Use of ultrasound to assess healing of a mandibular distraction wound.

PURPOSE: A standardized, noninvasive technique to assess healing of the mandibular distraction wound is not available. Current methods include clinical examination, plain radiography, and computed tomography. These imaging techniques are expensive and obligate the patient to serial radiation exposure. In addition, anatomic overlap and metal artifacts may obscure the distraction gap. In contrast, ultrasound has been shown to be a noninvasive, efficient, and inexpensive way to evaluate bone healing. The purpose of this study was to test the feasibility of ultrasound to evaluate an experimental mandibular distraction osteogenesis wound. MATERIALS AND METHODS: Distraction devices were placed via a submandibular incision into 24 minipigs. The protocol consisted of 0-day latency and distraction rates of 1, 2, or 4 mm/d for a 12-mm gap. The wounds were assessed in vivo after 0, 8, 16, and 24 days of neutral fixation. Ex vivo radiographs were used to estimate bone fill using a semiquantitative score. A semiquantitative ultrasound score was assigned, and the beam penetration depth was measured in millimeters. RESULTS: In all groups, clinical stability of the distraction wound increased with the duration of fixation. Plain radiographs, taken during neutral fixation, showed that the desired distraction gap was achieved and maintained. The ultrasound score increased with fixation time, whereas beam penetration depth decreased as expected. Ex vivo radiographs showed increasing bone fill score with time and paralleled the ultrasound score. CONCLUSIONS: The results of this feasibility study indicate that ultrasound is potentially useful for the assessment of bone formation in distraction osteogenesis wounds.     

Parental Attitudes Toward Breastfeeding: Their Association with Feeding Outcome at Hospital Discharge

Abstract: Background : A woman chooses to breastfeed for many reasons. Recent research, however, suggests that parental attitudes toward breastfeeding are stronger predictors of infant feeding choice than commonly cited sociodemographic factors. The objective of the current study was to compare the infant feeding attitudes of expectant couples, and to determine to what degree their individual attitudes during early pregnancy were predictive of the method of infant feeding at discharge from hospital. Methods : A convenience sample of pregnant women (gestational age 8–12 weeks), who were attending maternity clinics in Glasgow, Scotland, in 2000, completed the 17‐item Iowa Infant Feeding Attitude Scale (IIFAS), together with their partners. Results : The IIFAS was completed by 108 expectant couples. At discharge from hospital 49.1 percent of women were exclusively breastfeeding, and 50.9 percent were exclusively formula‐feeding. A woman's total infant feeding attitude score was significantly correlated with her partner's score(r = 0.67, p < 0.001). There was no difference in the infant feeding attitudes of formula‐feeding couples(p = 0.987), but breastfeeding women tended to be more supportive of breastfeeding than their partners(p = 0.022). Maternal, but not paternal, infant feeding attitude was a significant predictor of the choice of feeding method (OR = 1.16 95% CI = 1.09–1.24). Conclusions : Infant feeding attitudes tended to be shared by expectant couples. Maternal infant feeding attitude was a better predictor of feeding choice than were demographic factors. Paternal attitudes were not found to be independently associated with feeding choice. Identification of women with neutral infant feeding attitudes using the IIFAS may be an effective way of targeting interventions at those women who are most likely to be receptive to such programs.     

PEPTIDES AS NEUROTRANSMITTERS IN VASCULAR AUTONOMIC NEURONS

1. Neuropeptides are present in the majority of autonomic neurons projecting to blood vessels, where they are co-localized with non-peptide transmitters and sometimes with other peptides. 2. Neuropeptides are released from vasoconstrictor and vasodilator nerve terminals after high frequency stimulation (>2–5 Hz) with trains of impulses. 3. Neuropeptides can have potent post-synaptic effects on vascular tone, but often these effects are restricted to selected regions of the vasculature. 4. Post-synaptic effects of neuropeptides tend to be more slowly-developing and more long-lasting than those of non-peptide transmitters. 5. Autonomic vasoconstrictor and vasodilator responses often have multiple phases, with the faster phases being mediated by non-peptide transmitters and the slower phases mediated predominantly by one or more neuropeptides. 6. Some neuropeptides do not seem to have post-synaptic effects in a particular vascular bed, but can have presynaptic actions on neurotransmitter release. 7. Neuropeptides form an important component of the repertoire of neurotransmitters used by vascular autonomic neurons to regulate regional blood flow in response to a range of physiological stimuli.     

A community-based epidemiologic study of health sequelae of exposure to hydrofluoric acid.

An accident at an oil refinery in Texas City, Texas, released around 40,000 lb of hydrogen fluoride, exposing the community to the highly toxic and corrosive substance. A population-based epidemiologic study was conducted to evaluate the impact of the accident on the health of the community. Exposure assessment was done using a multipronged approach through a door-to-door survey of 10,811 individuals. A symptom survey resulting in 1994 completed interviews was conducted with a stratified random sample selected from the exposure study database. The sampling was balanced with respect to age, gender, and predisposition across the three ordinal exposure categories. The results show a strong dose relationship (P < 10(-4)) between the exposure and symptoms reported following the accident and 2 years later, most notably breathing and eye symptoms. However, substantial improvement in health was reported over the 2-year period regardless of the level of exposure. Problems of recall bias and behavioral sensitization are considered and it is recognized that the study may have overestimated the effect. It is also recognized that the study may not have completely unraveled the relative importance of exposure and host response in health outcome, since the two were probably conflated in the exposure measure. Nevertheless, the independence of predisposition and reported level of exposure, the magnitude of effect and its consistency, the unmistakable dose response, the large sample size, and the mutual corroboration of various findings make it difficult to dismiss the interpretation that the hydrofluoric acid exposure indeed caused health problems in the community that continued for at least 2 years after the accident.     

Drug mixture which improves survival of ischemic rabbit epigastric skin flaps

The chief aim of this study was to maximize flap survival by counteracting the pathophysiological changes occurring during ischemia-reperfusion. Rabbit epigastric skin flaps given 21 hours of ischemia were infused intra-arterially with selected drugs at the start of reperfusion. Compared with control infused ischemic flaps, which had a 33% survival rate on day 7 post-ischemia, significant improvement was found with vasodilators nitrendipine (61%) and prostacyclin (65%) and the thrombolytic agent urokinase (65%); marginal improvement with the free radical scavenger desferrioxamine (53%); but no change with streptokinase (44%), heparin (21%), and ATP-MgCl₂ (35%). A drug mixture comprising all of these agents except streptokinase and urokinase produced 87% survival, suggesting an additive effect. Biochemical assays on skin homogenates and blood implicated oxygen free radicals, neutrophil infiltration, and thromboxane in flap failure. These results imply that multiple factors are responsible for ischemic flap failure and that a mixture of drugs needs to be infused to counteract all of the detrimental changes. © 1994 Wiley-Liss, Inc.     

The treatment of late post-traumatic orbital deformities

Trauma to the orbital region may result in fractures of the bony orbit, displacement of which gives rise to malposition of the eye and diplopia. If initial treatment is not feasible or is unsuccessful, later correction may be achieved by osteotomy or reduction and stabilisation of the bony fragments, often with bone grafts. Displaced medial or lateral canthi may need to be repositioned, where feasible in an overcorrected position. Where bone grafts are necessary, the skull is now favoured as the best donor site.     

HEMATOCRIT VALUES DURING PREGNANCY IN A NURSE-MIDWIFERY CASELOAD

This article reviews the normal hematologic changes in pregnancy and the kinetics of iron metabolism. The differences between iron depletion and anemia are described. The hematocrit levels of a nurse-midwifery caseload in a tertiary-care setting are described and compared with recently published population norms. Hematocrits of the sample compared favorably to the population hematocrits until 24 weeks' gestation, when the sample hematocrit mean became statistically lower and remained that way throughout pregnancy. Further analysis was done on the sample hematocrits, comparing differences in parity, age, pregnancy spacing, and AS versus AA hemoglobin. Parous women with a pregnancy interval >12 months had a higher mean hematocrit then nulliparous women. Mean hematocrits of age groups varied significantly only at the 29–32-week interval, with women younger than 18 having lower mean hematocrits than those ≥18. A trend of women with AS hemoglobin having higher hematocrits than women with AA hemoglobin was identified, reaching statistical significance at the 29–32-week interval.