Ceftriaxone Absorption Enhancement for Noninvasive Administration as an Alternative to Injectable Solutions.

Neonatal sepsis is a major cause of infant mortality in developing countries because of delayed injectable treatment, making it urgent to develop noninjectable formulations that can reduce treatment delays in resource-limited settings. Ceftriaxone, available only for injection, needs absorption enhancers to achieve adequate bioavailability via nonparenteral administration. This article presents all available data on the nonparenteral absorption of ceftriaxone in humans and animals, including unpublished work carried out by F. Hoffmann-La Roche (Roche) in the 1980s and new data from preclinical studies with rabbits, and discusses the importance of these data for the development of noninjectable formulations for noninvasive treatment. The combined results indicate that the rectal absorption of ceftriaxone is feasible and likely to lead to a bioavailable formulation that can reduce treatment delays in neonatal sepsis. A bile salt, chenodeoxycholate sodium salt (Na-CDC), used as an absorption enhancer at a 125-mg dose, together with a 500-mg dose of ceftriaxone provided 24% rectal absorption of ceftriaxone and a maximal plasma concentration of 21 µg/ml with good tolerance in human subjects. The rabbit model developed can also be used to screen for the bioavailability of other formulations before assessment in humans.

A new fish cell line derived from the caudal fin of freshwater angelfish Pterophyllum scalare: development and characterization.

In this study, a new cell line derived from the caudal fin of the freshwater angelfish Pterophyllum scalare was developed and characterized. The cell line was designated angelfish fin (AFF) and subcultured 44 times since its development. These cells grew well in Leibovitz's -15 medium supplemented with 10% foetal bovine saline (FBS) at 28° C and the modal chromosome number (2n) was 48. The AFF cell-line is mainly comprised of epithelial cells as confirmed by immunocytological technique using anti-cytokeratin antibodies, an epithelial cell marker. This cell line was tested for growth in a temperatures range from 20 to 37° C and at various FBS concentrations of 5-20% at 28° C. The cell line was cryopreserved at different passage levels and revived successfully with 80% survival rate. Polymerase chain reaction amplification and sequencing of partial mitochondrial 16s rRNA and coI genes confirmed that the AFF cell-line originated from angelfish. Mycoplasma sp. contamination was not detected in AFF cells and checked by Hoechst 33258 fluorescence staining. At the 42nd passage the cells were transfected with 2 µg of pAcGFP1-N1 expression vector. The AFF cells exhibited cytotoxic effects when exposed to the bacterial extra cellular products from Serratia marcescens and Proteus hauseri. The AFF cells and cells from kidney and brain did not show cytopathic effect when exposed to cyprinid herpes virus2 and viral nervous necrosis virus. The newly developed AFF cell line will be useful for the isolation of viruses affecting angelfishes, such as iridoviruses, in the future.

Inhibition of apoptotic Bax translocation to the mitochondria is a central function of parkin.

Parkinson's disease (PD) is the second most prevalent neurodegenerative disorder, affecting 1-3% of the population over 65. Mutations in the ubiquitin E3 ligase parkin are the most common cause of autosomal recessive PD. The parkin protein possesses potent cell-protective properties and has been mechanistically linked to both the regulation of apoptosis and the turnover of damaged mitochondria. Here, we explored these two functions of parkin and the relative scale of these processes in various cell types. While biochemical analyses and subcellular fractionation were sufficient to observe robust parkin-dependent mitophagy in immortalized cells, higher resolution techniques appear to be required for primary culture systems. These approaches, however, did affirm a critical role for parkin in the regulation of apoptosis in primary cultured neurons and all other cells studied. Our prior work demonstrated that parkin-dependent ubiquitination of endogenous Bax inhibits its mitochondrial translocation and can account for the anti-apoptotic effects of parkin. Having found a central role for parkin in the regulation of apoptosis, we further investigated the parkin-Bax interaction. We observed that the BH3 domain of Bax is critical for its recognition by parkin, and identified two lysines that are crucial for parkin-dependent regulation of Bax translocation. Last, a disease-linked mutation in parkin failed to influence Bax translocation to mitochondria after apoptotic stress. Taken together, our data suggest that regulation of apoptosis by the inhibition of Bax translocation is a prevalent physiological function of parkin regardless of the kind of cell stress, preventing overt cell death and supporting cell viability during mitochondrial injury and repair.

Thorectandrols A and B, new cytotoxic sesterterpenes from the marine sponge Thorectandra species.

Two new sesterterpenes, thorectandrol A (1) and B (2), were isolated from extracts of the marine sponge Thorectandra sp. The structures were determined by extensive NMR spectral data analysis. NOE correlations were used to define the relative stereochemistry of 1 and 2, while CD data were used to suggest their absolute stereochemistry. Both compounds 1 and 2 inhibited the growth of MALME-3M (melanoma) and MCF-7 (breast) cancer cell lines in the range 30-40 microg/mL. The known compound palauolol (3) was isolated as well and was also cytotoxic.

Conquering a culture of indecision.

The single greatest cause of corporate underperformance is the failure to execute. Author Ram Charan, drawing on a quarter century of observing organizational behavior, perceives that such failures of execution share a family resemblance: a misfire in the personal interactions that are supposed to produce results. Faulty interactions rarely occur in isolation, Charan says. Far more often, they're typical of the way large and small decisions are made or not made throughout the organization. The inability to take decisive action is rooted in a company's culture. But, Charan notes, leaders create a culture of indecisiveness, and leaders can break it. Breaking it requires them to take three actions. First, they must engender intellectual honesty in the connections between people. Second, they must see to it that the organization's "social operating mechanisms"--the meetings, reviews, and other situations through which people in the corporation do business--have honest dialogue at their cores. And third, leaders must ensure that feedback and follow-through are used to reward high achievers, coach those who are struggling, and discourage those whose behaviors are blocking the organization's progress. By taking these three approaches and using every encounter as an opportunity to model open and honest dialogue, a leader can set the tone for an organization, moving it from paralysis to action.

Isolation and characterization of Myrianthus holstii lectin, a potent HIV-1 inhibitory protein from the plant Myrianthus holstii(1).

Aqueous extracts from the African plant Myrianthus holstii potently inhibited the infection of the T-lymphoblastoid cell line, CEM-SS, by human immunodeficiency virus-1(RF) (HIV-1(RF)). The active constituent, M. holstii lectin (MHL), was purified by LH-20 column chromatography and reversed phase HPLC. MHL, a 9284-Da cysteine-rich protein, was characterized by amino acid analysis, N-terminal sequencing, ESIMS, and matrix-assisted laser-desorption ionization-time-of-flight mass spectrometry. Pure MHL had anti-HIV activity, with an EC(50) value of 150 nM. Delaying the addition of MHL for up to 8 h after initial exposure of CEM-SS cells to virus did not result in loss of the antiviral activity; however, if addition of the compound was delayed for 16 h or more, there was a marked decrease in the antiviral activity. MHL bound to a virus-free, soluble form of the viral envelope protein gp120 but did not inhibit the subsequent binding to a cell-free, soluble form of the cellular receptor CD4.

A sponge/dinoflagellate association in the haplosclerid sponge Haliclona sp.: cellular origin of cytotoxic alkaloids by percoll density gradient fractionation.

Light-microscopic and electron-microscopic studies of the tropical marine sponge Haliclona sp. (Order: Haplosclerida; Family: Haliclonidae) from Heron Island, Great Barrier Reef, have revealed that this sponge is characterized by the presence of dinoflagellates and by nematocysts. The dinoflagellates are 7-10 micrometer in size, intracellular, and contain a pyrenoid with a single stalk, whereas the single chloroplast is branched, curved, and lacks grana. Mitochondria are present, and the nucleus is oval and has distinct chromosomal structure. The dinoflagellates are morphologically similar to Symbiodinium microadriaticum, the common intracellular symbiont of corals, although more detailed biochemical and molecular studies are required to provide a precise taxonomic assignment. The major sponge cell types found in Haliclona sp. are spongocytes, choanocytes, and archaeocytes; groups of dinoflagellates are enclosed within large vacuoles in the archaeocytes. The occurrence of dinoflagellates in marine sponges has previously been thought to be restricted to a small group of sponges including the excavating hadromerid sponges; the dinoflagellates in these sponges are usually referred to as symbionts. The role of the dinoflagellates present in Haliclona sp. as a genuine symbiotic partner requires experimental investigation. The sponge grows on coral substrates, from which it may acquire the nematocysts, and shows features, such as mucus production, which are typical of some excavating sponges. The cytotoxic alkaloids, haliclonacyclamines A and B, associated with Haliclona sp. are shown by Percoll density gradient fractionation to be localized within the sponge cells rather than the dinoflagellates. The ability to synthesize bioactive compounds such as the haliclonacyclamines may help Haliclona sp. to preserve its remarkable ecological niche.

Cellular origin of chlorinated diketopiperazines in the dictyoceratid sponge Dysidea herbacea (Keller).

The tropical marine sponge Dysidea herbacea (Keller) contains the filamentous unicellular cyanobacterium Oscillatoria spongeliae (Schulze) Hauck as an endosymbiont, plus numerous bacteria, both intracellular and extracellular. Archaeocytes and choanocytes are the major sponge cell types present. Density gradient centrifugation of glutaraldehyde-fixed cells with Percoll as the support medium has been used to separate the cyanobacterial symbiont from the sponge cells on the basis of their differing densities. The protocol also has the advantage of separating broken from intact cells of O. spongeliae. The lighter cell preparations contain archaeocytes and choanocytes together with damaged cyanobacterial cells, whereas heavier cell preparations contain intact cyanobacterial cells, with less than 1% contamination by sponge cells. Gas chromatography/mass spectrometry analysis has revealed that the terpene spirodysin is concentrated in preparations containing archaeocytes and choanocytes, whereas nuclear magnetic resonance analysis of the symbiont cell preparations has shown that they usually contain the chlorinated diketopiperazines, dihydrodysamide C and didechlorodihydrodysamide C, which are the characteristic metabolites of the sponge/symbiont association. However, one symbiont preparation, partitioned by a second Percoll gradient, has been found to be devoid of chlorinated diketopiperazines. The capability to synthesize secondary metabolites may depend on the physiological state of the symbiont; alternatively, there may be two closely related cyanobacterial strains within the sponge tissue.

The incidence of retinopathy of prematurity in a neonatal care unit.

In India, with advancement in neonatal care units, a large number of low-birth weight premature babies are now surviving and are at risk of developing retinopathy of prematurity (ROP). However, there are not enough reports on the incidence of ROP in this country. To determine the incidence of ROP in a prospective manner, 165 babies weighing < or = 1700 gm over a period of one year were examined. An incidence of 47.27% of ROP at the mean age of 7.21 +/- 0.3 weeks of life was detected. The maximum stage reached was stage 1 in 28 (16.97%), stage 2 in 29 (17.58%), stage 3 in 19 (11.52%) and stage 4b in 2 (1.21%) babies. Plus disease was present in 17 (10.3%) babies. Babies with lower birth weights and lower gestation age at birth had a significantly higher (p = < 0.05) incidence of ROP. However, the difference in mean birth weight and gestation age at birth for various stages of ROP was not significant (p = > 0.05). Thus, we recommend screening for all babies weighing < or = 1700 gm.

How networks reshape organizations--for results.

Recently a new term-networks-has entered the vocabulary of corporate renewal. Yet there remains much confusion over just what networks are and how they operate. Ram Charan, a leading international consultant, has spent four years observing and participating in the creation of networks at ten companies in North America and Europe. These companies--which include Conrail, Dun & Bradstreet Europe, Du Pont, and Royal Bank of Canada-are clear about why they are creating networks, what networks are, and how they operate. A network is recognized group of managers (seldom more than 100, often fewer than 25) assembled by the CEO. Membership criteria are simple but subtle: What select group of managers, by virtue of its business skills, personal motivations and drive, and control of resources is uniquely positioned to shape and deliver on the strategy? Networks begin to matter when they change behavior-the frequency, intensity, and honesty of the dialogue among managers on priority tasks. The process of building a network starts at the top. Senior managers work as change agents to build a new "social architecture." Once the network is in place, they play three additional roles: 1. Define with clarity the business outputs they expect of the network and the time frame in which they expect it to deliver. 2. Guarantee the visibility and free flow of information to all members of the network who need it. 3. Develop new criteria for performance evaluation that emphasize horizontal collaboration and leadership.

Physicochemical hair conformation of patients with Sanfilippo disease type IIIA.

Sanfilippo disease type IIIA is an inborn error of metabolism with a deficiency in the heparan sulfamidase. Besides severe psychomotor retardation hair changes are obligatory. Hair is found to be coarse like a brush. We applied X-ray diffraction and infrared spectroscopy to characterize the conformation of hair samples of Sanfilippo patients. In healthy subjects as well as in the affected hair samples we found the wave numbers of structural relevance 1450, 1500, 1630, 1730, the pair 2337 and 2362, the quadruplet 2850, 2870, 2917, 2930 and 3080 cm-1. Also on X-ray diffraction analysis no differences could be detected. Though morphological-macroscopically and microscopically-changes were described for Sanfilippo hair samples, we could not find any change in supramolecular structure. The physical properties of coarseness of those hair specimen seems to be due to differences in the structural assembly of hair fibres and storage of heparan sulfate.