Tripartite hemolysin BL from Bacillus cereus. Hemolytic analysis of component interactions and a model for its characteristic paradoxical zone phenomenon

This study describes the use of the microdialysis technique to elucidate specific properties of the circadian pacemaking system in the hypothalamus, by measurement of melatonin production in the pineal gland. Melatonin has appeared to be a reliable marker of the pacemaker activity, which is influenced by the light/dark cycle. A phase shift in the light/dark cycle was applied to perturb the rhythm generating system. An 8-h phase advance resulted in the disappearance of melatonin production over two days, with basal levels comparable to normal daytime levels. In the subsequent return of rhythmic melatonin production, new clock characteristics could be revealed, due to the high time-resolution measurements of microdialysis. While half of the animals still did not show any rhythmicity, the other half of the animals regained rhythmicity with entrained onset of melatonin production, while the offset was variable and not stably entrained to lights on. Ten days after the shift, the system had completely recovered and all animals regained normal rhythmicity, in phase with the new light/dark cycle. The results are interpreted in terms of the two-oscillator model, with one oscillator reacting with a phase advance and the other with a phase delay to adapt to the phase shift.     

SPECT, CT, and MRI in head injury: acute abnormalities followed up at six months

We report a case of cervicofacial necrotizing fasciitis that developed after blepharoplasty, an occurrence that, to our knowledge, has not previously been reported in the medical literature. A patient who presented to our institution 3 days after undergoing blepharoplasty of the upper eyelid was diagnosed as having fulminant fasciitis involving extensive areas of the face, scalp, and neck. We review the case in detail and discuss clinical and radiological clues to diagnosis, surgical and medical management, wound care, and subsequent scar contracture. This case emphasizes the need for individualized, appropriate postoperative care and for an awareness of this rare, potentially fatal complication. Early recognition and aggressive treatment of cervicofacial fasciitis can arrest its rapid progression and prevent devastating sequelae.     

Conserved features of TBE1 transposons in ciliated protozoa

BACKGROUND: Accessory function (AF) is one way antigen presenting cells generate sufficient secondary signals for optimal T-cell proliferation and IL-2 production. In general, alveolar macrophages (AM) are inferior accessory cells in comparison to monocytes whereas in sarcoidosis AF of AM is increased. METHODS: We compared the accessory index (AI) of AM and peripheral blood monocytes (PBM) of 41 patients with inactive sarcoidosis (SAR I, n = 12); active sarcoidosis with new or progressing symptoms (SAR II, n = 19), active sarcoidosis with spontaneous remission (SAR III, n = 10), tuberculosis (TB, n = 12), hypersensitivity pneumonitis (HP, n = 12), Wegener's disease (WD, n = 2), undefined alveolitis (UA, n = 8) and chronic obstructive pulmonary disease (COPD, n = 6) by employing the histoincompatibility-insensitive Jurkat cells as indicator cells. RESULTS: Compared with the controls (1.08 +/- 0.3) AMs of all groups but SAR I (AI: 0.96 +/- 0.42) exhibited significantly increased AIs (SAR II: 3.6 +/- 3.9; SAR III: 3.2 +/- 2.4; TB: 2.8 +/- 2.2; HP: 3 +/- 2; UA: 2.7 +/- 2.3; COPD: 3.1 +/- 2.2; p < 0.05 for all comparisons). Only in HP, AI of PBM was significantly increased compared with controls (3 +/- 1.5, 1.3 +/- 0.5, respectively; p < 0.001). Alveolar macrophages from patients with arcoidosis, TB, and HB express the costimulatory molecule CD80 on their surface and anti-CD80 antibodies inhibited the IL-2 release of Jurkat cells in this system to 59 +/- 27%. CONCLUSIONS: Our data demonstrate that AM from patients with various diseases have the capability to act as competent accessory cells and that the reported accessory function of these cells is at least in part mediated by the expression of CD80.     

Prenatal diagnosis of an extensive fetal lymphangioma using ultrasonography, magnetic resonance imaging and cytology

An unusual case of fetal lymphangioma diagnosed before delivery is reported in a second trimester pregnant woman. The lymphangioma was suspected at 28 weeks on the basis of the ultrasound appearances and progression of the lesions with advancing gestation. MRI was used to evaluate the extent and the tissue characteristics of the lesions. Cytology of the fluid aspirated from the cystic lesions showed abundant lymphocytes and macrophages, confirming the diagnosis of a lymphangioma. The parents opted for a pregnancy termination because of the rapid growth of the lesions and the poor prognosis. It is suggested that the combination of these tests could enable the early diagnosis of these tumours at a stage when the lesion is relatively limited and accessible to therapy in utero.     

The influence of nicotine pretreatment on mesoaccumbens dopamine overflow and locomotor responses to D-amphetamine

In this retrospective cephalometric study of mandibular rotational change, we studied 60 cases. All patients were treated with full fixed appliances and exhibited an opening rotation of at least 1.5 degrees during treatment, as measured on the basis of the angle of the Y-axis to the sella-nasion line (SN). Our objective was to determine whether this opening rotation was sustained during retention. Paired t tests were used to test the hypothesis that the treatment change or opening rotation was stable and that these patients did not return to their original mandible-to-cranium relationship in the posttreatment period. Stepwise regression analysis was used to determine which (if any) changes in the independent variables during treatment could predict the subsequent behavior of the angle of the mandibular plane to the SN and the angle of the Y-axis to the SN during retention. During treatment, the mean increase in the angle of the Y-axis to the SN was 2.43 degrees. After an average posttreatment period of 54 months, this angle was reduced on average by only 0.73 degrees. Stepwise linear-regression analysis indicated that none of the treatment changes seen in the independent variables strongly predicted the ensuing closing rotation seen during retention. The correlation coefficient between the Y-axis angle and the mandibular-plane angle during treatment was 0.67. Mandibular opening rotations as a consequence of orthodontic treatment do not invariably return to the pretreatment value, and their negative effects--although sometimes small--cannot be discounted. Because the preponderant evidence of a closing rotation occurs in the terminal pubertal growth stages, the net effect may be even more significant.     

In situ localization and chromosomal mapping of the AG1 (Dmp1) gene

Dentinogenesis is being used as a model for understanding the biomineralization process. The odontoblasts synthesize a structural matrix comprised of Type I collagen fibrils which define the basic architecture of the tissue. The odontoblasts also synthesize and deliver a number of dentin-specific acidic macromolecules into the extracellular compartment. These acidic macromolecules may be involved in regulating the ordered deposition of hydroxyapatite crystals within the matrix. AG1 is the first tooth-specific acidic macromolecule to have been cloned and sequenced. To identify which cells of the rat incisor pulp/odontoblast complex were responsible for synthesis of AG1, in situ hybridization was used. Digoxigenin labeled sense and anti-sense AG1 riboprobes were prepared. The AG1 mRNA was found to be expressed in the mature secretory odontoblasts. Neither pulp cells nor pre-odontoblasts showed any staining with the anti-sense probes. Chromosomal localization studies placed the AG1 gene on mouse chromosome 5q21, in tight linkage with Fgf5. AG1 has been renamed Dmp1 (dentin matrix protein 1) in accordance with present chromosomal nomenclature. Mouse 5q21 corresponds to the 4q21 locus in humans. This is the locus for the human tooth mineralization disorder dentinogenesis imperfecta Type II (DI-II). These data suggest that the Dmp1 gene is involved in mineralization and is a candidate gene for DI-II.     

Height, occupation and back pain in a national prospective study

Back pain is an important public health problem but there is a paucity of knowledge about risk factors and causal mechanisms. Previous studies have shown that tall men are more at risk of back pain, although observations in women have been less consistent. This paper presents findings from a national longitudinal study of 3262 men and women aged 43 yr. Standing height and sitting height were related to 18-month reported prevalence of 'sciatica, lumbago or severe backache' in both men and women. The paper investigates explanations for these findings using previously collected data on childhood growth and detailed lifetime occupational histories. Neither greater susceptibility of tall men to heavy lifting, nor the timing of growth, were able to account for these relationships. To assess further the association between height and back pain, information is needed on the relationship between stature and characteristics of spinal structure.     

Delayed onset of malignant hyperthermia induced by isoflurane and desflurane compared with halothane in susceptible swine

BACKGROUND: Desflurane (difluoromethyl 1-fluoro 2,2,2-trifluoroethyl ether) is a new inhalational anesthetic currently under investigation for use in humans. Recently, the authors showed that desflurane is a trigger of malignant hyperthermia (MH) in susceptible swine. To date, there has been no in vivo comparison of the relative ability of inhalational anesthetics to trigger MH. The effects of desflurane, isoflurane, and halothane on six MH-susceptible purebred and six MH-susceptible mixed-bred Pietrain swine were examined. METHODS: The animals were exposed to 1 MAC and 2 MAC (if MH was not triggered after 1 MAC hour) doses of each of the three volatile anesthetics in random sequence at 7-10-day intervals and changes in end-tidal CO2, arterial blood gases, serum lactate, core and muscle temperature, blood pressure, and heart rate were measured. RESULTS: There was a statistical difference between anesthetics in the time required to trigger MH; halothane exposure resulted in the fastest onset of an MH episode (20 +/- 5 min), compared with isoflurane (48 +/- 24 min) and desflurane (65 +/- 28 min), both of which required significantly longer exposures. There was no statistical difference between the MH purebred and mixed-bred swine in the time required to trigger MH (defined as a PaCO2 of 70 mmHg) with a given agent, and time to triggering was also independent of the order of exposure to the three anesthetics. Malignant hyperthermia susceptibility was confirmed in ten surviving animals, by both in vivo succinylcholine challenge and in vitro contracture testing. CONCLUSIONS: Although all three volatile anesthetics triggered MH, exposure to halothane resulted in significantly shorter times to MH triggering when compared with desflurane and isoflurane.     

Vascular rejection post heart transplantation is associated with positive flow cytometric cross-matching

28 isolates of canine parvovirus type-2 (CPV-2) were obtained from dogs with hemorrhagic gastroenteritis in Italy. The antigenic structure of CPV-2 isolates was characterized, using four discriminating monoclonal antibodies. In addition, four vaccinal strains were examined. Similar to reports from Australia and the United Kingdom, a much higher prevalence of CPV-2a (25/28 isolates) was observed than the other variant type, CPV-2b (3/28 isolates). DNA fragments (2.2 kbp) of representative strains of CPV-2, CPV-2a and CPV-2b were amplified by the polymerase chain reaction (PCR) and the products were digested by the restriction enzymes (RE) RsaI, HpaII, HindIII and PvuII. The RvaI enzyme allows the differentiation of CPV-2 from CPV-2a and CPV-2b.