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.

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 new scaled microgauge for use in neurosurgery

A new scaled microgauge is described for measuring anatomical structures during microsurgery. The instrument has a tip marked in millimetres, which can be positioned in any desired angle enabling measurement in confined areas.

Behçet's disease, associated with subarachnoidal heamorrhage due to intracranial aneurysm

Behçet's disease is an unusual medical condition in central Europe and North America, however more common in Turkey and Japan. It was originally described in Turkey, characterized by recurrent oral ulcers, genital ulcers and also uveitis. A variety of vascular lesions such as venous occlusions, arterial aneurysms and varices account for the high rate of morbidity and mortality with this disease. Arterial aneurysms most commonly occur in the abdominal aorta, femoral arteries and in the pulmonary arteries. To our knowledge there have been seventeen documented reports of patient's with Behçet's disease combined with aneurysms of cerebral arteries. We describe a patient with Behçet's disease and subarachnoid haemorrhage due to a ruptured cerebral aneurysm.

Improved brain protection at decompressive craniectomy--a new method using Palacos R-40 (methylmethacrylate)

A new method is described for protecting the brain after decompressive craniectomy in which a temporary methylmethacrylate flap is formed, somewhat larger than the original bone flap, thus gaining "extra" volume for the oedematous brain in which to expand. The present procedure was developed as a part of ordinary clinical practice particularly in response to demands from the NICU staff and our colleagues at other clinics who were responsible for the care of the patient in the post NICU period. They made us keenly aware that these patients frequently lack optimal co-ordination and balance and therefore run an increased risk of trauma to the unprotected brain when falling. This prompted us to develop a method for brain protection after decompressive craniectomy aiding in the care and rehabilitation until the final installation of the patient's own bone flap can be performed.

Postoperative pseudoaneurysm of the superficial temporal artery (S.T.A.) treated with Thrombostat (thrombin glue) injection

BACKGROUND

Pseudo-aneurysm is a rare complication of craniotomy. Blunt injury to the temporal artery region is the usual cause, but still a rare complication.

CLINICAL PRESENTATION

A patient with subarachnoid hemorrhage was successfully treated by aneurysm clipping. The patient developed hydrocephalus, and was admitted for a shunt operation seventeen days later. The craniotomy had healed normally, but a palpable temporal lump was present in the skin incision.

INTERVENTION

The pulsating mass proved to be a postoperative aneurysm of the superficial temporal artery (S.T.A.) and was successfully occluded with 500 units Thrombostat (thrombin glue) which was injected into the aneurysm sac using a 22-gauge needle guided by ultrasound. The permanency of the obliteration was verified by ultrasound examination.

Exploring sex differences in case fatality in acute myocardial infarction or coronary death events in the northern Sweden MONICA Project

OBJECTIVES

To investigate sex differences in reaching diagnosis, medical management and case fatality (CF) in acute myocardial infarction (AMI) in the population aged 35-64 years in northern Sweden.

METHODS

Within the framework of the World Health Organization Multinational Monitoring of Trends and Determinants in Cardiovascular Diseases (MONICA) Project, definite AMI was monitored in people aged 35-64 years from 1989 through 1995 (target population 510 000 in 1991).

SETTING

In a population based coronary register, all coronary events were recorded in nine hospitals in 1989-95.

RESULTS

The number of events included in the definite coronary myocardial infarction register was 2483 men and 669 women. On admission, a higher proportion of men with definite AMI had chest pain or ECG changes typical for AMI (P < 0.0001). Disagreement between clinical diagnosis and classification by MONICA criteria occurred more often in women (P=0.008). A significantly higher proportion of men was admitted in the coronary care unit and they were significantly more often treated with thrombolytics, nitroglycerine, beta-blockers, or antiplatelet agents. Women received significantly more diuretics, inotropics or calcium antagonists. Diabetes, conferring a worse prognosis, was more common in women (20 vs. 15%; P=0.003). Prehospital CF was significantly higher in men (24.1 vs. 18.3%; P=0.005), but in patients treated in hospital, the CF was significantly lower in men (12.7 vs. 21.2%; P < 0.001). Total CF was equal in men and women.

CONCLUSIONS

Several factors contributing to the excess in-hospital CF in women were identified, including greater problems in diagnosis of AMI in women which may be one of the reasons for less intensive treatment in women. Differences in co-morbidity, most notably diabetes and medical treatment between men and women with acute AMI may also have played a part.

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.

Mite fauna in the home and sensitivity to house-dust and storage mites

In search of potential new indoor allergen sources, all mites in dust from homes of 55 asthmatic children living in three climatic regions in Sweden were counted and identified by light microscope. Antibodies of the IgE class against three house-dust mites and three storage mites were measured in corresponding serum samples. Mites were found in all but two homes from the northernmost area, where levels also were lower than in the other regions. The highest mite densities were most often found in bedrooms (50%) and living rooms (40%). Mite density was increased in homes with high humidity and was higher in bungalows than in flats. House-dust mites predominated in the south and storage mites in the east central area, particularly in kitchens and bathrooms. Mite-density and IgE-antibody levels against house-dust mites were significantly associated. The same association applied to storage mites. Other species numbered around 100 mites/g dust in some homes. Microscopy helps to identify potentially important mites. Analysing home dust only for house-dust mites will underestimate mite exposure. Storage mites may be as relevant to sensitivity as house-dust mites. As other species occasionally were found in high numbers, their relevance should also be assessed.

A new bone dust packer for use in neurosurgery

A new tool for the packing of bone dust has been developed. The instrument compresses a mixture of bone dust and saline into suitable cylindrical plugs, fitting neatly into craniotomy burrholes. The skullbone at the craniotomy area will heal neatly also assuring the best healing possibilities for the overlying skin. The cosmetic results are excellent as no skin dents or cavities will be formed over the burrholes.

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.

The dual-tube microsurgical suction instrument

A dual-tube suction instrument intended for both macro- and microsurgery has been developed. A detachable air-tight inner tube is fitted into a conventional suction instrument; extending the ordinary sucking tube. The inner tube can easily be fitted, as well as removed from the other tube; a particular advantage in case the inner tube becomes obstructed. On removal of the inner tube the outer tube becomes cleaned and is at once, ready for re-use. Since the suction instrument does not have to be removed from the suction hose, valuable time is saved, enabling permanent sucking capacity.

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.

Environmental assessment of Dermatophagoides mite-allergen levels in Sweden should include Der m 1

The major allergen of Dermatophagoides microceras, Der m 1, as well as the allergens of D. pteronyssinus and D. farinae, Der p 1 and Der f 1, were analyzed in the homes of 111 asthmatic children in three climatic regions in Sweden. The numbers and species of mites were determined by microscopy, and circulating IgE antibodies against mites were measured. Der f 1 was the predominant house-dust-mite (HDM) allergen, Der p 1 the least often found, and Der m 1 represented 31% of the allergen load. However, in the Linköping area, Der m 1 was the major HDM allergen (58%). Mite counts and allergen levels correlated well. Current exposure to HDM allergens at home was associated with the serum IgE antibody response to HDM in the children with no threshold level. Of the children with IgE antibodies against HDM, 67% reacted to all three mites. Mite sensitization rates were marginally increased (7%) by the addition of IgE analysis of D. microceras to the routine analysis of IgE antibodies against D. pteronyssinus and D. farinae. Thus, Der m 1 may be an important HDM allergen and should be considered when HDM exposure data are assessed in areas with a climate like that of Sweden.

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.

Intracranial subdural haematoma--a rare complication following spinal anaesthesia

We present a rare case with postspinal headache resulting in an intracranial subdural haematoma. After 5 days of persistant headache the condition was recognized and diagnosed on a computerized tomography-scan (CT) of the skull. The patient was operated with evacuation of the haematoma 2 weeks after the spinal anaesthesia and recovered completely.

Different fibrinolytic potentials between human umbilical vein endothelial cells and human adult vein endothelial cells

Endothelial cells play a central role in fibrinolysis due to their production of both tissue plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1). The purpose of this study was to test the hypothesis that the production of t-PA and PAI-1 from human umbilical vein endothelial cells (HUVEC) and from human adult vein endothelial cells (HAVEC) adopt the same pathways for the regulation of fibrinolysis, and that differences in PAI-1 and t-PA production are only quantitative. HUVEC and HAVEC cultures were exposed to phorbol ester (PMA), endotoxin (LPS) or thrombin, singly or in combination with forskolin or H7. The conditioned medium was collected after 16 h and analyzed for t-PA and PAI-1 antigens. The basal production of both t-PA and PAI-1 was significantly higher from HUVEC than from HAVEC. Exposure to PMA, thrombin or forskolin gave a similar response from the two cell types. In contrast, the results from HUVEC and HAVEC differed significantly, not only in magnitude but also in direction, when the cells were exposed to forskolin coincubated with PMA, LPS or thrombin, and in magnitude alone when exposed to LPS only. The results indicate that there are not only quantitative but also qualitative differences in the production of t-PA and PAI-1 from HUVEC and HAVEC. These differences must be taken into account when data from cells of different origin are compared.

Complex intracellular signal transduction regulates tissue plasminogen activator (t-PA) and plasminogen activator inhibitor type-1 (PAI-1) synthesis in cultured human umbilical vein endothelium

Endothelial cells are central in fibrinolysis because of their high production of both activators (t-PA, uPA) and inhibitors (PAI-1). The t-PA and PAI-1 synthesis could be regulated by signals transduction at several cellular levels. The purpose of this in vitro study, on cultured endothelial cells, was to explore the receptor/second messenger regulation of the t-PA and PAI-1 synthesis. Quiescent confluent human umbilical vein endothelial cells, cultured in passage 1, were exposed to different test substances. Samples from the conditioned medium were collected after 16 and 24 h and analysed for t-PA and PAI-1 antigen. All data presented were related to the data from control dishes (= 100%), in the same experiment. The results from the present study (mean +/- 95% confidence interval) demonstrated the following. (1) Forskolin, with a documented direct cAMP-inducing effect, decreased the basal PAI-1 production to 61 +/- 15%, and Na-nitroprusside, with a documented cGMP-inducing effect, increased the basal PAI-1 production to 141 +/- 38% without affecting the basal t-PA production. The surface receptor agonists isoprenalin or ephedrine, which indirectly affect adenylate cyclase, had no effect on t-PA or PAI-1 production. (2) Phorbolester (PMA), which directly activates proteinkinase C (PKC), increased the basal t-PA and PAI-1 production to 350 +/- 71%, and 163 +/- 35% respectively. (3) Thrombin, but not endothelin-1 (ET-1), increased the basal t-PA and PAI-1 production to 195 +/- 34% and 136 +/- 18%, respectively, indicating an PKC-mediated thrombin effect.(ABSTRACT TRUNCATED AT 250 WORDS)

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.

Separation of active and inactive forms of recombinant human plasminogen activator inhibitor type 1 (PAI-1) expressed in Chinese hamster ovary cells: comparison with native human PAI-1

Human plasminogen activator inhibitor type 1, PAI-1, was expressed in Chinese hamster ovary cells. A production level of 10-15 mg latent PAI-1 per liter of media was achieved after methotrexate amplification. Latent recombinant PAI-1 was purified by two chromatographic steps, cation exchange chromatography on CM-Sepharose and affinity chromatography on heparin-Sepharose. The obtained latent PAI-1 was approximately 90-95% pure showing one homogenous peak upon size-exclusion chromatography. However, four different isoforms due to different degrees of sialylation could be seen upon isoelectric focusing. Purified latent PAI-1 was activated by incubation in 6 M guanidine-HCl. By this method, 40-60% of PAI-1 was converted to an active form after removing the denaturant. The active fraction of PAI-1 was separated from inactive material by size exclusion chromatography on Superdex 200. Active PAI-1 migrated as expected for a 43-kDa large protein, while inactive PAI-1 migrated as larger protein complexes, suggesting that the remaining inactive PAI-1 was in the form of aggregates. This method for the separation of active and inactive PAI-1 could also be used for activated native PAI-1 prepared from human endothelial cells. Active recombinant PAI-1 was remarkably stable at pH 5.5, both when stored on ice and when stored at room temperature.

Telescopic suction tube for microsurgery

An adjustable telescopic suction tube has been developed for microsurgery. Owing to this innovation, the surgeon can easily set the suction tube to a suitable length by gently pulling the end of the telescopic tube out or in.

New microsurgical suction tubes

A set of new suitable microsurgical suction tubes has been designed especially suitable for fragile and delicate tissues such as the nervous and vascular tissues in the brain and spinal cord. The set provides two different shafts and five different tubes for superficial of deep micro- as well as macro-operations. These new suction tubes have two major advantages compared to traditional suction tubes. Firstly: the perforated smooth suction-tip allows continuous suction without damage to the tissue and secondly: the tubes are quickly and easily exchanged from the suction shaft when necessary.

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.

Reconstruction of craniotomy burr-holes with autologous bone blugs made by a new hole-saw

A new craniotomy tool is described. The original De Martell drill was redesigned into a hole-saw for simultaneous production of burr-holes and appropriate autologous bone plugs. The plugs can easily be reinserted and locked in place using bone dust and Tiseel glue permitting appropriate healing and satisfactory cosmetic appearance.

Effect of disulfiram on the platelet function and fibrinolysis in healthy volunteers

Disulfiram was studied for platelet and fibrinolytic activity in 12 healthy volunteers of both sexes (age 23-75 years). Placebo was given for 7 days, followed by disulfiram, 800 mg for 2 days and 400 mg for an additional 12 days. Finally, there was another placebo period of 14 days. With the exception of an initial platelet activation on day 2, no significant effects were found on the platelet variables studied: platelet aggregation with collagen, ADP and adrenaline, beta-thromboglobulin and platelet factor 4. Treatment for 14 days with disulfiram resulted in a decreased euglobulin clot lysis time: from 421 +/- 82 to 246 +/- 41 min (p less than 0.01). After an initial increase, plasminogen activator inhibitor activity was slightly decreased on disulfiram, from 8.4 +/- 1.6 on placebo to 6.0 +/- 1.2 U/ml (p less than 0.05) after 14 days of treatment. Plasminogen, fibrinogen and alpha 2-antiplasmin were unchanged. It is concluded that disulfiram can increase fibrinolytic activity in healthy subjects.

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 the beta-blockers timolol and H 216/44 to ocular melanin

The eyes from pigmented rabbits were instilled with the beta-adrenoceptor antagonists H 216/44 or timolol. After a single instillation (1.9 mumol), the iris and ciliary body contained H 216/44, which decreased with a half-life of approx. 43 days. Daily instillation caused a gradual increase in the content of H 216/44 and timolol in the iris and ciliary body, the steady-state concentration of timolol being 10 times higher than that of H 216/44. The concentrations of H 216/44 were seven times higher in the iris and ciliary body of pigmented rabbits than in albino animals. H 216/44 was reversibly bound to the melanosomes from the iris and ciliary body and not metabolized in this tissue. In vitro binding of timolol and H 216/44 to bovine melanosomes showed comparable multi-site binding curves. The binding of chlorpromazine was substantially higher. The beta-blockers could be more readily released from the melanosomes with aqueous solutions of salt and ethanol than with distilled water. It is concluded that both H 216/44 and timolol bind reversibly to ocular melanin. The differences in binding characteristics in vitro may only partly explain the differences in the in vivo binding to ocular melanin in the rabbit eye.

Fibrinopeptide A and fibrinogen fragment B beta 15-42 and their relation to the operative trauma and post-operative thromboembolism in neurosurgical patients

In an earlier study on post-operative thromboembolism in neurosurgery the incidence of deep vein thromboses (DVT) diagnosed by the fibrinogen uptake test and phlebography was reduced to the same extent by two different prophylactic methods (low dose heparin or calf muscle stimulation + dextran). However, patients with lower limb paresis due to a brain lesion experienced relatively often a less successful prophylaxis compared to patients with spinal lesions. There are few reports on successful clinical methods for haematological screening of post-operative DVT. The aim of this study was to examine possible haematological indicators for post-operative thromboembolism and secondarily to elucidate whether there exist some special coagulatory or fibrinolytic characteristics in patients who had been operated upon for brain lesions. We have studied two specific coagulatory factors (FPA reflecting thrombin generation and B beta 15-42 reflecting plasmin activity) in connection with neurosurgical operations. Patients in the above-mentioned study on post-operative DVT operated upon for malignant cerebral tumours or intracranial vascular disease exhibited post-operatively higher values for FPA compared to other neurosurgical diagnoses. B beta 15-42 was higher in the malignant tumour group and almost significantly higher in the intracranial vascular group (p less than 0.065). These differences could not be ascribed to the occurrence of DVT. Another 15 patients divided into a minor and a major lesion group were investigated with determination of both parameters pre- and post-operatively. Concerning FPA an increase was noticed post-operatively compared to pre-operatively in the major lesion group.(ABSTRACT TRUNCATED AT 250 WORDS)

Photoaffinity labeling of felodipine-binding proteins in vascular smooth muscle

[3H]-Felodipine and high-intensity ultraviolet irradiation were used in the photoaffinity labeling of soluble proteins prepared from porcine mesenteric vascular smooth muscle. Irradiation of the soluble proteins in the presence of [3H]-felodipine resulted in the labeling of a protein with an apparent molecular weight of 62 kDa when analyzed by SDS-polyacrylamide gel electrophoresis. Labeling of the protein did not occur without ultraviolet irradiation. An [3H]-azido analog of felodipine was found to show less specificity than felodipine in its protein labeling when irradiated, since proteins with apparent molecular weights of 44, 29, and 14, as well as 62 kDa, were labeled. The photoaffinity labeling of the proteins were inhibited by excess of unlabeled felodipine.

Post-operative thromboembolism in neurosurgery. A study on the prophylactic effect of calf muscle stimulation plus dextran compared to low-dose heparin

This study compares the safety and effectiveness of two methods for the prophylaxis of post-operative thromboembolism in neurosurgical patients: A: low-dose heparin (5,000 IU X 2 s.c.) started preoperatively and continued daily for one week post-operatively, and B: per-operative electrical calf muscle stimulation with groups of impulses plus post-operative dextran infusions every other day for one week. Neurosurgical patients aged 40 years or more with normal laboratory coagulation values and operated under general anaesthesia were included. The 125:I-fibrinogen uptake test (FUT) was used for screening and phlebography for verification of deep venous thrombosis (DVT). 122 patients entered the study and 104 completed the prophylactic protocol, 58 in group A and 46 in group B. The two groups were comparable according to pre-operative data and distribution of diagnoses. 89 patients completed screening for post-operative DVT. We found an overall incidence of 5/49 (10 percent) DVT in group A and 5/40 (13 percent) in group B, compared to a frequency of 32-50 percent for controls without prophylaxis reported in the literature, In spite of prophylaxis our patients with intracranial neoplasms and intracranial vascular disease showed a relatively higher incidence of DVT, 4/23 (17 percent) and 4/14 (29 percent) respectively, compared to patients with spinal diagnoses 2/25 (8 percent). In combination with cranial diagnoses paretic lower limbs meant an apparent risk factor, 4/7 (57 percent). However, paretic limbs appearing in cases with spinal disorders did not predetermine an unsuccessful prophylaxis, 2/14 (14 percent). Blood loss, transfusion requirements and post-operative complications did not differ significantly between the two prophylactic groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of moisture on soil microorganisms and nematodes: A field experiment

The effects of soil moisture changes on bacteria, fungi, protozoa, and nematodes and changes in oxygen consumption were studied in a field experiment. In one plot the soil was drip-irrigated daily for 10 days, while an adjacent plot experienced one rainfall and was then allowed to dry out. Oxygen consumption was the parameter measured which responded most rapidly to changes in soil moisture content. Lengths of fluorescein diacetate-active hyphae paralleled oxygen consumption in both plots. Total hyphal length was not affected by one rainfall but increased from 700 mg(-1) dry weight soil to more than 1,600 m in less than 10 days in the irrigated plot. In the rain plot, bacterial numbers doubled within 3 days and declined during the following period of drought. In the irrigated plot, numbers increased by 50% and then remained constant over the duration of the study. Only small changes in protozoan numbers were observed, with the exception of the last sampling date in the irrigated plot when large numbers of naked amoebae were recorded 2 days after a large natural rainfall. Nematode numbers, especially obligate root feeders, increased in both treatments. The increases were caused by decoiling rather than growth. The results indicate that fungal respiration was dominating, while bacteria, lacking a suitable source of energy, were less active, except for the first days.

Mechanical and biochemical characterization of the contraction elicited by a calcium-independent myosin light chain kinase in chemically skinned smooth muscle

The contraction induced by a Ca2+-independent myosin light chain kinase (MLCK-) was characterized in terms of isometric force (Fo), immediate elastic recoil (SE), unloaded shortening velocity (Vus), shortening under a constant load and ATPase activity of chemically skinned smooth muscle preparations. These parameters were compared to those measured in a Ca2+ -induced contraction to assess the nature of cross bridge interaction in the MLCK-induced contraction. Fo developed in chicken gizzard fibers as well as SE were similar in contractions elicited by either agent. Vus in the contraction induced by MLCK-(0.36 mg/ml) was similar though averaged 39.3 +/- 8.9% less than Vus induced by Ca2+ (1.6 X 10(-6) M) in the control fibers. Addition of Ca2+ (1.6 X 10(-6) M) to a contraction induced by MLCK-resulted in small increases in both Fo and Vus. Shortening under a constant load was similar for both types of contractions. The contraction induced by MLCK-was accompanied by an increased rate of ATP hydrolysis. The MLCK-induced contraction is thus kinetically similar though not identical to a contraction induced by Ca2+. We conclude that with respect to actin-myosin interaction, MLCK-and Ca2+ -induced contractions are similar.

Reduced glucose incorporation to triglycerides following chronic exposure of human fat cells to growth hormone

Using the tissue culture technique we have recently demonstrated that long-term exposure of human adipose tissue to human growth hormone (GH) in vitro leads to an impairment in glucose incorporation into triglycerides. This effect was further studied in the present investigation. Biopsies of human adipose tissue which had been cultured for one week with or without GH were studied in subsequent short-term incubations where the conversion of glucose to CO2 and to total lipids was determined. The formation of CO2 was not changed by previous exposure of the biopsies to GH whereas the incorporation of glucose into triglycerides was reduced by about one third. Total glucose metabolism, as determined from the sum of the two pathways, was significantly reduced. The activities of three glycolytic enzymes were determined in biopsies of human adipose tissue which had been cultured with or without GH for one week. The activity of phosphofructokinase was reduced, while the hexokinase and the glucose-6-phosphate dehydrogenase activities were unchanged. The diminished activity of phosphofructokinase, the enzyme considered to be rate-limiting for glycolysis in human fat cells, may be responsible for the decreased rate of glucose metabolism found.

Human adipose tissue in culture V. Studies on the metabolic effects of insulin

Specimens of human adipose tissue were cultured for one week with or without the addition of insulin. The basal as well as the noradenaline-stimulated lipolysis were enhanced in the explants cultured with insulin, showing that the long-term effect of the hormone is lipolytic. However, an acute antilipolytic effect of insulin could be demonstrated in these explants in the subsequent short-term incubations. The basal rate of glucose incorporation into the lipids was enhanced in the explants cultured with insulin. When insulin was added in the short-term incubations these explants did not further respond to the hormone while this was the case with the explants cultured without insulin. Thus, it seems that prolonged exposure to insulin leads to a diminished acute effect of the hormone on glucose metabolism. However, the same explants responded to the antilipolytic effect showing that insulin was able to bind itself to the membrane. The activities of hexokinase (HK), glucose-6-phosphage dehydrogenase (G6PDH), pyruvate kinase (PK) and lactate dehydrogenase (LDH) were increased in large fat cells both in freshly excised tissue and in cultured explants. However, the activity of phosphofructokinase (PFK) did not correlate with the cell size. The presence of insulin during the culture period enhanced the activities of G7PDH, PK, and LDH, while this was not found for HK or PFK. The data thus suggest that the metabolic capacity of human fat cells is enhanced by long-term exposure to insulin. Although enzyme induction could be shown for G6PDH, PK and LDH it seems unlikely that this is of importance for the increased rates of glucose metabolism in these explants since the rate-limiting enzymes, HK and PGK, were not increased. Most probably, then, this stimulating effect of insulin is exerted on the membrane and the rate of glucose transport.