Neutrophil alterations in pregnancy-associated malaria and induction of neutrophil chemotaxis by Plasmodium falciparum.

Pregnancy-associated malaria (PAM) is a severe form of the disease caused by sequestration of Plasmodium falciparum-infected red blood cells (iRBCs) in the developing placenta. Pathogenesis of PAM is partially based on immunopathology, with frequent monocyte infiltration into the placenta. Neutrophils are abundant blood cells that are essential for immune defence but may also cause inflammatory pathology. Their role in PAM remains unclear. We analysed neutrophil alterations in the context of PAM to better understand their contribution to disease development. Pregnant women exposed to Plasmodium falciparum had decreased numbers of circulating neutrophils. Placental-like BeWo cells stimulated with malaria parasites produced the neutrophil chemoattractant IL-8 and recruited neutrophils in a trans-well assay. Finally, immunostaining of a PAM placenta confirmed neutrophil accumulation in the intervillous space. Our data indicate neutrophils may play a role in placental malaria and should be more closely examined as an etiological agent in the pathophysiology of disease.

Low-grade infection complicating silastic dural substitute 32 years post-operatively.

BACKGROUND: A complication of a silastic dural substitute is described, which appeared after 32 years-by far the longest latency period reported in the literature. METHODS: Case report and literature review. RESULTS: In 1971, a 20-year old woman suffered from an acute subdural haematoma and a temporal cerebral contusion due to a motorbike accident. She underwent an operation with evacuation of these and the dura was mended with a silastic duraplasty. Thirty-two years later she deteriorated with increased memory problems and dysphasia. CT revealed an expanding haemorrhagic mass around the previous duraplasty, which demanded surgery with removal of the silastic dural implant and evacuation of the haemorrhagic mass. Although the haemorrhagic mass enveloped the silastic implant, a contribution of the acrylate flap cannot be ruled out. Bacteriological cultures revealed Acinetobacter spp. in the CSF. Adequate post-operative antibiotic treatment was administered. The patient slowly improved, but the complication represented a major setback in her long-term cognitive and communicative functions. CONCLUSIONS: This case widens the previously reported time-frame of late complications by 60%, from 20 to 32 years, and will hopefully serve to increase the awareness of late infections and haemorrhages induced by silastic dural implants, thereby improving diagnosis and treatment in future cases.

Alternative splicing of the eag potassium channel gene in Drosophila generates a novel signal transduction scaffolding protein.

The Drosophila eag gene has been shown to regulate neuronal excitability, olfaction, associative learning and larval locomotion. Not all of the roles of this gene in these processes can be explained by its function as a voltage-gated potassium channel. In this study, we show that the eag gene is spliced in a PKA- and PKC-regulated manner to produce a protein lacking channel domains. This protein, in the context of activated PKA, can engage cellular signaling pathways that alter cell structure. Nuclear localization is necessary for C-terminal-mediated effects, which also require MAPK. The requirement for PKA/PKC activation in the synthesis and function of this novel protein suggests that it may couple membrane events to nuclear signaling to regulate neuronal function on long time scales.

CaMKII uses GTP as a phosphate donor for both substrate and autophosphorylation.

The vast majority of serine/threonine protein kinases have a strong preference for ATP over GTP as a phosphate donor. CK2 (Casein kinase 2) is an exception to this rule and in this study we investigate whether calcium/calmodulin-dependent protein kinase II (CaMKII) has the same extended nucleotide range. Using the Drosophila enzyme, we have shown that CaMKII uses Mg(2+)GTP with a higher K(m) and V(max) compared to Mg(2+)ATP. Substitution of Mn(2+) for Mg(2+) resulted in a much lower K(m) for GTP, while nearly abolishing the ability of CaMKII to use ATP. These similar results were obtained with rat alphaCaMKII, showing the ability to use GTP to be a general property of CaMKII. The V(max) difference between Mg(2+)ATP and Mg(2+)GTP was found to be due to the fact that ADP is a potent inhibitor of phosphorylation, while GDP has modest effects. There were no differences found between sites autophosphorylated by ATP and GTP, either by partial proteolysis or mass spectrometry. Phosphorylation of fly head extract revealed that similar proteins are substrates for CaMKII whether using Mg(2+)ATP or Mg(2+)GTP. This new information confirms that CaMKII can use both ATP and GTP, and opens new avenues for the study of regulation of this kinase.

Leptomeningeal cyst due to vacuum extraction delivery in a twin infant.

A rare case of a leptomeningeal cyst is reported in a twin male neonate delivered using a vacuum extractor, who presented a huge, non-pulsating, oedematous mass overlying the frontal fontanelle after birth. The mass was initially diagnosed as a cephalo haematoma. Ultrasonography indicated intracranial bleeding and a subsequent CT scan revealed an intraparenchymal bleeding above the left frontal horn, combined with a thin, left-sided, subdural haematoma and subarachnoid haemorrhage in the left Sylvian fissure. Apart from a bulging soft and round formation (2 x 2 x 3 cm) next to the anterior fontanel growing since birth, the neurological development of the infant was normal. MRI examination at the age of 7 months revealed that it consisted of a cystic mass (leptomeningeal cyst) connected to the left frontal horn, stretching right through the brain and also penetrating the dura mater. No signs of the perinatal haematomas were observed at this time. Surgical treatment, with fenestration of the cyst into the frontal horn and a watertight duraplasty with a periosteal flap and thrombin glue covered by small bone chips, was performed at 9 months of age. Due to a residual skull bone defect a second cranioplasty with autologous skull bone was performed three and half years later. During a follow-up period of 12 years the neurological and psychological development of the boy has been indistinguishable to that of his twin brother, indicating the satisfactory outcome of the treatment.

A 62 kDa protein is photoaffinity labelled by [3H]felodipine in vascular smooth muscle, but not in cardiac and skeletal muscle.

Irradiation of a cytosolic fraction from vascular smooth muscle in the presence of [3H]felodipine resulted in the labelling of a protein with an apparent molecular weight of 62 kDa. The labelling was seen on UV-irradiation at 360 nm, but not at 254, 278 or at wavelengths above 410 nm. The photolabelling was enhanced in the absence of oxygen. In cytosolic fractions prepared from porcine liver, cardiac and skeletal muscle no photoaffinity labelling of proteins between 90 and 45 kDa could be demonstrated. The results suggest that felodipine is a photoaffinity ligand and that felodipine binds to a soluble protein present in vascular smooth muscle but not in the other tissues tested.

Binding of a dihydropyridine felodipine-analogue to calmodulin and related calcium-binding proteins.

A dihydropyridine-affinity column was prepared by coupling a physiologically active and vasoselective amino-derivative of felodipine to divinylsulfone-activated Trisacryl GF2000. Calmodulin (CaM) as well as the homologous calcium-binding proteins skeletal and cardiac Troponin C (sTnC and cTnC) and S100b bound to this resin in a calcium-dependent manner. In contrast, other homologous proteins such as parvalbumin and the intestinal calcium-binding protein did not bind. Competition studies showed that CaM had a higher affinity for the felodipine-column than sTnC or cTnC. Through studies with a series of proteolytic fragments of CaM and sTnC, it was found that the felodipine binding site is located in the amino-terminal domain of the protein. These results illustrate the utility of affinity-chromatography for the study of dihydropyridine-binding proteins.

Effects of felodipine on energy turnover in the rat portal vein.

The effects of the vasodilating dihydropyridine, felodipine, on tissue concentrations of high-energy phosphates and on oxygen consumption and lactate production in the smooth muscle of the rat portal vein were investigated. Felodipine (100 nM) caused a gradual decrease in the amplitude of the spontaneous phasic contractions in a calcium-containing medium. The mean active force was reduced by about 80% within 15 min. The inhibition of force was associated with reductions in both oxygen consumption and lactate production. No effects of felodipine could be observed in a calcium-free solution. The metabolic rates and force during felodipine inhibition approached those recorded in the calcium-free media. Felodipine (30 nM) did not alter the tissue levels of ATP, ADP, AMP and phosphocreatine. Relaxation by felodipine is thus associated with a decreased energy demand for contraction and, possibly, ionic translocation. The reduced ATP hydrolysis is compensated for by the regeneration of metabolic ATP, thus keeping the cellular levels of high-energy phosphates constant.

Determination of the kinetic constants of tissue factor/factor VII/factor VIIA and antithrombin/heparin using surface plasmon resonance.

Association of factor VIIa (FVIIa) with tissue factor (TF) is generally believed to be a critical step in the initiation of blood coagulation. In this study the rate constants for the complex formation and dissociation between FVII/FVIIa and TF were studied in real time using surface plasmon resonance, the BIAcore technique. Employing this technique ka and kd were determined and yielded a KD of 1 nM for FVII and 0.5 nM for FVII, respectively. The association and dissociation between antithrombin (AT) and the FVIIa/TF complex was also studied. In the presence of heparin, AT was bound to the FVIIa/TF complex in a dose-dependent manner with ka of 2 x 10(3) M-1 s-1. The binding of AT to FVIIa/TF increased the dissociation of FVIIa from TF about 20-fold.

Endothelial prostacyclin production, synergistic effect between adrenergic stimulating and blocking drugs.

Endothelial cells (EC) produce prostacyclin (PGI2) in high quantities which at the luminal surface decreases platelet aggregation and adhesion and basal to the cell relaxes smooth muscle cells (SMC). Connections have been reported between prostacyclin production, hypertension and the degree of adrenergic activation. The present study tested the hypothesis that prostacyclin production by EC could be regulated by adrenergic mechanisms. EC were isolated from human umbilical cord veins. Washed cells were seeded and grown to confluency on tissue culture dishes. The test drugs were simultaneously added to parallel dishes. Samples were collected from the conditioned medium and analyzed for 6-keto-PGF1a with RIA technique. Endothelial cells pretreated with the betaadrenoceptor blocking drugs metoprolol or propranolol synergistically increased basal prostacyclin production when exposed to betaadrenergic stimulation. However, using isomers with high or low betaadrenoblocking effect, this synergism was demonstrated not to be associated to the betaadrenoceptor blocking effect of the drugs per se. These findings may have implications on the arterial hypertensive state characterized by high sympathetic tonus and low PGI2 production. The data may offer an explanation why hypertensive individuals react with increased PGI2 production, upon betaadrenoceptor blocking therapy.

Conformational differences between latent and active plasminogen activator inhibitor, PAI-1: a spectroscopic study.

The protein conformation of latent and active PAI-1 has been studied with circular dichroism, absorbance and fluorescence spectroscopy. The far ultraviolet circular dichroism spectrum of latent PAI-1 displays a more negative band at 220 nm than active PAI-1, crossing the baseline at a lower wavelength. Active PAI-1 shows an absorption maximum at lower wavelength (269 nm) than present in latent PAI-1 (278 nm). In consistency, slow denaturation of active PAI-1 by incubation for two hours at 37 degrees C induces a shift in the absorption maximum from 268 nm to 274 nm. The fluorescence emission maximum of latent PAI-1 is at lower wavelength (335 nm) than that of active PAI-1 (340 nm). These spectroscopic differences are interpreted as reflecting a more tight conformation, with the tryptophan residues in a more apolar environment, in latent PAI-1 compared to active PAI-1.

Reversibility of severe sagittal sinus thrombosis with open surgical thrombectomy combined with local infusion of tissue plasminogen activator: technical case report.

OBJECTIVE: To explore the controversial issue of anticoagulant therapy and indications for surgery in association with severe sinus thrombosis. METHODS: During the last 4 years, we have treated three patients with severe sinus thrombosis of the dural sinuses. All three patients received systemic anticoagulant therapy and, after experiencing neurological deterioration, underwent open thrombectomy and local thrombolysis. After the operation, aggressive intensive care was given and included cerebral perfusion monitoring, barbiturate administration, hyperventilation, and osmotherapy. The treatment was guided by repeated neuroradiological investigations. RESULTS: All three patients returned to their normal lives. CONCLUSION: Intracranial sinus thrombosis, even in the worst neurological state, should be treated aggressively. A cornerstone in treatment is systemic anticoagulant therapy and repeated neuroradiological studies. When, despite adequate anticoagulant therapy and intensive care, neurological deterioration occurs, a combination of open thrombectomy and local thrombolytic therapy should be considered.

Late complications of Silastic duraplasty: low-virulence infections. Case report.

The authors describe three patients with expanding hemorrhagic mass lesions who presented 13 to 18 years after undergoing Silastic duraplasty. In all patients, results of bacteriological cultures of the masses obtained intraoperatively were positive, revealing low-virulence bacteria. Two of the patients were treated with antibiotic drugs and made a good recovery. The third did not receive antibiotic medications initially and later developed an epidural empyema that necessitated reoperation, but subsequently made a complete recovery. Vascularized neomembranes are generally agreed to be causes of the expanding masses, but the possibility that patients could be harboring chronic infections must be considered. Thus, on removal of duraplasty materials a complete bacteriological culture should be obtained, and if it is positive the proper antibiotic therapy should be administered. Furthermore, the creation of a registry of patients who have received implants is advocated to facilitate tracking of implanted material in case of complications.

Mobile computerized tomography scanning in the neurosurgery intensive care unit: increase in patient safety and reduction of staff workload.

OBJECT: Transportation of unstable neurosurgical patients involves risks that may lead to further deterioration and secondary brain injury from perturbations in physiological parameters. Mobile computerized tomography (CT) head scanning in the neurosurgery intensive care (NICU) is a new technique that minimizes the need to transport unstable patients. The authors have been using this device since June 1997 and have developed their own method of scanning such patients. METHODS: The scanning procedure and radiation safety measures are described. The complications that occurred in 89 patients during transportation and conventional head CT scanning at the Department of Radiology were studied prospectively. These complications were compared with the ones that occurred during mobile CT scanning in 50 patients in the NICU. The duration of the procedures was recorded, and an estimation of the staff workload was made. Two patient groups, defined as high- and medium-risk cases, were studied. Medical and/or technical complications occurred during conventional CT scanning in 25% and 20% of the patients in the high- and medium-risk groups, respectively. During mobile CT scanning complications occurred in 4.3% of the high-risk group and 0% of the medium-risk group. Mobile CT scanning also took significantly less time, and the estimated personnel cost was reduced. CONCLUSIONS: Mobile CT scanning in the NICU is safe. It minimizes the risk of physiological deterioration and technical mishaps linked to intrahospital transport, which may aggravate secondary brain injury. The time that patients have to remain outside the controlled environment of the NICU is minimized, and the staff's workload is decreased.

Hodgkin's lymphoma of the uterus presenting as refractory pelvic inflammatory disease. A case report.

Lymphoma rarely presents with initial involvement of the uterine corpus, though disseminated disease may well involve the pelvic organs secondarily. We treated a patient for Hodgkin's lymphoma presenting as pelvic serositis found at hysterectomy for refractory pelvic pain. Nodules consistent with Hodgkin's lymphoma were found within the uterine serosa and muscularis as well as throughout the uterine and tubal lymphatics, but no visible or palpable adenopathy was noted in the pelvis or abdomen or peripherally. Following surgery the patient developed signs and symptoms of widespread lymphoma, which developed fulminantly but responded well initially to standard chemotherapy. This is the first reported case of systemic Hodgkin's lymphoma presenting de novo in the uterine corpus and associated with clinical symptoms referable to the female reproductive tract.

Correlation between cervical cytology and biopsy in an air force colposcopy clinic.

We examined 258 patients in the colposcopy clinic at David Grant USAF Medical Center from January 1980 to December 1982. Two hundred eleven records (82%) were comprehensive enough to be reviewed. Forty-six percent (97 of 211) of the original cervical (Papanicolaou) smears showed only atypia. Forty percent (39 of 97) of them subsequently showed dysplasia on colposcopically directed cervical biopsy. When cervical smears were repeated at the initial colposcopy clinic visit, 36% (75 of 211) were negative. There were no cases of invasive cervical cancer.