Acute ischemic cerebral infarct: prospective serial observations by magnetic resonance imaging]

To determine for what deformity and utility the computer-generated acrylic (CGA) skull replica has the greatest value, we analyzed retrospectively a consecutive series of patients with craniomaxillofacial deformities (N = 54) whose treatment involved the utilization of CGA skull replicas. Application of the CGA skull replica was divided retrospectively into four groups: (1) use as an aid for preoperative analysis of osseous deformity, (2) use as material for preoperative surgical simulation, (3) use as a navigational aid during an operation, and (4) use as a negative template. Based on the aspects of these utilizations, we evaluated for what deformity the CGA skull replica was useful. Analysis of the data led us to conclude the following. First, the CGA skull replica is a valuable tool in craniomaxillofacial surgery, especially for patients with asymmetrical deformities and delicate convexities and concavities of the skull surface. Second, the largest function that CGA skull replicas can satisfy is standardization of craniomaxillofacial surgery. In carrying out preoperative surgical simulation utilizing a replica, drawing osteotomy lines on it, sterilizing it, and then bringing it to the operating table for consultation whenever required during an operation, we are able to proceed with greater precision and speed than if it was not available.     

The management of extensive tumours of the scalp

Though tumours of the scalp and skull are not very common certain severe and extensive forms are associated frequently with intracranial propagation and therefore their reconstruction represents often a major problem requiring the use of a series of surgical methods. Their treatment requires the use of expanders, local flaps, pedicled cutaneous and musculocutaneous flaps, as well as free flaps. This report deals with 10 patients with localized extensive tumours larger than 120 cm2 within the region of the scalp and skull subjected to various reconstruction procedures. The applied surgical techniques are discussed and attention is devoted also to the involvement of bone in the above mentioned localization as well as to the problems associated with these lesions.     

Microcirculatory bed of the rat ovary in health and under laser irradiation

Personal clinical observations during the recent years allow the authors to confirm the indisputable value of surgical experience got during the Great Patriotic War (1941-1945) and in particular, the "fourfold" scheme proposed by V. I. Voiachek for the diagnosis and treatment of blind gunshot wounds to the skull base. Computed tomography considerably increases the probability of detection of the exact localization of foreign bodies in complex anatomical structures of the skull and thus facilitates choosing the most rational surgical management. The use of the electro-optical transducer for the extraction of foreign bodies from almost inaccessible areas of the skull base decreases the risk of operation.     

Diseases of the skull in pre-Columbian South American mummies

OBJECTIVE: The majority of paleopathological investigations focus on the study of the skull. This is because the skull is the most frequently preserved part of the human body recovered from archaeological excavations. From studying the skull, a variety of information can be obtained regarding the individual, such as sex, age, nutritional status, and other disease processes, if present. METHODS: This study represents the examination of more than 700 human skulls recovered from archaeological excavations from the Andean region of southern Peru and northern Chile and dating back more than 8000 years. RESULTS: A variety of skull abnormalities were encountered. The nonmetric variables of Huschke's foramina and palatine tori were common. Cranial deformation was observed in more than 85% of the cases. There were two cases of sagittal synostosis. Iron deficiency anemia resulting in porotic hyperostosis of the skull was evident in certain cultures. Exostoses of the external auditory canal resulting from chronic otitis was evident only among coastal populations. One skull demonstrated a periostitis consistent with Treponema infection. Trephination was encountered only in the skulls from Peru. Fifty-four cases of skull fractures were observed, half of which showed evidence of healing. Finally, only two cases of neoplastic skull lesions were encountered. CONCLUSION: The study of the human skull alone provides a large amount of information regarding the health and diseases of ancient populations.     

Cost finding in the diagnostic imaging service

Antibiotic prophylaxis after basilar skull fractures remains controversial. Previous studies have not clearly delineated the utility of prophylactic antibiotics in this setting. We undertook this study to determine if antibiotic prophylaxis after basilar skull fractures prevented meningitis. We performed a formal systematic review of previously published studies after a computerized search with use of the MEDLINE data base (1970-1996). Fourteen studies were identified, and 12 studies met the criteria for inclusion. Study design and quality were assessed by two independent investigators with use of a predetermined protocol. A total of 1,241 patients with basilar skull fractures were included; 719 patients received antibiotics, and 522 patients did not receive antibiotics. Overall results suggest that antibiotic prophylaxis did not prevent meningitis among patients with basilar skull fractures (odds ratio [OR] = 1.15; 95% confidence interval [CI] = 0.68-1.94; P = .678). Patients with basilar skull fractures and cerebrospinal fluid leakage were analyzed separately (OR = 1.34; 95% CI = 0.75-2.41; P = .358), as were children (OR = 1.04; 95% CI = 0.07-14.90; P = 1.000). Antibiotic prophylaxis after basilar skull fractures does not appear to decrease the risk of meningitis.     

预焙铝电解槽早期槽帮的建立和后期的维护

论述了预焙铝电解槽槽帮建立的意义；着重讲述了240kA预焙铝电解槽早期槽帮在高分子比、高温条件下的建立，以及后期在低温、低分子条件下的维护和生产实践。     

Unusual gunshot injuries

Ectopic meningioma outside the skull and spinal column is uncommon. We report a cutaneous meningioma of the scalp in a 77-year-old man. A review of types and their management options are discussed. We also highlight that in certain carefully selected cases, these lesions can be treated conservatively.     

Molecular cloning, tissue distribution, and hormonal control in the ovary of Cx41 mRNA, a novel Xenopus connexin gene transcript

Infrared images of the skull surface were obtained in urethane-anesthetized rats and gerbils before, during and after mechanical stimulation of the face and mystacial vibrissae on one side. Areas of increased temperature on the skull, localized mainly over the face area of the primary somatosensory cortex contralateral to the side of stimulation, appeared within 4-5 s after the onset of stimulation. Rarely, such temperature change was recorded bilaterally. Temperatures did not remain high on the intact skull in rats, but fell to baseline within minutes after stimulus onset regardless of stimulus duration. In rats in which the skull had been thinned and in gerbils with intact skull, temperatures remained elevated during the course of stimulation. We were unable to resolve the activation of individual vibrissae.     

冶炼钒钛磁铁矿高炉的铜冷却壁挂渣分析

建立高炉铜冷却壁三维传热模型,利用有限元软件ANSYS进行稳态传热分析,研究了钒钛磁铁矿冶炼时挂渣特点。分析结果表明,由于含钒钛高炉渣铁珠含量高,使渣皮显著增厚导致渣皮稳定性下降。将铜冷却壁热电偶测量点温度控制在60～80℃,可以提高渣皮稳定性,保证铜冷却壁安全工作。在现有工艺条件下,把水速从2.3 m/s降低到1.5 m/s对挂渣影响很小。     

Intrauterine spontaneous depression of fetal skull: a case report and review of literature

Intrauterine depression of fetal skull, with or without fracture, unassociated with any known trauma during pregnancy or delivery, is extremely rare in Western countries though not so rare in Africa among African women. Usually fetal skull depression is caused by forceps or digital pressure of the obstetrician during manual rotation. Forty such cases are reported in the literature-nine in Western countries and the remaining 31 over a period of three years at Harare Hospital Maternity Centre, Salisbury, Rhodesia, Africa. There, an incidence of one in 4,000 deliveries was observed among the African women but none in 6,000 deliveries of European women during the same period at a nearby hospital. The presentation of this paper is made in view of the rarity of intrauterine spontaneous fetal skull depression in Western countries and the not so infrequent occurrence in African and possibly other developing countries and because of the persistent controversy about the treatment of this condition.     

Modern imaging of craniofacial malformations

Due to progress in the field of medical imaging of craniofacial malformations, the place of these investigations in the assessment of these abnormalities needs to be revised. 3D CT scan currently remains the fundamental element of the assessment by providing a truly anatomical dissection of each bone. In the field of craniostenoses, the study of the base of the skull has allowed a new assessment of lesions of skull base and craniofacial sutures and the resulting skeletal deformities: they provide restrospective justification for an extensive approach to the surgery of this group of malformations and a basis for reflection concerning extension to direct skull base surgery. Craniofacial clefts constitute a heterogeneous groupe of anomalies in which Tessier's concepts have allowed a methodical approach. 3D CT allows better definition of certain subgroups of malformations within this group (midfacial clefts) and provides a clearer understanding of the skeletal defects of maxillary clefts, especially in the laterofacial region. This imaging is currently undergoing rapid development. Improvement of 3D CT scanning techniques (direct 3D image acquisition, improvement of the images obtained), development and combination of 3D MRI, after being superimposed onto the skeletal image, will allow total dissection of the malformation. Development of 3D cephalometric analysis techniques and growth analysis software will allow really predictive "image-assisted surgery". Finally, antenatal imaging (B-mode and 3D ultrasonography) makes a considerable contribution to this field of anomalies by allowing the diagnosis of serious or severely disabling anomalies and by elucidating the antenatal development of certain anomalies (especially craniostenoses) and their consequences.     

Superimposed holographic image-guided neurosurgery. Technical note

Computerized tomography scanning-derived narrow band reflection holograms of patients undergoing craniofacial procedures were created to evaluate the applicability of superimposing these three-dimensional images (3-D) on the operative field during neurological surgery. These sterilized radiological holograms were positioned over the surgical site by using bone sutures as registration points between the skull and the 3-D image to serve as a visual template between the patient and surgeon. Surgeries were then performed with the surgeon looking through the radiological hologram at the patient. Holograms were accurate to within 2 mm (plus or minus) of the actual calvarial anatomy. The use of the holographic image as a visual guide during surgery eliminated intraoperative guesswork or free-handed contouring. To the author's knowledge, this is the first report of the superimposed holographic image used in situ during surgery.     

Can skull morphology be used to predict ecological relationships between bat species? A test using two cryptic species of pipistrelle

Can ecological relationships between bat species be predicted largely on the basis of morphology? This question was addressed by investigating skull morphology of two cryptic species of the pipistrelle bat. Since 45 Pipistrellus pipistrellus apparently eats larger prey than 55 P. pipistrellus, we predicted that it would have a larger overall skull size, a larger dentary apparatus, and a larger gape. To test these predictions, variables were measured from skulls of the two cryptic species, and comparisons made between them. In accordance with our predictions, overall skull size was larger in 45 P. pipistrellus than in 55 P. pipistrellus, and 45 P. pipistrellus had a longer lower jaw and the distance between the jaws at maximum gape was larger. In addition, 45 P. pipistrellus had longer upper canines, which may allow it to pierce harder prey items than 55 P. pipistrellus. Only some aspects of dietary differences between the two cryptic species could be explained by differences in skull morphology, and we suggest that empirical data, at least on diet and habitat use, are also required to explain mechanisms of resource partitioning among species in bat communities.     

Bacteriological evaluation of a down-draught necropsy table ventilation system

AIMS: To evaluate the microbiological efficacy of a down-draught necropsy table ventilation system (which surrounds the cadaver with a "curtain" of air under continuous extraction) during post mortem procedures. METHODS: Air sampling was carried out both in the presence and absence of staff and cadaver and during a full post mortem procedure, with functioning and non-functioning table air extraction. The penetration of the air "curtain" was also examined during the use of an oscillating bone saw by means of a tracer organism, Bacillus subtilis var niger, painted on to the skull. RESULTS: There was little difference between bacterial counts obtained in the presence of staff only, staff plus cadaver, or during a post mortem examination. With all counts obtained, however, there was a two to three-fold reduction when the ventilation was in operation compared with when the extract duct was occluded. Using the tracer organism, a two to three log reduction in counts was shown when the "curtain" was in operation during the use of the oscillating bone saw. CONCLUSIONS: These results suggest that the system provides potential protection for post mortem room staff against airborne infections.     

A new method of acrylic cranioplasty

BACKGROUND: Previous acrylic cranioplasty techniques have relied on wire or suture fixation of the acrylic to the skull. A new methyl methacrylate cranioplasty technique, using acrylic with titanium plating, is described. METHODS: Titanium plates were bent into a "Z" shape and attached to the skull at the perimeter of the skull defect, extending into the defect. The acrylic was then poured into the defect and held in place during setting with a sheet of plastic. The plates are thereby embedded in the acrylic. RESULTS: Standard methyl methacrylate and titanium plates and screws were used to perform a new method of cranioplasty. CONCLUSIONS: A rigid, form-fitting, aesthetic construct can be easily and quickly created. This technique also offers the benefit of allowing secondary craniotomy, if necessary.     

The free-surface shape and temperature distribution produced in liquid metal droplets by heating coil pulses in the TEMPUS electromagnetic levitation facility

We present the results of analytical and numerical calculations of the free-surface shape and temperature distribution produced in liquid metal droplets processed in the TEMPUS electromagnetic levitation facility. The mathematical models were developed to predict the behavior of liquid metal droplets in containerless experiments used to measure thermophysical properties aboard the Space Shuttle Columbia during the IML-2 mission in July 1994. A normal stress balance model was used to numerically calculate the equilibrium free-surface shapes for various samples produced by a number of induction coil voltages. Analytical and numerical calculations were performed to model the heat transfer in the liquid metal droplets during and following the heating coil pulses. The work illustrates the use of mathematical modeling in the design of microgravity experiments and is applicable to industrial processes such as casting and skull melting.     

Latitudinal and insular variation of skull size in crab-eating macaques (primates, Cercopithecidae: Macaca fascicularis)

Macaca fascicularis is broadly distributed in Southeast Asia across 30 degrees of latitude and 35 degrees of longitude (Indochinese Peninsula, Isthmus of Kra, Malay Peninsula, Greater and Lesser Sunda Islands, Philippine Islands, and numerous small, neighboring islands). The range is divisible into 1) a core area comprised of mainland Southeast Asia, Borneo, Sumatra, and Java (large land masses interconnected during the last glacial maximum, 18,000 B.P.); 2) shallow-water fringing islands, which are smaller islands connected to the core area during the last glacial maximum; and 3) deep-water fringing islands, which are peripheral islands not connected to the core area during the last glacial maximum. Skull length was used to study effects of latitude and insularity on patterns of size variation. The data are from 802 adult M. fascicularis specimens from 140 core-area localities, 63 shallow-water islands, and 29 deep-water islands. Sex-specific polynomial regressions of skull length on latitude were used to describe skull length variation in the core area. These regressions served as standards for evaluating variation among samples from shallow-water and deep-water islands. The core area exhibits Bergmannian latitudinal size clines through most of the species range. Thus, skull length decreases from about 8 degrees S (Java) to the equator (Sumatra and Borneo), then increases as far north as about 13 degrees N (Isthmus of Kra). Farther north, to the northernmost Indochinese localities at about 17 degrees N, skull length in M. fascicularis decreases with increasing latitude, contrary to Bergmann's rule. Latitudinal size variation in shallow-water fringing islands generally parallels that in the core area. However, skull length tends to be smaller than in the core area at similar latitudes. Deep-water fringing islands are markedly more variable, with relatively small specimens in the Lesser Sunda Islands and relatively large specimens in the Nicobar Islands. These analyses illustrate how a primate species may vary in response to latitudinal temperature variation and to isolation.     

The posterior cranium and its dysmorphisms

The deformation of the posterior part of the skull (occipito-vertebral region) induced directly, occurs in numerous pathological situations. Its significance is frequently overlooked. Lesions of the cranial content, alterations of the lambdoid suture or other premature synostosis, abnormal constraint related to posture or to muscular activity can modify the posterior curvature of the skull, generally flattening it. The authors propose a classification based on three points: intracranial pathology, bone pathology and extrinsic pathology. Concerning intracranial pathology, alterations of the brain or CSF fluid can induce either insufficient (microencephaly) or excessive (hydrocephalus, Dandy Walker or Arnold Chiari malformations) expansion. Concerning bone pathology, sagittal synostosis (scaphocephaly) induces a bulging and coronal synostosis a flatness of the posterior skull. Bilateral premature lambdoid synostosis (pachycephaly) produces total flatness of the back of the skull. Concerning extrinsic pathology, dysmorphism is often asymmetrical and results from extracranial mechanical application dysfunction such as inborn torticollis, cervical spine pathology (Klippel-Feil syndrome), or prolonged decubitus during the first year of life. The different surgical procedures are described and the authors describe a personal technique for correcting this dysmorphism: the turned biparietal flap transposition. The back of the skull is remodelled (either asymmetrical or bilateral flatness), and patients with no need for a helmet can lie on their backs immediately after the operation.     

Stress-strain state and safe life of the crucible of a skull furnace under thermomechanical loading

Metallurgist - This article examines problems related to the thermomechanical loading of the crucible of a skull furnace during the melting of titanium alloys. Factors that affect the efficiency...     

Shape from stereo: a systematic approach using quadratic surfaces

Postnatal development of the neuro- and viscerocranium with special reference to the maxillodental structures was studied morphometrically by analyzing computer tomograms and radiograms of human and monkey heads of different age groups. The following parameters were used: the prognathic angle, the clivus angle, the palate-incisivus angle, the interincisival angle and the viscerocranial quotient. In the newborn primates including man, all parameters measured were relatively similar; postnatally, however, characteristic differences in the growth pattern between man and monkey were developing. In monkey, a marked prognathic growth of the viscerocranium was found associated with characteristic positional changes of the frontal teeth, whereas the growth of the neurocranium was retarded. Here, unlike the human, a flattening of the skull base was observed. In contrast, the human skull showed no major proportional changes during its postnatal development compared with the original spherical skull form of the newborn.