Control of dynamic stability during gait termination on a slippery surface

There are three common ways by which to successfully terminate gait: decreased acceleration of whole-body center of mass (COM) through a flexor synergy in the trail leg, increased deceleration of whole-body COM through an extensor synergy in the front limb, and an energy/momentum transfer to dissipate any remaining momentum if the first two strategies are unsuccessful. Healthy individuals were asked to stop on a slippery surface while we examined their unexpected response to the slippery surface. Kinetic data from the forceplates revealed lower braking forces in the slip trials compared with normal gait-termination trials. Subjects were unable to control their center of pressure (COP) to manipulate the COM as revealed by increased deviations and maximum absolute ranges of COP movement. Subject COM deviated farther in both horizontal planes and lowered further during the slip compared with normal gait-termination trials. Arm movements were effective in dissipating forward COM movement. In addition, there likely was a transfer of forward to lateral momentum to stop forward progression. All recorded muscle activity in the lower limbs and back increased during the slip to provide support to the lower limbs and correct upright balance. The trailing limb shortened its final step to provide support to the lowering COM. The balance-correction response seen here resembles previous reactions to perturbations during locomotion suggesting there is a generalized strategy employed by the nervous system to correct for disturbances and maintain balance.     

Identification of the presence and type of biliary microflora by immediate gram stains.

Immediate gram stains were performed on gallbladder bile aspirated at the start of an operation for biliary disease in 191 consecutive patients undergoing elective biliary surgery. The results of the gram stains were telephoned to the operating theater within 20 minutes of collection. The over-all accuracy rate of the telephone gram stain reports compared with the subsequent bile cultures was 77 percent. The incidence of false-positive results was 12 percent, and false-negative results were recorded in 7 percent. The organism was identified wrongly by the gram stain in 4 percent of patients. These results have improved with experience and the over-all accuracy rate of gram stains on bile over the last 6 months have been 87 percent.     

A potent sorbitol dehydrogenase inhibitor exacerbates sympathetic autonomic neuropathy in rats with streptozotocin-induced diabetes

We have developed an animal model of diabetic sympathetic autonomic neuropathy which is characterized by neuroaxonal dystrophy (NAD), an ultrastructurally distinctive axonopathy, in chronic streptozotocin (STZ)-diabetic rats. Diabetes-induced alterations in the sorbitol pathway occur in sympathetic ganglia and therapeutic agents which inhibit aldose reductase or sorbitol dehydrogenase improve or exacerbate, respectively, diabetes-induced NAD. The sorbitol dehydrogenase inhibitor SDI-711 (CP-470711, Pfizer) is approximately 50-fold more potent than the structurally related compound SDI-158 (CP 166,572) used in our earlier studies. Treatment with SDI-711 (5 mg/kg/day) for 3 months increased ganglionic sorbitol (26-40 fold) and decreased fructose content (20-75%) in control and diabetic rats compared to untreated animals. SDI-711 treatment of diabetic rats produced a 2.5- and 4-5-fold increase in NAD in the SMG and ileal mesenteric nerves, respectively, in comparison to untreated diabetics. Although SDI-711 treatment of non-diabetic control rat ganglia increased ganglionic sorbitol 40-fold (a value 8-fold higher than untreated diabetics), the frequency of NAD remained at control levels. Levels of ganglionic sorbitol pathway intermediates in STZ-treated rats (a model of type 1 diabetes) and Zucker Diabetic Fatty rats (ZDF, a genetic model of type 2 diabetes) were comparable, although STZ-diabetic rats develop NAD and ZDF-diabetic rats do not. SDI failed to increase diabetes-related ganglionic NGF above levels seen in untreated diabetics. Initiation of Sorbinil treatment for the last 4 months of a 9 month course of diabetes, substantially reversed the frequency of established NAD in the diabetic rat SMG without affecting the metabolic severity of diabetes. These findings indicate that sorbitol pathway-linked metabolic alterations play an important role in the development of NAD, but sorbitol pathway activity, not absolute levels of sorbitol or fructose per se, may be most critical to its pathogenesis.     

Parenting stress in first-time mothers of twins and triplets conceived after in vitro fertilization

OBJECTIVE: To examine psychosocial and obstetric outcomes at 1 year postpartum in first-time mothers who conceived after IVF. DESIGN: Prospective cohort study. SETTING: University medical center in the United Kingdom. PATIENT(S): One hundred twenty-nine mothers with a single naturally conceived birth, 95 mothers with a single IVF birth, and 36 mothers with a twin or triplet IVF birth. MAIN OUTCOME MEASURE(S): General Health Questionnaire and Parenting Stress Index. RESULT(S): Twenty-two percent of mothers of multiples had Parenting Stress Index scores indicating severe parenting stress, compared with 5% of mothers of IVF singletons (odds ratio, 5.14 [95% confidence interval (CI), 1.55-16.99]) and 9% of mothers of naturally conceived singletons (odds ratio, 2.76 [95% CI, 1.03-7.4]). Mothers of multiple children conceived by IVF did not have poorer mental health but were less likely to be in paid employment at follow-up than were mothers of singletons conceived by IVF (odds ratio, 0.3 [95% CI, 0.13-0.67]) or naturally (odds ratio, 0.27 [95% CI, 0.12-0.59]). Multiple births were more premature, had lower birth weights, and had more medical complications. They were more likely to have been admitted to special care than were singletons conceived by IVF (odds ratio, 14.6 [95% CI, 5.1-42.0)] or those conceived naturally (odds ratio, 10.59 [95% CI, 3.67-30.57]) CONCLUSION(S): Clinicians should ensure that couples making decisions about embryo transfer have considered the potential psychosocial burden of a multiple birth.     

Radionuclide imaging of the thyroid gland: patterns, pearls, and pitfalls

Optimal thyroid scintigraphy requires an understanding of 1) the embryology, anatomy, and physiology of the thyroid gland; and 2) the properties of the 2 common imaging agents, technetium-99m pertechnetate (Tc-99m) and radioiodine (1-123). The normal gland has a characteristic scintigraphic pattern with these tracers and its uptake can be quantified with 1-123. Thyroid diseases often produce characteristic abnormal patterns. These abnormal patterns could be described as diffuse or focal, homogeneous or heterogeneous, increased or decreased. "Extrathyroidal" localization can be seen with esophageal activity, ectopic tissue, thyroglossal duct cyst, and substernal goiter. Thyroid scintigraphy of neonates, as a follow up to abnormal blood screening, demonstrates typical etiologic patterns. The first step in evaluating a patient with suspected thyroid disease is correlating the normal or abnormal scintigraphic pattern with available biochemical data, clinical history, and physical examination. By integrating the interpretive and technical "pearls" and "pitfalls" outlined in this article, the radiologist can be more confident in establishing a proper diagnosis.     

A comparative study of three methods of nasal irrigation

OBJECTIVE: To assess the effectiveness of three methods of nasal irrigation on distributing saline to the nasal cavity and paranasal sinuses. DESIGN:: A prospective, cross-over study. MATERIALS AND METHODS: Twelve subjects (9 patients with chronic sinusitis after functional endoscopic sinus surgery and 3 healthy controls) underwent nasal irrigation with normal saline containing Technetium 99m sulfur colloid. The distribution of radioactivity was assessed on each subject after three different irrigation techniques: metered nasal spray, nebulization with RinoFlow, and nasal douching while kneeling with the head on the floor. RESULTS: The nasal cavity was well irrigated by all three techniques. Compared with the other two methods, douching was significantly more effective in penetrating the maxillary sinus (P = .036) and frontal recess (P = .003). The sphenoid and frontal sinuses were poorly irrigated by all three techniques. CONCLUSION: Nasal douches are more effective in distributing irrigation solution to the maxillary sinus and frontal recess. This should be the method of choice for irrigating these areas.     

Effect of a back belt on reaching postures

OBJECTIVE: The present study investigated the effect of a back belt on reach actions. SUBJECTS: Sixteen undergraduate college students (8 male students, 8 female students) ranging in age from 18 to 22 years. Thirteen subjects were included in the final analysis. SETTING: The Department of Psychology at Miami University, Oxford, Ohio METHODS: Using a well-established set of procedures developed in our laboratory for studying reaching, seated adult participants reached for and retrieved an object placed at various distances from them. Reach distances included values both closer than and farther than each subject's maximum seated reach. The reach task had 2 conditions: picking up and retrieving a small block and skewering and retrieving a small bead with a needle. For each task condition, each subject either wore the belt or did not use a belt. RESULTS: Results indicate that when subjects wore the belt while reaching, they tended to have initial transition points (sitting to nonsitting) closer to their bodies than while not wearing the belt. That is, for a distant object, subjects were more likely to raise their bodies out of the chair rather than perform an extreme seated reach, possibly acting to preserve a greater margin of safety. CONCLUSIONS: The back belt consistently modified reaching postures by limiting extreme ranges of motion during a task that required enhanced stability. Furthermore, the methodology and analysis presented in this article when applied to chiropractic will allow us to begin thoughtful investigation of the effects of chiropractic adjustments on postural transitions and margin of safety.     

Synergistic activation of innate immunity by double-stranded RNA and CpG DNA promotes enhanced antitumor activity

Double-stranded RNA (dsRNA) and unmethylated CpG sequences in DNA are pathogen-associated molecular patterns of viruses and bacteria that activate innate immunity. To examine whether dsRNA and CpG DNA could combine to provide enhanced stimulation of innate immune cells, murine macrophages were stimulated with poly-rI:rC (pIC), a dsRNA analog, and CpG-containing oligodeoxynucleotides (CpG-ODN). Combined treatments demonstrated synergy in nitric oxide, interleukin (IL)-12, tumor necrosis factor alpha, and IL-6 production. Studies using neutralizing antibodies for type I interferons (IFNs), IFN-alpha and IFN-beta, indicated that nitric oxide synthase synergism is mediated by paracrine/autocrine effects of IFN-beta. In contrast, enhanced cytokine production occurred independent of type I IFN and was maintained in macrophages from IFN-alpha/beta receptor knockout mice. Cotransfection of human Toll-like receptors 3 and 9 (receptors for dsRNA and CpG DNA, respectively) into 293T cells supported synergistic activation of an IL-8 promoter reporter construct by pIC, indicating interaction of the signaling pathways in driving the synergy response. In vivo stimulation of mice with pIC and CpG-ODN demonstrated synergy for serum IL-6 and IL-12p40 levels that correlated with an enhanced antitumor effect against established B16-F10 experimental pulmonary metastases. Treatment of tumor-bearing mice with pIC and CpG-ODN in combination resulted in enhanced nitric oxide synthase expression in lung tissue and enhanced up-regulation of class I major histocompatibility complex on splenic dendritic cells relative to treatments with either agent alone. In conclusion, the combined detection of viral pathogen-associated molecular patterns, i.e., dsRNA and CpG DNA, may mimic definitive viral recognition, resulting in an enhanced innate immune response that could be used for tumor vaccination or immunotherapy.