Splanchnic perfusion evaluation during hemorrhage and resuscitation with gastric near-infrared spectroscopy.

OBJECTIVE: The purpose of this study was to use a prototype side-illuminating near-infrared spectroscopy (NIRS) nasogastric probe to continuously measure changes in gastric tissue oxygen saturation (Sto2) in a pig hemorrhage model. METHODS: Swine (n = 12; 6 per group) underwent laparotomy and placement of a gastric NIRS probe, jejunal tonometer, superior mesenteric artery (SMA) flow probe, and a portal vein catheter. Animals underwent hemorrhage (28 mL/kg) t = 0 to 20 minutes (where t = time). Pigs in group I were resuscitated (t = 20-40 minutes) with lactated Ringer's solution (84 mL/kg), whereas group II had no resuscitation. RESULTS: A significant decrease in mean arterial pressure and SMA flow was observed after hemorrhage. SMA flow significantly correlated in group I with both NIRS Sto2 (r = 0.58, p = 0.0001) and regional CO2 (r = -0.54, p = 0.0001). In group II, superior mesenteric flow correlated with NIRS Sto2 (r = 0.30, p = 0.03), but not regional CO2 (r = -0.23, p = 0.09). CONCLUSION: Direct measurement of tissue oxygen saturation with a prototype side-illuminating near-infrared spectroscopy gastric probe appeared to rapidly reflect changes in splanchnic perfusion.

Realities of craniofacial growth modification.

Facial growth modification can be an effective method of resolving skeletal discrepancies. There still is much controversy regarding our understanding of the nature and extent of skeletal orthopedic change possible in individual patients and the most effective appliances and timing of such treatment. In the treatment of class II patients, growth modification can lead to an improvement, if not complete correction of the class II malocclusion. Although two-phase treatment with an early first prepubertal phase can be effective, a later single-phase approach during early puberty seems to be equally effective. Certainly, before surgical correction of the mild to moderate skeletal class II problem in a growing patient is considered, an orthopedic phase of treatment prior to the pubertal growth spurt is an appropriate first step. Skeletal class III patients with a maxillary deficiency stand to gain significant benefits from early orthopedic treatment. However, such therapy may produce more favorable changes for older children and adolescents than previously thought. Nevertheless, orthopedic correction of the mild to moderate skeletal class III should be accompanied by regular progress evaluations to avoid creating significant dental compensations in the face with little skeletal change that ultimately requires surgery anyway. Skeletal class III patients with mandibular excess and/or vertical excess are poor candidates for growth modification. Orthopedic palatal expansion appears to be effective and stable at any time prior to late puberty, a stage of development when ossification of the maxillary sutures is more advanced. Consequently, the timing for expansion may be better determined by the specific needs of each patient. A functional shift resulting from a crossbite is optimally corrected early, so that asymmetric growth of the mandible can be reduced or even prevented. Postpubertal orthopedic expansion is likely to result in bone bending, which will reverse itself over time, potentially leaving periodontal compromise of the maxillary posterior teeth. Therefore, surgically assisted expansion should be considered in such cases. Vertical maxillary excess is challenging to treat with growth modification. The combination of interocclusal acrylic bite blocks combined with a high-pull headgear presently appears to be the best means available. Unfortunately, this treatment has limited success, it must be continued over many years owing to the long-term nature of vertical growth, and it is counterproductive in achieving a balanced sagittal jaw relationship in class I or class III patients with vertical excess. Future research will permit us to have a greater understanding of the nature and extent of facial growth modification possible in individual patients and the optimal appliances and timing of treatment to achieve the best outcome. The development of intraoral osseointegrated attachments such as implants and onplants hold promise for a future means of dissipating orthopedic forces to prevent unwanted dentoalveolar changes that presently occur with our tooth-borne appliances. Analogous attachments presently are undergoing clinical testing for surgically assisted orthopedic movements associated with distraction osteogenesis.

Dietary olive oil enhances murine lymphocyte calcium uptake.

BACKGROUND: Dietary lipids enhance immune function and improve outcome from injury or infection in animal models. We tested the hypothesis that amount, type, or both, of dietary lipid increases intracellular calcium concentration, a surrogate for lymphocyte activation. METHODS: Mice were fed 2 weeks on semipurified diets with 5% (by weight [w/w]), 10% (w/w), or 20% (w/w) dietary fat consisting of coconut, olive, safflower, or linseed oil. Changes in intracellular calcium concentration after mitogen stimulation of splenic lymphocytes was estimated by using flow cytometry. RESULTS: Olive oil diets increase intracellular calcium concentration after concanavalin A, lipopolysaccharide, and CD3 stimulation. On the other hand, linseed oil (which is high in omega-3 fatty acids, which have been shown in other studies to enhance immune function) depresses intracellular calcium levels. The amount of dietary fat had no effect on intracellular calcium. CONCLUSION: Olive oil merits further study in the application of nutritional pharmacology to immunomodulation of the critically injured, because it may enhance lymphocyte function.

High-fat diets suppress CD3 and CD25 expression on the surface of murine lymphocytes.

To determine the effects of dietary fats on surface antigen expression, we tested the effects of amount and type of dietary fat on murine lymphocytes. Mice were fed diets with 12 en%, 23 en%, or 47 en% fat containing coconut, olive, safflower, or linseed oil. After 2 wk of ad libitum feeding, the mice were killed and splenic lymphocytes were harvested. Lymphocytes were incubated with fluorescent-tagged monoclonal antibodies and assayed for mean and total surface expression using flow cytometry. Our results show that high-fat (47 en%) diets suppress expression of CD3 and CD25 antigens. We also found that linseed-oil diets suppress expression of CD11a but enhance expression of CD25 antigens. Both CD3 and CD25 are critical for lymphocyte activation, and we conclude that immunosuppression associated with high-fat diets may be associated with suppression of these surface antigens.

Pharmacokinetics and burn eschar penetration of intravenous ciprofloxacin in patients with major thermal injuries.

Adequate penetration of antibiotics into burn tissue and maintenance of effective serum levels are essential for the treatment of patients sustaining major thermal injuries. The pharmacokinetics and burn eschar penetration of intravenous ciprofloxacin were determined in 12 critically ill patients with burn injuries. Mean age for the 12 patients was 45 +/- 17 (range 25-82 years), total body surface area burned (TBSAB) = 38 +/- 15% and Acute Physiology and Chronic Health Evaluation (APACHE) II score = 8 +/- 6. Patients received recommended doses of ciprofloxacin, 400 mg q12h iv, for three doses beginning 72 h post-burn. Serum concentrations were measured at t = 0, 0.25, 0.5, 0.75, 1.0, 1.25, 1.5, 2.0, 4.0 and 12.0 h after the first and third doses. Burn eschar biopsies were obtained after the third ciprofloxacin dose. Three of these 12 patients (25%) manifested later signs of clinical sepsis (TBSAB = 61 +/- 6% and APACHE II score = 11 +/- 3) and underwent a second infusion of three doses of intravenous ciprofloxacin, blood sampling and eschar biopsy. Serum and eschar concentrations were determined by high performance liquid chromatography. Serum ciprofloxacin concentrations were comparable to those of normal volunteers (C(max) = 4.0 +/- 1 mg/L and AUC = 11.4 +/- 2 mg.h/L) during the immediate post-burn period after dose 1 (C(max1) = 4.8 +/- 3 mg/L and AUC(0-12) = 12.5 +/- 7 mg. h/L) and dose 3 (C(max3) = 4.9 +/- 2 mg/L and AUC(24-36) = 17.5 +/- 11 mg.h/L). Mean burn eschar concentration during the 72 h post-burn was significantly lower than that found during clinical sepsis (18 +/- 17 compared with 41.3 +/- 54 microg/g; P < 0.05 by t test). Similar serum concentrations were achieved in patients with clinical sepsis (C(max1) = 4.2 +/- 0.2 mg/L and AUC(0-12) = 15.0 +/- 3 mg. h/L; C(max3) = 5.0 +/- 1 mg/L and AUC(24-36) = 22.8 +/- 9 mg.h/L). A positive correlation between burn eschar concentrations and C(max) (r = 0.71, r(2) = 0.51, P = 0.01) was found by linear regression analysis. A C(max)/MIC ratio > 10 (MIC = 0.5 mg/L) and an AUC/MIC ratio > 100 SIT(-1).h (serum inhibitory titre) (MIC = 0.125 mg/L) were achieved. High burn eschar concentrations and serum levels, similar to those found in normal volunteers, can be achieved after intravenous ciprofloxacin infusion in critically ill burns patients.

Screening for HIV, HBV and HCV markers among drug users in treatment in rural south-east England.

BACKGROUND: This study was designed as an opportunistic screening to estimate the prevalence of blood-borne viral infection among drug users in treatment in the rural population and to investigate related risk factors and use of general health services. METHODS: A total of 102 patients aged 18 years and over (78 male, 24 female) with problematic self-reported drug use, recruited between 1 February 1996 and 31 January 1997, in a mixed urban-rural population in south-east England, were interviewed for information on socio-demographic status, drug use history, HIV-related risk behaviours, hepatitis B vaccination, general practice consultations, and use of A&E departments and medical out-patient clinics. Diagnostic testing was offered to all patients for anti-HIV-1, anti-HBc, HBsAg and anti-HCV. RESULTS: The mean age at onset of illicit drug use for the entire sample was 15.33 (SD 3.36) years; 3.7 per cent (1/27), 20.4 per cent (18/88), and 55.8 per cent (48/86) had antibodies to HIV-1, HBc and HCV, respectively; 1.1 per cent (1/88) tested positive for HBsAg indicative of a carrier state. All 18 patients anti-HBc seropositive were male (p = 0.009). There was no gender difference for anti-HCV serological status. The proportion of town residents and village dwellers seropositive for anti-HBc and anti-HCV did not differ significantly. Patient's age at interview, age at onset of opioid use and duration of opioid use showed a significant association with anti-HBc and anti-HCV serological status. The proportion directly sharing injecting equipment was too small for rigorous statistical analysis; however, indirect sharing involving cooking equipment and frontloading rituals achieved statistical significance. Anti-HBc serological status showed a significant association with vaginal intercourse without a condom (p = 0.03); none of the sexual risk behaviour variables revealed any significant association with HCV infection. Although only one-third of the sample consented to HIV antibody test, consenting and non-consenting groups did not differ significantly except on one variable: having a drug-using sexual partner (chi2 = 5.6167; p = 0.017). Serum aspartate amino transferase and gamma-glutamyl transpeptidase concentrations were raised above the upper limit in 23 (25.7 per cent) of the 89 patients who gave blood specimens; 41.2 per cent (42/102) were referred to treatment by their general practitioners. There was no significant relationship between HBV and HCV serological status and general practice consultations. Only eight (7.8 per cent) had received hepatitis B vaccination, and although 48 (47.1 per cent) had in the preceding 12 months used A&E departments, only seven (6.2 per cent) had been seen in medical out-patient clinics. CONCLUSION: In this study the prevalence of HIV, HBV and HCV in the rural population is as high as has been reported for inner cities. The poor uptake of hepatitis B vaccination among drug users, their poor response to HIV antibody test and poor health service utilization suggest the need for an urgent appraisal of service provision and a review of prevention and treatment strategies.

Prevalence of temporomandibular disorders (TMD) in children based on physical signs.

Temporomandibular disorders (TMD) are related to the function and integrity of the masticatory system with restricted jaw movement and/or joint clicking or crepitus, for example, dominating the clinical signs of these disorders. The prevalence of TMD signs was examined in non-patient children ages six to twelve (1994 n = 185, 1995 n = 237) by four examiners using standardized techniques. Of significance was the finding that 7.3 percent of the 1994 children had audible joint sounds, while the 1995 examination reported 3 percent. Statistically significant relationships (p < 0.05) between the ages of the subjects and measurements of overbite (p < 0.0001), overjet (p < 0.01), and clicking (p < 0.005) were calculated from the 1994 data, while significant correlations for overbite (p < 0.001) and overjet (p < 0.01), but not clicking were found in the 1995 examination. One study of four- to six-year-old nonpatients reported a higher occurrence of joint sounds (48 percent). This disparity indicates a possible need for standardization of examination techniques specifically targeting joint sounds and their role in TM disorders.

Involvement of CD44 and the cytoskeletal linker protein ankyrin in human neutrophil bacterial phagocytosis.

The leukocyte CD44 and CD45 cell surface receptors are associated via the linker proteins ankyrin and fodrin with the cytoskeleton, which itself is important in immune cell functions such as adherence, chemotaxis, and phagocytosis. The effects of rat antihuman CD44 and CD45 monoclonal antibodies on phagocytosis of fluoresceinated heat-killed Staphylococcus aureus 502A by normal human neutrophils (PMNs) during 2 hr incubation in RPMI-1640 was studied via flow cytometry and confocal microscopy. Flow cytometry was performed using an excitation wavelength of 488 nm, fluorescence being measured at 515-560 nm on 50,000 PMNs per sample. Confocal microscopy was performed on samples after further incubation with rhodamine-conjugated antiankyrin. Anti-CD44 resulted in an increase of 27-31% compared to control (P = 0.004) in the proportion of PMNs fluorescing, an increase of 17-24% (P = 0.001) in mean intracellular fluorescence per PMN, and an increase in total PMN fluorescence of 50-58% compared to control (P < 0.001). In contrast, anti-CD45 had little effect on phagocytosis. Colchicine (a microtubule-disrupting agent) enhanced, whereas cytochalasin-D (a microfilament inhibitor) inhibited bacterial phagocytosis; cytochalasin-D completely abrogated the effect of anti-CD44 on this PMN function. Hyaluronic acid augmented phagocytosis by an increment similar to that observed with anti-CD44. Two-color flow cytometry and confocal microscopy demonstrated that ankyrin always colocalized with ingested fluorescein isothiocyanate (FITC)-labeled bacteria. These data strongly suggest that CD44 is involved in bacterial phagocytosis, provide further evidence of CD44 receptor linkage to cytoskeletal elements in human leukocytes, and suggest that ankyrin has a significant role in the transport of phagosomes.

The influence of growth hormone (rhGH) therapy on tooth formation in idiopathic short statured children.

The purpose of this preliminary study was to evaluate tooth formation in children with idiopathic short stature, before and during treatment with recombinant growth hormone (rhGH). Twenty-nine short-statured children ages 6 to 13 years were assigned into two treatment groups, an "experimental" group (n = 18), which received rhGH, and a "control" group (n = 11), which was observed for 1 year before commencing rhGH treatment. Clinical and radiographic records were obtained at the initial, year 1, and year 2 visits. Tooth formation and stature were assessed by calculating Z-scores, appropriate for the age and gender of each child. Delta-Z scores, which measure the change in Z-score over time, were also calculated between annual visits. Height was measured and recorded every 3 months, and Z-score statural norms for age and gender were derived from the 1977 National Center for Health Services national probability sampling. Tooth formation standards were derived from Moorrees et al. A matched control sample for tooth development was derived from untreated children. Tooth formation was initially delayed although the degree of reduction in stature exceeded the initial degree of delay in tooth formation. During this 2-year study, rhGH therapy had a significant influence on acceleration or gain in stature, but did not have a significant influence on tooth formation.

Changes in the nasal and labial soft tissues after surgical repositioning of the maxilla.

Accurate prediction of postsurgical function and esthetics of the nose and upper lip requires an understanding of the relationship between maxillary surgical movement and soft tissue change. Thirty-two patients underwent Le Fort I osteotomies, some with concomitant mandibular procedures. Preoperative, postoperative, and 1-year postsurgical data derived from cephalometric and nasolabial cast analysis were compared to assess skeletodental changes, soft tissue changes, and stability. A multiple stepwise regression (including age, gender, alar cinch suture, V-Y closure, and contouring of the anterior nasal spine as variables) indicated that accurate prediction equations could be formulated, particularly if the patients were grouped by vector-specific maxillary movements. In general, the base of the nose widened in all patients regardless of the vector of surgical maxillary movement. An associated shortening of the nose was found. The nasolabial angle decreased or remained constant in most patients. The upper lip widened and lengthened at the philtral columns. Narrow noses widened more than did broad noses and alar cinch suturing widened the alar base even more. Results indicated that soft tissue changes associated with maxillary surgery may be more affected by the position of the soft tissue incision and methods used in closure than by the surgically induced hard tissue change.

The role of Eh, pH and iron in the bactericidal power of human plasma.

The bactericidal power of fresh human plasma against Klebsiella pneumoniae and Escherichia coli was extremely sensitive to changes in Eh and pH. At a high Eh (approx. +200 mV) the bacteria were destroyed, but rapid regrowth occurred when the Eh was lowered to approx. -400 mV. Abolition of the bactericidal effect was also produced by adding ferric iron at a high Eh (approx. +200 mV). Lowering the pH to 6.50 reduced or prevented the bactericidal effect. These results are probably related to the availability of iron for bacterial growth, and could be important for understanding the development of infection in injured or diseased tissue.

Evaluation of the dermal effects of cast padding in coaptation casts on dogs.

Three configurations of cast padding and no cast padding were evaluated for their effects on skin in dogs. Padding was placed over bony prominences, between bony prominences, and over both areas for full-length padding under short-limb walking casts applied to 1 pelvic limb of Greyhounds. Evaluations were performed by pressure measurement over the calcaneal tuberosity, measurement of skin thromboxane B2 (TxB2) concentrations in skin over bony prominences, and measurement of plasma TxB2 concentrations. Pressure studies were performed to evaluate cutaneous pressures related to no cast padding and various configurations of cast padding. Concentrations of TxB2 in the skin were determined to evaluate the skin inflammatory effects of no padding and the padding configurations, and TxB2 concentrations in the plasma were analyzed to ascertain whether they could be used to predict impending dermal pressure lesions. Flexion of casted limbs revealed the greatest pressure over the calcaneal tuberosity with full-length cast padding. This was followed in decreasing order by no cast padding, padding over the prominences, and padding between the prominences. Compared with all other bony prominences and padding configurations, TxB2 skin concentrations were significantly higher over the calcaneal tuberosity when no padding was used and over the lateral base of metatarsal V when padding was placed between the prominences. Over the calcaneal tuberosity, this was attributed to the sharpness of the prominence and its potential for movement. This high TxB2 concentration corresponded to the high pressure found in the pressure studies. Over the lateral base of metatarsal V, the increase in TxB2 concentration was related to the mass of the prominence and the tendency for localized padding to settle around the area.(ABSTRACT TRUNCATED AT 250 WORDS)

Orthodontic adjunctive treatment in fixed prosthodontics.

The purpose of this article has been to increase the restorative dentist's appreciation for the rationale justifying preprosthodontic orthodontic treatment. It has not been intended to identify all the specific indications for the use of orthodontic treatment to enhance prosthodontic treatment nor has it been intended as a reference to assist the restorative dentist in placing and using orthodontic appliances. Figure 12 illustrates a typical case in which the combination of orthodontic and prosthodontic treatment resulted in a more favorable outcome than prosthodontic treatment alone. When planning prosthodontic treatment, the dentist should embrace a dynamic view of tooth position and determine whether restorative treatment can be enhanced by tooth movement. Improved tooth position can eliminate potentially pathologic occlusion and create a healthier periodontal environment that is easier to maintain. In addition, it permits the dentist to place restorations that often require less natural tooth reduction during preparation, and that are more esthetic, functional, stable, and durable. Orthodontic treatment that accomplishes these benefits may be limited to a partial fixed appliance localized to one segment of an arch or require a more extensive fixed appliance. Much of this treatment can be accomplished by the interested restorative dentist. Addressing more comprehensive orthodontic problems in patients requiring prosthodontic care is best managed through a restorative dentist and orthodontist team approach to treatment.

Hemochromatosis, iron and septicemia caused by Vibrio vulnificus.

Vibrio vulnificus is killed by normal human blood but grows rapidly in blood from patients with hemochromatosis. It also grows in normal blood if the saturation of the transferrin is increased or if hematin, which contains iron, is added. It is suggested that the increased availability of iron in the blood of patients with chronic iron overload is responsible for their enhanced susceptibility to infection with V vulnificus.

Sensitivity and specificity of diagnostic tests for impaired nasal respiration.

Diagnostic tests are imperfect and vary in their sensitivity and specificity. The degree of imprecision may be calculated to yield probability estimates of accuracy for both the positive and negative predictions of tests under various conditions. Such information enables clinicians to decide whether to accept or reject test results or the tests themselves. Two pilot studies are reported to establish the diagnostic potential of cephalometric measurements and nasal resistance values for the identification of upper airway impairment. A linear estimate of adenoid size and an area index of adenoid encroachment in the nasopharynx were evaluated as diagnostic tests for increased nasal resistance. The sensitivity of the tests was 31.8% and 18.2%, while specificity was calculated at 83.3% and 66.6%, respectively. In the second study, nasal resistance was evaluated as a test to identify persons whose respiratory mode was equal to or less than 75% nasal airflow. At a NRz value of 5.0 cm H2O per liter per second, the sensitivity of this test was 41.2% and the specificity was 84.0%; with the critical value of NRz at 3.5 H2O per liter per second, the sensitivity was 64.7% and the specificity was reduced to 60.0%. The results suggest that these tests are too imprecise for the reliable identification of either those who might benefit from treatment or those for whom treatment is unlikely to yield benefits.

The bactericidal power of the blood and plasma of patients with burns.

Patients with burns are unusually susceptible to bacterial infections, but so far there is no satisfactory explanation for this lack of resistance. Since resistance to infection involves many different mechanisms, examination of individual components of the immune system may not sufficiently explain the underlying reasons for increased susceptibility. The use of whole blood for antibacterial tests has the advantage that all the immune systems present in that fluid compartment can take part in the bactericidal effect. Tests with Klebsiella pneumoniae and Staphylococcus aureus showed no evidence that the bactericidal power of the blood and plasma of patients with burns was less than that of normal control plasma. This suggests that the solution to the problem of increased susceptibility to infection in patients with burns does not lie with the blood but must be looked for elsewhere.

Bacterial virulence and host selection: bacteria "select" patients to infect.

A clinically lethal strain of Pseudomonas aeruginosa was tested and its growth patterns in normal plasma and in normal whole blood clotted with thrombin were compared. Two stock cultures were used; one was maintained in liquid nitrogen and one was passed from plate to plate 24 times on blood agar plates at room temperature. The results showed that plasma alone and whole blood controlled the growth of a clinically pathogenic strain of P. aeruginosa consistently and uniquely for each donor, dependent on size of inoculum, length of incubation, and means by which the culture was maintained. The changing virulence of an organism and its unique growth patterns in different individuals' plasma and whole blood may explain why patients exposed to the same organisms within the same environment vary in susceptibility to clinical infection.

The effects of maxillary surgery on nasal respiration.

Le Fort I osteotomies frequently involve impaction of the maxilla into the nasal cavity, potentially affecting nasal form. It has been speculated that a concomitant change in nasal function may occur. The purpose of this study was to determine if there is an association between maxillary position and nasal function and to evaluate the influence of Le Fort I surgery on nasal function. Presurgical and postsurgical nasal resistance and percent nasal respiration were compared in 36 patients. Results indicated a mean change in nasal resistance 1 year after surgery, but mean percent nasal respiration did not change significantly. No prediction could be made for any patient relative to the effect of maxillary surgery on the nasal function parameters. No consistent association could be found between the amount or direction of maxillary surgical movement or the position of the maxilla and nasal respiration.

External nasal morphology and respiratory function.

Clinicians have been known to characterize nasal respiratory function on the basis of subjective appraisal of external facial morphology. Certain nasal morphologic features have been assumed to be associated with impaired nasal function. The purpose of this study was to develop measures of anterior external nasal morphology and to determine whether any of these measures correlate with nasal function. Nasal casts were produced from impressions of 60 postpubertal white subjects from which four measures were made to characterize nasal morphology: (1) nasal base shape, (2) minimum nasal orifice width, (3) nasal orifice shape, and (4) nasal orifice area. Nasal function was evaluated by measuring nasal airway resistance by means of posterior rhinomanometry and by measuring the air respired nasally and orally by means of the simultaneous nasal and oral respirometric technique. No significant correlations were found between external nasal morphology and nasorespiratory function. These findings underscore the necessity of avoiding assumptions about breathing function on the basis of clinical appraisal of external nasal form.

Higher order multiple births: natural wonder or failure of therapy?

Data of 601 families with triplets and higher multiples have been collected. Since about nine years the number of higher-order births has been increasing enormously. The average pregnancy duration and the average birthweight of these mostly premature children have been declining from year to year. Despite the progress in neonatology, the death rate and the rate of handicapped children is very high. To prevent such disastrous outcomes, treatments for infertility should be performed only by physicians in centers with strong controls. Selective abortions are no regular solution to the problem of higher multiple gestation.