Therapeutical efficacy of a novel chloride transport blocker and an IP3-analogue in vasogenic brain edema

The efficacy of torasemide, a novel chloride-channel blocker, and of PP56, an IP3 analogue, was currently examined in experimental brain edema. Following trephination in anesthesia rats were subjected to a focal cold injury of the left cerebral hemisphere. Animals of 4 experimental groups receiving either torasemide (i.v. at 30 min before and 6 h after lesion) or PP56 (continuous infusion beginning at 30 min before until 24 h after lesion) at two dose levels were compared with controls administered with i.v. saline. 24 h after trauma the brain was removed from the skull, and the hemispheres were separated in the median plane for gravimetric assessment of hemispheric swelling. Hct, blood gases and body temperature remained constant in all groups. Blood pressure was found to increase in a dose-dependent manner in animals with torasemide. No significant reduction of brain swelling was found in animals with low-dose torasemide (8.51 +/- 0.63%) or low- (7.91 +/- 0.60) and high-dose PP56 (6.85 +/- 1.05%) as compared to the untreated controls. Brain swelling, however, was significantly attenuated by high-dose torasemide to 7.04 +/- 0.36%, as compared to 8.89 +/- 0.29% of the untreated group (p < 0.005). It is currently studied whether torasemide reduces brain swelling when given after the insult.

7.2% NaCl/10% dextran 60 versus 20% mannitol for treatment of intracranial hypertension

Severe head injury is frequently associated with extracranial injuries causing hemorrhagic hypotension. Volume replacement with isotonic fluids not only is therapeutically of limited efficacy but may aggravate posttraumatic brain edema. On the other side, hypertonic/hyperoncotic saline/dextran solution (HHS) shown to restore cardiovascular function in hemorrhagic shock instantaneously, was found to decrease intracranial pressure in experimental head injury. Currently the therapeutic efficacy of HHS and mannitol on ICP was compared at 24 hrs after a focal cerebral lesion and inflation of an epidural balloon in rabbits. Both solutions given at an equimolar dose rapidly lowered the ICP. After the first injection, ICP reduction was longer maintained with mannitol (189 +/- 27 min) as compared to HHS (98 +/- 14 min), while no difference in duration of lowering ICP was found after the second injection. Due to its blood pressure effects, HHS afforded a higher cerebral perfusion pressure than mannitol. In animals with HHS, the water content of the traumatized hemisphere was increased while the contralateral hemisphere was dehydrated. With mannitol, no differences in water content were found between the injured and uninjured hemisphere. The efficiency of HHS in hemorrhagic shock and intracranial hypertension render the fluid mixture particularly promising in patients with polytrauma in combination with head injury.

Effects of isoflurane, fentanyl, or thiopental anesthesia on regional cerebral blood flow and brain surface PO2 in the presence of a focal lesion in rabbits

These studies were conducted to determine the effect of anesthetic drugs on tissue perfusion and O2 supply in the brain with focal cerebral edema. Using an open cranium preparation, we studied the effects of isoflurane (I; 1 minimum alveolar anesthetic concentration), of fentanyl (F; 0.5-1 microgram.kg-1 x min-1), or of thiopental (T; 32.5 mg.kg-1 x h-1) on regional cerebral blood flow (rCBF) and regional brain tissue PO2 in albino rabbits (n = 6 per group) with a focal brain lesion (cold injury). The doses of anesthetics were sufficient to suppress nociception. rCBF (H2 clearance) and tissue PO2 (multiwire surface electrode) were studied adjacent to and distant from the lesion. Cerebral hyperemia developed immediately after trauma in all groups, although the flow increase did not attain statistical significance. rCBF was subsequently reduced by about 25% in the vicinity of the lesion. Distant from the trauma, a continuing hyperemia (+30%) was later observed in animals with isoflurane, whereas rCBF was decreased then by 10%-20% in animals with fentanyl, or was unchanged with thiopental. Brain tissue PO2 was increased with isoflurane in areas distant from the lesion, but decreased with fentanyl. However, with thiopental, the PO2 level had already been lowered before trauma with a subsequent tendency toward normalization. The heterogeneity of the tissue PO2 in fentanyl anesthesia, as well as the increased frequency of hypoxic PO2 values with thiopental, might have resulted from microcirculatory disturbances. Thus, although isoflurane seemed to facilitate hyperemia with an increased O2 supply to the brain, fentanyl tended to induce the opposite response. Although these properties suggest the potential to manipulate perfusion and O2 supply in cerebral ischemia or hyperemia after head injury, the effects of such measures on intracranial pressure, neurologic status, and outcome have yet to be proven.

ADA3: a gene, identified by resistance to GAL4-VP16, with properties similar to and different from those of ADA2

We describe the isolation of a yeast gene, ADA3, mutations in which prevent the toxicity of GAL4-VP16 in vivo. Toxicity was previously proposed to be due to the trapping of general transcription factors required at RNA polymerase II promoters (S. L. Berger, B. Piña, N. Silverman, G. A. Marcus, J. Agapite, J. L. Regier, S. J. Triezenberg, and L. Guarente, Cell 70:251-265, 1992). trans activation by VP16 as well as the acidic activation domain of GCN4 is reduced in the mutant. Other activation domains, such as those of GAL4 and HAP4, are only slightly affected in the mutant. This spectrum is similar to that observed for mutants with lesions in ADA2, a gene proposed to encode a transcriptional adaptor. The ADA3 gene is not absolutely essential for cell growth, but gene disruption mutants grow slowly and are temperature sensitive. Strains doubly disrupted for ada2 and ada3 grow no more slowly than single mutants, providing further evidence that these genes function in the same pathway. Selection of initiation sites by the general transcriptional machinery in vitro is altered in the ada3 mutant, providing a clue that ADA3 could be a novel general transcription factor involved in the response to acidic activators.

Immunopurification of a subcomplex of the NAD(P)H-plastoquinone-oxidoreductase from the cyanobacterium Synechocystis sp. PCC6803

An antibody against the NDH-K subunit of the NAD(P)H-dehydrogenase from the cyanobacterium Synechocystis sp. PCC6803 was used to isolate a subcomplex of the enzyme from Triton X-100 solubilized total membranes by immunoaffinity chromatography. The isolated subcomplex consisted of seven major polypeptides with molecular masses of 43, 27, 24, 21, 18, 14 and 7 kDa. The amino-terminal amino acid sequences of the polypeptides were determined. By comparing the sequences with the amino acid sequences deduced from DNA, three proteins were identified as NDH-H (43 kDa), NDH-K (27 kDa) and NDH-I (24 kDa). A fourth subunit (NDH-J, 21 kDa) was identified by Western blot analysis with an NDH-J antibody.

Anaerobic bacteremia: a retrospective four-year analysis in general medicine and cancer patients

Anaerobic bacteremia was studied in 32 medical patients (mean age 72 years) in a four-year retrospective analysis. Malignancy was the most common underlying disease and probable portal of entry. The gastrointestinal tract was affected most often, followed by the respiratory and urinary tracts. Bacteremia occurred either following invasive (non surgical) procedures or spontaneously. The clinical course ranged from asymptomatic bacteremia, to mild febrile illness, to sepsis and septic shock (two, 12, 16 and two patients, respectively). The case fatality rate was 25%. The causative organisms were Clostridium and Bacteroides species. All organisms isolated were susceptible to chloramphenicol. Early diagnosis and prompt treatment may reduce mortality in cases of anaerobic sepsis.

Giving employers what they want. Successful CEOs read warning signs

Corporate executives are becoming activists in challenging the fundamentals of the healthcare delivery system and in developing standards for selective contracting. The actions they take could drive many providers from the market.

[Lymphocytoma cutis]

Three patients with skin lymphocytoma and different histologic and clinical appearance of lesions (solitary, grouped, and in the third patient one lesion appeared on the forehead and one on the neck) are presented. By the histologic analysis and the use of immunohistochemical methods the differentiation of these lesions from skin lymphoma and other diseases which could resembe lymphocytoma was made. The method of immunoperoxidase has clearly shown formation of follicules and polyclonal lymphocytes which is the main histologic feature of this pseudolymphoma. By the method of indirect immunofluorescence, antibodies against Borrelia burgorferi were not found in the sera of two patients while in the third it was not performed.

Alepposides, cardenolide oligoglycosides from Adonis aleppica

The structures of novel oligoglycosidic cardenolides, alepposide A (C55H86O23) [1] and alepposide B (C48H74O20) [2], have been deduced mainly by nmr methods. Based on homonuclear (1H and 13C nmr, 1H COSY) and proton-detected heteronuclear shift correlation experiments [HMQC both for 1J(C,H) and for long-range couplings], alepposide A [1] was shown to have the structure strophanthidin-3-O-beta-glucopyranosyl-(1-->4)-O-beta-diginopyranosyl -(1-->4)-O - beta-oleandropyranosyl-(1-->4)-O-beta-digitoxopyranosyl-(1-- >4)-O-beta- digitoxopyranoside. The structure of alepposide B [2] was established as strophanthidin-3-O-beta-glucopyranosyl-(1-->4)-O-beta-oleandropyranos yl- (1-->4)-O-beta-digitoxopyranosyl-(1-->4)-O-beta-digitoxopyranos ide.

Relationship of cerebral blood flow disturbances with brain oedema formation

Brain oedema is an important factor which compromises maintenance of the cerebral blood flow. Conversely, primary blood flow disturbances are leading to brain oedema. The mechanisms underlying blood flow impairment by brain oedema are associated with an increased regional tissue pressure in proportion to the degree of water accumulation in the parenchyma. The release of vasoactive mediator compounds might be considered in addition. Primary disturbances of the cerebral blood flow, such as focal or global cerebral ischaemia are leading to an increased cerebral water content. A decrease of the cerebral blood flow to ca. 40% of normal or below has been found to result in the development of brain oedema. This flow threshold is in the neighbourhood of the ischaemic flow level causing irreversible tissue damage. Whereas in focal ischaemia oedema formation is a function of the severity of the flow decrease, it is a pathophysiological hallmark of early postischaemic recirculation in global cerebral ischaemia. Nevertheless, during complete interruption of cerebral blood flow translocation of interstitial fluid into the intracellular compartment occurs as manifestation of ischaemic cell swelling. Cell swelling under these conditions may, however, not necessarily indicate cell damage, but more likely a compensatory response attributable to the uptake of excitotoxic transmitters such as glutamate, and of K(+)-ions which are excessively released at the onset of ischaemia into the extracellular space. Purpose of the swelling process, thus, is clearance of extracellular fluid from this material to re-establish homeostasis.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution and infection of Langerhans cells in the skin of HIV-infected healthy subjects and AIDS patients

The in situ content of cells of the reticuloendothelial system and lymphatic cells was examined in the skin of eight symptom-free HIV-positive individuals, three AIDS patients and eleven healthy immunocompetent volunteers. The epidermis was obtained in vivo by the suction blister technique. The numbers of CD68+, CD3+, CD8+, CD25-(IL2R)+ and HLA-DR+ intraepidermal cells proved to be independent of the number of CD4+ peripheral blood lymphocytes. At the same time, the intraepidermal concentrations of these cells were generally low in symptom-free HIV-infected individuals. The strong inverse correlation between the number of epidermal Langerhans cells (LC) and the severity of immunodeficiency was quantitatively confirmed; an increase in LC in symptom-free HIV-infected individuals was found. Thus, the reduction in these cells which was observed in the epidermis of AIDS patients began at a significantly elevated level. In contrast to results from other studies, in AIDS patients, in the present study, the concentration of epidermal LC did not differ significantly from that of healthy immunocompetent volunteers. The immunohistochemical technique can be as effective as in situ hybridization for the detection of HIV in the skin. Our results suggest that the viral load of the skin is rather low in HIV-infected subjects. HIV was demonstrated in one cell of one AIDS case by in situ techniques and this result was confirmed by a polymerase chain reaction examination using the same amount of tissue as for the in situ techniques.(ABSTRACT TRUNCATED AT 250 WORDS)

The redox-controlled light-harvesting chlorophyll a/b protein kinase. Deactivation by substituted quinones

The deactivation of the redox-controlled light-harvesting chlorophyll a/b protein kinase of Acetabularia acetabulum and pea thylakoids was studied. Substituted benzoquinone, naphthoquinone, and anthraquinone analogs including mono-, di-, and trihalogenated and/or alkylated quinones, which are known to inhibit the cytochrome b6/f activity, deactivate the kinase in the dark, and prevent its activation in the light. Analogs halogenated at positions 2- or 3- are the most effective deactivators. Increasing the size of the alkyl side chain and/or the number of rings lowers the deactivation effect. The activated state of the pea kinase decays with a t1/2 of 15 min, while the Acetabularia enzyme retains its active state for at least 2 h. The midpoint potential for Acetabularia kinase activity in the dark is 120 +/- 10 mV and is compatible with the involvement of plastoquinone in the kinase activation via reduction of the cytochrome complex. Deactivation of kinase by the analogs inhibiting cytochrome b6/f complex activity and the kinase copurification with the cytochrome b6/f fraction obtained from the Acetabularia thylakoid further support this conclusion. These results indicate that the process of kinase activation/deactivation includes the binding of plastoquinol or quinone analogs by the cytochrome complex and its interaction with the kinase. We propose that the latter process may constitute the rate-limiting step controlling the kinase activation/deactivation kinetics.

Attracting good managed-care plans that deliver on promises

Imagine it's the year 2000. Managed care accounts for nearly 50% of your hospital's patient revenues. Are you prepared? Are you pursuing the more desirable managed-care organizations while staying clear of those that fail to deliver on promises? Consultants Sally Berger and Diane Millikan offer advice to help facilities woo top-notch managed-care plans and thereby increase their market shares.