitive style approach to creative thought.

Creative thinking was explored from several approaches to further understanding of the interrelationship of perception, personality, and cognition. College students (N = 45) were administered the Group Embedded Figures Test (GEFT), the Remote Associates Test (RAT), a questionnaire concerning RAT strategy, and two self-report scales. Field independent subjects were found to be significantly (p less than .001) more creative than field dependents. Correlations between the RAT and GEFT and the self-report measures of conformity and creativity, while largely nonsignificant, were in the predicted directions. Results demonstrated that advanced strategy levels and insightful responses were significantly related to high performance on the RAT. Theoretical links between cognitive style and Piagetian concepts were discussed in regard to creative thought. Overall, these findings support the contention that the creative processes should be studied, not as isolated structures, but with relational and multifaceted emphasis.