Effect of Human Milk and its Components on Streptococcus Mutans Biofilm Formation.

OBJECTIVE: This study investigated the effects of human breast milk and its components on the nutritional aspect of the caries process due to Streptococcus mutans UA159 biofilm formation. STUDY DESIGN: Human breast milk was collected from 11 mothers during 3-9 months postpartum. To test for the effect on biofilm formation, a 16-hour culture of S. mutans was treated with dilutions of human breast milk and several major components of human breast milk, lactose, lactoferrin, IgA, and bovine casein in sterile 96-well flat bottom microtiter plates for 24 hours. The biofilms were fixed, washed, stained with crystal violet, and extracted. Absorbance was measured to evaluate biofilm growth mass. RESULTS: Dilutions 1:10-1:2,560 of the human breast milk samples increased biofilm formation by 1.5-3.8 fold compared to the control. Lactoferrin decreased biofilm formation significantly in all dilutions (average milk concentration of 3 mg/ml). Lactose had no effect at average breast milk concentrations (60 mg/ml) except at its lowest concentration (15 mg/ml) where it was increased. IgA significantly decreased biofilm formation at its highest concentration of 2,400 µg/ml (average milk concentration 600 µg/ml). Casein caused significantly increased biofilm formation at all concentrations tested above the average milk content (2.3 mg/ml). CONCLUSIONS: The results of this study demonstrate an increase in S. mutans biofilm formation by human breast milk 3-9 months post partum. Among its major components, only casein significantly increased biofilm formation among the concentrations analyzed. Lactose had no effect except at 15 mg/ml. Lactoferrin and IgA significantly decreased S. mutans biofilm formation at their highest concentrations. This information expands the current knowledge regarding the nutritional influence of breastfeeding and validates the necessity to begin an oral hygiene regimen once the first tooth erupts.

Native Language Spoken as a Risk Marker for Tooth Decay.

OBJECTIVE: The purpose of this study was to assess dmft, the number of decayed, missing (due to caries), and/ or filled primary teeth, of English-speaking and non-English speaking patients of a hospital based pediatric dental clinic under the age of 72 months to determine if native language is a risk marker for tooth decay. STUDY DESIGN: Records from an outpatient dental clinic which met the inclusion criteria were reviewed. Patient demographics and dmft score were recorded, and the patients were separated into three groups by the native language spoken by their parents: English, Spanish and all other languages. RESULTS: A total of 419 charts were assessed: 253 English-speaking, 126 Spanish-speaking, and 40 other native languages. After accounting for patient characteristics, dmft was significantly higher for the other language group than for the English-speaking (p<0.001) and Spanish-speaking groups (p<0.05), however the English-speaking and Spanish-speaking groups were not different from each other (p>0.05). CONCLUSIONS: Those patients under 72 months of age whose parents' native language is not English or Spanish, have the highest risk for increased dmft when compared to English and Spanish speaking patients. Providers should consider taking additional time to educate patients and their parents, in their native language, on the importance of routine dental care and oral hygiene.

The borderline hypertensive rat (BHR) as a model for environmentally-induced hypertension: a review and update.

In recent years, the burgeoning disciplines of health psychology and behavioral medicine have renewed interest in the important role that environmental factors can play in the disease process. Nowhere is this concern more well-founded than in the area of cardiovascular disorders, particularly hypertension. Epidemiologists and clinicians have long suspected that stressful life events can be a sufficient trigger for the expression of hypertension in some individuals. To understand better the ways in which these variables interact in the disease process, researchers have tried, with limited success, to produce experimental hypertension in animals by exposing them to stressful environmental paradigms. Additionally, recent investigations using the borderline hypertensive rat (BHR) have demonstrated the important role genetic factors can play in mediating both the behavioral and cardiovascular responses to environmental stressors. The current paper will review these attempts and discuss recent data from experiments using a relatively new animal model that appears to be especially appropriate for the study of environmental-genetic factors in the elaboration of essential hypertension. We will also discuss potential mechanisms by which environmental stress influences arterial pressure and suggest avenues for further inquiry into the stress-disease relationship.

Lesions of the anteroventral third ventricle prevent salt-induced hypertension in the borderline hypertensive rat.

Many forms of experimental hypertension depend on the integrity of the periventricular tissue surrounding the anteroventral third ventricle. The current investigation examined the extent to which this forebrain area is necessary for the elaboration of salt-induced hypertension in the borderline hypertensive rat. Eight-week-old male rats were given either electrolytic lesions of the anteroventral portion of the third ventricle region or sham lesions. All rats were then placed on a high salt diet (8% NaCl) for 10 weeks. At the conclusion of this dietary period, direct measurement of resting mean arterial pressure revealed that borderline hypertensive rats with lesions of the anteroventral portion of the third ventricle had significantly lower blood pressure (128.4 +/- 5.1 mm Hg) compared with sham-operated rats (148.1 +/- 4.1 mm Hg).

Lesions of the anteroventral third ventricle and development of stress-induce hypertension in the borderline hypertensive rat.

The anteroventral third ventricle (AV3V) region plays a critical role in the pathogenesis of many forms of experimental hypertension. The present study sought to determine whether the integrity of this area was necessary for the development of stress-induced hypertension in the borderline hypertensive rat (BHR). Male BHRs were assigned to three groups at 8 weeks of age: 1) AV3V lesion, 2) sham lesion, and 3) maturation control. BHRs with AV3V and sham lesions were exposed to 12 weeks of conflict stress (2 hr/day, 5 days/wk). At the end of the conflict protocol period, direct measurement of resting mean arterial pressure indicated that BHRs with sham lesions had significantly higher blood pressure (153 +/- 2.9 mm Hg) than rats with AV3V lesions (126 +/- 5.2 mm Hg) and maturation control rats (133 +/- 4.3 mm Hg). Although AV3V lesions prevented stress-induced hypertension in BHRs, these rats were still capable of transiently raising blood pressure. Specifically, the results also indicate that BHRs with AV3V lesions showed greater increase in blood pressure in response to an electric foot-shock paradigm. This study suggests a critical role for this forebrain region in the production of stress-induced hypertension in genetically predisposed animals.

Exercise training attenuates stress-induced hypertension in the rat.

The ability of exercise training to block the generation of hypertension produced by chronic stress in the borderline hypertensive rat was tested. Twenty-three male borderline hypertensive rats, F1 offspring of spontaneously hypertensive and Wistar-Kyoto rats, were divided into three groups. Two groups (8 rats per group) were subjected to 2 hours of daily, predictable, uncontrollable tail shock for 12 weeks. One of these groups was also given 2 hours of daily swim stress (exercise trained). A third group served as a maturation control and received neither intervention (n = 7). After 12 weeks of stress, direct recording of blood pressure verified the pattern observed with tail cuff: shock only group, 180/118 +/- 3/3 mm Hg; exercise-trained and shocked group, 166/108 +/- 4/2 mm Hg; and control group, 160/98 +/- 6/4 mm Hg (mean +/- SEM). Systolic and diastolic blood pressures in the shock only group were significantly higher than in both the other groups (p less than 0.05). The control group differed from the exercise-trained and shocked group only in diastolic BP (p less than 0.05). During a short-term stress session plasma norepinephrine levels in the exercise-trained and shocked group were significantly lower than those in the shock only group (555 +/- 56 vs 776 +/- 84 pg/ml; p less than 0.05). These results indicate that an alteration of autonomic function resulted from the exercise training, but its contribution to the resistance of the exercise-trained and shocked rats to stress-induced hypertension is unclear.

The effects of intracerebroventricular injection of clonidine on conditioned pressor and adrenergic responses in rats.

Studies from this laboratory have shown that the first filial offspring of female spontaneously-hypertensive rats and male Wistar-Kyoto (WKY) normotensive rats develop stress-induced hypertension. The present study sought to examine the effects of intracerebroventricular administration of clonidine (8 micrograms) on cardiovascular and sympathoadrenal responses to aversive classical conditioning in these borderline hypertensive rats (BHR) and in normotensive WKY control rats. Clonidine caused significant reductions in resting arterial pressure, vascular resistance, heart rate and concentrations of epinephrine (E) in plasma for both hypertensive and normotensive rats. Central administration of normal saline to control rats of each strain did not alter basal cardiovascular or sympathoadrenal function. The presentation of a conditioned stimulus (CS) elicited a significant increase in arterial pressure and total peripheral resistance in hypertensive rats treated with saline and clonidine and in normotensive rats treated with saline. In contrast, normotensive rats treated with clonidine showed no increases in arterial pressure or vascular resistance following the onset of the conditioned stimulus. The aversive conditioning session instigated significant increases in the concentrations of norepinephrine (NE) and E in plasma in saline-treated rats. Hypertensive and normotensive rats treated with clonidine-showed a blunted increase in plasma concentrations of NE and E during this period; however, concentrations of E in hypertensive rats increased significantly from the baseline period after injection. These data suggest that an abnormality in central alpha 2-adrenoceptor-mediated inhibition of sympathoadrenal discharge and sympathetic vasomotor tone may predispose the hypertensive rat to develop stress-induced hypertension.

Haemodynamic responses to conflict stress in borderline hypertensive rats.

Chronic exposure to a shock-shock conflict paradigm (2 h/day, 5 days/week for 12 weeks [1]) produces hypertension in the borderline hypertensive rat (BHR), a cross between the spontaneously hypertensive rat (SHR) and the Wistar-Kyoto rat (WKY). The purpose of the present study was to characterize the regional haemodynamic responses which take place during conflict-stress. A pulsed Doppler flowmeter and miniature probes implanted on the left renal and superior mesenteric arteries and the abdominal aorta were used to record changes in regional flow velocity. Recording of mean arterial pressure (MAP) allowed changes in regional resistance to be calculated. The first conflict session produced intense splanchnic and renal vasoconstriction and hindquarter vasodilation. Pressor responses were moderate. A second group of BHRs was studied during conflict sessions 17-18, prior to the development of hypertension. This group exhibited faster habituation to the stress than the group studied during the first conflict session: MAP and mesenteric resistance returned more rapidly towards pre-stress levels. Relative to naive control rats, this group exhibited a larger peak MAP and less tachycardia in response to a neutral stressor (air-jet stress) and a smaller reduction in renal resistance in response to ganglionic blockade. These data suggest that in this model, pressure load per se is moderate. More attention should be directed towards the role of trophic effects of the neurohumoral factors responsible for the pronounced constriction of splanchnic and renal vasculature in producing hypertension.

Cardiovascular and sympathoadrenal responses to stress in swim-trained rats.

Chronic exposure to swim stress (i.e., training) is associated with functional adaptations of the cardiovascular system. On the other hand, repeated exposure to tail shock, an emotional stress, often results in deleterious changes in resting blood pressure and myocardial pathology. We hypothesized that the pathological adaptation following chronic exposure to tail shock was associated with a larger acute physiological response compared with swim stress. Therefore, acute responses to swim and shock stress were compared. A second concern of this study examined the extent to which adaptation to swim training influences responses to predictable tail shock stress. The cardiovascular and sympathoadrenal responses to swim stress, using 1% body wt attached to the tail, were compared with predictable tail shock (0.2-0.4 mA intensity, 1-s duration, 1/min) in two groups of Long-Evans male rats. In the first, 11 rats were studied following 5-7 wk of swim training, consisting of daily 1-h sessions of swimming with 2% body wt attached to their tails. They were compared with an age-matched nontrained (NT) group (n = 8). During swimming, the trained animals showed significantly lower heart rate (387 +/- 10 vs. 449 +/- 18 beats/min) and significantly lower lactate (0.9 +/- 0.09 vs. 2.0 +/- 0.24 mmol/l), epinephrine (332 +/- 57 vs. 739 pg/ml), and corticosterone (32 +/- 10 vs. 62 +/- 9 micrograms/dl) responses. Systolic and diastolic blood pressures were elevated in swim stress by the same degree in trained (167/110 mmHg) and NT (177/116 mmHg) rats.(ABSTRACT TRUNCATED AT 250 WORDS)

The borderline hypertensive rat: a model for studying the mechanisms of environmentally induced hypertension.

The borderline hypertensive rat (BHR) is a first-generation cross between the spontaneously hypertensive rat and the normotensive Wistar-Kyoto rat. The BHR develops frank hypertension when chronically stressed or when fed a high-sodium diet. Stress-induced hypertension can be blocked by exercise. The role of the central nervous system and kidney in hypertension development in this model is discussed.

Clonazepam for the treatment of lancinating phantom limb pain.

OBJECTIVE: To propose clonazepam for use in the empiric treatment of shooting/shocking phantom limb pain. SETTING: Outpatient pain clinic associated with a university hospital. PATIENTS: Two patients with phantom limb pain after total hip disarticulation. INTERVENTIONS: Treatment with clonazepam. RESULTS AND CONCLUSIONS: Clonazepam provided effective relief for > 6 months in two patients with shooting/shocking phantom limb pain. Although clonazepam therapy is not new, it appears to have been omitted from current pain texts and journals as a treatment option for phantom limb pain.

Early environmental influences can attenuate the blood pressure response to acute stress in borderline hypertensive rats.

The objective of this experiment was to test the hypothesis that early environmental influences could affect cardiovascular reactivity to acute stress in borderline hypertensive rats. This study utilized a cross-fostering paradigm in which borderline hypertensive rat (BHR) pups were reared by their natural spontaneously hypertensive rat (SHR) mothers, by an adoptive SHR dam, or by an adoptive Wistar-Kyoto female. Several maternal behavior measures were taken throughout weaning. Cardiovascular responses to acute stress were measured in adult BHR offspring. SHR dams spent significantly more time engaged in arched, as contrasted with passive, nursing behaviors throughout the preweaning period. Although strain of dam had no effect on resting blood pressure or heart rate, BHR reared by WKY dams had a greatly reduced blood pressure response to acute stress compared with BHR raised by either natural or adoptive SHR dams. These results suggest that the expression of cardiovascular characteristics in the BHR can be modified by early environmental influences and support the hypothesis that the expression of the hypertensive phenotype in the BHR is dependent upon information that is conveyed both genetically and environmentally.

Central amygdaloid lesions attenuate cardiovascular responses to acute stress in rats with borderline hypertension.

The present study tested the hypothesis that lesions of the central nucleus of the amygdala (CeA) would reduce the cardiovascular responses to acute stress in a rodent model that is genetically predisposed toward hypertension. Male borderline hypertensive rats (BHR) were given bilateral electrolytic lesions directed to destroy the CeA or were subjected to a sham procedure. Direct measurements of blood pressure and heart rate were recorded during rest, during 10 min of acute stress, and for 10 min following stress. Analysis of the data revealed that BHR with CeA lesions had a significant attenuation of the stress-induced pressor response compared to sham-operated subjects. Behavioral measures taken in an open field chamber before and after lesions revealed no differences in numbers of squares crossed or rearings. These results suggest that the CeA is an important neural structure in mediating cardiovascular responses to acute stress in a model susceptible to environmentally induced hypertension.

Baroreflex function in chronically stressed borderline hypertensive rats.

A number of previous studies have demonstrated that some aspect of baroreflex function is altered as hypertension develops. However, no studies have determined whether a chronic stressor can alter baroreflex function in the resting state. In the present study, male borderline hypertensive rats (BHR) were divided into three groups: control, stressed daily for 5 weeks, and stressed daily for 11 weeks. At the appropriate time, 7 different dosages of angiotensin II (AII) were given intravenously as a bolus injection. Heart rate (interbeat interval, or IBI) and mean arterial pressure were tracked for 90 subsequent beats. For each group, intercorrelations between pressure and IBI were obtained. In addition, overall means of pressure and IBI for each dosage were computed for each group and plotted. Higher dosages of AII were required to produce a significant correlation between pressure and IBI in the 5-week group compared to control. In the 11-week group, only the highest dosage yielded a significant correlation between pressure and IBI. When data were expressed in terms of the highest pressure and its corresponding IBI for each group, the 5-week-stress group had a shift in set point compared to control. The 11-week group showed a shift in set point and a reduction in gain compared to control animals. The similarity between these findings and those for other models of hypertension is discussed, with special emphasis on the potential role of the central nervous system.

Dam strain affects cardiovascular reactivity to acute stress in BHR.

The effect of maternal strain on reactivity to acute stress was studied in F1 reciprocals produced by crossing the spontaneously hypertensive rat (SHR) with its normotensive progenitor, the Wistar-Kyoto (WKY). This F1 generation, known as the borderline hypertensive rat (BHR), is genetically predisposed to develop hypertension in response to chronic stress or high dietary sodium. Reciprocals, considered to be genetically equivalent aside from sex-linked traits, differ in strain of dam during intrauterine and preweanling development. At 17 weeks of age, reciprocal F1 males did not differ in open-field behavior (squares crossed, rearings, and defecation measured over 3 days in 15-min sessions) or in home-cage measurements of mean arterial pressure (MAP) and heart rate (HR). However, different patterns of cardiovascular reactivity were displayed to transfer and footshock. While WKY-mothered rats reacted with graded pressor responses, SHR-mothered rats responded maximally to transfer, showed no additional increase to footshock, and maintained peak responding after footshock was terminated. Such reactivity differences may mediate the impact of environmental variables on the genetic disposition to hypertension.

Blood pressure and heart rate responses to environmental stress in the spontaneously hypertensive rat.

Blood pressure and heart rate responses of the spontaneously hypertensive rat (SHR) and the Wistar-Kyoto rat (WKY) to mild restraint and tone-shock pairings were compared during a pre-stress, aversive conditioning and post-stress period, after five previous days of exposure to the paradigm. Although SHR and WKY showed similar responses to the onset of the pre-stress period, SHR showed significantly larger blood pressure responses following the onset of the conditioning than WKY. Furthermore, WKY showed a significant blood pressure and heart rate reduction during the conditioning session which was absent in the SHR. During the post-stress period, the blood pressure of SHR remained significantly elevated compared to their home cage rest values, but the blood pressure of WKY returned to basal levels. It is concluded that while the SHR is more reactive than the WKY to stimulus onset, the major source of between-strain differences after 20 min relates to differences in adaptation to continued environmental stimulation. This can lead to exaggerated estimates of physiological reactivity of the SHR, and is supportive of Folkow's view that SHR are both hyperreactive and show more prolonged defense reactions.

The pediatrician's involvement in prevention and treatment of oral disease in medically compromised children.

Significant oral health problems are associated with medical, physical, or mental disorders that occur in children. The pediatrician has the opportunity through early intervention to set the tone for a health care practice that will improve the quality of life for many disadvantaged children. When the pediatrician and pediatric dentist work hand in hand, the children can often expect a happy, healthy future.

Managing patients who have seizure disorders: dental and medical issues.

Some dental professionals may have concerns about treating patients who have seizure disorders. The authors contend that increased knowledge about seizures and how to manage them may make dental professionals more comfortable. This article reviews the various seizure types, discusses commonly used anticonvulsants and their side effects and outlines some special concerns dentists may have in providing care to these patients.

Intraoperative hypothermia associated with lower extremity tourniquet deflation.

STUDY OBJECTIVE: To determine the rapidity and extent of core temperature decrease following release of a lower extremity pneumatic tourniquet. DESIGN: Prospective study. SETTING: Inpatient surgery in a university trauma center. PATIENTS: 11 ASA status I and II adults undergoing unilateral lower extremity fracture fixation in which a tourniquet was used, with general anesthesia. INTERVENTIONS: Temperature was measured in the esophagus before and after lower extremity tourniquet release. MEASUREMENTS AND MAIN RESULTS: Tourniquet times ranged from 41 to 129 minutes (mean 98.5 +/- 9.1 minutes). Following tourniquet deflation core temperature decreased in all patients, with a maximal decline at 10 minutes, the termination of measurements, although trending downward. Esophageal temperature decreased an average of 0.46 degree C +/- 0.2 degree C at 5 minutes, and 0.67 degree C +/- 0.2 degree C at 10 minutes following tourniquet release, respectively. Temperature changes were significant (p = 0.0001) at both time intervals. CONCLUSION: Core temperature drops significantly immediately following release of the tourniquet at the esophageal temperature monitoring site. This decrease is the result of cooling of systemic blood reperfusing the hypothermic limb, and mixing of cool, "washed out" blood with the systemic circulation. As the consequences of hypothermia are well-known, we recommend core temperature monitoring in all patients having lower extremity tourniquet placed during general anesthesia, as well as vigilant monitoring for prolonged effects of anesthetics in the postoperative period.

Baby bottle tooth decay: a concern for all mothers.

Health care professionals often inappropriately separate dental health from other health functions. Baby bottle tooth decay (BBTD) should be a concern for all professionals who work with expectant or new mothers and very young children. Research indicates that even though many mothers are aware of the etiology of the condition, they continue to allow prolonged nursing with milk or liquids other than water. Nurses can help promote good oral health for children by educating and training expectant and new mothers, children, and others who work with mothers and children in preventing BBTD.