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PubMed1987

Phencyclidine-induced head-weaving and head-twitch through interaction with 5-HT1 and 5-HT2 receptors in reserpinized rats.

Phencyclidine mainly produced head-weaving and head-twitches at doses of 5-7.5 mg/kg and of 7.5-12.5 mg/kg, respectively. Phencyclidine-induced head-twitches and head-weaving were blocked by pretreatment with ritanserin (1 mg/kg), a selective serotonin (5-HT)2 receptor antagonist and with pindolol (20 mg/kg, s.c.), a 5-HT1 receptor antagonist, respectively. In reserpine-pretreated rats, the degree of utilization of 5-HT and the number of 5-HT1 ([3H]5-HT) and 5-HT2 ([3H]ketanserin) binding sites were significantly increased compared with the figures for the vehicle-pretreated rats. The intensity of phencyclidine-induced head-weaving (at the dose of 2.5 mg/kg) and head-twitch (at the doses of 2.5 and 5 mg/kg) was significantly increased in reserpine-pretreated rats compared with that of vehicle-pretreated rats. Furthermore, in the reserpine-pretreated rats, the intensity of phencyclidine (1.25 mg/kg)-induced head-weaving and head-twitches was increased in combination with imipramine, while the intensity of phencyclidine (2.5 mg/kg)-induced head-weaving and head-twitch was decreased by pretreatment with mianserin, a non-selective 5-HT receptor antagonist. These results indicate that phencyclidine induced head-weaving by interacting with 5-HT1 receptors, indirectly after the release of 5-HT and/or with some other mechanisms and induced head-twitch by interacting with 5-HT2 receptors directly and/or indirectly.

Animals↗
PubMed1986

The effect of cross-bridge clustering and head-head competition on the mechanical response of skeletal muscle under equilibrium conditions.

The effect of cross-bridge clustering and head-head competition on the mechanical response of skeletal muscle under equilibrium conditions is considered. For this purpose, the recent multiple site equilibrium cross-bridge model of Schoenberg (Schoenberg, M., 1985, Biophys. J., 48:467-475) is extended in accordance with the formalism of T.L. Hill (1974, Prog. Biophys, Mol. Biol., 28:267-340) to consider the case where groups of independent cross-bridge heads compete with each other for binding to multiple actin sites. Cooperative behavior between heads is not allowed. Computations indicate that for the double-headed cross-bridge with two independent equivalent heads, the time course of force decay after a stretch is similar to that for the single-headed cross-bridge; that is, the rate constant for force decay is approximately equal to the cross-bridge head detachment rate constant. The results also show that the force decay after a stretch becomes slower than the detachment rate constant of a single head when cross-bridge heads bind adjacently in clusters so that competition between heads for binding to the available actin sites increases. However, if one assumes that the detachment rate constant of an unstrained head in a fiber is comparable to that of an S1 molecule in solution, this effect is not large enough to explain why some of the rate constants for force decay after a stretch in rigor, or in the presence of ATP analogues such as adenyl-5'-yl imidodiphosphate, appear to be significantly slower than the detachment rate constant of S1 from actin in solution.

Animals↗
PubMed2004

Comparison of the mechanical performance of ossiculoplasty using a prosthetic malleus-to-stapes head with a tympanic membrane-to-stapes head assembly in a human cadaveric middle ear model.

HYPOTHESIS: Ossiculoplasty using prosthetic reconstruction with a malleus assembly to the stapes head will result in better transmission of vibrations from the eardrum to the stapes footplate than reconstruction with a tympanic membrane assembly to the stapes head. Both types of reconstruction will be affected by tension of the prosthesis. BACKGROUND: Theories (and some clinical studies) that the shape of the normal tympanic membrane is important suggest that prosthetic reconstruction to the malleus performs better than reconstruction to the tympanic membrane. This has not been previously tested by directly measuring vibration responses in the human ear. Our previous work suggests that tympanic membrane assembly to the stapes head type prostheses performed best under low tension. This had not been previously tested for malleus assembly to the stapes head type prostheses. METHODS: Hydroxyapatite prostheses were used to reconstruct a missing incus defect in a fresh cadaveric human ear model. Two types of prostheses were used, one from the stapes head to the malleus (malleus assembly to the stapes head), the other from the stapes head to the tympanic membrane (tympanic membrane assembly to the stapes head). Stapes footplate center responses were measured using a laser Doppler vibrometer in response to calibrated acoustic frequency sweeps. RESULTS: Tension had a very significant effect on both types of prostheses in the lower frequencies. Loose tension was best overall. The malleus assembly to the stapes head type prostheses consistently performed better than the tympanic membrane assembly to the stapes head type prostheses when stratified for tension. CONCLUSION: Tension has a significant effect on prosthesis function. Malleus assembly to the stapes head type prostheses generally result in better transmission of vibrations to the stapes footplate than tympanic membrane assembly to the stapes head type prostheses.

Biomechanical Phenomena↗
PubMed1990

Ectopic head and foot formation in Hydra: diacylglycerol-induced increase in positional value and assistance of the head in foot formation.

In wild type Hydra magnipapillata, daily application of the protein kinase C activator diacylglycerol (DAG) evokes sprouting of periodically spaced ectopic heads along the body column and leads to loss of the ability to regenerate proximal structures including the foot. The present transplantation studies show that the appearance of ectopic heads is preceded by an early increase in the 'positional value' (P-value) or 'head activation potential' of the gastric column. Long before ectopic head structures emerge, pieces of DAG-treated tissue transplanted into the corresponding positional level of untreated hosts induce head formation instead of being integrated, whereas pieces implanted from untreated donors into DAG-treated hosts form feet. Foot formation implies a decrease in the P-value. This down-regulation is promoted through long-range assistance by the head. Thus, after termination of the DAG treatment ectopic feet are intercalated midway between the periodically spaced heads; moreover, untreated polyps onto which additional distal heads have been grafted regenerate feet faster than do one-headed polyps and may form supernumerary feet. Multiheaded animals can also be produced using two substances (K-252a and xanthate D609) that interfere with signal transduction, but the mode by which secondary heads arise is different from DAG-induced ectopic head formation. Presumably because the assistance by the parental head is impaired, buds fail to form a foot and detach and instead give rise to stable secondary body axes. It is assumed that the P-value along the body varies according to the number of cellular receptors for factors serving as intercellular signals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2000

Caries risk assessment and prevention: strategies for Head Start, Early Head Start, and WIC.

OBJECTIVES: This review updates the evidence regarding caries risk assessment for infants, toddlers, and preschool children and formulates recommendations for preventive strategies for WIC, Head Start, and Early Head Start. METHODS: Literature on caries risk assessment and preventive strategies for infants, toddlers, and preschool children were reviewed and synthesized. Recommendations for WIC, Head Start, and Early Head Start were made based on the review. RESULTS: Individual caries risk for children in WIC, Head Start, and Early Head Start should be based on: (1) previous caries experience, (2) precavity lesions, (3) visible plaque, and (4) perceived risk by examiners. Recommended preventive strategies for WIC and Head Start populations include: (1) daily toothbrushing in Head Start centers using fluoridated toothpaste; (2) fluoride varnish application to children enrolled in WIC, Head Start, and Early Head Start; (3) use of chlorhexidine gels and varnishes (following FDA approval); and (4) increased use of sealants on children with precavity pit and fissure lesions. CONCLUSIONS: Early screening, risk assessment, and preventive programs in WIC, Head Start, and Early Head Start populations hold a great deal of promise for preventing dental decay in high-risk children.

Anti-Infective Agents, Local↗
PubMed2006

Relationship between static natural head position and head position measured during walking.

INTRODUCTION: The aim of this project was to determine whether there is a statistically significant difference between the means of static and dynamic (measured during walking) measurements of head posture. METHODS: The sample consisted of 50 subjects, 25 women and 25 men, 20 to 25 years of age. None had a history of orthodontic treatment, head or neck injury, or nasal breathing problems, and none wore eyeglasses to correct vision. Static measurement of head position was recorded by using the self-balance position. Dynamic measurements of head position were made with an inclinometer device with the subject walking in a relaxed manner for 5 minutes. The data, measured in degrees, were stored in a pocket data logger. Recorded static and dynamic head posture data were transferred to a computer for analysis. The means of the measurements were statistically compared with the t test (alpha = .05). The mean walking head position was tipped forward relative to the mean static head position. RESULTS: The mean value of static position minus walking head position measurements was +4.60 degrees . The differences between the 2 recordings were statistically significant (P < .001). CONCLUSIONS: Static and walking head position measurements are not interchangeable. Therefore, it might be advisable to use the mean dynamic measurement of head position to represent natural head position for positioning when taking case records such as lateral and posteroanterior cephalograms, clinical extraoral photography, or 3-dimensional imaging.

Adult↗
PubMed1997

The influence of head position and head position change on spontaneous body posture and motility in full-term AGA and SGA newborn infants.

No consensus exists concerning the influence of head position and head position change on body posture and motility. Especially the existence of an asymmetric tonic neck reflex (ATNR) in full-term newborns is an issue of discussion. Three-hour video recordings were made of 15 full-term appropriate for gestational age (AGA) and 15 full-term small for gestational age (SGA) infants between the third and eight postnatal day. During a playback of the video recording head position, head position change and several movement patterns of the four limbs were fed into a computer using an event-detecting program. Furthermore, spontaneous head turnings were selected and body posture just before, immediately at and 1 min after the head turning were sketched. The data were analyzed concerning: (1) influence of head position on symmetry of movement of the four limbs; (2) the existence of an ATNR and ATNR-related patterns. In both AGA and SGA infants all movement patterns except hand-face and hand-mouth contact showed a symmetrical distribution, independent of head position. Furthermore, the occurrence of an ATNR following a spontaneous head turning in both AGA and SGA infants was rare. From our results it may be concluded that the ATNR is rare in full-term AGA and SGA newborns. Furthermore, this study demonstrates that head position is not a major factor influencing quantitative aspects of spontaneous motor behaviour. The results are of clinical importance as they imply that in the examination of the neurological condition of the full-term newborn infant by means of observation of spontaneous posture and motility, head position is not of major importance.

Functional Laterality↗
PubMed1997

Influence of lateral head tilting on head-shaking nystagmus.

We conducted a trial to determine whether or not head-shaking nystagmus (HSN) was influenced by lateral head tilting. Twenty-two patients with unilateral peripheral vestibular lesions were examined between July 1990 and June 1996. All of the patients were found to have horizontal HSN following horizontal head shaking in the upright head position. Eye movements were recorded by electronystagmography with the eyes open in complete darkness. Patients voluntarily tilted their heads to the lateral head positions with the assistance of the examiner as quickly as possible immediately after head shaking in the upright head position. Findings showed that monophasic horizontal HSN and the first phase of biphasic horizontal HSN were suppressed by lateral head tilting. The second phase of biphasic horizontal HSN was influenced differently by head tilting when compared with the first phase. Vertical (down-beating) components in horizontal HSN may appear in the peripheral vestibular lesions, but seem to have no definite relation to head positions.

Adult↗
PubMed1999

Independent control of head and gaze movements during head-free pursuit in humans.

1. Head and gaze movements are usually highly co-ordinated. Here we demonstrate that under certain circumstances they can be controlled independently and we investigate the role of anticipatory activity in this process. 2. In experiment 1, subjects tracked, with head and eyes, a sinusoidally moving target. Overall, head and gaze trajectories were tightly coupled. From moment to moment, however, the trajectories could be very different and head movements were significantly more variable than gaze movements. 3. Predictive head and gaze responses can be elicited by repeated presentation of an intermittently illuminated, constant velocity target. In experiment 2 this protocol elicited a build-up of anticipatory head and gaze velocity, in opposing directions, when subjects made head movements in the opposite direction to target movement whilst maintaining gaze on target. 4. In experiment 3, head and gaze movements were completely uncoupled. Subjects followed, with head and gaze, respectively, two targets moving at different, harmonically unrelated frequencies. This was possible when both targets were visual, and also when gaze followed a visual target at one frequency whilst the head was oscillated in time with an auditory tone modulated at the second frequency. 5. We conclude that these results provide evidence of a visuomotor predictive mechanism that continuously samples visual feedback information and stores it such that it can be accessed by either the eye or the head to generate anticipatory movements. This overcomes time delays in visuomotor processing and facilitates time-sharing of motor activities, making possible the performance of two tasks simultaneously.

Acoustic Stimulation↗
PubMedDate not supplied

Head injuries in snowboarders compared with head injuries in skiers. A prospective analysis of 1076 patients from 1994 to 1999 in Niigata, Japan.

We investigated snowboarding-related head injury cases and skiing-related head injury cases during five ski seasons at one resort area. There were 634 snowboarding-related head injuries and 442 skiing-related head injuries. The number of snowboarding head injuries increased rapidly over the study period. More male snowboarders than female snowboarders suffered head injuries. For both snowboarders and skiers, head injuries frequently occurred on the easy and middle slopes. Falls were the most frequent causes of injury in both groups. Jumping was a more frequent cause of injury in the snowboarders (30%) than in the skiers (2.5%). Injury to the occipital region predominated in the snowboarders as compared with the skiers. There were 49 organic lesions in 37 snowboarders and 46 organic lesions in 33 skiers. Subdural hematoma was frequent in the snowboarding head injury group, and fracture was frequent in the skiing head injury group compared with the snowboarding group (not significant). Subdural hematoma was likely to be caused by a fall rather than by a collision, and bone fracture was likely to be caused by a collision rather than by a fall. Four snowboarders and one skier died as a result of their head injuries. Our data suggest that snowboarding head injuries may be prevented by protection of the occipital region and refraining from jumping by beginners.

Accidental Falls↗
PubMedDate not supplied

Involvement of cytoplasmic free calcium in boar sperm: head-to-head agglutination induced by a cell-permeable cyclic adenosine monophosphate analog.

When boar spermatozoa are incubated in a medium designed for in vitro fertilization, many of them become agglutinated at the acrosomes. We previously reported that bicarbonate and cyclic adenosine 3',5'-monophosphate (cAMP) promote agglutination. The aim of the present study is to examine the role of cytoplasmic free Ca(2+) in boar sperm agglutination induced by a cell-permeable cAMP analogue. Spermatozoa were collected from five mature boars, washed, and resuspended in a modified Krebs-Ringer-Hepes solution lacking calcium chloride. The sperm suspensions were incubated in a water bath (38.5 degrees C) for 60 minutes and were then used to determine the percentages of head-to-head agglutinated spermatozoa. Percentages of head-to-head agglutinated spermatozoa in the samples rose significantly after incubation, from 28% to 61%-62%, after adding to the medium a cell-permeable, phosphodiesterase-resistant cAMP analogue (cBiMPS, 10 microM) or an adenylyl cyclase stimulator (sodium bicarbonate, 5 mM) plus a cell-permeable phosphodiesterase inhibitor (IBMX, 25 microM). However, the promoting effects of these reagents were blocked when spermatozoa were pretreated with a cell-permeable Ca(2+) chelator (BAPTA-AM, 25 microM), whereas the same pretreatment with a cell-impermeable Ca(2+) chelator (BAPTA, 25 microM) had almost no influence on sperm agglutination. Adding thapsigargin, a potential Ca(2+)-ATPase inhibitor, to the medium raised the percentages of agglutinated spermatozoa in a concentration-dependent manner for concentrations up to 4 microM. When 4 microM thapsigargin and 10 microM cBiMPS were examined for their effects on free Ca(2+) levels in sperm heads by using a cell-permeable Ca(2+) indicator (fluo-3/AM), the samples incubated with both or either of these reagents contained many head-to-head agglutinated cells that exhibited intense fluorescence in the heads. In control samples incubated without these reagents by contrast, most spermatozoa were free (unagglutinated) cells and characterized by almost no or only slight fluorescence in the heads. Moreover, morphological observation of Giemsa-stained preparations revealed that most agglutinated spermatozoa possessed darkly stained acrosomes, which distinguished them from acrosomereacted spermatozoa. This indicated that the sperm agglutination was not a result of the acrosome reaction. Furthermore, with indirect immunofluorescence of Ca(2+)-ATPases, the mouse monoclonal antibody to this enzyme demonstrated high affinity to the acrosomes of permeabilized spermatozoa. Based on these results, we conclude that cytoplasmic free Ca(2+) is involved in sperm head-to-head agglutination induced by a cAMP analogue.

1-Methyl-3-isobutylxanthine↗
PubMed2006

Head rotation during vertical impact predicted using initial head angle and anthropometry.

INTRODUCTION: Dynamic inertial loading to the head and neck complex, similar to what is experienced during the rocket boost phase of pilot ejection, results in diverse kinematic responses when observed in live human volunteers. The purpose of this study was to develop a predictive model of head rotation during the compressive phase of pilot ejection. METHODS: Post hoc analyses were conducted on data from two previous experimental studies. This analysis included observing 138 tests involving 27 human volunteers (both men and women) where the various kinematic responses were categorized into five modes based on the location of primary rotation and the direction of head rotation. Several statistical methods (logistic regression, linear regression, and Fisher's Exact test) were employed to evaluate the influence of independent variables, body anthropometry, and initial head angle on dependent variables head acceleration and direction of head rotation. RESULTS: Statistical results of this data indicated that initial head position and body anthropometry are significant factors with respect to head response during the compressive phase of an ejection. Two statistical tools were developed; one to assist in predicting the location of primary head rotation, and the other to predict the direction of head rotation. DISCUSSION: By using the two statistical tools together, a simplified method was developed for predicting the modes of head response to vertical impact based on initial position and anthropometry. The results of this study show the importance of initial position prior to an ejection and may assist in identifying individuals at greater risk of injury during an ejection.

Anthropometry↗
PubMed1988

[Hygienic aspects of pig's head meat. 1. Obtaining and processing pigs' heads].

Pigs's head meat is mainly obtained in specialised deboning plants and provides raw materials for the manufacture of meat products and snacks. Few data on hygiene in processing and production of pig's heads or on the bacteriological quality and tissue composition of pig's head meat have so far been published. The object of the present investigation was to supplement these data and to examine the extent to which this quality could be improved by Good Manufacturing Practices (GMP's). A total number of 11 slaughter-houses and 14 deboning plants were studied. Hygiene was assessed by two investigators on the basis of a check list. Temperatures of rooms, heads and head meat were measured. Twenty-one samples (7 x 3) were taken in each of nine deboning plants for bacteriological and histological examination. The investigations carried out in slaughter-houses showed that pig's heads were only washed in five out of eleven slaughter-houses. Cleansing and disinfection of the apparatus used in splitting the carcasses were omitted or merely carried out incidentally during slaughter. Assessment of hygiene in the deboning plants ranged from adequate to satisfactory in 13 out of 14 plants. The average aerobic colony count in Log N g-1 of pig's head meat was 6.7 +/- 0.7; this was 4.4 +/- 0.9 for counts of colony-forming units (CFU) of Enterobacteriaceae. Tonsils, mucous membranes, bone, hair and dirt were found to be present in 8, 13, 21, 39 and 9 per cent of the samples respectively. As a result of the manual cleavage of heads, relatively large bone particles (greater than 8 mm) were detected in the head meat. It is concluded that an improvement of the hygienic quality of pig's head meat can mainly be achieved by taking more care in obtaining pig's heads.

Abattoirs↗
PubMed1996

A discontinuous headful packaging model for packaging less than headful length DNA molecules by bacteriophage T4.

Bacteriophage T4 and other double-stranded DNA-containing bacteriophages package DNA by the classical headful packaging mechanism. In this mechanism, the packaging machinery cuts a DNA concatemer and packages a single unit length genome within the viral capsid. The length of the packaged DNA molecule is determined by the size of the viral capsid. Surprisingly, during large DNA cloning experiments, we observed that the in vitro phage T4 packaging system can package and transduce DNA molecules that are much smaller than the T4 headful size. We analyzed this phenomenon by using defined plasmid DNAs as substrates for in vitro packaging. The data showed that phage T4 can successfully package and transduce 4 to 29 kb plasmid DNA molecules. When two plasmid DNAs with different antibiotic markers were added to the packaging reaction mixture, transductants that are resistant to both the antibiotics were obtained, suggesting that both the plasmid DNAs are packaged within the same head. Analysis of the transducing particles by equilibrium CsCl density-gradient centrifugation showed that the particles have the same density as the wild-type phage. That the less than headful length molecules were not converted to T4 headful length prior to packaging was established by a number of independent approaches. Finally, unit length plasmid DNA molecules of appropriate size were isolated from the in vitro packaged particles. Based on these data, we propose a discontinuous headful packaging model for packaging less than headful length molecules. In this model, the packaging machinery packages the first available less than headful length DNA molecule and generates a partially full head. The partially full head then reinitiates packaging on a second DNA molecule. This process continues until the head is filled with DNA.

Bacteriophage T4↗
PubMed1983

Hydra transplantation phenomena and the mechanism of hydra head regeneration. I. Properties of the head inhibition.

Measurements were made of the "head inhibition" and the "head inhibition gradient" in Hydra. Following decapitation, the head inhibition decays with a half-time of 2-3 hr. The slope of the inhibition gradient increases about twofold when the temperature is raised from 20 to 24 degrees C; the increase (at the higher temperature) occurs with a half-time of about 1.2 hr. These results are consistent with the idea that the head inhibition and the head inhibition gradient are due to a diffusing substance, made in the head and broken down in the body of Hydra, with a half-life of about 2 hr at 20 degrees C and about 1 hr at 24 degrees C. Calculations suggest a diffusion constant of 1-3 X 10(-6) cm2/sec and a gradient range (ratio of maximum to minimum concentration) of about 2. During head regeneration, the head inhibition returns much more slowly than one would expect if its production were switched on at the time of "head determination." The slow return of the inhibition can be explained if one assumes that determination is due to the "activation" of a few cells, while the restoration of inhibition depends on the lateral expansion of the activated region. This behavior is observed in a "proportion-regulating" diffusion-reaction model proposed by Gierer and Meinhardt, 1972, Kybernetik 12, 30-39. Transplants to beheaded animals demonstrate a substantial inhibition gradient even at 6 hr after decapitation, a time at which most of the inhibitor from the original head should have decayed and no substantial amount of inhibitor is expected from the regenerated head. Experiments in which parts of a hydra's body are removed suggest that this inhibition gradient is due to the production of some inhibitor in the body, with larger amounts produced in apical portions.

Animals↗
PubMed2004

Mortality prediction of head Abbreviated Injury Score and Glasgow Coma Scale: analysis of 7,764 head injuries.

BACKGROUND: We assessed the prognostic value and limitations of Glasgow Coma Scale (GCS) and head Abbreviated Injury Score (AIS) and correlated head AIS with GCS. STUDY DESIGN: We studied 7,764 patients with head injuries. Bivariate analysis was performed to examine the relationship of GCS, head AIS, age, gender, and mechanism of injury with mortality. Stepwise logistic regression analysis was used to identify the independent risk factors associated with mortality. RESULTS: The overall mortality in the group of head injury patients with no other major extracranial injuries and no hypotension on admission was 9.3%. Logistic regression analysis identified head AIS, GCS, age, and mechanism of injury as significant independent risk factors of death. The prognostic value of GCS and head AIS was significantly affected by the mechanism of injury and the age of the patient. Patients with similar GCS or head AIS but different mechanisms of injury or ages had significantly different outcomes. The adjusted odds ratio of death in penetrating trauma was 5.2 (3.9, 7.0), p < 0.0001, and in the age group > or = 55 years the adjusted odds ratio was 3.4 (2.6, 4.6), p < 0.0001. There was no correlation between head AIS and GCS (correlation coefficient -0.31). CONCLUSIONS: Mechanism of injury and age have a major effect in the predictive value of GCS and head AIS. There is no good correlation between GCS and head AIS.

Adult↗
PubMed1999

Coagulofibrinolytic changes after isolated head injury are not different from those in trauma patients without head injury.

BACKGROUND: To test the hypothesis that tissue factor release, thrombin activation, fibrin formation, and fibrinolysis after an isolated head injury are equal to those in patients without head injury, as well as to investigate the precise time course of the coagulation and fibrinolytic abnormalities after head injury, we performed prospective and retrospective studies. METHODS AND RESULTS: In the prospective study, 5 patients with isolated head injury and 11 trauma patients without head injury took part in this study. Tissue factor antigen concentration, prothrombin fragment F1+2, thrombin antithrombin complex, fibrinopeptide A, and fibrin degradation products (D-dimer) were measured on the day of admission, and days 1, 2, 3, and 4 after admission. The levels of all five hemostatic molecular markers were markedly elevated on the day of admission, and then gradually decreased to day 4. The levels and the time course of these hemostatic markers in patients with isolated head injury were not different from those in the control patients. The same incidence of disseminated intravascular coagulation between the two groups was also observed. In the retrospective study, the records of fibrinopeptide Bbeta15-42, plasmin antiplasmin complex, plasminogen activator inhibitor-1 antigen concentration (PAI-1 antigen), and PAI-1 activity in 76 trauma patients were reviewed. On the basis of the exclusion criteria, 9 patients with isolated head injury and 30 control patients were selected for the study group. Fibrinopeptide Bbeta15-42 and plasmin antiplasmin complex markedly elevated on the day of admission, then decreased on day 1, and tended to increase to day 5. Markedly elevated PAI-1 antigen and PAI-1 activity on the day of admission significantly decreased on day 1 and recovered to the normal values on day 5. The changes of these molecular markers in patients with isolated head injury were equal to those in the control patients. CONCLUSION: We systematically elucidated the time course of coagulation and fibrinolysis after isolated head injury. We further demonstrated that changes in coagulofibrinolytic and antifibrinolytic systems in patients with isolated head injury are not different from those in patients without head injury.

Adult↗
PubMed2005

Head injuries: a study evaluating the impact of the NICE head injury guidelines.

BACKGROUND: The NICE head injury guidelines recommend a different approach in the management of head injury patients. It suggests that CT head scan should replace skull x ray (SXR) and observation/admission as the first investigation. We wished to determine the impact of NICE on SXR, CT scan, and admission on all patients with head injury presenting to the ED setting and estimate the cost effectiveness of these guidelines, which has not been quantified to date. DESIGN: Study of head injury patients presenting to two EDs before and after implementation of NICE guidelines METHODS: The rate of SXR, CT scan, and admission were determined six months before and one month after NICE implementation in both centres. The before study also looked at predicted rates had NICE been applied. This enabled predicted and actual cost effectiveness to be determined. RESULT: 1130 patients with head injury were studied in four 1 month periods (two in each centre). At the teaching hospital, the CT head scan rate more than doubled (3% to 7%), the SXR declined (37% to 4%), while the admission rate more than halved (9% to 4%). This represented a saving of 3381 pounds sterling per 100 head injury PATIENTS: greater than predicted with no adverse events. At the District General Hospital, the CT head scan rate more than quadrupled (1.4% to 9%), the SXR dropped (19 to 0.57%), while the admission rate declined (7% to 5%). This represented a saving of 290 pounds sterling per 100 head injury patients: less than predicted. CONCLUSION: The implementation of the NICE guidelines led to a two to fivefold increase in the CT head scan rate depending on the cases and baseline departmental practice. However, the reduction in SXR and admission appears to more than offset these costs without compromising patient outcomes.

Adolescent↗