The role of the RAS in programming of adult hypertension.

The aetiology of cardiovascular disease originally included two components: a genetic component and an environmental or lifestyle component. Increasing epidemiologic evidence has been accumulating during the last decades indicating the importance of a third component: the influence of the environment during foetal development. Poor living conditions resulted in a high infant mortality and influenced the incidence of cardiovascular diseases in adulthood despite better living conditions (A. Forsdahl. Br J Prev Soc Med 1977; 31, 91-95). An association between pre-natal growth pattern and the rate of death from cardiovascular disease in adulthood was reported (D.J. Barker, P.D. Winter, C. Osmond, B. Margetts & S.J. Simmonds. Lancet 1989; 2, 577-580). Men from Hartfordshire (UK), born between 1911 and 1930 were investigated. The investigations showed that men with the lowest weight at birth and at 1 year of age had the highest risks of death from cardiovascular disease (D.J. Barker, P.D. Winter, C. Osmond, B. Margetts & S.J. Simmonds. Lancet 1989; 2, 577-580). These findings suggested that factors in the perinatal environment could programme an individual for later risk of development of cardiovascular disease compared with someone born with a normal weight. Numerous studies have since confirmed these initial findings of an inverse relationship between early growth pattern and cardiovascular disease in adulthood.

Nitric oxide synthase expression and enzymatic activity in human brain tumors.

Nitric oxide (NO) is synthesized by NO synthases (NOS), existing in 3 isoforms. NO influences a great variety of vital functions including vascular tone and neurotransmission. Under conditions of excessive formation, NO emerges as an important mediator of neurotoxicity in a variety of disorders of the central nervous system (CNS). Inhibitors of NOS are available that may modify the activity of all isoforms, which may be of clinical relevance. The expression of the 3 NOS isoforms nNOS, iNOS and eNOS and NOS enzymatic activity was examined in 40 patients with primary CNS tumors (gliomas WHO grades I - IV and meningeomas WHO grades I - III) and in 13 patients with metastases from adenocarcinomas or malignant melanomas. A polyclonal antibody directed against nNOS and monoclonal antibodies directed against iNOS and eNOS were used for immunohistochemical staining. NOS enzymatic activity, measured by labeled arginine to citrulline conversion, was assessed in tissue specimens obtained from the same tumors. NOS data were compared with clinical variables and the degree of edema as judged from MR scanning. nNOS expression was increased in tumor cells of glial neoplasms and most pronounced in high-grade tumors, WHO grades III and IV, and in the carcinoma and melanoma metastases. Low-grade gliomas, WHO grades I and II and meningeomas expressed no or only little nNOS. iNOS was only expressed in a few tumors. eNOS was expressed sporadically in the tumor cells while the expression was increased in vascular endothelial cells in both the tumor itself and the peritumoral area of glial neoplasms, and in metastases. eNOS expression was sporadic in endothelial cells of meningeomas. NOS enzymatic activities were heterogeneous among tumor types (0 - 13.8 pmol/min/mg of protein) without correlation to the NOS expression found by immunohistochemical techniques. Likewise, NOS activity and expression was not correlated to the clinical scores or brain edema. In conclusion, nNOS expression may be a putative useful indicator of brain tumor differentiation and malignancy. The enhanced expression of eNOS in vascular endothelial cells of glial neoplasms and metastases raises the possibility that NO production in tumor endothelial cells may contribute to tumor blood flow regulation and possibly brain edema.

Chlamydia pneumoniae-associated ADEM.

Inflammatory demyelinating diseases are a common cause of neurologic disability in young adults, and usually the cause is unknown. We describe a case of acute disseminated encephalomyelitis (ADEM) associated with Chlamydia pneumoniae infection. An 18-year-old previously healthy women, with a one-week history of coryzal illness, was admitted because of progressive headache, dizziness, and a left-sided hemiparesis. MR imaging of the brain and brainstem showed typical signs of ADEM. The diagnosis was established by PCR Chlamydia pneumoniae DNA positivity in a tracheal swab and by increasing titres of Chlamydia IgM antibody. The patient was treated with doxycycline and steroids and recovered completely. Apart from therapeutic implications, this case may contribute to our understanding of demyelinating diseases of the central nervous system.

[CT scanning in the diagnosis of internal carotid artery dissection]. / CT-scanning til påvisning af dissektion i a. carotis interna.

Dissection of the internal carotid artery is becoming more frequently recognized as a cause of neurological deficits or stoke in younger adults. A dissection is diagnosed in relation to minor often primarily unrecognized trauma to the neck and the typical clinical features seen with dissection are headache, Horner's syndrome and symptoms of focal brain ischaemia. Treatment, i.e. anti-coagulant therapy, is initiated to avoid thrombosis or recurrent embolism from the damaged arterial wall. The prognosis is generally good. The diagnosis of carotid dissection can be confirmed with ultrasound-duplex-scanning, conventional angiography or magnetic resonance imaging/angiography. In this paper two cases are reported in which computed tomography (CT-scanning) with intravenous contrast enhancement has been a valuable diagnostic tool in the diagnosis of this entity.

[Clinical value of SPECT scanning in children with neurological disorders]. / Den kliniske vaerdi af SPECT-scanning hos børn med neurologiske sygdomme.

We retrospectively evaluated the clinical value of Tc-99-HMPAO brain single photon emission tomography (SPECT) in 21 children with neurological disorders of varied aetiology. All 21 patients were examined with electroencephalograms (EEGs), 17 with computed tomography (CT) and ten with magnetic resonance imaging (MR). New relevant information was obtained from SPECT in all 21 cases and in four of these cases the investigation directly led to a change in diagnosis and better assessment of the prognosis. It is concluded that SPECT is an important investigational method in children with neurological symptoms of partly or completely unknown aetiology.

Gliomatosis cerebri--an appropriate diagnosis? Case reports.

PURPOSE: To evaluate the premises for the diagnosis gliomatosis cerebri in relation to diffuse astrocytomas. MATERIAL AND METHODS: CT, MR images and pathological analyses were used to assess the cases of 4 patients with diffusely infiltrating astrocytic tumours that radiologically, clinically and pathologically resembled gliomatosis cerebri. RESULTS AND CONCLUSION: Some astrocytomas have an immense potential for diffuse infiltration and they would seem to be more frequent than recognized hitherto. The definition of gliomatosis cerebri as a separate entity is questionable, and a diagnosis of diffusely infiltrating astrocytoma is recommended in such cases.

[CT of primary cerebral lymphoma in non-immunosuppressed patients]. / CT af primaert cerebralt lymfom hos ikkeimmunsupprimerede patienter.

In the last 10-15 years primary lymphoma of the brain has tripled in frequency in the non-immunosuppressed population. The correct diagnosis by CT-examination is difficult as primary lymphoma imitates different pathological conditions. Five examples from a series of 13 patients are presented.

Isolation and characterization of porcine mannan-binding proteins of different size and ultrastructure.

The authors report on the purification and characterization of mannan- binding proteins (MBP) isolated from porcine serum. The MBPs were purified by use of PEG precipitation, affinity chromatography on mannan-Sepharose, protein A- and anti-porcine IgM-Sepharose followed by gel filtration. The MBP proteins were collagenase sensitive and showed gamma 1-gamma 2-electrophoretic mobility. The MBP designated pMBP-28 had a molecular mass of 28 kDa when analysed on SDS-PAGE under reducing conditions and eluted corresponding to a molecular mass of approximately 700 kDa on gel filtration chromatography. Electron micrographs of pMBP-28 revealed an oligomeric protein similar to rodent MBP-A and human MBP but with a predominance of penta- and hexameric molecules. Another protein designated pMBP-27 was composed of peptides of 27 kDa and had an Mr of 300-350 kDa on gel filtration chromatography. Electron microscopy of pMBP-27 showed dimer and trimer molecules; the trimers without distinct stalk regions. The N-terminal 26(pMBP-27) and 24(MBP-28) amino acid residues showed 54% and 58% identity with human MBP.pMBP-28 showed a higher degree of sequence similarity to rat and mouse MBP-A (60% identity) than to mouse and rat MBP-C (41-45% identity). Both pMBPs exhibited Ca2+-dependent binding to D-mannose immobilized on agarose but no significant binding to N-acetyl-D-glucosamine- or fucose-agarose. The results further suggested the presence of a third pMBP which copurified with pMBP-27 but this protein was not sequenced.

Does nimodipine influence sex difference in outcome after aneurysmal subarachnoid haemorrhage?

Before nimodipine was introduced as a standard treatment in patients with aneurysmal subarachnoid haemorrhage (SAH) females had a significantly poorer outcome which might be due to a higher frequency of delayed cerebral ischaemia (DCI). We evaluated the overall outcome with regard to gender in 188 consecutive patients with a verified ruptured intracranial aneurysm treated with nimodipine. The only significant differences concerning prognostic factors between the sexes were a higher frequency of SAH at the primary CT in female (p < 0.05) and a higher frequency of middle cerebral artery aneurysms in females (p < 0.01). These factors affect the outcome in females unfavourably. However, contrary to previous studies, we found no difference in overall outcome after three months between the sexes in this clinical material. Our observation can be explained by a positive effect of nimodipine on DCI.

Mannan-binding protein forms complexes with alpha-2-macroglobulin. A protein model for the interaction.

We report that alpha-2-macroglobulin (alpha 2M) can form complexes with a high molecular weight porcine mannan-binding protein (pMBP-28). The alpha 2M/pMBP-28 complexes was isolated by PEG-precipitation and affinity chromatography on mannan-Sepharose, protein A-Sepharose and anti-IgM Sepharose. The occurrence of alpha 2M/pMBP-28 complexes was further indicated by crossed immunoelectrophoresis and by use of an anti-alpha 2M affinity column and chelating Sepharose loaded with Zn2+. The eluates from these affinity columns showed alpha 2M subunits (94 and 180 kDa) and pMBP subunits (28kDa) in SDS-PAGE, which reacted with antibodies against alpha 2M and pMBP-28, respectively, in Western blotting. Furthermore, alpha 2M/pMBP-28 complexes were demonstrated by electron microscopy. Fractionation of pMBP-containing D-mannose eluate from mannan-Sepharose on Superose 6 showed two protein peaks which reacted with anti-C1 s antibodies in ELISA, one of about 650-800 kDa, which in addition contained pMBP-28 and anti-alpha 2M reactive material, the other with an M(r) of 100-150 kDa. The latter peak revealed rhomboid molecules (7 x 15 nm) in the electron microscope and a 67 kDa band in SDS-PAGE under reducing conditions. This band was also seen in eluates from the anti-alpha 2M and chelating Sepharose columns. Based on these observations and previous findings by other investigators of a serine protease with about 67 kDa subunits which copurifies with human MBP we propose a model for the interaction of pMBP-28 with alpha 2M.

Collectin in a non-mammalian species: isolation and characterization of mannan-binding protein (MBP) from chicken serum.

A chicken serum lectin was isolated by affinity chromatography on TSK-75 beads derivatized with the monosaccharide N-acetyl-D-mannosamine (ManNAc). Serum was applied to the column in a Ca(2+)-containing buffer and proteins were eluted with EDTA. After recalcification, the eluate was passed through a new ManNAc-derivatized column. Bound proteins were eluted with 50 mM ManNAc. Anti-carbohydrate antibodies present in the eluate were removed by passage through a rabbit anti-chicken immunoglobulin derivatized column, and the lectin was further purified by ion-exchange chromatography and gel-permeation chromatography. The purified chicken lectin shows an overall structure similar to mammalian mannan-binding protein (MBP). SDS-PAGE revealed two polypeptides of M(r) 33 and 34 kDa (reduced) with identical sequence for the first 30 NH2-terminal residues. The NH2-terminal sequence shows 43% identity with the human MBP. Like mammalian MBP, the polypeptides of the chicken lectin are degraded by treatment with collagenase. Residues 26-30 (G-L-P(OH)-G-D) are likely to represent the beginning of the collagenous region. Mobilities on SDS-PAGE of the COOH-terminal collagenase-resistant fragment under reduced and non-reduced conditions indicate the presence of intrachain disulphide bonds, as are also found in mammalian MBP. Gel chromatography showed an intact mol. wt of 750 kDa. Binding of the chicken MBP to mannan was inhibited by monosaccharides in the following order of potency: ManNAc > L-fucose > mannose > N-acetylglucosamine. Other monosaccharides inhibited poorly or not at all. Chicken MBP, bound to mannan, activated the classical complement pathway in human serum. Electron micrographs show structures and dimensions resembling human MBP. Overall, the results show that the purified lectin is the chicken homologue to mammalian MBP and indicate the presence of a MBP-like clearance system outside mammals.

[Iatrogenic rhinolithiasis?]. / Iatrogen rinolit?

A case of rhinolithiasis in a young man is presented. The radiological (CT-scan) and clinical findings of a rhinolith may be similar to other benign or malignant nasal lesion such as inverted papilloma. This similarity and the possibility that a rhinolith may have iatrogen origin is presented in this article.

CT demonstration of prostatic zonal anatomy during dynamic contrast infusion.

CT of the pelvis was made after i.v. administration of 100 ml Omnipaque (300 mg I/ml) in 8 patients. The 1st series postcontrast was obtained dynamically and the 2nd 5 to 15 min after injection. Postcontrast enhancement of the prostate was shown in all patients. Dynamic contrast-enhanced CT was better than delayed postcontrast CT in showing the zonal anatomy in 6 patients. The method might be useful in patients where transrectal ultrasound is not applicable and when MR is not available.

Oligomer formation of staphylococcal alpha-toxin analyzed by electron microscopy and image processing.

The 12S oligomeric form of Staphylococcus aureus alpha-toxin has been studied with electron microscopy after incubation of the toxin with membrane preparations or liposomes. The target material originated from human platelets. Different electron microscopic preparation techniques were used including negative staining, freeze-fracture and vitrification in liquid ethane. Analysis of micrographs with image processing methods revealed two groups of ring-like structures corresponding to alpha-toxin oligomers. One form measured 75 A in diameter and had a high stain density in the central protein deficient part while the other was larger with a diameter of 100 A and less stain accumulation in the center. The conditions under which the latter were formed suggest that this corresponds to an inactive loosely-bound form of the toxin. The high stain density in the smaller particle is consistent with the presence of a penetrating pore in this structure.

[Cerebral toxoplasmosis primarily diagnosed as a tumor]. / Cerebral toksoplasmose primaert diagnosticeret som tumor.

Three cases of cerebral toxoplasmosis as the presenting manifestation of AIDS are reported. The initial diagnoses were brain tumors because of the cerebral mass lesions which resembled glioblastoma. In the light of the increasing occurrence of AIDS, attention is drawn to cerebral toxoplasmosis as a differential diagnosis from glioblastoma multiforme.

Three-dimensional structure of Na,K-ATPase determined from membrane crystals induced by cobalt-tetrammine-ATP.

The three-dimensional structure of Na,K-ATPase has been analyzed with electron microscopy and image processing. The enzyme, purified from pig kidney outer medulla, was arranged in a new form of tetragonal two-dimensional membrane crystals after incubation with cobalt-tetrammine-ATP, a stable MgATP complex analogue. Each continuous protein domain, as delineated by negative stain, consists of two alpha beta-protomers related by a dyad axis. The two rod-like regions are connected by a bridge displaced about 20 A away from the center of the structure toward the lipid bilayer. The domain connecting the two promoters is more constricted and closer to the center of the structure in the Co(NH3)4ATP-induced crystals than in the vanadate-induced p21 crystals. These observations suggest that the difference between previously analyzed dimers of two-dimensional p21 crystals induced with vanadate/magnesium and dimers of p4 crystals induced with Co(NH3)4ATP reflects two different conformational states of the enzyme.